The Simulation of Stratocumulus and Its Impacts on SST:Based on the IAP Near-Term Climate Prediction System     

Guo Zhun  Zhou Tianjun 《地球科学进展》2017,32(4):373-381

The near-term climate prediction system (DecPreS) is built on the initialization of the ocean state, which can be regarded as a full-coupled system with “adjusted” air-sea interactions. The relationship between stratocumulus and Sea Surface Temperature (SST ) is an essential part of air-sea interactions. In this study, we investigated such a relationship in DecPreS of the Institute of Atmospheric Physics, in which the merge of the Ensemble Optimal Interpolation (EnOI) and Incremental Analysis Update (IAU) scheme was employed. EnOI-IAU generally reproduces the spatial pattern of SST and low-clouds. However, the simulated cloud fraction/liquid water path are underestimated while the SST is overestimated in stratocumulus regimes, especially in the subtropical East Pacific and South Ocean. It is partly because the unrealistic air-sea interaction dominates these regions that the underestimated stratocumulus allows more input of incoming shortwave flux (20 W/m²). The deficient stratocumulus is highly related to the unrealistic vertical structure of Atmospheric Boundary Layer (ABL), in which the moisture, temperature and vertical heat transports concentrate at the surface layer. Our results imply that stratocumulus and ABL be important in DecPreS. Clarifying the importance of ABL and stratocumulus will provide a possible way to improve the DecPreS.  相似文献   

Numerical simulation of the effects of fish behavior on flow dynamics around net cage     

《Applied Ocean Research》2017

The computational fluid dynamics study is performed to analyze the impact of the cultured fish on the flow field through net cage and the deformation of net cage. The shear stress turbulent k-omega model is applied to simulate the flow field through the net cage, and the large deformation nonlinear structure model is adopted to conduct the structural analysis of the flexible net cage. To validate the net-fluid interaction model of the net cage in current, a series of physical model tests are conducted, which indicate that the numerical model can accurately simulate the flow field around the net cage and the deformation of the net cage. A fish model is used to simulate the effect of fish behavior on the flow pattern around the net cage and the deformation of the net cage. In addition, the flow fields around the net cage in current are investigated considering different fish group structures, fish swimming speeds, fish distributions and fish stocking densities. The results indicate that the circular movement of fish in the still water leads to a low pressure zone at the center of net cage, which causes a strong vertical flow along the center line of the net cage. The drag force on the net cage is significantly decreased with the increasing fish stocking density, but the most severe deformation of net cage occurred in the case of medium fish stocking density.  相似文献   

南极磷虾资源丰度及其与海冰和表温的关系   总被引：2，自引：0，他引：2       下载免费PDF全文

戴立峰  张胜茂樊伟 《极地研究》2012,24(4):352-360

根据2003—2010年南极磷虾48.2区产量数据结合该区域海冰和SST数据,分析了磷虾产量的时空分布,探讨了海冰和SST对南极磷虾资源丰度的影响。结果表明,48.2区的渔汛期为3—7月,主要作业时间为2—8月,产量约占该渔区年产量的99.3%。回归分析表明,磷虾CPUE变动与海冰和SST面积变化关系明显。磷虾CPUE与海冰总面积年间变化呈现显著的负相关(R=0.80),与海冰密集度为90%—100%的海冰面积负相关系数最大(R=0.84);年内变化关系则为一元二次多项式回归模型,CPUE随海冰面积的递增先增大后减小,与海冰密集度为60%—70%的海冰面积相关系数最大(R=0.94)。磷虾CPUE与SST为-2—3℃时的总面积年间变化负相关性不显著(R=0.46),但与SST为1—2℃时的面积呈现显著的负相关(R=0.91);年内变化关系也为一元二次多项式回归模型,CPUE随SST面积的递增先增大后减小,与SST为0—1℃时的面积相关系数最大(R=0.97)。  相似文献   

西北太平洋热带气旋频数的变化及与海表温度的相关研究   总被引：26，自引：2，他引：24  

杨桂山  施雅风 《地理学报》1999,54(1):22-29

本文根据西北太平洋近４６年（１９４９年～１９９４年）热带气旋和５°×５°经纬网格点月均海表温度系列资料,对西北太平洋热带气旋频数的时空变化及与海表温度之间可能存在的相关关系进行了系统的研究。结果表明：在西北太平洋海域,海表温度偏高对应热带气旋频数也偏多,在２０°Ｎ以北、１４０°Ｅ以西海域偏多趋势更为明显。进一步的相关计算显示,近２５年来（１９７０年～１９９４年）两者之间的各种相关以非线性（指数型）为最佳,以５年滑动平均代表的多年变化之间的相关性远远高于逐年变化,高度显著的相关出现在热带气旋频数多年变化滞后海表温度１年左右。  相似文献   

近五十年来华北地区旱涝特征与全球变化的研究及对未来趋势的探讨   总被引：46，自引：10，他引：36  

孙淑清 《高原气象》1999,18(4):541-551

对近五年华北地区的降水资料进行了时空分析,研究了水资源枯、丰的变迁及它们的地域特征。并对大气环流及海温异常进行了对比分析。结果表明：华北降水距平有明显的二十年左右的年代际变化。从总体上说,从５０年代初至７０年代为丰水期,７０年代至９０年代则为枯水期,而从１９９２年以后又开始变为正距平。这种年代际变化有很强的地域性,个别地区表现出与平均趋势截然不同的变化,对比丰水期和枯水期的环流状态发现,华北地区二  相似文献   

