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1.
The Infrared Atmospheric Sounding Interferometer (IASI) is a new-generation ultraspectral atmospheric sounding instrument mounted on the MetOp-A, the first operational polar-orbiting satellite developed by the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT). It is an ultrahigh spectral-resolution atmospheric detector which can detect atmospheric chemical composition, temperature, and humidity profiles with high accuracy and resolution. In the present study, through comparative analyses of the similarities and differences between the IASI and the radiosonde observation (RAOB) water vapor data, and between the IASI and the Aqua-AIRS water vapor retrievals, a detailed and systematic assessment of the credibility of the IASI water vapor retrievals over the plateau region was made. A comparison of the IASI retrievals with the AIRS retrievals and the RAOB measurements over the Tibetan Plateau revealed that the IASI retrieval data are reliable and can be used for conducting further studies.  相似文献   

2.
Monitoring atmospheric carbon dioxide(CO_2) from space-borne state-of-the-art hyperspectral instruments can provide a high precision global dataset to improve carbon flux estimation and reduce the uncertainty of climate projection. Here, we introduce a carbon flux inversion system for estimating carbon flux with satellite measurements under the support of "The Strategic Priority Research Program of the Chinese Academy of Sciences—Climate Change: Carbon Budget and Relevant Issues". The carbon flux inversion system is composed of two separate parts: the Institute of Atmospheric Physics Carbon Dioxide Retrieval Algorithm for Satellite Remote Sensing(IAPCAS), and Carbon Tracker-China(CT-China), developed at the Chinese Academy of Sciences. The Greenhouse gases Observing SATellite(GOSAT) measurements are used in the carbon flux inversion experiment. To improve the quality of the IAPCAS-GOSAT retrieval, we have developed a post-screening and bias correction method, resulting in 25%–30% of the data remaining after quality control. Based on these data, the seasonal variation of XCO_2(column-averaged CO_2dry-air mole fraction) is studied, and a strong relation with vegetation cover and population is identified. Then, the IAPCAS-GOSAT XCO_2 product is used in carbon flux estimation by CT-China. The net ecosystem CO_2 exchange is-0.34 Pg C yr~(-1)(±0.08 Pg C yr~(-1)), with a large error reduction of 84%, which is a significant improvement on the error reduction when compared with in situ-only inversion.  相似文献   

3.
An ocean biogeochemistry model was developed and incorporated into a global ocean general circulation model (LICOM) to form an ocean biogeochemistry general circulation model (OBGCM). The model was used to study the natural carbon cycle and the uptake and storage of anthropogenic CO2 in the ocean. A global export production of 12.5 Pg C yr-1 was obtained. The model estimated that in the pre-industrial era the global equatorial region within 15o of the equator released 0.97 Pg C yr-1 to the atmosphere, which was balanced by the gain of CO2 in other regions. The post-industrial air-sea CO2 flux indicated the oceanic uptake of CO2 emitted by human activities. An increase of 20－50 mol kg-1 for surface dissolved inorganic carbon (DIC) concentrations in the 1990s relative to pre-industrial times was obtained in the simulation, which was consistent with data-based estimates. The model generated a total anthropogenic carbon inventory of 105 Pg C as of 1994, which was within the range of estimates by other researchers. Various transports of both natural and anthropogenic DIC as well as labile dissolved organic carbon (LDOC) were estimated from the simulation. It was realized that the Southern Ocean and the high-latitude region of the North Pacific are important export regions where accumulative air-sea CO2 fluxes are larger than the DIC inventory, whereas the subtropical regions are acceptance regions. The interhemispheric transport of total natural carbon (DIC+LDOC) was found to be northward (0.11 Pg C yr-1), which was just balanced by the gain of carbon from the atmosphere in the Southern Hemisphere.  相似文献   

4.
张磊  董超华  张文建  张鹏 《气象科技》2008,36(5):639-642
为了深入了解国际卫星红外大气探测仪器的新特点,以欧洲METOP卫星装载的超高光谱红外大气探测仪(IASI:Infrared Atmospheric Sounding Interferometer)为例,介绍卫星红外探测仪研发背景、仪器特征和数据产品处理,并与第1个高光谱大气红外探测仪(AIRS:Atmosphenic Inftared Sounder)作了比较分析.采用干涉分光技术的IASI为地球大气遥感提供了丰富的研究资料,可用于反演大气、海洋、云和大气成分,对我国风云卫星的高光谱红外大气垂直探测仪器的研发具有重要参考价值.  相似文献   

