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黑河实验(HEIFE)──对干旱地区陆面过程的一些新认识 总被引：63，自引：2，他引：63
综合介绍“黑河地区地气相互作用野外观测实验研究（ＨＥＩＦＥ）”的概况。系统分析干旱地区陆面过程的一些基本问题，它们是：（１）干旱地区地表面热量平衡的基本特征：干旱地区蒸发量很小，地表热量平衡中以感热为主．潜热可以忽略不计。（２）干旱地区陆面过程参数化问题：干旱地区能量和物质湍流输送的参数化必须考虑层结影响，否则将造成严重误差。（３）干旱地区一种特殊现象──绿洲与沙漠环境的相互作用：绿洲的“冷岛效应”和临近绿洲沙漠或戈壁的“逆湿现象”是这种相互作用的结果。这些研究结果将加深我们对干旱地区陆面过程的认识。 相似文献
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绿洲效应的模拟及内外因子的敏感性实验 总被引：7，自引：2，他引：5
利用一个已发展的陆面物理过程参数化方案与大气边界层数值模式耦合,模拟了半干旱区绿洲戈壁非均匀下垫面的陆面物理过程及其与大气边界层的相互作用,成功地描绘了绿洲戈壁局地气候效应,并进行了绿洲戈壁局地气候效应对于降水、绿洲水平尺度和植被结构等若干内外因子的敏感性实验.结果表明:绿洲的最小临界尺度为5～10 km之间,最大临界尺度为55～65 km之间,而最利于绿洲维持的尺度范围为20 km左右,这一结论与我国西部地区现存的绿洲尺度统计结果十分一致;绿洲植被覆盖率为0.6左右时,最利于绿洲发展.另外对植被空间分布方式和绿洲植被组成比例上也进行了数值实验,并对影响绿洲生存和持续发展的内、外因子气候效应的影响力量级进行了分级.这些结果对于深入了解绿洲气候的形成和维持机理具有重要的意义. 相似文献
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总结了水平非均匀下垫面的大气边界层研究,指出干旱区的绿洲具有明显的“冷湿岛效应”,并可形成边缘逆湿和区域环流,而植被和水域的分布则显著改变了大气边界层结构．阐述了复杂地形下垫面对局地风场和小尺度环流产生的影响、城市热岛效应的产生及特点和城市中绿地和水体的微气候效应．比较分析了不同陆面参数化方案以及边界层气候模式,提出未来在热力与动力非均匀的结合、湿地下垫面的数值模拟、城市复杂下垫面参数化以及气候模式的耦合等方面尚需进行深入的研究． 相似文献
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黑河实验（HEIFE）的一些研究成果 总被引：49，自引：23，他引：49
本文回顾了黑河实验（ＨＥＩＦＥ）的执行情况，总结了到目前为止的主要研究成果。得到了干旱地区陆面过程地表参数、地表能量平衡特征和湍流通量参数化的结果。同时得到了干旱地区陆面过程的物理机制同湿润地区有质的差异这一认识：同湿润地区不同，干旱地区地表蒸散和植被过程并不是地表能量平衡中的控制因子，因为感热并不输送到自由大气仅是大气边界层的强迫因子；而潜热输送给自由大气并且潜热的释放是大气环流的主要能源，但干旱地区很少或没有水汽和潜热输送到自由大气，所以干旱地区自由大气不能从地面得到热能；地表反射率大和向上长波辐射强致使净辐射亏损大；基于以上原因，干旱地区可能是一个水汽输送和热能的“汇”。这些结果使我们能更好地理解干旱地区的陆面过程。黑河实验的结果以系统的观测事实证实了绿洲的冷岛效应，临近绿洲沙漠的逆湿现象，即夏季白天常常是绿洲有感热向下输送，临近绿洲的沙漠有水汽向下输送。这些结果揭示了绿洲和沙漠环境相互作用的较完整图像 相似文献
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半干旱区植被覆盖度对边界层气候热力影响的数值模拟 总被引：14，自引：0，他引：14
在陆－气相互作用的中小尺度系统研究中，水平非均匀下垫面的强迫作用是主要的物理过程。本文利用能量闭合二维陆面过程与大气边界层耦合模式，研究了我国西北半干旱地区（３８°Ｎ，１０５°Ｅ）夏季下垫面物理特征的变化对区域边界层气候的影响。结果表明：土壤湿度、植被覆盖度对局地环流和区域边界层气候的形成起着决定性的作用。模拟结果揭示了在半干旱地区大面积植树造林、提高植被覆盖度，可涵养土壤水分，改善局地生态环境，是人工持续改造干旱、半干旱荒漠地区局地气候的重要途径。 相似文献
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非均匀下垫面边界层的观测和数值模拟研究(I):冷岛效应和逆湿现象的完整物理图像 总被引：11，自引：4，他引：7
利用HEIFE、DHEX和GAME/Tibet 3个观测试验和部分常规气象站观测资料,分析了下垫面非均匀条件下产生的冷岛效应和逆湿现象的完整物理图像以及它们对地表能量和五水转化的影响.分析结果表明,下垫面非均匀特征对五水转化有着明显的影响;冷岛效应和逆湿现象是下垫面非均匀性的必然结果,它们在自然界普遍存在;现有陆面过程模式很难刻画冷岛效应和逆湿现象,通常现有陆面过程模式很难将冷岛效应中的热量平流转化成蒸发潜热,同时陆面过程模式也混淆了逆湿现象和发生在下垫面上的大气水的冷却凝结.这些评述将有助于今后非均匀陆面过程的进一步研究. 相似文献
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干旱区绿洲与荒漠相互作用下陆面特征的数值模拟 总被引：25，自引：9，他引：16
用新发展的二维中尺度土壤－植被－大气连续体数值模式,系统地模拟了绿洲与荒漠相互作用下的陆面特征和地表面能量输送特征。这一模拟结果不仅部分地验证了陆面过程野外实验的观测结果。 相似文献
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非均匀下垫面局地气候效应的数值模拟 总被引：18，自引：24，他引：18
使用美国NCAR非静力平衡模式MM 5V3,模拟了黑河地区非均匀下垫面局地小气候效应 ,再现了山谷风环流及夏季“绿洲效应”、沙漠上的“逆湿”和由于地表热力分布不均匀引起的绿洲—沙漠垂直环流等绿洲—沙漠相互作用的典型特征 ,较全面地揭示了非均匀地表大气边界层内的风、温、湿度场与陆面相互作用的物理机理 ,验证了野外实验的结果 相似文献
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为了研究大气环流模式次网格中尺度通量的参数化问题，本文发展了一个Pielke中尺度边界层与陆面过程的耦合模式，陆面过程模式中包括一个简单植被水热传输模式及一个裸土沙漠模式。利用这一耦合模式，对黑河试验区中沙漠和绿洲这种典型的非均匀下垫面进行了模拟，20多个数值试验的模拟结果表明:（1）中尺度通量在特定的情况下具有和湍流通量相当的重要性，因此，大尺度模式中对中尺度通量的参数化是十分必要的。（2）对于中尺度通量的发展存在一个明显的最优尺度和最优块数，即当绿洲尺度为60 km，3块时，中尺度通量最大。而且当块数增加到一定数目时，可以忽略非均匀效应。（3）背景风速的增大可以使中尺度通量减小；粗糙度的试验说明非均匀块之间的热力差异的减小可使中尺度通量非线性地减小。 相似文献
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Observed daily precipitation data from the National Meteorological Observatory in Hainan province and daily data from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis-2 dataset from 1981 to 2014 are used to analyze the relationship between Hainan extreme heavy rainfall processes in autumn (referred to as EHRPs) and 10–30 d low-frequency circulation. Based on the key low-frequency signals and the NCEP Climate Forecast System Version 2 (CFSv2) model forecasting products, a dynamical-statistical method is established for the extended-range forecast of EHRPs. The results suggest that EHRPs have a close relationship with the 10–30 d low-frequency oscillation of 850 hPa zonal wind over Hainan Island and to its north, and that they basically occur