The distinctive conditions present on the north and south slopes of Mount Qomolangma,along with the intricate variations in the underlying surfaces,result in notable variations in the surface energy flux patterns of t...The distinctive conditions present on the north and south slopes of Mount Qomolangma,along with the intricate variations in the underlying surfaces,result in notable variations in the surface energy flux patterns of the two slopes.In this paper,data from TESEBS(Topographical Enhanced Surface Energy Balance System),remote sensing data from eight cloud-free scenarios,and observational data from nine stations are utilized to examine the fluctuations in the surface heat flux on both slopes.The inclusion of MCD43A3 satellite data enhances the surface albedo,contributing to more accurate simulation outcomes.The model results are validated using observational data.The RMSEs of the net radiation,ground heat,sensible heat,and latent heat flux are 40.73,17.09,33.26,and 30.91 W m^(−2),respectively.The net radiation flux is greater on the south slope and exhibits a rapid decline from summer to autumn.Due to the influence of the monsoon,on the north slope,the maximum sensible heat flux occurs in the pre-monsoon period in summer and the maximum latent heat flux occurs during the monsoon.The south slope experiences the highest latent heat flux in summer.The dominant flux on the north slope is sensible heat,while it is latent heat on the south slope.The seasonal variations in the ground heat flux are more pronounced on the south slope than on the north slope.Except in summer,the ground heat flux on the north slope surpasses that on the south slope.展开更多
Dealing with the regional land surfaces heat fluxes over inhomogeneous land surfaces in arid and semi-arid areas is an important but not an easy issue. In this study, one parameterization method based on satellite rem...Dealing with the regional land surfaces heat fluxes over inhomogeneous land surfaces in arid and semi-arid areas is an important but not an easy issue. In this study, one parameterization method based on satellite remote sensing and field observations is proposed and tested for deriving the regional land surface heat fluxes over inhomogeneous landscapes. As a case study, the method is applied to the Dunhuang experimental area and the HEIFE (Heihe River Field Experiment, 1988-1994) area. The Dunhuang area is selected as a basic experimental area for the Chinese National Key Programme for Developing Basic Sciences: Research on the Formation Mechanism and Prediction Theory of Severe Climate Disaster in China (G1998040900, 1999-2003). The four scenes of Landsat TM data used in this study are 3 June 2000, 22 August 2000, and 29 January 2001 for the Dunhuang area and 9 July 1991 for the HEIFE area. The regional distributions of land surface variables, vegetation variables, and heat fluxes over inhomogeneous landscapes in arid and semi-arid areas are obtained in this study.展开更多
The aim of the present paper is to analyze the natural convection heat and mass transfer of nanofluids over a vertical plate embedded in a saturated Darcy porous medium subjected to surface heat and nanoparticle fluxe...The aim of the present paper is to analyze the natural convection heat and mass transfer of nanofluids over a vertical plate embedded in a saturated Darcy porous medium subjected to surface heat and nanoparticle fluxes. To carry out the numerical solution, two steps are performed. The governing partial differential equations are firstly simplified into a set of highly coupled nonlinear ordinary differential equations by appropriate similarity variables, and then numerically solved by the finite difference method. The obtained similarity solution depends on four non-dimensional parameters, i.e., the Brownian motion parameter （Nb）, the buoyancy ratio （Nr）, the thermophoresis parameter （Nt）, and the Lewis number （Le）. The variations of the reduced Nusselt number and the reduced Sherwood number with Nb and Nt for various values of Le and Nr are discussed in detail. Simulation results depict that the increase in Nb, Nt, or Nr decreases the reduced Nusselt number. An increase in the Lewis number increases both of the reduced Nusselt number and the Sherwood number. The results also reveal that the nanoparticle concentration boundary layer thickness is much thinner than those of the thermal and hydrodynamic boundary layers.展开更多
The lack of in situ observations and the uncertainties of the drag coefficient at high wind speeds result in limited understanding of heat flux through the air-sea interface and thus inaccurate estimation of typhoon i...The lack of in situ observations and the uncertainties of the drag coefficient at high wind speeds result in limited understanding of heat flux through the air-sea interface and thus inaccurate estimation of typhoon intensity in numerical models.In this study,buoy observations and numerical simulations from an air-sea coupled model are used to assess the surface heat flux changes and impacts of the drag coefficient parameterization schemes on its simulations during the passage of Typhoon Kalmaegi(2014).Three drag coefficient schemes,which make the drag coefficient increase,level off,and decrease,respectively,are considered.The air-sea coupled model captured both trajectory and intensity changes better than the atmosphere-only model,though with relatively weaker sea surface cooling(SSC)compared to that captured by buoy observations,which led to relatively higher heat flux and thus a stronger typhoon.Different from previous studies,for a moderate typhoon,the coupled simulation with the increasing drag coefficient scheme outputted an intensity most consistent with the observation because of the strongest SSC,reasonable ratio of latent and sensible heat exchange coefficients,and an obvious reduction in the overestimated surface heat flux among all experiments.Results from sensitivity experiments showed that surface heat flux was significantly determined by the drag coefficient-induced SSC rather than the resulting wind speed changes.Only when SSC differs indistinctively(<0.4°C)between the coupled simulations,heat flux showed a weak positive correlation with the drag coefficient-impacted 10-m wind speed.The drag coefficient also played an important role in decreasing heat flux even a long time after the passage of Kalmaegi because of the continuous upwelling from deeper ocean layers driven by the impacted momentum flux through the air-sea interface.展开更多
Based on the method of estimating the diurnal amplitude of sea surface temperature (SST) as a function of daily averaged wind speed, precipitation and peak surface radiation, a parameterization scheme of diurnal cycle...Based on the method of estimating the diurnal amplitude of sea surface temperature (SST) as a function of daily averaged wind speed, precipitation and peak surface radiation, a parameterization scheme of diurnal cycle of SST is developed in the present study. Integrations to National Center for Atmospheric Research (NCAR) Community Climate Model (CCM3), separately forced by observed weekly SSTs with and without diurnal cycle of SST, are compared. Surface observation obtained from the Improved Meteorology (IMET) buoy during TOGA COARE Intensive Observation Period is applied to verify the SST parameterization, as well as a validation to the results from the CCM3 simulation. It is shown that the superposition of diurnal cycle of SST to the forced weekly SST makes a more realistic representation of the surface structure of intraseasonal oscillation over the western Pacific warm pool.展开更多