5.
西藏当雄地基紫外线指数观测研究   总被引：1，自引：1，他引：0       下载免费PDF全文
基于西藏当雄2009年9月—2011年8月地基紫外线指数 (UVI) 观测,结合TUV辐射传输模式分析, 该文检验太阳天顶角、云、臭氧、积雪和气溶胶对UVI的影响。结果显示,影响地面UVI主要因素是太阳天顶角和云。晴天地面UVI可简单用太阳天顶角拟合函数表征;地面UVI的云调制因子总体上随云量增加呈下降趋势,但间隙性、未遮蔽日面的云可增强太阳散射辐射,使云调制因子值平均增加约3%~6%,个别情形达40%。臭氧低谷使当雄UVI比同纬度平原地区增加约12%;冬季短期、浅层积雪使UVI增加16%或更低,也低于模式模拟值 (23%);气溶胶 (光学厚度为0.02~0.1) 对UVI衰减低于3%。因臭氧低谷导致青藏高原臭氧南北分布的差异,相同太阳天顶角下拉萨 (海拔为3650 m) UVI较瓦里关 (海拔为3810 m) 偏高7%~10%。与卫星产品比较表明:OMI卫星UVI产品在当雄、沱沱河、瓦里关和拉萨较地基测值总体偏高65%以上,而晴天则平均分别偏高8.6%,13%,9%和50%。云、地基与卫星像元地理位置差异应是卫星UVI产品偏高的原因。当雄地基UVI测值大于14时,卫星UVI产品反而低3%应与间隙性云有效增强了地面辐射有关。  相似文献   

6.
本文基于北京325米气象塔在47,140,和280米三层高度的5年涡动相关观测资料,研究了城市下垫面与大气间的CO2交换过程.由于北京市2011年开始实行工作日汽车尾号限行,140米高度CO2通量的年增长率由2008-2010年的7.8％降低到2010-2012年的2.3％.140米高度通量源区内植被比例最小且人口密度最大,因此140米高度的5年平均CO2通量年总量)6.41 kg C m-2 yr-1(大于47米)5.78 kg C m-2 yr-1(和280米)3.99 kg C m-2 yr-1(.在年尺度上,北京汽车总保有量和总人口是最重要的CO2通量控制因子.CO2通量随风向的变化主要与风向对应的通量源区内下垫面土地利用方式有关.三层高度的夏季CO2通量均与道路的比例呈正相关关系.47,140,和280米的决定系数分别为0.69,0.57,和0.54(P＜0.05).植被比例的下降,会导致CO2年总量上升,两者存在近似于指数的关系.城市人口密度的上升会引起CO2年总量上升.  相似文献   

7.
云对中国区域卫星观测臭氧总量精度影响的检验分析   总被引：5，自引：0，他引：5  
郑向东 《大气科学》2008,32(6):1431-1444
根据卫星和地基观测, 比较了我国香河、 昆明、 瓦里关和龙凤山四个站点臭氧总量自1979年以来的变化。卫星与地基观测的臭氧总量长期趋势比较一致, 表明臭氧总量均有下降趋势, 但是卫星与地基各自观测的结果仍存在着显著的差别。为研究卫星与地基臭氧总量的差别, 以地基观测臭氧总量为参考, 检验云对历史TOMS (Total Ozone Mapping Spectrometer) 和GOME (Global Ozone Monitoring Experiment) 臭氧总量精度的影响。结果显示: 云 (云量或云顶高度) 增加了卫星臭氧总量误差, 降低数据精度。随着地面云量的增加, TOMS、 GOME臭氧总量相对误差在上述四个地点呈现明显的上升趋势 (瓦里关最为明显), 但最大变化幅度没有超过2.0%。TOMS臭氧总量相对误差随地面云量变化呈现区域性特点, 香河与龙凤山 (代表着中纬度高臭氧总量区域)、 昆明与瓦里关 (代表中、 低纬度高原低臭氧总量区域) 分别为两个变化特点接近的区域。GOME臭氧总量相对误差与云之间关系的区域特征不明显。利用卫星遥测FRESCO (Fast Retrieval Scheme for Clouds from the Oxygen A\|band) 云信息检验GOME卫星臭氧总量精度的表明, 只有当云量大于5成后GOME臭氧总量才显示出相对误差增加的现象, 但无明显趋势; 随着FRESCO云顶高度的增加, GOME臭氧相对误差在香河、 瓦里关均呈现明显的上升趋势并有3%左右幅度的变化。TOMS臭氧总量相对误差随着地面有效反射率的增加而增大, 且误差幅度超过2%; TOMS\|N7臭氧总量比TOMS\|EP约高2.0%~3.0%。分析还表明, 云内和云以下臭氧柱浓度在反演的卫星臭氧总量中的贡献很可能被高估了。  相似文献   

