Weakening Trends in the South Asian Monsoon

Photo: Prasad

Abstract: The south Asian monsoon rains contribute to 75-80 per cent of the region’s annual precipitation. Thus the response of the monsoon hydrological cycle to global climate change becomes an issue of major concern.

The author is Programme Manager, Centre for Climate Change Research, Indian Institute of Tropical Meteorology. krish@tropmet.res.in


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A weather condition characterised by low temperatures, winds with 35 mph or greater, and sufficient falling and/or blowing snow in the air to reduce visibility to 1/4 mile or less for a duration of at least 3 hours. A severe blizzard is characterised by temperatures below -12OC, winds exceeding 45 mph, and visibility reduced by snow to near zero.

An extreme precipitation event a cloudburst may occur with hail and thunder, which normally lasts no longer than a several minutes but is capable of creating floods. Colloquially, the term cloudburst may be used to describe any sudden heavy, brief, and unprecedented rainfall.

A weather phenomenon distinguished by a sudden cooling of the air, with a rapid fall in temperature within a 24 hour period, requiring substantially increased protection. The precise criterion for a cold wave is determined by the rate at which the temperature falls, and the minimum to which it falls.

A warming phenomena of the surface waters of the tropical Pacific that occurs every 3 to 5 years, temporarily affecting weather worldwide.

A tornado-like rotating column of fire and smoke created by intense heat from a forest fire or volcanic eruption.

Also known as the hypocenter, the term refers to the site of an earthquake. An earthquake's hypocenter is the position where the strain energy stored in the rock is first released, marking the point where the fault begins to rupture. This occurs at the focal depth below the epicenter.

A medical condition that occurs due excessive exposure to extremely cold weather. It usually affects the extremities of the human body. Frostbite is dangerous as there is no sensation of pain, and the victims may not even know that they have been frostbitten.

Sudanese name for a duststorm or sandstorm characterised by strong winds that carry small particles of dirt or sand into the air - particularly severe in areas of drought.

A form of very short-range weather forecasting, covering only a very specific geographic area. A now cast is loosely defined as a forecast for the coming 12-hour period, based on detailed observational data.