To see the other types of publications on this topic, follow the link: Synoptic weather station.
Journal articles on the topic 'Synoptic weather station'
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 'Synoptic weather station.'
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
Tajbakhsh, S., P. Ghafarian, and F. Sahraian. "Instability indices and forecasting thunderstorms: the case of 30 April 2009." Natural Hazards and Earth System Sciences 12, no. 2 (February 17, 2012): 403–13. http://dx.doi.org/10.5194/nhess-12-403-2012.
Full textAbstract:
Abstract. In this paper, one meteorological case study for two Iranian airports are presented. Attempts have been made to study the predefined threshold amounts of some instability indices such as vertical velocity and relative humidity. Two important output variables from a numerical weather prediction model have been used to survey thunderstorms. The climatological state of thunder days in Iran has been determined to aid in choosing the airports for the case studies. The synoptic pattern, atmospheric thermodynamics and output from a numerical weather prediction model have been studied to evaluate the occurrence of storms and to verify the threshold instability indices that are based on Gordon and Albert (2000) and Miller (1972). Using data from the Statistics and Data Center of the Iran Meteorological Organization, 195 synoptic stations were used to study the climatological pattern of thunderstorm days in Iran during a 15-yr period (1991–2005). Synoptic weather maps and thermodynamic diagrams have been drawn using data from synoptic stations and radiosonde data. A 15-km resolution version of the WRF numerical model has been implemented for the Middle East region with the assistance of global data from University Corporation for Atmospheric Research (UCAR). The Tabriz airport weather station has been selected for further study due to its high frequency of thunderstorms (more than 35 thunderstorm days per year) and the existence of an upper air station. Despite the fact that storms occur less often at the Tehran weather station, the station has been chosen as the second case study site due to its large amount of air traffic. Using these two case studies (Tehran at 00:00 UTC, 31 April 2009 and Tabriz at 12:00 UTC, 31 April 2009), the results of this research show that the threshold amounts of 30 °C for KI, −2 °C for LI and −3 °C for SI suggests the occurrence and non-occurrence of thunderstorms at the Tehran and Tabriz stations, respectively. The WRF model output of vertical velocity and relative humidity are the two most important indices for examining storm occurrence, and they have a numerical threshold of 1 m s−1 and 80%, respectively. These results are comparable to other studies that have examined thunderstorm occurrence.
2
Szegedi, S., I. Lázár, and T. Tóth. "Relationships between macrosynoptic weather types and development of the thermal excess in suburban areas in Debrecen, Hungary." International Review of Applied Sciences and Engineering 5, no. 2 (December 1, 2014): 167–72. http://dx.doi.org/10.1556/irase.5.2014.2.9.
Full textAbstract:
Impacts of macrosynoptic weather patterns on the development of the thermal excess in suburban areas of Debrecen are examined in this paper. Temperature datasets have been recorded at two heights by three automatic weather stations mounted in Debrecen (east Hungary) and a small settlement in its vicinity. An additional automatic weather station is used as a reference station outside Debrecen. Urban heat island (UHI) intensities have been calculated from the raw datasets. Impacts of synoptic conditions have been analyzed on the base of Péczely’s macrosynoptic types. It has been found that anticyclone types are more favorable from the aspect of UHI development, while cyclone types, especially the passage of warm fronts can effectively hinder the formation of strong heat islands in Debrecen.
3
Xia, Zhengyu, Nicolás Butorovic, and Zicheng Yu. "The Influence of Synoptic Weather Types and Moisture Transport Pathways on Precipitation Isotopes in Southern Patagonia." Atmosphere 11, no. 5 (May 16, 2020): 514. http://dx.doi.org/10.3390/atmos11050514.
Full textAbstract:
We analyzed 28-year-long monthly oxygen isotope composition of precipitation (δ18Op) data from Punta Arenas (Chile) on the leeward side of the Andes to understand how different synoptic weather types and moisture transport pathways influence δ18Op variability in this region. Combining weather station 6 h precipitation data and atmospheric back trajectories, we found that in such a region where the atmospheric circulation pattern is dominated by very strong westerlies, an increased monthly proportion of easterly-delivered precipitation—with the air-mass trajectory path evading the influence of Andean “isotopic rain shadow” and having less rainout en route—would increase δ18Op. These synoptic easterlies are a result of quasi-stationary blocking-like flow that are an important but underappreciated part of regional circulation patterns and climate. In addition, synoptic easterlies are more often associated with heavy precipitation events as shown by weather station data and higher deuterium excess that indicates weaker post-condensation raindrop re-evaporation. Therefore, our analysis demonstrated the process link between the frequency of synoptic weather types characterized by blocking-like flow and temporal variations in δ18Op in Southern Patagonia. We conclude that isotope proxy paleo-records in this region could provide unique insights into the behaviors and dynamics of the large-scale Southern Hemisphere Westerly Winds over long timescales.
4
Gabała, Jarosław. "State Higher Vocational School Weather Station in Tarnów." Science, Technology and Innovation 1, no. 1 (December 27, 2017): 74–83. http://dx.doi.org/10.5604/01.3001.0010.7618.
Full textAbstract:
In 2015 the State Higher Vocational School in Tarnów (PWSZ), under the Norwegian Project implemented in the Department of Environmental Protection, purchased and set in motion semi-professional automatic weather station DAVIS Vantage Pro2. The station measures basic meteorological elements e.g. air temperature, wind speed and direction or solar radiation. The logged data are intended for teaching at the School, including the specialization of environmental protection. Comparison of the data acquired at the PWSZ station and at the synoptic station of Institute of Meteorology and Water Management (IMGW) allowed the evaluation of the correlation of the measurement series of both stations. Furthermore it allowed for the initial analysis of the urban heat island (MWC) as one of the aspects of the local climate. There are confirmed typical thermal marks of the urban heat island during favourable weather conditions with radiation cooling at night. Especially during cloudless and windless radiation night, the air cools down more at the rural areas, and this favours the occurrence of the urban heat island phenomenon. The urban – rural thermal contrasts are then the greatest, up to 3 °C. In the daytime difference between the centre and the outskirts of the city is quite small (under 1 °C), so generally the urban heat island doesn’t occur during the day.
5
Bari, Driss, Thierry Bergot, and Mohamed El Khlifi. "Local Meteorological and Large-Scale Weather Characteristics of Fog over the Grand Casablanca Region, Morocco." Journal of Applied Meteorology and Climatology 55, no. 8 (August 2016): 1731–45. http://dx.doi.org/10.1175/jamc-d-15-0314.1.
Full textAbstract:
AbstractUsing a fog event approach, the local meteorological and synoptic characteristics of fogs that formed over the Grand Casablanca (GCB) region during a 9-yr period (2001–09) are investigated. A climatological study of fog, with emphasis on the fog temporal variability and spatial distribution, is carried out on the basis of hourly surface meteorological observations at two synoptic stations in the region. The fog events are classified into fog types, using an objective classification algorithm, and are characterized by their duration, intensity, and times of onset and dissipation. In addition, fog events are classified into two distinct categories (isolated and widespread) on the basis of their spatial extent. K-means cluster analysis is applied to the patterns of mean sea level pressure in ERA-Interim reanalyses at 0000 UTC to determine the synoptic circulation types associated with fog occurrence in the GCB region. Results show that the fog frequency at the inland suburban station is more recurrent than at the coastal urban station. The fog events are predominantly of the advection–radiation type, with a marked tendency of nighttime occurrence during the winter. The spatial distribution analysis points out the localized character of fog and reveals the possibility of different fog types occurring when fog is present near the two stations simultaneously. Furthermore, the interaction between local- and large-scale mechanisms suggests that advective processes associated with sea-breeze circulation during daytime, followed by radiative processes early in the night, often lead to fog formation over the GCB region.
6
Nigro, Melissa A., John J. Cassano, and Mark W. Seefeldt. "A Weather-Pattern-Based Approach to Evaluate the Antarctic Mesoscale Prediction System (AMPS) Forecasts: Comparison to Automatic Weather Station Observations." Weather and Forecasting 26, no. 2 (April 1, 2011): 184–98. http://dx.doi.org/10.1175/2010waf2222444.1.
Full textAbstract:
Abstract Typical model evaluation strategies evaluate models over large periods of time (months, seasons, years, etc.) or for single case studies such as severe storms or other events of interest. The weather-pattern-based model evaluation technique described in this paper uses self-organizing maps to create a synoptic climatology of the weather patterns present over a region of interest, the Ross Ice Shelf for this analysis. Using the synoptic climatology, the performance of the model, the Weather Research and Forecasting Model run within the Antarctic Mesoscale Prediction System, is evaluated for each of the objectively identified weather patterns. The evaluation process involves classifying each model forecast as matching one of the weather patterns from the climatology. Subsequently, statistics such as model bias, root-mean-square error, and correlation are calculated for each weather pattern. This allows for the determination of model errors as a function of weather pattern and can highlight if certain errors occur under some weather regimes and not others. The results presented in this paper highlight the potential benefits of this new weather-pattern-based model evaluation technique.