during the trough phase of the low-frequency oscillation of zonal wind. The latitudinal propagation of the low-frequency wave train in the middle-high latitudes and the meridional propagation of the low-frequency wave train along the coast of East Asia contribute to the ‘north high (cold), south low (warm)’ pattern near Hainan Island, which results in the zonal wind over Hainan Island and to its north reaching its trough, consequently leading to EHRPs. Considering the link between low-frequency circulation and EHRPs, a low-frequency wave train index (LWTI) is defined and adopted to forecast EHRPs by using NCEP CFSv2 forecasting products. EHRPs are predicted to occur during peak phases of LWTI with value larger than 1 for three or more consecutive forecast days. Hindcast experiments for EHRPs in 2015–2016 indicate that EHRPs can be predicted 8–24 d in advance, with an average period of validity of 16.7 d. 相似文献
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Based on the measurements obtained at 64 national meteorological stations in the Beijing–Tianjin–Hebei (BTH) region between 1970 and 2013, the potential evapotranspiration (ET0) in this region was estimated using the Penman–Monteith equation and its sensitivity to maximum temperature (Tmax), minimum temperature (Tmin), wind speed (Vw), net radiation (Rn) and water vapor pressure (Pwv) was analyzed, respectively. The results are shown as follows. (1) The climatic elements in the BTH region underwent significant changes in the study period. Vw and Rn decreased significantly, whereas Tmin, Tmax and Pwv increased considerably. (2) In the BTH region, ET0 also exhibited a significant decreasing trend, and the sensitivity of ET0 to the climatic elements exhibited seasonal characteristics. Of all the climatic elements, ET0 was most sensitive to Pwv in the fall and winter and Rn in the spring and summer. On the annual scale, ET0 was most sensitive to Pwv, followed by Rn, Vw, Tmax and Tmin. In addition, the sensitivity coefficient of ET0 with respect to Pwv had a negative value for all the areas, indicating that increases in Pwv can prevent ET0 from increasing. (3) The sensitivity of ET0 to Tmin and Tmax was significantly lower than its sensitivity to other climatic elements. However, increases in temperature can lead to changes in Pwv and Rn. The temperature should be considered the key intrinsic climatic element that has caused the "evaporation paradox" phenomenon in the BTH region. 相似文献
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Storms that occur at the Bay of Bengal (BoB) are of a bimodal pattern, which is different from that of the other sea areas. By using the NCEP, SST and JTWC data, the causes of the bimodal pattern storm activity of the BoB are diagnosed and analyzed in this paper. The result shows that the seasonal variation of general atmosphere circulation in East Asia has a regulating and controlling impact on the BoB storm activity, and the “bimodal period” of the storm activity corresponds exactly to the seasonal conversion period of atmospheric circulation. The minor wind speed of shear spring and autumn contributed to the storm, which was a crucial factor for the generation and occurrence of the “bimodal pattern” storm activity in the BoB. The analysis on sea surface temperature (SST) shows that the SSTs of all the year around in the BoB area meet the conditions required for the generation of tropical cyclones (TCs). However, the SSTs in the central area of the bay are higher than that of the surrounding areas in spring and autumn, which facilitates the occurrence of a “two-peak” storm activity pattern. The genesis potential index (GPI) quantifies and reflects the environmental conditions for the generation of the BoB storms. For GPI, the intense low-level vortex disturbance in the troposphere and high-humidity atmosphere are the sufficient conditions for storms, while large maximum wind velocity of the ground vortex radius and small vertical wind shear are the necessary conditions of storms. 相似文献
