基于CERES资料的东亚地区单层卷云物理特性时空分布特征

利用2003-2016年的CERES SSF（Clouds and the Earth"s Radiant Energy System Single Scanner Foorprint） 数据，对东亚不同区域的单层卷云物理特性进行研究。结果表明：（1）单层卷云量在东亚地区为25％-46％，低值区分布在青藏高原和云贵高原；单层卷云云厚多为1.2-2.4 km，除南部地区外，东亚其他区域的单层卷云在冬季较厚。（2）东亚地区单层卷云冰粒子等效半径范围集中在22-32 μm，东部海域年平均值在14年中均为最大。冰水柱含量范围集中在12-30 g/m2，西部地区为主要高值区，14年的年平均值均大于24 g/m2。（3）单层卷云光学厚度的高值区（1.7-2.1）分布在青藏高原及其附近，低值多出现在西太平洋上空。东亚五个子区域的云光学厚度均在春季较大。     

东亚地区闪电产生Nox的时空分布特征

利用NASA提供的2.5°×2.5°卫星闪电格点资料(1995-2002年), 并根据纬度区分云闪和地闪后, 对东亚地区(75°～155°E, 0°～55°N)闪电产生NOX的时空分布进行分析, 结果表明 闪电产生的NOX在东亚地区的年总产量平均值为2.30 Tg, 自南向北存在7个极值中心, 它们分别集中于南部、中部和北部极值群内, 三个极值群的最大值分别为16.4, 12.7和5.46 Bg/grid/yr.与该地区NOX的非闪电排放源相比较, 闪电产生NOX的分布范围大, 年产量约为非闪电源年排放总量的23.闪电产生NOX的量在夏季最大, 其区域性特征很明显.地球表面特性的差异造成了闪电产生的NOX在经度分布上存在较大的不平衡性.在气候冷暖交替月份的中低纬度地区闪电产生NOX的增加对强雷暴活动年闪电产生NOX的贡献最为明显.     

序言

燕山期构造运动在我国东部影响广泛。1926年翁文灏先生提出“燕山运动”,最早发现于燕山地区侏罗纪–白垩纪地层之间的不整合界面,逐步扩展到中国东部,甚至整个东亚地区,反映出晚中生代一次重大构造事件。随着我国地质学家们对燕山运动研究的不断深化,认识和理解也在逐渐提升。当前普遍认为燕山期构造运动是继晚三叠世东亚各大陆碰撞对接之后又一次重大地质构造事件,起始于中侏罗世,结束于晚白垩世(约170~80 Ma)。     

东亚地区MIS 5时期孢粉记录的植被与气候研究进展

末次间冰期(深海氧同位素5阶段,MIS 5,71~128 ka BP)离现代间冰期最近,对其认识有助于预测未来环境,而化石孢粉是恢复古植被与古气候的重要指标。通过对选择出的东亚地区孢粉记录的具有年代数据和孢粉图谱的古植被和气候研究的综合分析,初步认为:①MIS 5的植被格局可与现代间冰期即全新世的植被格局对比。②各区孢粉记录了MIS 5气候波动,部分地区可划分出5a,5b,5c,5d和5e,存在轨道尺度变化,千年尺度事件较少发现。③东亚季风是影响现代东亚季风区环境的主要因素,但日本可能还受到西风环流和洋流的影响;西风、印度季风和地形是影响青藏高原环境的主要因素。④东亚地区,特别是干旱半干旱区,分辨率较高的孢粉记录的环境变化仍需更深入的研究。     

Evaluation of spring persistent rainfall over East Asia in CMIP3/CMIP5 AGCM simulations

The progress made fi＇om Phase 3 to Phase 5 of the Coupled Model Intercomparison Project （CMIP3 to CMIP5） in simulating spring persistent rainfall （SPR） over East Asia was examined from the outputs of nine atmospheric general circulation models （AGCMs）. The majority of the models overestimated the precipitation over the SPR domain, with the mean latitude of the SPR belt shifting to the north. The overestimation was about 1mm d-1 in the CMIP3 ensemble, and the northward displacement was about 3°, while in the CMIP5 ensemble the overestimation was suppressed to 0.7 mm d-i and the northward shift decreased to 2.5°. The SPR features a northeast-southwest extended rain belt with a slope of 0.4°N/°E. The CMIP5 ensemble yielded a smaller slope （0.2°N/°E）, whereas the CMIP3 ensemble featured an unre- alistic zonally-distributed slope. The CMIP5 models also showed better skill in simulating the interannual variability of SPR. Previous studies have suggested that the zonal land-sea thermal contrast and sensible heat flux over the southeastern Tibetan Plateau are important for the existence of SPR. These two ther- mal factors were captured well in the CMIP5 ensemble, but underestimated in the CMIP3 ensemble. The variability of zonal land-sea thermal contrast is positively correlated with the rainfall amount over the main SPR center, but it was found that an overestimated thermal contrast between East Asia and South China Sea is a common problem in most of the CMIP3 and CMIP5 models. Simulation of the meridional thermal contrast is therefore important for the future improvement of current AGCMs.     

