Changes in precipitation pattern and risk of drought over India in the context of global warming

Abstract

Precipitation pattern has changed over many regions in recent decades. There are evidences of increased heavy precipitation and decreased light precipitation in widespread parts of the globe due to global warming. Many studies over Indian region focus on heavy precipitation and risk of floods. But few works discuss the changes in light precipitation and risk of droughts. In this study, changes in total dry days, prolonged dry spells, light precipitation, and risk of drought as indicated by Modified Palmer Index (MPI) over India during six decades are examined quantitatively in the context of global warming. It is found that there are increases of 49% ± 21% and 33% ± 17% in prolonged dry spells and total dry days, respectively, over India for each degree Kelvin (K) increase in global mean temperature. There is an increase of 51% ± 24% K À1 in drought index MPI (<= À 2.0). There is also a reduction of 31 ± 14% K À1 in light precipitation days over India. These changes are more severe over northeastern and western part of India. Increases in prolonged dry spells, total dry days, and decreases in light precipitation relate well with the increases in drought index MPI (<= À 2.0). These results suggest that there is an increased risk of drought due to increased prolonged dry spells, total dry days, and decreased light precipitation days over India as a result of global warming.

Variability of integrated precipitable water over India in a warming climate

“…Thus, the IPW shows a decadal increase of about 1.69% over India (4.98 × 0.34). An increase in the IPW is consistent with an increase in heavy precipitation over India in a warming environment (Mishra and Liu, ; Mishra, ). Furthermore, temperature data from the MERRA‐2 are also used to examine the impact of warming.…”

A study of heavy snowfall in Kashmir, India in January 2017

“…Such episodes of heavy snowfall have been linked to an increase in global temperature during recent decades. This temperature increase leads to changes in precipitation patterns (Trenberth et al ., ), including an increase in heavy precipitation and a decrease in low or moderate precipitation (O'Gorman, ; Villarini et al ., ; Mishra and Liu, ). Increasing temperatures lead to an increase in the water holding capacity of the atmosphere, and an increase in the amount of water vapour in the atmosphere may, in turn, cause an increase in precipitation intensity as a result of the release of extra latent heat.…”

Quantifying the impact of global warming on precipitation patterns in India

“…Past researchers have reported changes in precipitation patterns as a result of global warming (Trenberth et al ., ; Mishra and Liu, ; Lehmann et al ., ; Donat et al ., ). These changes include an increase in heavy precipitation and a decrease in light and moderate rain (Goswami et al ., ; Lau and Wu, ; Rajeevan et al ., ; Dash et al ., ; O'Gorman, ; Villarini et al ., ; Mishra and Liu, ). It is well known that warmer air can hold more water vapour.…”