Evaluation and Projection of Extreme Precipitation over Northern China in CMIP5 Models

Abstract

<p>This study evaluates 32 climate models from CMIP5 compared with a daily gridded<br>observation dataset of extreme precipitation indices including total extreme precipitation (R95p),<br>maximum consecutive five days of precipitation (RX5day) and wet days larger than 10 mm of<br>precipitation (R10mm) over Northern China during the historical period (1986–2005). Results show<br>the majority models have good performance on spatial distribution but overestimate the amplitude of<br>precipitation over Northern China. Most models can also capture interannual variation of R95p and<br>RX5d, but with poor simulations on R10mm. Considering both spatial and temporal factors, the best<br>multi-model ensemble (Group 1) has been selected and improved by 42%, 34%, and 37% for R95p,<br>RX5d, and R10mm, respectively. Projection of extreme precipitation indicates that the fastest-rising<br>region is in Northwest China due to the enhanced rainfall intensity. However, the uncertainty<br>analysis shows the increase of extreme rainfall over Northwest China has a low confidence level.<br>The projection of increasing extreme rainfall over Northeast China from Group 1 due to the longer<br>extreme rainfall days is more credible. The weak subtropical high and southwest winds from Arabian<br>Sea lead to the low wet biases from Group 1 and the cyclonic anomalies over Northeast China, which<br>result in more extreme precipitation.</p>