The change in ocean net surface heat flux plays an important role in the climate system.It is closely related to the ocean heat content change and ocean heat transport,particularly over the North Atlantic,where the oc...The change in ocean net surface heat flux plays an important role in the climate system.It is closely related to the ocean heat content change and ocean heat transport,particularly over the North Atlantic,where the ocean loses heat to the atmosphere,affecting the AMOC(Atlantic Meridional Overturning Circulation)variability and hence the global climate.However,the difference between simulated surface heat fluxes is still large due to poorly represented dynamical processes involving multiscale interactions in model simulations.In order to explain the discrepancy of the surface heat flux over the North Atlantic,datasets from nineteen AMIP6 and eight highresSST-present climate model simulations are analyzed and compared with the DEEPC(Diagnosing Earth's Energy Pathways in the Climate system)product.As an indirect check of the ocean surface heat flux,the oceanic heat transport inferred from the combination of the ocean surface heat flux,sea ice,and ocean heat content tendency is compared with the RAPID(Rapid Climate Change-Meridional Overturning Circulation and Heat flux array)observations at 26°N in the Atlantic.The AMIP6 simulations show lower inferred heat transport due to less heat loss to the atmosphere.The heat loss from the AMIP6 ensemble mean north of 26°N in the Atlantic is about10 W m–2 less than DEEPC,and the heat transport is about 0.30 PW(1 PW=1015 W)lower than RAPID and DEEPC.The model horizontal resolution effect on the discrepancy is also investigated.Results show that by increasing the resolution,both surface heat flux north of 26°N and heat transport at 26°N in the Atlantic can be improved.展开更多
This paper investigates the interannual variation of the West Pacific Subtropical High(WPSH) intensity based on the data compiled by the Chinese National Climate Center.Monthly reanalysis data from National Centers fo...This paper investigates the interannual variation of the West Pacific Subtropical High(WPSH) intensity based on the data compiled by the Chinese National Climate Center.Monthly reanalysis data from National Centers for Environmental Prediction and National Center for Atmospheric Research(NCEP/NCAR) are also used to study the lead-lag relationship between WPSH intensity and surface heat flux anomalies.The three major findings are as follows:First,WPSH intensity presents good seasonal persistence,especially from winter to the ensuing summer.Persistence is more significant after 1977,especially from spring to summer,and from summer to autumn;persistence of anticyclonic anomalies are significantly better than cyclonic anomalies.Second,surface heat flux tends to present opposite anomalous patterns between the strong and weak years of the WPSH intensity,which is especially valid at the latent heat flux over the ocean.Simultaneous correlations between surface heat flux and WPSH intensity in each of the seasons are marked by similar key areas.Finally,surface heat flux from the preceding winter of a strong summer WPSH is quite similar to strong spring WPSH,but the positive anomalies over the northwest Pacific and south of Japan are notably stronger.The situations in the weak years are similar except for those over the northwest Pacific:winter surface heat flux shows negative anomalies for a weak spring WPSH,but positive anomalies for a weak summer WPSH.It is suggested that surface heat flux in the previous winter plays an important role in maintaining the WPSH intensity in the ensuing spring and summer.展开更多
On the basis, of the surface heat fluxes of the Kuroshio key-area (26°-30°N, 125°-30°E)in March andApril, the climatologicai influence of the Kuroshio heat fluxes on meiyu rainfall in the Changjian...On the basis, of the surface heat fluxes of the Kuroshio key-area (26°-30°N, 125°-30°E)in March andApril, the climatologicai influence of the Kuroshio heat fluxes on meiyu rainfall in the Changjiang River (Yangtse River) region are studied. The results are concluded as follows;the surface heat fluxes of the Kuroshio key-area have certain influence on meiyu rainfall in the Changjiang River region during June and July. The correctness rates for the five stations in the Changjing River region (i. e. Wuhan, Jiujiang, Anqing,Nanjing and Shanghai)are in the range of 9/20-13/20. The surface heat fluxes influence mainly on the homogeneous rainfall pattern,the correctness rates come to 7/10-8/10 for the lower valley of the Changjiang River. The estimation expression of the meiyu rainfall for Shanghai consisting of the surface heat flux and the sea surface temperature anomaly of the Kuroshio key area agrees well with the actual meiyu rainfall condition.展开更多
The regional heat flux exchange between heterogeneous landscapes and the nearby surface layer （SL） is a key issue in the study of land-atmosphere interactions over arid areas such as the Heihe River basin in northwe...The regional heat flux exchange between heterogeneous landscapes and the nearby surface layer （SL） is a key issue in the study of land-atmosphere interactions over arid areas such as the Heihe River basin in northwestern China and in high elevation areas such as the Tibetan Plateau. Based on analysis of the land surface heterogeneity and its effects on the overlying air flow, the use of SL observations, atmospheric boundary layer （ABL） observations, and satellite remote sensing （RS） measurements along with three parameterization methodologies （here, termed as the RS, tile, and blending approaches） have been proposed to estimate the surface heat flux densities over heterogeneous landscapes. The tile and blending approaches have also been implemented during HEIhe basin Field Experiment （HEIFE）, the Coordinated Enhanced Observing Period （CEOP） Asia-Australia Monsoon Project on the Tibetan Plateau （CAMP/Tibet）, the Arid Environment Comprehensive Monitoring Plan ＇95 （AECMP＇95）, and the DunHuang Experiment （DHEX）. The results showed that these two proposed parameterization methodologies can be accurately used over heterogeneous land surfaces.展开更多
This work evaluates the performances of climate models in simulating the Southern Ocean(SO)sea surface temperature(SST)by a large ensemble from phases 5 and 6 of the Coupled Model Intercomparison Project(CMIP5 and CMI...This work evaluates the performances of climate models in simulating the Southern Ocean(SO)sea surface temperature(SST)by a large ensemble from phases 5 and 6 of the Coupled Model Intercomparison Project(CMIP5 and CMIP6).By combining models from the same community sharing highly similar SO SST biases and eliminating the effect of global-mean biases on local SST biases,the results reveal that the ensemble-mean SO SST bias at 70°-30°S decreases from 0.38℃ in CMIP5 to 0.28℃ in CMIP6,together with increased intermodel consistency.The dominant mode of the intermodel variations in the zonal-mean SST biases is characterized as a meridional uniform warm bias pattern,explaining 79.1% of the intermodel variance and exhibiting positive principal values for most models.The ocean mixed layer heat budget further demonstrates that the SST biases at 70°-50°S primarily result from the excessive summertime heating effect from surface net heat flux.The biases in surface net heat flux south of 50°S are largely impacted by surface shortwave radiation from cloud and clear sky components at different latitudes.North of 50°S,the underestimated westerlies reduce the northward Ekman transport and hence northward cold advection in models,leading to warm SST biases year-round.In addition,the westerly biases are primarily traced back to the atmosphere-alone model simulations forced by the observed SST and sea ice.These results disclose the thermal origin at the high latitude and dynamical origin at the low latitude of the SO SST biases and underscore the significance of the deficiencies of atmospheric models in producing the SO SST biases.展开更多
