http://nopr.niscair.res.in/handle/123456789/1491 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/4168 Title: Impact of satellite derived wind in mesoscale simulation of Orissa super cyclone <br/> <br/>Authors: Mandal, M.; Mohanty, U. C.; Das, A. K. <br/> <br/>Abstract: Prediction of track and intensity of tropical cyclones is one of the most challenging problems in numerical weather prediction (NWP). Providing reasonably accurate initial condition to tropical cyclone forecast models has always been a problem to numerical weather forecasters. Recent advancements in spatial resolution and radiometric sensitivity have significantly improved the accuracy and density of satellite derived wind. The objective of the present study is to examine the impact of satellite derived winds in improving model initial condition and hence in mesoscale simulation of cyclonic storm. In this study, PSU/NCAR mesoscale model MM5 is used to produce 5-day simulation of the super cyclone that crossed Orissa coast on 29 October 1999. Winds derived from QSCAT, SSM/I, MSMR and METEOSAT-5 satellites are used in preparation of high-resolution reanalysis (HRR) and improving model initial condition. The strength of the southwesterly wind (over ocean) converging to the storm is found to be stronger both in the HRR and improved model initial condition compared to that in the NCEP/NCAR reanalysis. The strength of the cyclonic vortex is also better represented in the HRR and improved model initial condition. Improvement in model initial condition has resulted in consistent and significant improvement (35% in average) in prediction of the track of the storm. <br/> <br/>Page(s): 161-173 http://nopr.niscair.res.in/handle/123456789/1514 Title: A study on cyclone induced productivity in south-western Bay of Bengal during November-December 2000 using MODIS (SST and chlorophyll-a) <br/> <br/>Authors: Rao, K. H.; Smitha, A.; Ali, M. M. <br/> <br/>Abstract: MODIS (Moderate Resolution Imaging Spectroradiometer) on board TERRA weekly composite mean products of sea surface temperature (SST) and chlorophyll-a, and modeled ocean net primary productivity with a spatial resolution of 4.63 km and altimeter derived sea surface height (SSH) data are used to study the changes in the primary productivity (PP) induced by the November-December 2000 tropical cyclone in the Bay of Bengal. A maximum SST drop of 2ºC, a sea surface depression of 10 cm compared to the periphery, increase in chlorophyll-a by 1.5 mg/m³ and enhanced average mixed PP of 964 gC/m²/y were observed around 11.0ºN and 81.0ºE after the passage of the cyclonic storm. The enhanced PP after the passage of the cyclone supports the base of the pelagic marine food web, directly affecting the fishery productivity. <br/> <br/>Page(s): 153-160 http://nopr.niscair.res.in/handle/123456789/1513 Title: Observations and numerical simulation of the sea and land breeze circulations along the west coast of India <br/> <br/>Authors: Simpson, M. D.; S., Raman <br/> <br/>Abstract: Sea breeze circulation along the west coast of India during the Indian Ocean Experiment (1999) is investigated. Pilot balloon sounding data from Mumbai, Goa, and Trivandrum, India show a diurnal variation in wind direction caused by land and sea breeze circulations along the west coast of India. Rawinsonde wind profiles taken from R/V Sagar Kanya 130 km offshore from the west coast of India show the presence of sea and land breeze circulations. Infrared satellite images show the furthest extent of the sea breeze circulation over the Arabian Sea to be around 200 km. Constant level balloons released from Goa, India also showed the extent of the sea breeze over the ocean to be 200 km. A mesoscale numerical model was used to further investigate the sea breeze circulation and its horizontal extent over the ocean. Simulated cross sections along the west coast of India show the horizontal extent of the afternoon sea breeze over the ocean to vary from around 130 to 260 km. Vertical velocities of about 0.25 ms⁻¹ were simulated inland as the sea breeze interacted with the mountains along India’s west coast. <br/> <br/>Page(s): 139-152 http://nopr.niscair.res.in/handle/123456789/1512 Title: Estimation of tropical cyclone heat potential in the Bay of Bengal and its role in the genesis and intensification of storms <br/> <br/>Authors: Sadhuram, Y.; Murthy, T.V.Ramana <br/> <br/>Abstract: In the present study, cyclone heat potential (CHP) in the Bay of Bengal has been estimated for different seasons using Levitus climatology. A good association was noticed between CHP and the efficiency of intensification (i.e the ratio between severe storms to total number of storms (in 5º × 5º grid), for the period, 1877-1977. CHP has been estimated using CTD data collected along the transects 88° E (4º -20º N) and 11.5º N (81º -92º E) during 1993-96 under pre-, during and post- SW monsoon seasons. These estimates are compared with those obtained from TOPEX/Poseidon sea surface height anomalies (SSHA) and TMI (Tropical Rainfall Measuring Mission Microwave Imager) SST using a two layer gravity model. The above estimates are also compared in the Andaman Sea for the 1996 post– SW monsoon season. It appears that the later method underestimates the CHP in the regions of anti cyclonic gyre (ACG). A relation between CHP and SSHA is proposed for the Bay of Bengal which shows a high correlation of 0.79 (N= 67; significant at > 99% level) using the CTD data. <br/> <br/>Page(s): 132-138