Search Results

You are looking at 1 - 5 of 5 items for

  • Author or Editor: K. Raghavan x
  • Refine by Access: All Content x
Clear All Modify Search
K. RAGHAVAN

Abstract

A cloud-free zone adjoining the Indian Peninsula, observed from Gemini XI on Sept. 14, 1966, is attributable to upwelling. A possible connection between a weak southwest monsoon, coastal upwelling, and below-normal rainfall is suggested.

Full access
K. Raghavan

Abstract

Full access
K. RAGHAVAN

Abstract

Interruption of monsoon rainfall by prolonged spells of sparse rainfall (break-monsoon) during the mid-monsoon months of July and August over the plains of northern India (20°–29°N, 75°–85°E) has been investigated. When a tropical low-pressure system moves from the plains in a northerly direction toward the submontane region of the Himalaya, the monsoon trough of low pressure also moves from the plains to that region. This deprives the plains of northern India of significant ascending motion and normal rainfall and brings about the break-monsoon. During the break-monsoon period, descending motion takes place from the stratosphere to the lower troposphere over the plains, while ascending motion occurs in the regions to the north and south of the plains. As the descending motion persists over the plains, the break-monsoon intensifies and the weather turns mainly dry. A vertical circulation model for the break-monsoon period is proposed. The break-monsoon ceases and normal monsoon conditions are re-established when the monsoon trough returns to the plains and intensifies. This occurs in association with tropical low-pressure systems developing at or near the Bay of Bengal and moving toward the plains. The genesis and persistence of the break-monsoon, therefore, depends mainly on the interaction between the monsoon trough and tropical low-pressure systems of the Indian region.

Full access
D. R. Sikka
and
K. Raghavan

Abstract

No abstract available.

Full access
K. Raghavan
,
P. V. Puranik
,
V. R. Mujumdar
,
P. M. M. Ismail
, and
D. K. Paul

Abstract

Examination of the July 1964 sea surface temperatures in the west Arabian Sea shows that during the weak monsoon over India the sea surface experienced a significant drop in temperature over a larger area compared to a period of strong monsoon. Associated with weak and strong monsoon over India are large-scale pressure changes which occur almost over the entire monsoon region and these changes are not considered to be directly related to the sea surface temperature. The pressure change over India appears to have a controlling influence on the strength of the cross-equatorial flow in the west Arabian Sea.

Full access