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1
Hatef, Hakimeh, Mahmoud Daneshvar Kakhki, Mohammad Reza Kohansal, Mohammad Bannayan, and Naser Shahnoushi Froshani. "Climate vulnerability index fluctuation: a case of Iran." Journal of Water and Climate Change 10, no. 1 (May 3, 2018): 223–35. http://dx.doi.org/10.2166/wcc.2018.044.
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Abstract Climatic fluctuations have severe effects on water and soil resources and economy as a whole. It is hence important to study the fluctuations of climatic parameters in different regions in order to recognize the source and type of parameter that have led to fluctuating climatic parameters. To achieve this goal, the current study attempts to address the following issues: what are the different sources of fluctuations in climate parameters? Do different regions have the same degree of vulnerability and what is the most fluctuating parameter in each region? To answer these questions, the study suggests climate vulnerability index fluctuation. Calculating the index requires data provided by weather stations, so 115 weather stations were divided into 12 climatic zones based on the availability of data. This index considered permanent and frequent temperature, precipitation, storm and aridity shocks. The results indicated that the maximum rank of index has occurred in hot semi-mountainous and very hot desert. Also, temperature fluctuation was the major factor in five regions, whereas wind fluctuation was the major factor in three regions. Generally, the northern and western parts of the country experienced minimum climatic changes. Moving towards southern regions of the country, more climatic changes were observed.
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AMERI, ISMAEL DAWOOD SULAIMAN AL. "Climate Fluctuation in Mesopotamia During the Quaternary Period." Journal of Research on the Lepidoptera 50, no. 4 (December 30, 2019): 262–78. http://dx.doi.org/10.36872/lepi/v50i4/201090.
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Ghozali, Ghozali. "Pengaruh Iklim dan Fluktuasi Harga Bawang Merah dan Bawang Putih terhadap Pendapatan Petani (Studi Kasus pada Petani Sayur di Pacet Mojokerto)." JEBDEER: Journal of Entrepreneurship, Business Development and Economic Educations Research 1, no. 1 (December 11, 2017): 35–44. http://dx.doi.org/10.32616/jbr.v1i1.53.
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Many people are involved in the vegetable trade business, the majority of farmers in Pacet plunge in planting shallot and garlic, Along with the number of traders, the majority of demand more and more, and when the harvest price is very low and make the farmers lose, and when the season Rain arrives, farmers in the Pacet region many do not plant, so the scarcity of shallot and garlic price is rising. The purpose of this paper is the influence of climate and price fluctuations simultaneously affect the farmer's income, climate influence and price fluctuations affect partially on the market, the variables that predominantly affect the income level of farmers.
The results showed that climate and fluctuation influence simultaneously to farmer's earnings that is X1 (Climate) and X2 (Price fluctuation) obtained F value count bigger than F table value (4,391> 3,35). Climate and price fluctuation have partial effect to farmer's income t value (3,45> 2,055) with significance level less than 0,05 0.008 and t variable X2 (price fluctuation) bigger than t table (8.561> 2.055) with significance level below 0.05 ie 0.002. And the most dominant variable influencing farmer's income is price fluctuation from SPSS result shows between variable X1 (climate) and variable X2 (price fluctuation) obtained In variable X1, pearson correlation 0,381 <pearson correlation X2 0,081 This means that variable X2 price fluctuations are more influential on farmers' income.
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Bestion, Elvire, Bart Haegeman, Soraya Alvarez Codesal, Alexandre Garreau, Michèle Huet, Samuel Barton, and José M. Montoya. "Phytoplankton biodiversity is more important for ecosystem functioning in highly variable thermal environments." Proceedings of the National Academy of Sciences 118, no. 35 (August 26, 2021): e2019591118. http://dx.doi.org/10.1073/pnas.2019591118.
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The 21st century has seen an acceleration of anthropogenic climate change and biodiversity loss, with both stressors deemed to affect ecosystem functioning. However, we know little about the interactive effects of both stressors and in particular about the interaction of increased climatic variability and biodiversity loss on ecosystem functioning. This should be remedied because larger climatic variability is one of the main features of climate change. Here, we demonstrated that temperature fluctuations led to changes in the importance of biodiversity for ecosystem functioning. We used microcosm communities of different phytoplankton species richness and exposed them to a constant, mild, and severe temperature-fluctuating environment. Wider temperature fluctuations led to steeper biodiversity–ecosystem functioning slopes, meaning that species loss had a stronger negative effect on ecosystem functioning in more fluctuating environments. For severe temperature fluctuations, the slope increased through time due to a decrease of the productivity of species-poor communities over time. We developed a theoretical competition model to better understand our experimental results and showed that larger differences in thermal tolerances across species led to steeper biodiversity–ecosystem functioning slopes. Species-rich communities maintained their ecosystem functioning with increased fluctuation as they contained species able to resist the thermally fluctuating environments, while this was on average not the case in species-poor communities. Our results highlight the importance of biodiversity for maintaining ecosystem functions and services in the context of increased climatic variability under climate change.
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Hua, Yingmin. "Long-Term Variations of Earth's Orbital Geometry and its Effect on the Climate System." Symposium - International Astronomical Union 156 (1993): 336. http://dx.doi.org/10.1017/s0074180900173450.
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Chinese Loess data over the past 2.4 million years are good proxy records for understanding past climate. Maximum entropy spectrum of magnectic susceptibility data at the locality of Luochuan, which is in Shaanxi province of China, have shown periodic fluctuations of about 21 kyr, 41 kyr, 100 kyr and 400 kyr. These periodic fluctuations are related to the long-term variations of earth's orbital elements of the obliquity, the climatic precession and the eccentricity respectively. The data series was separated into two parts to examine the variations of these fluctuations. The first part is from present to 1.1 Myr B.P.(i.e. million years before present), the second part is from 1.1 Myr B.P. to 2.2 Myr B.P. The periodic fluctuation of 93.4 kyr has the maximum amplitude in the first part of the data series, while the periodic fluctuation of 413 kyr has the maximum amplitude in the second part. The fluctuation about the 400 kyr was found in both parts of the data series.
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Schnabel, Julius, and Seppo Valkealahti. "Energy Storage Requirements for PV Power Ramp Rate Control in Northern Europe." International Journal of Photoenergy 2016 (2016): 1–11. http://dx.doi.org/10.1155/2016/2863479.
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Photovoltaic (PV) generators suffer from fluctuating output power due to the highly fluctuating primary energy source. With significant PV penetration, these fluctuations can lead to power system instability and power quality problems. The use of energy storage systems as fluctuation compensators has been proposed as means to mitigate these problems. In this paper, the behavior of PV power fluctuations in Northern European climatic conditions and requirements for sizing the energy storage systems to compensate them have been investigated and compared to similar studies done in Southern European climate. These investigations have been performed through simulations that utilize measurements from the Tampere University of Technology solar PV power station research plant in Finland. An enhanced energy storage charging control strategy has been developed and tested. Energy storage capacity, power, and cycling requirements have been derived for different PV generator sizes and power ramp rate requirements. The developed control strategy leads to lesser performance requirements for the energy storage systems compared to the methods presented earlier. Further, some differences on the operation of PV generators in Northern and Southern European climates have been detected.
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Boulton, G. S., N. Hulton, and M. Vautravers. "Ice-sheet models as tools for palaeoclimatic analysis: the example of the European ice sheet through the last glacial cycle." Annals of Glaciology 21 (1995): 103–10. http://dx.doi.org/10.1017/s0260305500015676.
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A numerical model is used to simulate ice-sheet behaviour in Europe through the last glacial cycle. It is used in two modes: a forward mode, in which the model is driven by a proxy palaeoclimate record and the output compared with a geological reconstruction of ice-sheet fluctuation; and an inverse mode, in which we determine the climate function that would be required to simulate geologically reconstructed ice-sheet fluctuations. From these simulations it is concluded that extra-glacial climates may be poor predictors of ice-sheet surface climates, and that climatic transitions during the glacial period may have been much more rapid and the intensity of warming during the early Holocene much greater than hitherto supposed. Stronger climate forcing is required to drive ice-sheet expansion when sliding occurs at the bed compared with a non-sliding bed. Sliding ice sheets grow more slowly and decay more rapidly than non-sliding ice sheets with the same climate forcing.
