This study evaluated three satellite precipitation products, namely, TRMM, CMORPH, and PERSIANN, over the Three Gorges Reservoir area in China at multiple timescales. The assessment covered the following aspects: the rainfall amount, extreme precipitation, and the rainy-day detection ability. Results indicated that the CMORPH and TRMM estimates of rainfall amount were reasonably good, but the PERSIANN showed a larger bias than the other two satellite products. The data precision of CMORPH was slightly better than TRMM. All three satellite products could reproduce the diurnal cycle of rainfall, i.e., more precipitation in the morning than in the evening. The CMORPH estimates were closest to the gauge observation at 3-hourly and 12-hourly timescales. The data accuracy of CMORPH data was better during the night than in the daytime. At daily timescale, the quality of TRMM data was slightly inferior to the CMORPH, whereas the PERSIANN still differed much from the ground observation. At monthly, seasonally, and yearly timescales, the performance of TRMM was comparable to CMORPH, and both of them were obviously superior to PERSIANN. The rainy-day detection ability of CMORPH and TRMM was much better than PERSIANN. The PERSIANN data tended to overestimate the light rainy days but underestimate the heavy and torrential rainy days. The CMORPH data overestimated mainly the moderate rainy days. The TRMM data overestimated the occurrence frequency of heavy rain during the winter half year (from October to the next March). Both the CMORPH and the TRMM provided good estimates of the regional average rainy days. The data accuracy of CMORPH was slightly better than TRMM, and both were far better than the PERSIANN with respect to the rainfall amount and rainy-day detection. Nevertheless, all satellite estimates showed large biases of extreme precipitation. The CMORPH estimate of the maximum 5-day precipitation was the best of all. Both the CMORPH and TRMM data overestimated the 95th percentile of precipitation, but the PERSIANN data severely underestimated it. The PERSIANN estimates of extreme precipitation amount were the best of all during the daytime, nighttime, and the whole day. The above evaluation results could facilitate the application of satellite rainfall products and provide a reference to precipitation-related studies.

In this study, we investigated the interdecadal variability (IDV) of winter precipitation in the Greater Mekong Subregion (GMS) between 1892 and 2016. The results showed that the precipitation IDV was characterized mainly by opposite variations between the southern and northern parts of GMS. This IDV pattern was closely linked to the Atlantic multidecadal oscillation (AMO). Rossby waves excited by the AMO modulated the atmospheric circulation across Eurasia, inducing an EU‐like teleconnection with alternating cyclonic and anticyclonic anomalies across Eurasia. The GMS was directly affected by the anticyclonic anomaly over East Asia. This anticyclonic anomaly had dual effects on the GMS precipitation. Firstly, it caused a descending anomaly over the northern GMS and generated easterly anomalies that impeded the moisture transport from the northern BOB. Secondly, it strengthened the East Asian winter monsoon (EAWM) that weakened the western North Pacific anticyclone (WNPAC) to facilitate moisture transport from South China Sea to the southern GMS. Consequently, the precipitation varied inversely between the southern and northern parts of GMS. Numerical experiments confirmed the causal link between the AMO and IDV of winter precipitation in the GMS.

This research describes a link between winter-springtime snow cover anomalies in central Europe and precipitation over the low-latitude highlands of China (LLHC). Excessive snow cover over Europe and East Asia alters the meridional temperature gradient, which induces zonal wind anomalies at the 500 hPa level that impact the strength and position of subtropical streams.