Detection and attribution of anthropogenic forcing to diurnal temperature range changes from 1950 to 1999: comparing multi-model simulations with observations
Detection and attribution of anthropogenic forcing to diurnal temperature range changes from 1950 to 1999: comparing multi-model simulations with observations
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DOI：
10.1007/s00382-009-0644-2
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发表时间：
2009-12
期刊：
影响因子：
4.6
通讯作者：
Liming Zhou;R. Dickinson;A. Dai;P. Dirmeyer
中科院分区：
文献类型：
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作者：
Liming Zhou;R. Dickinson;A. Dai;P. Dirmeyer
观测表明，自 20 世纪 50 年代以来，全球大部分陆地区域的地表昼夜温差 (DTR) 有所下降，原因是最高气温 (Tmax) 的升温幅度小于最低气温 (Tmin) 的幅度。本文分析了 20 世纪下半叶 12 个全球大气-海洋耦合大气环流模型的观测和 48 次模拟中陆地 Tmax、Tmin 和 DTR 的趋势和变化。它使用模拟的地表向下太阳辐射和长波辐射的变化来解释模拟的温度变化。当包括人为和自然强迫时，模型通常会重现观察到的 Tmax 和 Tmin 变暖以及 DTR 减少的主要特征。正如预期的那样，温室气体增强的地表向下长波辐射 (DLW) 解释了 Tmax 和 Tmin 的大部分变暖，而由于气溶胶和水蒸气的增加而导致地表向下短波辐射 (DSW) 的减少是模型中 DTR 降低的主要原因。当仅使用自然强迫时，不会模拟任何观察到的趋势。模拟的 DTR 下降远小于观察到的（主要是由于模拟的 Tmintrend 小），但仍然超出了模型估计的自然内部变异范围。观察到的 DTR 大幅下降表明，模型无法实际模拟的人为强迫的额外区域效应可能与云量、降水和土壤湿度的变化有关。模拟的 DTR 趋势幅度较小可能是由于云量没有增加趋势以及模型中气溶胶和重要的表面和边界层过程特征的缺陷。
Observations show that the surface diurnal temperature range (DTR) has decreased since 1950s over most global land areas due to a smaller warming in maximum temperatures (Tmax) than in minimum temperatures (Tmin). This paper analyzes the trends and variability inTmax,Tmin, and DTR over land in observations and 48 simulations from 12 global coupled atmosphere-ocean general circulation models for the later half of the 20th century. It uses the modeled changes in surface downward solar and longwave radiation to interpret the modeled temperature changes. When anthropogenic and natural forcings are included, the models generally reproduce observed major features of the warming ofTmaxandTminand the reduction of DTR. As expected the greenhouse gases enhanced surface downward longwave radiation (DLW) explains most of the warming ofTmaxandTminwhile decreased surface downward shortwave radiation (DSW) due to increasing aerosols and water vapor contributes most to the decreases in DTR in the models. When only natural forcings are used, none of the observed trends are simulated. The simulated DTR decreases are much smaller than the observed (mainly due to the small simulatedTmintrend) but still outside the range of natural internal variability estimated from the models. The much larger observed decrease in DTR suggests the possibility of additional regional effects of anthropogenic forcing that the models can not realistically simulate, likely connected to changes in cloud cover, precipitation, and soil moisture. The small magnitude of the simulated DTR trends may be attributed to the lack of an increasing trend in cloud cover and deficiencies in charactering aerosols and important surface and boundary-layer processes in the models.