IITM Publication Highlights


Shape and oscillations of the water drops freely suspended in a horizontal electric field: A wind tunnel study

This experimental study presents the distortion, frequency and amplitude of oscillations of water drops by suspending them in a vertical wind tunnel in the presence and absence of horizontal electric fields using a high speed camera at 1000 frames/sec. It demonstrates the pronounced drop distortion with increase in horizontal electric field resulting in its instability at 6.6 mm. Although, there is no significant change in oscillation frequency, the amplitude of oscillation is reduced with electric field ≤ 500 kV m-1. The possible effects of electrical forces on shape parameters and their implications on cloud microphysics and in radar meteorology are discussed. Read more... (Bhalwankar R., Deshpande C.G. and Kamra A.K., J. of Atm. & Solar-Terrestrial Phy., Sept. 2015)

Diagnosis of boreal summer intraseasonal oscillation in high resolution NCEP climate forecast system

The present study examines the ability of high resolution (T382) National Centers for Environmental Prediction coupled atmosphere-ocean climate forecast system version 2 (CFS T382) in simulating the salient spatio-temporal characteristics of the boreal summertime mean climate and the intraseasonal variability. Based on analysis of CCEWs, the study further explains the possible reasons behind the realistic simulation of northward propagating BSISO in CFS T382, even though the model shows substantial biases in simulating mean state and otherBSISO modes. Read more... (Abhik S., Mukhopadhyay P., R.P.M. Krishna, Salunke K.D., Dhakate A.R., Suryachandra A. Rao, Climate Dynamics, Online, August 2015)

Improved Spread-Error Relationship and Probabilistic Prediction from the CFS-Based Grand Ensemble Prediction System

This study describes an attempt to overcome the under-dispersive nature of single-model ensembles (SMEs). As an Indo-U.S. collaboration designed to improve the prediction capabilities of models over the Indian monsoon region in the framework of the National Centers for Environmental Predictions-Climate Forecast System (NCEP-CFSv2) model, a CFS based Grand Multi Model Ensemble Prediction System (CGMME) has been developed at IITM. Statistical skill of this CFS-based Grand Ensemble Prediction System (CGEPS) is better than the best participating SME configuration, because increased ensemble spread reduces overconfidence errors. The results encourage IITM to pursue first time implementation of operational extended-range prediction of the Indian summer monsoon. Read more... (Abhilash S., Sahai A.K., Borah N., Joseph S., Chattopadhyay R., Sharmila S., Rajeevan M., et al, J. Applied Met. & Climatology, July 2015)

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