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1.
Huang Ruixin 《中国海洋大学学报(英文版)》2005,4(4):277-287
Oceanic contribution to the poleward heat flux in the climate system includes two components: the sensible heat flux and the
latent heat flux. Although the latent heat flux has been classified as atmospheric heat flux exclusively, it is argued that
oceanic control over this component of poleward heat flux should play a critically important role. The so-called swamp ocean
model practice is analyzed in detail, and the critical role of oceanic circulation in the establishment of the meridional
moisture transport is emphasized. 相似文献
2.
We analyzed interdecadal variability of the South China Sea monsoon and its relationship with latent heat flux in the Pacific Ocean, using NCEP wind field and OAFlux heat flux datasets. Results indicate that South China Sea monsoon intensity had an obvious interdecadal variation with a decreasing trend. Variability of the monsoon was significantly correlated with latent heat flux in the Kuroshio area and tropical Pacific Ocean. Variability of latent heat flux in the Kuroshio area had an interdecadal increasing trend, while that in the tropical Pacific Ocean had an interdecadal decreasing trend. Latent heat flux variability in these two sea areas was used to establish a latent heat flux index, which had positive correlation with variability of the South China Sea monsoon. When the latent heat flux was 18 months ahead of the South China Sea monsoon, the correlation coefficient maximized at 0.58 (N=612), with a 99.9% significance level of 0.15. Thus, it is suggested that latent heat flux variability in the two areas contributes greatly to interdecadal variability of the South China Sea monsoon. 相似文献
3.
本文以三峡库区腹地的部分地区为典型样带,利用遥感数据的时效性和区域性优势,结合常规气象数据,定量反演样带地表潜热通量,并对比验证遥感反演方法的可行性和可靠性。结果表明：潜热通量在不同地表覆被状况下呈现较大差异,城镇居民区和无植被覆盖区一般在20~80W·m-2;人工林场、山区森林及草灌和山前农作区在180~280W·m-2;水体则分布在420~470W·m-2,潜热通量整体呈现出随地表覆被变化而变化的空间异质性。此外,由于库区地表覆被类型多样,并受到山区起伏地形地貌的影响,潜热通量在空间分布上的地形分异特征也较显著。 相似文献
4.
The South China Sea (SCS) is significantly influenced by El Niño and the Southern Oscillation (ENSO) through ENSO-driven atmospheric and oceanic changes. We analyzed measurements made from 1960 to 2004 to investigate the interannual variability of the latent and sensible heat fluxes over the SCS. Both the interannual variations of latent and sensible heat fluxes are closely related to ENSO events. The low-pass mean heat flux anomalies vary in a coherent manner with the low-pass mean Southern Oscillation Index (SOI). Time lags between the heat flux anomalies and the SST anomalies were also studied. We found that latent heat flux anomalies have a minimum value around January of the year following El Niño events. During and after the mature phase of El Niño, a change of atmospheric circulation alters the local SCS near-surface humidity and the monsoon winds. During the mature phase of El Niño, the wind speed decreases over the entire sea, and the air-sea specific humidity difference anomalies decreases in the northern SCS and increases in the southern SCS. Thus, a combined effect of wind speed anomalies and air-sea specific humidity difference anomalies results in the latent heat flux anomalies attaining minimum levels around January of the year following an El Niño year. 相似文献
5.
Analysis of sensible heat flux(Qh),latent heat flux(Qe),Richardson number(Ri),bulk transport coefficient(Cd) and katabatic winds are presented by using the meteorological data in the near surface layer from an automatic weather station(AWS) in Princess Elizabeth Land,East Antarctica ice sheet and the data of corresponding period at Zhongshan station in 2002.It shows that annual mean air temperature at LGB69 is-25.6°C,which is 16.4°C lower than that at Zhongshan,where the elevation is lower and located on the coast.The temperature lapse rate is about 1.0°C/110 m for the initial from coast to inland.The turbulence heat flux at LGB69 displays obvious seasonal variations with the average sensible heat flux-17.9 W/m2 and latent heat flux-0.9 W/m2.The intensity(Qh Qe) of coolling source is-18.8 W/m2 meaning the snow surface layer obtains heat from atmosphere.The near surface atmosphere is near-neutral stratified with bulk transport coefficients(Cd) around 2.8×10-3,and it is near constant when the wind speed higher than 8 m/s.The speed and the frequency of easterly Katabatic winds at LGB69 were higher than that at Zhongshan Station. 相似文献
6.
