Spatiotemporal variation in temperature extremes and their association with large scale circulation patterns in the Central Karakorum during 1982–2019

Abstract Forecasting extreme events is important for having more time to prepare and mitigate high-impact events because those are expected to become more frequent, intense, and persistent around the globe in the future under the warming atmosphere. This study evaluates the probabilistic predictability of the heat wave index (HWI) associated with large-scale circulation patterns for predicting heat waves over South Korea. The HWI, reflecting heat waves over South Korea, was defined as the vorticity difference at 200 hPa between the South China Sea and northeast Asia. The forecast of up to 15 days from five ensemble prediction systems and the multimodel ensemble has been used to predict the probabilistic HWI during the summers of 2011–15. The ensemble prediction systems consist of different five operational centers, and the forecast skill of the probability of heat waves occurrence was assessed using the Brier skill score (BSS), relative operating characteristics (ROC), and reliability diagram. It was found that the multimodel ensemble is capable of better predicting the large-scale circulation patterns leading to heat waves over South Korea than any other single ensemble system through all forecast lead times. We concluded that the probabilistic forecast of the HWI has promise as a tool to take appropriate and timely actions to minimize the loss of lives and properties from imminent heat waves.

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Large-scale circulation patterns and related rainfall in the Amazon Basin: a neuronal networks approach

Climate Dynamics ◽

10.1007/s00382-011-1010-8 ◽

2011 ◽

Vol 38 (1-2) ◽

pp. 121-140 ◽

Cited By ~ 34

Author(s):

Jhan Carlo Espinoza ◽

Matthieu Lengaigne ◽

Josyane Ronchail ◽

Serge Janicot

Keyword(s):

Large Scale ◽

Amazon Basin ◽

Neuronal Networks ◽

Large Scale Circulation ◽

Circulation Patterns

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Predictability of large scale drivers leading intense Mediterranean cyclones

10.5194/egusphere-egu2020-13717 ◽

2020 ◽

Author(s):

M. Carmen Alvarez-Castro ◽

Silvio Gualdi ◽

Pascal Yiou ◽

Mathieu Vrac ◽

Robert Vautard ◽

...

Keyword(s):

Climate Change ◽

Large Scale ◽

Human Life ◽

Heavy Precipitation ◽

Mediterranean Area ◽

Frequency Of Occurrence ◽

Large Scale Circulation ◽

Mediterranean Cyclones ◽

Circulation Patterns ◽

Anthropogenic Forcings

<p>Windstorms, extreme precipitations and instant floods seems to strike the Mediterranean area with increasing frequency. These events occur simultaneously during intense tropical-like Mediterranean cyclones. These intense Mediterranean cyclones are frequently associated with wind, heavy precipitation and changes in temperature, generating high risk situations such as flash floods and large-scale floods with significant impacts on human life and built environment. Although the dynamics of these phenomena is well understood, little is know about their climatology. It is therefore very difficult to make statements about the frequency of occurrence and its response to climate change. Thus, intense Mediterranean cyclones have many different physical aspects that can not be captured by a simple standard approach.&#160;</p><p>The first challenge of this work is to provide an extended catalogue and climatology of these phenomena by reconstructing a database of intense Mediterranean cyclones dating back up to 1969 using the satellite, the literature and reanalyses. Applying a method based on dynamical systems theory we analyse and attribute their future changes under different anthropogenic forcings by using future simulations within CMIP framework. Preliminary results show a decrease of the large-scale circulation patterns favoring intense Mediterranean cyclones in all the seasons except summer.</p>

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Large scale circulation patterns of the stratosphere

Space Science Reviews ◽

10.1007/bf00175315 ◽

1972 ◽

Vol 13 (2) ◽

Cited By ~ 6

Author(s):

Barbara Kriester

Keyword(s):

Large Scale ◽

Large Scale Circulation ◽

Circulation Patterns

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Greenland accumulation and its connection to the large-scale atmospheric circulation in ERA-Interim and paleo-climate simulations

Climate of the Past Discussions ◽

10.5194/cpd-9-3825-2013 ◽

2013 ◽

Vol 9 (4) ◽

pp. 3825-3870

Author(s):

N. Merz ◽

C. C. Raible ◽

H. Fischer ◽

V. Varma ◽

M. Prange ◽

...

Keyword(s):

Atmospheric Circulation ◽

Large Scale ◽

Ice Core ◽

Ice Sheet ◽

Greenland Ice Sheet ◽

Circulation Pattern ◽

Local Flow ◽

Large Scale Circulation ◽

Circulation Patterns ◽

Local Accumulation

Abstract. Accumulation and aerosol chemistry records from Greenland ice cores offer the potential to reconstruct variability in Northern Hemisphere atmospheric circulation over the last millennia. However, an important prerequisite for a reconstruction is the stable relationship between local accumulation at the ice core site with the respective circulation pattern throughout the reconstruction period. We address this stability issue by using a comprehensive climate model and performing time-slice simulations for the present, the pre-industrial, the early Holocene and the last glacial maximum (LGM). The relationships between accumulation, precipitation and atmospheric circulation are investigated on on various time-scales. The analysis shows that the relationship between local accumulation on the Greenland ice sheet and the large-scale circulation undergoes a significant seasonal cycle. As the weights of the individual seasons change, annual mean accumulation variability is not necessarily related to the same atmospheric circulation patterns during the different climate states. Within a season, local Greenland accumulation variability is indeed linked to a consistent circulation pattern, which is observed for all studied climate periods, even for the LGM, however these circulation patterns are specific for different regions on the Greenland ice sheet. The simulated impact of orbital forcing and changes in the ice-sheet topography on accumulation exhibits strong spatial variability emphasizing that accumulation records from different ice core sites cannot be expected to look alike since they include a distinct local signature. Accumulation changes between different climate periods are dominated by changes in the amount of snowfall and are driven by both thermodynamic and dynamic factors. The thermodynamic impact determines the strength of the hydrological cycle, and warmer temperatures are generally accompanied by an increase in Greenland precipitation. Dynamical drivers of accumulation changes are the large-scale circulation and the local orography having a distinct influence on the local flow characteristic and hence the amount of precipitation deposited in any Greenland region.

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