Variability of large-scale atmospheric circulation indices for the northern hemisphere during the past 100 years

2009 ◽  
Vol 18 (4) ◽  
pp. 379-396 ◽  
Author(s):  
Stefan Brönnimann ◽  
Alexander Stickler ◽  
Thomas Griesser ◽  
Andreas M. Fischer ◽  
Andrea Grant ◽  
...  
Keyword(s):  
Atmospheric Circulation ◽  
Northern Hemisphere ◽  
Large Scale ◽  
The Past ◽  
Atmospheric Circulation Indices ◽  
Circulation Indices ◽  
Large Scale Atmospheric Circulation

scholarly journals Multiscale variability of streamflow in the Three Rivers Headwater Region, China, and links to large-scale atmospheric circulation indices

2020 ◽  
Author(s):  
Jian Tang ◽  
Huiqun Cao
Keyword(s):  
Atmospheric Circulation ◽  
Large Scale ◽  
Source Region ◽  
Early Years ◽  
The Tibetan Plateau ◽  
Atmospheric Circulation Indices ◽  
Increasing Trend ◽  
Circulation Indices ◽  
Three Rivers ◽  
Large Scale Atmospheric Circulation

Abstract Exploring the relations between streamflow and large-scale atmospheric circulation systems can assist in identifying potentially useful indicators for the modeling of hydrological processes. With the help of ensemble empirical mode decomposition and the wavelet analysis method, this research explored streamflow variations and its links to large-scale atmospheric circulation indices during 1960–2012 in the Three Rivers Headwater Region (TRHR). A steady increasing trend was detected in the streamflow of the source region of Yangtze River (SYR), and a steady decreasing trend was detected in the streamflow of the source region of Lancang River (SLR). The streamflow of the source region of Yellow River (SYeR) had an increasing trend in the early years of the study period and subsequently exhibited a decreasing trend. The Tibetan Plateau monsoon (TPM), Arctic Oscillation (AO), and South Asia monsoon (SAM) are the key factors influencing streamflow changes in the SYR, SYeR, and SLR, respectively. At interannual time-scale variation with the period of about 3–9 years, an antiphase relationship exists between SYR streamflow and TPM indices, while in-phase relationships are detected between SYeR (SLR) streamflow and AO (SAM) indices.

INFLUENCE OF LARGE-SCALE ATMOSPHERIC PROCESSES ON SEASONAL RUNOFF OF LARGE SIBERIAN RIVERS

2021 ◽  
pp. 36-47
Author(s):  
L. N. VASILEVSKAYA ◽  
◽  
I. A. LISINA ◽  
D. N. VASILEVSKII ◽  
◽  
...  
Keyword(s):  
Atmospheric Circulation ◽  
River Runoff ◽  
Large Scale ◽  
Annual Runoff ◽  
Spring Flood ◽  
Atmospheric Circulation Indices ◽  
Rate Of Increase ◽  
Circulation Indices ◽  
Seasonal Runoff ◽  
Kolyma River

Based on daily runoff volumes of four large Siberian rivers (the Ob, Yenisei, Lena, and Kolyma) for 1936-2018, the regime and changes in the total annual and seasonal runoff are analyzed. High synchronous and asynchronous correlations between monthly river runoff and atmospheric circulation indices of hemispheric and regional scales are revealed. In recent decades, the total annual runoff and its variations have increased (the rate of increase is most pronounced for the Kolyma River). A change in water content within a year is heterogeneous: weak positive trends are characteristic of the spring flood runoff and the summer-autumn period, and a significant increase occurred in the winter months. High correlations with a 1-8-month shift made it possible to identify the most informative regions, the atmospheric circulation over which makes a certain contribution to the variance of river runoff.

scholarly journals Winter hydrometeorological extreme events modulated by large scale atmospheric circulation in southern Ontario

2019 ◽  
Author(s):  
Olivier Champagne ◽  
Martin Leduc ◽  
Paulin Coulibaly ◽  
M. Altaf Arain
Keyword(s):  
Atmospheric Circulation ◽  
Extreme Events ◽  
Large Scale ◽  
Internal Variability ◽  
Southern Ontario ◽  
Future Evolution ◽  
The Past ◽  
The Future ◽  
High Flows ◽  
Large Scale Atmospheric Circulation

Abstract. Extreme events are widely studied across the world because of their major implications for many aspects of society and especially floods. These events are generally studied in term of precipitation or temperature extreme indices that are often not adapted for regions affected by floods caused by snowmelt. Rain on Snow index has been widely used but it neglects rain only events which are expected to be more frequent in the future. In this study we identified a new winter compound index and assessed how large-scale atmospheric circulation controls the past and future evolution of these events in the Great Lakes region. The future evolution of this index was projected using temperature and precipitation from the Canadian Regional Climate Model Large Ensemble (CRCM5-LE). These climate data were used as input in PRMS hydrological model to simulate the future evolution of high flows in three watersheds in Southern Ontario. We also used five recurrent large-scale atmospheric circulation patterns in northeastern North America and identified how they control the past and future variability of the newly created index and high flows. The results show that daily precipitation higher than 10 mm and temperature higher than 5 °C were a necessary historical condition to produce high flows in these three watersheds. In the historical period, the occurrences of these heavy rain and warm events as well as high flows were associated to two main patterns characterized by high Z500 anomalies centred on eastern Great Lakes (HP) and the Atlantic Ocean (South). These hydrometeorological extreme events will be more frequent in the near future and will still be associated to the same atmospheric patterns. The future evolution of the index will be modulated by the internal variability of the climate system as higher Z500 in the east coast will amplify the increase in the number of events, especially the warm events. The relationship between the extreme weather index and high flows will be modified in the future as the snowpack reduces and rain becomes the main component of high flows generation. This study shows the values of CRCM5-LE dataset to simulate hydrometeorological extreme events in Eastern Canada and to better understand the uncertainties associated to internal variability of climate.

