Simulation for the South China Sea Monsoon Onset Base on Grapes Model and Experiment for the Model Initial Fields
Abstract
Generally speaking, the South China Sea summer monsoon(SCSSM) onset marks the arrival of the East and Southeast Asian summer monsoon and the beginning of the major rainy season in these regions. Therefore, the correct simulation of SCSSM has a significant implication. It is simulated and forecast by GRAPES model in this paper. Aimed to the condition that model initial fields in model is weaker,we improve the model initial fields by Using the AMSU-B data of NOAA17 planet. Two schemes is applied to test: Test 1 (T1) both sounding and AMSU-B data are assimilated and test 2 (T2) only sounding data is assimilated by GRAPES three-dimensional variational data assimilation system.Comparative experiments show that the model is very sensitive to the change of model initial fields . the model with assimilation T2 scheme well simulates the process of the SCSSM onset reasonably well, which can reproduce the onset timing and dramatic changes before and after the SCSSM onset, especially the upper and lower level flow patterns. For the abnormity of precipitation and location of the subtropical high, there are still some biases between the simulations and the observations including the location of the subtropical high simulated further north and west, the precipitation amount over the south China Sea too much as well as the range of precipitation too broad.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2010
- Bibcode:
- 2010AGUFM.A33B0161Z
- Keywords:
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- 0325 ATMOSPHERIC COMPOSITION AND STRUCTURE / Evolution of the atmosphere