Rainfall and temperature scenarios for Bangladesh for the middle of 21st century using RegCM
Rainfall and temperature scenarios for Bangladesh for the middle of 21st century using RegCM
复制标题
使用 RegCM 绘制孟加拉国 21 世纪中叶的降雨量和温度情景
DOI：
10.1007/s12040-012-0159-9
复制
发表时间：
2012
影响因子：
1.9
通讯作者：
F. Georgi
中科院分区：
文献类型：
--
作者：
Md. Mizanur Rahman;Md. Nazrul Islam;Ahsan Ahmed;F. Georgi
区域气候模式第三版（RegCM 3）采用ECHAM 4排放情景A2，在0.54°×0.54°水平网格分辨率下，采用Grell方案和Arakawa-Schubert（GAS）和Fritch-Chappell（GFC）两种参数化方案。对1961-1990年期间孟加拉国的地面观测数据进行了模拟降雨量和平均地面气温的校准和验证。气候研究单位（CRU）的数据也用于了解模式的性能。通过验证过程获得的RegCM 3更好的性能，使其有信心在孟加拉国的降雨和温度预测在世纪中期。孟加拉国的降雨量和平均地面气温预测是实验获得的2050年和2060年。这项工作揭示了模拟降雨和温度是不直接有用的面向应用的任务。然而，经过校准和验证，合理的性能可以得到估计季节和年降雨量，平均地表气温在孟加拉国。预计到2050年，孟加拉国季风季节（JJAS）的降雨量变化约为+35%，季风前（MAM）为-67%，季风后（ON）为-12%，冬季（DJF）为107%。平均而言，2060年所有季节的降雨量可能会减少50%以上。同样地，预测2050年和2060年不同月份的平均地面气温变化分别为0.5°-2.1 ° C和0.9°-3.5 ° C。
Regional Climate Model of version 3 (RegCM3) was driven with Emissions Scenarios A2 of ECHAM4 at 0.54°×0.54° horizontal grid resolution in two parameterizations: Grell scheme with Arakawa–Schubert (GAS) and Fritch–Chappell (GFC) assumptions. The simulated rainfall and mean surface air temperature were calibrated and validated against ground-based observed data in Bangladesh during the period 1961–1990. The Climate Research Unit (CRU) data is also used for understanding the model performance. Better performance of RegCM3 obtained through validation process, made it confident in utilizing it in rainfall and temperature projection for Bangladesh in the middle of 21st century. Rainfall and mean surface air temperature projection for Bangladesh is experimentally obtained for 2050 and 2060. This work discloses that simulated rainfall and temperature are not directly useful in application-oriented tasks. However, after calibration and validation, reasonable performance can be obtained in estimating seasonal and annual rainfall, and mean surface air temperature in Bangladesh. The projected change of rainfall for Bangladesh is about +35% for monsoon season (JJAS), −67% for pre-monsoon (MAM), −12% for post-monsoon (ON) and 107% for winter (DJF) for 2050. On an average, rainfall may be less by more than 50% for all seasons for the year 2060. Similarly, change of mean surface air temperature in different months is projected about 0.5°–2.1°C and 0.9°–3.5°C for the year 2050 and 2060, respectively.