To see the other types of publications on this topic, follow the link: Arctic lake.
Journal articles on the topic 'Arctic lake'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Arctic lake.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Lara, Mark Jason, and Melissa Lynn Chipman. "Periglacial Lake Origin Influences the Likelihood of Lake Drainage in Northern Alaska." Remote Sensing 13, no. 5 (February 25, 2021): 852. http://dx.doi.org/10.3390/rs13050852.
Full textAbstract:
Nearly 25% of all lakes on earth are located at high latitudes. These lakes are formed by a combination of thermokarst, glacial, and geological processes. Evidence suggests that the origin of periglacial lake formation may be an important factor controlling the likelihood of lakes to drain. However, geospatial data regarding the spatial distribution of these dominant Arctic and subarctic lakes are limited or do not exist. Here, we use lake-specific morphological properties using the Arctic Digital Elevation Model (DEM) and Landsat imagery to develop a Thermokarst lake Settlement Index (TSI), which was used in combination with available geospatial datasets of glacier history and yedoma permafrost extent to classify Arctic and subarctic lakes into Thermokarst (non-yedoma), Yedoma, Glacial, and Maar lakes, respectively. This lake origin dataset was used to evaluate the influence of lake origin on drainage between 1985 and 2019 in northern Alaska. The lake origin map and lake drainage datasets were synthesized using five-year seamless Landsat ETM+ and OLI image composites. Nearly 35,000 lakes and their properties were characterized from Landsat mosaics using an object-based image analysis. Results indicate that the pattern of lake drainage varied by lake origin, and the proportion of lakes that completely drained (i.e., >60% area loss) between 1985 and 2019 in Thermokarst (non-yedoma), Yedoma, Glacial, and Maar lakes were 12.1, 9.5, 8.7, and 0.0%, respectively. The lakes most vulnerable to draining were small thermokarst (non-yedoma) lakes (12.7%) and large yedoma lakes (12.5%), while the most resilient were large and medium-sized glacial lakes (4.9 and 4.1%) and Maar lakes (0.0%). This analysis provides a simple remote sensing approach to estimate the spatial distribution of dominant lake origins across variable physiography and surficial geology, useful for discriminating between vulnerable versus resilient Arctic and subarctic lakes that are likely to change in warmer and wetter climates.
2
Kuhn, Catherine, and David Butman. "Declining greenness in Arctic-boreal lakes." Proceedings of the National Academy of Sciences 118, no. 15 (April 5, 2021): e2021219118. http://dx.doi.org/10.1073/pnas.2021219118.
Full textAbstract:
The highest concentration of the world’s lakes are found in Arctic-boreal regions [C. Verpoorter, T. Kutser, D. A. Seekell, L. J. Tranvik, Geophys. Res. Lett. 41, 6396–6402 (2014)], and consequently are undergoing the most rapid warming [J. E. Overland et al., Arctic Report Card (2018)]. However, the ecological response of Arctic-boreal lakes to warming remains highly uncertain. Historical trends in lake color from remote sensing observations can provide insights into changing lake ecology, yet have not been examined at the pan-Arctic scale. Here, we analyze time series of 30-m Landsat growing season composites to quantify trends in lake greenness for >4 × 105 waterbodies in boreal and Arctic western North America. We find lake greenness declined overall by 15% from the first to the last decade of analysis within the 6.3 × 106-km2 study region but with significant spatial variability. Greening declines were more likely to be found in areas also undergoing increases in air temperature and precipitation. These findings support the hypothesis that warming has increased connectivity between lakes and the land surface [A. Bring et al., J. Geophys. Res. Biogeosciences 121, 621–649 (2016)], with implications for lake carbon cycling and energy budgets. Our study provides spatially explicit information linking climate to pan-Arctic lake color changes, a finding that will help target future ecological monitoring in remote yet rapidly changing regions.
3
Bergmann, Martin A., and Harold E. Welch. "Spring Meltwater Mixing in Small Arctic Lakes." Canadian Journal of Fisheries and Aquatic Sciences 42, no. 11 (November 1, 1985): 1789–98. http://dx.doi.org/10.1139/f85-224.
Full textAbstract:
Meltwater mixing in small arctic lakes at Saqvaqjuac (63°68′N, 90°40′W) was studied in 1980 and 1981 to evaluate the applicability of theoretical lake water renewal times to the modeling of ice-covered lakes. Two 370-GBq tritium additions were made to 7.09-ha P&N Lake. One was mixed with the unfrozen water at the time of maximum lake-ice thickness (May 1980) and the other was mixed with the lake immediately after freezing (October 1980). Dye experiments were also performed at four lakes to define the spatial and temporal distribution of the inflow and icemelt layers. Results from the tritiated water and dye addition experiments, as well as conductance and temperature profiles, showed that during ice-on, the cold low-density meltwater floated in a thin layer 0–100 cm beneath the ice, extended over the entire subice-surface area, and left the lake without mixing with the heavier subice water. These results imply that (1) lake models incorporating a lake flushing rate term need to be reevaluated to accommodate the lack of meltwater mixing beneath spring ice and (2) more attention should be given to the early spring meltwater chemistry and its distribution within the upper lake strata.
4
Robinson, Alexis L., Sarah S. Ariano, and Laura C. Brown. "The Influence of Snow and Ice Albedo towards Improved Lake Ice Simulations." Hydrology 8, no. 1 (January 16, 2021): 11. http://dx.doi.org/10.3390/hydrology8010011.
Full textAbstract:
Lake ice models are a vital tool for studying the response of ice-covered lakes to changing climates throughout the world. The Canadian Lake Ice Model (CLIMo) is a one-dimensional freshwater ice cover model that simulates Arctic and sub-Arctic lake ice cover well. Modelling ice cover in temperate regions has presented challenges due to the differences in ice composition between northern and temperate region lake ice. This study presents a comparison of measured and modelled ice regimes, with a focus on refining CLIMo for temperate regions. The study sites include two temperate region lakes (MacDonald Lake and Clear Lake, Central Ontario) and two High Arctic lakes (Resolute Lake and Small Lake, Nunavut) where climate and ice cover information have been recorded over three seasons. The ice cover simulations were validated with a combination of time lapse imagery, field measurements of snow depth, snow density, ice thickness and albedo data, and historical ice records from the Canadian Ice Database (for Resolute Lake). Simulations of High Arctic lake ice cover show good agreement with previous studies for ice-on and ice-off dates (MAE 6 to 8 days). Unadjusted simulations for the temperate region lakes show good ice-on timing, but an under-representation of ice thickness, and earlier complete ice-off timing (~3 to 5 weeks). Field measurements were used to adjust the albedo values used in CLIMo, which resulted in improvements to both simulated ice thickness (~3 cm MAE compared to manual measurements), and ice-off timing, within 0 to 7 days (2 days MAE) of observations. These findings suggest regionally specific measurements of albedo can improve the accuracy of lake ice simulations, which further our knowledge of the response of temperate and High Arctic lake ice regimes to climate conditions.
5
Swanson, Heidi K., Karen A. Kidd, John A. Babaluk, Rick J. Wastle, Panseok P. Yang, Norman M. Halden, and James D. Reist. "Anadromy in Arctic populations of lake trout (Salvelinus namaycush): otolith microchemistry, stable isotopes, and comparisons with Arctic char (Salvelinus alpinus)." Canadian Journal of Fisheries and Aquatic Sciences 67, no. 5 (May 2010): 842–53. http://dx.doi.org/10.1139/f10-022.
Full textAbstract:
In the family Salmonidae, lake trout ( Salvelinus namaycush ) are considered the least tolerant of salt water. There are, however, sporadic reports of lake trout in coastal, brackish habitats in the Canadian Arctic. Otolith microchemistry analyses conducted on lake trout and Arctic char ( Salvelinus alpinus ) from four Arctic lakes in the West Kitikmeot region of Nunavut, Canada, revealed that 37 of 135 (27%) lake trout made annual marine migrations. Anadromous lake trout were in significantly better condition (K = 1.17) and had significantly higher C:N ratios (3.71) than resident lake trout (K = 1.05 and C:N = 3.34). Anadromous lake trout also had significantly higher δ15N (mean = 16.4‰), δ13C (mean = –22.3‰), and δ34S (mean = 13.43‰) isotope ratios than resident lake trout (means = 12.84‰, –26.21‰, and 1.93‰ for δ15N, δ13C, and δ34S, respectively); results were similar for Arctic char and agree with results from previous studies. Mean age of first migration for lake trout was 13 years, which was significantly older than that for Arctic char (5 years). This could be a reflection of size-dependent salinity tolerance in lake trout, but further research is required. These are the first detailed scientific data documenting anadromy in lake trout.
6
Merrick, Glenn W., Anne E. Hershey, and Michael E. McDonald. "Lake Trout (Salvelinus namaycush) Control of Snail Density and Size Distribution in an Arctic Lake." Canadian Journal of Fisheries and Aquatic Sciences 48, no. 3 (March 1, 1991): 498–502. http://dx.doi.org/10.1139/f91-064.
Full textAbstract:
In arctic Alaskan lakes the density and size distribution of the snail Lymnaea elodes appear to be greatly affected by the presence or absence of lake trout (Salvelinus namaycush). Snail densities were much lower and size distributions depressed in lakes where trout were present. During the summer of 1986, lake trout were introduced into an arctic lake to test the effects of their predation on the dominant snail Lymnaea elodes. During July and early August, snail densities in the experimental lake remained stable in the deepwater areas of the lake, but increased significantly in the deepwater areas of an adjacent, troutless control lake, probably due to snail migration from the lake periphery in the absence of predation pressure. These experimental results suggest that the observed pattern of snail distribution and size in lakes containing trout is due to Sake trout predation.
