scholarly journals Northeast monsoon rainfall variability over south peninsular India vis-à-vis the Indian Ocean dipole mode

2004 ◽  
Vol 24 (10) ◽  
pp. 1267-1282 ◽  
Author(s):  
R. H. Kripalani ◽  
Pankaj Kumar
Keyword(s):  
Indian Ocean ◽  
Indian Ocean Dipole ◽  
Monsoon Rainfall ◽  
Rainfall Variability ◽  
Northeast Monsoon ◽  
Dipole Mode ◽  
Peninsular India ◽  
Indian Ocean Dipole Mode ◽  
Northeast Monsoon Rainfall ◽  
The Indian Ocean

scholarly journals District-level forecast of northeast monsoon rainfall over Tamilnadu using Indian Ocean dipole mode index

MAUSAM ◽  
2021 ◽  
Vol 62 (2) ◽  
pp. 229-234
Author(s):  
O.P. SINGH ◽  
ONKARI PRASAD
Keyword(s):  
Indian Ocean ◽  
Indian Ocean Dipole ◽  
Lead Time ◽  
Monsoon Rainfall ◽  
District Level ◽  
Annual Rainfall ◽  
Northeast Monsoon ◽  
Dipole Mode ◽  
Indian Ocean Dipole Mode ◽  
Northeast Monsoon Rainfall

The northeast monsoon season (October-December) contributes a substantial percentage of annual rainfall over Tamilnadu. The present paper describes a method for prediction of northeast monsoon rainfall (NEMR) over Tamilnadu on smaller spatial scale, i.e., district-level with sufficient lead time. Tamilnadu has been divided into ten homogeneous clusters of districts and the predictions are made for each cluster with lead times of two and one months using Indian Ocean dipole mode (IODM) index. A stronger western pole of IODM during August-September is associated with enhanced northeast monsoon activity over most of the districts of Tamilnadu. The predictions on the basis of regressions developed from NEMR and IODM index data have been validated for six years from 1997-2002. For many districts the mean errors between actual (realized) and predicted rainfall are within ±10%. Hence, using IODM index, it is possible to predict the NEMR activity over most of the districts of Tamilnadu with a lead time of two months, with only exception of NEMR over Kanyakumari which is not significantly correlated to IODM phenomenon.

scholarly journals Relationship between Indian Ocean dipole mode and summer monsoon

MAUSAM ◽  
2021 ◽  
Vol 59 (2) ◽  
pp. 167-172
Author(s):  
INDU BALA ◽  
O. P. SINGH
Keyword(s):  
Indian Ocean ◽  
Summer Monsoon ◽  
Indian Ocean Dipole ◽  
Summer Monsoon Rainfall ◽  
Monsoon Onset ◽  
Dipole Mode ◽  
Peninsular India ◽  
Indian Ocean Dipole Mode ◽  
The Indian Ocean ◽  
Withdrawal Phase

Utilizing the Indian Ocean Dipole Mode (IODM) and Indian Summer Monsoon Rainfall (ISMR) data for the period 1960-2002 the relationships between the IODM and monsoon onset over Kerala and rainfall distribution over the country have been studied. It has been found that stronger/weaker western pole during April-May is associated with delayed/early monsoon onset over Kerala. Stronger eastern pole during March-April seems to be associated with enhanced seasonal (June-September) rainfall over peninsular India. The IODM index of July-August can provide good indications of summer monsoon activity over peninsular India during the withdrawal phase of the  monsoon, i.e., during September.

Southern high latitude climate anomalies associated with the Indian Ocean dipole mode

2006 ◽  
Vol 24 (2) ◽  
pp. 125-128 ◽  
Author(s):  
Liu Na ◽  
Jia Zhen ◽  
Chen Hongxia ◽  
Hua Feng ◽  
Li Yunfang
Keyword(s):  
Indian Ocean ◽  
High Latitude ◽  
Indian Ocean Dipole ◽  
Dipole Mode ◽  
Indian Ocean Dipole Mode ◽  
Climate Anomalies ◽  
The Indian Ocean ◽  
Southern High Latitude

scholarly journals Improved Prediction of the Indian Ocean Dipole Mode by Use of Subsurface Ocean Observations

