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1.
A high-resolution downward surface solar radiation (DSSR) dataset has been produced using geostationary meteorological satellite measurements. Its validation with in situ observations shows that the daily satellite DSSRs are highly accurate. Comparing the satellite DSSRs with reanalysis DSSR datasets, the former has higher probability density in a low value range, and lower density in a high value range. Overestimations of the reanalysis DSSR are significant in the low range. Correlations between the reanalysis DSSRs and the satellite DSSR are relatively low in the tropics. It is suggested that the satellite DSSRs have good potential to capture cloud behavior in the tropics.  相似文献   

2.
Ultraviolet(UV) radiation has a significant influence on marine biological processes and primary productivity;however, the existing ocean color satellite sensors seldom contain UV bands. A look-up table of wavelengthintegrated UV irradiance(280–400 nm) on the sea surface is established using the coupled ocean atmosphere radiative transfer(COART) model. On the basis of the look-up table, the distributions of the UV irradiance at middle and low latitudes are inversed by using the satellite-derived atmospheric products from the Aqua satellite,including aerosol optical thickness at 550 nm, ozone content, liquid water path, and the total precipitable water.The validation results show that the mean relative difference of the 10 d rolling averaged UV irradiance between the satellite retrieval and field observations is 8.20% at the time of satellite passing and 13.95% for the daily dose of UV. The monthly-averaged UV irradiance and daily dose of UV retrieved by satellite data show a good correlation with the in situ data, with mean relative differences of 6.87% and 8.43%, respectively. The sensitivity analysis of satellite inputs is conducted. The liquid water path representing the condition of cloud has the highest effect on the retrieval of the UV irradiance, while ozone and aerosol have relatively lesser effect. The influence of the total precipitable water is not significant. On the basis of the satellite-derived UV irradiance on the sea surface, a preliminary simple estimation of ultraviolet radiation's effects on the global marine primary productivity is presented, and the results reveal that ultraviolet radiation has a non-negligible effect on the estimation of the marine primary productivity.  相似文献   

3.
A coastal atmosphere-ocean coupled system (CAOCS) is developed with Princeton Ocean Model (POM) as the oceanic component, and with National Center for Atmospheric Research (NCAR) regional climate model (RegCM2) as the atmospheric component. The model domain (98.84°–121.16°E, 3.06°S–25.07°N) covers the whole SCS and surrounding land and islands. The surface fluxes of water, heat (excluding solar radiation), and momentum are applied synchronously with opposite signs in the atmosphere and ocean. Flux adjustments are not used. The CAOCS model was verified using an intensive airborne expendable bathythermograph (AXBT) survey between 14–25 May 1995 over the majority of the SCS down to about 300-m depth.  相似文献   

4.
The accuracy of sea surface temperatures (SSTs) derived from the Advanced Very High Resolution Radiometer (AVHRR)/NOAA-11 is examined by comparison with sea-truth SSTs obtained from ocean data buoys durings November 1988 through December 1989. We made a 122 point data set of buoy SSTs from the oceans around Japan and the corresponding brightness temperatures of channels 4 and 5 during cloud free periods. The satellite temperatures are corrected for atmospheric effects using the NOAA Multi-Channel SST (MCSST) and Cross Product SST (CPSST) algorithms. The two algorithms give similar results for our data set and result in biases of about –0.1°C with rms errors of about 0.6°C relative to buoy SSTs. It is found that MCSSTs and CPSSTs tend to be higher than SSTs from the buoy in the Japan Sea in summer. New coefficients for the MCSST equations suitable for our data set are determined and the resultant rms error is 0.49°C. If we eliminate the cluster of anomalous summer data in the Japan Sea, the rms error becomes 0.43°C.  相似文献   

5.
Algorithms for obtaining operative information on the fluxes of the total solar radiation and radiation balance at the ocean surface are developed and realized on the basis of satellite observations within the spectral ranges 0·725–1·1 and 10·3–11·3 m at arbitrary scanning angles. For the 10-day and monthly values, the reconstruction errors remain at the level of the accuracy of the shipboard measurements. The atlas of charts of the above parameters (grid 0·5°×0·5°) is compiled using data obtained by the RVAkademik Vernadsky in the Atlantic Ocean during 1986–1989.Translated by Mikhail M. Trufanov.  相似文献   

