Open AccessOn the planetary scale changes during the summer monsoon 1979
Author(s) -
Y. Ramanathan
Publication year - 1986
Publication title -
mausam
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.243
H-Index - 12
ISSN - 0252-9416
DOI - 10.54302/mausam.v37i4.2564
Subject(s) - climatology , orographic lift , monsoon , latitude , atmospheric sciences , geology , maxima , middle latitudes , forcing (mathematics) , environmental science , geography , meteorology , geodesy , precipitation , art , performance art , art history
FGGE III-b data sets for June 1979 were used to study the planetary scale changes in the upper and lower tropospheres during the onset phase of the Asiatic summer monsoon. The largest contribution to the variance of the zonal wind at the latitude of the low level jet at 850mb was from the wave number one. This appeared to be in response to the re-distribution] of the latent heating fields in the equatorial Indian Ocean region in the onset phase when a prominent heat source region appeared around 70"E and extended northwards and westwards. At 300mb significant changes preceded the onset in the middle latitude planetary scales. The wave numbers one and two weakened and their amplitude maxima shifted polewards and eastwards. The wave number three appeared to be largely due to orographic forcing.