Favorable Circulation Patterns and Moisture Sources for Wintertime Extreme Precipitation Events Over the Balkhash‐Junggar Region

2020 ◽  
Vol 125 (16) ◽  
Author(s):  
Xinsheng He ◽  
Wenyu Huang ◽  
Zifan Yang ◽  
Jonathon S. Wright ◽  
Bin Wang ◽  
...  
Keyword(s):  
Extreme Precipitation ◽  
Moisture Sources ◽  
Extreme Precipitation Events ◽  
Circulation Patterns ◽  
Precipitation Events

Trends in Persistent Seasonal-Scale Atmospheric Circulation Patterns Responsible for Seasonal Precipitation Totals and Occurrences of Precipitation Extremes over Canada

2019 ◽  
Vol 32 (21) ◽  
pp. 7105-7126 ◽  
Author(s):  
Xuezhi Tan ◽  
Thian Yew Gan ◽  
Shu Chen ◽  
Daniel E. Horton ◽  
Xiaohong Chen ◽  
...  
Keyword(s):  
Atmospheric Circulation ◽  
Extreme Precipitation ◽  
Circulation Pattern ◽  
Atmospheric Moisture ◽  
Dynamic Changes ◽  
Extreme Precipitation Events ◽  
Circulation Patterns ◽  
Precipitation Changes ◽  
Synoptic Circulation ◽  
Precipitation Events

Abstract Both large-scale atmospheric circulation and moisture content in the atmosphere govern regional precipitation. We partition recent changes in mean, heavy, and extreme precipitation for all seasons over Canada to changes in synoptic circulation patterns (dynamic changes) and in atmospheric moisture conditions (thermodynamic changes) using 500-hPa geopotential height and precipitation data over 1979–2014. Using the self-organizing map (SOM) cluster analysis, we identify statistically significant trends in occurrences of certain synoptic circulation patterns over the Canadian landmass, which have dynamically contributed to observed changes in precipitation totals and occurrence of heavy and extreme precipitation events over Canada. Occurrences of circulation patterns such as westerlies and ridges over western North America and the North Pacific have considerably affected regional precipitation over Canada. Precipitation intensity and occurrences of precipitation extremes associated with each SOM circulation pattern also showed statistically significant trends resulting from thermodynamic changes in the atmospheric moisture supply for precipitation events. A partition analysis based on the thermodynamic–dynamic partition method indicates that most (~90%) changes in mean and extreme precipitation over Canada resulted from changes in precipitation regimes occurring under each synoptic circulation pattern (thermodynamic changes). Other regional precipitation changes resulted from changes in occurrences of synoptic circulation patterns (dynamic changes). Because of the high spatial variability of precipitation response to changes in thermodynamic and dynamic conditions, dynamic contributions could offset thermodynamic contributions to precipitation changes over some regions if thermodynamic and dynamic contributions are in opposition to each other (negative or positive), which would result in minimal changes in precipitation intensity and occurrences of heavy and extreme precipitation events.

scholarly journals Water vapor isotopes indicating rapid shift among multiple moisture sources for the 2018–2019 winter extreme precipitation events in southeastern China

2022 ◽  
Vol 26 (1) ◽  
pp. 117-127
Author(s):  
Tao Xu ◽  
Hongxi Pang ◽  
Zhaojun Zhan ◽  
Wangbin Zhang ◽  
Huiwen Guo ◽  
...  
Keyword(s):  
Water Vapor ◽  
South China ◽  
Extreme Precipitation ◽  
Southeastern China ◽  
China Sea ◽  
Moisture Source ◽  
Moisture Sources ◽  
Source Regions ◽  
Extreme Precipitation Events ◽  
Precipitation Events

Abstract. In the East Asian monsoon region, winter extreme precipitation events occasionally occur and bring great social and economic losses. From December 2018 to February 2019, southeastern China experienced a record-breaking number of extreme precipitation events. In this study, we analyzed the variation in water vapor isotopes and their controlling factors during the extreme precipitation events in Nanjing, southeastern China. The results show that the variations in water vapor isotopes are closely linked to the change in moisture sources. Using a water vapor d-excess-weighted trajectory model, we identified the following five most important moisture source regions: South China, the East China Sea, the South China Sea, the Bay of Bengal, and continental regions (northwestern China and Mongolia). Moreover, the variations in water vapor d excess during a precipitation event reflect rapid shifts in the moisture source regions. These results indicate that rapid shifts among multiple moisture sources are important conditions for sustaining wintertime extreme precipitation events over extended periods.

