一个海-冰-气耦合模式中格陵兰海海冰年际变异及其成因的个例分

利用一个全球海-冰-气耦合模式模拟结果, 选取冬季年际变率最大的海冰区--格陵兰海海冰区中的一个4年海冰剧烈变化过程展开分析, 试图探讨此个例过程中海冰剧烈变化的原因.结果表明, 在此个例中, 该区域海冰年际变异主要是由大气环流异常驱动的, 海表面温度和海冰密集度变化主要是对大气环流变化的响应.海表面温度变化决定着海冰范围及海冰密集度的变化, 但海冰变化时通过相变潜热的释放或吸收反过来对海表面温度变化有一定影响.     

一个统计低云方案及其在大气环流模式中应用初探

文中利用湍流耗散特征时间尺度和湍流垂直扩散系数对湍流二阶距进行参数化 ,将一个统计云方案与一阶湍流闭合方案进行耦合。基于数值试验 ,在不同的相对湿度、温度垂直梯度、以及湍流耗散特征时间尺度条件下 ,对该方案云量模拟能力的分析 ,发现该统计云方案对其采用的参数及湍流耗散特征时间尺度敏感。基于该数值模拟分析 ,修改了该统计云方案 ,并结合其他边界层积云参数化方案 ,给出了一个基于统计的低云参数化方案。将其初步应用于NCARCCM 3后发现 :该方案可以显著增强CCM 3对副热带低云的模拟能力 ,可以合理地模拟出大洋东部大陆西岸冷海域低云量大值中心 ,显示出该方案对于改进大气环流模式低云参数化具有潜在的应用前景。     

The Role of the Kuroshio in the Winter North Pacific Ocean-Atmosphere Interaction： Comparison of a Coupled Model and Observations

A comparative study between the output of the Flexible Global Climate Model Version 1.0 (FGCM- 1.0) and the observations is performed. At 500 hPa, the geopotential height of FGCM is similar to the observations, but in the North Pacific the model gives lower values, and the differences are most significant over the northern boundary of the Pacific. In a net heat flux comparison, the spatial patterns of the two are similar in winter, but more heat loss appears to the east of Japan in FGCM than in COADS. On the interannual timescale, strong (weak) Kuroshio transports to the east of Taiwan lead the increasing (decreasing) net heat flux, which is centered over the Kuroshio Extension region, by 1–2 months, with low (high) pressure anomaly responses appearing at 500 hPa over the North Pacific (north of 25N) in winter. The northward heat transport of the Kuroshio is one of the important heat sources to support the warming of the atmosphere by the ocean and the formation of the low pressure anomaly at 500 hPa over the North Pacific in winter.     

Simulating Crop Net Primary Production in China from 2000 to 2050 by Linking the Crop-C model with a FGOALS's Model Climate Change Scenario

Net primary production(NPP)of crop represents the capacity of sequestrating atmospheric CO_2 in agro-ecosystem,and it plays an important role in terrestrial carbon cycling.By linking the Crop-C model with climate change scenario projected by a coupled GCM FGOALS via geographical information system (GIS)techniques,crop NPP in China was simulated from 2000 to 2050.The national averaged surface air temperature from FGOALS is projected to increase by 1.0℃over this period and the corresponding atmospheric CO_2 concentration is 535 ppm by 2050 under the IPCC AIB scenario.With a spatial resolution of 10×10 km~2,model simulation indicated that an annual average increase of 0.6 Tg C yr~(-1)(Tg=10~(12)g) would be possible under the AIB scenario.The NPP in the late 2040s would increase by 5%(30 Tg C) within the 98×10~6 hm~2 cropland area in contrast with that in the early 2000s.A further investigation suggested that changes in the NPP would not be evenly distributed in China.A higher increase would occur in a majority of regions located in eastern and northwestern China,while a slight reduction would appear in Hebei and Tianjin in northern China.The spatial characteristics of the crop NPP change are attributed primarily to the uneven distribution of temperature change.     

Simulating Crop Net Primary Production in China from 2000 to 2050 by Linking the Crop-C model with a FGOALS＇s Model Climate Change Scenario

Net primary production （NPP） of crop represents the capacity of sequestrating atmospheric CO2 in agro-ecosystem, and it plays an important role in terrestrial carbon cycling. By linking the Crop-C model with climate change scenario projected by a coupled GCM FGOALS via geographical information system （GIS） techniques, crop NPP in China was simulated from 2000 to 2050. The national averaged surface air temperature from FGOALS is projected to increase by 1.0℃ over this period and the corresponding atmospheric CO2 concentration is 535 ppm by 2050 under the IPCC A1B scenario. With a spatial resolution of 10 ×10 km^2, model simulation indicated that an annual average increase of 0.6 Tg C yr^-1 （Tg=10^12 g） would be possible under the A1B scenario. The NPP in the late 2040s would increase by 5% （30 Tg C） within the 98×10^6 hm^2 cropland area in contrast with that in the early 2000s. A further investigation suggested that changes in the NPP would not be evenly distributed in China. A higher increase would occur in a majority of regions located in eastern and northwestern China, while a slight reduction would appear in Hebei and Tianjin in northern China. The spatial characteristics of the crop NPP change are attributed primarily to the uneven distribution of temperature change.     

