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Kumar M. Dinesh Tandon Shubham Bassi Nitin Mohanty Pradipta Kumar Kumar Saurabh Mohandas Manish 《Natural Hazards》2022,110(3):2035-2057
Natural Hazards - Many coastal cities in developing countries are at the risk of flooding due to a progressive increase in the built-up areas and poor management of storm water. The flooding... 相似文献
2.
There have been very few mesoscale modelling studies of the Indian monsoon, with focus on the verification and intercomparison
of the operational real time forecasts. With the exception of Das et al (2008), most of the studies in the literature are either the case studies of tropical cyclones and thunderstorms or the sensitivity
studies involving physical parameterization or climate simulation studies. Almost all the studies are based on either National
Center for Environmental Prediction (NCEP), USA, final analysis fields (NCEP FNL) or the reanalysis data used as initial and
lateral boundary conditions for driving the mesoscale model. 相似文献
3.
Someshwar Das Raghavendra Ashrit Gopal Raman Iyengar Saji Mohandas M. Das Gupta John P. George E. N. Rajagopal Surya Kanti Dutta 《Journal of Earth System Science》2008,117(5):603-620
Performance of four mesoscale models namely, the MM5, ETA, RSM and WRF, run at NCMRWF for short range weather forecasting has been examined during monsoon-2006. Evaluation is carried out based upon comparisons between observations and day-1 and day-3 forecasts of wind, temperature, specific humidity, geopotential height, rainfall, systematic errors, root mean square errors and specific events like the monsoon depressions.It is very difficult to address the question of which model performs best over the Indian region? An honest answer is ‘none’. Perhaps an ensemble approach would be the best. However, if we must make a final verdict, it can be stated that in general, (i) the WRF is able to produce best All India rainfall prediction compared to observations in the day-1 forecast and, the MM5 is able to produce best All India rainfall forecasts in day-3, but ETA and RSM are able to depict the best distribution of rainfall maxima along the west coast of India, (ii) the MM5 is able to produce least RMSE of wind and geopotential fields at most of the time, and (iii) the RSM is able to produce least errors in the day-1 forecasts of the tracks, while the ETA model produces least errors in the day-3 forecasts. 相似文献
4.
S. Das A. K. Mitra G. R. Iyengar S. Mohandas 《Meteorology and Atmospheric Physics》2001,78(3-4):227-244
Summary
The global spectral model of NCMRWF at T80 horizontal resolution and 18 vertical levels has been integrated for the summer
season (July) using different cumulus parameterization schemes namely, the Simplified Arakawa-Schubert scheme (SAS), the Relaxed
Arakawa-Schubert Scheme (RAS), and the Kuo-type cumulus parameterization scheme (KUO). The results have been compared with
mean analysis of the operational NCMRWF model (ANA) and other available observations.
Results indicate that, while the global distributions of basic fields such as the wind, temperature and moisture are fairly
well simulated by all the three schemes, there are many differences seen in the simulation of the typical features of the
Indian summer monsoon. The strength of the Low Level Westerly Jet (LLWJ), the Cross Equatorial Flow (CEF), and the Tropical
Easterly Jet (TEJ) are better simulated by RAS and SAS as compared to ANA than the KUO scheme. RAS and SAS produce strong
rising motion owing to strong intensity of convection produced by these two schemes. This in turn produces stronger Hadley
cell by RAS and SAS than compared to the KUO scheme. Simulation of the 200 mb velocity potential and divergent wind by RAS
and SAS produced two prominent centers, one in the Bay of Bengal and another in the Western Pacific, which correspond to the
intense latent heating by cumulus convection during the active monsoon phase. The velocity potential and divergent winds were
weaker in KUO, than compared to RAS and SAS.
The simulation of OLR is improved by RAS as compared to observations. The cold bias produced by KUO at 200 mb is reduced by
RAS and is substantially improved by SAS. Study of observed and simulated rainfall indicated that RAS and SAS produced better
distribution of precipitation over the Western Ghat Mountains and the Arakan coast, where deep cumulus convection is produced
due to orographic forcing of the warm moist air. The KUO scheme underestimated the rainfall over these two regions, but produced
slightly better distribution of rainfall over the northwest and central India, where the intensity of convection is relatively
weaker.
