On the gross predictability of tropical monsoonal depressions

Rao, Sankar M and Goswami, Prashant and Upadhyaya, Nagaraj HV (1991) On the gross predictability of tropical monsoonal depressions. In: Proceedings of the Indian Academy of Science: Earth and Planetary Sciences, 100 (2). pp. 127-144.

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Abstract

The experiments reported here emphasize the importance of observations in the prediction of tropical cyclones. Towards this end a symmetric numerical model in which convection, parametrized by the Arakawa-Schubert (AS) scheme, was adopted. A mean thermodynamical state, which represents the monsoon conditions over the Bay of Bengal, with constant moist static energy for the mixed layer was adopted. Experiments were then done with different initial conditions. We found that tropical cyclone development measured by the central pressure was very sensitive to the initial convergence field. In the present state of satellite technology, it was impossible to predict even a gross parameter like the central pressure with an accuracy better than 6mb for 12 hours. However, it was seen that under a variety of initial conditions the final state characterized by the magnitude of the central low pressure remained practically unaltered. We suggest that, given the necessary conditions for genesis, the final state of the cyclone acts as an attractor (regarding its central pressure) and the diverse initial conditions, under the influence of thermodynamic forcing, will lead to the same final state.

Item Type:	Journal Article
Publication:	Proceedings of the Indian Academy of Science: Earth and Planetary Sciences
Publisher:	Indian Academy of Sciences
Additional Information:	Copyright of this Article belongs to Indian Academy of Science.
Keywords:	Cyclones;Prediction;Convective parametrization;Central pressure;Physical model;Numerical model
Department/Centre:	Division of Mechanical Sciences > Aerospace Engineering(Formerly Aeronautical Engineering) Division of Mechanical Sciences > Centre for Atmospheric & Oceanic Sciences
Date Deposited:	03 Nov 2006
Last Modified:	19 Sep 2010 04:32
URI:	http://eprints.iisc.ac.in/id/eprint/8710

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