7
Hove, Patrick Van, Claude Belzile, John AE Gibson, and Warwick F. Vincent. "Coupled landscape-lake evolution in High Arctic Canada." Canadian Journal of Earth Sciences 43, no. 5 (May 1, 2006): 533–46. http://dx.doi.org/10.1139/e06-003.
Full textAbstract:
We profiled five ice-covered lakes and two ice-covered fiords of Ellesmere Island at the northern limit of High Arctic Canada to examine their environmental characteristics, and to evaluate the long-term limnological consequences of changes in their surrounding landscape through time (landscape evolution). All of the ecosystems showed strong patterns of thermal, chemical, and biological stratification with subsurface temperature maxima from 0.75 to 12.15 °C; conductivities up to 98.1 mS cm1 (twice that of seawater) in some bottom waters; pronounced gradients in nitrogen, phosphorus, pH, dissolved inorganic and organic carbon, manganese, iron, and oxygen; and stratified photo synthetic communities. These ecosystems form an inferred chronosequence that reflects different steps of landscape evolution including marine embayments open to the sea, inlets blocked by thick sea ice (Disraeli Fiord, Taconite Inlet), perennially ice-capped, saline lakes isolated from the sea by isostatic uplift (Lakes A, C1, C2), and isolated lakes that lose their ice cover in summer. The latter are subject to entrainment of saline water into their upper water column by wind-induced mixing (Lake Romulus; Lake A in 2000), or complete flushing of their basins by dilute snowmelt (Lake C3 and Char Lake, which lies 650 km to the south of the Ellesmere lakes region). This chronosequence illustrates how changes in geomorphology and other landscape properties may influence the limnology of coastal, high-latitude lakes, and it provides a framework to explore the potential impacts of climate change.
8
Stolpmann, Lydia, Caroline Coch, Anne Morgenstern, Julia Boike, Michael Fritz, Ulrike Herzschuh, Kathleen Stoof-Leichsenring, et al. "First pan-Arctic assessment of dissolved organic carbon in lakes of the permafrost region." Biogeosciences 18, no. 12 (June 30, 2021): 3917–36. http://dx.doi.org/10.5194/bg-18-3917-2021.
Full textAbstract:
Abstract. Lakes in permafrost regions are dynamic landscape components and play an important role for climate change feedbacks. Lake processes such as mineralization and flocculation of dissolved organic carbon (DOC), one of the main carbon fractions in lakes, contribute to the greenhouse effect and are part of the global carbon cycle. These processes are in the focus of climate research, but studies so far are limited to specific study regions. In our synthesis, we analyzed 2167 water samples from 1833 lakes across the Arctic in permafrost regions of Alaska, Canada, Greenland, and Siberia to provide first pan-Arctic insights for linkages between DOC concentrations and the environment. Using published data and unpublished datasets from the author team, we report regional DOC differences linked to latitude, permafrost zones, ecoregions, geology, near-surface soil organic carbon contents, and ground ice classification of each lake region. The lake DOC concentrations in our dataset range from 0 to 1130 mg L−1 (10.8 mg L−1 median DOC concentration). Regarding the permafrost regions of our synthesis, we found median lake DOC concentrations of 12.4 mg L−1 (Siberia), 12.3 mg L−1 (Alaska), 10.3 mg L−1 (Greenland), and 4.5 mg L−1 (Canada). Our synthesis shows a significant relationship between lake DOC concentration and lake ecoregion. We found higher lake DOC concentrations at boreal permafrost sites compared to tundra sites. We found significantly higher DOC concentrations in lakes in regions with ice-rich syngenetic permafrost deposits (yedoma) compared to non-yedoma lakes and a weak but significant relationship between soil organic carbon content and lake DOC concentration as well as between ground ice content and lake DOC. Our pan-Arctic dataset shows that the DOC concentration of a lake depends on its environmental properties, especially on permafrost extent and ecoregion, as well as vegetation, which is the most important driver of lake DOC in this study. This new dataset will be fundamental to quantify a pan-Arctic lake DOC pool for estimations of the impact of lake DOC on the global carbon cycle and climate change.
9
Gajewski, Konrad. "Modern and Holocene Pollen Assemblages from Some Small Arctic Lakes on Somerset Island, NWT, Canada." Quaternary Research 44, no. 2 (September 1995): 228–36. http://dx.doi.org/10.1006/qres.1995.1067.
Full textAbstract:
AbstractModern pollen samples from 15 lakes along a north-south transect on western Somerset Island, NWT, Canada, show a decrease in pollen concentrations from the high arctic to the mid-arctic zone, but there are few differences in the pollen percentages between these sites. Long-distance transport accounts for up to 50% of the pollen in these lake sediments. Cores from two lakes show few changes in the percentages of important pollen types, except for an initial period, before 6000 yr B.P., of increased Salix. The pollen concentration of lake RS36 from the mid-arctic is twice that of lake RS29 from the high arctic, and at both sites the concentrations decreased during the past 6000 yr B.P. This suggests a climatic deterioration during the past 6000 yr which has caused a decrease in the abundance of plants on the landscape.
10
Liu, Chong, Huabing Huang, Fengming Hui, Ziqian Zhang, and Xiao Cheng. "Fine-Resolution Mapping of Pan-Arctic Lake Ice-Off Phenology Based on Dense Sentinel-2 Time Series Data." Remote Sensing 13, no. 14 (July 13, 2021): 2742. http://dx.doi.org/10.3390/rs13142742.
Full textAbstract:
The timing of lake ice-off regulates biotic and abiotic processes in Arctic ecosystems. Due to the coarse spatial and temporal resolution of available satellite data, previous studies mainly focused on lake-scale investigations of melting/freezing, hindering the detection of subtle patterns within heterogeneous landscapes. To fill this knowledge gap, we developed a new approach for fine-resolution mapping of Pan-Arctic lake ice-off phenology. Using the Scene Classification Layer data derived from dense Sentinel-2 time series images, we estimated the pixel-by-pixel ice break-up end date information by seeking the transition time point when the pixel is completely free of ice. Applying this approach on the Google Earth Engine platform, we mapped the spatial distribution of the break-up end date for 45,532 lakes across the entire Arctic (except for Greenland) for the year 2019. The evaluation results suggested that our estimations matched well with both in situ measurements and an existing lake ice phenology product. Based on the generated map, we estimated that the average break-up end time of Pan-Arctic lakes is 172 ± 13.4 (measured in day of year) for the year 2019. The mapped lake ice-off phenology exhibits a latitudinal gradient, with a linear slope of 1.02 days per degree from 55°N onward. We also demonstrated the importance of lake and landscape characteristics in affecting spring lake ice melting. The proposed approach offers new possibilities for monitoring the seasonal Arctic lake ice freeze–thaw cycle, benefiting the ongoing efforts of combating and adapting to climate change.
11
Walker, J., and M. McGraw. "Tapped lakes as sediment traps in an Arctic delta." Proceedings of the International Association of Hydrological Sciences 367 (March 3, 2015): 407–12. http://dx.doi.org/10.5194/piahs-367-407-2015.
Full textAbstract:
Abstract. Lakes within the Colville River delta in northern Alaska, USA, vary in size from small ponds created by ice-wedge growth to thaw lakes that are as much as three kilometres long and ten metres deep. As the river migrates, lake edges are breached and the lakes are drained. Such lake tapping is aided by permafrost thaw and ice wedge melt and, in the case of the larger lakes, by wave action within them. Once a lake is tapped, it drains rapidly creating a deep scour hole at its entrance and from then on it is subject to the varying stages and discharge of the river. During flooding, when the river is transporting its largest amount of sediment, the tapped lakes become settling basins and rapidly fill. The Colville River delta has lakes in all stages from freshly breached to those that are now being destroyed by channel migration.
12
Doenz, Carmela J., Andrin K. Krähenbühl, Jonas Walker, Ole Seehausen, and Jakob Brodersen. "Ecological opportunity shapes a large Arctic charr species radiation." Proceedings of the Royal Society B: Biological Sciences 286, no. 1913 (October 23, 2019): 20191992. http://dx.doi.org/10.1098/rspb.2019.1992.
Full textAbstract:
Ecological opportunity is considered a crucial factor for adaptive radiation. Here, we combine genetic, morphological and ecological data to assess species and ecomorphological diversity of Artic charr in six lakes of a catchment in southernmost Greenland, where only charr and stickleback occur. Because the diversity of habitats and resources increases with lake size, we predict a positive association between lake size and the extent of ecomorphological diversity. The largest lake of the catchment harbours the largest Arctic charr assemblage known today. It consists of six genetically differentiated species belonging to five ecomorphs (anadromous, littoral benthic, profundal dwarf, planktivorous, piscivorous), of which the latter comprises two ecomorphologically extremely similar species. Lakes of intermediate size contain two ecomorphologically and genetically distinct species. Small lakes harbour one genetically homogeneous, yet sometimes ecomorphologically variable population. Supporting our prediction, lake size is positively correlated with the extent of ecomorphological specialization towards profundal, pelagic and piscivorous lifestyle. Furthermore, assemblage-wide morphospace increases sharply when more than one genetic cluster is present. Our data suggest that ecological opportunity and speciation jointly determine phenotypic expansion in this charr radiation.
13
Wolfe, Alexander P., and Bianca B. Perren. "Chrysophyte microfossils record marked responses to recent environmental changes in high- and mid-arctic lakes." Canadian Journal of Botany 79, no. 6 (June 1, 2001): 747–52. http://dx.doi.org/10.1139/b01-044.