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Zhao, Chao. "The Climate Fluctuation of the 8.2 ka BP Cooling Event and the Transition into Neolithic Lifeways in North China." Quaternary 3, no. 3 (August 4, 2020): 23. http://dx.doi.org/10.3390/quat3030023.
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Early Neolithic lifeways in North China, which are marked by a low-level food production economy, population aggregation, and sedentism, thrived just after the period of a climatic cooling event at 8.2 ka. Instead of simply regarding this climate fluctuation as a cause for the significant socio-economic transition, this paper attempts to explore the interplay between people’s choices of coping strategies with climate change as a perspective to learn how people respond to this climate fluctuation and how such responses generated the interlocked socio-economic transitions. This analysis indicates that pre-existing changes in human adaptive behaviors prior to the cooling events were sufficient to enable people in certain areas to apply the intensification of food procurement in circumscribed territories as a strategy to cope with the climate fluctuations of the 8.2 ka BP cooling event. The application of such a coping strategy facilitated the economic and sociopolitical transition into Neolithic lifeways and led to the flourishing development of Neolithic cultures after 8 ka BP in North China.
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Tanti Novianti, Silvia Sari Busnita, Rina Oktaviani,. "How far climate change affects the Indonesian paddy production and rice price volatility?" International Journal of Agricultural Sciences 1, no. 1 (September 1, 2017): 1. http://dx.doi.org/10.25077/ijasc.1.1.1-11.2017.
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Food security issue after 2008 global-crisis is something relate with the climate change phenomenon which had worsened on the last few decades. The impact of global climate change can be seen from the fluctuation of main crops production yield in tropical countries. This has affected the food price fluctuations particularly on the grain price, both international and domestic markets. The rice-commodity, known for its thin market characteristics, is now also experiencing the fluctuation of production, its productivity and also the rice price. Considering the importance of rice as the main staple food in Indonesia, the purpose of this research is to identify the Indonesia’s rice price fluctuation (volatility) and to investigate how far climate change affects the Indonesian paddy production and rice price volatility. By applying monthly time-series data from 2007 to 2014, this research used ARCH-GARCH methods to find out the rice price volatility and VECM (Vector Error Correction Model) to investigate the impact of climate change phenomenon on the Indonesian paddy production, as well as rice price volatility both in the short-run and long-run. The result is important for the stakeholders and government in preventing the risk and uncertainty condition of paddy production and rice price fluctuation caused by climate change
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Chu, Peter C. "First Passage Time Analysis on Climate Indices." Journal of Atmospheric and Oceanic Technology 25, no. 2 (February 1, 2008): 258–70. http://dx.doi.org/10.1175/2007jtecha991.1.
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Abstract Climate variability is simply represented by teleconnection patterns such as the Arctic Oscillation (AO), Antarctic Oscillation (AAO), North Atlantic Oscillation (NAO), Pacific–North American pattern (PNA), and Southern Oscillation (SO) with associated indices. Two approaches can be used to predict the indices: forward and backward methods. The forward method is commonly used to predict the index fluctuation ρ at time t with a given temporal increment τ. Using this method, it was found that the index (such as for NAO) has the Brownian fluctuations. On the basis of the first passage time (FPT) concept, the backward method is introduced in this study to predict the typical time span (τ) needed to generate a fluctuation in the index of a given increment ρ. After the five monthly indices (AO, AAO, NAO, PNA, and SO) run through the past history, the FPT density functions are obtained. FPT presents a new way to detect the temporal variability of the climate indices. The basic features for the index prediction are also discussed.
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Shi, Y., Y. Wang, Y. Ma, W. Ma, C. Liang, D. F. B. Flynn, B. Schmid, J. Fang, and J. S. He. "Field-based observations of regional-scale, temporal variation in net primary production in Tibetan alpine grasslands." Biogeosciences 11, no. 7 (April 9, 2014): 2003–16. http://dx.doi.org/10.5194/bg-11-2003-2014.
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Abstract. Net primary production (NPP) is a fundamental process of natural ecosystems. Temporal variation of NPP not only reflects how communities respond to environmental fluctuations, but it also has important implications for regional carbon assessment. Unfortunately, studies based on field measurements to directly address this issue in the extreme environment of alpine grasslands are rare. In this study, we measured aboveground NPP (ANPP) and species richness in 40 sites across the Tibetan alpine grasslands from 2006 to 2009 to investigate the regional pattern of temporal variation in ANPP and to quantify the effects of climate fluctuation and biodiversity on this variation. The results showed that, during the 4-year period, the average ANPP varied 1.5-fold, from 83.9 to 125.7 g m−2, with a mean coefficient of variation of temporal variation of 36.6% across the 40 sites. Compared with other studies, alpine grasslands are not more sensitive to climate fluctuations than other grassland types. Aboveground NPP exhibited synchronous temporal variation and consistent spatial patterns over the 4-year period due to the regionally similar climatic fluctuations caused by monsoon-dominated plateau climate. Surprisingly, rainfall fluctuation had a more profound effect on the ANPP dynamics than temperature variation, which suggests that production in the Tibetan alpine grasslands is primarily driven by precipitation. Therefore, ANPP in the Tibetan alpine grasslands are mainly constrained by water availability. Finally, we found a reduction in interannual variation (i.e., CV) in ANPP with increasing species richness of plant communities, suggesting that diversity can stabilize community production in high-altitude grasslands.
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Seiffert, Rita, and Jin-Song von Storch. "A Stochastic Analysis of the Impact of Small-Scale Fluctuations on the Tropospheric Temperature Response to CO2 Doubling." Journal of Climate 23, no. 9 (May 1, 2010): 2307–19. http://dx.doi.org/10.1175/2009jcli3043.1.
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Abstract The climate response to increased CO2 concentration is generally studied using climate models that have finite spatial and temporal resolutions. Different parameterizations of the effect of unresolved processes can result in different representations of small-scale fluctuations in the climate model. The representation of small-scale fluctuations can, on the other hand, affect the modeled climate response. In this study the mechanisms by which enhanced small-scale fluctuations alter the climate response to CO2 doubling are investigated. Climate experiments with preindustrial and doubled CO2 concentrations obtained from a comprehensive climate model [ECHAM5/Max Planck Institute Ocean Model (MPI-OM)] are analyzed both with and without enhanced small-scale fluctuations. By applying a stochastic model to the experimental results, two different mechanisms are found. First, the small-scale fluctuations can change the statistical behavior of the global mean temperature as measured by its statistical damping. The statistical damping acts as a restoring force that determines, according to the fluctuation–dissipation theory, the amplitude of the climate response to a change in external forcing (here, CO2 doubling). Second, the small-scale fluctuations can affect processes that occur only in response to the CO2 increase, thereby altering the change of the effective forcing on the global mean temperature.
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Rahman, Mohammad Lutfar, Md Shahjahan, and Nesar Ahmed. "Tilapia Farming in Bangladesh: Adaptation to Climate Change." Sustainability 13, no. 14 (July 8, 2021): 7657. http://dx.doi.org/10.3390/su13147657.
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In Bangladesh, aquaculture is critically important in terms of providing food and nutrition, sustainable livelihoods, income, and export earnings. Nevertheless, aquaculture in Bangladesh has faced recent concerns due to climate change. Aquaculture is vulnerable to a combination of climatic factors, such as global warming, rainfall variation, flood, drought, temperature fluctuation, and salinity change. Considering the vulnerability of fish production to the impacts of climate change, tilapia farming is one of the possible strategies for adaptation to climate change. The positive culture attributes of tilapia are their tolerance to low water levels and poor water quality with rainfall variation, temperature fluctuation, and salinity change. In fact, tilapia farming is possible in a wide range of water environments, including freshwater, brackish water, and saltwater conditions. We suggest that appropriate tilapia culture strategies with institutional support and collaboration with key stakeholders are needed for adaptation to environmental change.
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Cooper, Fenwick C., and Peter H. Haynes. "Climate Sensitivity via a Nonparametric Fluctuation–Dissipation Theorem." Journal of the Atmospheric Sciences 68, no. 5 (May 1, 2011): 937–53. http://dx.doi.org/10.1175/2010jas3633.1.