scholarly journals Investigating changes in atmospheric circulation patterns connected to extreme precipitation in Norway

2021 ◽  
Author(s):  
Karianne Ødemark ◽  
Malte Müller ◽  
Ole Einar Tveito ◽  
Cyril Palerme
Keyword(s):  
Atmospheric Circulation ◽  
Extreme Precipitation ◽  
Good Description ◽  
Construction Technique ◽  
Sea Ice Concentration ◽  
Data Set ◽  
Atmospheric Circulation Patterns ◽  
Extreme Precipitation Events ◽  
Circulation Patterns ◽  
Precipitation Events

<p>Extreme precipitation events that lead to excess surface water and flood are becoming an amplifying societal cost as a result of both the increasing precipitation amounts in recent years and urbanization. Knowledge about extreme precipitation events is important for the ability to predict them, but also to know how often they occur with various intensities in order to estimate design values for constructions and critical infrastructure. A good description of extreme precipitaton is a challenge since observation networks are often too sparse to describe the spatial structure of precipitation, and the highest amounts are most likely not captured by a precipitation gauge. For the study of extreme precipitation events by means of statistical analysis, long timesteries are required, which is a major challenge when using conventional or new observational data records.  Here, a data set constructed from the numerical seasonal prediction system at ECMWF, SEAS5, has been applied to evaluate mechanisms controlling extreme precipitation events. The construction technique gives the ability to increase the event sample size compared to conventional data sets. We analyze 3-day  maximum precipitation events in the September-October-November season for an area on the west coast of Norway, an area subject to the largest precipitation amounts in Europe. A principal component analysis of the 500 hPa geopotential anomaly has been performed to identify atmospheric circulation patterns related to the extreme precipitation events. We find that two of the EOFs are related to precipitation with high return values for the selected area. These two EOFs have a significant trend over the data period, but with opposing signs. We also investigate the connection between both sea surface temperature (SST) and sea-ice concentration in the Barents-Kara sea and the occurrence of extreme precipitation.</p>

scholarly journals Water vapor isotopes indicating rapid shift among multiple moisture sources for the 2018/2019 winter extreme precipitation events in Southeast China

2021 ◽  
Author(s):  
Tao Xu ◽  
Hongxi Pang ◽  
Zhaojun Zhan ◽  
Wangbin Zhang ◽  
Huiwen Guo ◽  
...  
Keyword(s):  
Water Vapor ◽  
South China ◽  
Extreme Precipitation ◽  
Southeast China ◽  
China Sea ◽  
Moisture Source ◽  
Moisture Sources ◽  
Source Regions ◽  
Extreme Precipitation Events ◽  
Precipitation Events

Abstract. In the East Asian monsoon region, winter extreme precipitation events occasionally occur and bring great social and economic losses. From December 2018 to February 2019, Southeast China experienced a record-breaking number of extreme precipitation events. In this study, we analyzed the variation of water vapor isotopes and their controlling factors during the extreme precipitation events in Nanjing, Southeast China. The results show that the variations of water vapor isotopes are closely linked to the change of moisture sources. Using a water vapor d-excess weighted trajectory model, we identified five most important moisture source regions: South China, East China Sea, South China Sea, Bay of Bengal, and Continental regions (Northwest China and Mongolia). Moreover, the variations of water vapor d-excess during a precipitation event reflect rapid shifts of moisture source regions. These results indicate that rapid shifts among multiple moisture sources are important conditions for sustaining wintertime extreme precipitation events over extended periods.

scholarly journals Moisture Sources for Wintertime Extreme Precipitation Events Over South China During 1979–2013

2018 ◽  
Vol 123 (13) ◽  
pp. 6690-6712 ◽  
Author(s):  
Wenyu Huang ◽  
Xinsheng He ◽  
Zifan Yang ◽  
Tianpei Qiu ◽  
Jonathon S. Wright ◽  
...  
Keyword(s):  
South China ◽  
Extreme Precipitation ◽  
Moisture Sources ◽  
Extreme Precipitation Events ◽  
Precipitation Events

scholarly journals Unprecedented loss of surface and cave ice in SE Europe related to record summer rains in 2019