Full textAbstract:
Rapid stratigraphic changes are recorded in recent assemblages of subfossil Chrysophyceae from the sediments of two highly contrasted arctic lakes, one situated in the polar desert of west-central Ellesmere Island, and the other on eastern Baffin Island in the mid-Arctic climatic zone. In Sawtooth Lake on the Fosheim Peninsula, concentrations of chrysophycean stomatocysts increase dramatically in sediments deposited since AD 1920. Only trace abundances of stomatocysts are encountered in older sediments. In Kekerturnak Lake, on the north coast of Cumberland Peninsula, scales of Mallomonas spp., previously absent from the sediment record, appear suddenly in the upper 5.5 cm of sediment and subsequently become ubiquitous in the top 1.0 cm. These results corroborate diatom stratigraphic data from other sites in the Canadian Arctic Archipelago, together suggesting that unprecedented ecological changes are presently occurring across this vast region. In all likelihood, these abrupt algal community shifts reflect the response of arctic lake ecosystems to well-documented climate warming since the Little Ice Age, with the implications that recent rates of environmental change are unprecedented in the context of the Holocene.Key words: Paleolimnology, arctic lakes, Chrysophyceae, stomatocysts, Mallomonas.
14
Burn, C. R. "Tundra lakes and permafrost, Richards Island, western Arctic coast, Canada." Canadian Journal of Earth Sciences 39, no. 8 (August 1, 2002): 1281–98. http://dx.doi.org/10.1139/e02-035.
Full textAbstract:
Lakes, of average size 33 ha, occupy a quarter of the surface area of Richards Island, Northwest Territories. Most of the lakes have a central pool deeper than the thickness of winter ice, and many have prominent, shallow, littoral terraces. The relatively warm lake bottoms cause considerable disturbance to the surrounding continuous permafrost. Water and lake-bottom temperatures, the configuration of permafrost, and active-layer thickness were measured at a tundra lake between 1992 and 1997. The lake is oval, 1.6 km long, 800 m wide, and as deep as 13 m. Sandy terraces, covered by less than 1 m of water, extend over 100 m from the shore. The terraces are underlain by permafrost, which terminates almost vertically at their edge. The annual mean temperature measured at lake bottom in the central pool ranged between 1.5°C and 4.8°C, depending on depth, and between 0.2°C and 5°C on the terraces, due to differences in snow cover and proximity to the central pool. In consequence, the temperature of permafrost at 7 m depth in the terraces also varied, from 2°C near shore to 5°C in mid-terrace. The active layer in the terraces was uniformly 1.4 m deep. Geothermal modelling of talik configuration indicates that there is no permafrost beneath the central pool of the lake. The modelling indicates that, under equilibrium conditions, about one quarter of the lakes on Richards Island have taliks that penetrate permafrost, and at least 1015% of the island is underlain by talik. Short-term climatic changes predicted for the region imply a small increase in summer lake-water temperature and an extension of the open-water season, accompanied by thicker snow cover in winter. Following such changes, with longer freeze-up and warmer terrace temperatures in winter, permafrost may not be sustainable in the lake terraces.
15
Simpson, Claire E., Christopher D. Arp, Yongwei Sheng, Mark L. Carroll, Benjamin M. Jones, and Laurence C. Smith. "Landsat-derived bathymetry of lakes on the Arctic Coastal Plain of northern Alaska." Earth System Science Data 13, no. 3 (March 19, 2021): 1135–50. http://dx.doi.org/10.5194/essd-13-1135-2021.
Full textAbstract:
Abstract. The Pleistocene sand sea on the Arctic Coastal Plain (ACP) of northern Alaska is underlain by an ancient sand dune field, a geological feature that affects regional lake characteristics. Many of these lakes, which cover approximately 20 % of the Pleistocene sand sea, are relatively deep (up to 25 m). In addition to the natural importance of ACP sand sea lakes for water storage, energy balance, and ecological habitat, the need for winter water for industrial development and exploration activities makes lakes in this region a valuable resource. However, ACP sand sea lakes have received little prior study. Here, we collect in situ bathymetric data to test 12 model variants for predicting sand sea lake depth based on analysis of Landsat-8 Operational Land Imager (OLI) images. Lake depth gradients were measured at 17 lakes in midsummer 2017 using a Humminbird 798ci HD SI Combo automatic sonar system. The field-measured data points were compared to red–green–blue (RGB) bands of a Landsat-8 OLI image acquired on 8 August 2016 to select and calibrate the most accurate spectral-depth model for each study lake and map bathymetry. Exponential functions using a simple band ratio (with bands selected based on lake turbidity and bed substrate) yielded the most successful model variants. For each lake, the most accurate model explained 81.8 % of the variation in depth, on average. Modeled lake bathymetries were integrated with remotely sensed lake surface area to quantify lake water storage volumes, which ranged from 1.056×10-3 to 57.416×10-3 km3. Due to variations in depth maxima, substrate, and turbidity between lakes, a regional model is currently infeasible, rendering necessary the acquisition of additional in situ data with which to develop a regional model solution. Estimating lake water volumes using remote sensing will facilitate better management of expanding development activities and serve as a baseline by which to evaluate future responses to ongoing and rapid climate change in the Arctic. All sonar depth data and modeled lake bathymetry rasters can be freely accessed at https://doi.org/10.18739/A2SN01440 (Simpson and Arp, 2018) and https://doi.org/10.18739/A2HT2GC6G (Simpson, 2019), respectively.
16
Stevenson, Mark A., Suzanne McGowan, Emma J. Pearson, George E. A. Swann, Melanie J. Leng, Vivienne J. Jones, Joseph J. Bailey, Xianyu Huang, and Erika Whiteford. "Anthropocene climate warming enhances autochthonous carbon cycling in an upland Arctic lake, Disko Island, West Greenland." Biogeosciences 18, no. 8 (April 19, 2021): 2465–85. http://dx.doi.org/10.5194/bg-18-2465-2021.
Full textAbstract:
Abstract. The Arctic is rapidly changing, disrupting biogeochemical cycles and the processing, delivery and sedimentation of carbon (C), in linked terrestrial–aquatic systems. In this investigation, we coupled a hydrogeomorphic assessment of catchment soils, sediments and plants with a recent lake sediment sequence to understand the source and quality of organic carbon present in three Arctic upland lake catchments on Disko Island, located just south of the low–high Arctic transition zone. This varied permafrost landscape has exposed soils with less vegetation cover at higher altitudes, and lakes received varying amounts of glacial meltwater inputs. We provide improved isotope and biomarker source identifications for palaeolimnological studies in high-latitude regions, where terrestrial vegetation is at or close to its northerly and altitudinal range limit. The poorly developed catchment soils lead to lake waters with low dissolved organic carbon (DOC) concentrations (≤1.5 mg L−1). Sedimentary carbon/nitrogen (C/N) ratios, the C isotope composition of organic matter (δ13Corg) and biomarker ratios (n-alkanes, n-alkanols, n-alkanoic acids and sterols) showed that sedimentary organic matter (OM) in these lakes is mostly derived from aquatic sources (algae and macrophytes). We used a 210Pb-dated sediment core to determine how carbon cycling in a lake–catchment system (Disko 2) had changed over recent centuries. Recent warming since the end of the Little Ice Age (LIA∼1860 CE), which accelerated after ca. 1950, led to melt of glacier ice and permafrost, releasing nutrients and DOC to the lake and stimulating pronounced aquatic algal production, as shown by a >10-fold increase in β-carotene, indicative of a major regime shift. We also demonstrate that recent increases in catchment terrestrial vegetation cover contributed to the autochthonous response. Our findings highlight that in Arctic lakes with sparsely developed catchment vegetation and soils, recent Anthropocene warming results in pronounced changes to in-lake C processing and the deposition of more reactive, predominately autochthonous C, when compared with extensively vegetated low-Arctic systems.
17
Mi, Y., J. van Huissteden, and A. J. Dolman. "Modelled present and future thaw lake area expansion/contraction trends throughout the continuous permafrost zone." Cryosphere Discussions 8, no. 4 (July 10, 2014): 3603–27. http://dx.doi.org/10.5194/tcd-8-3603-2014.
Full textAbstract:
Abstract. Thaw lakes and drained lake basins are a dominant feature of Arctic lowlands. Thaw lakes are a source of the greenhouse gas methane (CH4), which is produced under anaerobic conditions, while drained lake basins are carbon sinks due to sedimentation. Besides feedbacks on climate, the development of thaw lakes due to the melt-out of ground ice and subsequent ground subsidence, can have significant impacts on the regional morphology, hydrology, geophysics and biogehemistry. Permafrost degradation as a result of climate warming, which is proceeding considerably faster in high latitude regions than the global average, could lead to either an increases in lake area due to lake expansion, or decrease due to lake drainage. However, which process will dominate is elusive. Therefore understanding thaw lake dynamics and quantifying the feedbacks related to thaw lake expansion and contraction are urgent questions to solve. We apply a stochastic model, THAWLAKE, on four representative Arctic sites, to reproduce recent lake dynamics (1963–2012) and predict for the future changes under various anticipated climate scenarios. The model simulations of current thaw lake cycles and expansion rates are comparable with data. Future lake expansions are limited by lake drainage. We suggest further improvements in the area of enhancing the hydrology component, and operation on larger scales to gauge the impacts on lacustrine morphology and greenhouse gas emissions.
18
Brugam, Richard B., Eric C. Grimm, and Nancy M. Eyster-Smith. "Holocene Environmental Changes in Lily Lake, Minnesota Inferred from Fossil Diatom and Pollen Assemblages." Quaternary Research 30, no. 1 (July 1988): 53–66. http://dx.doi.org/10.1016/0033-5894(88)90087-7.