2017 ◽  
Vol 30 (19) ◽  
pp. 7953-7970 ◽  
Author(s):  
Takeshi Doi ◽  
Andrea Storto ◽  
Swadhin K. Behera ◽  
Antonio Navarra ◽  
Toshio Yamagata
Keyword(s):  
Indian Ocean ◽  
Indian Ocean Dipole ◽  
Three Dimensional ◽  
Coupled Model ◽  
Tropical Indian Ocean ◽  
Seasonal Prediction ◽  
Dipole Mode ◽  
Indian Ocean Dipole Mode ◽  
Ocean Data Assimilation ◽  
The Indian Ocean

Abstract The numerical seasonal prediction system using the Scale Interaction Experiment–Frontier version 1 (SINTEX-F) ocean–atmosphere coupled model has so far demonstrated a good performance for prediction of the Indian Ocean dipole mode (IOD) despite the fact that the system adopts a relatively simple initialization scheme based on nudging only the sea surface temperature (SST). However, it is to be expected that the system is not sufficient to capture in detail the subsurface oceanic precondition. Therefore, the authors have introduced a new three-dimensional variational ocean data assimilation (3DVAR) method that takes three-dimensional observed ocean temperature and salinity into account. Since the new system has successfully improved IOD predictions, the present study is showing that the ocean observational efforts in the tropical Indian Ocean are decisive for improvement of the IOD predictions and may have a large impact on important socioeconomic activities, particularly in the Indian Ocean rim countries.

A Diagnostic Study of the Indian Ocean Dipole Mode in El Niño and Non–El Niño Years

2007 ◽  
Vol 20 (13) ◽  
pp. 2961-2977 ◽  
Author(s):  
Hae-Kyung Lee Drbohlav ◽  
Silvio Gualdi ◽  
Antonio Navarra
Keyword(s):  
Indian Ocean ◽  
El Niño ◽  
Indian Ocean Dipole ◽  
El Nino ◽  
Western Indian Ocean ◽  
Wind Flow ◽  
Dipole Mode ◽  
Indian Ocean Dipole Mode ◽  
Anticyclonic Circulation ◽  
The Indian Ocean

Abstract The Indian Ocean dipole mode (IODM) is examined by comparing the characteristics of oceanic and atmospheric circulations, heat budgets, and possible mechanisms of IODM between El Niño and non–El Niño years. Forty-year ECMWF Re-Analysis (ERA-40) data, Reynolds SST data, and ocean assimilation data from the Modular Ocean Model are used to form composites of the IODM that occur during El Niño (1972, 1982, and 1997) and non–El Niño (1961, 1967, and 1994) years. In El Niño years, two off-equatorial, anticyclonic circulations develop, associated with the increased pressure over the eastern Indian Ocean. The anticyclonic circulation over the Northern Hemisphere enhances the easterly component of the winds in the northwestern Indian Ocean. This enhanced easterly component increases the mixed layer temperature by inducing an anomalous westward ocean current that advects the warm mean mixed layer from the central to the western Indian Ocean. Meanwhile, the anticyclonic circulation over the southeastern Indian Ocean strengthens southeasterlies, thereby causing oceanic meridional and vertical advection of the cold mean temperature. Consequently, the IODM in El Niño years is characterized by the warming in the northwestern and the cooling in the southeastern Indian Ocean. In non–El Niño years, a monsoonlike wind flow increases the westerly and southeasterly components of the wind over the northwestern and southeastern Indian Ocean, respectively. Oceanic currents induced by these winds result in anomalous cold advection in both of these regions. In addition, the monsoonlike wind flow over the southeastern Indian Ocean enhances the anomalous latent and sensible heat fluxes in non–El Niño years. Hence, the cooling of the eastern tropical Indian Ocean, rather than the warming of the western Indian Ocean, becomes the major feature of the IODM during non–El Niño years.

The influence of the Indian Ocean dipole mode on precipitation over the Seychelles

2006 ◽  
Vol 26 (1) ◽  
pp. 45-54 ◽  
Author(s):  
Aurelie P. Harou ◽  
Robert F. Lajoie ◽  
Dominic R. Kniveton ◽  
Michael R. Frogley
Keyword(s):  
Indian Ocean ◽  
Indian Ocean Dipole ◽  
Dipole Mode ◽  
Indian Ocean Dipole Mode ◽  
The Indian Ocean
Sign in / Sign up

Export Citation Format

Share Document