7
Chen, Biyan, Wujiao Dai, Zhizhao Liu, Lixin Wu, Cuilin Kuang, and Minsi Ao. "Constructing a precipitable water vapor map from regional GNSS network observations without collocated meteorological data for weather forecasting." Atmospheric Measurement Techniques 11, no. 9 (September 11, 2018): 5153–66. http://dx.doi.org/10.5194/amt-11-5153-2018.
Full textAbstract:
Abstract. Surface pressure (Ps) and weighted mean temperature (Tm) are two necessary variables for the accurate retrieval of precipitable water vapor (PWV) from Global Navigation Satellite System (GNSS) zenith total delay (ZTD) estimates. The lack of Ps or Tm information is a concern for those GNSS sites that are not collocated with meteorological sensors. This paper investigates an alternative method of inferring accurate Ps and Tm at the GNSS station using nearby synoptic observations. Ps and Tm obtained at the nearby synoptic sites are interpolated onto the location of the GNSS station by performing both vertical and horizontal adjustments, in which the parameters involved in Ps and Tm calculation are estimated from ERA-Interim reanalysis profiles. In addition, we present a method of constructing high-quality PWV maps through vertical reduction and horizontal interpolation of the retrieved GNSS PWVs. To evaluate the performances of the Ps and Tm retrieval, and the PWV map construction, GNSS data collected from 58 stations of the Hunan GNSS network and synoptic observations from 20 nearby sites in 2015 were processed to extract the PWV so as to subsequently generate the PWV maps. The retrieved Ps and Tm and constructed PWV maps were assessed by the results derived from radiosonde and the ERA-Interim reanalysis. The results show that (1) accuracies of Ps and Tm derived by synoptic interpolation are within the range of 1.7–3.0 hPa and 2.5–3.0 K, respectively, which are much better than the GPT2w model; (2) the constructed PWV maps have good agreements with radiosonde and ERA-Interim reanalysis data with the overall accuracy being better than 3 mm; and (3) PWV maps can well reveal the moisture advection, transportation and convergence during heavy rainfall.
8
Láska, Kamil, Zuzana Chládová, Klára Ambrožová, and Jan Husák. "Cloudiness and weather variation in central Svalbard in July 2013 as related to atmospheric circulation." Czech Polar Reports 3, no. 2 (June 1, 2013): 184–95. http://dx.doi.org/10.5817/cpr2013-2-19.
Full textAbstract:
The paper describes synoptic situations and associated weather conditions in the central part of the Svalbard Arctic archipelago (Petuniabukta, Billefjorden) during two weeks of the summer 2013. The circulation types in July 2013 were compared with the long-term average circulation pattern in the period 1961–2010. Cloudiness and weather conditions in different atmospheric circulation types were described. Atmospheric pressure, 2-m air temperature, precipitation, 6-m wind speed and wind direction data from an automatic weather station located on the coastal glacier-free zone of Petuniabukta were used for further analysis. From July 5 to 19, 2013, radiation and advection weather types, heavy precipitation, rapid change of wind speed, 2-m air temperature and high cloudiness variation were described in detail within of the five most frequent synoptic situations. Foehn and halo phenomena were also reported in the study period.
9
Liu, Yihui, Fei Li, and Weifeng Hao. "Evaluation of Seasonal and Synoptic Changes in Snow Accumulation in Antarctica between Five Reanalyses Products and In Situ Observations." Atmosphere 9, no. 12 (December 3, 2018): 473. http://dx.doi.org/10.3390/atmos9120473.
Full textAbstract:
The performance of recent reanalysis products (i.e., ERA-Interim, NCEP2, MERRA, CFSR, and JRA-55) was evaluated based on in situ observations from nine automatic weather stations and one stake network to investigate the monthly and seasonal variability of the surface mass balance in Antarctica. Synoptic precipitation simulations were also evaluated by an investigation of high precipitation events. The seasonal variations showed large fluctuations and were inconsistent at each station, probably owing to the large interannual variability of snow accumulation based on the short temporal coverage of the data. The ERA-Interim and JRA-55 datasets revealed better simulated precision, with the other three models presenting similar simulations at monthly and seasonal timescales. The JRA-55 dataset captured a greater number of synoptic high precipitation events at four of the nine stations. Such events at the other five stations were mainly captured by ERA and CFSR. The NCEP2 dataset was more weakly correlated with each station on all timescales. These results indicate that significant monthly or seasonal correlations between in situ observations and the models had little effect on the capability of the reanalyses to capture high precipitation events. The precision of the five reanalysis datasets widely fluctuated in specific regions or at specific stations at different timescales. Great caution is needed when using a single reanalysis dataset to assess the surface mass balance over all of Antarctica.
10
Pereira, S. C., A. C. Carvalho, J. Ferreira, J. P. Nunes, J. J. Keizer, and A. Rocha. "Simulation of a persistent medium-term precipitation event over the western Iberian Peninsula." Hydrology and Earth System Sciences 17, no. 10 (October 2, 2013): 3741–58. http://dx.doi.org/10.5194/hess-17-3741-2013.
Full textAbstract:
Abstract. This study evaluated the performance of the WRF-ARW (Weather Research and Forecasting with Advanced Research) weather prediction model in simulating the spatial and temporal patterns of an extreme rainfall period over a complex orographic region in north-central Portugal. The analysis was performed during the rainy season and, more specifically, the month of December 2009. In this period, the region of interest was under the influence of a sequential passage of low-pressure systems associated with frontal surfaces. These synoptic weather patterns were responsible for long periods of rainfall, resulting in a high monthly precipitation. The WRF model results during the study period were furthermore evaluated with the specific objective to complement gaps in the precipitation recordings of a reference meteorological station (located in Pousadas), the data of which are fundamental for hydrological studies in nearby experimental catchments. Three distinct WRF model runs were forced with initial fields and boundary conditions obtained from a global domain model: (1) a reference experiment with no nudging (RunRef); (2) observational nudging for a specific location, i.e. the above-mentioned Pousadas reference station (RunObsN); and (3) nudging to the analysed field (RunGridN). Model performance was evaluated, using several statistical parameters, against a dataset of 27 rainfall stations that were grouped by elevation. The three model runs had similar performances, even though RunGridN resulted in a slight improvement. Regarding the other two experiments, this improvement justifies its use for complementing the surface measurements at the Pousadas reference station. Overall model accuracy, expressed in root mean square error (RMSE), of the three runs was comparable for the stations of the different elevations classes. Even so, it was slightly better for stations in the lowlands than the highlands. Furthermore, model predictions tended to be less accurate for stations located in rough terrain and deep valleys.
11
Jonsson, Stig. "Synoptic forcing of wind and temperature in a large cirque 300 km from the coast of East Antarctica." Antarctic Science 7, no. 4 (December 1995): 409–20. http://dx.doi.org/10.1017/s0954102095000575.
Full textAbstract:
Between 18 January 1988 and 3 June 1989, an automatic weather station recorded 13 different weather parameters every 3 h on a blue-ice area located in Scharffenbergbotnen, a large cirque in central Heimefrontfjella 300 km from the Weddell Sea coast. The first part of the paper reports on annual and monthly data regarding air temperature, air pressure, wind speed and wind direction, and a comparison is also made with corresponding data from the Neumayer and Halley stations. The second part deals mainly with winter (i.e. April–September) conditions in Scharffenbergbotnen. They seem, at least during 1988–89, to have been characterized by a large-scale (30–40 days) and, superimposed on the large-scale, a small-scale (3–4 days) co-variation of air temperature, air pressure and wind speed. The large-scale variation was earlier found to be synoptically forced. This paper shows that synoptic forcing exists also on smaller time scales. Pools of cold, stagnant air are regularly formed in the cirque only to be blown away by katabatic winds triggered by small variations in the synoptic pressure field. When this happens the air temperature increases by more than 20°C and the wind direction swings from east towards south-east. When low pressures dominate in the eastern part of the Weddell Sea, the katabatic winds become very strong, but weaker wind pulses also take place when the synoptic pressure gradient is directed towards the north-east. It therefore seems as if these very regular katabatic events are forced both by synoptic-scale pressure gradients and gradients due to the sloped inversion.
12
Muita, Richard, Paul Kucera, Stella Aura, David Muchemi, David Gikungu, Samuel Mwangi, Martin Steinson, et al. "Towards Increasing Data Availability for Meteorological Services: Inter-Comparison of Meteorological Data from a Synoptic Weather Station and Two Automatic Weather Stations in Kenya." American Journal of Climate Change 10, no. 03 (2021): 300–316. http://dx.doi.org/10.4236/ajcc.2021.103014.
Full text
13
Massart, S., A. Agustí-Panareda, J. Heymann, M. Buchwitz, F. Chevallier, M. Reuter, M. Hilker, et al. "Ability of the 4-D-Var analysis of the GOSAT BESD XCO<sub>2</sub> retrievals to characterize atmospheric CO<sub>2</sub> at large and synoptic scales." Atmospheric Chemistry and Physics Discussions 15, no. 18 (September 28, 2015): 26273–313. http://dx.doi.org/10.5194/acpd-15-26273-2015.