Full textAbstract:
A postglacial core was taken from Lily Lake, a soft-water lake, located on carbonate-poor till in eastern Minnesota. Pollen analysis allowed the reconstruction of watershed vegetation change. Diatom assemblages from the core were compared with 255 surface sediment assemblages from Minnesota, Maine, Labrador, and the Canadian arctic. Late-glacial assemblages were similar to Canadian arctic lakes. During the mid-postglacial period of warmer and drier climate, fossil diatom assemblages at Lily Lake were similar to those in the surface sediment of modern eutrophic hardwater lakes in Central Minnesota. The shift to hardwater diatom assemblages coincided with a shift to prairie species in fossil pollen assemblages at about 8000 yr B.P. At about 3400 year B.P. the fossil diatom assemblage that characterized presettlement times was established.
19
Johnson, Lionel. "Long-term Experiments on the Stability of Two Fish Populations in Previously Unexploited Arctic Lakes." Canadian Journal of Fisheries and Aquatic Sciences 51, no. 1 (January 1, 1994): 209–25. http://dx.doi.org/10.1139/f94-023.
Full textAbstract:
Previous research indicated that fish populations in arctic lakes maintain a constant size distribution and abundance in the face of the environmental variability experienced over their recent history. Such stability was tested over 15 seasons in Little Nauyuk and Gavia lakes (Northwest Territories) which contained previously undisturbed populations of Arctic char (Salvelinus alpinus). Initially, the length–frequency distribution of Arctic char in Little Nauyuk Lake was bell shaped, and in Gavia Lake, it could be described by a negative logarithmic expression. Initial sampling of Gavia Lake removed the largest fish, allowing a well-defined mode to develop (cf. Little Nauyuk Lake). In both lakes the modal value remained constant throughout the exploitation phase. When fishing ceased the populations returned to their original state without evident oscillation. The stable state of the dominant population is considered to be one of "least dissipation". It is hypothesized that ecosystem structure depends on countervailing forces, one tending to decelerate energy flow through the ecosystem and the second tending to accelerate it. For ecosystems to exist, the tendency to decelerate energy flow must dominate system behaviour over ecological time. An ecosystem is regarded as a hemeorhetic system, stability seeking through the stabilization of energy flows.
20
Michelutti, Neal, Marianne S. V. Douglas, Alexander P. Wolfe, and John P. Smol. "Heightened sensitivity of a poorly buffered high arctic lake to late-Holocene climatic change." Quaternary Research 65, no. 3 (May 2006): 421–30. http://dx.doi.org/10.1016/j.yqres.2006.02.001.
Full textAbstract:
AbstractA diatom-based paleolimnological investigation was conducted on late Holocene sediments from a poorly buffered lake, informally named “Rock Basin Lake”, on Ellesmere Island, Arctic Canada. The fossil diatom record is unlike any other obtained thus far from high arctic regions, exhibiting dynamic assemblage shifts over the entire ∼3300 yr sedimentary record. Multiple proxies (i.e., diatoms, pH reconstructions, biogenic silica, C/N ratios, total organic carbon) appear to sensitively track rapid limnological changes, which are associated with distinct climate intervals as inferred from other regional proxy records. The highly responsive nature of the diatom assemblages in Rock Basin Lake, relative to those recorded from nearby alkaline sites, appears to be related to this lake's limited ability to buffer changes in pH. The dynamic species responses suggest that the diatoms in Rock Basin Lake are faithfully tracking climatic changes, and that low-alkalinity lakes may provide the most sensitive diatom-based paleolimnological records from high arctic regions.
21
Paytan, Adina, Alanna L. Lecher, Natasha Dimova, Katy J. Sparrow, Fenix Garcia-Tigreros Kodovska, Joseph Murray, Slawomir Tulaczyk, and John D. Kessler. "Methane transport from the active layer to lakes in the Arctic using Toolik Lake, Alaska, as a case study." Proceedings of the National Academy of Sciences 112, no. 12 (March 9, 2015): 3636–40. http://dx.doi.org/10.1073/pnas.1417392112.
Full textAbstract:
Methane emissions in the Arctic are important, and may be contributing to global warming. While methane emission rates from Arctic lakes are well documented, methods are needed to quantify the relative contribution of active layer groundwater to the overall lake methane budget. Here we report measurements of natural tracers of soil/groundwater, radon, and radium, along with methane concentration in Toolik Lake, Alaska, to evaluate the role active layer water plays as an exogenous source for lake methane. Average concentrations of methane, radium, and radon were all elevated in the active layer compared with lake water (1.6 × 104 nM, 61.6 dpm⋅m−3, and 4.5 × 105 dpm⋅m−3 compared with 1.3 × 102 nM, 5.7 dpm⋅m−3, and 4.4 × 103 dpm⋅m−3, respectively). Methane transport from the active layer to Toolik Lake based on the geochemical tracer radon (up to 2.9 g⋅m−2⋅y−1) can account for a large fraction of methane emissions from this lake. Strong but spatially and temporally variable correlations between radon activity and methane concentrations (r2 > 0.69) in lake water suggest that the parameters that control methane discharge from the active layer also vary. Warming in the Arctic may expand the active layer and increase the discharge, thereby increasing the methane flux to lakes and from lakes to the atmosphere, exacerbating global warming. More work is needed to quantify and elucidate the processes that control methane fluxes from the active layer to predict how this flux might change in the future and to evaluate the regional and global contribution of active layer water associated methane inputs.
22
Arbour, J. H., D. C. Hardie, and J. A. Hutchings. "Morphometric and genetic analyses of two sympatric morphs of Arctic char (Salvelinus alpinus) in the Canadian High Arctic." Canadian Journal of Zoology 89, no. 1 (January 2011): 19–30. http://dx.doi.org/10.1139/z10-100.
Full textAbstract:
Multivariate morphometric analyses were used to examine variation in head, body, and fin shape between two sympatric morphotypes of Arctic char ( Salvelinus alpinus (L., 1758)) from Lake Hazen, Ellesmere Island, Nunavut, Canada. Population structure of the Lake Hazen Arctic char was examined using five microsatellite loci. The “small” morph was found to have a larger (primarily deeper) head, larger and more elongate fins, and a deeper lateral profile than the “large” morph. The morphs also differed in allometric growth patterns. The large and small morphs do not appear to represent genetically distinct populations. The head morphology of the Lake Hazen small and large morphs exhibited similarities to benthic and pelagic morphs (respectively) from other lakes. We hypothesize that the large morph may be adapted to high-efficiency swimming and that the small morph may be adapted to low-efficiency, high-acceleration swimming. Such functional trade-offs are not uncommon among fish specializing in dispersed or mobile prey (fish and plankton) and benthic prey, respectively. The lack of apparent genetic differentiation between the morphs may suggest that the morphological differences result, to some extent, from phenotypic plasticity. Based on these results and previous analyses, it seems reasonable to conclude that Lake Hazen Arctic char represent a resource polymorphism.
23
Abbott, Mark B., and Thomas W. Stafford. "Radiocarbon Geochemistry of Modern and Ancient Arctic Lake Systems, Baffin Island, Canada." Quaternary Research 45, no. 3 (May 1996): 300–311. http://dx.doi.org/10.1006/qres.1996.0031.
Full textAbstract:
AbstractThe accuracy of Arctic lake chronologies has been assessed by measuring the 14C activities of modern carbon sources and applying these isotopic mass balances to dating fossil lake materials. Small (<1 km2) shallow (<25 m) Arctic lakes with watersheds <12 km2have soil and peat stratigraphic sections with14C activities ranging from 98 to 51% Modern. The14C activity of particulate organic carbon, dissolved organic carbon, and dissolved inorganic carbon from lake and stream waters ranges from 121 to 95% Modern. The sediment–water interface of the studied lakes shows consistent14C ages of ∼100014C yr, although the14C activity of living aquatic vegetation is 115% Modern. Radiocarbon measurements of components of the lacustrine carbon pool imply that the ∼100014C yr age of the sediment–water interface results from deposition of14C-depleted organic matter derived from the watershed.
24
McDonald, Michael E., Anne E. Hershey, and Michael C. Miller. "Global warming impacts on lake trout in arctic lakes." Limnology and Oceanography 41, no. 5 (July 1996): 1102–8. http://dx.doi.org/10.4319/lo.1996.41.5.1102.
Full text
25
Febria, Catherine M., Lance FW Lesack, Jolie AL Gareis, and Max L. Bothwell. "Patterns of hydrogen peroxide among lakes of the Mackenzie Delta, western Canadian Arctic." Canadian Journal of Fisheries and Aquatic Sciences 63, no. 9 (September 1, 2006): 2107–18. http://dx.doi.org/10.1139/f06-106.
Full textAbstract:
Dissolved organic carbon (DOC) in Mackenzie Delta lakes varies in composition and concentration, ranging from low concentrations and high colour in frequently flooded lakes to high concentrations in clear lakes that are infrequently flooded. DOC is a precursor to the photochemical production of hydrogen peroxide (H2O2) in lake waters. Here we assessed the patterns of H2O2 using three approaches: (i) H2O2 levels were tracked in 40 lakes during the open water season from the Arctic summer solstice (24 h sunlight) to late summer; (ii) diurnal dynamics of in situ H2O2 were tracked in a pair of lakes with contrasting DOC regimes (coloured vs. noncoloured DOC); and (iii) buildup of H2O2 was tracked in experimental microcosms of lake water exposed to manipulated UV levels. H2O2 levels were highest at the solstice and in intermittently flooded lakes. During 24 h daylight, lakes with contrasting DOC regimes showed cumulative build up of H2O2 during multiple cloudless days. Cumulatively, H2O2 was highest in the Delta lake with a higher DOC concentration and low in colour. H2O2 buildup in lake water shielded from UVB exposure was not significantly lower from microcosms under full sunlight. UVA was the most important in coloured DOC photobleaching and H2O2 production.
