## 5 Conclusions  
This study provides an early and timely quantitative study of the error characteristics for GPM and its predecessor-TRMM rainfall products with high temporal resolution (i.e., three-hourly) across the TP. The intercomparison is based on multiple evaluations with the best available rain gauge network at the grid cell and basin scales. Furthermore, we have investigated the impact of elevation and latitude on rainfall analysis. In addition to the IMERG and 3B42V7 satellite rainfall error analysis, the snowfall error analysis from IMERG is carried out at a site of the TP. Primary conclusions are summarized as follows:  
1. Overall, IMERG and 3B42V7 show similar rainfall patterns across the TP, with a decreasing trend from the southeast to the northwest. However, IMERG performs better, with slightly higher correlation and lower bias than 3B42V7 at the three-hourly scale, although both datasets show similar spatial patterns for all assessment indicators.
2. As elevations increase, there is no obvious difference in CC between IMERG and 3B42V7. However, IMERG shows slightly lower POD for elevations above 4200 m and significantly smaller FAR for elevations below 3000 m. In addition, higher consistency is detected from the IMERG products for light rainfall than 3B42V7 estimates.
3. The latitudinal rainfall gradients of the Indian monsoon dynamics are successfully detected by the two satellite estimates. In particular, the relatively light rain from the early and end Indian monsoon moisture surge events is often not observed by the sparse gauges over the TP.
4. Over high and complex TP regions, this study provides the very first understanding of GPM at the hourly scale and confirms the desired results that the GPM-era Day-1 Level-3 products perform at least equally well, often times better for light and solid precipitation at high elevations, than the TRMM V7 mature products.  
The GPM Core Observatory sensors are expected to have the ability to detect cold-season solid precipitation, but only one snowfall site in the northeastern TP is available for evaluating the IMERG snowfall product. Conducting snowfall observation and evaluation across the TP are our ongoing work.  
**Supplementary Materials:** The following are available online at www.mdpi.com/2072-4292/8/7/569/s1, Figure S1: Spatial patterns of snowfall occurrence probability (unit: %) derived from IMERG products during the cold season (i.e., October to the next March) of 2014 over the TP. Figure S2: Spatial patterns of snowfall amounts (unit: mm) derived from IMERG products during the cold season (i.e., October to the next March) of 2014 over the TP. Table S1: The geographical location of 258 automatic gauges over the Tibetan Plateau and the 19 stations used for GPCC gridded gauge-analysis products.  
**Acknowledgments:** The authors' gratitude is extended to the China Meteorological Administration (CMA) for providing ground-based rainfall data for this study. The efforts of the GPM research community are also highly appreciated for making the satellite rainfall data available for this work. This work is financially supported by the National Natural Science Foundation of China (Grant Nos. 91437214 and 91547210). [PERSON] is partly supported through the China Postdoctoral Science Foundation (Grant No. 2015 MS81107).  
**Author Contributions:** [PERSON] analyzed the data and prepared the draft of the manuscript. [PERSON] prepared the satellite precipitation data and revised the manuscript. [PERSON] gave comments and significantly revised the manuscript. Both [PERSON] and [PERSON] handled the gauge data. [PERSON] conceived of this study, gave comments and revised the manuscript.  
**Conflicts of Interest:** The authors declare no conflict of interest.