6.
Within the framework of a correct model, by using long-term satellite information, we study the relations radiation–cloudiness, which are the most important characteristics of energy redistribution between the ocean and the atmosphere. They determine the spatial, seasonal, and interannual oscillations of solar and long-wave radiation in these media and stimulate circulation processes. The annual radiation regime of land and polar oceanic areas shows the present tendency towards global warming. On the average for a year, the radiation budget of the ocean–atmosphere system for the latitudinal zone between 63°N–63°S is stable towards significant variations of the conditions of cloudiness. In this region, the World Ocean acts as a factor stabilizing the global climate. The Earth represents a self-regulating system at the present stage of its evolution, and its climate varies slightly according to certain cycles.  相似文献   

7.
通过对西北太平洋最近九年爆发性气旋的分析表明:气旋的爆发性发展主要发生在冬半年的海洋上,集中在日本东南海域,且有明显的季节性。加深率以1.1贝吉龙居多。其发展过程的云形特征可归为四类:南北逗点云系迭加类;气旋锢囚性发展类;斜压叶状云系类和东西云系迭加类。  相似文献   

8.
We study the formation of the vertical distribution of temperature in the upper layer of the oceans (0– 300m) at low latitudes (10°N-10°S) by using the nonlinear dependence of the vertical heat flow on the vertical temperature gradient with regard for the influence of the bulk absorption of solar radiation and heat sink on the temperature of water. The thermocline is formed under the condition that the modulus of temperature gradient attains values for which their subsequent increase leads either to insignificant variations of the heat flow or even to its decrease. We consider the possibility of solution of inverse problems for the evaluation of the heat-exchange coefficient and the parameter of the heat sink. For the Equatorial Atlantic considered as an example, we compare the theoretical results with the data of instrumental measurements.__________Translated from Morskoi Gidrofizicheskii Zhurnal, No. 6, pp. 10–16, November–December, 2004.  相似文献   

9.
基于浮标实测数据的WindSat海洋反演产品精度分析   总被引:1,自引:1,他引:0  
To evaluate the ocean surface wind vector and the sea surface temperature obtained from Wind Sat, we compare these quantities over the time period from January 2004 to December 2013 with moored buoy measurements. The mean bias between the Wind Sat wind speed and the buoy wind speed is low for the low frequency wind speed product(WSPD_LF), ranging from –0.07 to 0.08 m/s in different selected areas. The overall RMS error is 0.98 m/s for WSPD_LF, ranging from 0.82 to 1.16 m/s in different selected regions. The wind speed retrieval result in the tropical Ocean is better than that of the coastal and offshore waters of the United States. In addition, the wind speed retrieval accuracy of WSPD_LF is better than that of the medium frequency wind speed product. The crosstalk analysis indicates that the Wind Sat wind speed retrieval contains some cross influences from the other geophysical parameters, such as sea surface temperature, water vapor and cloud liquid water. The mean bias between the Wind Sat wind direction and the buoy wind direction ranges from –0.46° to 1.19° in different selected regions. The overall RMS error is 19.59° when the wind speed is greater than 6 m/s. Measurements of the tropical ocean region have a better accuracy than those of the US west and east coasts. Very good agreement is obtained between sea surface temperatures of Wind Sat and buoy measurements in the tropical Pacific Ocean; the overall RMS error is only 0.36°C, and the retrieval accuracy of the low latitudes is better than that of the middle and high latitudes.  相似文献   

10.
A review of contemporary methods for determining integrated parameters of the water content in the atmosphere―atmospheric water-vapor content and cloud liquid-water content―is presented. Fields of these parameters can only be mapped spatially on the basis of using data of satellite measurements. The least errors of the retrieval of atmospheric water-vapor content and cloud liquid-water content is provided by methods based on using measurements of the satellite-borne scanning multichannel microwave radiometers over the ice-free ocean areas in the absence of precipitation. Most methods for retrieving the atmospheric water-vapor content and cloud liquid-water content from the data of microwave radiometers are based on results of numerical simulation of brightness temperatures of the upwelling microwave radiation of the ocean–atmosphere system. The evolution of satellite-borne microwave radiometers and methods for the retrieval of integrated parameters of water content is presented.  相似文献   