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Abstract The fluctuation–dissipation theorem (FDT) has been suggested as a method of calculating the response of the climate system to a small change in an external parameter. The simplest form of the FDT assumes that the probability density function of the unforced system is Gaussian and most applications of the FDT have made a quasi-Gaussian assumption. However, whether or not the climate system is close to Gaussian remains open to debate, and non-Gaussianity may limit the usefulness of predictions of quasi-Gaussian forms of the FDT. Here we describe an implementation of the full non-Gaussian form of the FDT. The principle of the quasi-Gaussian FDT is retained in that the response to forcing is predicted using only information available from observations of the unforced system, but in the non-Gaussian case this information must be used to estimate aspects of the probability density function of the unforced system. Since this estimate is implemented using the methods of nonparametric statistics, the new form is referred to herein as a “nonparametric FDT.” Application is demonstrated to a sequence of simple models including a stochastic version of the three-component Lorenz model. The authors show that the nonparametric FDT gives accurate predictions in cases where the quasi-Gaussian FDT fails. Practical application of the nonparametric FDT may require optimization of the method set out here for higher-dimensional systems.
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Nicolis, C., J. P. Boon, and G. Nicolis. "Fluctuation-dissipation theorem and intrinsic stochasticity of climate." Il Nuovo Cimento C 8, no. 3 (May 1985): 223–42. http://dx.doi.org/10.1007/bf02574709.
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Chun, Xi, Mei Jie Zhang, and Mei Ping Liu. "The Coincident Relationships between the Qehan Lake Area Fluctuation and the Climate Change in the Nearly 40 Years." Applied Mechanics and Materials 137 (October 2011): 286–90. http://dx.doi.org/10.4028/www.scientific.net/amm.137.286.
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The objective of this study is to analyse the climate changing patterns chronologically for exposing the coincident relationships between the lake area fluctuation and the climate change in Qehan lake of Abaga county of Inner Mongolia. The results show that there’s highly interrelation between the changes of the lake area and the climatic factors here, the annual average temperature and annual evaporation are negatively interrelate to the lake area fluctuation, and the annual precipitation interrelate to it is positive. The lake area has descended about 75 km2 during the nearly past 40 years. There were about two considerable lake expansions in 1973, 1998 through the generally lake area descending process.
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Utete, Beaven, Tamuka Nhiwatiwa, Blessing Kavhu, Samuel Kusangaya, Nyashadzashe Viriri, Accurate W. Mbauya, and Joshua Tsamba. "Assessment of water levels and the effects of climatic factors and catchment dynamics in a shallow subtropical reservoir, Manjirenji Dam, Zimbabwe." Journal of Water and Climate Change 10, no. 3 (March 2, 2018): 580–90. http://dx.doi.org/10.2166/wcc.2018.134.
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Abstract Natural water level fluctuations have associated effects on water quality and resident aquatic communities, although their impacts are magnified if the dams have other non-seasonal designated multiple uses. Research demonstrates that excessive water level fluctuations impair ecosystem functioning, ultimately leading to shifts between clear-water and turbid states in shallow lakes. However, these data lack for Manjirenji Dam in Zimbabwe, thus hampering efforts towards effective freshwater resources management in the shallow reservoir. This study analyzed water levels and their fluctuations, and assessed the effects of climatic factors and catchment dynamics using a combination of historical and remote sensed data for the shallow Manjirenji Dam in Zimbabwe. Time series and multiple regression analysis were used to determine water level trends, and the influence of catchment and climatic components in Manjirenji Dam. Lake levels have increased since construction, though their non-significant seasonal variation in the Manjirenji Dam reflects the overlapping effects of catchment and climatic variables. Despite the inferred high stability and resilience, the high fluctuation widths expose the dam to hydrodynamic and climate shocks which have major ecological and conservation implications. A climate change based integrated water resources management approach is necessary for sustainable water resources utilisation in the Manjirenji Dam.
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Chiang, Camilo, Daniel Bånkestad, and Günter Hoch. "Reaching Natural Growth: The Significance of Light and Temperature Fluctuations in Plant Performance in Indoor Growth Facilities." Plants 9, no. 10 (October 5, 2020): 1312. http://dx.doi.org/10.3390/plants9101312.
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Recommendations for near-natural plant growth under indoor conditions have been described without considering environmental fluctuations, which might have important consequences for researchers and plant producers when comparing results from indoor facilities with natural ecosystems or production. Previous authors proposed that differences in temperature, light quantity, and the lack of their variation are sources of deviations between indoor and outdoor experiments. Here, we investigated the effect of fluctuating light, temperature, and humidity in an indoor environment on plant performance. Seven plant species from different functional plant types were grown outdoors during summer and spring. The same species were then grown in indoor growth chambers under different scenarios of climate complexity in terms of fluctuations of temperature, air humidity, and light: (1) fixed night and day conditions, (2) daily sinusoidal changes, and (3) variable conditions tracking the climate records from the field trials. In each scenario, the average of the environmental variables was the same as in the respective field trial. Productivity-, gas exchange-, and leaf pigment-traits were measured in all plants at the end of the experiments. The plant trait responses were highly dependent on species and treatment, but general trends were observed. The variable condition yielded lower biomass compared to the fixed and sinusoidal conditions, together with a higher specific leaf area and increased chlorophyll concentrations. A principal component analysis (PCA) across all plant traits in response to climatic conditions suggested that at least a sinusoidal fluctuation is recommended for a more natural-like plant performance in indoor growth facilities. However, prevailing significant differences for several traits between field- and indoor-grown plants even under variable climates indicate that additional factors other than those controllable in standard phytotrons (e.g., wind speed and direction, leaf and soil temperature) can still significantly bias plant performance in indoor facilities.
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Boulton, G. S., N. Hulton, and M. Vautravers. "Ice-sheet models as tools for palaeoclimatic analysis: the example of the European ice sheet through the last glacial cycle." Annals of Glaciology 21 (1995): 103–10. http://dx.doi.org/10.3189/s0260305500015676.
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A numerical model is used to simulate ice-sheet behaviour in Europe through the last glacial cycle. It is used in two modes: a forward mode, in which the model is driven by a proxy palaeoclimate record and the output compared with a geological reconstruction of ice-sheet fluctuation; and an inverse mode, in which we determine the climate function that would be required to simulate geologically reconstructed ice-sheet fluctuations.From these simulations it is concluded that extra-glacial climates may be poor predictors of ice-sheet surface climates, and that climatic transitions during the glacial period may have been much more rapid and the intensity of warming during the early Holocene much greater than hitherto supposed. Stronger climate forcing is required to drive ice-sheet expansion when sliding occurs at the bed compared with a non-sliding bed. Sliding ice sheets grow more slowly and decay more rapidly than non-sliding ice sheets with the same climate forcing.
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Sanogo, Karamoko, Birhanu Zemadim Birhanu, Souleymane Sanogo, Abdulkadir Aishetu, and Abdramane Ba. "Spatiotemporal Response of Vegetation to Rainfall and Air Temperature Fluctuations in the Sahel: Case Study in the Forest Reserve of Fina, Mali." Sustainability 13, no. 11 (June 1, 2021): 6250. http://dx.doi.org/10.3390/su13116250.
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Forests constitute a key component of the Earth system but the sustainability of the forest reserves in the semi-arid zone is a real concern since its vegetation is very sensitive to the climate fluctuation. The understanding of the mechanisms for the vegetation–climate interaction is poorly studied in the context of African Sahel. In this study, the characteristics of the vegetation response to the fluctuations of precipitation and temperature is determined for the forest reserve of Fina. Rainfall estimates, air temperature and NDVI were re-gridded to a same spatial resolution and standardized with respect to their respective long-term mean. Lag-correlations analysis was used to estimate lag times between changes of climate variables and vegetation response at both seasonal and interannual bases. Results show increasing tendency of NDVI started from the 1990s coinciding the recovery of the rainfall from the 1980s drought, and the obtained correlation (r = 0.66) is statistically significant (p value < 0.01). The strongest responses of vegetation to rainfall and temperature fluctuations were found after 30 and 15 days, respectively. Moreover, at a shorter time lag (e.g., 15 days), more pronounced vegetation responses to both rainfall and temperature were found in agriculturally dominated land while at a longer time lag (e.g., 30 days), a stronger response was observed in Bare-dominated land. The vegetation response to the climate fluctuation is modulated by the land-use/cover dynamics.
