Linking Large‐scale Circulation Descriptors to Precipitation Variability in the Northern French Alps

2021 ◽  
Author(s):  
Antoine Blanc ◽  
Juliette Blanchet ◽  
Jean‐Dominique Creutin
Keyword(s):  
Large Scale ◽  
Precipitation Variability ◽  
Large Scale Circulation ◽  
French Alps

scholarly journals Linking Large-scale Circulation Descriptors to Precipitation Variability in the Northern French Alps

2021 ◽  
Author(s):  
Antoine Blanc ◽  
Juliette Blanchet ◽  
Jean-Dominique Creutin
Keyword(s):  
Pressure Difference ◽  
Large Scale ◽  
Western Europe ◽  
Precipitation Variability ◽  
Medium Size ◽  
Maximum Pressure ◽  
Large Scale Circulation ◽  
French Alps ◽  
Mountainous Catchment ◽  
The North

<p>This work analyses the link between Western Europe large-scale circulation and precipitation variability in the Northern French Alps from 1950 to 2017. We consider simple descriptors characterizing the daily 500hPa geopotential height fields. They are the Maximum Pressure Difference - representing the range of geopotential heights over Western Europe -, and the singularity - representing the mean distance between a geopotential shape and its closest analogs, i.e. the way this geopotential shape is reproduced in the climatology. These descriptors are compared to the occurrence of different atmospheric influences - Atlantic, Mediterranean, Northeast, Anticyclonic - and to the leading mode of large-scale circulation variability over Europe - the North Atlantic Oscillation (NAO) - for explaining precipitation variability in the Isère River catchment from one day to 10 years. We show that the Maximum Pressure Difference and the singularity of geopotential shapes explain a significant part of precipitation variability in the Northern French Alps from 10 days to 10 years, especially in winter (correlation values of 0.7). These descriptors provide much better performance than NAO and the same performance as the occurrence of the Atlantic influence, which is the best performing atmospheric influence. This means that simple characteristics of large-scale circulation - that are easy to implement - provide as much information as weather pattern classification to explain precipitation variability over a medium size mountainous catchment. Furthermore, we show that NAO does not drive the pressure gradient in a domain spreading from the Iberic Peninsula to Southern Great Britain and weakly explains precipitation variability in the Northern French Alps.</p>

Linking Large-scale Circulation Descriptors to Precipitation Variability in the Northern French Alps

2021 ◽  
Author(s):  
Antoine Blanc ◽  
Juliette Blanchet ◽  
Jean-Dominique Creutin
Keyword(s):  
Pressure Difference ◽  
Large Scale ◽  
Western Europe ◽  
Precipitation Variability ◽  
Maximum Pressure ◽  
Large Scale Circulation ◽  
French Alps ◽  
The North ◽  
Height Fields ◽  
The North Atlantic Oscillation

<p>This work analyses the link between Western Europe large-scale circulation and precipitation variability in the Northern French Alps from 1950 to 2017. We consider simple descriptors characterizing the daily 500hPa geopotential height fields. They are the Maximum Pressure Difference - representing the range of geopotential heights over Western Europe -, and the singularity - representing the mean distance between a geopotential shape and its closest analogs, i.e. the way this geopotential shape is reproduced in the climatology. These descriptors are compared to the occurrence of different atmospheric influences - Atlantic, Mediterranean, Northeast, Anticyclonic - and to the leading mode of large-scale circulation variability over Europe - the North Atlantic Oscillation (NAO) - for explaining precipitation variability in the Isère River catchment from one day to 10 years. We show that the Maximum Pressure Difference and the singularity of geopotential shapes explain a significant part of precipitation variability in the Northern French Alps from 10 days to 10 years, especially in winter (correlation values of 0.7). These descriptors provide much better performance than NAO and the same performance as the occurrence of the Atlantic influence, which is the best performing atmospheric influence. This means that simple characteristics of large-scale circulation - that are easy to implement - provide as much information as weather pattern classification to explain precipitation variability in the Northern French Alps.</p>

scholarly journals Characteristics of Large-Scale Circulation Affecting the Inter-Annual Precipitation Variability in Northern Sumatra Island during Boreal Summer

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 136
Author(s):  
Yahya Darmawan ◽  
Huang-Hsiung Hsu ◽  
Jia-Yuh Yu
Keyword(s):  
Large Scale ◽  
Precipitation Variability ◽  
Specific Humidity ◽  
Boreal Summer ◽  
Moisture Budget ◽  
Large Scale Circulation ◽  
Budget Analysis ◽  
Sumatra Island ◽  
Precipitation Anomalies ◽  
The Impact

This study aims to explore the contrasting characteristics of large-scale circulation that led to the precipitation anomalies over the northern parts of Sumatra Island. Further, the impact of varying the Asian–Australian Monsoon (AAM) was investigated for triggering the precipitation variability over the study area. The moisture budget analysis was applied to quantify the most dominant component that induces precipitation variability during the JJA (June, July, and August) period. Then, the composite analysis and statistical approach were applied to confirm the result of the moisture budget. Using the European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Anaysis Interim (ERA-Interim) from 1981 to 2016, we identified 9 (nine) dry and 6 (six) wet years based on precipitation anomalies, respectively. The dry years (wet years) anomalies over the study area were mostly supported by downward (upward) vertical velocity anomaly instead of other variables such as specific humidity, horizontal velocity, and evaporation. In the dry years (wet years), there is a strengthening (weakening) of the descent motion, which triggers a reduction (increase) of convection over the study area. The overall downward (upward) motion of westerly (easterly) winds appears to suppress (support) the convection and lead to negative (positive) precipitation anomaly in the whole region but with the largest anomaly over northern parts of Sumatra. The AAM variability proven has a significant role in the precipitation variability over the study area. A teleconnection between the AAM and other global circulations implies the precipitation variability over the northern part of Sumatra Island as a regional phenomenon. The large-scale tropical circulation is possibly related to the PWC modulation (Pacific Walker Circulation).

Precipitation variability (1956–2002) in the Dongjiang River (Zhujiang River basin, China) and associated large-scale circulation

2011 ◽  
Vol 244 (2) ◽  
pp. 130-137 ◽  
Author(s):  
Yongqin David Chen ◽  
Qiang Zhang ◽  
Xixi Lu ◽  
Shurong Zhang ◽  
Zengxin Zhang
Keyword(s):  
River Basin ◽  
Large Scale ◽  
Precipitation Variability ◽  
Large Scale Circulation ◽  
Dongjiang River ◽  
Zhujiang River

scholarly journals Observed winter Alpine precipitation variability and links with large-scale circulation patterns

2001 ◽  
Vol 17 ◽  
pp. 275-284 ◽  
Author(s):  
R Quadrelli ◽  
M Lazzeri ◽  
C Cacciamani ◽  
S Tibaldi
Keyword(s):  
Large Scale ◽  
Precipitation Variability ◽  
Large Scale Circulation ◽  
Circulation Patterns
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