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The spatial and temporal variations of daily maximum temperature(Tmax), daily minimum temperature(Tmin), daily maximum precipitation(Pmax) and daily maximum wind speed(WSmax) were examined in China using Mann-Kendall test and linear regression method. The results indicated that for China as a whole, Tmax, Tmin and Pmax had significant increasing trends at rates of 0.15℃ per decade, 0.45℃ per decade and 0.58 mm per decade,respectively, while WSmax had decreased significantly at 1.18 m·s~(-1) per decade during 1959—2014. In all regions of China, Tmin increased and WSmax decreased significantly. Spatially, Tmax increased significantly at most of the stations in South China(SC), northwestern North China(NC), northeastern Northeast China(NEC), eastern Northwest China(NWC) and eastern Southwest China(SWC), and the increasing trends were significant in NC, SC, NWC and SWC on the regional average. Tmin increased significantly at most of the stations in China, with notable increase in NEC, northern and southeastern NC and northwestern and eastern NWC. Pmax showed no significant trend at most of the stations in China, and on the regional average it decreased significantly in NC but increased in SC, NWC and the mid-lower Yangtze River valley(YR). WSmax decreased significantly at the vast majority of stations in China, with remarkable decrease in northern NC, northern and central YR, central and southern SC and in parts of central NEC and western NWC. With global climate change and rapidly economic development, China has become more vulnerable to climatic extremes and meteorological disasters, so more strategies of mitigation and/or adaptation of climatic extremes,such as environmentally-friendly and low-cost energy production systems and the enhancement of engineering defense measures are necessary for government and social publics. 相似文献
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《大气和海洋科学快报》2013,(1):67
正AIMS AND SCOPE Atmospheric and Oceanic Science Letters (AOSL) publishes short research letters on all disciplines of the atmosphere sciences and physical oceanography. Contributions from all over the world are welcome.SUBMISSIONAll submitted 相似文献
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<正>With the support of specialized funds for national science institutions,the Guangzhou Institute of Tropical and Marine Meteorology,China Meteorological Administration set up in October 2008 an experiment base for marine meteorology and a number of observation systems for the coastal boundary layer,air-sea flux,marine environmental elements,and basic meteorological elements at Bohe town,Maoming city,Guangdong province,in the northern part of the South China Sea. 相似文献
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《大气和海洋科学快报》2014,7(6):F0003-F0003
AIMS AND SCOPE
Atmospheric and Oceanic Science Letters （AOSL） publishes short research letters on all disciplines of the atmosphere sciences and physical oceanography. Contributions from all over the world are welcome. 相似文献
Atmospheric and Oceanic Science Letters （AOSL） publishes short research letters on all disciplines of the atmosphere sciences and physical oceanography. Contributions from all over the world are welcome. 相似文献
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《大气和海洋科学快报》2014,(5):F0003-F0003
AIMS AND SCOPE Atmospheric and Oceanic Science Letters （AOSL） pub- lishes short research letters on all disciplines of the atmos- phere sciences and physical oceanography. Contributions from all over the world are welcome. 相似文献
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《大气和海洋科学快报》2012,(3):273
正AIMS AND SCOPE Atmospheric and Oceanic Science Letters (AOSL) publishes short research letters on all disciplines of the atmosphere sciences 相似文献