Variability of Convective Activity over the North Indian Ocean and its Associations with Monsoon Rainfall over India

2008 ◽  
pp. 1527-1545
Author(s):  
D. R. Pattanaik
Keyword(s):  
Indian Ocean ◽  
Monsoon Rainfall ◽  
North Indian Ocean ◽  
Convective Activity ◽  
The North

scholarly journals Principal component analysis of monthly mean Area surface temperature over the Arabian Sea, Bay of Bengal and north Indian Ocean for two Contrasting sets of monsoon years

MAUSAM ◽  
2021 ◽  
Vol 44 (1) ◽  
pp. 69-76
Author(s):  
T. K. BALAKRISHNAN ◽  
A. K. JASWAL ◽  
S.S.. SINGH ◽  
H. N. SRIVASTAVA
Keyword(s):  
Indian Ocean ◽  
Bay Of Bengal ◽  
Arabian Sea ◽  
Monsoon Rainfall ◽  
Equatorial Indian Ocean ◽  
Principal Component ◽  
North Indian Ocean ◽  
Orthogonal Function ◽  
The North ◽  
Extreme North

The spatial distribution and temporal variation of the monthly mean SSTA over the Arabian Sea, Bay of Bengal and the north Indian Ocean were investigated for a set of contrasting years of monsoon over the period 1961-80 for months April through July using Empirical Orthogonal Function (EOF) technique with a view to identify regions that are significantly related to the monsoon rainfall. Over 75% of the total variance is, explained by the first mode EOF. SSTA over the north and northeast Arabian Sea during pre-monsoon months were found to be possible indicators of the ensuing monsoon activity. The higher eigen vectors in May over northeast Arabian Sea may signal good monsoon and vice versa. In June there is a marked contrast in the distribution of SST over the Arabian Sea between the two sets of the years the eastern Arabian Sea IS warmer for the deficient monsoon years while the entire Arabian Sea except over the extreme north Arabian Sea is cool during good monsoon years. There is formation of SSTA over the equatorial Indian Ocean area close to Indonesian island commencing from May which is more marked in June and is positively correlated with seasonal rainfall activity over India.  

scholarly journals A diagnostic study of interannual variability of Indian summer monsoon using outgoing longwave radiation (OLR) data

MAUSAM ◽  
2021 ◽  
Vol 48 (1) ◽  
pp. 55-64
Author(s):  
D.S. PAI
Keyword(s):  
Indian Ocean ◽  
Outgoing Longwave Radiation ◽  
Equatorial Indian Ocean ◽  
Longwave Radiation ◽  
Walker Circulation ◽  
North Indian Ocean ◽  
Diagnostic Study ◽  
Convective Activity ◽  
The North ◽  
Convective Pattern

ABSTRACT. Using the monthly outgoing longwave radiation (OLR) data obtained from NOAA polar orbiting satellites, during the period 1979-92, composite OLR anomalies in respect of good monsoon years (1983 and 1988), bad monsoon years (1982 and 1987 for the case associated with ENSO and 1979 and 1986 separately for the case without ENSO) and normal monsoon years (1980, 1981, 1984, 1985, 1989, 1990, 1991 & 1992) were examined. The computation has been performed over the global tropics (30°N-30°S) bounded between the longitudes 50°E and 130°W (through date line) on 5° longitude × 5° latitude grid. There are significant differences in the spatial distributions of composite OLR anomalies between these four cases from the month of April to September indicating spatial and temporal changes in the organized convective pattern. For the good monsoon years persistent negative anomalies indicating enhanced convective activity were observed over the Indonesian regions, whereas large positive anomalies indicating depressed convective activity were observed over equatorial Pacific just west of date line. During the bad monsoon years above normal convection was observed over Pacific region (ENSO case) and over equatorial Indian Ocean (Non ENSO case). During normal monsoon years the spatial patterns of OLR anomalies were similar to that of good monsoon years, but with weaker anomalies. These observations can be explained through the relative interaction between tropical convergence zone (TCZ) over the Indian sub-continent and that over the north Indian Ocean and Pacific. The eastward shift of the convective activity during El-Nino years can be attributed to shift/reversal of Walker circulation. There are strong signals of OLR anomalies during pre-monsoon months which may be useful in inferring the nature of the subsequent monsoon activity.  

scholarly journals The association between the north Indian Ocean and summer monsoon rainfall over India

MAUSAM ◽  
2021 ◽  
Vol 49 (3) ◽  
pp. 325-330
Author(s):  
O. P. SINGH
Keyword(s):  
Indian Ocean ◽  
Summer Monsoon ◽  
Arabian Sea ◽  
Monsoon Rainfall ◽  
Monsoon Season ◽  
Meteorological Data ◽  
Summer Monsoon Rainfall ◽  
North Indian Ocean ◽  
The North ◽  
The Mean

Utilizing the marine meteorological data of the period 1961-81, the sea level pressure (SLP) and sea surface temperature (SST) distributions have been obtained on a 5° grid-mesh over the north Indian Ocean area bounded by  0°- 25°N, 50°- l00°E for each individual year. It has been found that the SLP and SST fields for the month of May provide predictive indications of subsequent summer monsoon rainfall over India. Significant negative correlations have been found between the mean SLPs of May over the latitudinal belts 5°-10°, 10°- 15°, 15°-20° and 20°-25°N of Arabian Sea and Bay of Bengal and all India rainfall departures of succeeding summer monsoon season. The mean SST gradient over the Arabian Sea between 7.5°- 17 .5°N during May has been found to have significant positive correlation with all India rainfall of subsequent monsoon. The study suggests that certain functions of SLP and SST of May over the north Indian Ocean can prove to be useful predictors for subsequent summer monsoon rainfall over India.

