|
" A Synoptic Approach to the South Asian Monsoon Climate "
Islam, Md Rafiqul
Sheridan, Scott
| Document Type
|
:
|
Latin Dissertation
|
| Language of Document
|
:
|
English
|
| Record Number
|
:
|
1054195
|
| Doc. No
|
:
|
TL53312
|
| Main Entry
|
:
|
Islam, Md Rafiqul
|
| Title & Author
|
:
|
A Synoptic Approach to the South Asian Monsoon Climate\ Islam, Md RafiqulSheridan, Scott
|
| College
|
:
|
Kent State University
|
| Date
|
:
|
2020
|
| Degree
|
:
|
Ph.D.
|
| student score
|
:
|
2020
|
| Note
|
:
|
173 p.
|
| Abstract
|
:
|
Understanding the South Asian seasonal cycle is important. Using a synoptic climatological approach to identify circulation patterns, using the self-organizing maps (SOMs) technique, this research successfully has demonstrated several novel aspects of the seasonal cycle. First, it identifies the south Asian seasonal cycle showing the general climatology in the context of spatio-temporal variation. Second, this research provides an objective estimation of onset and withdrawal dates for four determined seasons (winter, pre-monsoon, monsoon, and post-monsoon). Third, this dissertation provides an understanding of the different possible monsoon mechanisms across the seasons by analyzing multiple atmospheric layers and potential feedback. Categorizing atmospheric patterns individually for each of five surface variables (sea-level pressure, wind, temperature, relative humidity, and precipitation), a 9x9 SOM was created using surface-level data obtained from the NCEP/NCAR Reanalysis 1 project. Nodes are assigned to seasons, as well as seasonal transitions, based on defined standard criteria, and the seasons on the SOMs were determined and partitioned based on their temporal variations. A complete reversal of mean sea-level pressure over the course of the year, with high pressure over the land in winter and low pressure in the summer, and a clear seasonal cycle in wind directions have been observed. The monsoon season can be identified as starting earlier using variables other than precipitation, substantiate prevailing precondition of the atmospheric circulation prior to monsoonal rainfall. The pressure gradient due to land-sea thermal contrast and the movement of ITCZ lead other effective climatological features in different atmospheric layers, are the most important driving force for monsoon circulation.
|
| Descriptor
|
:
|
Atmospheric sciences
|
|
|
:
|
Climate change
|
|
|
:
|
Geography
|
| Added Entry
|
:
|
Sheridan, Scott
|
| Added Entry
|
:
|
Kent State University
|
| |