26
Kelly, Seán, Tadhg N. Moore, Elvira de Eyto, Mary Dillane, Chloé Goulon, Jean Guillard, Emilien Lasne, et al. "Warming winters threaten peripheral Arctic charr populations of Europe." Climatic Change 163, no. 1 (October 17, 2020): 599–618. http://dx.doi.org/10.1007/s10584-020-02887-z.
Full textAbstract:
AbstractAs the global climate warms, the fate of lacustrine fish is of huge concern, especially given their sensitivity as ectotherms to changes in water temperature. The Arctic charr (Salvelinus alpinus L.) is a salmonid with a Holarctic distribution, with peripheral populations persisting at temperate latitudes, where it is found only in sufficiently cold, deep lakes. Thus, warmer temperatures in these habitats particularly during early life stages could have catastrophic consequences on population dynamics. Here, we combined lake temperature observations, a 1-D hydrodynamic model, and a multi-decadal climate reanalysis to show coherence in warming winter water temperatures in four European charr lakes near the southernmost limit of the species’ distribution. Current maximum and mean winter temperatures are on average ~ 1 °C warmer compared to early the 1980s, and temperatures of 8.5 °C, adverse for high charr egg survival, have frequently been exceeded in recent winters. Simulations of winter lake temperatures toward century-end showed that these warming trends will continue, with further increases of 3–4 °C projected. An additional 324 total accumulated degree-days during winter is projected on average across lakes, which could impair egg quality and viability. We suggest that the perpetuating winter warming trends shown here will imperil the future status of these lakes as charr refugia and generally do not augur well for the fate of coldwater-adapted lake fish in a warming climate.
27
Joynt III, Ernest H., and Alexander P. Wolfe. "Paleoenvironmental inference models from sediment diatom assemblages in Baffin Island lakes (Nunavut, Canada) and reconstruction of summer water temperature." Canadian Journal of Fisheries and Aquatic Sciences 58, no. 6 (June 1, 2001): 1222–43. http://dx.doi.org/10.1139/f01-071.
Full textAbstract:
Diatoms from the surface sediments of 61 lakes on Baffin Island, Nunavut, were identified, enumerated, and interpreted quantitatively. The samples span a latitudinal transect from 62 to 74°N, reflecting climatic and vegetational gradients that range from low Arctic to transitional mid-Arctic to high Arctic. While the sampled lakes encompass both predominantly maritime and continental climatic regimes, sites have been deliberately restricted to basins in Precambrian crystalline terrain to mitigate the edaphic consequences of alkaline sedimentary bedrock. Canonical correspondence analysis, using forward selection and Monte Carlo permutation tests, identified pH, conductivity, summer lake water temperature, and mean annual air temperature as significant environmental controls over diatom assemblages. Using weighted-averaging regression and calibration, predictive models for these parameters have been developed. When applied to down-core assemblages, the summer lake water temperature model provides realistic reconstructions when compared with other paleoenvironmental records. Over the past 5000 years, the amplitude of reconstructed summer lake water temperature is on the order of 4.0°C, expressed primarily as progressive Neoglacial cooling culminating in the Little Ice Age. Diatom-inferred summer water temperatures have increased by 2.0°C in the past 150 years, again in agreement with independent paleoclimatic reconstructions.
28
Wilson, Chris C., and Paul D. N. Hebert. "Natural Hybridization between Arctic Char (Salvelinus alpinus) and Lake Trout (S. namaycush) in the Canadian Arctic." Canadian Journal of Fisheries and Aquatic Sciences 50, no. 12 (December 1, 1993): 2652–58. http://dx.doi.org/10.1139/f93-288.
Full textAbstract:
Natural interspecific hybrids between lake trout (Salvelinus namaycush) and Arctic char (S. alpinus) ranged in frequency from 1.8 to 6.8% in four of eleven lakes containing both species on the northern Melville Peninsula, N.W.T., and were also detected at several other sites across the Canadian Arctic. Hybrids were heterozygous for each of seven diagnostic allozyme loci between S. alpinus and S. namaycush, and were morphologically intermediate between the parental species. Restriction endonuclease analysis of mitochondrial DNA revealed that all but one of the hybrids had S. namaycush as their maternal parent. Resampling of two lakes where hybrids were detected revealed low levels of bidirectional nuclear introgression between the two species and limited transfer of S. namaycush mtDNA into S. alpinus.
29
Sturm, Matthew, and Glen E. Liston. "The snow cover on lakes of the Arctic Coastal Plain of Alaska, U.S.A." Journal of Glaciology 49, no. 166 (2003): 370–80. http://dx.doi.org/10.3189/172756503781830539.
Full textAbstract:
AbstractShallow lakes cover >25% of Alaska’s Arctic Coastal Plain. These remain frozen and snow-covered from October to June. The lake snow is thinner, denser, harder and has less water equivalent than snow on the surrounding tundra. Itcontains less depth hoar than land snow, yet paradoxically is subject to stronger temperature gradients. It also has fewer layers and these have been more strongly affected by wind. Dunes and drifts are better developedon lakes; they have wavelengths of 5–20 m, compared to <5 m on land. Because of these differences, lake snow has roughly half the thermal insulating capacity of land snow. The winter mass balance on lakes is also different because (1) some snow falls into the water before the lakes freeze, (2) some snow accumulates in drifts surrounding the lakes, and (3) prevailing winds lead to increased erosion and thinner snow on the eastern lake sides. Physical models that extrapolate land snow over lakes without appropriate adjustments for depth, density, distribution and thermal properties will under-predict ice thickness and winter heat losses.
30
Sand-Jensen, Kaj, Tenna Riis, Stiig Markager, and Warwick F. Vincent. "Slow growth and decomposition of mosses in Arctic lakes." Canadian Journal of Fisheries and Aquatic Sciences 56, no. 3 (March 1, 1999): 388–93. http://dx.doi.org/10.1139/f98-184.
Full textAbstract:
Aquatic mosses are often the exclusive form of macrophytic vegetation in Arctic lakes. Despite the cold nutrient-poor water and the short ice-free summer, the mosses form dense stands on the lake bottom down to great depths. The environmental conditions suggest that moss growth and decomposition are extremely slow, but logistical and methodological difficulties have so far precluded direct measurements of the processes. Here, we use temporal changes in the size and density of leaves along the axis of moss shoots collected from different depths in Char Lake and North Lake in the Canadian High Arctic to reconstruct the annual growth and decomposition of the mosses during the past 10-17 years. Our results show low but remarkably constant annual elongation rates (about 10 mm·shoot-1) in the long-lived shoots that carry green leaves for several years and decompose slowly. Cold temperatures and low nutrient supply in combination with the short Arctic growing season can account for the low growth rate, the low decomposition rates, and the unprecedented longevity of these moss communities relative to other submerged macrophytes.
31
Rumyantsev, V. A., A. V. Izmailova, and L. N. Kryukov. "State of Lake Water Resources in the Russian Arctic Zone." Arctic and Antarctic Research 64, no. 1 (March 30, 2018): 84–100. http://dx.doi.org/10.30758/0555-2648-2018-64-1-84-100.
Full textAbstract:
Regions of the Russian Federation classified among Arctic zone estimated to 22% of Russian territory. Arctic is characterized by the richest reserves of natural resources, and its phased, balanced development is the most important strategic task of Russia’s socioeconomic development. Production and household activities of the population of Russia living and working in the far North is associated with difficult climatic and geographical conditions. In this case, the constant cold and consumption of contaminated water can lead to aggravation of various human disease. The Arctic zone of the Russian Federation is characterized by the richness of water resources as rapidly renewable (river runoff and its underground component), and static one to which are assigned the waters of lakes, underground waters, waters (ice) of mountain and polar glaciers. A characteristic feature of water consumption in the Arctic regions is the active use of lake water, which in a number of settlements is the main source of drinking water supply. In this regard, the assessment of the lake’s fund of Arctic zone and its ecological status is extremely topical.According to the assessments, more than 2.5 million water bodies, that is a ~2/3 of all water bodies of the country, are decoded in the Arctic zone of the Russian Federation on satellite images. Mainly, these are small water bodies, only about 975 thousand of them exceed 1 ha. The total area of the water surface of Arctic lakes is ~160 thousand km2 (slightly less than a half of the total water surface of all natural water bodies of the Russian Federation), and the total volume of water enclosed in them is ~760 km3.Even in the middle of the 20th century, the lakes of the Russian Arctic, with rare exceptions, were characterized by the highest quality of their waters, but by now the ecological status of many water bodies has deteriorated significantly. The vulnerability of Arctic lakes to pollution is enhanced both by virtue of the peculiarities of their orometry and by the simplicity of the biological communities of northern ecosystems characterized by a low degree of stability. The poor knowledge of Arctic water bodies does not allow taking the necessary preventive measures for their protection and rational use. In this connection, attention to the expansion of works on the integrated study of limnology of water bodies included in the lake fund of the Arctic zone should be paid.An estimation of water resources of lakes of the Arctic zone of Russia, their ecological status and the questions of etiology of diseases on the territories of the Far North are given in this article. The morbidity of the population of the Arctic regions of Russia today is much higher than the national average. Further development of the territory and the observed warming of the climate will lead to increasing pollution of freshwater resources with toxic substances, pathogenic microorganisms and viruses. This will exacerbate the issue of ensuring environmental safety and meeting the needs of the population in quality drinking water. The situation is further aggravated by the fact that the most affordable technologies for water treatment and wastewater treatment in conditions of low temperatures and high content of humic substances in the initial water cannot ensure the proper level of disinfection. In this regard, one of the topical issues is the creation of innovative technologies for water purification that are more adequate to the conditions of the Arctic zone of Russia.