With a global GSSTF2 and NCEP/NCAR reanalysis database and observation data at the Yong Xing station of Xisha Island in the South China Sea, we simulated the turbulent sensible and latent heat flux at sea surface in Chinese and neighboring seas (hereafter termed as China seas) using a common bulk method with some improved parameters. Comparing the simulated results with the observed and reanalyzed data, the improvement yielded higher accuracy, a smaller mean square deviation within 10 W/m2, and a smaller average relative error at about 25%. In addition, spatial resolution was improved to 0.1°×0.1°. The simulation is able to replay the main features of regional and seasonal variation in turbulent heat fluxes, and also the general pattern of heat flux changes during the summer monsoon outbreak in the South China Sea. 相似文献
7.
卫星热遥感技术在地震预测中应用研究进展 总被引：6，自引：3，他引：3
已有的研究结果表明。许多强地震前存在热异常。异常的表现形式是多种多样的，异常的时空分布与异常区的地质构造、地理环境、季节、天气等因素有关。内陆地区的地震前常产生热红外异常，而沿海地区的地震前则更容易出现潜热通量异常。红外辐射可以通过卫星红外通道的传感器观测到。而潜热通量可以使用微波遥感观测资料计算或红外遥感与地面观测资料联合反演。应用卫星遥感技术研究地震前的热异常虽然目前仍然存在许多问题，但随着技术的进步和研究工作的深入，应该能在地震预测中发挥重要作用。 相似文献
8.
WU Jinkui DING Yongjian WANG Genxu SHEN Yongping Yusuke YAMAZAKI Jumpei KUBOTA 《中国地理科学(英文版)》2006,16(3):243-248
1 Introduction Most of the solar radiation that ecosystem seizes is con- sumed on latent, sensible and soil heat flux. Among them, latent heat flux shares the biggest part (Gutierrez and Meizer, 1994; Ham et al., 1991; Rachidi et al., 1993). The radiation budget and the energy balance are crucial to water conversion and effective water utilization. Also, they are important parts of research of water-saving ag- riculture (Mo et al., 1997). At present, the researches on radiation budget and e… 相似文献
9.
Role of sea ice in air-sea exchange and its relation to sea fog 总被引：1，自引：0，他引：1
Synchronous or quasi-synchronous stereoscopic sea-ice-air comprehensive observation was conducted during the First China Arctic Expedition in summer of 1999. Based on these data, the role of sea ice in sea-air exchange was studied. The study shows that the kinds, distribution and thickness of sea ice and their variation significantly influence the air-sea heat exchange. In floating ice area, the heat momentum transferred from ocean to atmosphere is in form of latent heat; latent heat flux is closely related to floating ice concentration; if floating ice is less, the heat flux would be larger. Latent heat flux is about 21 23.6 W*m-2, which is greater than sensible heat flux. On ice field or giant floating ice, heat momentum transferred from atmosphere to sea ice or snow surface is in form of sensible heat. In the floating ice area or polynya, sea-air exchange is the most active, and also the most sensible for climate. Also this area is the most important condition for the creation of Arctic vapor fog. The heat exchange of a large-scale vapor fog process of about 500000 km2 on Aug. 21 22,1999 was calculated; the heat momentum transferred from ocean to air was about 14.8×109 kW. There are various kinds of sea fog, radiation fog, vapor fog and advection fog, forming in the Arctic Ocean in summer. One important cause is the existence of sea ice and its resultant complexity of both underlying surface and sea-air exchange. 相似文献
10.
双源能量平衡模型（Two Source Energy Balance, TSEB）和双温度差模型（Dual Temperature Difference, DTD）目前已应用于不同的下垫面类型和环境条件下地表蒸散发估算研究,但是由于模型构建理论机理的差异,模型表现会随着下垫面类型和环境条件的变化而有所不同。因此,本研究选取了黑河流域高寒草地、半干旱区灌溉农田以及干旱区河岸林3种下垫面类型地面观测数据,系统分析了DTD模型和TSEB模型的适用性以及主要误差来源。结果表明:① 在瞬时尺度上,DTD模型在高寒草地上估算潜热通量的误差较小,其RMSE为62.00 W/m2,而TSEB模型的RMSE为75.49 W/m2,2个模型的精度会随着植被覆盖度的增加而出现差异;在半干旱区灌溉农田区域,2种模型表现较为一致,但是在干旱区河岸林,2种模型都低估了潜热通量,且模型误差较大;② 在日尺度上,DTD模型和TSEB模型的表现与瞬时尺度表现较为一致,同时2种模型拆分的植被蒸腾比与基于uWUE模型（Water Use Efficiency, uWUE）拆分的结果吻合较好,但DTD模型的表现要优于TSEB模型;③ 相比较DTD模型而言,TSEB模型对地表温度输入误差更为敏感。本研究通过对比DTD模型和TSEB模型在不同下垫面和环境条件的表现,为今后模型优化提供了理论依据。 相似文献
11.