Variation in the location of the South Asian High （SAH） in early boreal summer is strongly influenced by elevated surface heating from the Tibetan Plateau （TP） and the Iranian Plateau （IP）. Based on observationa...Variation in the location of the South Asian High （SAH） in early boreal summer is strongly influenced by elevated surface heating from the Tibetan Plateau （TP） and the Iranian Plateau （IP）. Based on observational and ERA-Interim data, diagnostic analyses reveal that the interannual northwestward-southeastwaxd （NW-SE） shift of the SAH in June is more closely correlated with the synergistic effect of concurrent surface thermal anomalies over the TP and IP than with each single surface thermal anomaly over either plateau from the preceding May. Concurrent surface thermal anomalies over these two plateaus in May are characterized by a negative correlation between sensible heat flux over most parts of the TP （TPSH） and IP （IPSH）. This anomaly pattern can persist till June and influences the NW-SE shift of the SAH in June through the release of latent heat （LH） over northeastern India. When the IPSH is stronger （weaker） and the TPSH is weaker （stronger） than normal in May, an anomalous cyclone （anticyclone） appears over northern India at 850 hPa, which is accompanied by the ascent （descent） of air and anomalous convergence （divergence） of moisture flux in May and June. Therefore, the LH release over northeastern India is strengthened （weakened） and the vertical gradient of apparent heat source is decreased （increased） in the upper troposphere, which is responsible for the northwestward （southeastward） shift of the SAH in June.展开更多
Using data from the National Center for Environmental Prediction （NCEP）, the paper analyzed the surface latent heat flux （SLHF） variations for five inland earthquakes occurred in some lake area, moist area and ari...Using data from the National Center for Environmental Prediction （NCEP）, the paper analyzed the surface latent heat flux （SLHF） variations for five inland earthquakes occurred in some lake area, moist area and arid area of China during recent years. We used the SLHF daily and monthly data to differentiate the global and seasonal variability from the transient local anomalies. The temporal scale of the observed variations is 1-2 months before and after the earthquakes, and spatial scale is about 10°×10°. The result suggests that the SLHFs adjacent the epicenters all are anomalous high value （〉μ＋2σ） 8-30 days before the shocks as compared with past several years of data. Different from the abnormal meteorological phenomenon, the distribution of the anomalies was isolated and local, which usually occurred in the epicenter and its adjacent area, or along the fault lines. The increase of SLHF was tightly related with the season which the earthquake occurs in; the maximal （125 W/m^2, Pu＇er earthquake） and minimal （25 W/m^2, Gaize earthquake） anomalies were in summer and winter, respectively. The abundant surface water and groundwater in the epicenter and its adjacent region can provide necessary condition for the change of SLHF. To further confirm the reliability of SLHF anomaly, it is necessary to explore its physical mechanism in depth by more earthquake cases.展开更多
Using the observed monthly precipitation and NCEP (National Centers for Environmental Prediction) reanalysis surface ?ux data from 1951–2000, the connections between the seasonal SSHNF (Surface Sensible Heat Net Fl...Using the observed monthly precipitation and NCEP (National Centers for Environmental Prediction) reanalysis surface ?ux data from 1951–2000, the connections between the seasonal SSHNF (Surface Sensible Heat Net Flux) over the Asian continent and the regional summer precipitation of China were examined. The patterns of collective and individual correlations were identi?ed. The results indicate that the response of the regional summer precipitation of China to the seasonal SSHNF over the study area varies according to region and season. The interannual variability of summer precipitation anomalies over Xinjiang, the northernmost Northeast China, and the North China Plain are most sensitive to the anomaly of the seasonal SSHNF. There are signi?cant collective correlations between the interannual anomalies of the seasonal SSHNF and summer precipitation over these regions. In contrast, the Southeast Tibetan Plateau, Huaihe River Valley, and surrounding areas exhibit the least signi?cant correlation. Signi?cant individual correlations exist between the summer precipitation over the southernmost Northeast China, East Inner Mongolia, South of the Yangtze River and South China and the seasonal SSHNF in certain seasons over the following areas: near Lake Baikal and Lake Balkhash, near Da Hinggan Mountains and Xiao Hinggan Mountains, as well as the Tibetan Plateau.展开更多
On the basis of snow data and AWS (Automatic Weather Station) data obtained from the Tibetan Plateau in recent years (1993 to 1999), the features of sensible heat, latent heat and net long-wave radiations are estimate...On the basis of snow data and AWS (Automatic Weather Station) data obtained from the Tibetan Plateau in recent years (1993 to 1999), the features of sensible heat, latent heat and net long-wave radiations are estimated, and their variations in more-snow year (1997/ 1998) and less-snow year (1996/ 1997) are analyzed comparatively. The relationships between snow cover of the Tibetan Plateau and plateau’s surface heating to the atmospheric heating are also discussed. The difference between more-snow and less-snow year in spring is remarkably larger than that in winter. Therefore, the effect of anomalous snow cover of the Tibetan Plateau in winter on the plateau heating appears more clearly in the following spring of anomalous snow cover. Key words Tibetan Plateau - Snow cover - Effects - Surface heat fluxes This research was supported by the National Key Programme for Developing Basic Sciences G1998040900 (I), National Natural Science Foundation of China (40075018) and Sichuan Youth Science and Technology Fund.展开更多
The decentralized fuzzy inference method(DFIM)is employed as an optimization technique to reconstruct time-and space-dependent heat flux of two-dimensional(2D)participating medium.The forward coupled radiative and con...The decentralized fuzzy inference method(DFIM)is employed as an optimization technique to reconstruct time-and space-dependent heat flux of two-dimensional(2D)participating medium.The forward coupled radiative and conductive heat transfer problem is solved by a combination of finite volume method and discrete ordinate method.The reconstruction task is formulated as an inverse problem,and the DFIM is used to reconstruct the unknown heat flux.No prior information on the heat flux distribution is required for the inverse analysis.All retrieval results illustrate that the time-and spacedependent heat flux of participating medium can be exactly recovered by the DFIM.The present method is proved to be more efficient and accurate than other optimization techniques.The effects of heat flux form,initial guess,medium property,and measurement error on reconstruction results are investigated.Simulated results indicate that the DFIM is robust to reconstruct different kinds of heat fluxes even with noisy data.展开更多