11.
自欧洲土壤湿度和盐度卫星SMOS和美国宝瓶座盐度卫星Aquarius相继发射之后,多个数据中心发布了两颗卫星的海表盐度网格化产品,其中包括法国海洋研究院SMOS卫星数据小组发布SMOS Locean L3盐度产品、西班牙巴塞罗那专家中心发布SMOS BEC L4盐度产品和美国宇航局喷气动力实验室发布AquariusV3.0 CAP L3盐度产品。本文利用精确盐度现场观测资料从产品精度和模拟海洋现象能力两个方面对以上3种产品质量进行了评估。研究表明:(1) 在精度方面,与盐度现场资料相比,Aquarius CAP 产品质量最高,产品盐度偏差和均方根误差全年稳定且偏差较小,部分海域达到了设计精度;SMOS两种卫星产品在全球海域偏差较不稳定,个别月份出现异常偏差值;SMOS产品在低纬和开阔海域的数据质量相对较高,但在高纬海域仍存在较大误差,需要进一步提升;(2) 在刻画海洋现象方面,Aquarius产品在热带太平洋较好刻画了淡池东缘盐度锋,SMOS BEC产品的刻画能力次之,SMOS Locean产品在热带太平洋充满了小尺度噪音,描述物理现象方面表现偏差。  相似文献   

12.
Remote sensing and surface POC concentration in the South Atlantic   总被引:1,自引:0,他引:1  
Several SeaWiFS products have been compared with shipboard data to assess the possibility of using remote sensing to estimate particulate organic carbon (POC) concentration in surface waters. Transmissometer data were collected during six South Atlantic Ventilation Experiment (SAVE) hydrographic expeditions conducted between November 1987 and March 1989 from R/V Knorr, and Melville. A total of 361 beam attenuation profiles were made with a SeaTech transmissometer interfaced with a CTD/rosette. In order to calculate the POC concentration from transmissometer profiles, a regression between beam attenuation and POC for open Atlantic Ocean waters derived from our research in the North Atlantic (North Atlantic Bloom Experiment, NABE) and enhanced by data from the Bermuda Atlantic Time Series Station (BATS) was applied. The profiles were processed and examined as vertical sections of the surface 250 m. The data were collected in two successive years, during the same season, which allowed us to compile a combined data set over the austral summer for examination. Beam attenuation/POC concentrations were integrated down to one attenuation depth with the intent of making comparisons with satellite optical data. No satellite optical data were available for 1987–1989, so the only option was to compare our integrated data with SeaWiFS-derived variables from later years averaged over the same season as SAVE data. Analysis of four SeaWiFS products acquired from 1997 to 2002 demonstrated very low variations from year to year for seasonally averaged data, suggesting that making comparisons of the beam attenuation/POC fields with averaged satellite optical products from later years is a valid (though not optimal) approach for this area. The highest correlation between beam attenuation/POC concentration and remotely derived products was found with normalized water-leaving radiance at 555 nm. Other SeaWiFS-derived variables—chlorophyll concentration, diffuse attenuation coefficient at 490 nm and integral chlorophyll (integrated over one attenuation depth)—were also compared but showed a slightly less satisfactory correlation.  相似文献   

13.
A pair of buoys (system), MET and OPTICAL, consisting of fully automated hyperspectral radiometers, fluorometer, and meteorological sensors, has been realized and deployed in deep ocean case-I site at Kavaratti in Lakshadweep, Arabian Sea, for preprogrammed in situ data collection and transmission via INSAT-3C satellite. The buoy of described configuration is capable of measuring in-water optical and biological parameters in an unattended manner for long-term time series with less vertical tilt. A robotic sun/sky photometer installed on Kavaratti Island simultaneously provides information on aerosols over the site. A combination of these parameters available hourly in real time throughout the day from unattended systems in the ocean as well as on island provides an ideal reference site. The paper reports recent collection of bio-optical marine observations over the site and use of the data for OCM-2 vicarious calibration and validation of geophysical products.  相似文献   