Full textAbstract:
Abstract. This study presents results from the European Centre for Medium-Range Weather Forecasts (ECMWF) carbon dioxide (CO2) analysis system where the atmospheric CO2 is controlled through the assimilation of column-average dry-air mole fractions of CO2 (XCO2) from the Greenhouse gases Observing Satellite (GOSAT). The analysis is compared to a free run simulation and they are both evaluated against XCO2 data from the Total Carbon Column Observing Network (TCCON). We show that the assimilation of the GOSAT XCO2 product from the Bremen Optimal Estimation DOAS (BESD) algorithm during the year 2013 provides XCO2 fields with an improved station-to-station bias deviation of 0.7 parts per million (ppm) compared to the free run (1.4 ppm) and an improved estimated precision of ~ 1 ppm compared to the used GOSAT data (3.4 ppm). We also show that the analysis has skill for synoptic situations in the vicinity of frontal systems where the GOSAT retrievals are sparse due to cloud contamination. We finally computed the 10 day forecast from each analysis at 00:00 UTC. Compared to its own analysis the CO2 forecast shows synoptic skill for the largest scale weather patterns even up to day 5 according to the anomaly correlation coefficient.
14
Risius, S., H. Xu, F. Di Lorenzo, H. Xi, H. Siebert, R. A. Shaw, and E. Bodenschatz. "Schneefernerhaus as a mountain research station for clouds and turbulence." Atmospheric Measurement Techniques 8, no. 8 (August 13, 2015): 3209–18. http://dx.doi.org/10.5194/amt-8-3209-2015.
Full textAbstract:
Abstract. Cloud measurements are usually carried out with airborne campaigns, which are expensive and are limited by temporal duration and weather conditions. Ground-based measurements at high-altitude research stations therefore play a complementary role in cloud study. Using the meteorological data (wind speed, direction, temperature, humidity, visibility, etc.) collected by the German Weather Service (DWD) from 2000 to 2012 and turbulence measurements recorded by multiple ultrasonic sensors (sampled at 10 Hz) in 2010, we show that the Umweltforschungsstation Schneefernerhaus (UFS) located just below the peak of Zugspitze in the German Alps, at a height of 2650 m, is a well-suited station for cloud–turbulence research. The wind at UFS is dominantly in the east–west direction and nearly horizontal. During the summertime (July and August) the UFS is immersed in warm clouds about 25 % of the time. The clouds are either from convection originating in the valley in the east, or associated with synoptic-scale weather systems typically advected from the west. Air turbulence, as measured from the second- and third-order velocity structure functions that exhibit well-developed inertial ranges, possesses Taylor microscale Reynolds numbers up to 104, with the most probable value at ~ 3000. In spite of the complex topography, the turbulence appears to be nearly as isotropic as many laboratory flows when evaluated on the "Lumley triangle".
15
Massart, Sébastien, Anna Agustí-Panareda, Jens Heymann, Michael Buchwitz, Frédéric Chevallier, Maximilian Reuter, Michael Hilker, et al. "Ability of the 4-D-Var analysis of the GOSAT BESD XCO<sub>2</sub> retrievals to characterize atmospheric CO<sub>2</sub> at large and synoptic scales." Atmospheric Chemistry and Physics 16, no. 3 (February 12, 2016): 1653–71. http://dx.doi.org/10.5194/acp-16-1653-2016.
Full textAbstract:
Abstract. This study presents results from the European Centre for Medium-Range Weather Forecasts (ECMWF) carbon dioxide (CO2) analysis system where the atmospheric CO2 is controlled through the assimilation of column-averaged dry-air mole fractions of CO2 (XCO2) from the Greenhouse gases Observing Satellite (GOSAT). The analysis is compared to a free-run simulation (without assimilation of XCO2), and they are both evaluated against XCO2 data from the Total Carbon Column Observing Network (TCCON). We show that the assimilation of the GOSAT XCO2 product from the Bremen Optimal Estimation Differential Optical Absorption Spectroscopy (BESD) algorithm during the year 2013 provides XCO2 fields with an improved mean absolute error of 0.6 parts per million (ppm) and an improved station-to-station bias deviation of 0.7 ppm compared to the free run (1.1 and 1.4 ppm, respectively) and an improved estimated precision of 1 ppm compared to the GOSAT BESD data (3.3 ppm). We also show that the analysis has skill for synoptic situations in the vicinity of frontal systems, where the GOSAT retrievals are sparse due to cloud contamination. We finally computed the 10-day forecast from each analysis at 00:00 UTC, and we demonstrate that the CO2 forecast shows synoptic skill for the largest-scale weather patterns (of the order of 1000 km) even up to day 5 compared to its own analysis.
16
Brigode, P., Z. Mićović, P. Bernardara, E. Paquet, F. Garavaglia, J. Gailhard, and P. Ribstein. "Linking ENSO and heavy rainfall events over coastal British Columbia through a weather pattern classification." Hydrology and Earth System Sciences 17, no. 4 (April 17, 2013): 1455–73. http://dx.doi.org/10.5194/hess-17-1455-2013.
Full textAbstract:
Abstract. Classifications of atmospheric weather patterns (WPs) are widely used for the description of the climate of a given region and are employed for many applications, such as weather forecasting, downscaling of global circulation model outputs and reconstruction of past climates. WP classifications were recently used to improve the statistical characterisation of heavy rainfall. In this context, bottom-up approaches, combining spatial distribution of heavy rainfall observations and geopotential height fields have been used to define WP classifications relevant for heavy rainfall statistical analysis. The definition of WPs at the synoptic scale creates an interesting variable which could be used as a link between the global scale of climate signals and the local scale of precipitation station measurements. We introduce here a new WP classification centred on the British Columbia (BC) coastal region (Canada) and based on a bottom-up approach. Five contrasted WPs composed this classification, four rainy WPs and one non-rainy WP, the anticyclonic pattern. The four rainy WPs are mainly observed in the winter months (October to March), which is the period of heavy precipitation events in coastal BC and is thus consistent with the local climatology. The combination of this WP classification with the seasonal description of rainfall is shown to be useful for splitting observed precipitation series into more homogeneous sub-samples (i.e. sub-samples constituted by days having similar atmospheric circulation patterns) and thus identifying, for each station, the synoptic situations that generate the highest hazard in terms of heavy rainfall events. El Niño-Southern Oscillations (ENSO) significantly influence the frequency of occurrence of two coastal BC WPs. Within each WP, ENSO seem to influence only the frequency of rainy events and not the magnitudes of heavy rainfall events. Consequently, heavy rainfall estimations do not show significant evolution of heavy rainfall behaviour between Niño and Niña winters. However, the WP approach captures the variability of the probability of occurrences of synoptic situations generating heavy rainfall depending on ENSO and opening interesting perspectives for the analysis of heavy rainfall distribution in a non-stationary context.
17
Brigode, P., Z. Mićović, P. Bernardara, E. Paquet, F. Garavaglia, J. Gailhard, and P. Ribstein. "Linking ENSO and heavy rainfall events over Coastal British Columbia through a weather pattern classification." Hydrology and Earth System Sciences Discussions 9, no. 10 (October 15, 2012): 11733–68. http://dx.doi.org/10.5194/hessd-9-11733-2012.
Full textAbstract:
Abstract. Classifications of atmospheric weather patterns (WPs) are widely used for the description of the climate of a given region and are employed for many applications, such as weather forecasting, downscaling of global circulation model outputs and reconstruction of past climates. WP classifications were recently used to improve the statistical characterisation of heavy rainfall. In this context, bottom-up approaches, combining spatial distribution of heavy rainfall observations and geopotential height fields have been used to define WP classifications relevant for heavy rainfall statistical analysis. The definition of WPs at the synoptic scale creates an interesting variable which could be used as a link between the global scale of climate signals and the local scale of precipitation station measurements. We introduce here a new WP classification centred on the British Columbia Coastal region (Canada) and based on a bottom-up approach. Five contrasted WPs composed this classification, four rainy WPs and one non-rainy WP, the anticyclonic pattern. The four rainy WPs are mainly observed in the winter months (October to March), which is the period of heavy precipitation events in Coastal BC and is thus consistent with the local climatology. The combination of this WP classification with the seasonal description of rainfall is shown to be useful for splitting observed precipitation series into more homogeneous sub-samples and thus identifying, for each station, the synoptic situations that generate the highest hazard in terms of heavy rainfall events. El Niño Southern Oscillations significantly influence the frequency of occurrence of two Coastal BC WPs. Within each WP, ENSO seem to influence only the frequency of rainy events and not the magnitudes of heavy rainfall events. Consequently, MEWP heavy rainfall estimations do not show significant evolution of heavy rainfall behaviour between Niño and Niña winters. However, the WP approach captures the variability of the probability of occurrences of synoptic situations generating heavy rainfall depending on ENSO and opening interesting perspectives for the analysis of heavy rainfall distribution in a non-stationary context.
18
Carrega, P. "Instantaneous and Automatic Identification of Weather Types for a Forest Fire Decision Support System." International Journal of Wildland Fire 7, no. 3 (1997): 265. http://dx.doi.org/10.1071/wf9970265.