We use the U.S. Navy's Master Oceanographic Observation Data Set (MOODS) forthe Yellow Sea/ East China Sea (YES) to investigate the climatological water mass features and theseasonal and non-seasonal variabilities...We use the U.S. Navy's Master Oceanographic Observation Data Set (MOODS) forthe Yellow Sea/ East China Sea (YES) to investigate the climatological water mass features and theseasonal and non-seasonal variabilities of the thermohaline structure, and use the ComprehensiveOcean-Atmosphere Data Set (COADS) from 1945 to 1989 to investigate the linkage between the fluxes(momentum, heat, and moisture) across the air-ocean interface and the formation of the water massfeatures. After examining the major current systems and considering the local bathymetry and watermass properties, we divide YES into five regions: East China Sea (ECS) shelf, Yellow Sea (YS) Basin,Cheju bifurcation (CB) zone, Taiwan Warm Current (TWC) region, Kuroshio Current (KC) region. Thelong term mean surface heat balance corresponds to a heat loss of 30 W m^(-2) in the ESC and CBregions, a heat loss of 65 W m^(-2) in the KC and TWC regions, and a heat gain of 15 W m^(-2) in theYS region. The surface freshwater balance is defined by precipitation minus evaporation. The annualwater loss from the surface for the five subareas ranges from 1.8 to 4 cm month^(-1). The freshwater loss from the surface should be compensated for from the river run-off. The entire watercolumn of the shelf region (ECS, YS, and CB) undergoes an evident seasonal thermal cycle withmaximum values of temperature during summer and maximum mixed layer depths during winter. However,only the surface waters of the TWC and KC regions exhibit a seasonal thermal cycle.. We also foundtwo different relations between surface salinity and the Yangtze River run-off, namely, out-of-phasein the East China Sea shelf and in-phase in the Yellow Sea. This may confirm an earlier study thatthe summer fresh water discharge from the Yangtze River forms a relatively shallow, low salinityplume-like structure extending offshore on average towards the northeast.展开更多
The temporal and spatial variations of surface latent heat flux(SLHF)and diagnostic air temperature at 2m before and after the M_S5.7 earthquake occurring on November 26,2005 in the area between Ruichang City and Jiuj...The temporal and spatial variations of surface latent heat flux(SLHF)and diagnostic air temperature at 2m before and after the M_S5.7 earthquake occurring on November 26,2005 in the area between Ruichang City and Jiujiang City,Jiangxi Province are summarized in this paper.It is found that before the earthquake significant SLHF anomalies and air temperature anomalies occurred in the epicentral area and its vicinity.The air temperature anomalies appeared from the 2nd to the 13th of November,2005 and were concentrated at the epicentral area and in its southern part.Then two days later,that is,from the 4th to the 15th of November 2005,significant SLHF anomalies occurred in the epicentral area and to its northern area where many lakes are distributed along the active faults.During the anomalous period,the SLHF and air temperature at 2m exceeded the sum of average daily value over 26 years and 1.5 times of its mean square deviation.Both anomalies had maintained for 12 days with a peculiar distribution related to the tectonic active zone.It is considered that both of air temperature anomalies and SLHF anomalies are correlated to the movement of thermal flux from underground prior to earthquake.SLHF anomalies occurred over wide regions covered with abundant water,whereas air temperature anomalies occurred over land.展开更多
On 12 August 2004, Typhoon Rananim （0414） moved inland over China and stagnated over the Poyang Lake area, resulting in torrential rainfall and severe geologic hazards. The Advanced Weather Research and Forecasting ...On 12 August 2004, Typhoon Rananim （0414） moved inland over China and stagnated over the Poyang Lake area, resulting in torrential rainfall and severe geologic hazards. The Advanced Weather Research and Forecasting （ARW-WRF） model and its different land surface models （LSMs） were employed to study the impacts of land surface process on the inland behavior of Typhoon Rananim. Results show that simulations, coupled with LSMs or not, have no significant differences in predicting typhoon track, intensity, and largescale circulation. However, the simulations of mesoscale structure, rainfall rate, and rainfall distribution of typhoon are more reasonable with LSMs than without LSMs. Although differences are slight among LSMs, NOAH is better than the others. Based on outputs using the NOAH scheme, the interaction between land surtace and typhoon was explored in this study. Notably, typhoon rainfall and cloud cover can cool land surface, but rainfall expands the underlying saturated wetland area, which exacerbates the asymmetric distribution of surface heat fluxes. Accordingly, an energy frontal zone may form in the lower troposphere that enhances ascending motion and local convection, resulting in heavier rainfall. Moreover, the expanded underlying saturated wetlands provide plentiful moisture and unstable energy for the maintenance of Typhoon Rananim and increased rainfall in return.展开更多
Four sources of surface heat flux （SHF） and the satellite remote sensing sea surface temperature （SST） data are combined to investigate the heat budget closure of the Huanghai Sea （HS） in winter.It is found that...Four sources of surface heat flux （SHF） and the satellite remote sensing sea surface temperature （SST） data are combined to investigate the heat budget closure of the Huanghai Sea （HS） in winter.It is found that heat loss occurs all over the HS during winter and the area averaged heat content change decreases with a rate of-106 W/m 2.Comparing with the area averaged SHF of-150 W/m 2 from the four SHF data sets,it can be concluded that the SHF plays a dominant role in the HS heat budget during winter.In contrast,the heat advection transported by the Huanghai Warm Current （Yellow Sea Warm Current,HWC） accounted for up to 29% of the HS heat content change.Close correlation,especially in February,between the storm events and the SST increase demonstrates that the HWC behaves strongly as a wind-driven compensation current.展开更多
Variations of sea surface height （SSH） in the Kuroshio south of Japan are addressed by analyzing 19-year （1993-2011） altimetry data from AVISO. Regionally averaged time series of observed SSH had a rising linear t...Variations of sea surface height （SSH） in the Kuroshio south of Japan are addressed by analyzing 19-year （1993-2011） altimetry data from AVISO. Regionally averaged time series of observed SSH had a rising linear trend at 2.64＋0.72 mrn/a in this period. By analyzing the power spectra, several periods were recognized in temporal SSH variations, including those around 90 and 360 days. The seasonal cycle of SSH was minimum in winter （February） and maximum in summer （August）, with peak-to-peak amplitude about 20.0 cm. The spatial distribution of linear trends was inhomogeneous, with a rising linear trend along the coastline and a tripole structure offshore. Spatial distributions of standard deviation of seasonal SSH show very dynamic activities in the southeast of Kyushu and south of Honshu. Seasonal variations of observed SSH are partially explained by surface buoyancy forcing, local wind forcing and the steric component related to subsurface water beneath the mixed layer. Results show different spatial distributions of correlation coefficient and estimation skill between seasonally observed and modeled SSH, which are calculated from surface buoyancy flux, local wind forcing and the steric component related to subsurface water. Of those three, the surface buoyancy flux has a greater contribution to variations of observed SSH on the seasonal time scale south of Japan.展开更多
基金financially supported by the National Natural Science Foundation of China[grant number 42230610]the Second Tibetan Plateau Scientific Expedition and Research(STEP)program[grant number 2019QZKK0103]+1 种基金the Natural Science Foundation of Sichuan Province[grant number 2022NSFSC0217]the Scientific Research Project of Chengdu University of Information Technology[grant number KYTZ201721].