14.
The structure of the field of outgoing into space radiation for the 8–12 m spectral interval is studied using the data of satellite observations of the oceans. The regularity found is employed to substantiate the angular method for the sea surface temperature (SST) reconstruction. The band of the angles of view is determined in which the error of the SST reconstructon does not exceed 0.3°C with the assigned error of the satellite measurements of radiation temperatures of 0.05°C.UDK 551.507.362.2Translated by Mikhail M. Trufanov.  相似文献   

15.
Evaporation and vertical moisture and heat transfer from the underlying surface are the basis of cloud formation. The situation when the coming relatively cold stably stratified air moves over a warm ocean is a typical problem in the development of a turbulent convective layer. The problem of cloud formation is also of scientific and practical interest. This paper considers the problems of the formation of a turbulent convective layer over a warmer ocean and the vertical distribution of relative humidity. The results of the theoretical model are compared with the data of observations of the development of the turbulent convective layer at low latitudes (in the Indian Ocean) and at higher latitudes (in autumn over Lake Michigan). Approximate equations describe well the dynamics of temperature and humidity of the layer as a function of the difference between the temperatures of the approaching and near-surface air layers. The theoretical results are compared with the data on measurements of the condensation heights obtained at the Novosibirsk Tolmachevo Airport. Some discrepancy between them is due to the unsteadiness measurement and the approximations adopted in the theoretical model.  相似文献   

16.
This study quantifies uncertainties in closing the seasonal cycle of diabatic heat storage (DHS) over the Pacific Ocean from 20°S to 60°N through the synthesis of World Ocean Circulation Experiment (WOCE) reanalysis products from 1993 to 1999. These products are DHS from Scripps Institution of Oceanography (SIO); near-surface geostrophic and Ekman currents from Earth and Space Research (ESR); and air-sea heat fluxes from Comprehensive Ocean-Atmosphere Data Set (COADS), National Centers for Environmental Prediction (NCEP), and European Center for Mid-Range Weather Forecasts (ECMWF). With these products, we compute residual heat budget components by differencing long-term monthly means from the long-term annual mean. This allows the seasonal cycle of the DHS tendency to be modeled. Everywhere latent heat flux residuals dominate sensible heat flux residuals, shortwave heat flux residuals dominate longwave heat flux residuals, and residual Ekman heat advection dominates residual geostrophic heat advection, with residual dissipation significant only in the Kuroshio-Oyashio current extension. The root-mean-square (RMS) of the differences between observed and model residual DHS tendencies (averaged over 10° latitude-by-20° longitude boxes) is <20 W m−2 in the interior ocean and <100 W m−2 in the Kuroshio-Oyashio current extension. This reveals that the residual DHS tendency is driven everywhere by some mix of residual latent heat flux, shortwave heat flux, and Ekman heat advection. Suppressing bias errors in residual air-sea turbulent heat fluxes and Ekman heat advection through minimization of the RMS differences reduces the latter to <10 W m−2 over the interior ocean and <25 W m−2 in the Kuroshio-Oyashio current extension. This reveals air-sea temperature and specific humidity differences from in situ surface marine weather observations to be a principal source of bias error, overestimated over most of ocean but underestimated near the Intertropical Convergence Zone.  相似文献   

17.
Using the air-sea data set of January, 1983 (the mature phase of the 1982/83 El Nino event), the net radiation on the sea surface, the fluxes of the latent and the sensible heat from ocean to the atmosphere and the net heat gain of the sea surface are calculated over the Indian and the Pacific Oceans for the domain of 35°N-35°S and 45°E-75°W. The results indicate that the upward transfer of the latent and the sensible heat fluxes over the winter hemisphere is larger than that over the summer hemisphere. The sensible heat over the tropical mid Pacific in the Southern Hemisphere is transported from the atmosphere to the ocean, though its magnitude is rather small. The latent heat flux gained by the air over the eastern Pacific is less than the mean value of the normal year. The net radiation, on which the cloud amount has considerable impact, is essentially zonally distributed. Moreover, the sea surface temperature (SST) has a very good correlation with the net radiation, the region of warm SST coinci  相似文献   