scholarly journals Winter hydrometeorological extreme events modulated by large-scale atmospheric circulation in southern Ontario

2020 ◽  
Vol 11 (1) ◽  
pp. 301-318 ◽  
Author(s):  
Olivier Champagne ◽  
Martin Leduc ◽  
Paulin Coulibaly ◽  
M. Altaf Arain
Keyword(s):  
Atmospheric Circulation ◽  
Extreme Events ◽  
Large Scale ◽  
Internal Variability ◽  
Southern Ontario ◽  
Future Evolution ◽  
The Past ◽  
The Future ◽  
High Flows ◽  
Large Scale Atmospheric Circulation

Abstract. Extreme events are widely studied across the world because of their major implications for many aspects of society and especially floods. These events are generally studied in terms of precipitation or temperature extreme indices that are often not adapted for regions affected by floods caused by snowmelt. The rain on snow index has been widely used, but it neglects rain-only events which are expected to be more frequent in the future. In this study, we identified a new winter compound index and assessed how large-scale atmospheric circulation controls the past and future evolution of these events in the Great Lakes region. The future evolution of this index was projected using temperature and precipitation from the Canadian Regional Climate Model large ensemble (CRCM5-LE). These climate data were used as input in Precipitation Runoff Modelling System (PRMS) hydrological model to simulate the future evolution of high flows in three watersheds in southern Ontario. We also used five recurrent large-scale atmospheric circulation patterns in north-eastern North America and identified how they control the past and future variability of the newly created index and high flows. The results show that daily precipitation higher than 10 mm and temperature higher than 5 ∘C were necessary historical conditions to produce high flows in these three watersheds. In the historical period, the occurrences of these heavy rain and warm events as well as high flows were associated with two main patterns characterized by high Z500 anomalies centred on eastern Great Lakes (HP regime) and the Atlantic Ocean (South regime). These hydrometeorological extreme events will still be associated with the same atmospheric patterns in the near future. The future evolution of the index will be modulated by the internal variability of the climate system, as higher Z500 on the east coast will amplify the increase in the number of events, especially the warm events. The relationship between the extreme weather index and high flows will be modified in the future as the snowpack reduces and rain becomes the main component of high-flow generation. This study shows the value of the CRCM5-LE dataset in simulating hydrometeorological extreme events in eastern Canada and better understanding the uncertainties associated with internal variability of climate.

The main features of large-scale atmospheric circulation in the context of analyzing the consensus forecast of air temperature and precipitation for the 2020 Northern Eurasia summer

2021 ◽  
pp. 20-35
Author(s):  
R.M. Vilfand ◽  
◽  
K.A. Sumerova , ◽  
V.A. Tishchenko ◽  
V.M. Khan ◽  
...  
Keyword(s):  
Atmospheric Circulation ◽  
Air Temperature ◽  
Large Scale ◽  
Precipitation Forecast ◽  
Northern Eurasia ◽  
Temperature And Precipitation ◽  
Skill Scores ◽  
Circulation Indices ◽  
Arctic Ice ◽  
Large Scale Atmospheric Circulation

The main results of the analysis of the Northern Hemisphere large-scale atmospheric circulation features are presented for the 2020 summer. Skill scores of the consensus forecast for the 2020 Northern Eurasia summer are discussed in the context of analyzing the large-scale atmospheric circulation. The prognostic potential of the trend component in forecasting seasonal anomalies of air temperature and precipitation is noted. Keywords: air temperature, precipitation, forecast skill, trends, large-scale atmospheric circulation, sea surface temperature, NEACOF, circulation indices, Arctic ice

Precipitation variability in the Meuse basin in relation to atmospheric circulation

2005 ◽  
Vol 51 (5) ◽  
pp. 5-14 ◽  
Author(s):  
M. Tu ◽  
P.J.M. de Laat ◽  
M.J. Hall ◽  
M.J.M. de Wit
Keyword(s):  
Statistical Analysis ◽  
Atmospheric Circulation ◽  
Large Scale ◽  
Precipitation Variability ◽  
Past Century ◽  
The Past ◽  
Winter Half ◽  
Summer Half ◽  
Large Scale Atmospheric Circulation ◽  
Precipitation Events

The distribution of precipitation events in the Meuse basin during the past century has been found to reflect the large-scale atmospheric circulation, as characterised by the Grosswetterlagen system. Statistical analysis of the long observation records (1911–2002) for the basin showed that although the annual (November to October) and winter half-year (November to April) frequencies of wet days (≥1 mm/day) were nearly stable, the associated precipitation amounts have significantly increased since 1980. From 1980 onwards, the very wet days (≥10 mm/day) in the winter half-year have become more frequent. No obvious change was identified for the summer half-year (May to October) very wet days. Both the precipitation amounts of wet and very wet days in the winter half-year and the occurrence of associated atmospheric circulation of the types/sub-types west cyclone, southwest cyclone and northwest cyclone showed a significant increase around 1980.

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