文摘The distinctive conditions present on the north and south slopes of Mount Qomolangma,along with the intricate variations in the underlying surfaces,result in notable variations in the surface energy flux patterns of the two slopes.In this paper,data from TESEBS(Topographical Enhanced Surface Energy Balance System),remote sensing data from eight cloud-free scenarios,and observational data from nine stations are utilized to examine the fluctuations in the surface heat flux on both slopes.The inclusion of MCD43A3 satellite data enhances the surface albedo,contributing to more accurate simulation outcomes.The model results are validated using observational data.The RMSEs of the net radiation,ground heat,sensible heat,and latent heat flux are 40.73,17.09,33.26,and 30.91 W m^(−2),respectively.The net radiation flux is greater on the south slope and exhibits a rapid decline from summer to autumn.Due to the influence of the monsoon,on the north slope,the maximum sensible heat flux occurs in the pre-monsoon period in summer and the maximum latent heat flux occurs during the monsoon.The south slope experiences the highest latent heat flux in summer.The dominant flux on the north slope is sensible heat,while it is latent heat on the south slope.The seasonal variations in the ground heat flux are more pronounced on the south slope than on the north slope.Except in summer,the ground heat flux on the north slope surpasses that on the south slope.
文摘Dealing with the regional land surfaces heat fluxes over inhomogeneous land surfaces in arid and semi-arid areas is an important but not an easy issue. In this study, one parameterization method based on satellite remote sensing and field observations is proposed and tested for deriving the regional land surface heat fluxes over inhomogeneous landscapes. As a case study, the method is applied to the Dunhuang experimental area and the HEIFE (Heihe River Field Experiment, 1988-1994) area. The Dunhuang area is selected as a basic experimental area for the Chinese National Key Programme for Developing Basic Sciences: Research on the Formation Mechanism and Prediction Theory of Severe Climate Disaster in China (G1998040900, 1999-2003). The four scenes of Landsat TM data used in this study are 3 June 2000, 22 August 2000, and 29 January 2001 for the Dunhuang area and 9 July 1991 for the HEIFE area. The regional distributions of land surface variables, vegetation variables, and heat fluxes over inhomogeneous landscapes in arid and semi-arid areas are obtained in this study.
基金Shahid Chamran University of Ahvaz for its support of this paper
文摘The aim of the present paper is to analyze the natural convection heat and mass transfer of nanofluids over a vertical plate embedded in a saturated Darcy porous medium subjected to surface heat and nanoparticle fluxes. To carry out the numerical solution, two steps are performed. The governing partial differential equations are firstly simplified into a set of highly coupled nonlinear ordinary differential equations by appropriate similarity variables, and then numerically solved by the finite difference method. The obtained similarity solution depends on four non-dimensional parameters, i.e., the Brownian motion parameter （Nb）, the buoyancy ratio （Nr）, the thermophoresis parameter （Nt）, and the Lewis number （Le）. The variations of the reduced Nusselt number and the reduced Sherwood number with Nb and Nt for various values of Le and Nr are discussed in detail. Simulation results depict that the increase in Nb, Nt, or Nr decreases the reduced Nusselt number. An increase in the Lewis number increases both of the reduced Nusselt number and the Sherwood number. The results also reveal that the nanoparticle concentration boundary layer thickness is much thinner than those of the thermal and hydrodynamic boundary layers.
基金supported by the National Natural Science Foundation of China under Grant Nos. 41775053, 41976003, and 42192552the National Key Research and Development Program of China under Grant Nos. 2019YFC1510001 and 2019YFC1510102support has been provided by the National Program on Global Change and Air-Sea Interaction (GASI-IPOVAI-04)
文摘The lack of in situ observations and the uncertainties of the drag coefficient at high wind speeds result in limited understanding of heat flux through the air-sea interface and thus inaccurate estimation of typhoon intensity in numerical models.In this study,buoy observations and numerical simulations from an air-sea coupled model are used to assess the surface heat flux changes and impacts of the drag coefficient parameterization schemes on its simulations during the passage of Typhoon Kalmaegi(2014).Three drag coefficient schemes,which make the drag coefficient increase,level off,and decrease,respectively,are considered.The air-sea coupled model captured both trajectory and intensity changes better than the atmosphere-only model,though with relatively weaker sea surface cooling(SSC)compared to that captured by buoy observations,which led to relatively higher heat flux and thus a stronger typhoon.Different from previous studies,for a moderate typhoon,the coupled simulation with the increasing drag coefficient scheme outputted an intensity most consistent with the observation because of the strongest SSC,reasonable ratio of latent and sensible heat exchange coefficients,and an obvious reduction in the overestimated surface heat flux among all experiments.Results from sensitivity experiments showed that surface heat flux was significantly determined by the drag coefficient-induced SSC rather than the resulting wind speed changes.Only when SSC differs indistinctively(<0.4°C)between the coupled simulations,heat flux showed a weak positive correlation with the drag coefficient-impacted 10-m wind speed.The drag coefficient also played an important role in decreasing heat flux even a long time after the passage of Kalmaegi because of the continuous upwelling from deeper ocean layers driven by the impacted momentum flux through the air-sea interface.
基金This study was sponsored by Chinese Academy of Sciences under Grant " Hundred Talents" for" Validation of Coupled Climate Mode
文摘Based on the method of estimating the diurnal amplitude of sea surface temperature (SST) as a function of daily averaged wind speed, precipitation and peak surface radiation, a parameterization scheme of diurnal cycle of SST is developed in the present study. Integrations to National Center for Atmospheric Research (NCAR) Community Climate Model (CCM3), separately forced by observed weekly SSTs with and without diurnal cycle of SST, are compared. Surface observation obtained from the Improved Meteorology (IMET) buoy during TOGA COARE Intensive Observation Period is applied to verify the SST parameterization, as well as a validation to the results from the CCM3 simulation. It is shown that the superposition of diurnal cycle of SST to the forced weekly SST makes a more realistic representation of the surface structure of intraseasonal oscillation over the western Pacific warm pool.