FGOALS-g模式及其参与CMIP6的方案

为参加第六次国际耦合模式比较计划（CMIP6）和进一步提高模式的模拟能力,大气科学和地球流体力学数值模拟国家重点实验室（LASG）模式团队发展了新一代的格点大气版本的FGOALS-g耦合模式。新版本模式在大气分辨率、海洋网格,以及各分量模式的物理过程等方面都有一定的改进,并正在参与CMIP6最核心的试验以及多个CMIP6模式比较子计划试验。给定CMIP6外强迫,模式在工业革命前参照试验（piControl）和大气模式比较计划（AMIP）试验中模拟的初步结果都比较合理。     

温室效应引起的东亚区域气候变化

用中国科学院大气物理研究所的两层大气和二十层大洋环流模式耦合的海气模式进行了控制试验和瞬变响应试验两个长期积分,并用它们的差异来分析大气中二氧化碳含量加倍所引起的东亚区域的气候变化。二氧化碳加倍以后,东亚年平均温度升高,降水增加,土壤湿度也是增加的,但存在着显著的季节性和区域性的差异。因此,又把东亚分成８个区,来详细探讨二氧化碳增加所引起的区域气候变化。选取了３个具有代表性的气候量：温度、降水和土壤湿度。二氧化碳加倍以后,温度的增加和土壤湿度的增加主要出现在冬半年的高纬度,降水增加的最大值也出现在冬半年的高纬度。另外,还初步分析了二氧化碳浓度加倍所引起的温度和降水年际变率的变化     

气候增暖对热带大气季节内振荡能量传播的影响研究

针对近百年来气候增暖这一观测事实,探讨了气候增暖背景下热带大气季节内振荡(ISO)能量传播的长期变化问题。利用56年的NCAR/NCEP再分析资料、中国科学院大气物理研究所大气科学和地球流体力学数值拟国家重点实验室发展的耦合气候模式FGOALS1.0_g的60年数值模拟结果,采用时空谱方法对比分析了实测资料、模式的控制试验和CO21%等比增加的模拟结果。实测资料分析得出:气候增暖将导致热带大气ISO东传波能量相对增强,西传波能量相对减弱。数值模拟结果分析证实是CO2持续增加导致了气候增暖,同时它也是热带大气ISO东传波能量增强西传波能量减弱的主要原因。     

海洋环流的长期变化和预估

IPCC第六次评估报告(AR6)于2021年8月在IPCC第一工作组第14次联合大会上得到审议通过,并得到了IPCC第54届全会接受和批准.文中主要对该报告第九章"海洋、冰冻圈和海平面"中与海洋环流的相关评估内容进行解读.与以前的IPCC报告相比,AR6进一步确认人类活动对海洋环流的影响,并基于最新的数值模式给出对未来...     

暖池季节变化的数值模拟及其对海表热力和动力强迫的敏感性

对比3套不同来源的海表热通量和风应力资料在热带太平洋和印度洋区域的差异,然后把这些海表强迫场作为一个全球海洋环流模式(LICOM)的上边界条件,进行动力和热力强迫的敏感性试验.通过对比分析试验结果,评估了LICOM对印度洋和西太平洋暖池季节变化的模拟能力,探讨了印度洋和西太平洋暖池对动力和热力强迫的敏感性.首先,模式结果表明LICOM能较真实地模拟出印度洋和西太平洋暖池面积和强度的季节变化特征以及两海区暖池季节变化的差异,而且上层海洋垂向分层的加密能有效改善混合层深度季节变化的模拟.其次,模式中暖池的季节变化基本由海表净热通量和混合层深度的季节变化共同决定,但是试验结果中难以反映垂向挟卷和湍流混合对暖池区混合层深度的影响,可能原因是气候态月平均强迫场时间分辨率较粗,不能真实反映一些重要的天气尺度过程对混合层动力过程的影响,故有必要增加强迫场时间分辨率做进一步研究.最后,不同强迫场的敏感性试验对比分析结果表明,印度洋暖池对海表动力和热力强迫场的差异均较为敏感,而西太平洋暖池则只对海表热量强迫场的差异较为敏感,对动力强迫场的差异不敏感.