8.
In an effort to assess the impact of the individual component of meteorological observations (ground-based GPS precipitable water vapor,automatic and conventional meteorological observations) on the torrential rain event in 4-5 July 2000 in Beijing (with the 24-h accumulated precipitation reaching 240 mm),24-h observation system experiments are conducted numerically by using the MM5/WRF 3DVAR system and the nonhydrostatic MM5 model.Results indicate that,because the non-conventional GPS observations are directly assimilated into the initial analyses by 3DVAR system,better initial fields and 24-h simulation for the severe precipitation event are achieved than those under the MM5/Litter_R objective analysis scheme. Further analysis also shows that the individual component of meteorological observation network plays their special positive role in the improvement of initial field analysis and forecasting skills.3DVAR scheme with or without radiosonde and pilot observation has the most significant influence on numerical simulation,and automatic and conventional surface meteorological observations rank second.After acquiring the supplement information from the other meteorological observations,the ground-based GPS precipitable water vapor data can more obviously reflect initial field assimilation and precipitation forecast.By incorporating the ground- based GPS precipitable water vapor data into the 3DVAR analyses at the initial time,the threat scores (TS) with thresholds of 1,5,10,and 20 mm are increased by 1%-8% for 6- and 24-h accumulated precipitation observations,respectively.This work gives one helpful example that assesses the impact of individual component of the existing meteorological observation network on the high influence weather event using 3DVAR numerical system.  相似文献   

9.
The satellite-derived wind from cloud and moisture features of geostationary satellites is an important data source for numerical weather prediction(NWP) models. These datasets and global positioning system radio occultation(GPSRO)satellite radiances are assimilated in the four-dimensional variational atmospheric data assimilation system of the UKMO Unified Model in India. This study focuses on the importance of these data in the NWP system and their impact on short-term24-h forecasts. The quality of the wind observations is compared to the short-range forecast from the model background. The observation increments(observation minus background) are computed as the satellite-derived wind minus the model forecast with a 6-h lead time. The results show the model background has a large easterly wind component compared to satellite observations. The importance of each observation in the analysis is studied using an adjoint-based forecast sensitivity to observation method. The results show that at least around 50% of all types of satellite observations are beneficial. In terms of individual contribution, METEOSAT-7 shows a higher percentage of impact(nearly 50%), as compared to GEOS, MTSAT-2and METEOSAT-10, all of which have a less than 25% impact. In addition, the impact of GPSRO, infrared atmospheric sounding interferometer(IASI) and atmospheric infrared sounder(AIRS) data is calculated. The GPSRO observations have beneficial impacts up to 50 km. Over the Southern Hemisphere, the high spectral radiances from IASI and AIRS show a greater impact than over the Northern Hemisphere. The results in this study can be used for further improvements in the use of new and existing satellite observations.  相似文献   

10.
A modern three-dimensional chemistry transport model is adopted for computation of air pollution with photo-oxidants in the Moscow megalopolis and in the several neighboring regions. Along the vertical, the model covers the entire troposphere and has a two-scale horizontal structure, when the resolution of the “inserted” domain is about 13 km. The model computation results are compared with the satellite tropospheric nitrogen dioxide measurements and ground-based measurements of the surface ozone concentration. The analysis results of one of the episodes of enhanced ozone content is considered as an example of a possible use of the model considered as a diagnostic tool for studying issues connected with the air pollution in the region under consideration.  相似文献   