基金supported by the National Natural Science Foundation of China(Grant No.42075036)Fujian Key Laboratory of Severe Weather(Grant No.2021KFKT02)+2 种基金the scientific research start-up grant of Guangdong Ocean University(Grant No.R20001)supported by the University of Reading as a visiting fellowsupported by the UK National Centre for Earth Observation Grant No.NE/RO16518/1。
文摘The change in ocean net surface heat flux plays an important role in the climate system.It is closely related to the ocean heat content change and ocean heat transport,particularly over the North Atlantic,where the ocean loses heat to the atmosphere,affecting the AMOC(Atlantic Meridional Overturning Circulation)variability and hence the global climate.However,the difference between simulated surface heat fluxes is still large due to poorly represented dynamical processes involving multiscale interactions in model simulations.In order to explain the discrepancy of the surface heat flux over the North Atlantic,datasets from nineteen AMIP6 and eight highresSST-present climate model simulations are analyzed and compared with the DEEPC(Diagnosing Earth's Energy Pathways in the Climate system)product.As an indirect check of the ocean surface heat flux,the oceanic heat transport inferred from the combination of the ocean surface heat flux,sea ice,and ocean heat content tendency is compared with the RAPID(Rapid Climate Change-Meridional Overturning Circulation and Heat flux array)observations at 26°N in the Atlantic.The AMIP6 simulations show lower inferred heat transport due to less heat loss to the atmosphere.The heat loss from the AMIP6 ensemble mean north of 26°N in the Atlantic is about10 W m–2 less than DEEPC,and the heat transport is about 0.30 PW(1 PW=1015 W)lower than RAPID and DEEPC.The model horizontal resolution effect on the discrepancy is also investigated.Results show that by increasing the resolution,both surface heat flux north of 26°N and heat transport at 26°N in the Atlantic can be improved.
基金National Basic Research Program of China (2004CB418300 and 2010CB833404)National Natural Science Foundation of China (40675042, 40890054, 40871007 and 40672210)
文摘This paper investigates the interannual variation of the West Pacific Subtropical High(WPSH) intensity based on the data compiled by the Chinese National Climate Center.Monthly reanalysis data from National Centers for Environmental Prediction and National Center for Atmospheric Research(NCEP/NCAR) are also used to study the lead-lag relationship between WPSH intensity and surface heat flux anomalies.The three major findings are as follows:First,WPSH intensity presents good seasonal persistence,especially from winter to the ensuing summer.Persistence is more significant after 1977,especially from spring to summer,and from summer to autumn;persistence of anticyclonic anomalies are significantly better than cyclonic anomalies.Second,surface heat flux tends to present opposite anomalous patterns between the strong and weak years of the WPSH intensity,which is especially valid at the latent heat flux over the ocean.Simultaneous correlations between surface heat flux and WPSH intensity in each of the seasons are marked by similar key areas.Finally,surface heat flux from the preceding winter of a strong summer WPSH is quite similar to strong spring WPSH,but the positive anomalies over the northwest Pacific and south of Japan are notably stronger.The situations in the weak years are similar except for those over the northwest Pacific:winter surface heat flux shows negative anomalies for a weak spring WPSH,but positive anomalies for a weak summer WPSH.It is suggested that surface heat flux in the previous winter plays an important role in maintaining the WPSH intensity in the ensuing spring and summer.
文摘On the basis, of the surface heat fluxes of the Kuroshio key-area (26°-30°N, 125°-30°E)in March andApril, the climatologicai influence of the Kuroshio heat fluxes on meiyu rainfall in the Changjiang River (Yangtse River) region are studied. The results are concluded as follows;the surface heat fluxes of the Kuroshio key-area have certain influence on meiyu rainfall in the Changjiang River region during June and July. The correctness rates for the five stations in the Changjing River region (i. e. Wuhan, Jiujiang, Anqing,Nanjing and Shanghai)are in the range of 9/20-13/20. The surface heat fluxes influence mainly on the homogeneous rainfall pattern,the correctness rates come to 7/10-8/10 for the lower valley of the Changjiang River. The estimation expression of the meiyu rainfall for Shanghai consisting of the surface heat flux and the sea surface temperature anomaly of the Kuroshio key area agrees well with the actual meiyu rainfall condition.
基金under the auspices of the Innovation Projects of the Chinese Academy of Sciences (KZCX2-YW-Q11-01)the Na-tional Natural Science Foundation of China (40825015 and40810059006)+2 种基金the Chinese National Key Programme for Developing Basic Sciences (2005CB422003)the EU-FP7 project "CEOP-AEGIS" (212921)supported by the EC FP6 GMES EA-GLE project (502057) and the International Institute for Geo-Information Science and Earth Observation (ITC), the Netherlands
文摘The regional heat flux exchange between heterogeneous landscapes and the nearby surface layer （SL） is a key issue in the study of land-atmosphere interactions over arid areas such as the Heihe River basin in northwestern China and in high elevation areas such as the Tibetan Plateau. Based on analysis of the land surface heterogeneity and its effects on the overlying air flow, the use of SL observations, atmospheric boundary layer （ABL） observations, and satellite remote sensing （RS） measurements along with three parameterization methodologies （here, termed as the RS, tile, and blending approaches） have been proposed to estimate the surface heat flux densities over heterogeneous landscapes. The tile and blending approaches have also been implemented during HEIhe basin Field Experiment （HEIFE）, the Coordinated Enhanced Observing Period （CEOP） Asia-Australia Monsoon Project on the Tibetan Plateau （CAMP/Tibet）, the Arid Environment Comprehensive Monitoring Plan ＇95 （AECMP＇95）, and the DunHuang Experiment （DHEX）. The results showed that these two proposed parameterization methodologies can be accurately used over heterogeneous land surfaces.
基金supported by the National Natural Science Foundation of China(Nos.42076208,42141019,41831175 and 41706026)the National Key Research and Development Program of China(No.2017YFA0604600)+1 种基金the Natural Science Foundation of Jiangsu Province(No.BK20211209)the Fundamental Research Funds for the Central Universities(Nos.B210202135 and B210201015).
文摘This work evaluates the performances of climate models in simulating the Southern Ocean(SO)sea surface temperature(SST)by a large ensemble from phases 5 and 6 of the Coupled Model Intercomparison Project(CMIP5 and CMIP6).By combining models from the same community sharing highly similar SO SST biases and eliminating the effect of global-mean biases on local SST biases,the results reveal that the ensemble-mean SO SST bias at 70°-30°S decreases from 0.38℃ in CMIP5 to 0.28℃ in CMIP6,together with increased intermodel consistency.The dominant mode of the intermodel variations in the zonal-mean SST biases is characterized as a meridional uniform warm bias pattern,explaining 79.1% of the intermodel variance and exhibiting positive principal values for most models.The ocean mixed layer heat budget further demonstrates that the SST biases at 70°-50°S primarily result from the excessive summertime heating effect from surface net heat flux.The biases in surface net heat flux south of 50°S are largely impacted by surface shortwave radiation from cloud and clear sky components at different latitudes.North of 50°S,the underestimated westerlies reduce the northward Ekman transport and hence northward cold advection in models,leading to warm SST biases year-round.In addition,the westerly biases are primarily traced back to the atmosphere-alone model simulations forced by the observed SST and sea ice.These results disclose the thermal origin at the high latitude and dynamical origin at the low latitude of the SO SST biases and underscore the significance of the deficiencies of atmospheric models in producing the SO SST biases.