黄河三角洲蒸散的遥感研究 总被引：16，自引：0，他引：16
蒸散是水资源管理的一个重要参数。与传统的蒸散计算方法相比 ,利用遥感进行蒸散研究具有快速、准确、大区域尺度及地图可视化显示等特点。 SEBAL模型是一个应用遥感影像收集到的可见光波段、近红外和热红外波段信息对大区域范围进行蒸散计算的模型 ,它是基于地表能量平衡方程 ,通过计算地表净辐射通量 ,土壤热通量和显热通量 ,最后计算出用于蒸散的潜热通量 ,进而计算出遥感影像拍摄时的瞬时蒸散及当天的总蒸散量。本文利用 SEBAL模型采用 ETM+影像对黄河三角洲进行了遥感蒸散研究 ,并对黄河三角洲的蒸散特点进行了分析。蒸散研究对黄河三角洲水资源的合理利用有潜在的指导意义。 相似文献
12.
Winter climate change and sea ice-atmosphere interaction at high northern latitudes in ERA40 dataset
刘喜迎 《极地研究(英文版)》2006,17(1)
1 IntroductionGreen house gases, such as CO2,CH4, N2O and so on are released to the atmosphereconstantly by human activities. These gases insert positive radiative forcing to the climate.Meanwhile, aerosol, which are also released by human activities, ins… 相似文献
13.
Atmospheric turbulence plays a vital role in the formation and dissipation of fog. However,studies of such turbulence are typically limited to observations with ultrasonic anemometers less than 100 m above ground. Thus,the turbulence characteristics of upper fog layers are poorly known. In this paper,we present 4-layers of data,measured by ultrasonic anemometers on a wind tower about 400 m above the sea surface; we use these data to characterize atmospheric turbulence atop a heavy sea fog. Large differences in turbulence during the sea fog episode were recorded. Results showed that the kinetic energy,momentum flux,and sensible heat flux of turbulence increased rapidly during the onset of fog. After onset,high turbulence was observed within the uppermost fog layer. As long as this turbulence did not exceed a critical threshold,it was crucial to enhancing the cooling rate,and maintaining the fog. Vertical momentum flux and sensible heat flux generated by this turbulence weakened wind speed and decreased air temperature during the fog. Towards the end of the fog episode,the vertical distribution of sensible heat flux reversed,contributing to a downward momentum flux in all upper layers. Spatial and temporal scales of the turbulence eddy were greater before and after the fog,than during the fog episode. Turbulence energy was greatest in upper levels,around 430 m and 450 m above mean sea level(AMSL),than in lower levels of the fog(390 m and 410 m AMSL); turbulence energy peaked along the mean wind direction. Our results show that the status of turbulence was complicated within the fog; turbulence caused fluxes of momentum and sensible heat atop the fog layer,affecting the underlying fog by decreasing or increasing average wind speed,as well as promoting or demoting air temperature stratification. 相似文献
14.
从地温满足的热传导方程出发，导出了计算土壤平均和瞬时热通量的计算方案。该计算方案可同时计算出土壤热通量随时间和随深度的变化。它利用整层的地温信息来计算任一层的热通量，这种方案克服了用差分方案进行直接计算的局限性。然后使用中日亚洲季风观测实验期间的地温自动观测站资料和相应的常规观测资料，计算了青藏高原上土壤热通量及其变化，结果表明，不论是常规观测站还是自动观测站，其结果与青藏高原第一次观测实验所用热流板的直接观测结果是相近的，因而这种计算方案是实用而有效的。 相似文献
15.
Qu Tang-dong 《中国海洋湖沼学报》1996,14(1):83-90
The general features of the seasonal surface heat budget in the tropical western Pacific Ocean, 20° S–20°N, western boundary
−160°E, were documented by Qu (1995) using a high-resolution general circulation model (GCM, Semtner & Chervin, 1992) and
existing observations. Close inspection of the smaller areas, with the whole region further partitioned into six parts, showed
different mechanisms balance the seasonal surface heat budget in different parts of the region. The results of study on five
subregions are detailed in this article. In the equatorial (3°S–3°N) and North Equatorial Countercurrent (3°N–9°N) region,
the surface heat flux does not change significantly throughout the year, so the surface heat content is determined largely
by vertical motion near the equator and roughly half due to horizontal and half due to vertical circulation in the region
of the North Equatorial Countercurrent (NECC). In the other subrigions (9°N–20°N, 20°S–11°S and 11°S–3°S), however, in addition
to ocean dynamics, surface heat flux can also play a major role in the seasonal variation of sea surface temperature (SST).
