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1.
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
2.
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
3.
陆面水热通量的准确模拟可为气候模式提供高质量的下边界条件，对气候模拟和预测具有重要意义。本研究基于干旱区张掖国家气候观象台2021年1月-2022年6月和大满灌区绿洲农田站2020年1-12月的观测数据，评估Noah-MP模式对干旱区荒漠和农田两种下垫面的水热通量的模拟性能。结果表明：Noah-MP模式模拟的干旱区荒漠下垫面辐射及感热和潜热通量的变化特征、峰谷值与观测值总体一致，模拟效果较好；模拟的5 cm土壤湿度对降水过程有明显的响应，表现出明显的冷暖季差异，但其模拟性能仍有待改进。Noah-MP模式对干旱区农田下垫面辐射通量及各层土壤温度的模拟效果较理想，但模拟的潜热通量及各层土壤湿度较观测值偏低，尤其在生长季模拟性能并不理想。总体而言，Noah-MP模式对干旱区荒漠下垫面水热通量的模拟性能优于农田下垫面，优化和发展模式水文过程的参数化方案，在模式中考虑人为作用，是提高干旱区陆面过程模式模拟能力的重要方向。 相似文献
4.
利用简化动力学近似分析黑河实验区的感热通量 总被引：3，自引：0，他引：3
本文利用简化动力学近似．运用统计和参数化两种方法分析了黑河实验区的感热通量．结果表明：不稳定条件下绿洲区的感热通量与近地面辐射温度(T3)和空气温度(Ta)之差符合幂定律方程；沙漠地区符合形式为H=f[u(T2-Ta)]的幂定律方程。利用从实验得到的热传输附加阻尼表示式kB^-1=0．2u(T2-Ta)用于对空气动力学阻尼(ra)的参数化，可适用于不同下垫面．并得到了比较满意的感热通量值．最后利用以上结果计算了实验区的潜热通量并做了比较分析。 相似文献
5.
In the paper,the characters of surface energy budget on Huayin(Gobi)and the desert surface during the period from 26 June to 31 August 1990 in the HEIFE have been analyzed,then have been compared with the observed results during 4-19 September 1988 in the Pilot Observation Period of the HEIFE.The results show that the atmosphere is in superadiabatic unstable state and there is a phenomenon of inverse humidity to form negative water vapour flux.The sensible heat flux on the surface energy budget is in majority,but the latent heat flux may be neglected over the Gobi and desert surface in the cloudless daytime in the summer. 相似文献
6.
This paper uses a Modified Soil-Plant-Atmosphere Scheme (MSPAS) to study the interaction betweenland surface and atmospheric boundary layer processes. The scheme is composed of two main parts:atmospheric boundary layer processes and land surface processes. Compared with SiB and BATS, which arefamous for their detailed parameterizations of physical variables, this simplified model is more convenientand saves much more computation time. Though simple, the feasibility of the model is well proved inthis paper. The numerical simulation results from MSPAS show good agreement with reality. The schemeis used to obtain reasonable simulations for diurnal variations of heat balance, potential temperature ofboundary layer, and wind field, and spatial distributions of temperature, specific humidity, vertical velocity,turbulence kinetic energy, and turbulence exchange coefficient over desert and oasis. In addition, MSPAS isused to simulate the interaction between desert and oasis at night, and again it obtains reasonable results.This indicates that MSPAS can be used to study the interaction between land surface processes and theatmospheric boundary layer over various underlying surfaces and can be extended for regional climate andnumerical weather prediction study. 相似文献
7.
鼎新戈壁下垫面近地层小气候及地表能量平衡特征季节变化分析 总被引：4，自引：1，他引：3
利用在甘肃酒泉金塔地区进行的 “绿洲系统能量与水分循环过程观测与数值研究” 野外试验中的鼎新戈壁下垫面近地层2年的微气象观测资料, 分析了鼎新戈壁下垫面近地层小气候和能量平衡特征的季节变化规律。结果表明: 鼎新戈壁地区四季的平均风速在2～6 m/s之间, 没有明显的地方性风, 局地环流和局地相互作用可忽略; 冬季8 m向上比湿梯度垂直减小, 其他季节接近等比湿分布。7月, 典型晴天天气下, 能量平衡各量表现出标准的日循环形态, 白天感热通量峰值达到574 W/m2, 地热流量峰值为101 W/m2, 潜热很小, 在夜间和正午时刻存在负水汽输送现象; 然而降水天气下, 地气之间能量传输却以潜热蒸发为主, 感热很小, 地热流量为负值; 无论晴天和阴天, 地表和浅层 (5 cm和10 cm) 土壤温度都表现为准正弦曲线变化; 与敦煌戈壁相同, 土壤温度的活动层基本在10 cm范围以内, 40 cm以下地温已不存在日变化特征; 降水天气下, 地表和浅层土壤温度有随时间减小的趋势。能量平衡各分量均具有明显的季节变化规律, 感热通量季节平均的峰值在250～400 W/m2之间, 在夏季最大, 冬季最小; 潜热通量季节平均的最大值只有15 W/m2; 地气之间能量传输全年都以感热输送为主; 云和降水使夏季能量平衡各分量与晴天相比减少25％左右, 这种影响程度比极端干旱的敦煌荒漠戈壁地区稍大, 而小于半干旱的陇中黄土高原地区。另外, 在这一地区干旱情况很严重, 夏季的Bowen比极值达到62.4, 季节平均值也高达16.5。 相似文献
8.
