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The Uneven Nature of Daily Precipitation and Its Change
Author(s) -
Pendergrass Angeline G.,
Knutti Reto
Publication year - 2018
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2018gl080298
Subject(s) - precipitation , drizzle , environmental science , climate change , climatology , greenhouse gas , atmospheric sciences , meteorology , geography , geology , oceanography
A few days with heavy rain contribute disproportionately to total precipitation, while many days with light drizzle contribute much less. What is not appreciated is just how asymmetric this distribution is in time, and the even more asymmetric nature of trends due to climate change. We diagnose the temporal asymmetry in models and observations. Half of annual precipitation falls in the wettest 12 days each year in the median across observing stations worldwide. Climate models project changes in precipitation that are more uneven than present‐day precipitation. In a scenario with high greenhouse‐gas emissions, one fifth of the projected increase in rain falls in the wettest 2 days of the year and 70% in the wettest 2 weeks. Adjusting modeled unevenness to match present‐day unevenness at stations, half of precipitation increase occurs in the wettest 6 days each year.