The remotely forced baroclinic waves and their effect on the surface heat storage in the model are also investigated. Comparison
with observations indicates that the model wave activities are reasonably realistic.
Contribution No. 2396 from the Institute of Oceanology, Chinese Academy of Sciences.
This study was supported by the Australian CSIRO Division of Oceanography and the National Natural Science Foundation of China
(No. 49176255) 相似文献
16.
1 Introduction TheMadden JulianOscillation (MJO)isastrongatmosphericconvection phenomenonoccurringovertheEasternIndianOceanandtheTropicalWesternPacific,usuallyinregionswithseasurfacetempera tures (SSTs)over 2 9℃ .Theeastwardmovingofalarge scalecirculat… 相似文献
17.
NUMERICAL STUDY ON THE INTERANNUAL OSCILLATION OF SEA SURFACE TEMPERATURE IN THE SOUTH CHINA SEA 总被引：5，自引：0，他引：5
A two and a half layer oceanic model of wind-driven, thermodynamical general circulation is appliedto study the interannual oscillation of sea surface temperature (SST) in the South China Sea (SCS). Themodel consists of two active layers: the upper mixed layer (UML) and the seasonal thermocline, with themotionless abyss beneath them. The governing equations which include momentum, continuity and sea.temperature for each active layer, can describe the physics of Boussinseq approximation, reduced gravityand equatorial β-plane. The formulas for the heat flux at the surface and at the interface between twoactive layers are designed on the Haney scheme. The entrainment and detrainment at the bottom of theUML induces vertical transport of mass,momentum and heat, and couples of dynamic andthermodynamic effect.Using leap-frog integrating scheme and the Arakawa-C grid the model is forced bya time-dependent wind anomaly stress pattern obtained from category analysis of COADS. The numerical results indicate that t 相似文献
18.
We performed a comparison analysis of the variations .in Mercury ( Hg) concentrations and the precipitation proxies ( e. g. , 18 O values and 10 Be concentrations) in the Dome C ice core. The results showed that there were significant correlations between Hg and δ 10O values, 10Be concentrations, indicating that the accumulation rate in Dome C is one of the key factors controlling the variations of Hg concentrations in the past 34 ,000 years, and implying that Hg concentrations in ice core can be used as another reliable proxy of precipitation rate in Antarctica. Based upon the high-resolution δ 18O values, we estimated the variations in mercury deposition flux to Antarctica over the past 34,000 years. The highest mercury deposition flux is about 3. 80 pg cm-2 yr-1 during the Last Glacial Maxium (LGM) as high as 3. 5 times of the mercury deposition flux ( about 1. 08 pg cm -2 yr -1) in Holocene due to the fluctuations in natural mercury emissions such as the oceanic biological emissions. 相似文献
19.
The sensitivity of the global atmospheric and oceanic response to sea surface temperature anomaly (SSTA) throughout the South China Sea (SCS) is investigated using the Fast Ocean-Atmosphere Model (FOAM). Forced by a warming SST, the experiment explicitly demonstrates that the responses of surface air temperature (SAT) and SST exhibit positive anomalous center over SCS and negative anomalous center over the Northern Pacific Ocean (NPO). The atmospheric response to the warm SST anomalies is characterized by a barotropical anomaly in middle-latitude, leading to a weak subtropical high in summer and a weak Aleutian low in winter. Accordingly, Indian monsoon and eastern Asian monsoon strengthen in summer but weaken in winter as a result of wind convergence owing to the warm SST. It is worth noting that the abnormal signals propagate poleward and eastward away in the form of Rossby Waves from the forcing region, which induces high pressure anomaly. Owing to action of the wind-driven circulation, an anomalous anti-cyclonic circulation is induced with a primary southward current in the upper ocean. An obvious cooling appears over the North Pacific, which can be explained by anomalous meridional cold advection and mixing as shown in the analysises of heat budget and other factors that affect SST. 相似文献
20.
半干旱夏季放牧草地能量收支和地表蒸散量变化特征 总被引：1，自引：0，他引：1
以半干旱区域典型夏季放牧草地为研究对象,采用涡动相关法,获取了2012年5月至2013年5月水汽和能量通量观测数据,分析夏季近地层能量收支特征、地表蒸散量变化及其气象控制因子。观测结果显示:生长季有效能量的分配以潜热通量为主,非生长季则以感热通量为主;地表蒸散日总量最大值为3.0mm,日蒸散量大小主要取决于土壤温度、气温和净辐射;降雨量的季节分布是地表蒸散量季节变化的一个重要的影响因子。 相似文献