Full textAbstract:
The objective of this study, carried out as part of a European Union Contract, was to elaborate an aid package that enables automatic and 'real time' identification of the instantaneous weather situation during seasons with high forest fire hazards. The weather types are defined on the basis of discrimination between the breeze and synoptic wind regimes established from a network of 21 automatic sensors installed in the southeastern extremity of France. The establishment of rules such as: if at station X the wind is from a direction of 100-140° and blows at 2 to 5 m/s; and if, etc..., then the situation is such — enables, in a logic of artificial intelligence, the proposal of a 'symbolical', 'analog' model of the weather behaviours to be expected over a given area.
19
Osipov, Eduard Y., and Olga P. Osipova. "Moisture sources and synoptic conditions of summer precipitation in the glacial zone of the East Sayan Range." Advances in Science and Research 17 (March 24, 2020): 1–8. http://dx.doi.org/10.5194/asr-17-1-2020.
Full textAbstract:
Abstract. Precipitation in high-mountain regions is characterized by a strong heterogeneity due to complex interaction between atmospheric circulation and steep topography, however, extremely rare network of high elevation stations hampers the adequate high resolution regional climate modeling. In this study we present new data of precipitation directly measured in high-mountain catchment, on the continental glacier (East Sayan Range, south of East Siberia) during the summer periods of 2015–2017 using automatic weather station. The precipitation record was compared with near located weather stations and ERA Interim and NCEP/NCAR reanalysis data. Precipitation mode similar to the glacier site was found at the stations located west and northwest, while ERA Interim and NCEP/NCAR reanalysis data underestimated the precipitation by 40 % and 70 %, respectively. Atmospheric circulation patterns in days with precipitation were analyzed by using mean sea level pressure, geopotential height at 700 and 500 hPa and classification of macro scale atmospheric processes of the Northern Hemisphere by Dzerdzeevskii. Summer precipitation was mostly associated with meridional southern group of large scale circulation the Northern Hemisphere, while at synoptic scale it basically fell in cyclonic (49 % of precipitation) and low-gradient cyclonic (30 %) baric fields. Six typical atmospheric circulation patterns over the East Sayan were identified for days with precipitation. The sources and atmospheric moisture transfer to the glacier was defined by using the HYSPLIT trajectory model. The most of summer precipitation (70 %) was related with western cyclones, while about 25 % of rainfalls (mainly of moderate to strong intensity) was originated from the south-east (Pacific monsoon influence).
20
Gulev, Sergey K., Olga Zolina, and Youri Reva. "Synoptic and subsynoptic variability in the North Atlantic as revealed by the Ocean Weather Station data." Tellus A 52, no. 3 (May 2000): 323–29. http://dx.doi.org/10.1034/j.1600-0870.2000.d01-6.x.
Full text
21
Gulev, Sergey K., Olga Zolina, and Youri Reva. "Synoptic and subsynoptic variability in the North Atlantic as revealed by the Ocean Weather Station data." Tellus A: Dynamic Meteorology and Oceanography 52, no. 3 (January 2000): 323–29. http://dx.doi.org/10.3402/tellusa.v52i3.12268.
Full text
22
Risius, S., H. Xu, F. Di Lorenzo, H. Xi, H. Siebert, R. A. Shaw, and E. Bodenschatz. "Schneefernerhaus as a mountain research station for clouds and turbulence – Part 1: Flow conditions and large-scale turbulence." Atmospheric Measurement Techniques Discussions 8, no. 1 (January 15, 2015): 541–68. http://dx.doi.org/10.5194/amtd-8-541-2015.
Full textAbstract:
Abstract. Cloud measurements are usually carried out with airborne campaigns, which are expensive and are limited by temporal duration and weather conditions. Ground based measurements at high-altitude research stations therefore play a complementary role in cloud study. Using the meteorological data (wind speed, direction, temperature, humidity, visibility, etc.) collected by the German Weather Service (DWD) from 2000 to 2012 and turbulence measurements recorded by multiple ultrasonic sensors (sampled at 10 Hz) in 2010, we show that the Umweltforschungsstation Schneefernerhaus (UFS) located just below the peak of Zugspitze in the German Alps, at a height of 2650 m, is a well-suited station for cloud-turbulence research. The wind at UFS is dominantly in the east–west direction and nearly horizontal. During the summer time (July and August) the UFS is immersed in warm clouds about 25% of the time. The clouds are either from convection originating in the valley in the east, or associated with synoptic-scale weather systems typically advected from the west. Air turbulence, as measured from the second and third order velocity structure functions that exhibit well-developed inertial ranges, possesses Taylor microscale Reynolds numbers up to 104, with the most probable value at ~ 3000. In spite of the complex topography, the turbulence appears to be nearly as isotropic as many laboratory flows when evaluated on the so called "Lumley-triangle".
23
Fragoso, M., R. M. Trigo, J. G. Pinto, S. Lopes, A. Lopes, S. Ulbrich, and C. Magro. "The 20 February 2010 Madeira flash-floods: synoptic analysis and extreme rainfall assessment." Natural Hazards and Earth System Sciences 12, no. 3 (March 23, 2012): 715–30. http://dx.doi.org/10.5194/nhess-12-715-2012.
Full textAbstract:
Abstract. This study aims to characterise the rainfall exceptionality and the meteorological context of the 20 February 2010 flash-floods in Madeira (Portugal). Daily and hourly precipitation records from the available rain-gauge station networks are evaluated in order to reconstitute the temporal evolution of the rainstorm, as its geographic incidence, contributing to understand the flash-flood dynamics and the type and spatial distribution of the associated impacts. The exceptionality of the rainstorm is further confirmed by the return period associated with the daily precipitation registered at the two long-term record stations, with 146.9 mm observed in the city of Funchal and 333.8 mm on the mountain top, corresponding to an estimated return period of approximately 290 yr and 90 yr, respectively. Furthermore, the synoptic associated situation responsible for the flash-floods is analysed using different sources of information, e.g., weather charts, reanalysis data, Meteosat images and radiosounding data, with the focus on two main issues: (1) the dynamical conditions that promoted such anomalous humidity availability over the Madeira region on 20 February 2010 and (2) the uplift mechanism that induced deep convection activity.
24
Grimalt-Gelabert, Miquel, Gabriel Alomar-Garau, and Javier Martin-Vide. "Synoptic Causes of Torrential Rainfall in the Balearic Islands (1941–2010)." Atmosphere 12, no. 8 (August 13, 2021): 1035. http://dx.doi.org/10.3390/atmos12081035.
Full textAbstract:
This article determines the atmospheric situation for the 53 days where any weather station in the Balearic Islands detected torrential rain (equal to or above 200 mm in a single day) during the period 1941–2010. To do this, the synoptic charts for each day were analysed, classifying them in accordance with the types established by Martín Vide (1984) and, in addition, through the automatic synoptic classifications from Jenkinson and Collison (1977). The analysis results demonstrate the importance of cyclonic situations over the Western Mediterranean Basin linked to favourable altitude configurations (earlier presence of cut-off lows—DANA—or troughs). These atmospheric conditions contrast with those that predominate in nearby Mediterranean areas, such as the south-eastern coast of the Iberian Peninsula. Days with torrential rain on the Iberian coastline tend to coincide with easterly advections—a less common occurrence in the Balearics.
25
Fox-Hughes, Paul, Ian Barnes-Keoghan, and Adrian Porter. "Observations of a tornado at an Automatic Weather Station in northern Tasmania." Journal of Southern Hemisphere Earth Systems Science 68, no. 1 (2018): 215. http://dx.doi.org/10.1071/es18012.
Full textAbstract:
On 15 April 2009, the Automatic Weather Station (AWS) at Scottsdale, in north-eastern Tasmania, recorded a wind gust of 54 ms-1 (194 kmh-1) as an active squall line crossed the state. Investigation of the environment, instrumentation, and damage resulted in the conclusion that this was a genuine wind gust caused by a tornado passing very close to the anemometer. This was the first direct AWS observation of a tornado in Australia, and one of very few such observations in the world. In this report, we document the weather event which produced the tornado, briefly outline the synoptic situation leading to its occurrence, document additional background observations that provide context for the event, and discuss the nature of the observations made by the AWS and the method by which the wind gust observations were verified.The squall line was part of a cold front that crossed northern Tasmania on the morning of 15 April 2009. At 300 hPa, the orientation of the short-wave trough associated with the cold front changed from positively to strongly negatively tilted as it moved over central Victoria and Tasmania. The orientation of the trough and position of a jet streak within it suggested strong upper divergence and strong vertical motion. These contributed to thunderstorm development and resulted in very substantial vertical wind shear through the lower half of the troposphere, which in turn contributed to the organisation of the severe convection. Near the surface, low cloud base and strong vertical windshear in the lowest kilometre provided conditions conducive to tornado development.
26
Stoev, Krasimir, and Guergana Guerova. "Foehn classification and climatology in Sofia for 1975–2014." Időjárás 124, no. 4 (2020): 483–97. http://dx.doi.org/10.28974/idojaras.2020.4.4.