11.
Soil respiration is a key component of the global terrestrial ecosystem carbon cycle. The static opaque chamber method was used to measure the CO2 effluxes from soil of a semiarid Aneurolepidium chinense steppe and a Stipa krylovii steppe in the Xilin River Basin of Inner Mongolia, China from March 2002 to December 2004. The results indicated that the soil respiration rates of the semiarid Aneurolepidium chinense steppe and the Stipa krylovii steppe were both relatively high from mid-May to mid-September of each year and remained low during the rest of the year. The minimum value of soil respiration occurred in December or January and negative effluxes of CO2 appeared for several days during the non-growing season of individual years at the two sampling sites. A high annual variation was found in the two steppes with the coefficients of variance (CV) being over 94%, even high to 131%. The annual sums of soil CO2 efflux of the Aneurolepidium chinense steppe varied between 356.4 gC m?2 yr?1 and 408.8 gC m?2 yr?1, while those of the Stipa krylovii steppe in the three years were in the range of 110.6 gC m?2 yr?1 to 148.6 gC m?2 yr?1. The mean respiration rates of the Aneurolepidium chinense steppe were significantly higher than those of the Stipa krylovii steppe in different statistical periods with the exception of the non-growing season. About 59.9% and 80.6% of the soil respiration variations in both steppes for the whole sampling period were caused by the changes of temperature and soil water content. In the Aneurolepidium chinense steppe, the soil respiration rate has significant or extremely significant positive correlation (r = 0.58 ? 0.85, p < 0.05 or p < 0.01) with air temperature and ground temperature of the topsoil except in 2002; the unique contributions of temperature change to the soil respiration variation of the three years were 53.3%, 81.0% and 58.6%, respectively. But, for the Stipa krylovii steppe in the same time interval, the soil water content (especially that of the 10–20 cm layer) has a greater effect on the change of soil respiration, and the unique contributions of the change of the 10–20 cm soil water content to the variations of soil respiration in 2002 and 2003 were 60.0% and 54.3%, respectively. In 2004, in spite of the higher contribution of temperature than soil water content, the contribution of ground temperature at a depth of 10 cm was only 46.2%, much weaker than that of any single year in the Aneurolepidium chinense steppe.  相似文献   

12.
Carbon dioxide, methane, and carbon monoxide are the carbon cycle gases, the data on their emissions are needed when monitoring air pollution and developing methods for reducing anthropogenic emissions to the atmosphere and for climate forecasting. The estimates of nocturnal area fluxes for CO2, CH4, and CO presented for a suburb of Saint Petersburg (Peterhof) are obtained using the box model and continuous observations of concentration of these gases. The mean values of CH4, CO2, and CO fluxes estimated for Peterhof for 2014–2015 are 44 ± 27, 6100 ± 4000, and 90 ± 100 t/(km2 year), respectively. The intensity of the CO area flux has pronounced seasonal variations characterized by the maximum of ~(160 ± 120) t/(km2 year) in November—February and by the minimum of ~(30 ± 20) t/(km2 year) in June-July. The analysis of the ratio of CO/CO2 fluxes identified the main types of anthropogenic sources typical of Peterhof: motor transport, natural gas combustion, and the use of wood stoves for the heating of private low-rise buildings (in the cold season).  相似文献   

13.
IASI（Infrared Atmospheric Sounding Interferometer）是搭载在欧洲METOP-A 卫星上,采用干涉分光技术的新一代超高光谱红外大气探测仪器,其光谱测量范围涵盖了多个吸收带,可用于反演大气、海洋、云和大气成分,为地球大气遥感、气象业务和科学研究提供了丰富的遥感资料,是各国学者关注的又一热点。为深入了解IASI 在国内的云产品情况,本文利用2008 年10 月15 日～12 月15 日期间IASI 在安徽寿县地区的云参数观测资料和中美 [美国能源部大气辐射测量（ARM）计划] 联合在安徽省寿县进行大气辐射综合观测试验期间,相同时段云雷达[ARM W-band（95 GHz）Cloud Radar,WACR]的观测资料进行了对比分析和验证。在以寿县ARM 移动观测设施（AMF）为中心,半径为20 km 的范围内,IASI（2 次/d）共有有效观测129 次,其中与WACR（1 次/2 s）匹配的IASI 有效观测共80 时次。结果表明:对于单层云,二者云高相关系数为0.8312,标准差为1.8423 km;对于双层及多层云,IASI 反演云顶高结果绝大多数在WACR 的最上和最下层云之间,且靠近较厚的云层。对比结果显示,一般情况下,IASI 反演云顶高结果明显低于WACR;IASI 反演云顶高结果受到视场中云量、云层厚度及云层中粒子浓度大小的影响:视场中云量越大,云层越厚,云层中粒子浓度越大,IASI 反演云高的结果越接近真实云高。  相似文献   

