Weather Patterns in Southeast Asia: relationship with tropical variability and heavy precipitation

Author(s):  
Emma Howard ◽  
Simon Thomas ◽  
Thomas H.A. Frame ◽  
Paula L.M. Gonzalez ◽  
John Methven ◽  
...  
2021 ◽  
pp. 1-43
Author(s):  
Wan-Ru Huang ◽  
Ya-Hui Chang ◽  
Liping Deng ◽  
Pin-Yi Liu

AbstractConvective afternoon rainfall (CAR) events, which tend to generate a local rainfall typically in the afternoon, are among the most frequently observed local weather patterns over Southeast Asia during summer. Using satellite precipitation estimations as an observational base for model evaluation, this study examines the applicability of ten global climate models provided by the sixth phase of the Coupled Model Intercomparison Project (CMIP6) in simulating the CAR activities over Southeast Asia. Analyses also focus on exploring the characteristics and maintenance mechanisms of related projections of CAR activities in the future. Our analyses of the historical simulation indicate that EC-Earth3 and EC-Earth3-Veg are the two best models for simulating CAR activities (including amount, frequency, and intensity) over Southeast Asia. Analyses also demonstrate that EC-Earth3 and EC-Earth3-Veg outperform their earlier version (i.e., EC-Earth) in CMIP5 owing to the increase in its spatial resolution in CMIP6. For future projections, our examinations of the differences in CAR activities between the future (2071–2100, under the ssp858 run) and the present (1985–2014, under historical run) indicate that CAR events will become fewer but more intense over most land areas of Southeast Asia. Possible causes of the projected increase (decrease) in CAR intensity (frequency) are attributed to the projected increase (decrease) in the local atmospheric humidity (sea breeze convergence and daytime thermal instability). These findings provide insight into how the local weather/climate over Southeast Asia is likely to change under global warming.


SOLA ◽  
2020 ◽  
Vol 16 (0) ◽  
pp. 125-131
Author(s):  
Takafumi Miyasaka ◽  
Hiroaki Kawase ◽  
Tosiyuki Nakaegawa ◽  
Yukiko Imada ◽  
Izuru Takayabu

2005 ◽  
Vol 3 (4) ◽  
pp. 469-474 ◽  
Author(s):  
Iain R. Lake ◽  
Graham Bentham ◽  
R. Sari Kovats ◽  
Gordon L. Nichols

Outbreaks of cryptosporidiosis have been linked to weather patterns such as heavy precipitation. However, outbreaks only account for a small percentage of all cryptosporidiosis cases and so the causes of the majority of cases are uncertain. This study assessed the role of environmental factors in all cases of cryptosporidiosis by using ordinary least-squares regression to examine the relationship between the monthly cryptosporidiosis rate, and the weather and river flows in England and Wales between 1989 and 1996. Between April and July the cryptosporidiosis rate was positively related to maximum river flow in the current month. Between August and November cryptosporidiosis was also positively linked to maximum river flows in the current month but only after accounting for the previous month's temperature, precipitation and monthly cryptosporidiosis rate. No associations were found between December and March. Through an understanding of the environmental processes at work, these relationships are all consistent with an animal to human transmission pathway especially as the relationships vary throughout the year. This study therefore indicates the importance of an animal to human transmission pathway for all cases of cryptosporidiosis.


2015 ◽  
Vol 16 (2) ◽  
pp. 688-701 ◽  
Author(s):  
Masamichi Ohba ◽  
Shinji Kadokura ◽  
Yoshikatsu Yoshida ◽  
Daisuke Nohara ◽  
Yasushi Toyoda

Abstract Anomalous weather patterns (WPs) in relation to heavy precipitation events during the baiu season in Japan are investigated using a nonlinear classification technique known as the self-organizing map (SOM). The analysis is performed on daily time scales using the Japanese 55-year Reanalysis Project (JRA-55) to determine the role of circulation and atmospheric moisture on extreme events and to investigate interannual and interdecadal variations for possible linkages with global-scale climate variability. SOM is simultaneously employed on four atmospheric variables over East Asia that are related to baiu front variability, whereby anomalous WPs that dominated during the 1958–2011 period are obtained. Our analysis extracts seven typical WPs, which are linked to frequent occurrences of heavy precipitation events. Each WP is associated with regional variations in the probability of extreme precipitation events. On interannual time scales, El Niño–Southern Oscillation (ENSO) affects the frequency of the WPs in relation to the heavy rainfall events. The warm phase of ENSO results in an increased frequency of a WP that provides a southwesterly intrusion of high equivalent potential temperature at low levels, while the cold phase provides southeastern intrusion. In addition, the results of this analysis suggest that interdecadal variability of frequency for heavy rainfall events corresponds to changes in frequency distributions of WPs and are not due to one particular WP.


1961 ◽  
Vol 2 (2) ◽  
pp. 73-105 ◽  
Author(s):  
John R. W. Small

It is generally accepted that history is an element of culture and the historian a member of society, thus, in Croce's aphorism, that the only true history is contemporary history. It follows from this that when there occur great changes in the contemporary scene, there must also be great changes in historiography, that the vision not merely of the present but also of the past must change.


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