Evaluation of overall dynamics, thermal structure and rainfall indicates that in general, SAS is able to provide relatively
better results compared to other two schemes.
Received October 3, 2000/Revised December 5, 2000 相似文献
5.
Solar evaporation studies of subsoil brines from three different locations of Gujarat State in India were undertaken. Evaporation
of brines from their initial densities to 29-30°Be’ density was studied and the data were compared with those of sea brine.
From the experimental data, the change in the quality of salts crystallized at various density levels with changing ionic
composition of brines is explained theoretically and the ionic composition of an ideal brine and proper density ranges for
the recovery of high quality salt are identified.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
6.
Application of primary haemocyte culture of Penaeus monodon in the assessment of cytotoxicity and genotoxicity of heavy metals and pesticides 总被引：1，自引：0，他引：1
Jose S Jayesh P Mohandas A Philip R Bright Singh IS 《Marine environmental research》2011,71(3):169-177
Lack of shrimp cell lines has hindered the study of pollutants which adversely affects shrimp health and its export value. In this context a primary haemocyte culture developed from Penaeus monodon was employed for assessing the cytotoxicity and genotoxicity of two heavy metal compounds, cadmium chloride and mercuric chloride and two organophosphate insecticides, malathion and monocrotophos. Using MTT assay 12?h IC(50) values calculated were 31.09?±?16.27?μM and 5.52?±?1.16?μM for cadmium chloride and mercuric chloride and 59.94?±?52.30?mg?l(-1) and 186.76?±?77.00?mg?l(-1) for malathion and monocrotophos respectively. Employing Comet assay, DNA damage inflicted by these pollutants on haemocytes were evaluated and the pollutants induced DNA damage in >60% of the cells. The study suggested that haemocyte culture could be used as a tool for quantifying cytotoxicity and genotoxicity of aquaculture drugs, management chemicals and pollutants. 相似文献
7.
C K Unnikrishnan John P George Abhishek Lodh Devesh Kumar Maurya Swapan Mallick E N Rajagopal Saji Mohandas 《Journal of Earth System Science》2016,125(5):935-944
Surface level soil moisture from two gridded datasets over India are evaluated in this study. The first one is the UK Met Office (UKMO) soil moisture analysis produced by a land data assimilation system based on Extended Kalman Filter method (EKF), which make use of satellite observation of Advanced Scatterometer (ASCAT) soil wetness index as well as the screen level meteorological observations. Second dataset is a satellite soil moisture product, produced by National Remote Sensing Centre (NRSC) using passive microwave Advanced Microwave Scanning Radiometer 2 measurements. In-situ observations of soil moisture from India Meteorological Department (IMD) are used for the validation of the gridded soil moisture products. The difference between these datasets over India is minimum in the non-monsoon months and over agricultural regions. It is seen that the NRSC data is slightly drier (0.05%) and UKMO soil moisture analysis is relatively wet during southwest monsoon season. Standard AMSR-2 satellite soil moisture product is used to compare the NRSC and UKMO products. The standard AMSR-2 and UKMO values are closer in monsoon season and AMSR-2 soil moisture is higher than UKMO in all seasons. NRSC and AMSR-2 showed a correlation of 0.83 (significant at 0.01 level). The probability distribution of IMD soil moisture observation peaks at 0.25 m3/m3, NRSC at 0.15 m3/m3, AMSR-2 at 0.25 m3/m3 and UKMO at 0.35 m3/m3 during June–September period. Validation results show UKMO analysis has better correlation with in-situ observations compared to the NRSC and AMSR-2 datasets. The seasonal variation in soil moisture is better represented in UKMO analysis. Underestimation of soil moisture during monsoon season over India in NRSC data suggests the necessity of incorporating the actual vegetation for a better soil moisture retrieval using passive microwave sensors. Both products have good agreement over bare soil, shrubs and grassland compared to needle leaf tree, broad leaf tree and urban land cover types. 相似文献
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