On the Importance of Precipitation-Induced Surface Sensible Heat Flux for Diurnal Cycle of Precipitation in the Maritime Continent

Abstract

The Maritime Continent (MC) exhibits a pronounced diurnal cycle in precipitation, with many high-resolution models overestimating the diurnal peak and predicting earlier precipitation over the islands than observed. We hypothesize that part of this model bias comes from ignoring precipitation-induced surface sensible heat flux (Q_P). To test this conjecture, we performed simulations with and without Q_P for April 2009 and June 2006. The inclusion of Q_P reduced the bias in diurnal peak precipitation amplitude by 83% in April 2009 and 23% in June 2006. Similarly, the bias in precipitation peak timing decreased by 26% and 15%, respectively. This bias reduction was even more prominent during periods of heavier rainfall. This improvement in both the amplitude and phase of diurnal precipitation also led to a reduction in bias for total precipitation by ∼10%. These findings suggest that Q_P cannot be neglected over the MC, particularly during heavy precipitation.