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N. Collins, David. "Climatic Variables and Mass Balance Of Alpine Glaciers During A Period Of Climate Fluctuation." Annals of Glaciology 14 (1990): 333. http://dx.doi.org/10.1017/s0260305500008934.
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Parameterisation of relationships between climate and glacier mass balance is of considerable importance in understanding and modelling how temporal variability in climate affects the quantity of perennial snow and ice stored in glaciers, and the runoff from glacierised areas. Influences of year-to-year variations in air temperatures are pertinent in the absence of long records of measured energy balance and in view of predictions of future climate scenarios in terms of temperature. Measurements of temperature and precipitation from several stations in Alpine valleys in the Rhone basin, Wallis, Switzerland have been analysed to indicate trends in climate from 1930 to 1988. Actual measurements of mass balance of Griesgletscher, ablation calculated from runoff and net accumulation estimated from totalising rain gauges for Findelengletscher and Gornergletscher beginning in the late 1960s, and runoff from Aletschgletscher since 1930, were taken as annual glaciological responses to climatic variation. Variables to represent climatic elements and interactions between precipitation and temperature were selected according to degree of correlation with glacier response variables, and climate-glacier response relationships were assessed by multiple regression. Subsets of the data representing the coolest (1972–81) and warmest (1943–52) decades were also analysed to indicate whether relationships amongst climatic variables and between climate and mass balance remain the same under contrasting climatic conditions. Overall, mean summer air temperature variables for the months May through September and June through August provide the highest levels of explanation of variance of ablation and mass balance respectively (75–82%). Addition of a precipitation variable (winter, spring or summer) in multiple regression increases explanation to a maximum of 91%. Spring and summer precipitation variables are negatively correlated with ablation. Positive degree days and temperature-summer snow functions provide alternatives to temperature. Event-based analysis of the coolest and warmest years selected by rank order invokes high precipitation in May and low May-June temperatures and summer snowfall events as significant variables. Relationships between climatic variables indicate that warmer-than-average winters have higher precipitation, but at summer and annual time scales precipitation is slightly negatively associated with temperature. At the decadal level, warmer periods appear to be influenced by increased frequency of continental anticyclonic conditions, in an area subject to both maritime and continental influences. These analyses of climatic variables indicate that summer energy inputs dominate glacier mass balance. Relationships between precipitation and temperature are complex and were changeable during a fluctuation of about 1° over 40 years. Effects of a potentially warmer future on the form of precipitation in spring, summer and autumn are not clear, so estimates of changes of mass balance have been calculated for contrasting precipitation regimes.
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N. Collins, David. "Climatic Variables and Mass Balance Of Alpine Glaciers During A Period Of Climate Fluctuation." Annals of Glaciology 14 (1990): 333. http://dx.doi.org/10.3189/s0260305500008934.
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Parameterisation of relationships between climate and glacier mass balance is of considerable importance in understanding and modelling how temporal variability in climate affects the quantity of perennial snow and ice stored in glaciers, and the runoff from glacierised areas. Influences of year-to-year variations in air temperatures are pertinent in the absence of long records of measured energy balance and in view of predictions of future climate scenarios in terms of temperature. Measurements of temperature and precipitation from several stations in Alpine valleys in the Rhone basin, Wallis, Switzerland have been analysed to indicate trends in climate from 1930 to 1988. Actual measurements of mass balance of Griesgletscher, ablation calculated from runoff and net accumulation estimated from totalising rain gauges for Findelengletscher and Gornergletscher beginning in the late 1960s, and runoff from Aletschgletscher since 1930, were taken as annual glaciological responses to climatic variation. Variables to represent climatic elements and interactions between precipitation and temperature were selected according to degree of correlation with glacier response variables, and climate-glacier response relationships were assessed by multiple regression. Subsets of the data representing the coolest (1972–81) and warmest (1943–52) decades were also analysed to indicate whether relationships amongst climatic variables and between climate and mass balance remain the same under contrasting climatic conditions.Overall, mean summer air temperature variables for the months May through September and June through August provide the highest levels of explanation of variance of ablation and mass balance respectively (75–82%). Addition of a precipitation variable (winter, spring or summer) in multiple regression increases explanation to a maximum of 91%. Spring and summer precipitation variables are negatively correlated with ablation. Positive degree days and temperature-summer snow functions provide alternatives to temperature. Event-based analysis of the coolest and warmest years selected by rank order invokes high precipitation in May and low May-June temperatures and summer snowfall events as significant variables.Relationships between climatic variables indicate that warmer-than-average winters have higher precipitation, but at summer and annual time scales precipitation is slightly negatively associated with temperature. At the decadal level, warmer periods appear to be influenced by increased frequency of continental anticyclonic conditions, in an area subject to both maritime and continental influences. These analyses of climatic variables indicate that summer energy inputs dominate glacier mass balance. Relationships between precipitation and temperature are complex and were changeable during a fluctuation of about 1° over 40 years. Effects of a potentially warmer future on the form of precipitation in spring, summer and autumn are not clear, so estimates of changes of mass balance have been calculated for contrasting precipitation regimes.
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Zhu, Xiuhua, Klaus Fraedrich, Zhengyu Liu, and Richard Blender. "A Demonstration of Long-Term Memory and Climate Predictability." Journal of Climate 23, no. 18 (September 15, 2010): 5021–29. http://dx.doi.org/10.1175/2010jcli3370.1.
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Abstract Climate forecast skills are evaluated for surface temperature time series at grid points of a millennium control simulation from a state-of-the-art global circulation model [ECHAM5–Max Planck Institute Ocean Model (MPI-OM)]. First, climate predictability is diagnosed in terms of potentially predictable variance fractions and the fluctuation power-law exponent (using detrended fluctuation analysis). Long-term memory (LTM) with a fluctuation exponent (or Hurst exponent) close to 0.9 occurs mainly in high-latitude oceans, which are also characterized by high potential predictability. Next, explicit prediction experiments for various time steps are conducted on a gridpoint basis using an autocorrelation predictor. In regions with LTM, prediction skills are beyond that expected from red noise persistence—exceptions occur in some areas in the southern oceans and over the Northern Hemisphere continents. Extending the predictability analysis to the fully forced simulation shows a large improvement in prediction skills.
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Boryczka, Jerzy, Maria Stopa-Boryczka, Arleta Unton-Pyziołek, and Piotr Gieszcz. "Cooling and Warming of Climate of the Earth’s Northern Hemisphere (On the Basis of Fluctuations of the Oxygen Isotope Δ18O and Dendrological Data)." Miscellanea Geographica 14, no. 1 (December 1, 2010): 47–58. http://dx.doi.org/10.2478/mgrsd-2010-0005.
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Abstract Content fluctuations of the oxygen isotope δ18O in the Devon Island ice core during the last 100 000 years are a measure of climate fluctuations in the Northern Hemisphere. The course of content of the oxygen isotope δ18O and the sums of solar radiation reaching the upper edge of the atmosphere are characterized by approximate minima and maxima (by positive correlation). This proves that, during the last hundred thousand years, climate fluctuations (cooling and warming) in the Northern Hemisphere were conditioned by long-term changes of the orbit and altitude of the Earth’s axis. Climate fluctuation forecasts for the Northern Hemisphere were developed for the next 40 000 years on the basis of the established periods of change of the oxygen isotope δ18O and the known solar radiation periodicity. Climate changes in Europe during the last 25000 years were presented together with a forecast for 1000 years (according to organic substances in deposits and radiation) as well as climate changes in Europe in the period from -500 years BP to 2100 AD (according to δ18O and pine tree-rings). It showed that climate changes depended on the concentration of planet mass in relation to the ecliptic plane (from the gravitational impact of planets on the Sun). Concentration courses of planet mass in the Solar System and climate fluctuations in the Northern Hemisphere were compared. Of interest are examples of synchronic fluctuations, i.e. dispersal of planet mass in the Solar System, the widths of pine and spruce tree rings and air temperatures in Europe.
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Javaid, Saher, Mineo Kaneko, and Yasuo Tan. "Structural Condition for Controllable Power Flow System Containing Controllable and Fluctuating Power Devices." Energies 13, no. 7 (April 2, 2020): 1627. http://dx.doi.org/10.3390/en13071627.