Full textAbstract:
Foehn is a warm, dry, and downslope wind blowing in the lee side of a mountain range. It is a well known example of a local atmospheric circulation. The foehn wind is also an extreme weather event, and its forecasting is an important task for the short-range weather forecaster. The foehn in Bulgaria is observed on the northern slopes of the mountains, as a result of warm air advection from the south and southwest. Its occurrence is highest north of the Vitosha and Balkan mountains. In this study, a synoptic classification of the meteorological conditions leading to foehn in the central meteorological station in Sofia for the period 1975–2014 is made. Foehn climatology is prepared, and in addition, an evaluation of the foehn as an extreme weather event by wind gust is presented. For the period 1975–2014, there were 298 days with foehn in Sofia, which resulted from 220 synoptic cases. A manual foehn classification was developed with four major types. Type I is associated with the Mediterranean cyclone with the highest frequency – 52% of the foehn days. Foehn climatology gives average annual number of 7.5 foehn days but with a large variance between decades. The lowest annual number of days (4.5) is registered for the 2005–2014 period, and it was associated with the lowest recorded wind gust (22 m/s).
27
Weber, Nicholas J., Matthew A. Lazzara, Linda M. Keller, and John J. Cassano. "The Extreme Wind Events in the Ross Island Region of Antarctica." Weather and Forecasting 31, no. 3 (June 1, 2016): 985–1000. http://dx.doi.org/10.1175/waf-d-15-0125.1.
Full textAbstract:
Abstract Numerous incidents of structural damage at the U.S. Antarctic Program’s (USAP) McMurdo Station due to extreme wind events (EWEs) have been reported over the past decade. Utilizing nearly 20 yr (~1992–2013) of University of Wisconsin automatic weather station (AWS) data from three different stations in the Ross Island region (Pegasus North, Pegasus South, and Willie Field), statistical analysis shows no significant trends in EWE frequency, intensity, or duration. EWEs more frequently occur during the transition seasons. To assess the dynamical environment of these EWEs, Antarctic Mesoscale Prediction System (AMPS) forecast back trajectories are computed and analyzed in conjunction with several other AMPS fields for the strongest events at McMurdo Station. The synoptic analysis reveals that McMurdo Station EWEs are nearly always associated with strong southerly flow due to an approaching Ross Sea cyclone and an upper-level trough around Cape Adare. A Ross Ice Shelf air stream (RAS) environment is created with enhanced barrier winds along the Transantarctic Mountains, downslope winds in the lee of the glaciers and local topography, and a tip jet effect around Ross Island. The position and intensity of these Ross Sea cyclones are most influenced by the occurrence of a central Pacific ENSO event, which causes the upper-level trough to move westward. An approaching surface cyclone would then be in position to trigger an event, depending on how the wind direction and speed impinges on the complex topography around McMurdo Station.
28
Dunn, R. J. H., K. M. Willett, P. W. Thorne, E. V. Woolley, I. Durre, A. Dai, D. E. Parker, and R. S. Vose. "HadISD: a quality controlled global synoptic report database for selected variables at long-term stations from 1973–2010." Climate of the Past Discussions 8, no. 3 (May 21, 2012): 1763–833. http://dx.doi.org/10.5194/cpd-8-1763-2012.
Full textAbstract:
Abstract. This paper describes the creation of HadISD; an automatically quality-controlled synoptic resolution dataset of temperature, dewpoint temperature, sea-level pressure, wind speed, wind direction and cloud cover from global weather stations for 1973–2010. The full dataset consists of over 6000 stations, with 3375 long-term stations deemed to have sufficient sampling and quality for climate applications requiring sub-daily resolution. As with other surface datasets, coverage is heavily skewed towards Northern Hemisphere mid-latitudes. The dataset is constructed from a large pre-existing ASCII flatfile data bank that represents over a decade of substantial effort at data retrieval, reformatting and provision. The work proceeded in several steps: merging stations with multiple reporting identifiers; reformatting to netcdf; quality control; and then filtering to form a final dataset. Particular attention has been paid to maintaining true extreme values where possible within an automated objective process. Detailed validation has been performed on a subset of global stations and also on UK data using known extreme events to help finalise the QC tests. Further validation was performed on a selection of extreme events world-wide (Hurricane Katrina in 2005, the cold snap in Alaska in 1989 and heat waves in SE Australia in 2009). Some very initial analyses are performed to illustrate some of the types of problems to which the final data could be applied. Although the filtering has removed the poorest station records, no attempt has been made to homogenise the data thus far, due to the complexity of retaining the true distribution of high-resolution data when applying adjustments. Hence non-climatic, time-varying errors may still exist in many of the individual station records and care is needed in inferring long-term trends from these data. This dataset will allow the study of high frequency variations of temperature, pressure and humidity on a global basis over the last four decades. Both individual extremes and the overall population of extreme events could be investigated in detail to allow for comparison with past and projected climate.
29
Przybylak, Rajmund, and Rafał Maszewski. "Influence of Atmospheric Circulation on Air Temperature and Precipitation in the Bydgoszcz–Toruń Region in the Period from 1921 to 2000." Bulletin of Geography. Physical Geography Series 1, no. 1 (June 1, 2009): 19–37. http://dx.doi.org/10.2478/bgeo-2009-0002.
Full textAbstract:
Abstract The following article presents the results of research on the influence of atmospheric circulation on air temperature and atmospheric precipitation in the Bydgoszcz-Toruń region (Poland) in the period 1921-2000. In order to do this, we have constructed a daily calendar of synoptic situations using criteria proposed by Niedźwiedź (1981). Daily values of air temperature and atmospheric precipitation were collected from the meteorological station in Toruń. Research results show that weather conditions in the study area are influenced predominantly by the direction of air mass advection and, to a lesser extent, by the prevailing type of isobaric system.
30
Pereira, E. B., A. W. Setzer, and I. F. A. Cavalcanti. "222Rn in the Antarctic Peninsula During 1986." Radiation Protection Dosimetry 24, no. 1-4 (August 1, 1988): 85–88. http://dx.doi.org/10.1093/oxfordjournals.rpd.a080247.
Full textAbstract:
Abstract 222Rn was continuously measured at the Brazilian Antarctic Station (62 oS, 58 oW) during the year of 1986. Baseline radon concentration averaged 0.02 Bq.m-3 with surges peaking at 0.4 Bq.m-3. The data exhibited a characteristic periodicity of about 25 days and a strong positive association with short term fluctuations of atmospheric temperature. No seasonal variation of radon were observed. Interpretation of the radon surges with reference to synoptic charts and weather satellite pictures showed that the continental influence of radon at the Antarctic Peninsula is very small and comes only from the tip of the South American cone.
31
Lüdecke, Cornelia. "Neumayer’s impact on meteorology in Germany." Proceedings of the Royal Society of Victoria 123, no. 1 (2011): 35. http://dx.doi.org/10.1071/rs11035.
Full textAbstract:
When Georg von Neumayer (1826–1909) had a practical training with Johann von Lamont (1805-1879) at the observatory at Bogenhausen (today part of Munich), he learnt not only about astronomical observations and the construction of instruments, but also about magnetic and meteorological measurements, as well as the organisation of networks of stations and the importance of publication of measured data and their analysis. When he became first Director of the Deutsche Seewarte (German Maritime Observatory) in Hamburg (1876–1903) he subsequently introduced weather telegraphy and synoptic meteorology and installed a workshop for the development and calibration of meteorological and magnetic instruments and compasses. He also initiated the establishment of a weather service in Bavaria and the aerological (kite) station at Groß Borstel close to Hamburg (1903). Under his guidance the Deutsche Seewarte soon took over a leading role in Germany, which was confirmed in Neumayer’s membership in the International Meteorological Committee (1879–1888). Finally he became the founding President of the Deutsche Meteorologische Gesellschaft (German Meteorological Society) in 1883. This can be regarded as a further important step for the institutionalisation of meteorology as a discipline in Germany.
32
Planchon, O., H. Quénol, N. Dupont, and S. Corgne. "Application of the Hess-Brezowsky classification to the identification of weather patterns causing heavy winter rainfall in Brittany (France)." Natural Hazards and Earth System Sciences 9, no. 4 (July 17, 2009): 1161–73. http://dx.doi.org/10.5194/nhess-9-1161-2009.
Full textAbstract:
Abstract. An accurate knowledge of the weather patterns causing winter rainfall over the Scorff watershed in western Brittany (W. France) was developed prior to studies of the impact of the climate factor on land use management, and of the hydrological reponses to rain-producing weather patterns. These two studies are carried out in the context of the climate change. The identification of rainy air-circulation types was realized using the objective computational version of the 29-type Hess and Brezowsky Grosswetterlagen system of classifying European synoptic regimes, for the cold season (November-March) of the 1958–2005 period at the reference weather station of Lorient, and 13 other stations located in western and southern Brittany, including a more detailed study for the wet 2000–2001 cold season for three reference stations of the Scorff watershed (Lorient, Plouay and Plouray). The precipitation proportion (including the days with rainfall ≥20 mm) was calculated by major air-circulation type (GWT: see Appendix A) and by individual air-circulation subtype (GWL: see Appendix A) for the studied time-period. The most frequently occurrence of rainy days associated with westerly and southerly GWL confirmed well-known observations in western Europe and so justify the use of the Hess-Brezowsky classification in other areas outside Central Europe. The southern or south-western exposure of the watershed with a hilly inland area enhanced the heavy rainfall generated by the SW and S circulation types, and increased the difference between the rainfall amounts of coastal and inland stations during the wettest days.
