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Understanding the Dynamic Contribution to Future Changes in Tropical Precipitation From Low‐Level Convergence Lines
Author(s) -
Weller Evan,
Jakob Christian,
Reeder Michael J.
Publication year - 2019
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 - 10.1029/2018gl080813
Subject(s) - precipitation , convergence (economics) , climatology , environmental science , tropics , convergence zone , atmospheric sciences , meteorology , geology , geography , fishery , economics , biology , economic growth
Future precipitation changes include contributions from both thermodynamic and dynamic processes. Given that precipitation in the tropics is commonly associated with convergence lines, we construct a simple linear regression model relating the convergence line frequency and strength to precipitation at subdaily time scales, and use it to show that changes in the convergence lines are related to the dynamic change in the precipitation. Given GCM‐predicted convergence line changes, we predict precipitation changes using the regression model. The so‐predicted precipitation change is equivalent to the dynamic component of the precipitation change identified in earlier studies that used very different methods. The difference between the precipitation change in GCMs and that predicted from changes in convergence lines accounts for thermodynamic and other potentially important dynamic contributions. More accurate predictions of future precipitation therefore require the accurate simulations of the relatively short‐lived weather features responsible for convergence lines in the tropics in GCMs.