32
Chertoprud, M. V., S. V. Krylenko, A. I. Lukinych, P. M. Glazov, O. P. Dubovskaya, and E. S. Chertoprud. "Specific Features of the Macrozoobenthic Communities of Small Arctic Lakes in Eurasia." Inland Water Biology 14, no. 4 (July 2021): 401–14. http://dx.doi.org/10.1134/s1995082921030056.
Full textAbstract:
Abstract The taxonomic structure, typology, species richness, and total abundance of bentic and littoral macroinvertebrate communities from small lakes of the Arctic and Subarctic zones are considered on the basis of original data from three northern Palearctic regions (the foot of the Putorana Plateau, Kolguev Island, and Western Svalbard Island). A comparative analysis of the communities of these regions has been carried out. The features of High Arctic insular, Low Arctic, subarctic, and boreal lake communities are discussed using a large volume of literature data. The complex pattern of changes in the total benthos biomass of small lakes has been revealed: it decreases in the subarctic taiga, increases in the hypoarctic tundra, and decreases again in the High Arctic.
33
Pathak, Prasad, and Stephen Whalen. "Using Geospatial Techniques to Analyze Landscape Factors Controlling Ionic Composition of Arctic Lakes, Toolik Lake Region, Alaska." International Journal of Applied Geospatial Research 3, no. 3 (July 2012): 37–57. http://dx.doi.org/10.4018/jagr.2012070103.
Full textAbstract:
The impacts of climate change on landscapes in arctic Alaska are evident in terms of permafrost melting, frequent thermokarst activity, and the occurrence of more broadleaf vegetation. These changes may alter natural biogeochemical cycles of ions along with major nutrients and affect ionic compositions of lakes, as they are connected with the landscapes. However, the nature of the connectivity between lakes and landscapes in this region is not yet explored. The authors propose that geospatial analysis of landscape properties along with observed lake ion concentrations will enable an understanding of the currently existing landscape controls over ion inputs into the lakes. For the watersheds of 41 lakes in the Arctic Foothills region of Alaska, spatial properties of natural vegetation communities expressed in terms of percentage, shape complexity, and patch density metrics were derived using satellite data. Regression analyses were performed for concentration of ions as well as conductivity in lake water where the spatial metrics along with lake physical properties, lake order, and glacial till age categories were used as predicting variables in the regression. Landscape metrics for major land covers i.e., Percentage of Moist Acidic Tundra (MAT) and Moist Non-acidic Tundra (MNT) were the major predicting variables for concentration of several ions.
34
Pearce, David A., Charles S. Cockell, Eva S. Lindström, and Lars J. Tranvik. "First evidence for a bipolar distribution of dominant freshwater lake bacterioplankton." Antarctic Science 19, no. 2 (May 22, 2007): 245–52. http://dx.doi.org/10.1017/s0954102007000326.
Full textAbstract:
AbstractAs a result of the recent application of DNA based technology to the investigation of maritime Antarctic freshwater lakes, patterns have begun to emerge in the bacterioplankton communities that dominate these systems. In this study, the bacterioplankton communities of five Antarctic and five Arctic freshwater lakes were assessed and compared with existing data in the literature, to determine whether emerging patterns in Antarctic lakes also applied to Arctic systems. Such a bipolar comparison is particularly timely, given the current interest in biogeography, the global distribution of microorganisms and the controversy over the global ubiquity hypothesis. In addition, it has recently been discovered that commonly encountered bacterial sequences, often originating from uncultivated bacteria obtained on different continents, form coherent phylogenetic freshwater clusters. In this study we encountered both identical sequences and sequences with a high degree of similarity among the bacterioplankton in lake water from both poles. In addition, Arctic freshwater lakes appeared to be dominated by some of the same groups of bacterioplankton thought to be dominant in Antarctic lakes, the vast majority of which represented uncultivated groups.
35
Brown, L. C., and C. R. Duguay. "The fate of lake ice in the North American Arctic." Cryosphere Discussions 5, no. 4 (July 5, 2011): 1775–834. http://dx.doi.org/10.5194/tcd-5-1775-2011.
Full textAbstract:
Abstract. Lakes comprise a large portion of the surface cover in northern North America forming an important part of the cryosphere. The timing of lake ice phenological events (e.g. break-up/freeze-up) are useful indicators of climate variability and change, which is of particular relevance in environmentally sensitive areas such as the North American Arctic. Further alterations to the present day ice regime could result in major ecosystem changes, such as species shifts and the disappearance of perennial ice cover. Lake ice models are a valuable tool for examining the response of lake ice cover to changing climate conditions. The use of future climate scenario data in these models can provide information on the potential changes in ice phenology, ice thickness and composition. The Canadian Lake Ice Model (CLIMo) was used to simulate lake ice phenology across the North American Arctic from 1961–2100 using climate scenarios produced by the Canadian Regional Climate Model (CRCM). Results from the 1961–1990 time period were validated using 15 locations across the Canadian Arctic, with both in situ ice cover observations from the Canadian Ice Database as well as additional ice cover simulations using nearby weather station data. Projected changes to the ice cover using the 30 yr mean data between 1961–1990 and 2041–2070 suggest a shift towards shorter ice cover durations by an average of just over 3 weeks, with a 25 cm average reduction of the total ice thickness – varying based on location, lake depth and snow cover amounts.
36
Bergmann, Martin A., and Harold E. Welch. "Nitrogen Fixation by Epilithic Periphyton in Small Arctic Lakes in Response to Experimental Nitrogen and Phosphorus Fertilization." Canadian Journal of Fisheries and Aquatic Sciences 47, no. 8 (August 1, 1990): 1545–50. http://dx.doi.org/10.1139/f90-174.
Full textAbstract:
Epilithic periphyton played a moderate role in the nitrogen budget of four small arctic lakes located at Saqvaqjuac, N.W.T. The acetylene reduction technique used to estimate nitrogen fixation indicated that periphyton in 0–2 m water depth were capable of fixing up to 0.86 mg N∙m−2∙h−1 during the period of active nitrogen fixation from July to September 1981. Far Lake was fertilized with Phosphorus for 3 yr and had a higher rate of fixation than did a P- and N-fertilized lake or a control lake, in agreement with similar studies on temperate and subarctic lakes. A numerical model based on incoming light was used to perdict the amount of nitrogen fixed in each study lake throughout the season. The calculated contribution of periphyton to the overall N budget for 1981 was 5% for the P- and N-fertilized lake, 16% for the control lake and 28% for the P-only fertilized lake.
37
Matveev, A. N., V. P. Samusenok, A. L. Yuriev, A. I. Vokin, I. V. Samusenok, and S. S. Alekseyev. "Biology of Fishes of Lake Frolikha (Northern Baikal Region, East Siberia)." Bulletin of Irkutsk State University. Series Biology. Ecology 32 (2020): 50–82. http://dx.doi.org/10.26516/2073-3372.2020.32.50.
Full textAbstract:
The fish fauna of Lake Frolikha comprises 12 species confirmed by our recent studies: roach Rutilus rutilus (L.), minnow Phoxinus phonixus (L.), stone loach Barbatula toni (Dyb.), spine loach Cobitis melanoleuca Nichols, pike Esox lucius L. lenok Brachymystax lenok (Pallas), Arctic charr Salvelinus alpinus (L.), Baikal black grayling Thymallus baicalensis (Dyb.), burbot Lota lota (L.), sand sculpin Leocottus kesslerii (Dyb.), stone sculpin Paracottus knerii (Dyb.) and perch Perca fluviatilis L. Biological peculiarities of these fishes are determined by unique geographical position and limnic characteristics of Lake Frolikha. Being a typical glacial lake it is located at rather low altitude a.s.l. and is adjacent to the unparalleled ecosystem of Lake Baikal. An underdeveloped shallow coastal zone with sparse aquatic vegetation, which is characteristic of glacial lakes, determines some biological traits of Lake Frolikha cyprinids. As compared with other mountain lakes of Baikal Rift Zone (BRZ), roach and minnow have lower rates of linear and weight growth as well as unusual population sex ratios. Male to female ratio in roach is 2:1 and in minnow it is 1:1 whereas in other lakes it reaches 1:4 and 1:10 respectively. The presence of native Baikal species in Lake Frolikha provided abundant food for piscivores: sand sculpins are the dominant food item of lenok, Arctic charr and perch. Lenok and perch demonstrate prominent linear and weight growth rate in the lake. In other lakes of BRZ with less abundant prey fish species Arctic charr typically diverge into several trophic forms, but in Lake Frolikha they established a monomorphic mostly piscivorous population. Charr from Lake Frolikha are relatively small and short-lived representatives of the large form of Transbaikalian charr. Their unique feature is river spawning, which is not observed in any other charr population within BRZ. Due to special protection regime of the territory, which minimizes catch losses, several fish species maintain natural unaffected structure of their populations evidenced by the abundance of old fish. The population of lenok is represented by 19 age groups, the population of roach – by 15 groups and that of burbot – by 12 groups. Alternatively, populations of small-sized prey species such as minnow and sand sculpin, which are heavily influenced by numerous predators include fewer age groups than in other mountain lakes of BRZ.
