Atmospheric circulation regime causing winter temperature whiplash events in North China

2020 ◽  
Author(s):  
Shuangmei Ma ◽  
Congwen Zhu
Keyword(s):  
Atmospheric Circulation ◽  
North China ◽  
Winter Temperature ◽  
Circulation Regime

scholarly journals Spring Extreme Precipitation Days in North China and Their Reliance on Atmospheric Circulation Patterns During 1979–2019

2022 ◽  
pp. 1-41
Keyword(s):  
Climate Variability ◽  
Atmospheric Circulation ◽  
Extreme Precipitation ◽  
Interannual Variation ◽  
North China ◽  
Circulation Pattern ◽  
Southerly Wind ◽  
Atmospheric Circulation Patterns ◽  
Rain Gauges ◽  
Circulation Patterns

Abstract The interannual variation of springtime extreme precipitation (SEP) days in North China (NC) and their reliance on atmospheric circulation patterns are studied by using the continuous daily record of 396 rain gauges and the fifth generation of the European Centre for Medium-Range Weather Forecasts atmospheric reanalysis during 1979–2019. The SEP days are defined as the days when at least 10% of rain gauges in NC record daily precipitation no less than 10.5 mm. Results show that the number of SEP days shows large interannual variability but no significant trend in the study period. Using the objective classification method of the obliquely rotated principal analysis in T-mode, we classify the atmospheric circulation into five different patterns based on the geopotential height at 700 hPa. Three circulation patterns all have fronts and are associated with strong southerly wind, leading to 88% of SEP days in NC. The strong southerly wind may provide moisture and dynamic forcing for the frontal precipitation. The interannual variation of SEP days is related with the number of the three above-mentioned dominant circulation patterns. Further analysis shows that the West Pacific pattern could be one of the possible climate variability modes related to SEP days. This study reveals that the daily circulation pattern may be the linkage between SEP days and climate variability modes in NC.

Changes in prevailing surface-paleowinds reveal the atmospheric circulation transition during Early Cretaceous in North China

2022 ◽  
Vol 586 ◽  
pp. 110784
Author(s):  
Dawei Qiao ◽  
Nan Peng ◽  
Hongwei Kuang ◽  
Yongqing Liu ◽  
Yanxue Liu ◽  
...  
Keyword(s):  
Atmospheric Circulation ◽  
Early Cretaceous ◽  
North China

scholarly journals Relating snowfall observations to Greenland ice sheet mass changes: an atmospheric circulation perspective

2021 ◽  
Author(s):  
Michael Gallagher ◽  
Matthew Shupe ◽  
Hélène Chepfer ◽  
Tristan L'Ecuyer
Keyword(s):  
Spatial Variability ◽  
Mass Loss ◽  
Mass Balance ◽  
Atmospheric Circulation ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Circulation Pattern ◽  
Mass Gain ◽  
Spatial And Temporal Variability ◽  
Circulation Regime

Abstract. Snowfall is the major source of mass for the Greenland ice sheet but the spatial and temporal variability of its contributions to mass balance have so far been inadequately quantified. By characterizing local atmospheric circulation and utilizing CloudSat spaceborne radar observations of snowfall, we provide a detailed spatial analysis of snowfall variability and its relationship to Greenland mass balance, presenting first-of-their-kind daily maps of the spatial variability in snowfall from observations across Greenland. For identified regional atmospheric circulation patterns, we show that the spatial distribution and net mass input of snowfall varies significantly with the position and strength of surface cyclones. Cyclones west of Greenland driving southerly flow contribute significantly more snowfall than any other circulation regime, with each daily occurrence of the most extreme southerly circulation pattern is contributes an average of 1.66 Gt of snow to the Greenland ice sheet. While cyclones east of Greenland, patterns with the least snowfall, contribute as little as 0.58 Gt each day. Above 2 km on the ice sheet where snowfall is inconsistent, extreme southerly patterns are the most significant mass contributors, with up to 1.20 Gt of snowfall above this elevation. This analysis demonstrates that snowfall over the interior of Greenland varies by up to a factor of five depending on regional circulation conditions. Using independent observations of mass changes made by the Gravity Recovery and Climate Experiment (GRACE), we verify that the largest mass increases are tied to the southerly regime with cyclones west of Greenland. For occurrences of the strongest southerly pattern, GRACE indicates a net mass increase of 1.29 Gt in the ice sheet accumulation zone (above 2 km elevation) compared to the 1.20 Gt of snowfall observed by CloudSat. This good overall agreement suggests that the analytical approach presented here can be used to directly quantify snowfall mass contributions and their most significant drivers spatially across the GrIS. While previous research has implicated this same southerly regime in ablation processes during summer, this paper shows that ablation mass loss in this circulation regime is nearly an order of magnitude larger than the mass gain from associated snowfall. For daily occurrences of the southerly circulation regime, a mass loss of approximately 11 Gt is observed across the ice sheet despite snowfall mass input exceeding one gigatonne. By analyzing the spatial variability of snowfall and mass changes, this research provides new insight into connections between regional atmospheric circulation and GrIS mass balance.

scholarly journals On the Linkage between the Extreme Drought and Pluvial Patterns in China and the Large-Scale Atmospheric Circulation

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Zengxin Zhang ◽  
Qiu Jin ◽  
Xi Chen ◽  
Chong-Yu Xu ◽  
Shanshan Jiang
Keyword(s):  
Atmospheric Circulation ◽  
South China ◽  
Large Scale ◽  
North China ◽  
Western Pacific Subtropical High ◽  
Extreme Drought ◽  
Height Anomaly ◽  
Monthly Precipitation ◽  
Atmospheric Moisture ◽  
Large Scale Atmospheric Circulation

China is a nation that is affected by a multitude of natural disasters, including droughts and floods. In this paper, the variations of extreme drought and pluvial patterns and their relations to the large-scale atmospheric circulation have been analyzed based on monthly precipitation data from 483 stations during the period 1958–2010 in China. The results show the following:(1)the extreme drought and pluvial events in China increase significantly during that period. During 1959–1966 timeframe, more droughts occur in South China and more pluvial events are found in North China (DSC-PNC pattern); as for the period 1997–2003 (PSC-DNC pattern), the situation is the opposite.(2)There are good relationships among the extreme drought and pluvial events and the Western Pacific Subtropical High, meridional atmospheric moisture flux, atmospheric moisture content, and summer precipitation.(3)A cyclone atmospheric circulation anomaly occurs in North China, followed by an obvious negative height anomaly and a southern wind anomaly at 850 hPa and 500 hPa for the DSC-PNC pattern during the summer, and a massive ascending airflow from South China extends to North China at ~50∘N. As for the PSC-DNC pattern, the situation contrasts sharply with the DSC-PNC pattern.

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