18.
Atmospheric CO_2 is one of key parameters to estimate air-sea CO_2 flux. The Orbiting Carbon Observatory-2(OCO-2) satellite has observed the column-averaged dry-air mole fractions of global atmospheric carbon dioxide(XCO_2)since 2014. In this study, the OCO-2 XCO_2 products were compared between in-situ data from the Total Carbon Column Network(TCCON) and Global Monitoring Division(GMD), and modeling data from CarbonTracker2019 over global ocean and land. Results showed that the OCO-2 XCO_2 data are consistent with the TCCON and GMD in situ XCO_2 data, with mean absolute biases of 0.25×10-6 and 0.67×10-6, respectively. Moreover, the OCO-2 XCO_2 data are also consistent with the CarbonTracker2019 modeling XCO_2 data, with mean absolute biases of 0.78×10-6 over ocean and 1.02×10-6 over land. The results indicated the high accuracy of the OCO-2 XCO_2 product over global ocean which could be applied to estimate the air-sea CO_2 flux.  相似文献   

19.
The first Chinese microwave ocean environment satellite HY-2A, carrying a Ku-band scatteromenter (SCAT), was successfully launched in August 2011. The first quality assessment of HY-2A SCAT wind products is presented through the comparison of the first 6 months operationally released SCAT products with in situ data. The in situ winds from the National Data Buoy Center (NDBC) buoys, R/V Polarstern, Aurora Australis, Roger Revelle and PY30-1 oil platform, were converted to the 10 m equivalent neutral winds. The temporal and spatial differences between the HY-2A SCAT and the in situ observations were limited to less than 5 min and 12.5 km. For HY-2A SCAT wind speed products, the comparison and analysis using the NDBC buoys yield a bias of-0.49 m/s, a root mean square error (RMSE) of 1.3 m/s and an increase negative bias with increasing wind speed observation above 3 m/s. Although less accurate of HY-2A SCAT wind direction at low winds, the RMSE of 19.19° with a bias of 0.92° is found for wind speeds higher than 3 m/s. These results are found consistent with those from R/Vs and oil platform comparisons. Moreover, the NDBC buoy comparison results also suggest that the accuracy of HY-2A SCAT winds is consistent over the first half year of 2012. The encouraging assessment results over the first 6 months show that wind products from HY-2A SCAT will be useful for scientific community.  相似文献   

20.
卫星重力估计陆地水和冰川对全球海平面变化的贡献   总被引:2,自引:0,他引:2  
重力场恢复与气候试验(GRACE)卫星为高分辨率地监测全球海洋质量变化提供了一种新的手段。利用2003年1月至2014年12月Level-2 RL05的GRACE产品,进行去相关误差滤波、高斯滤波和海洋-陆地信号泄漏改正后,得到了全球陆地和海水质量变化,并分析了陆地水和冰川的质量变化对海平面长期变化的贡献。研究表明,全球陆地水和冰川的质量变化对海平面的贡献约为(2.09±0.54)mm/a,与卫星测高扣除海洋温盐数据比热容变化得到的海水质量长期变化(2.07±0.62)mm/a有着很好的一致性,其中全球陆地水储量对全球质量项海平面变化的贡献为(0.15±0.25)mm/a,南极冰盖对全球质量项海平面变化的贡献为(0.59±0.10)mm/a,格陵兰岛冰盖对全球质量项海平面变化的贡献为(0.72±0.12)mm/a,山地冰川对全球质量项海平面变化的贡献为(0.63±0.09)mm/a。并进一步讨论了不同分析中心GRACE重力场系数,一阶项系数和二阶项对质量项海平面变化的影响。结果表明,一阶项对质量项海平面的影响为(0.10±0.08)mm/a,二阶项对质量项海平面的影响为(0.16±0.04)mm/a,美国德克萨斯大学空间研究中心和德国地学研究中心分析结果较为一致,而美国国家航空航天局喷气推进实验室的结果则稍稍偏小。  相似文献   

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