長期氣候變遷對長江流域暖季東移雨帶的影響與評估：以2009年5月為例

In this study, we use WRF model driven by three different climate conditions (the original, the past and the future) to study the effects of long-term climate change on the eastward propagating rainfall events over the Yangtze River Valley. Using May 2009 as an example, the results show that (1) under the original climate condition (i.e. Control Run), the characteristics of eastward propagating rainfall events simulated by the model are similar to the observations; (2) with the effects of past climate change (i.e. Past Run), the simulated number of propagating event is fewer; the propagating distance is shorter; and the rainfall intensity is weaker than the Control Run; (3) with the effects of future climate change (i.e. Future Run), only the rainfall intensity is noticeably stronger than the Control Run. Diagnoses on the circulation change suggest that (1) the change in upper-level westerly is responsible for the change in occurrence frequency and propagating distance of rainfall events, and (2) the change in moisture flux convergence is responsible for the change in rainfall intensity over the Yangtze River Valley.