基金supported by the National Natural Science Foundation of China (Grant Nos.91437219,41275075 and 41175005)the National Basic Research Program of China (Grant No.2013CB430203)
文摘Variation in the location of the South Asian High （SAH） in early boreal summer is strongly influenced by elevated surface heating from the Tibetan Plateau （TP） and the Iranian Plateau （IP）. Based on observational and ERA-Interim data, diagnostic analyses reveal that the interannual northwestward-southeastwaxd （NW-SE） shift of the SAH in June is more closely correlated with the synergistic effect of concurrent surface thermal anomalies over the TP and IP than with each single surface thermal anomaly over either plateau from the preceding May. Concurrent surface thermal anomalies over these two plateaus in May are characterized by a negative correlation between sensible heat flux over most parts of the TP （TPSH） and IP （IPSH）. This anomaly pattern can persist till June and influences the NW-SE shift of the SAH in June through the release of latent heat （LH） over northeastern India. When the IPSH is stronger （weaker） and the TPSH is weaker （stronger） than normal in May, an anomalous cyclone （anticyclone） appears over northern India at 850 hPa, which is accompanied by the ascent （descent） of air and anomalous convergence （divergence） of moisture flux in May and June. Therefore, the LH release over northeastern India is strengthened （weakened） and the vertical gradient of apparent heat source is decreased （increased） in the upper troposphere, which is responsible for the northwestward （southeastward） shift of the SAH in June.
文摘Using data from the National Center for Environmental Prediction （NCEP）, the paper analyzed the surface latent heat flux （SLHF） variations for five inland earthquakes occurred in some lake area, moist area and arid area of China during recent years. We used the SLHF daily and monthly data to differentiate the global and seasonal variability from the transient local anomalies. The temporal scale of the observed variations is 1-2 months before and after the earthquakes, and spatial scale is about 10°×10°. The result suggests that the SLHFs adjacent the epicenters all are anomalous high value （〉μ＋2σ） 8-30 days before the shocks as compared with past several years of data. Different from the abnormal meteorological phenomenon, the distribution of the anomalies was isolated and local, which usually occurred in the epicenter and its adjacent area, or along the fault lines. The increase of SLHF was tightly related with the season which the earthquake occurs in; the maximal （125 W/m^2, Pu＇er earthquake） and minimal （25 W/m^2, Gaize earthquake） anomalies were in summer and winter, respectively. The abundant surface water and groundwater in the epicenter and its adjacent region can provide necessary condition for the change of SLHF. To further confirm the reliability of SLHF anomaly, it is necessary to explore its physical mechanism in depth by more earthquake cases.
文摘Using the observed monthly precipitation and NCEP (National Centers for Environmental Prediction) reanalysis surface ?ux data from 1951–2000, the connections between the seasonal SSHNF (Surface Sensible Heat Net Flux) over the Asian continent and the regional summer precipitation of China were examined. The patterns of collective and individual correlations were identi?ed. The results indicate that the response of the regional summer precipitation of China to the seasonal SSHNF over the study area varies according to region and season. The interannual variability of summer precipitation anomalies over Xinjiang, the northernmost Northeast China, and the North China Plain are most sensitive to the anomaly of the seasonal SSHNF. There are signi?cant collective correlations between the interannual anomalies of the seasonal SSHNF and summer precipitation over these regions. In contrast, the Southeast Tibetan Plateau, Huaihe River Valley, and surrounding areas exhibit the least signi?cant correlation. Signi?cant individual correlations exist between the summer precipitation over the southernmost Northeast China, East Inner Mongolia, South of the Yangtze River and South China and the seasonal SSHNF in certain seasons over the following areas: near Lake Baikal and Lake Balkhash, near Da Hinggan Mountains and Xiao Hinggan Mountains, as well as the Tibetan Plateau.
基金the National Key Programme for Developing Basic SciencesG1998040900 (I)National Natural Science Foundation of China (400750
文摘On the basis of snow data and AWS (Automatic Weather Station) data obtained from the Tibetan Plateau in recent years (1993 to 1999), the features of sensible heat, latent heat and net long-wave radiations are estimated, and their variations in more-snow year (1997/ 1998) and less-snow year (1996/ 1997) are analyzed comparatively. The relationships between snow cover of the Tibetan Plateau and plateau’s surface heating to the atmospheric heating are also discussed. The difference between more-snow and less-snow year in spring is remarkably larger than that in winter. Therefore, the effect of anomalous snow cover of the Tibetan Plateau in winter on the plateau heating appears more clearly in the following spring of anomalous snow cover. Key words Tibetan Plateau - Snow cover - Effects - Surface heat fluxes This research was supported by the National Key Programme for Developing Basic Sciences G1998040900 (I), National Natural Science Foundation of China (40075018) and Sichuan Youth Science and Technology Fund.
基金Project supported by the Natural Science Foundation of Chongqing(CSTC,Grant No.2019JCYJ-MSXMX0441).
文摘The decentralized fuzzy inference method(DFIM)is employed as an optimization technique to reconstruct time-and space-dependent heat flux of two-dimensional(2D)participating medium.The forward coupled radiative and conductive heat transfer problem is solved by a combination of finite volume method and discrete ordinate method.The reconstruction task is formulated as an inverse problem,and the DFIM is used to reconstruct the unknown heat flux.No prior information on the heat flux distribution is required for the inverse analysis.All retrieval results illustrate that the time-and spacedependent heat flux of participating medium can be exactly recovered by the DFIM.The present method is proved to be more efficient and accurate than other optimization techniques.The effects of heat flux form,initial guess,medium property,and measurement error on reconstruction results are investigated.Simulated results indicate that the DFIM is robust to reconstruct different kinds of heat fluxes even with noisy data.