38
Grosswald, Mikhail G., Terence J. Hughes, and Norman P. Lasca. "Oriented lake-and-ridge assemblages of the Arctic coastal plains: glacial landforms modified by thermokarst and solifluction." Polar Record 35, no. 194 (July 1999): 215–30. http://dx.doi.org/10.1017/s0032247400015503.
Full textAbstract:
AbstractOriented assemblages of parallel ridges and elongated lakes are widespread on the coastal lowlands of northeast Eurasia and Arctic North America, in particular, in Alaska, Arctic Canada, and northeast Siberia. So far, only the oriented lakes have been of much scientific interest. They are believed to be formed by thermokarst in perennially frozen ice-rich sediments, while their orientation is accounted for either by impact of modern winds blowing at right angles to long axes of the lakes (when it concerns individual lakes), or by the influence of underlying bedrock structures (in the case of longitudinal and transverse alignment of lake clusters).En masseexamination of space images suggests that oriented lake-and-ridge assemblages, not the oriented lakes alone, occur in the Arctic. Hence any theory about their formation should account for the origin and orientation of the assemblages as a whole. The existing hypotheses appear inadequate for this end, so this paper proposes that the assemblages were initially created by glacial activity, that is, by ice sheets that drumlinized and tectonized their beds, as well as by sub- and proglacial meltwater, and then they were modified by thermokarst, solifluction, and aeolian processes. This assumption opens up an avenue by which all known features of oriented landforms in the Arctic can be explained. The paper suggests that the oriented landforms in Siberia and Alaska are largely signatures of a marine Arctic ice sheet that transgressed from the north, while the Baffin Island and Mackenzie Delta forms were created by the respective sectors of the Laurentide ice sheet. The oriented features discussed belong to the last Late Glacial through the Early Holocene.
39
Campana, Steven E., John M. Casselman, and Cynthia M. Jones. "Bomb radiocarbon chronologies in the Arctic, with implications for the age validation of lake trout (Salvelinus namaycush) and other Arctic species." Canadian Journal of Fisheries and Aquatic Sciences 65, no. 4 (April 1, 2008): 733–43. http://dx.doi.org/10.1139/f08-012.
Full textAbstract:
Radiocarbon generated by atmospheric testing of nuclear weapons (bomb radiocarbon) produced a strong signal with an abrupt onset in the 1950s, which serves as a dated marker for tracing oceanic circulation and confirming age in animals forming growth bands. Here, we report the first prebomb and postbomb radiocarbon chronologies for marine and freshwater environments in the Canadian Arctic, extend the radiocarbon chronology for the northwest Atlantic Ocean, and use the onset of the bomb signal to validate our age interpretations of lake trout (Salvelinus namaycush) in Arctic lakes. Both surface and deepwater Arctic chronologies became detectable on or around 1958, similar to the year of onset elsewhere in the world. In contrast, the freshwater Arctic chronology increased sharply in 1957, with a peak value sixfold higher than the adjacent marine environment. The radiocarbon content of the adult otolith core validated our age interpretation criteria for Arctic lake trout to an age of at least 50 years. Otolith growth in such slow-growing fish was so low as to be unresolvable under conventional examination with a dissecting microscope. With these new radiocarbon reference chronologies, age validation of a large number of Arctic organisms should now be possible.
40
Casselman, John M., Cynthia M. Jones, and Steven E. Campana. "Bomb radiocarbon age validation for the long-lived, unexploited Arctic fish species Coregonus clupeaformis." Marine and Freshwater Research 70, no. 12 (2019): 1781. http://dx.doi.org/10.1071/mf18354.
Full textAbstract:
The growth rates of freshwater fish in the Arctic would be expected to be very low, but some previous studies of lake whitefish (Coregonus clupeaformis) have reported relatively rapid growth and longevity estimates of less than 15 years. We used bomb radiocarbon chronologies to validate an ageing method based on otolith sections for lake whitefish in both an unexploited Arctic lake (MacAlpine Lake; longevity 50 years) and a lightly exploited temperate population (Lake Simcoe; longevity 49 years). Our results confirm previous suggestions that other ageing methods can seriously underestimate lake whitefish age after ~5–8 years. A Chapman–Robson estimate of instantaneous natural mortality rate (M) of 0.12 in the unfished Arctic lake was one-quarter of that measured in other Arctic lake whitefish populations, and one-third of that predicted by Pauly’s (1980) growth–temperature equation. The high estimates of M reported in other whitefish studies and by Pauly’s equation are almost certainly due to their being based on (incorrect) scale or surface otolith ages. Radiocarbon dating confirms that any attempt at predicting sustainable production for long-lived freshwater fishes like lake whitefish will need to be based on accurate ages derived from otolith sections.
41
Brown, L. C., and C. R. Duguay. "The fate of lake ice in the North American Arctic." Cryosphere 5, no. 4 (October 20, 2011): 869–92. http://dx.doi.org/10.5194/tc-5-869-2011.
Full textAbstract:
Abstract. Lakes comprise a large portion of the surface cover in northern North America, forming an important part of the cryosphere. The timing of lake ice phenological events (e.g. break-up/freeze-up) is a useful indicator of climate variability and change, which is of particular relevance in environmentally sensitive areas such as the North American Arctic. Further alterations to the present day ice regime could result in major ecosystem changes, such as species shifts and the disappearance of perennial ice cover. The Canadian Lake Ice Model (CLIMo) was used to simulate lake ice phenology across the North American Arctic from 1961–2100 using two climate scenarios produced by the Canadian Regional Climate Model (CRCM). Results from the 1961–1990 time period were validated using 15 locations across the Canadian Arctic, with both in situ ice cover observations from the Canadian Ice Database as well as additional ice cover simulations using nearby weather station data. Projected changes to the ice cover using the 30-year mean data between 1961–1990 and 2041–2070 suggest a shift in break-up and freeze-up dates for most areas ranging from 10–25 days earlier (break-up) and 0–15 days later (freeze-up). The resulting ice cover durations show mainly a 10–25 day reduction for the shallower lakes (3 and 10 m) and 10–30 day reduction for the deeper lakes (30 m). More extreme reductions of up to 60 days (excluding the loss of perennial ice cover) were shown in the coastal regions compared to the interior continental areas. The mean maximum ice thickness was shown to decrease by 10–60 cm with no snow cover and 5–50 cm with snow cover on the ice. Snow ice was also shown to increase through most of the study area with the exception of the Alaskan coastal areas.
42
Vyse, Stuart A., Ulrike Herzschuh, Gregor Pfalz, Lyudmila A. Pestryakova, Bernhard Diekmann, Norbert Nowaczyk, and Boris K. Biskaborn. "Sediment and carbon accumulation in a glacial lake in Chukotka (Arctic Siberia) during the Late Pleistocene and Holocene: combining hydroacoustic profiling and down-core analyses." Biogeosciences 18, no. 16 (August 24, 2021): 4791–816. http://dx.doi.org/10.5194/bg-18-4791-2021.
Full textAbstract:
Abstract. Lakes act as important sinks for inorganic and organic sediment components. However, investigations of sedimentary carbon budgets within glacial lakes are currently absent from Arctic Siberia. The aim of this paper is to provide the first reconstruction of accumulation rates, sediment and carbon budgets from a lacustrine sediment core from Lake Rauchuagytgyn, Chukotka (Arctic Siberia). We combined multiple sediment biogeochemical and sedimentological parameters from a radiocarbon-dated 6.5 m sediment core with lake basin hydroacoustic data to derive sediment stratigraphy, sediment volumes and infill budgets. Our results distinguished three principal sediment and carbon accumulation regimes that could be identified across all measured environmental proxies including early Marine Isotope Stage 2 (MIS2) (ca. 29–23.4 ka cal BP), mid-MIS2–early MIS1 (ca. 23.4–11.69 ka cal BP) and the Holocene (ca. 11.69–present). Estimated organic carbon accumulation rates (OCARs) were higher within Holocene sediments (average 3.53 g OC m−2 a−1) than Pleistocene sediments (average 1.08 g OC m−2 a−1) and are similar to those calculated for boreal lakes from Quebec and Finland and Lake Baikal but significantly lower than Siberian thermokarst lakes and Alberta glacial lakes. Using a bootstrapping approach, we estimated the total organic carbon pool to be 0.26 ± 0.02 Mt and a total sediment pool of 25.7 ± 1.71 Mt within a hydroacoustically derived sediment volume of ca. 32 990 557 m3. The total organic carbon pool is substantially smaller than Alaskan yedoma, thermokarst lake sediments and Alberta glacial lakes but shares similarities with Finnish boreal lakes. Temporal variability in sediment and carbon accumulation dynamics at Lake Rauchuagytgyn is controlled predominantly by palaeoclimate variation that regulates lake ice-cover dynamics and catchment glacial, fluvial and permafrost processes through time. These processes, in turn, affect catchment and within-lake primary productivity as well as catchment soil development. Spatial differences compared to other lake systems at a trans-regional scale likely relate to the high-latitude, mountainous location of Lake Rauchuagytgyn.
43
Evincent, Warwick E., Isabelle Laurion, and Reinhard Pienitz. "Arctic and Antarctic lakes as optical indicators of global change." Annals of Glaciology 27 (1998): 691–96. http://dx.doi.org/10.3189/1998aog27-1-691-696.