Numerical simulation of the critical scale of oasis maintenance and development in the arid regions of Northwest China 总被引：3，自引：0，他引：3
Oasis is a special geographic landscape among the vast desert/Gobi in Northwest China (NWC). The surface sensitive heat flux and latent heat flux at Zhangye Oasis during 1 to 11 August 1991 are simulated using the NCAR nonhydrostatic mesoscale model MM5 Version 3. The horizontal grid resolution is set as 1km. By comparing the simulation results with HEIFE observations, it is proved that the model can be used to simulate the surface energy and water mass exchange of arid and semiarid regions in NWC.Based on the above results, the influence of different oasis scales on the local atmospheric field near the ground surface, and the critical scale of oasis maintenance, in NWC are studied dynamically. The following conclusion is obtained: the local thermal circulation between the oasis and the desert/Gobi is formed in the oasis downstream if the oasis scale is larger than 4 km. This local thermal circulation between the oasis and the desert adjacent to the oasis helps to conserve water vapor over the oasis. At the sametime, it transfers the abundant water vapor from the oasis into the desert/Gobi near to the oasis to supply relatively plentiful water vapor for desert crops to grow on the fringe of the oasis. So, it is advantageous for oasis extension. However, if the scale of the oasis is smaller than 4 km, it is not easy for the local thermal circulation between the oasis and the desert/Gobi to take shape. This study provides a new standpoint for oasis maintenance and development. 相似文献
9.
沙尘气溶胶对半干旱区微气象学特征影响的初步研究 总被引：3，自引：1，他引：2
沙尘气溶胶通过改变地表—大气间的短波及长波辐射从而对地气间热量传输产生影响,进而影响到地表能量收支平衡以及近地面层气象要素的分布。半干旱区是我国干旱化表现最为剧烈的地区,也是沙尘暴频发地区和主要源区之一。本文利用吉林通榆半干旱区国际协调强化观测计划基准站2006年4～6月近地层微气象、地表辐射通量和沙尘气溶胶浓度观测资料,对比分析了该地区在典型沙尘暴天气、扬沙天气和晴朗天气等不同天气状况下近地层各气象要素、地表能量平衡及辐射收支的变化特征。结果表明,沙尘气溶胶对半干旱地区地面微气象学特征及辐射收支具有明显的影响,且表现出不同于干旱区的若干特性:半干旱区沙尘天气下的平均风速比晴天高约2m.s-1,而相对湿度则降低了约35%。相对而言,气温和浅层地温的变化对沙尘的影响响应较弱。半干旱区在沙尘天气时地表净辐射小于晴天,感热/潜热通量分别约占净辐射的55%和30%,分别远大于/远小于晴天时的情形。该地区气溶胶质量浓度与日均感热、相对湿度、潜热等要素具有明显的相关,相关系数分别高达0.70、-0.75和-0.62。相比之下,干旱区沙尘天气时的感热通量要小于晴天时的值,而且气象要素的响应更加剧烈。 相似文献
10.
为检验RAMS模式在金塔地区的模拟性能, 首先选2005年7月2~3日金塔地区的一次晴好天气过程, 然后利用RAMS及MM5模式对该过程进行了48 h三重嵌套的数值模拟, 最后对金塔绿洲、 戈壁及沙漠点近地面各变量的模拟值及实测值进行了对比分析。结果表明： RAMS模式对绿洲、 戈壁和沙漠不同下垫面近地面温度的模拟表现良好, 基本模拟出了近地面相对湿度的日变化趋势, 较好地模拟出了绿洲\_沙漠环流引起的绿洲“冷岛效应”和临近绿洲的戈壁与沙漠上空的“逆湿”现象; RAMS模式对绿洲下垫面潜热通量的模拟比感热通量更接近实况, 而对戈壁和沙漠下垫面感热通量的模拟好于潜热通量, 三种下垫面上净辐射的模拟都与观测值较接近; 同MM5模式的模拟结果比较, RAMS模式对非均匀下垫面净辐射、 感热通量的数值模拟更优于MM5模式。这表明RAMS模式在金塔地区应用的可行性。 相似文献
11.
