论文部分内容阅读
1997/98年强ElNio背景下西太平洋暖池区云辐射强迫的变化,表现出诸多不同于以往的特征,已经成为检验气候模式性能的一个重要标准。本文基于卫星资料,分析了大气环流模式GAMIL1.0和2.0版对上述现象的模拟能力。结果表明,GAMIL1.0模式对热带地区云辐射特征分布,尤其对西太平洋暖池区的长(短)波云辐射强迫及其异常的模拟结果均和观测接近,但其模拟的长(短)波云辐射以及净云辐射冷却作用的强度均偏强,且模拟的1998年异常亦不如观测明显。GAMIL2.0对热带云辐射强迫空间分布的模拟较GAMIL1.0存在一定改进,但其未能模拟出1998年暖池地区云辐射强迫异常。对比观测发现,暖池区云辐射强迫的模拟偏差主要源自模式对该处云量、云水路径及云垂直结构的模拟偏差。在GAMIL1.0中,它们共同造成模拟的短波云辐射明显偏强,而其相互补偿使长波云辐射模拟略好于前者,导致模拟净云辐射冷却作用过强。在GAMIL2.0中,高估的云水路径致使短波云辐射过强,而其模拟云量、平均云顶高度偏低则导致长波云辐射强迫偏弱。模式的晴空短(长)波辐射通量过高(低),亦对模拟短波云辐射强迫以及净云辐射冷却作用偏强有影响。
Changes in radiative forcing in the western Pacific warm pool in the 1997/98 strong El Nio environment show many different characteristics from the past and have become an important criterion for testing the performance of climate models. Based on satellite data, this paper analyzes the ability of atmospheric circulation model GAMIL1.0 and 2.0 to simulate the above phenomena. The results show that the GAMIL1.0 model is close to the observed results for the distribution of cloud radiation in tropical regions, especially for the long (short) wave radiative forcing and its anomalies in the western Pacific warm pool area. However, the simulated long (short) The intensities of wave cloud radiation and net cloud radiation cooling are both stronger, and the simulated 1998 anomalies are not as obvious as the observations. GAMIL2.0 simulated the spatial distribution of the radiative forcing of tropical clouds to a certain degree, but failed to simulate the 1998 1998 forced coalescence of cloud radiation. Comparing the observed results, it is found that the simulated deviations of cloud radiation forcing in the pool area are mainly due to the simulated deviations of cloud volume, cloud water path and cloud vertical structure. In GAMIL1.0, they together make the simulated short-wave cloud radiation significantly stronger, and their mutual compensation make the long-wave cloud radiation simulation slightly better than the former, resulting in the simulation of net cloud radiation cooling too strong. In GAMIL2.0, the overestimation of the cloud water path caused the shortwave radiation to be too strong, while the simulated cloudiness and the low average cloud top resulted in the weakening of the longwave radiation. The pattern of clear sky short (long) wave radiation flux is too high (low), but also on the analog shortwave cloud radiation coercion and net cloud radiation cooling effect has a strong influence.