33
Oltmanns, Marilena, Fiammetta Straneo, and Marco Tedesco. "Increased Greenland melt triggered by large-scale, year-round cyclonic moisture intrusions." Cryosphere 13, no. 3 (March 7, 2019): 815–25. http://dx.doi.org/10.5194/tc-13-815-2019.
Full textAbstract:
Abstract. Surface melting is a major driver of Greenland's mass loss. Yet, the mechanisms that trigger melt are still insufficiently understood because seasonally based studies blend processes initiating melt with positive feedbacks. Here, we focus on the triggers of melt by examining the synoptic atmospheric conditions associated with 313 rapid melt increases, detected in a satellite-derived melt extent product, equally distributed throughout the year over the period 1979–2012. By combining reanalysis and weather station data, we show that melt is initiated by a cyclone-driven, southerly flow of warm, moist air, which gives rise to large-scale precipitation. A decomposition of the synoptic atmospheric variability over Greenland suggests that the identified, melt-triggering weather pattern accounts for ∼40 % of the net precipitation, but increases in the frequency, duration and areal extent of the initiated melting have shifted the line between mass gain and mass loss as more melt and rainwater run off or accumulate in the snowpack. Using a regional climate model, we estimate that the initiated melting more than doubled over the investigated period, amounting to ∼28 % of the overall surface melt and revealing that, despite the involved mass gain, year-round precipitation events are participating in the ice sheet's decline.
34
Palomino, I., and F. Martín. "A Simple Method for Spatial Interpolation of the Wind in Complex Terrain." Journal of Applied Meteorology 34, no. 7 (July 1, 1995): 1678–93. http://dx.doi.org/10.1175/1520-0450-34.7.1678.
Full textAbstract:
Abstract The topographical elevation difference is proposed as a new variable for spatial interpolation of the sparse surface wind measurements to a finer mesh in a complex terrain area. The most used method for the initialization of diagnostic wind field models is based on the inverse-distance-squared weighted averaging interpolation technique regardless of the topographical elevation. Analysis of experimental data obtained from six meteorological towers deployed at several heights on the slopes along a valley in the South of Spain has shown a good correlation between wind speed and elevation above valley bottom. The efficiency of the inverse absolute elevation difference and the inverse distance squared as averaging weights for interpolation of the wind vector at several locations is checked; this is done for two meteorological synoptic weather types: strong synoptic winds, and thermal low over the Iberian Peninsula. For the latter weather type, the formation of nocturnal thermal inversion and the drainage flows are taken into account. Wind fields in the valley resulting from the two interpolation methods are compared. The elevation difference between meteorological station and grid point seems to be an important variable to be included in the wind field initialization process, that is, interpolation of the wind vector to a grid, when complex terrain areas are considered.
35
Adolphs, Ute, and Gerd Wendler. "A pilot study on the interactions between katabatic winds and polynyas at the Adélie Coast, eastern Antarctica." Antarctic Science 7, no. 3 (September 1995): 307–14. http://dx.doi.org/10.1017/s0954102095000423.
Full textAbstract:
Infrared satellite images of the coastal area off Adélie Land were examined together with two wind data sets, one from the manned French station, Dumont d'Urville, the other one from an Automatic Weather Station (AWS) during the 1986 austral winter. A correlation between the development of open water areas (polynyas) and the appearance of extremely strong offshore winds can be drawn. The wind direction tended to be more perpendicular to the coastline during these extreme ‘events’, suggesting a katabatic origin of the increase in wind strength. In the study area the influence of the katabatic wind on the sea ice extends 20–100 km offshore. Sea ice motion further off the coast seems to be more dominated by synoptic scale weather systems. Broader scale atmospheric influences may create large polynya structures which influence the development of coastal winds, as the temperature contrast between open water and the cold continent generates its own circulation. Strong wind events can have a weakening effect on the coastal sea ice which can lead to a much more sensitive reaction of the sea ice in response to following anomalous wind events.
36
Schuhmacher, P. "Windfelduntersuchung in Zürich : Ergebnisse von Messungen und numerischen Modellierungen." Geographica Helvetica 46, no. 1 (March 31, 1991): 4–10. http://dx.doi.org/10.5194/gh-46-4-1991.
Full textAbstract:
Abstract. From 1985 to 1989 the Department of Geography of the ETH in Zürich carried out a project called "Stadtklima Zürich". Following a brief description of the project the paper is centered on theoretical and experimental studies concerning the air-flow above Zürich. The wind measurements were undertaken with a network of about 20 stations. The interpretation of these measurements was concentrated on important weather types. Apart from a cartographie representation of the measured data, a diagnostic model (DIAMO) was used for the data interpolation. A non-hydrostatic numerical model (MONARC) helped to interprete dynamicalm processes over complex topography. With an example of a Situation with easterly synoptic wind the measured windfield is compared with the simulations which show a fairly good correspondence. Measurements over the railroad tracks near the Central Station show the transition from mesoscale topographic to microscale or urban building effects. By using a particle trajectory model (LADI and TRAMO), the problem of air pollution dispersion over the complex urban topography is discussed.
37
Luo, Yali, Mengwen Wu, Fumin Ren, Jian Li, and Wai-Kin Wong. "Synoptic Situations of Extreme Hourly Precipitation over China." Journal of Climate 29, no. 24 (November 21, 2016): 8703–19. http://dx.doi.org/10.1175/jcli-d-16-0057.1.
Full textAbstract:
Abstract In this study, synoptic situations associated with extreme hourly precipitation over China are investigated using rain gauge data, weather maps, and composite radar reflectivity data. Seasonal variations of hourly precipitation (>0.1 mm h−1) suggest complicated regional features in the occurrence frequency and intensity of rainfall. The 99.9th percentile is thus used as the threshold to define the extreme hourly rainfall for each station. The extreme rainfall is the most intense over the south coastal areas and the North China Plain. About 77% of the extreme rainfall records occur in summer with a peak in July (30.4%) during 1981–2013. Nearly 5800 extreme hourly rainfall records in 2011–15 are classified into four types according to the synoptic situations under which they occur: the tropical cyclone (TC), surface front, vortex/shear line, and weak-synoptic forcing. They contribute 8.0%, 13.9%, 39.1%, and 39.0%, respectively, to the total occurrence and present distinctive characteristics in regional distribution and seasonal or diurnal variations. The TC type occurs most frequently along the coasts and decreases progressively toward inland China; the frontal type is distributed relatively evenly east of 104°E; the vortex/shear line type shows a prominent center over the Sichuan basin with two high-frequency bands extending from the center southeastward and northeastward, respectively; and the weak-synoptic type occurs more frequently in southeast, southwest, and northern China, and in the easternmost area of northeast China. Occurrences of the weak-synoptic type have comparable contributions from mesoscale convective systems and smaller-scale storms with notable differences in their preferred locations.
38
Forte, Roberta, Francesco Berrilli, Daniele Calchetti, Dario Del Moro, Bernhard Fleck, Cynthia Giebink, William Giebink, et al. "Data reduction pipeline for MOF-based synoptic telescopes." Journal of Space Weather and Space Climate 10 (2020): 63. http://dx.doi.org/10.1051/swsc/2020065.
Full textAbstract:
There are strong scientific cases and practical reasons for building ground-based solar synoptic telescopes. Some issues, like the study of solar dynamics and the forecasting of solar flares, benefit from the 3D reconstruction of the Sun’s atmosphere and magnetic field. Others, like the monitoring and prediction of space weather, require full disk observations, at the proper sampling rate, combining H-alpha images and Doppler velocity and magnetic field. The synoptic telescopes based on Magneto Optical Filters (MOF) using different lines are capable of measuring the line-of-sight Doppler velocity and magnetic field over the full solar disk at different ranges of height in the Sun’s photosphere and low chromosphere. Instruments like the MOTH (Magneto-Optical filters at Two Heights), using a dual-channel based on MOFs operating at 589.0 nm (Na D2 line) and 769.9 nm (K D1 line), the VAMOS instrument (Velocity And Magnetic Observations of the Sun), operating at 769.9 nm (K D1 line), and the future TSST (Tor Vergata Synoptic Solar Telescope), using a dual-channel telescope operating at 656.28 nm (H-alpha line) and at 769.9 nm (K D1 line), allow to face both aspects, the scientific and the operative related to Space Weather applications. The MOTH, VAMOS and TSST data enable a wide variety of studies of the Sun, from seismic probing of the solar interior (sound speed, rotation, details of the tachocline, sub-surface structure of active regions), to the dynamics and magnetic evolution of the lower part of the solar atmosphere (heating of the solar atmosphere, identification of the signatures of solar eruptive events, atmospheric gravity waves, etc.), to the 3D reconstruction of the solar atmosphere and flare locations. However, the use of MOF filters requires special care in calibrating the data for scientific or operational use. This work presents a systematic pipeline that derives from the decennial use of MOF’s technology. More in detail, the pipeline is based on data reduction procedures tested and validated on MOTH data acquired at Mees Solar Observatory of the University of Hawaii Haleakala Observatories and at South Pole Solar Observatory (SPSO), at the Amundsen-Scott South Pole Station in Antarctica, during Antarctica Summer Campaign 2016/17.
