NOPR Community:

Book Review

Mon, 01 Dec 2003 00:00:00 GMT

Title: Book Review Abstract: Indian estuaries by S.Z. Qasim
A. Rajendran Page(s): 348-350

Indian Ocean dipole mode events in a simple mixed layer ocean model

Mon, 01 Dec 2003 00:00:00 GMT

Title: Indian Ocean dipole mode events in a simple mixed layer ocean model Authors: Gnanaseelan, C.; Chowdary, J. S.; Mishra, A. K.; Salvekar, P. S. Abstract: A precise knowledge of sea surface temperature (SST) is very essential for climate and oceanographic studies. In this paper a simple two dimensional mixed layer ocean model and its numerical code have been developed and used to simulate the SST fields over the north Indian Ocean (20°S-25°N and 35°E-115°E) for a period of 10 years (1992-2001). The model simulated the SST variability reasonably well. The simple model could simulate the observed dipole of 1997 and 1994 very well, especially the eastern cooling. The model study showed that the interannual SST variability in the western equatorial Indian Ocean is not only due to the variability in the surface heat fluxes, but also due to the variability in wind and sea surface height (SSH). The OLR anomaly also shows positive (negative) anomaly over the negative (positive) anomalous SST region. The variability in the latent heat flux is found to be greatly influencing the SST variability in the eastern equatorial Indian Ocean. Page(s): 294-304

Water repellent treatments for catamaran grade Bombax ceiba Linn. (Spermatophyta/Dicotyledoneae) wood

Mon, 01 Dec 2003 00:00:00 GMT

Title: Water repellent treatments for catamaran grade Bombax ceiba Linn. (Spermatophyta/Dicotyledoneae) wood Authors: Aggarwal, Pankaj K.; Chauhan, S. S.; Prasad, N. R. R.; Rao, K. S. Abstract: Water repellency effectiveness (WRE) of four chemical formulations, namely polymeric methylene diisocyanate (PMDI), cashew nut shell oil (CSNL), varnish and chromium trioxide, was assessed on Cooper-Chrome-Arsenic (CCA) treated Bombax ceiba wood. Fifteen cycles of repeated wetting and drying were performed on water repellent coated and untreated wood. Water repellency was very high in the first cycle and then declined in all the coating system in subsequent cycles. After 10^th cycle WRE became constant for all the systems. PMDI exhibited highest water repellency followed by chromium trioxide, CSNL and varnish. With the application of water repellent formulations, water uptake can be reduced considerably, which will maintain buoyancy of wood. The water repellents apart from reducing water holding capacity also reduces leaching of preservatives from the structures, which resulted in enhancing the durability of wood. Page(s): 340-343

Statistical forecasting of met-ocean parameters in the Cochin estuarine system, southwest coast of India

Mon, 01 Dec 2003 00:00:00 GMT

Title: Statistical forecasting of met-ocean parameters in the Cochin estuarine system, southwest coast of India Authors: Srinivas, K.; Revichandran, C.; Kumar, P. K. Dinesh Abstract: Three different statistical forecasting techniques - autoregressive, sinusoidal and exponentially weighted moving average (EWMA) were used to forecast monthly values of meteorological and oceanographic (met-ocean) parameters viz. sea surface temperature (SST), air temperature, atmospheric pressure, wind speed, rainfall, relative density and sea level, in the Cochin estuarine system. The EWMA technique (which yields forecast with a lead time of only one month) gave the lowest root mean square errors relative to the verifying observations. Atmospheric pressure could be forecast with less than 5% of error while SST and air temperature with less than 10% of error, by all the three techniques. 80% of the time, sea level could be forecast with less than 10% error, by each of the three techniques. However, wind speed, relative density and rainfall could not be forecast by any of the three techniques with any acceptable degree of accuracy. Page(s): 285-293