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This paper discusses a structural property for a power system to continue a safe operation under power fluctuation caused by fluctuating power sources and loads. Concerns over global climate change and gas emissions have motivated development and integration of renewable energy sources such as wind and solar to fulfill power demand. The energy generated from these sources exhibits fluctuations and uncertainty which is uncontrollable. In addition, the power fluctuations caused by power loads also have the same consequences on power system. To mitigate the effects of uncontrollable power fluctuations, a power flow control is presented which allocates power levels for controllable power sources and loads and connections between power devices. One basic function for the power flow control is to balance the generated power with the power demand. However, due to the structural limitations, i.e., the power level limitations of controllable sources and loads and the limitation of power flow channels, the power balance may not be achieved. This paper proposes two theorems about the structural conditions for a power system to have a feasible solution which achieves the power balance between power sources and power loads. The discussions in this paper will provide a solid theoretical background for designing a power flow system which proves robustness against fluctuations caused by fluctuating power devices.
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Degterev, Andrey Kharitonovich. "Changes in Crimea’s climate over the recent decades." Вопросы безопасности, no. 2 (February 2020): 1–6. http://dx.doi.org/10.25136/2409-7543.2020.2.32821.
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This article is dedicated to assessment of the climate changes of the Republic of Crimea over the last few decades. Throughout the analysis, the research utilized data on air temperature changes in the temperate latitudes of Europe by paleoclimatic data, as well as by changes in average temperature of surface waters in the Black Sea according coastal measurements. It is demonstrated that on the background of global warming there are natural manifestations of climatic fluctuations with periods of up to 20 years that relate to warm episodes such as El Niño and North-Atlantic fluctuation. The research methodology is based on the modern theory of global warming, which replaced the Milankovitch cycles concept used until the 1980’s. One of the main consequences of global warming for Russia lies in the significant increase in the frequency of reoccurrence of dangerous hydrometeorological phenomena. Examples of such phenomena include strong floods and heat waves. In a number of regions, the increase in temperature is also accompanied by spread of agents of dangerous diseases – ticks and marsh mosquitoes. However, the most notable damage caused by the climate change in Russia comes from drought.
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Khan, Saifullah, and Mahmood Ul Hasan. "Climate Classification of Pakistan." International Journal of Economic and Environmental Geology 10, no. 2 (September 4, 2019): 60–71. http://dx.doi.org/10.46660/ijeeg.vol10.iss2.2019.264.
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The research covenants amid the evaluation and analysis of the weather data in regards to mean monthlytemperature, precipitation, rainy days, relative humidity, wind direction, atmospheric pressure, evaporation, solarradiation and with the literature cited. The components getting fluctuation in the atmospheric condition comprise ofglobal location, vicinity to ocean, geomorphic reliefs and continental extent, maritime affects, forests and landuse.Based on the daily and monthly temperature, the study area has divided into five localities consisting of hot, warm,mild, cool, and cold. Besides, the five precipitation zones namely arid, semi-arid, sub-humid, humid andundifferentiated highlands have been distinguished during course of work. Generally, eastern longitudes of the countryget substantial downpours amid summers (monsoon season). Though the western areas in winters excluding GilgitBaltistan, where it is from local thunderstorms. Pakistan encounters four precipitation seasons namely winter, premonsoon, monsoon, and post monsoon rainfall. Because of sub-tropical vicinity, the country has experienced twofundamental seasons explicitly winter and summer. Generally, the summer period goes on for five months in mountainsand seven months in plains, whilst the winter period differs for seven months in mountains and five months in plains.The stated two essential rainy periods are auxiliary sub-isolated into four sub-spells to be precisely hot, warm, monsoonand cold season. Based on appropriation and fluctuation of climate variables, Pakistan is classified in five macro areasthat auxiliary sub-curved up into 18 meso and 46 micro scale climate regions.
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Khan, Saifullah, and Mahmood Ul Hasan. "Climate Classification of Pakistan." International Journal of Economic and Environmental Geology 10, no. 2 (September 4, 2019): 60–71. http://dx.doi.org/10.46660/ojs.v10i2.264.
Full textAbstract:
The research covenants amid the evaluation and analysis of the weather data in regards to mean monthlytemperature, precipitation, rainy days, relative humidity, wind direction, atmospheric pressure, evaporation, solarradiation and with the literature cited. The components getting fluctuation in the atmospheric condition comprise ofglobal location, vicinity to ocean, geomorphic reliefs and continental extent, maritime affects, forests and landuse.Based on the daily and monthly temperature, the study area has divided into five localities consisting of hot, warm,mild, cool, and cold. Besides, the five precipitation zones namely arid, semi-arid, sub-humid, humid andundifferentiated highlands have been distinguished during course of work. Generally, eastern longitudes of the countryget substantial downpours amid summers (monsoon season). Though the western areas in winters excluding GilgitBaltistan, where it is from local thunderstorms. Pakistan encounters four precipitation seasons namely winter, premonsoon, monsoon, and post monsoon rainfall. Because of sub-tropical vicinity, the country has experienced twofundamental seasons explicitly winter and summer. Generally, the summer period goes on for five months in mountainsand seven months in plains, whilst the winter period differs for seven months in mountains and five months in plains.The stated two essential rainy periods are auxiliary sub-isolated into four sub-spells to be precisely hot, warm, monsoonand cold season. Based on appropriation and fluctuation of climate variables, Pakistan is classified in five macro areasthat auxiliary sub-curved up into 18 meso and 46 micro scale climate regions.
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Lohmann, Gerrit. "ESD Ideas: The stochastic climate model shows that underestimated Holocene trends and variability represent two sides of the same coin." Earth System Dynamics 9, no. 4 (November 12, 2018): 1279–81. http://dx.doi.org/10.5194/esd-9-1279-2018.
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Abstract. Holocene sea surface temperature trends and variability are underestimated in models compared to paleoclimate data. The idea is presented that the local trends and variability are related, which is elaborated in a conceptual framework of the stochastic climate model. The relation is a consequence of the fluctuation–dissipation theorem, connecting the linear response of a system to its statistical fluctuations. Consequently, the spectrum can be used to estimate the timescale-dependent climate response. The non-normality in the propagation operator introduces enhanced long-term variability related to nonequilibrium and/or Earth system sensitivity. The simple model can guide us to analyze comprehensive models' behavior.
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He, Cheng, Youru Yao, Xiaoman Lu, Mingnan Chen, Weichun Ma, and Liguo Zhou. "Exploring the Influence Mechanism of Meteorological Conditions on the Concentration of Suspended Solids and Chlorophyll-a in Large Estuaries Based on MODIS Imagery." Water 11, no. 2 (February 21, 2019): 375. http://dx.doi.org/10.3390/w11020375.
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In estuary areas, meteorological conditions have become unstable under the continuous effects of climate change, and the ecological backgrounds of such areas have strongly been influenced by anthropic activities. Consequently, the water quality of these areas is obviously affected. In this research, we identified periods of fluctuation of the general meteorological conditions in the Yangtze River Estuary using a wavelet analysis. Additionally, we performed a spatiotemporal evaluation of the water quality in the fluctuating period by using remote sensing modeling. Then, we explored how the fluctuating meteorological factors affect the distribution of total suspended solids (TSS) and chlorophyll-a (Chla) concentration. (1) The results show that from 2000 to 2015, temperature did not present significant fluctuations, while wind speed (WS) and precipitation (PR) presented the same fluctuation period from January 2012 to December 2012. (2) Based on the measured water sample data associated with Moderate Resolution Imaging Spectroradiometer (MODIS) imagery, we developed a water quality algorithm and depicted the TSS and Chla concentrations within the WS and PR fluctuating period. (3) We found that the TSS concentration decreased with distance from the shore, while the Chla concentration showed an initially decreasing trend followed by an increasing trend; moreover, these two water quality parameters presented different inter-annual variations. Then, we discussed the correlation between the changes in the TSS and Chla concentrations and the WS and PR variables. The contribution of this research is reflected in two aspects: 1. variations in water quality parameters over a wide range of water bodies can be evaluated based on MODIS data; 2. data from different time periods showed that the fluctuations of meteorological elements had different impacts on water bodies based on the distance from the shore. The results provide new insights for the management of estuary water environments.
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Rypdal, Martin. "Early-Warning Signals for the Onsets of Greenland Interstadials and the Younger Dryas–Preboreal Transition." Journal of Climate 29, no. 11 (May 20, 2016): 4047–56. http://dx.doi.org/10.1175/jcli-d-15-0828.1.