39
Adams, Neil. "Identifying the Characteristics of Strong Southerly Wind Events at Casey Station in East Antarctica Using a Numerical Weather Prediction System." Monthly Weather Review 133, no. 12 (December 1, 2005): 3548–61. http://dx.doi.org/10.1175/mwr3050.1.
Full textAbstract:
Abstract Casey Station in East Antarctica is not often subject to strong southerly flow off the Antarctic continent but when such events occur, operations at the station are often adversely impacted. Not only are the dynamics of such events poorly understood, but the forecasting of such occurrences is difficult. The following study uses model output from a 12-month experiment using the Antarctic Limited-Area Prediction System (ALAPS) to advance the understanding of the dynamics of such events and postulates that what are often described as katabatic wind events are more likely to be synoptic in scale, with mid- and upper-level tropospheric dynamics forcing the surface layer flow. Strong surface layer flows that have a katabatic signature commonly develop on the steep Antarctic escarpment but rarely extend out over the coast in the Casey area, most probably as a result of cold air damming. However, the development of a strong south-southwesterly jet over Casey provides a mechanism whereby the katabatic can move out off the coast.
40
Allison, Ian. "Surface climate of the interior of the Lambert Glacier basin, Antarctica, from automatic weather station data." Annals of Glaciology 27 (1998): 515–20. http://dx.doi.org/10.3189/1998aog27-1-515-520.
Full textAbstract:
Data from six automatic weather stations deployed around the interior of the Lambert Glacier basin, Antarctica, at surface elevations of 1830-2741 m are used to compile a surface climatology of this part of interior Antarctica for the period 1994-96. The stations measure air pressure, near-surface wind speed and air temperature at several levels, wind direction and firn temperatures. The topography of the basin, which extends more than 800 km inland, controls the katabatic wind regime and strongly influences the surface climate of the region. Windiest sites are on the steep coastal slopes, and within the depression of the Lambert and Mellor Ice Streams where the flow is topographically channelled. Surface winds here show greater seasonal variation in speed but less variation in direction than elsewhere. The annual mean temperatures on the relatively steep slopes on the eastern side of the basin are 4-5°C warmer than at equivalent altitude on the western side. During winter, near-synchronous synoptic temperature and pressure increases occur throughout the basin to at least 1000 km from the coast. There is a consistent pattern of diurnal wind variation in the summer at all stations, with maximum wind speed at about 0900 LST (local solar time), and the most easterly direction at 1300 LST.
41
Dunn, R. J. H., K. M. Willett, P. W. Thorne, E. V. Woolley, I. Durre, A. Dai, D. E. Parker, and R. S. Vose. "HadISD: a quality-controlled global synoptic report database for selected variables at long-term stations from 1973–2011." Climate of the Past 8, no. 5 (October 25, 2012): 1649–79. http://dx.doi.org/10.5194/cp-8-1649-2012.
Full textAbstract:
Abstract. This paper describes the creation of HadISD: an automatically quality-controlled synoptic resolution dataset of temperature, dewpoint temperature, sea-level pressure, wind speed, wind direction and cloud cover from global weather stations for 1973–2011. The full dataset consists of over 6000 stations, with 3427 long-term stations deemed to have sufficient sampling and quality for climate applications requiring sub-daily resolution. As with other surface datasets, coverage is heavily skewed towards Northern Hemisphere mid-latitudes. The dataset is constructed from a large pre-existing ASCII flatfile data bank that represents over a decade of substantial effort at data retrieval, reformatting and provision. These raw data have had varying levels of quality control applied to them by individual data providers. The work proceeded in several steps: merging stations with multiple reporting identifiers; reformatting to netCDF; quality control; and then filtering to form a final dataset. Particular attention has been paid to maintaining true extreme values where possible within an automated, objective process. Detailed validation has been performed on a subset of global stations and also on UK data using known extreme events to help finalise the QC tests. Further validation was performed on a selection of extreme events world-wide (Hurricane Katrina in 2005, the cold snap in Alaska in 1989 and heat waves in SE Australia in 2009). Some very initial analyses are performed to illustrate some of the types of problems to which the final data could be applied. Although the filtering has removed the poorest station records, no attempt has been made to homogenise the data thus far, due to the complexity of retaining the true distribution of high-resolution data when applying adjustments. Hence non-climatic, time-varying errors may still exist in many of the individual station records and care is needed in inferring long-term trends from these data. This dataset will allow the study of high frequency variations of temperature, pressure and humidity on a global basis over the last four decades. Both individual extremes and the overall population of extreme events could be investigated in detail to allow for comparison with past and projected climate. A version-control system has been constructed for this dataset to allow for the clear documentation of any updates and corrections in the future.
42
Carrasco, Jorge F., and David H. Bromwich. "A case study of a midtropospheric subsynoptic-scale cyclone that developed over the Ross Sea and Ross Ice Shelf of Antarctica." Antarctic Science 7, no. 2 (June 1995): 199–210. http://dx.doi.org/10.1017/s0954102095000277.
Full textAbstract:
Satellite imagery, synoptic-scale analyses and automatic weather station data were used to study a subsynoptic-scale cyclone that developed over the Ross Sea and Ross Ice Shelf areas of Antarctica. A pre-existing subsynoptic-scale midtropospheric cyclone descended from southern Victoria Land into the semi-permanent baroclinic environment over the south-western corner of the Ross Sea. The subsynoptic-scale cyclone then developed into a frontal system travelling south-eastward over the Ross Ice Shelf and decayed five days later over Marie Byrd Land. It is concluded that stretching of the subsynoptic-scale low, while descending over 2000 m from the high plateau down to sea level, increased its cyclonic vorticity via conservation of potential vorticity. This, along with a cold katabatic outbreak into the northern part of the circulation, provided the mechanisms for its initial development. Subsequently, cold boundary-layer air over the Ross Ice Shelf spiralled into the subsynoptic-scale cyclone supporting its further development. An upper-level synoptic-scale cyclone that approached the area provided the upper-level support for its ESE displacement and development.
43
Pook, Michael J., Peter C. McIntosh, and Gary A. Meyers. "The Synoptic Decomposition of Cool-Season Rainfall in the Southeastern Australian Cropping Region." Journal of Applied Meteorology and Climatology 45, no. 8 (August 1, 2006): 1156–70. http://dx.doi.org/10.1175/jam2394.1.
Full textAbstract:
Abstract Daily rainfall during the April–October growing season in a major cropping region of southeastern Australia has been related to particular types of synoptic weather systems over a period of 33 yr. The analysis reveals that cutoff lows were responsible for at least 50% of all growing-season rainfall and accounted for 80% of daily rainfall events exceeding 25 mm per station. The proportion of rainfall contributed by cutoff lows varies throughout the growing season. It is highest in austral autumn and spring (55% and 57%, respectively) and falls to a minimum in July (42%). By way of contrast, the total contribution of all types of frontal systems to growing-season rainfall is about 32%, although the monthly value reaches a maximum of 41% in July when mean cutoff rainfall reaches a minimum. Rainfall associated with fronts is strongly concentrated in the lower range of daily falls (less than 10 mm per station). Frontal rainfall is found to be more consistent from year to year than is cutoff rainfall. The number of cutoff lows per season is highly variable, and there is a significant correlation between the number of cutoff days and atmospheric blocking in the region south of Australia in each month of the growing season. The mean amount of rainfall per cutoff day is also variable and has declined by approximately 0.8 mm over the analysis period. An understanding of the mechanisms controlling year-to-year variability of cutoff rainfall is therefore an important step in improving seasonal forecasts for agriculture in southeastern Australia.
44
Savvidou, K., S. C. Michaelides, A. Orphanou, P. Constantinides, J. P. Schulz, U. Voigt, and M. Savvides. "Verification of precipitation forecasts by the DWD limited area model LME over Cyprus." Advances in Geosciences 10 (April 26, 2007): 133–38. http://dx.doi.org/10.5194/adgeo-10-133-2007.
