The Large-Scale Circulation Change at the End of the Baiu Season in Japan as Seen in ERA40 Data

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).

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Large‐scale circulation features responsible for different types of extreme high temperatures with extreme coverage over South China

International Journal of Climatology ◽

10.1002/joc.7283 ◽

2021 ◽

Author(s):

Wenting Lin ◽

Ruidan Chen ◽

Zhiping Wen ◽

Wei Chen

Keyword(s):

High Temperatures ◽

South China ◽

Large Scale ◽

Large Scale Circulation ◽

Different Types

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2016 Monsoon Convection and its place in the Large-Scale Circulation using Doppler Radars

10.1002/essoar.10504086.2 ◽

2021 ◽

Author(s):

Alexander John Doyle ◽

Thorwald Hendrik Matthias Stein ◽

Andrew Turner

Keyword(s):

Large Scale ◽

Large Scale Circulation

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Observed trends in extreme precipitation events in China during 1961–2001 and the associated changes in large-scale circulation

Geophysical Research Letters ◽

10.1029/2005gl022574 ◽

2005 ◽

Vol 32 (9) ◽

Cited By ~ 177

Author(s):

Yuqing Wang

Keyword(s):

Extreme Precipitation ◽

Large Scale ◽

Large Scale Circulation ◽

Extreme Precipitation Events ◽

Precipitation Events

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An inverse model of the large scale circulation in the South Indian Ocean

Progress In Oceanography ◽

10.1016/j.pocean.2007.02.001 ◽

2007 ◽

Vol 74 (1) ◽

pp. 71-94 ◽

Cited By ~ 13

Author(s):

E. Sultan ◽

H. Mercier ◽

R.T. Pollard

Keyword(s):

Indian Ocean ◽

Large Scale ◽

Inverse Model ◽

The South ◽

South Indian Ocean ◽

Large Scale Circulation ◽

South Indian

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Unravelling the large-scale circulation modes in turbulent Rayleigh–Bénard convection

EPL (Europhysics Letters) ◽

10.1209/0295-5075/ac3da2 ◽

2021 ◽

Author(s):

Susanne Horn ◽

Peter J. Schmid ◽

Jonathan M. Aurnou

Keyword(s):

Large Scale ◽

Three Dimensional ◽

Dynamic Mode Decomposition ◽

Dynamic Mode ◽

Mean Flow ◽

Large Scale Circulation ◽

Convective Systems ◽

Aspect Ratios ◽

Mode Decomposition ◽

Coherent Flow Structure

Abstract The large-scale circulation (LSC) is the most fundamental turbulent coherent flow structure in Rayleigh-B\'enard convection. Further, LSCs provide the foundation upon which superstructures, the largest observable features in convective systems, are formed. In confined cylindrical geometries with diameter-to-height aspect ratios of Γ ≅ 1, LSC dynamics are known to be governed by a quasi-two-dimensional, coupled horizontal sloshing and torsional (ST) oscillatory mode. In contrast, in Γ ≥ √2 cylinders, a three-dimensional jump rope vortex (JRV) motion dominates the LSC dynamics. Here, we use dynamic mode decomposition (DMD) on direct numerical simulation data of liquid metal to show that both types of modes co-exist in Γ = 1 and Γ = 2 cylinders but with opposite dynamical importance. Furthermore, with this analysis, we demonstrate that ST oscillations originate from a tilted elliptical mean flow superposed with a symmetric higher order mode, which is connected to the four rolls in the plane perpendicular to the LSC in Γ = 1 tanks.

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