文摘We use the U.S. Navy's Master Oceanographic Observation Data Set (MOODS) forthe Yellow Sea/ East China Sea (YES) to investigate the climatological water mass features and theseasonal and non-seasonal variabilities of the thermohaline structure, and use the ComprehensiveOcean-Atmosphere Data Set (COADS) from 1945 to 1989 to investigate the linkage between the fluxes(momentum, heat, and moisture) across the air-ocean interface and the formation of the water massfeatures. After examining the major current systems and considering the local bathymetry and watermass properties, we divide YES into five regions: East China Sea (ECS) shelf, Yellow Sea (YS) Basin,Cheju bifurcation (CB) zone, Taiwan Warm Current (TWC) region, Kuroshio Current (KC) region. Thelong term mean surface heat balance corresponds to a heat loss of 30 W m^(-2) in the ESC and CBregions, a heat loss of 65 W m^(-2) in the KC and TWC regions, and a heat gain of 15 W m^(-2) in theYS region. The surface freshwater balance is defined by precipitation minus evaporation. The annualwater loss from the surface for the five subareas ranges from 1.8 to 4 cm month^(-1). The freshwater loss from the surface should be compensated for from the river run-off. The entire watercolumn of the shelf region (ECS, YS, and CB) undergoes an evident seasonal thermal cycle withmaximum values of temperature during summer and maximum mixed layer depths during winter. However,only the surface waters of the TWC and KC regions exhibit a seasonal thermal cycle.. We also foundtwo different relations between surface salinity and the Yangtze River run-off, namely, out-of-phasein the East China Sea shelf and in-phase in the Yellow Sea. This may confirm an earlier study thatthe summer fresh water discharge from the Yangtze River forms a relatively shallow, low salinityplume-like structure extending offshore on average towards the northeast.
基金This research was jointly sponsored by the National 11th"Five-Year Plan"of Key Technology R & D Program of Ministry of Science and Technology (Grant No.2006BAC01B030203)the National Natural Science Foundation of Chin (40372131).
文摘The temporal and spatial variations of surface latent heat flux(SLHF)and diagnostic air temperature at 2m before and after the M_S5.7 earthquake occurring on November 26,2005 in the area between Ruichang City and Jiujiang City,Jiangxi Province are summarized in this paper.It is found that before the earthquake significant SLHF anomalies and air temperature anomalies occurred in the epicentral area and its vicinity.The air temperature anomalies appeared from the 2nd to the 13th of November,2005 and were concentrated at the epicentral area and in its southern part.Then two days later,that is,from the 4th to the 15th of November 2005,significant SLHF anomalies occurred in the epicentral area and to its northern area where many lakes are distributed along the active faults.During the anomalous period,the SLHF and air temperature at 2m exceeded the sum of average daily value over 26 years and 1.5 times of its mean square deviation.Both anomalies had maintained for 12 days with a peculiar distribution related to the tectonic active zone.It is considered that both of air temperature anomalies and SLHF anomalies are correlated to the movement of thermal flux from underground prior to earthquake.SLHF anomalies occurred over wide regions covered with abundant water,whereas air temperature anomalies occurred over land.
基金financed by the National Grand Fundamental Research 973 Program of China (Grant No. 2009CB421504)the Natural Science Foundation of China (Grant Nos. 41175063,40975032,and 41275066)
文摘On 12 August 2004, Typhoon Rananim （0414） moved inland over China and stagnated over the Poyang Lake area, resulting in torrential rainfall and severe geologic hazards. The Advanced Weather Research and Forecasting （ARW-WRF） model and its different land surface models （LSMs） were employed to study the impacts of land surface process on the inland behavior of Typhoon Rananim. Results show that simulations, coupled with LSMs or not, have no significant differences in predicting typhoon track, intensity, and largescale circulation. However, the simulations of mesoscale structure, rainfall rate, and rainfall distribution of typhoon are more reasonable with LSMs than without LSMs. Although differences are slight among LSMs, NOAH is better than the others. Based on outputs using the NOAH scheme, the interaction between land surtace and typhoon was explored in this study. Notably, typhoon rainfall and cloud cover can cool land surface, but rainfall expands the underlying saturated wetland area, which exacerbates the asymmetric distribution of surface heat fluxes. Accordingly, an energy frontal zone may form in the lower troposphere that enhances ascending motion and local convection, resulting in heavier rainfall. Moreover, the expanded underlying saturated wetlands provide plentiful moisture and unstable energy for the maintenance of Typhoon Rananim and increased rainfall in return.
基金The National Natural Science Foundation Project "Sedimentary dynamic mechanism of the Huanghai Warm Current" of China under contract No.40906025the National Natural Science Foundation of China " The process and mechanism of the increasing of surface temperature in the past 30 years in the adjacent seas of China" under contract No.40930844+4 种基金the National Natural Science Foundation of China under contract No.41006002the State Basic Research Program of China under contract No.2010CB428704the Formation and development of the muddy deposition in the central southern Huanghai Sea,and its relation with climate and environmental change of Ocean University of China under contract No.41030856the Scientific Research Fund of the Second Institute of Oceanography,State Oceanic Administration of China under contract No.JT1007the Public Science and Technology Research Funds Projects of Ocean under contract Nos 200905001 and 201005019
文摘Four sources of surface heat flux （SHF） and the satellite remote sensing sea surface temperature （SST） data are combined to investigate the heat budget closure of the Huanghai Sea （HS） in winter.It is found that heat loss occurs all over the HS during winter and the area averaged heat content change decreases with a rate of-106 W/m 2.Comparing with the area averaged SHF of-150 W/m 2 from the four SHF data sets,it can be concluded that the SHF plays a dominant role in the HS heat budget during winter.In contrast,the heat advection transported by the Huanghai Warm Current （Yellow Sea Warm Current,HWC） accounted for up to 29% of the HS heat content change.Close correlation,especially in February,between the storm events and the SST increase demonstrates that the HWC behaves strongly as a wind-driven compensation current.
基金Supported by the National Natural Science Foundation of China(No.41230420)the Basic Research Program of Science and Technology Projects of Qingdao(No.11-1-4-95-jch)the Knowledge Innovation Program of Chinese Academy of Sciences(No.KZCX2-EW-201)
文摘Variations of sea surface height （SSH） in the Kuroshio south of Japan are addressed by analyzing 19-year （1993-2011） altimetry data from AVISO. Regionally averaged time series of observed SSH had a rising linear trend at 2.64＋0.72 mrn/a in this period. By analyzing the power spectra, several periods were recognized in temporal SSH variations, including those around 90 and 360 days. The seasonal cycle of SSH was minimum in winter （February） and maximum in summer （August）, with peak-to-peak amplitude about 20.0 cm. The spatial distribution of linear trends was inhomogeneous, with a rising linear trend along the coastline and a tripole structure offshore. Spatial distributions of standard deviation of seasonal SSH show very dynamic activities in the southeast of Kyushu and south of Honshu. Seasonal variations of observed SSH are partially explained by surface buoyancy forcing, local wind forcing and the steric component related to subsurface water beneath the mixed layer. Results show different spatial distributions of correlation coefficient and estimation skill between seasonally observed and modeled SSH, which are calculated from surface buoyancy flux, local wind forcing and the steric component related to subsurface water. Of those three, the surface buoyancy flux has a greater contribution to variations of observed SSH on the seasonal time scale south of Japan.