Full textAbstract:
Abstract. A comparison is made between the precipitation forecasts by the non-hydrostatic limited area model LME of the German Weather Service (DWD) and observations from a network of rain gauges in Cyprus. This is a first attempt to carry out a preliminary verification and evaluation of the LME precipitation forecasts over the area of Cyprus. For the verification, model forecasts and observations were used covering an eleven month period, from 1/2/2005 till 31/12/2005. The observations were made by three Automatic Weather Observing Systems (AWOS) located at Larnaka and Paphos airports and at Athalassa synoptic station, as well as at 6, 6 and 8 rain gauges within a radius of about 30 km around these stations, respectively. The observations were compared with the model outputs, separately for each of the three forecast days. The "probability of detection" (POD) of a precipitation event and the "false alarm rate" (FAR) were calculated. From the selected cases of the forecast precipitation events, the average forecast precipitation amounts in the area around the three stations were compared with the measured ones. An attempt was also made to evaluate the model's skill in predicting the spatial distribution of precipitation and, in this respect, the geographical position of the maximum forecast precipitation amount was contrasted to the position of the corresponding observed maximum. Maps with monthly precipitation totals observed by a local network of 150 rain gauges were compared with the corresponding forecast precipitation maps.
45
Zebenholzer, Karin, Ernest Rudel, Sophie Frantal, Werner Brannath, Karin Schmidt, Çiçek Wöber-Bingöl, and Christian Wöber. "Migraine and weather: A prospective diary-based analysis." Cephalalgia 31, no. 4 (November 26, 2010): 391–400. http://dx.doi.org/10.1177/0333102410385580.
Full textAbstract:
Aims Weather is mentioned as a trigger factor by migraine patients most frequently. We examined the impact of meteorological factors and the impact of their day-to-day change on the risk of occurrence and persistence of headache and migraine and the correlation of subjective weather perception with objective weather data. Methods We performed a prospective, diary-based cohort study in 238 patients suffering from migraine with or without aura. Patients had to live within 25 km of the Vienna meteorological station and were required to keep a diary for 90 days. We analysed 11 meteorological parameters and 17 synoptic weather situations. For evaluating the hazard of occurrence and persistence of migraine and headache, we performed a univariate and a stepwise multivariate Cox regression analysis. We calculated correlations between subjective weather perception and meteorological data. Results In the uni- and multivariate analysis, a ridge of high pressure increased the risk of headache occurrence, lower mean daily wind speed increased the risk of migraine occurrence and a day-to-day change of daily sunshine duration increased the risk of migraine occurrence. A day-to-day change of the daily minimum temperature decreased the risk of migraine persistence. After correction for multiple testing, none of these findings remained statistically significant. Subjective weather perceptions did not correlate with the occurrence or persistence of migraine or headache. Subjective perception of cold and too-cold weather and of too-warm weather correlated with daily minimum, mean and maximum temperature. Conclusion The influence of weather factors on migraine and headache is small and questionable.
46
Tanimoto, Youichi, Kou Shimoyama, and Shoichi Mori. "Continuous Daily Observation of the Marine Atmospheric Boundary Layer over the Kuroshio by a Helicopter Shuttle Service." Journal of Atmospheric and Oceanic Technology 32, no. 1 (January 2015): 3–21. http://dx.doi.org/10.1175/jtech-d-14-00067.1.
Full textAbstract:
AbstractThis paper describes a new initiative in which in situ observations of the marine atmospheric boundary layer (MABL) are made by a helicopter shuttle connecting six islands south of Tokyo. This observation method aims to make frequent measurements of temperature and moisture in the MABL across an ocean front, where direct measurements of the MABL have been limited. An onboard observation system to meet flight regulations was developed. Observed temperature and moisture as a function of pressure at 1-s intervals provided vertical profiles up to the 900-hPa level above each of the islands, from 24 December 2010 to 6 April 2011, with the exception of an accidental power down in mid-February 2011. The observed values are validated by intercomparison with surface measurements from weather stations, atmospheric soundings, and mesoscale weather analysis provided by the Japan Meteorological Agency. Temperature and moisture values obtained using the system described here at the surface are significantly correlated with those from the weather station. The meridional changes revealed by the observed vertical profiles depict rich MABL structures, such as a cold-air intrusion and a strong near-surface inversion, that are not captured by the mesoscale weather analysis. However, this discrepancy is probably due to insufficient treatment in the mesoscale numerical model rather than observational errors. Additional intercomparisons indicate no influence from either artificial mixing by the helicopter rotor or by dynamic pressure caused by the fast-moving helicopter when obtaining the vertical profiles. Following these validations, the continuation of the initiative will allow for examining the influence of the ocean front on the overlying MABL on a synoptic time scale.
47
Schlosser, Elisabeth, Carleen Reijmer, Hans Oerter, and Wolfgang Graf. "The influence of precipitation origin on the δ18O–T relationship at Neumayer station, Ekstrmisen, Antarctica." Annals of Glaciology 39 (2004): 41–48. http://dx.doi.org/10.3189/172756404781814276.
Full textAbstract:
AbstractThe relationship between δ18O and air temperature at Neumayer station, Ekstrmisen, Antarctica, was investigated using fresh-snow samples from the time period 1981–2000. A trajectory model that calculated 5 day-backward trajectories was used to study the influence of different synoptic weather situations and thus of different moisture sources on this correlation. Generally a high correlation between air temperature and δ18O was found, but the quality of the δ18O–T relationship varied with the different trajectory classes. Additionally, the sea-ice coverage on the travel path of the moist air was considered. The amount of open ocean water underneath the trajectory has a large influence on the δ18O–T relationship. For trajectories that lead completely above open water, no significant correlation between δ18O and T was found, because mixing with air masses containing additionally evaporated water vapour from the ocean influences the isotope ratio of precipitation. A very high correlation, however, was found for transports over the completely ice-covered Weddell Sea.
48
Streten, N. A. "A review of the climate of Mawson – a representative strong wind site in East Antarctica." Antarctic Science 2, no. 1 (March 1990): 79–89. http://dx.doi.org/10.1017/s0954102090000098.
Full textAbstract:
An analysis is made of the climate of the Australian Antarctic station Mawson (67.6°S, 62.9°E) and its hinterland in the light of 30 years of observations and of previous investigations. Data are presented on free atmosphere temperature and wind structure, the synoptic meteorology of the region, solar radiation, surface temperature, sea ice, wind and weather. Emphasis is placed on the characteristics of the shallow south easterly katabatic winds averaging 11.1 m s−1 throughout the year and the frequent periods of intense gale associated with the effects of major Southern Ocean depressions. The climate of Mawson is believed to be typical of much of the coast of East Antarctica in regions where the ice-cap falls steeply to sea level.
49
Mateling, Marian E., Matthew A. Lazzara, Linda M. Keller, George A. Weidner, and John J. Cassano. "Alexander Tall Tower! A Study of the Boundary Layer on the Ross Ice Shelf, Antarctica." Journal of Applied Meteorology and Climatology 57, no. 2 (February 2018): 421–34. http://dx.doi.org/10.1175/jamc-d-17-0017.1.
Full textAbstract:
AbstractBecause of the harsh weather conditions on the Antarctic continent, year-round observations of the low-level boundary layer must be obtained via automated data acquisition systems. Alexander Tall Tower! is an automatic weather station on the Ross Ice Shelf in Antarctica and has been operational since February 2011. At 30 m tall, this station has six levels of instruments to collect environmental data, including temperature, wind speed and direction, relative humidity, and pressure. Data are collected at 30-, 15-, 7.5-, 4-, 2-, and 1-m levels above the snow surface. This study identifies short-term trends and provides an improved description of the lowest portion of the boundary layer over this portion of the Ross Ice Shelf for the February 2011–January 2014 period. Observations indicate two separate initiations of the winter season occur annually, caused by synoptic-scale anomalies. Sensible and latent heat flux estimates are computed using Monin–Obukhov similarity theory and vertical profiles of potential air temperature and wind speed. Over the three years, the monthly mean sensible heat flux ranges between 1 and 39 W m−2 (toward the surface) and the monthly mean latent heat flux ranges between −8 and 0 W m−2. Net heat fluxes directed toward the surface occur most of the year, indicating an atmospheric sink of energy.
50
Tang, Qianhong, Lian Xie, Gary M. Lackmann, and Bin Liu. "Modeling the Impacts of the Large-Scale Atmospheric Environment on Inland Flooding during the Landfall of Hurricane Floyd (1999)." Advances in Meteorology 2013 (2013): 1–16. http://dx.doi.org/10.1155/2013/294956.
Full textAbstract:
The contribution of the large-scale atmospheric environment to precipitation and flooding during Hurricane Floyd was investigated in this study. Through the vortex removal technique in the Weather Research and Forecasting (WRF) model, the vortex associated with Hurricane Floyd (1999) was mostly removed in the model initial conditions and subsequent integration. Results show that the environment-induced precipitation can account for as much as 22% of total precipitation in the innermost model domain covering North Carolina coastal area and 7% in the focused hydrological study area. The high-resolution precipitation data from the WRF model was then used for input in a hydrological model to simulate river runoff. Hydrological simulation results demonstrate that without the tropical systems and their interactions with the large-scale synoptic environment the synoptic environment would only contribute 10% to the total discharge at the Tarboro gauge station. This suggests that Hurricane Floyd and Hurricane Dennis preceding it, along with the interactions between these tropical systems and the large-scale environment, have contributed to the bulk (90%) of the record amount of flood water in the Tar-Pamlico River Basin.