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
12.
The Surface Energy Budget and Its Impact on the Freeze-thaw Processes of Active Layer in Permafrost Regions of the Qinghai-Tibetan Plateau 总被引：1，自引：0，他引：1
Junjie MA Ren LI Hongchao LIU Zhongwei HUANG Tonghua WU Guojie HU Yao XIAO Lin ZHAO Yizhen DU Shuhua YANG 《大气科学进展》2022,39(1):189-200
The surface energy budget is closely related to freeze-thaw processes and is also a key issue for land surface process research in permafrost regions.In this study,in situ data collected from 2005 to 2015 at the Tanggula site were used to analyze surface energy regimes,the interaction between surface energy budget and freeze-thaw processes.The results confirmed that surface energy flux in the permafrost region of the Qinghai-Tibetan Plateau exhibited obvious seasonal variations.Annual average net radiation(Rn)for 2010 was 86.5 W m-2,with the largest being in July and smallest in November.Surface soil heat flux(G0)was positive during warm seasons but negative in cold seasons with annual average value of 2.7 W m-2.Variations in Rn and G0 were closely related to freeze-thaw processes.Sensible heat flux(H)was the main energy budget component during cold seasons,whereas latent heat flux(LE)dominated surface energy distribution in warm seasons.Freeze-thaw processes,snow cover,precipitation,and surface conditions were important influence factors for surface energy flux.Albedo was strongly dependent on soil moisture content and ground surface state,increasing significantly when land surface was covered with deep snow,and exhibited negative correlation with surface soil moisture content.Energy variation was significantly related to active layer thaw depth.Soil heat balance coefficient K was>1 during the investigation time period,indicating the permafrost in the Tanggula area tended to degrade. 相似文献
13.
SHAW模式的改进及其在黄土高原半干旱区的模拟研究 总被引：1，自引：0，他引：1
陆面过程模拟研究中的一个关键问题是如何准确的计算陆气间能量交换,但现有的陆面过程模式模拟的湍流通量与观测值间仍然存在较大偏差,因此改进湍流通量的参数化方案对于提高陆面过程模式模拟能力有重要意义。本研究通过改进陆面过程模式SHAW中的热力粗糙度方案,以及引入干表层蒸发方案,以期改善湍流通量的模拟能力。在此基础上利用黄土高原半干旱区SACOL站观测资料,进行模式改进前后的单点模拟对比试验,研究其参数化方案改进对陆面过程模拟的影响。结果表明:改进后的SHAW模式能够合理地模拟黄土高原半干旱区陆面特征的变化趋势,模拟值与观测值偏差较小。与原来的SHAW模式模拟结果相比,改进后的SHAW_MOD模式显著提高了湍流通量的模拟能力,并改善了净辐射和深层土壤温度的模拟,但对土壤湿度的改进并不明显,这可能与土壤内部水热传输过程及相关参数化方案有关,还有待做进一步研究。 相似文献
14.
黑河实验区非均匀地表能量通量的数值模拟 总被引：12，自引：13，他引：12
利用三维非静力RAMS模拟研究了黑河实验区非均匀地表能量通量，模拟结果表明：绿洲地表净辐射通量较沙漠戈壁大；绿洲及沙漠戈壁下垫面上的Bowen比分别为0．4和4．0；夜间绿洲上整晚维持蒸发，并有负感热通量。模拟结果与测站实测结果与卫星反演值的对比研究指出，RAMS对绿洲下垫面潜热通量的模拟和沙漠戈壁下垫面感热通量的模拟与实测值基本一致。卫星遥感反演及数值模拟方法对净辐射的估算与实测较吻合，绿洲地表感热通量的卫星反演值较数值模拟结果更接近于实际，但潜热通量的模拟值则较卫星估算值更接近于实际；沙漠戈壁地表则是感热通量的模拟值较卫星反演值更接近于实际。上述分析为今后结合卫星遥感改进RAMS陆面过程参数化，使使用于模拟研究干旱区非均匀下垫面地气相互作用提供了可靠依据。 相似文献
15.
16.