Full textAbstract:
Lakes are a major feature of Arctic and Antarctic landscapes and are likely to be sensitive indicators ofclimate change. New bio-optical technologies for in situ measurements (e.g. UV-profiling) and remote sensing (e.g. light detection and ranging) now offer a suite of options for long-term monitoring at these sites. Certain properties of high-latitude lakes are highly responsive to changes in climate forcing and could be targeted within a monitoring strategy based on optical properties; these include lake levels, lake-ice dynamics, phytoplankton biomass and chromophoric dissolved organic matter (CDOM). High-latitude lakes are optically sensitive to changes in CDOM export from their surrounding catchments that could result from climate effects on hydrology and vegetation. Using a new model based on biologically weighted transparency, we show that a 20% change in GDOM concentration (as measured by dissolved organic carbon) can have a much greater effect on UV inhibition of phytoplankton than a similar percentage change in stratospheric ozone. Much of this effect is due to UV-A, because the reduced photodamaging effect per unit energy (i.e. low biological weighting) in this waveband is offset by its higher incident flux at the lake surface relative to UV-B and its deeper penetration into the water column. These transparency calculations also show that small changes in CDOM in polar lakes will have a large effect on underwater light availability for photosynthesis. The spectral absorption and fluorescence properties of CDOM lend themselves to a variety of optical monitoring approaches. Future research on the paleo-optics of GDOM will allow the interpretation of current optical trends in high-latitude lakes relative to the scales of natural variability in the past.
44
Tan, Zeli, Qianlai Zhuang, Daven K. Henze, Christian Frankenberg, Ed Dlugokencky, Colm Sweeney, Alexander J. Turner, Motoki Sasakawa, and Toshinobu Machida. "Inverse modeling of pan-Arctic methane emissions at high spatial resolution: what can we learn from assimilating satellite retrievals and using different process-based wetland and lake biogeochemical models?" Atmospheric Chemistry and Physics 16, no. 19 (October 12, 2016): 12649–66. http://dx.doi.org/10.5194/acp-16-12649-2016.
Full textAbstract:
Abstract. Understanding methane emissions from the Arctic, a fast-warming carbon reservoir, is important for projecting future changes in the global methane cycle. Here we optimized methane emissions from north of 60° N (pan-Arctic) regions using a nested-grid high-resolution inverse model that assimilates both high-precision surface measurements and column-average SCanning Imaging Absorption spectroMeter for Atmospheric CHartogrphY (SCIAMACHY) satellite retrievals of methane mole fraction. For the first time, methane emissions from lakes were integrated into an atmospheric transport and inversion estimate, together with prior wetland emissions estimated with six biogeochemical models. In our estimates, in 2005, global methane emissions were in the range of 496.4–511.5 Tg yr−1, and pan-Arctic methane emissions were in the range of 11.9–28.5 Tg yr−1. Methane emissions from pan-Arctic wetlands and lakes were 5.5–14.2 and 2.4–14.2 Tg yr−1, respectively. Methane emissions from Siberian wetlands and lakes are the largest and also have the largest uncertainty. Our results indicate that the uncertainty introduced by different wetland models could be much larger than the uncertainty of each inversion. We also show that assimilating satellite retrievals can reduce the uncertainty of the nested-grid inversions. The significance of lake emissions cannot be identified across the pan-Arctic by high-resolution inversions, but it is possible to identify high lake emissions from some specific regions. In contrast to global inversions, high-resolution nested-grid inversions perform better in estimating near-surface methane concentrations.
45
Teller, James T. "Lake Agassiz during the Younger Dryas." Quaternary Research 80, no. 3 (November 2013): 361–69. http://dx.doi.org/10.1016/j.yqres.2013.06.011.
Full textAbstract:
Lake Agassiz was ponded on the northward-sloping surface of the Hudson Bay and Arctic Ocean basins, as the Laurentide Ice Sheet retreated. The level of Lake Agassiz abruptly fell ~ 12.9 cal (11 14C) ka BP, exposing the lake floor over a large region for > 1000 yr. The routing of overflow during this (Moorhead low-water) period is uncertain, and there is evidence on the continent and in ocean basins for both an easterly route through the Great Lakes–St. Lawrence to the North Atlantic and for a northwesterly route through the Clearwater–Athabasca–Mackenzie system to the Arctic Ocean. The Moorhead low water phase coincides with the Younger Dryas cooling, and a cause–effect relationship has been proposed by attributing a change in ocean thermohaline circulation to the re-routing of Lake Agassiz freshwaters from the Gulf of Mexico to more northern oceans. Paleoclimatic interpretations from ecosystems in lake sediments in the region, and a simple calculation of the paleohydrological budget of Lake Agassiz, indicate that the climate remained wet and cool throughout the YD in this region, and was not warm nor dry enough to allow evaporative loss to offset the influx of meltwater and precipitation; thus, the Moorhead phase resulted from changes in the outlet that carried overflow.
46
Wilson, Cheryl R., Neal Michelutti, Colin A. Cooke, Jason P. Briner, Alexander P. Wolfe, and John P. Smol. "Arctic lake ontogeny across multiple interglaciations." Quaternary Science Reviews 31 (January 2012): 112–26. http://dx.doi.org/10.1016/j.quascirev.2011.10.018.
Full text
47
LaPerriere, Jacqueline D. "Lake types of central Arctic Alaska." SIL Proceedings, 1922-2010 27, no. 1 (April 2000): 352. http://dx.doi.org/10.1080/03680770.1998.11901251.
Full text
48
Tan, Z., Q. Zhuang, D. K. Henze, C. Frankenberg, E. Dlugokencky, C. Sweeney, and A. J. Turner. "Mapping pan-Arctic methane emissions at high spatial resolution using an adjoint atmospheric transport and inversion method and process-based wetland and lake biogeochemical models." Atmospheric Chemistry and Physics Discussions 15, no. 22 (November 18, 2015): 32469–518. http://dx.doi.org/10.5194/acpd-15-32469-2015.
Full textAbstract:
Abstract. Understanding methane emissions from the Arctic, a fast warming carbon reservoir, is important for projecting changes in the global methane cycle under future climate scenarios. Here we optimize Arctic methane emissions with a nested-grid high-resolution inverse model by assimilating both high-precision surface measurements and column-average SCIAMACHY satellite retrievals of methane mole fraction. For the first time, methane emissions from lakes are integrated into an atmospheric transport and inversion estimate, together with prior wetland emissions estimated by six different biogeochemical models. We find that, the global methane emissions during July 2004–June 2005 ranged from 496.4 to 511.5 Tg yr−1, with wetland methane emissions ranging from 130.0 to 203.3 Tg yr−1. The Arctic methane emissions during July 2004–June 2005 were in the range of 14.6–30.4 Tg yr−1, with wetland and lake emissions ranging from 8.8 to 20.4 Tg yr−1 and from 5.4 to 7.9 Tg yr−1 respectively. Canadian and Siberian lakes contributed most of the estimated lake emissions. Due to insufficient measurements in the region, Arctic methane emissions are less constrained in northern Russia than in Alaska, northern Canada and Scandinavia. Comparison of different inversions indicates that the distribution of global and Arctic methane emissions is sensitive to prior wetland emissions. Evaluation with independent datasets shows that the global and Arctic inversions improve estimates of methane mixing ratios in boundary layer and free troposphere. The high-resolution inversions provide more details about the spatial distribution of methane emissions in the Arctic.
49
Morris, K., M. O. Jeffries, and W. F. Weeks. "Ice processes and growth history on Arctic and sub-Arctic lakes using ERS-1 SAR data." Polar Record 31, no. 177 (April 1995): 115–28. http://dx.doi.org/10.1017/s0032247400013619.
Full textAbstract:
AbstractA survey of ice growth and decay processes on a selection of shallow and deep sub-Arctic and Arctic lakes was conducted using radiometrically calibrated ERS-1 SAR images. Time series of radar backscatter data were compiled for selected sites on the lakes during the period of ice cover (September to June) for the years 1991–92 and 1992–93. A variety of lake-ice processes could be observed, and significant changes in backscatter occurred from the time of initial ice formation in autumn until the onset of the spring thaw. Backscatter also varied according to the location and depth of the lakes. The spatial and temporal changes in backscatter were most constant and predictable at the shallow lakes on the North Slope of Alaska. As a consequence, they represent the most promising sites for long-term monitoring and the detection of changes related to global warming and its effects on the polar regions.
50
Kuhn, Catherine, Aji John, Janneke Hille Ris Lambers, David Butman, and Amanda Tan. "Arctic-Boreal Lake Phenology Shows a Relationship between Earlier Lake Ice-Out and Later Green-Up." Remote Sensing 13, no. 13 (June 29, 2021): 2533. http://dx.doi.org/10.3390/rs13132533.
Full textAbstract:
Satellite remote sensing has transformed our understanding of Earth processes. One component of the Earth system where large uncertainties remain are Arctic and boreal freshwater lakes. With only short periods of open water due to annual ice cover, lake productivity in these regions is extremely sensitive to warming induced changes in ice cover. At the same time, productivity dynamics in these lakes vary enormously, even over short distances, making it difficult to understand these potential changes. A major impediment to an improved understanding of lake dynamics has been sparsely distributed field measurements, in large part due to the complexity and expense of conducting scientific research in remote northern latitudes. This project overcomes that hurdle by using a new set of ‘eyes in the sky’, the Planet Labs CubeSat fleet, to observe 35 lakes across 3 different arctic-boreal ecoregions in western North America. We extract time series of lake reflectance to identify ice-out and green-up across three years (2017–2019). We find that lakes with later ice-out have significantly faster green-ups. Our results also show ice-out varies latitudinally by 38 days from south to north, but only varies across years by ~9 days. In contrast, green-up varied between years by 22 days in addition to showing significant spatial variability. We compare PlanetScope to Sentinel-2 data and independently validate our ice-out estimates, finding an ice-out mean absolute difference (MAD) ~9 days. This study demonstrates the potential of using CubeSat imagery to monitor the timing and magnitude of ice-off and green-up at high spatiotemporal resolution.