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Abstract The climate system approaches a tipping point if the prevailing climate state loses stability, making a transition to a different state possible. A result from the theory of randomly driven dynamical systems is that the reduced stability in the vicinity of a tipping point is accompanied by increasing fluctuation levels and longer correlation times (critical slowing down) and can in principle serve as early-warning signals of an upcoming tipping point. This study demonstrates that the high-frequency band of the δ18O variations in the North Greenland Ice Core Project displays fluctuation levels that increase as one approaches the onset of an interstadial (warm) period. Similar results are found for the locally estimated Hurst exponent for the high-frequency fluctuations, signaling longer correlation times. The observed slowing down is found to be even stronger in the Younger Dryas, suggesting that both the Younger Dryas–Preboreal transition and the onsets of the Greenland interstadials are preceded by decreasing stability of the climate state. It is also verified that the temperature fluctuations during the stadial periods can be approximately modeled as a scale-invariant persistent noise, which can be approximated as an aggregation of processes that respond to perturbations on certain characteristic time scales. The results are consistent with the hypothesis that both the onsets of the Greenland interstadials and the Younger Dryas–Preboreal transition are caused by tipping points in dynamical processes with characteristic time scales on the order of decades and that the variability of other processes on longer time scales masks the early-warning signatures in the δ18O signal.
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Lanfredi, M., T. Simoniello, V. Cuomo, and M. Macchiato. "Discriminating low frequency components from long range persistent fluctuations in daily atmospheric temperature variability." Atmospheric Chemistry and Physics 9, no. 14 (July 15, 2009): 4537–44. http://dx.doi.org/10.5194/acp-9-4537-2009.
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Abstract. This study originated from recent results reported in literature, which support the existence of long-range (power-law) persistence in atmospheric temperature fluctuations on monthly and inter-annual scales. We investigated the results of Detrended Fluctuation Analysis (DFA) carried out on twenty-two historical daily time series recorded in Europe in order to evaluate the reliability of such findings in depth. More detailed inspections emphasized systematic deviations from power-law and high statistical confidence for functional form misspecification. Rigorous analyses did not support scale-free correlation as an operative concept for Climate modelling, as instead suggested in literature. In order to understand the physical implications of our results better, we designed a bivariate Markov process, parameterised on the basis of the atmospheric observational data by introducing a slow dummy variable. The time series generated by this model, analysed both in time and frequency domains, tallied with the real ones very well. They accounted for both the deceptive scaling found in literature and the correlation details enhanced by our analysis. Our results seem to evidence the presence of slow fluctuations from another climatic sub-system such as ocean, which inflates temperature variance up to several months. They advise more precise re-analyses of temperature time series before suggesting dynamical paradigms useful for Climate modelling and for the assessment of Climate Change.
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Lanfredi, M., T. Simoniello, V. Cuomo, and M. Macchiato. "Discriminating low frequency components from long range persistent fluctuations in daily atmospheric temperature variability." Atmospheric Chemistry and Physics Discussions 9, no. 1 (February 26, 2009): 5177–99. http://dx.doi.org/10.5194/acpd-9-5177-2009.
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Abstract. This study originated from recent results reported in literature, which support the existence of long-range (power-law) persistence in atmospheric temperature fluctuations on monthly and inter-annual scales. We investigated the results of Detrended Fluctuation Analysis (DFA) carried out on twenty-two historical daily time series recorded in Europe in order to evaluate the reliability of such findings in depth. More detailed inspections emphasized systematic deviations from power-law and high statistical confidence for functional form misspecification. Rigorous analyses did not support scale-free correlation as an operative concept for Climate modelling, as instead suggested in literature. In order to understand the physical implications of our results better, we designed a bivariate Markov process, parameterised on the basis of the atmospheric observational data by introducing a slow dummy variable. The time series generated by this model, analysed both in time and frequency domains, tallied with the real ones very well. They accounted for both the deceptive scaling found in literature and the correlation details enhanced by our analysis. Our results seem to evidence the presence of slow fluctuations from another climatic sub-system such as ocean, which inflates temperature variance up to several months. They advise more precise re-analyses of temperature time series before suggesting dynamical paradigms useful for Climate modelling and for the assessment of Climate Change.
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Degroot, Dagomar. "War of the Whales: Climate Change, Weather and Arctic Conflict in the Early Seventeenth Century." Environment and History 26, no. 4 (November 1, 2020): 549–77. http://dx.doi.org/10.3197/096734019x15463432086801.
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Beginning in 1580, average annual temperatures across the Arctic cooled amid the regional onset of the 'Grindelwald Fluctuation', a particularly cold but volatile period in the Little Ice Age. By contributing to socioeconomic trends that raised the cost of vegetable oils, climatic cooling encouraged European merchants to establish rival whaling operations around the frigid archipelago of Svalbard, roughly halfway between Norway and the North Pole. From 1611 until 1619, European whalers depended on temporary encampments set up along the shores of bays in the islands of Svalbard, and eventually the nearby island of Jan Mayen. When regional sea ice registered the climatic trends of the Grindelwald Fluctuation by besetting these bays, whalers from different European nations and companies coped by cooperating with one another. Yet when the volatility of the Grindelwald Fluctuation in the already variable climate of Svalbard and Jan Mayen drew ice away from the bays, violence often broke out between rival whalers and their escorting warships. Shifting environmental circumstances therefore played a previously ignored role in inciting and mitigating violence in the first decade of the Spitsbergen whaling industry. These relationships can offer new perspectives on the future of geopolitical competition in a warming Arctic.
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Kozlovsky, Dovid Y., Carrie L. Branch, Angela M. Pitera, and Vladimir V. Pravosudov. "Fluctuations in annual climatic extremes are associated with reproductive variation in resident mountain chickadees." Royal Society Open Science 5, no. 5 (May 2018): 171604. http://dx.doi.org/10.1098/rsos.171604.
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Mounting evidence suggests that we are experiencing rapidly accelerating global climate change. Understanding how climate change may affect life is critical to identifying species and populations that are vulnerable. Most current research focuses on investigating how organisms may respond to gradual warming, but another effect of climate change is extreme annual variation in precipitation associated with alternations between drought and unusually heavy precipitation, like that exhibited in the western regions of North America. Understanding climate change effects on animal reproductive behaviour is especially important, because it directly impacts population persistence. Here, we present data on reproduction in nest-box breeding, resident mountain chickadees inhabiting high and low elevations in the Sierra Nevada across 5 years. These 5 years of data represent the full range of climatic variation from the largest drought in five centuries to one of the heaviest snow years on record. There were significant differences in most reproductive characteristics associated with variation in climate. Both climate extremes were negatively associated with reproductive success at high and low elevations, but low-elevation chickadees had worse reproductive success in the largest drought year while high-elevation chickadees had worse reproductive success in the heaviest snow year. Considering that the frequency of extreme climate swings between drought and snow is predicted to increase, such swings may have negative effects on chickadee populations across the entire elevation gradient, as climatic extremes should favour different adaptations. Alternatively, it is possible that climate fluctuations might favour preserving genetic variation allowing for higher resilience. It is too early to make specific predictions regarding how increased frequency of extreme climate fluctuation may impact chickadees; however, our data suggest that even the most common species may be susceptible.
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Cascione, Valeria, Carl-Eric Hagentoft, Daniel Maskell, Andy Shea, and Pete Walker. "Moisture Buffering in Surface Materials Due to Simultaneous Varying Relative Humidity and Temperatures: Experimental Validation of New Analytical Formulas." Applied Sciences 10, no. 21 (October 29, 2020): 7665. http://dx.doi.org/10.3390/app10217665.
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Buildings are subjected to the indoor environment, especially in non-controlled climates. Temperature and humidity variations might effect or even damage materials sensitive to moisture. For this reason, it is important to understand the response of hygroscopic materials to variable indoor environmental conditions. Existing methods looked into the dynamic sorption capacity of materials, by analysing the impact of only humidity fluctuations, with temperature usually considered non-influential or non variable. However, temperature fluctuations may impact the moisture capacity of the materials, as materials properties might substantially vary with temperature. Moreover, in existing protocols, the humidity variations are considered to be varying under square wave fluctuations, which may not be applicable in environments, where the indoor is influenced by daily and seasonal climate variations, which presents more complex fluctuation. In this study, a simulation method that can predict the impact of environmental condition on materials under simultaneous temperature and humidity fluctuations was developed. Clay and gypsum plaster were analysed in the numerical model and results were then validated with experimental data. Materials were subjected to either sinusoidal and triangular temperature and RH variations and different cycle time intervals. The investigation of sinusoidal and triangular environmental variations pushed to a better understanding of materials response to different environments and to the improvement of the simplified model. The development of a simplified model can realistically predict the potential future impact of climate changes on buildings without the use of complex and memory demanding computational methods.
