The internal climate variability of HadCM3, a version of the Hadley Centre coupled model without flux adjustments
The internal climate variability of HadCM3, a version of the Hadley Centre coupled model without flux adjustments
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DOI：
10.1007/s003820000094
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发表时间：
2001-01-01
期刊：
影响因子：
4.6
通讯作者：
Cooper, C
中科院分区：
文献类型：
--
作者：
Collins, M;Tett, SFB;Cooper, C
我们研究了Hadley中心第三版耦合模式（HadCM3） 1000年积分的内部气候变率。该模式不需要通量调整，在耦合之前不需要自旋上升过程，在全球平均范围内具有稳定的气候。主要目的是：(1)根据观测到的气候变率验证内部气候变率，(2)检查模型的任何周期变率模式，(3)使用模型对内部气候变率的估计来评估观测到的气候变量趋势发生的概率，(4)将HadCM3与Hadley中心模型HadCM2的先前版本进行比较。HadCM3全球平均地表温度在年-年代际尺度上的变率幅度和频率特征与观测值吻合较好。在过去20年及更长的时间里观测到的温度上升趋势与模式的内部变率不一致。模拟的地表温度变率空间格局在质量上与观测结果相似，但存在对陆地温度变率的过高估计和海洋温度变率的区域误差。该模式模拟了厄尔尼诺-南方涛动，其不规则周期为3-4年，与HadCM2的观测结果相比，其遥相关模式更接近观测结果。热带太平洋、北太平洋和北大西洋的模式海洋的年代际变率与现实世界大致相似，模拟的模式都没有任何周期性行为。HadCM3模拟了北半球冬季的北极涛动/北大西洋涛动（NAO），其空间格局与大西洋地区的观测结果一致，但与北太平洋的遥相关过多。最近观测到的NAO指数上升趋势与模式内部变率不一致。模拟的纬向平均气温的变率与观测到的纬向平均气温变率有一些显著的差异，尽管这种比较受到稀疏观测网络及其可能受到气候变化信号污染的影响。
We examine the internal climate variability of a 1000 year long integration of the third version of the Hadley Centre coupled model (HadCM3). The model requires no flux adjustment, needs no spin up procedure prior to coupling and has a stable climate in the global mean. The principal aims are (I) to validate the internal climate variability against observed climate variability, (2) to examine the model for any periodic modes of variability, (3) to use the model estimate of internal climate variability to asses the probability of occurrence of observed trends in climate variables, and (4) to compare HadCM3 with the previous version of the Hadley Centre model, HadCM2. The magnitude and frequency characteristics of the variability of the global mean surface temperature of HadCM3 on annual to decadal time scales is in good agreement with the observations. Observed upward trends in temperature over the last 20 years and longer are inconsistent with the internal variability of the model. The simulated spatial pattern of surface temperature variability is qualitatively similar to that observed, although there is an overestimation of the land temperature variability and regional errors in ocean temperature variability. The model simulates an El Nino Southern Oscillation with an irregular 3-4 year cycle, and with a teleconnection pattern which is much more like the observations than was found in HadCM2. The interdecadal variability of the model ocean in the tropical Pacific, North Pacific and North Atlantic is broadly similar to that in the real world with none of the simulated patterns having any periodic behaviour. HadCM3 simulates an Arctic Oscillation/North Atlantic Oscillation (NAO) in Northern Hemisphere winter which has a spatial pattern consistent with the observations in the Atlantic region, but has too much teleconnection with the North Pacific. The recent observed upward trend in the NAO index is inconsistent with the model internal variability. The variability of the simulated zonal mean atmospheric temperature shows some marked differences to the observed zonal mean temperature variability, although the comparison is confounded by the sparse observational network and its possible contamination by a climate change signal.