巴丹吉林沙漠不同下垫面辐射特征和地表能量收支分析 总被引：1，自引：0，他引：1
利用2009年夏季在内蒙古自治区阿拉善右旗境内巴丹吉林沙漠开展的"巴丹吉林沙漠陆-气相互作用观测试验"所取得的资料,对比分析了典型晴天条件下,巴丹吉林沙漠两种不同下垫面的辐射平衡特征和地表能量收支的日变化规律。结果表明,不同下垫面地表反射率具有明显的差异,沙漠反射率为0.33,湖区沙生芦苇反射率为0.23,沙漠反射率大于沙生芦苇反射率。巴丹吉林沙漠两种典型下垫面上,各辐射分量均具有相似的日变化特征,即白天大、夜间小。两种下垫面上的净辐射日变化与峰值基本相同,日积分值均约为8MJ.m-2。由于下垫面性质不同,地表能量的分配也不相同。沙漠主要以感热通量为主,地表热流量其次,潜热通量很小可以忽略不计;湖区以潜热通量为主,感热通量和地表热流量次之。 相似文献
17.
The energy budget of the two versions of the GOALS model (GOALS-1.1 and GOALS-2) is described and compared to observational estimates.The results illustrate that the simulated surface net shortwave radiation flux is underestimated in the high-latitude regions while the surface net longwave radiation flux is substantially overestimated in that region,which results in the lower surface air temperature (SAT) of the polar region and the stronger negative sensible heat flux in high latitudes.The overestimated sensible heat flux from surface to atmosphere in the continents causes the much warmer SAT centers,which may be the reason for the bias of the model SAT. The bias that the simulated precipitation is less than observation in most regions is closely related to the underestimated latent heat flux over most of the Eurasian Continent and the oceans, especially over the subtropical oceans.It can be seen that the bias in the OLR of the two models lies in low and middle latitudes,where the absorbed solar shortwave radiation flux at the top of the atmosphere is comparable to the NCEP reanalysis,but much less than ERBE data.This indicates that the improvement of cloud-radiation parameterization scheme in low and middle latitudes is of critical importance to the simulation of global energy budget.The simulated cloud cover from the GOALS-2 model with diagnosed cloud scheme is generally less except at equatorial areas, especially in the mid-latitude areas,which causes the large bias of energy budget there.It is suggested that the refinement of cloud parameterization is one of the most important tasks in the model's future development. 相似文献
18.
Xia Zhang 《Asia-Pacific Journal of Atmospheric Sciences》2012,48(1):97-105
A soil-atmosphere-transfer model (SATM) was evaluated using observational data from the Tongyu Cropland Station and Audubon Research Ranch in semiarid areas, where the land cover was nearly bare soil during the simulation period. Simulations by the SATM at both sites were conducted using the new and original surface thermal roughness length parameterization schemes, respectively. Comparisons of simulations and observations have demonstrated that using the new surface thermal roughness length scheme in this model made sound improvements in the simulation of soil surface temperatures, sensible heat fluxes and net radiation fluxes in the daytime at both sites, compared to the original scheme, because the new scheme produced a larger aerodynamic resistance for turbulent heat transfer in the daytime. With respect to latent heat fluxes, the improvement was not as obvious as that attained for soil surface temperature since the soil water content in the surface layer in a semiarid area is a more important factor than surface soil temperature in controlling evaporation rate. Accordingly, it can be concluded that the new surface thermal roughness length parameterization scheme could improve the ability of the SATM to simulate bare soil surface energy budget with latent heat flux component being innegligible in semiarid areas. 相似文献
19.
黑河地区绿州和沙漠地面辐射收支的若干特征 总被引：10，自引：3，他引：7
利用HEIFE中在绿州和沙漠两个测站所取得的资料。分析了两种不同下垫面辐射收支及其季节变化特征。结果表明：绿州区地表反射率明显小于沙漠区,季节变化明显;地面向上长波辐射绿州小于沙漠,地面有效辐射绿州小于沙漠。且季节变化明显;地表净辐射绿州大于沙漠,其能量以潜热为主输入大气;干旱地区的绿州光合有效辐射年总量大于河北、山声等地。光合有效辐射资源极为丰富。 相似文献
20.
To improve the land surface simulation in the arid and semi-arid areas of northern China,
the observational data from two field experiments in Dunhuang and Tongyu are used to optimize the
parameters in the land surface model, BATS, through calibration with the multicriteria method.
Sensitivity analysis to the parameters in Dunhuang and Tongyu indicates that different parameters
need to be calibrated in two sites with different environmental and climate regimes. Comparison of
observed sensible heat flux, latent heat flux, and ground surface temperature with the simulated
ones shows the simulations with the optimized parameters have been substantially improved. Especially,
the holistic simulations with the calibration of the parameter values are much closer to the
observations in the arid region (Dunhuang), and the energy partition with the calibrated parameters
can also be simulated well in the semi-arid region (Tongyu). Whole results demonstrate that the
parameter calibration of the land surface model is important when the model is to be used to investigate
the land-air interaction. 相似文献