Subtropical high anomalies over the western pacific and its relations to the asian monsoon and sst anomaly   总被引：15，自引：0，他引：15  

Sun Shuqing  Ying Ming 《大气科学进展》1999,16(4):559-568

Using the data of 500 hPa geopotential height from 1951 to 1995, SST roughly in the same period and OLR data from 1974 to 1994, the relation between the anomalies of subtropical high (STH for short) and the tropical circulations including the Asian monsoon as well as the convective activity are studied。 In older to study the physical process of the air-sea interaction related to STH anomaly, the correlation of STH with SST at various sea areas, lagged and simultaneous, has been calculated. Comparing the difference of OLR, wind fields, vertical circulations and SST anomalies in the strong and weak STH, we investigate the characteristics of global circulations and the SST distributions related to the anomalous STH at the western Pacific both in winter and summer. Much attention has been paid to the study of the air-sea interaction and the relationship between the East Asian monsoon and the STH in the western Pacific. A special vertical circulation, related to the STH anomalies is found, which connects the monsoon current to the west and the vertical flow influenced by the SST anomaly in the tropical eastern Pacific.  相似文献   

西太平洋赤道附近海温与中国东南沿海台风关系的初步分析   总被引：7，自引：1，他引：6  

许金镜 《台湾海峡》1998,17(3):278-281

本文对１９６０－１９９６年北太平洋月平均海表温度和中国东南沿海年台风资料的分析素材,初步揭示了两者之间联系。结果表明,西太平洋赤道附近海流区的海表温度不仅在同期具有高与台风多呈正相关关系。而且在前期存在关预测的先兆,特别是秋冬两季更加明显,具有较好的隔季相关关系。经建立预报方程,其趋势拟合率达８１．８％,试报３ａ,并准确率为６６．７％。  相似文献   

气候标准值改变对ENSO事件划分的影响   总被引：29，自引：4，他引：25  

李晓燕  翟盘茂  任福民 《热带气象学报》2005,21(1):72-78

分析了华南、长江流域和华北夏季风三雨带降水的年代际变化特征及其与海气系统的关系。结果表明,三雨带的开始日、结束日都有明显的年代际变化特征,主要表现为自1990年代至今,三雨带开始日推迟,华北雨带终止日明显提前。夏季风的进程与两极涛动密切相关,也与局地海陆热力差异有关：长江流域降水对应于欧亚大陆的位势高度正异常,而华南和华北降水都对应于欧亚大陆的位势高度负异常。华南、华北降水与北太平洋中纬度SST年代际变率密切相关,而长江流域降水与北大西洋中高纬度和西太平洋暖池SST的年代际变率有关。这说明年代际时间尺度上,夏季风进程的不同阶段对应着显著的环流和海温差别,中高纬的环流和海温对夏季风降水有重要的影响。  相似文献   

THE IMPACT OF PRECEDING ATMOSPHERIC CIRCULATION AND SST VARIATION ON FLOOD SEASON RAINFALL IN YUNNAN   总被引：1，自引：1，他引：0  

严华生  鲁亚斌  程建刚  段鹤  杨素雨 《热带气象学报(英文版)》2005,11(2):121-130

Spatial and temporal distribution characteristics and scale range of two significant areas were obtained by analyzing the relationship among summer rainfall in Yunnan province, height field and SST field (40°S – 40°N, 30 °E – 70°W) across the North Hemisphere at 200 hPa, 500 hPa and 850 hPa for Jan. to May and correlation, and field wave structure. Remote key regions among summer rainfall in Yunnan province, height field and SST field (40°S – 40°N, 30°E – 70°W) across the North Hemisphere at 200 hPa, 500 hPa and 850 hPa were studied through further analyzing of the circulation system and its climate / weather significance. The result shows that the forecast has dependable physical basis when height and SST fields were viewed as predictors and physical models of impacts on rainy season precipitation in Yunnan are preliminarily concluded.  相似文献   

The Onset of the Monsoon over the Bay of Bengal: The Year-to-Year Variations          下载免费PDF全文

YU Wei-Dong  LI Kui-Ping  SHI Jian-Wei  LIU Lin  WANG Hui-Wu  LIU Yan-Liang 《大气和海洋科学快报》2012,5(4):342-347

In situ buoy observation data spanning four years(2008-2011) were used to demonstrate the year-to-year variations of the monsoon onset processes in the Bay of Bengal(BoB).A significant early(late) monsoon onset event in 2009(2010) was analyzed in detail.It is found that the year-to-year variations of monsoon onset can be attributed to either the interannual variability in the BoB SST or the irregular activities of the intra-seasonal oscillation(ISO).This finding raises concern over the potential difficulties in simulating or predicting the monsoon onset in the BoB region.This uncertainty largely comes from the unsatisfactory model behavior at the intra-seasonal time scale.  相似文献