2020 ◽  
Author(s):  
Aurel Persoiu ◽  
Nenad Buzjak ◽  
Alexandru Onaca ◽  
Christos Pennos ◽  
Yorgos Sotiriadis ◽  
...  
Keyword(s):  
Extreme Precipitation ◽  
Climate Models ◽  
Atmospheric Circulation Patterns ◽  
Extreme Precipitation Events ◽  
Alpine Glaciers ◽  
Circulation Patterns ◽  
Synoptic Conditions ◽  
Catastrophic Loss ◽  
Polar Ice Sheets ◽  
Precipitation Events

Abstract. Glaciers worldwide are shrinking at an accelerated rate as the climate changes in response to anthropogenic influence. While increasing air temperature is the main factor behind glacier mass loss, changing atmospheric circulation patterns and the distribution of precipitation also plays a role, though these are not as well understood. Furthermore, while the mass balance of surface glaciers (from large polar ice sheets to small alpine glaciers) is relatively well documented and continuously monitored, little to nothing is known about the response of cave glaciers (perennial ice accumulations in rock-hosted caves) to atmospheric warming. In this context, we present the response of cave and surface glaciers in SE Europe to synoptic conditions in summer 2019. Our investigation shows that extreme precipitation events occurring between May and July 2019 led to catastrophic loss of ice at levels unprecedented during the last century. As climate models predict that such extreme precipitation events are set to increase in frequency and intensity, the presence of cave glaciers in SE Europe and the paleoclimatic information they host may be lost in the near future. Moreover, the same projected continuous warming and increase in precipitation extremes could pose an additional threat to the Alpine glaciers in southern Europe, resulting in faster than predicted melting.

Extreme precipitation events in the Mediterranean area. A contrasting Lagrangian and Eulerian approach for moisture evaporation sources identification.

2020 ◽  
Author(s):  
Sara Cloux González ◽  
A. Daniel Garaboa Paz ◽  
Damian Insua Costa ◽  
Vicente Perez Muñuzuri ◽  
Gonzálo Miguez Macho
Keyword(s):  
Extreme Precipitation ◽  
Lagrangian Model ◽  
Precipitation Event ◽  
Economic Losses ◽  
Correct Identification ◽  
Geophysical Research ◽  
Moisture Sources ◽  
Extreme Precipitation Events ◽  
The Mediterranean ◽  
Precipitation Events

<div> <p>Concern about heavy precipitation events has increasingly grown in the last years in the South of Europe, especially in the Mediterranean region. These occasional episodes can result in more than 200 mm of rainfall in less than 24 h, producing flash floods with very high social and economic losses.  </p> </div><div> <p>To improve their predictability, the correct identification of the origin of the moisture must be done. The Eulerian and Lagrangian models provide a good approach to detect moisture sources. However, they show some limitations. </p> </div><div> <p>Here, we present a comparison between both methods through a case study of an extreme precipitation event on the region of the Mediterranean coast which take place in 1982. Using the Lagrangian model FLEXPART-WRF to backtrack the moisture, we identify the evaporation sources. Then, we compare it with the results obtained through Eulerian WRF-WVT method [1]. Also, we evaluate the accuracy of E-P balance in contrast to Evaporation patterns. Finally, we implemented a further identification of moisture uptake method which enables us to directly compare results from both strategies [2]. </p> </div><div> <p> </p> </div><div> <p>[1] Insua-Costa, D., Miguez-Macho, G., and Llasat, M. C.: Local and remote moisture sources for extreme precipitation: a study of the two catastrophic 1982 western Mediterranean episodes, Hydrol. Earth Syst. Sci., 23, 3885–3900, https://doi.org/10.5194/hess-23-3885-2019, 2019. </p> </div><div> <p>[2] Sodemann, Harald, C. Schwierz, and Heini Wernli.: Interannual variability of Greenland winter precipitation sources: Lagrangian moisture diagnostic and North Atlantic Oscillation influence. Journal of Geophysical Research: Atmospheres 113.D3 (2008). </p> </div>

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