Abstracts for the 5th International GAME Conf.
3-5 October 2001
Aichi Trade Center
Nagoya Japan
Monsoon Rainfall Variability over South and East Asia: Impact of Snow Cover
R.H.Kripalani (1), Ashwini Kulkarni (1), Baek-Jo Kim (3), Jai-Ho Oh (3)
(1) Indian Institute of Tropical Meteorology, Pune, India
(3) Meteorological Research Institute, KMA, Seoul, Korea
Land-atmosphere interactions play an important role in the monsoon variability over the Asian domain. The adverse impact of Himalayan/Eurasian snow on Indian Monsoon Rainfall has been well documented by Blanford more than 100 years ago. Studies have also shown the impact of Tibetan Plateau snow on monsoon variability over China, however the results are complicated suggesting that smaller areas over East Asia need to be considered. Recently the Historical Soviet Snow Depth data product for the period 1881-1994(Version 1) has been developed under the bilateral data exchange agreement between USA and former USSR. This study uses this data to examine the impact of snow on monsoon variability over India and Korea.
The connections between the winter Soviet snow depth and the summer monsoon rainfall over south Asia (in particular India) and east Asia (in particular South Korea) has been investigated by lag correlation coefficients and composite analysis. Results reveal that winter-time snow depth surrounding Moscow (central Siberia) is negatively (positively) related with subsequent Indian monsoon rainfall. While for South Korea, the snow depth over Kazakhstan (eastern Siberia) is negatively (positively) related with subsequent rainfall. Thus for both the regions a dipole correlation configuration is depicted. The only difference being that for east Asia the dipole pattern is shifted east by about 30-40 degrees of longitude.
To examine the circulation features associated with the dipole correlation structure NCEP/NCAR Reanalyses data product is used. The dipole correlation structure is indicative of a mid-latitude long-wave pattern with an anomalous ridge (trough) over north Asia prior to a strong (weak) south Asian monsoon. On the other hand it is indicative of an anomalous trough (ridge) prior to a strong (weak) east Asian (ie. South Korea) monsoon. Thus the winter–time flow patterns over north Asia are remarkably reverse for similar extreme monsoon situations over India and South Korea. This further implies that the summer monsoon rainfall activity over India and South Korea is negatively related.
(Part of the work was done at the Forecast Research Laboratory, Meteorological Research Institute, Korea Meteorological Administration, Seoul, South Korea during the visit of the first author-July to Dec 2000-supported by the Brain Pool Program launched by the Korean Federation of Science and Technology Societies).
Submittal Information
| Name : | Date : |
| |
| Organization : | Theme : |
Indian Institute of Tropical Meteorology | |
| Address : | Presentation : |
Dr. Homi Bhabha Road, Pashan, /Pune-411 008 | |
| Country : | Abstract ID : |
| |
| Phone : | Fax : |
| |
| E-mail : | |
| |