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Lovejoy, Shaun. "How scaling fluctuation analysis transforms our view of the climate." Past Global Changes Magazine 25, no. 3 (December 2017): 136–37. http://dx.doi.org/10.22498/pages.25.3.136.
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Kühl, Hjalmar S., Antoine N'Guessan, Julia Riedel, Sonja Metzger, and Tobias Deschner. "The Effect of Climate Fluctuation on Chimpanzee Birth Sex Ratio." PLoS ONE 7, no. 4 (April 26, 2012): e35610. http://dx.doi.org/10.1371/journal.pone.0035610.
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Perriman, Lyndon, Dave Houston, Harald Steen, and Edda Johannesen. "Climate fluctuation effects on breeding of blue penguins (Eudyptula minor)." New Zealand Journal of Zoology 27, no. 4 (January 2000): 261–67. http://dx.doi.org/10.1080/03014223.2000.9518234.
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Wei, Qi, Yuanyuan Bian, and Xuejuan Yang. "Influencing factors of price fluctuation in China’s carbon market." E3S Web of Conferences 218 (2020): 01044. http://dx.doi.org/10.1051/e3sconf/202021801044.
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Carbon emission trading is an important countermeasure for countries around the world to cope with the challenge of climate change. Price signals in the carbon market play an important stabilizing role. Therefore, research on the factors affecting carbon price fluctuations is of great significance. Based on this, an empirical study on the fluctuation factors of carbon price in China’s pilot carbon market showed that: gross industrial output, coal consumption and the number of extreme weather have a positive impact on carbon prices, while the technology innovation index has a negative impact on carbon prices. This article puts forward suggestions on the construction of the carbon market, stabilizes carbon prices, and promotes the development of China’s carbon market.
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Lewandowsky, Stephan, James S. Risbey, and Naomi Oreskes. "The “Pause” in Global Warming: Turning a Routine Fluctuation into a Problem for Science." Bulletin of the American Meteorological Society 97, no. 5 (May 1, 2016): 723–33. http://dx.doi.org/10.1175/bams-d-14-00106.1.
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Abstract There has been much recent published research about a putative “pause” or “hiatus” in global warming. We show that there are frequent fluctuations in the rate of warming around a longer-term warming trend, and that there is no evidence that identifies the recent period as unique or particularly unusual. In confirmation, we show that the notion of a pause in warming is considered to be misleading in a blind expert test. Nonetheless, the most recent fluctuation about the longer-term trend has been regarded by many as an explanatory challenge that climate science must resolve. This departs from long-standing practice, insofar as scientists have long recognized that the climate fluctuates, that linear increases in CO2 do not produce linear trends in global warming, and that 15-yr (or shorter) periods are not diagnostic of long-term trends. We suggest that the repetition of the “warming has paused” message by contrarians was adopted by the scientific community in its problem-solving and answer-seeking role and has led to undue focus on, and mislabeling of, a recent fluctuation. We present an alternative framing that could have avoided inadvertently reinforcing a misleading claim.
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Taeb, Arshia, and Phillip S. K. Ooi. "Comparison of Field Behavior with Results from Numerical Analysis of a Geosynthetic Reinforced Soil Integrated Bridge System Subjected to Thermal Effects." Transportation Research Record: Journal of the Transportation Research Board 2674, no. 1 (January 2020): 294–306. http://dx.doi.org/10.1177/0361198119899043.
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When subjected to ambient daily temperature fluctuations, a 109.5 ft-long geosynthetic reinforced soil integrated bridge system (GRS-IBS) was observed to undergo cyclic straining of the superstructure. The upper and lower reaches of the superstructure experienced the highest and lowest strain fluctuation, respectively. These non-uniform strains impose not only axial loading of the superstructure but also bending. Pure axial loading in a horizontal superstructure will cause the footings to slide. However, bending in the superstructure will cause the footings to rotate thereby inducing cyclic fluctuations of the vertical pressure beneath the footing and also lateral pressure behind the end walls. Measured vertical footing pressure closest to the stream experienced the greatest daily pressure fluctuation (≈ 2,500–3,000 psf), while that nearest the end wall experienced the least. The toe pressure fluctuations seem rather large. That these large vertical pressure fluctuations are observed in a tropical climate like Hawaii when no other GRS-IBS in temperate regions has reported the same (or perhaps higher fluctuation) is indeed surprising. The larger these pressures are, the greater the likelihood of inducing cyclic-induced deformations of the GRS abutment. A finite element analysis of the same GRS-IBS was performed by applying an equivalent temperature and gradient to the superstructure over the coldest and hottest periods of a day to see if the field measured values of pressures are reasonable and verifiable, which indeed they were. This methodology is novel in the sense that the effects of axial load and bending of the superstructure are simulated using measured strains rather than measured temperatures.
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Tomita, Tomohiko, Takao Yoshikane, and Tetsuzo Yasunari. "Biennial and Lower-Frequency Variability Observed in the Early Summer Climate in the Western North Pacific." Journal of Climate 17, no. 21 (November 1, 2004): 4254–66. http://dx.doi.org/10.1175/jcli3200.1.
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Abstract Early summer climate in the western North Pacific is largely represented by the baiu phenomenon. The meridional fluctuations of the baiu front on interannual time scales and the associated large-scale circulations are examined using the empirical orthogonal function (EOF) analysis and composite or correlation analyses based on the EOF time coefficients. The first EOF mode indicates a 5- or 6-yr low-frequency fluctuation (LF mode) appearing south of 35°N. The development is concurrent with horseshoe sea surface temperature anomalies (SSTAs) in the entire tropical Pacific that are associated with the El Niño–Southern Oscillation (ENSO). SSTAs in the western North Pacific control the anomalous southward expansion of the baiu front through a modification of the convection at around 20°–35°N. The LF mode is negatively correlated with the south-southeast Asian summer monsoon. The second EOF mode is characterized by a meridional seesawlike fluctuation with a node at around 28°N and a time scale of biennial oscillation (BO mode). The horseshoe SSTAs again control the anomalous meridional circulations, but with a different spatial phase through a convection off the Philippines. The spatial phase difference between the two horseshoe patterns is about 90° in both the zonal and meridional directions. The BO mode is negatively correlated with the tropical western North Pacific monsoon. SSTAs associated with the BO mode tend to be confined to the tropical western Pacific, while the signals of the LF mode extend rather broadly in the tropical Pacific–Indian Ocean sector, suggesting that the tropical BO is an aborted ENSO in the tropical central–western Pacific. The spatial phase of horseshoe SSTAs adjusts the interannual variability of the meridional fluctuation of the baiu front in the western North Pacific.
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LACORATA, GUGLIELMO, ANDREA PUGLISI, and ANGELO VULPIANI. "ON THE FLUCTUATION-RESPONSE RELATION IN GEOPHYSICAL SYSTEMS." International Journal of Modern Physics B 23, no. 28n29 (November 20, 2009): 5515–29. http://dx.doi.org/10.1142/s0217979209063821.
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One of the major issues concerning the study of a dynamical system is the response to perturbations. In climate dynamics, for example, it is of major interest to understand how a given variable, e.g., the temperature, is sensitive to alterations of some other component of the system, e.g., the greenhouse gas concentration. We review the connection between equilibrium and non-equilibrium properties, also known as Fluctuation-Relaxation Relation, and its main aspects in chaotic and turbulent systems. We consider, in particular, the effects of the fast variables on the slow variables in a multiscale system, as far as the sensitivity properties are concerned. Two examples about (widely speaking) climate modelling are discussed: the Lorenz-96 model and the double-potential well model. Both of them, despite their apparent simplicity, hide the same kind of interesting features of much more complex systems.
