Publication

The impact of assimilation of AMSU data for the prediction of a tropical cyclone over India using a mesoscale model


Publication Date : 2007-02-22
Author : Sandeep, S.Chandrasekar, A.Singh, D.
Countries :
Disaster Management Theme :
Disaster Type : Tropical Cyclone
Document Type : Research Paper
Languange : en
Link : http://www.tandfonline.com/doi/abs/10.1080/01431160600857410

Abstact :

Tropical cyclones form over the seas: a typical data-sparse region for conventional observations. Therefore, satellites, especially with microwave sensors, are ideal for cyclone studies. The advanced microwave sounding unit (AMSU) , in addition to providing very valuable data over non-precipitating cloudy regions, can provide very high horizontal resolution of the temperature and humidity soundings. Such high-resolution microwave data can improve the poorly analysed cyclone. The objective of this study is to investigate the impact of ingesting and assimilating the AMSU data together with conventional upper air and surface meteorological observations over India on the prediction of a tropical cyclone which formed over the Arabian Sea during November 2003 using analysis nudging. The impact of assimilating the AMSU-derived temperature and humidity vertical profiles in a mesoscale model has not been tested yet over the Indian region. Such studies are important as most weather systems over India form over the seas. The present study is unique in the sense that it addresses the impact of ingesting and assimilating microwave sounding data (together with conventional India Meteorological Department data) on the prediction of a tropical cyclone, which formed over the Arabian Sea during November 2003 using analysis nudging. Two sets of numerical experiments are designed in this study. While the first set utilizes the National Center for Environmental Prediction (NCEP) reanalysis (for the initial and lateral boundary conditions) only in the fifth-generation mesoscale model simulation, the second set utilized the AMSU satellite and conventional meteorological upper air and surface data to provide an improved analysis through analysis nudging. The results of the two sets of model simulations are compared with one another as well as with the NCEP reanalysis and the observations.