Intercomparison of summer rainfall diurnal features between station rain gauge data and TRMM 3B42 product over central eastern China

Abstract This study examines the differences in diurnal variations of summer (June–August) rainfall recorded in the station rain gauge data (Gdata) and Tropical Rainfall Measuring Mission 3B42 product (Tdata) over central eastern China during 1998–2006. For the diurnal variations, rainfall amount and frequency in Tdata get the maximum in the afternoon, against the double diurnal peaks in the morning and afternoon of Gdata. For the intensity, the principal morning peak in Tdata contrasts with the dominated afternoon peak in Gdata. It is found that the massive morning light rainfall, which is missed by Tdata, greatly contributes to the weakened morning diurnal peaks of amount and frequency and the stronger morning intensity in Tdata. The overestimated afternoon rainfall in Tdata, including the light rainfall detected only by Tdata and the enhanced rainfall in Tdata when both datasets measure the rainfall, strengthens the afternoon peak of rainfall amount and frequency. In addition, the light rainfall in the morning missed by Tdata is more prevalent in plains than in mountains, whereas the overestimation of afternoon rainfall is more significant in mountain regions. For the diurnal rainfall amount, the afternoon peak in Tdata differs from the morning peak in Gdata in plains and the afternoon peak of Tdata is enhanced in mountain regions. Copyright © 2011 Royal Meteorological Society