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Devkota, Thakur. "Climate Change and its Impact on Tourism Based Livelihood in High Mountain of Nepal." Journal of Development and Administrative Studies 25, no. 1-2 (December 31, 2017): 11–23. http://dx.doi.org/10.3126/jodas.v25i1-2.23435.
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The climate change is the major issue of the development planning in recent world. This paper focuses on the people’s understanding and experience about the climate change, its impact on tourism dependent livelihoods of the mountain community. Participatory survey design, interview, community consultation, FGD, were conducted in the field. The literature review and hydrological and meteorological data from secondary source were collected for analysis. The people of research area feel that the fluctuation of climatic variables and extremes is occurring now and they are familiar with that change in climatic variables and associated disaster. Their experience on the warming and precipitation coincides with authorized meteorological data which depicts that the mean annual temperature is increasing and average annual precipitation is decreasing. People from High mountain region said that the impact of climate change in tourism based livelihood was experienced. All types of livelihood assets are affected by climate change in mountain region. The change in frequency and intensity of climatic variables and climate change induced hazards was observed and that retard in tourism business and tourism activities in local area.
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Majda, Andrew J., Boris Gershgorin, and Yuan Yuan. "Low-Frequency Climate Response and Fluctuation–Dissipation Theorems: Theory and Practice." Journal of the Atmospheric Sciences 67, no. 4 (April 1, 2010): 1186–201. http://dx.doi.org/10.1175/2009jas3264.1.
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Abstract The low-frequency response to changes in external forcing or other parameters for various components of the climate system is a central problem of contemporary climate change science. The fluctuation–dissipation theorem (FDT) is an attractive way to assess climate change by utilizing statistics of the present climate; with systematic approximations, it has been shown recently to have high skill for suitable regimes of an atmospheric general circulation model (GCM). Further applications of FDT to low-frequency climate response require improved approximations for FDT on a reduced subspace of resolved variables. Here, systematic mathematical principles are utilized to develop new FDT approximations on reduced subspaces and to assess the small yet significant departures from Gaussianity in low-frequency variables on the FDT response. Simplified test models mimicking crucial features in GCMs are utilized here to elucidate these issues and various FDT approximations in an unambiguous fashion. Also, the shortcomings of alternative ad hoc procedures for FDT in the recent literature are discussed here. In particular, it is shown that linear regression stochastic models for the FDT response always have no skill for a general nonlinear system for the variance response and can have poor or moderate skill for the mean response depending on the regime of the Lorenz 40-model and the details of the regression strategy. New nonlinear stochastic FDT approximations for a reduced set of variables are introduced here with significant skill in capturing the effect of subtle departures from Gaussianity in the low-frequency response for a reduced set of variables.
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Wei, Ren-juan, Liang Peng, Chuan Liang, Christoph Haemmig, Matthias Huss, Zhen-xia Mu, and Ying He. "Analysis of temporal and spatial variations in hydrometeorological elements in the Yarkant River Basin, China." Journal of Water and Climate Change 10, no. 1 (May 7, 2018): 167–80. http://dx.doi.org/10.2166/wcc.2018.111.
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Abstract Yarkant River is a tributary of Tarim River in China, and the basin lacks observational data. To investigate past climatic variations and predict future climate changes, precipitation, air temperature and runoff data from Kaqun hydrological station are analysed at monthly and seasonal scales using detrended fluctuation analysis (DFA). Results show that DFA scaling exponents of monthly precipitation, air temperature and runoff are 0.535, 0.662 and 0.582, respectively. These three factors all show long-range correlations. Their increasing trends will continue in the near future as the climate shifts towards warmer and more humid. Spring and winter precipitation exhibit long-range correlations and will increase in the future. In contrast, summer and autumn precipitation exhibits random fluctuations and does not show stable trends. Air temperature during all seasons exhibits long-range correlations and will continue to increase in the future. Runoff during the spring and summer exhibits weak anti-persistence, but autumn and winter runoff show long-range correlations and increasing trends. The vertical distribution of precipitation was first analysed using observed data and climate reanalysis data. It indicates that precipitation increases with elevations below 2,000 m a.s.l. at a rate of 26 mm per 100 m and decreases with elevations above 2,000 m a.s.l.
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Paradava, D. M., and H. D. Rank. "Groundwater Resources as Influenced by Climatic Change in Shetrunji basin of Gujarat State, India." Current World Environment 10, no. 3 (December 25, 2015): 994–1003. http://dx.doi.org/10.12944/cwe.10.3.31.
Full textAbstract:
The estimation of climatic alteration influencing on groundwater recharge will help to prepare a future plan for groundwater development and management planning for the basin. It will also be helpful for agriculture as well as other resource planning. The required shift in cropping pattern can also be judged. The study was undertaken for Shetrunji river basin having an area of 5646.98 km2. The entire area was found consisting of 17 watersheds. The climate change impact on Rainfall, Runoff and estimated groundwater recharge by 3 different methods were assessed. The groundwater recharge varied from 3.11% to 49.28%, 0% to 15.34% and 0.72% to 14.62% of rainfall by water balance, Krishna Rao (1970) and water table variation respectively. The climate change impacts favors to increase the rainfall significantly in 6 out of 17 watersheds while the runoff is found increasing in 5 out of 17 watersheds of the basin. The rainfall and runoff was influenced by the climate change in Northern part of upper reach and southernmost part of middle reach of basin. The area weighted rainfall of the Shetrunji river basin was found increasing significantly. The areal mean depth of monsoon runoff for entire Shetrunji basin was increasing significantly at the rate of 17.7 mm per decade. The groundwater recharge assessed by water balance method was found higher as compared to Krishna Rao (1970) and water level fluctuation method. The groundwater recharge expected by water balance, Krishna Rao (1970) and water level fluctuation methods is found to be enlarged in 13, 9 and 6 watersheds out of 17 watershed of the basin. The areal mean depth of groundwater recharge in Shetrunji basin during monsoon season in water level fluctuation method was found increasing significantly at the rate of 13.01 mm per decade due to climate change impacts.
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Abobatta, Waleed Fouad. "Managing citrus orchards under climate change." MOJ Ecology & Environmental Sciences 6, no. 2 (April 16, 2021): 43–44. http://dx.doi.org/10.15406/mojes.2021.06.00212.
Full textAbstract:
Citrus occupies the third position in fruit crop production worldwide after grapes and apple, while, citrus ranking the first position in world trading. Citrus fruits one of the popular fruits globally for their taste and flavor, currently there is more interested in citrus fruit consumption particularly under the COVID-19 pandemic due to higher Vitamin C content. Citrus are growing in warm climates from tropical to arid conditions in a wide range of temperatures ranging from 10˚C to 35˚C, while, Mediterranean climate is considered the most proper climate for citrus growth and productivity. Citrus has three or four growth cycle depending on climate conditions and water availability, Generally, vegetative growth starts with warm weather up to 12.8˚C and growth increase continuously with increasing temperature up to 35˚C, while, growth decline with rising temperature more than 35˚C. Due to harsh climate conditions, there is a fluctuation in citrus production and annually drastic yield loss, because of rising temperature and water shortage, which causes weakening growth, flowering, and productivity of citrus.
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Pelletier, Fanie, Kelly Moyes, Tim H. Clutton-Brock, and Tim Coulson. "Decomposing variation in population growth into contributions from environment and phenotypes in an age-structured population." Proceedings of the Royal Society B: Biological Sciences 279, no. 1727 (June 29, 2011): 394–401. http://dx.doi.org/10.1098/rspb.2011.0827.
Full textAbstract:
Evaluating the relative importance of ecological drivers responsible for natural population fluctuations in size is challenging. Longitudinal studies where most individuals are monitored from birth to death and where environmental conditions are known provide a valuable resource to characterize complex ecological interactions. We used a recently developed approach to decompose the observed fluctuation in population growth of the red deer population on the Isle of Rum into contributions from climate, density and their interaction and to quantify their relative importance. We also quantified the contribution of individual covariates, including phenotypic and life-history traits, to population growth. Fluctuations in composition in age and sex classes ((st)age structure) of the population contributed substantially to the population dynamics. Density, climate, birth weight and reproductive status contributed less and approximately equally to the population growth. Our results support the contention that fluctuations in the population's (st)age structure have important consequences for population dynamics and underline the importance of including information on population composition to understand the effect of human-driven changes on population performance of long-lived species.