Spring Indian Ocean-western Pacific SST contrast and the East Asian summer rainfall anomaly

studying the relationship between SST in the tropical Indian Ocean （TIO）, tropical western Pacific （TWP）, and tropical eastern Pacific （TEP） and East Asian summer rainfall （EASR）, using data provided by NOAA/OAR/ESRL PSD and the National Climate Center of China for the period 1979-2008, an index, SSTDI, was defined to describe the SST difference between the TIO and TWP. In comparison with the winter ENSO, the spring SST contrast between the TIO and TWP was found to be more significantly associated with summer rainfall in East Asia, especially along the EASR band and in Northeast China. This spring SST contrast can persist into summer, resulting in a more significant meridional teleconnection pattern of lower-tropospheric circulation anomalies over the western North Pacific and East Asia. These circulation anomalies are dynamically consistent with the summer rainfall anomaly along the EASR band. When the SSTDI is higher （lower） than normal, the EASR over the Yangtze River valley, Korea, and central and southern Japan is heavier （less） than normal. The present results suggest that this spring SST contrast can be used as a new and better predictor of EASR anomalies.     

Evaluation of East Asian climatology as simulated by seven coupled models

Using observation and reanaiysis data throughout 1961-1990, the East Asian surface air temperature, precipitation and sea level pressure climatology as simulated by seven fully coupled atmosphere-ocean models, namely CCSR/NIES, CGCM2, CSIRO-Mk2, ECHAM4/OPYC3, GFDL-R30, HadCM3, and NCARPCM, axe systematically evaluated in this study. It is indicated that the above models can successfully reproduce the annual and seasonal surface air temperature and precipitation climatology in East Asia, with relatively good performance for boreal autumn and annual mean. The models‘ ability to simulate surface air temperature is more reliable than precipitation. In addition, the models can dependably capture the geographical distribution pattern of annual, boreal winter, spring and autumn sea level pressure in East Asia. In contrast, relatively large simulation errors axe displayed when simulated boreal summer sea level pressure is compaxed with reanalysis data in East Asia. It is revealed that the simulation errors for surface air temperature, precipitation and sea level pressure axe generally large over and around the Tibetan Plateau. No individual model is best in every aspect. As a whole, the ECHAM4/OPYC3 and HadCM3 performances axe much better, whereas the CGCM2 is relatively poorer in East Asia. Additionally, the seven-model ensemble mean usually shows a relatively high reliability.     

An Index Measuring the Interannual Variation of the East Asian Summer Monsoon ——The EAP Index

Based on the EAP (East Asia/Pacific) teleconnection in the summer circulation anomalies over ther Northern Hemisphere, an index measuring the strength of the East Asian summer monsoon, i.e., the so-called EAP index, is defined in this paper. From the analyses of observed data, it is clearly shown that the EAP index defined in this study can well describe the interannual variability of summer rainfall and surface air temperature in East Asia, especially in the Yangtze River valley and the Huaihe River valley, Korea,and Japan. Moreover, this index can also reflect the interannual variability of the East Asian summer monsoon system including the monsoon horizontal circulation and the vertical-meridional circulation cell over East Asia. From the composite analyses of climate and monsoon circulation anomalies for high EAP index and for low EAP index, respectively, it is well demonstrated that the EAP index proposed in this study can well measure the strength of the East Asian summer monsoon.     

东亚地区硫酸盐气溶胶间接辐射和气候效应的数值模拟研究

本文利用发展的RIEMS对硫酸盐气溶胶第一间接辐射强迫及其气候效应进行了研究.同卫星观测和其它模式模拟结果对比表明,RIEMS能比较好地模拟云和辐射过程.东亚地区硫酸盐气溶胶的第一间接辐射强迫为负并有明显的季节变化,各季节分别为:冬季-0.88 W/m2,春季-2.27 W/m2,夏季-2.41 W/m2,秋季-1.4...     

2002年夏季东亚地区环流20—30 d主振荡型延伸期预报研究

用2002年3-9月逐日东亚地区850 hPa经向风场资料建立主振荡预测模型(POP),对影响长江下游地区强降水过程的主要低频经向风场(20-30 d时间尺度)的时空变化进行10-30 d延伸期独立预报试验.试验结果表明,在夏半年135次预测中提前20 d预报的相关预报技巧在0.50以上,很好地预报了夏季3次强降水过程对应的经向风的低频变化过程.对20-30 d振荡显著的多年资料预报试验表明,这些预测模型是预报低频环流时空演变的有效工具,对于提高未来3-4周长江下游强降水过程的预报准确率有重要意义.