scholarly journals An oceanic model for the prediction of southwest monsoon rainfall over India

MAUSAM ◽  
2021 ◽  
Vol 47 (1) ◽  
pp. 91-98
Author(s):  
J. P. SlNGH ◽  
D. S. PAI
Keyword(s):  
Indian Ocean ◽  
Regression Model ◽  
Summer Monsoon ◽  
Arabian Sea ◽  
Monsoon Rainfall ◽  
Principal Component ◽  
Southwest Monsoon ◽  
Summer Monsoon Rainfall ◽  
North Indian Ocean ◽  
The North

Nine new oceanic predictor for long range forecasting of Indian summer monsoon rainfall been identified utilizing  the marine meteorological data of the North Indian Ocean and the monsoon rainfall data of the period 1961-91. In order to develop a reliable regression model the principal component analysis (PCA) of original variables has been done. Five parameters having maximum influence on first principal component, which is having highest correlation with the monsoon rainfall are : wind power in the atmospheric boundary layer over the north Indian Ocean between Equator and 100 N, mean evaporation over the Arabian Sea (00 -150 N) mean sea surface temperature (SST) gradient over the Arabian Sea between 7.50 – 17.50 N, mean evaporation over Bay of Bengal between Equator and 100 N and mean sea level pressure (SLP) over the Arabian Sea, each pertaining to the month of May. A multiple regression model for all Indian rainfall of southwest monsoon season has been developed using the principal components which have got good cor-relations with the monsoon rainfall. The model was tested for all the years from 1987 to 1991 and it has been found that the predicted values of all India summer monsoon rainfall of all the years except 1989 were very close to the actual values. However, there was a substantial difference between the predicted and actual rainfall of 1989 summer monsoon.

scholarly journals Design of Wave Glider Optimal Parameters Suitable for the Northwest Pacific Ocean, the North Indian Ocean, and the South China Sea

2021 ◽  
Vol 9 (4) ◽  
pp. 408
Author(s):  
Xi Chen ◽  
Mei Hong ◽  
Shiqi Wu ◽  
Kefeng Liu ◽  
Kefeng Mao
Keyword(s):  
Indian Ocean ◽  
South China Sea ◽  
South China ◽  
North Indian Ocean ◽  
Northwest Pacific ◽  
Northwest Pacific Ocean ◽  
The North ◽  
Wave Element ◽  
Wave Glider ◽  
The Northwest Pacific Ocean

To study the optimal design of Wave Glider parameters in the wave environment of the Northwest Pacific Ocean, the North Indian Ocean, and the South China Sea, the average velocity of a Wave Glider was taken as the evaluation criterion. Wave reanalysis data from ERA5 were used to classify the mean wave height and period into five types by the K-means clustering method. In addition, a dynamic model was used to simulate the influence of umbilical length, airfoil, and maximum limited angle on the velocity of the Wave Glider under the five types of wave element. The force of the wings was simulated using FLUENT as the model input. The simulation results show that (1) 7 m is the most suitable umbilical length; (2) a smaller relative thickness should be selected in perfect conditions; and (3) for the first type of wave element, 15° is the best choice for the maximum limited angle, and 20° is preferred for the second, third, and fourth types, while 25° is preferred for the fifth type.

Extended Prediction of North Indian Ocean Tropical Cyclones

2012 ◽  
Vol 27 (3) ◽  
pp. 757-769 ◽  
Author(s):  
James I. Belanger ◽  
Peter J. Webster ◽  
Judith A. Curry ◽  
Mark T. Jelinek
Keyword(s):  
Tropical Cyclone ◽  
Indian Ocean ◽  
Tropical Cyclones ◽  
North Indian Ocean ◽  
Ensemble Prediction ◽  
Tropical Cyclone Genesis ◽  
Lead Times ◽  
Prediction System ◽  
Ensemble Prediction System ◽  
The North

Abstract This analysis examines the predictability of several key forecasting parameters using the ECMWF Variable Ensemble Prediction System (VarEPS) for tropical cyclones (TCs) in the North Indian Ocean (NIO) including tropical cyclone genesis, pregenesis and postgenesis track and intensity projections, and regional outlooks of tropical cyclone activity for the Arabian Sea and the Bay of Bengal. Based on the evaluation period from 2007 to 2010, the VarEPS TC genesis forecasts demonstrate low false-alarm rates and moderate to high probabilities of detection for lead times of 1–7 days. In addition, VarEPS pregenesis track forecasts on average perform better than VarEPS postgenesis forecasts through 120 h and feature a total track error growth of 41 n mi day−1. VarEPS provides superior postgenesis track forecasts for lead times greater than 12 h compared to other models, including the Met Office global model (UKMET), the Navy Operational Global Atmospheric Prediction System (NOGAPS), and the Global Forecasting System (GFS), and slightly lower track errors than the Joint Typhoon Warning Center. This paper concludes with a discussion of how VarEPS can provide much of this extended predictability within a probabilistic framework for the region.

scholarly journals Role of the ITCZ over the North Indian Ocean and Pre-Mei-Yu Front in Modulating July Rainfall over India

2004 ◽  
Vol 17 (3) ◽  
pp. 673-678 ◽  
Author(s):  
A. K. Srivastava ◽  
M. Rajeevan ◽  
S. R. Kshirsagar
Keyword(s):  
Indian Ocean ◽  
North Indian Ocean ◽  
The North
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