14.
中国4个地点地基与卫星臭氧总量长期观测比较   总被引：1，自引：0，他引：1       下载免费PDF全文
对我国河北香河、云南昆明、青海瓦里关及黑龙江龙凤山地基观测臭氧总量与不同时期、不同卫星反演的产品差别特点进行比较,评估地基和卫星观测臭氧总量数据的质量信息以及近30年来我国不同区域臭氧总量的变化趋势特征。结果表明:4个站点的地基与卫星观测臭氧总量的绝对和相对差别分别为-5~10 DU和-5%~4%;日平均相对差别基本上呈现随机分布特征。TOMS算法反演的卫星臭氧总量与地基差别总体上要优于与DOAS算法反演的同期产品。地基与卫星臭氧总量差别呈明显的区域特点,可能反映了卫星反演计算中所需的臭氧、温度垂直分布等初始条件的纬度分布差异对卫星产品精度的影响。在过去30年,4个站点的臭氧总量在经历1993年前的显著降低后于1995—1996年逐渐回升,而瓦里关站在2001年前后的回升更为明显。  相似文献   

15.
极轨卫星的高级微波温度计(Advanced Microwave Sounding Unit-A,简称AMSU-A)辐射资料对提高降水定量预报的水平有重要作用.但是极轨卫星的轨道特征导致乘载其上的微波温度计资料在区域同化系统中存在严重缺测.本研究重点分析了晨昏轨道卫星上微波温度计资料同化对墨西哥湾沿岸定量降水预报的重要影响.研究选取了早晨星NOAA-15、上午星MetOp-A和下午星NOAA-18,利用美国NCEP(National Centers for Environmental Prediction)的业务同化系GSI(Gridpoint Statistical Interpolation)资料同化系统,进行了加和不加NOAA-15 AMSU-A资料的两组资料同化和预报试验,来阐明晨昏轨道卫星上微波温度计资料同化对墨西哥湾沿岸降水预报的重要影响.试验结果分析表明如果仅同化NOAA-18和MetOp-A资料,在协调世界时00:00和12:00的同化时间,在墨西哥湾和美国西部大陆就是卫星观测资料缺测区,而早晨星NOAA-15资料正好可以填补这个资料空缺.模式预报也表明,同化NOAA-15的AMSU-A资料可以对墨西哥湾降水有持续的正影响.这一研究证明了保持有搭载着AMSU-A或者相似仪器的早晨星,对区域降水预报的重要性.由于目前NOAA-15是唯一的一颗正在运行的、已远超过其正常运行期的早晨星,通过技术手段维持NOAA-15的AMSU-A仪器更超长期运行也就特别重要.  相似文献   

16.
This article reviews recent advances over the past 4 years in the study of the carbon-nitrogen cycling and their relationship to climate change in China. The net carbon sink in the Chinese terrestrial ecosystem was 0.19-0.26 Pg C yr-1 for the 1980s and 1990s. Both natural wetlands and the rice-paddy regions emitted 1.76 Tg and 6.62 Tg of CH 4 per year for the periods 1995-2004 and 2005-2009, respectively. China emitted～1.1 Tg N 2 O-N yr-1 to the atmosphere in 2004. Land soil contained～8.3 Pg N. The excess nitrogen stored in farmland of the Yangtze River basin reached 1.51 Tg N and 2.67 Tg N in 1980 and 1990, respectively. The outer Yangtze Estuary served as a moderate or significant sink of atmospheric CO 2 except in autumn. Phytoplankton could take up carbon at a rate of 6.4 ×10 11 kg yr-1 in the China Sea. The global ocean absorbed anthropogenic CO 2 at the rates of 1.64 and 1.73 Pg C yr-1 for two simulations in the 1990s. Land net ecosystem production in China would increase until the mid-21st century then would decrease gradually under future climate change scenarios. This research should be strengthened in the future, including collection of more observation data, measurement of the soil organic carbon (SOC) loss and sequestration, evaluation of changes in SOC in deep soil layers, and the impacts of grassland management, carbon-nitrogen coupled effects, and development and improvement of various component models and of the coupled carbon cycle-climate model.  相似文献   

17.
利用行业经济活动数据、1 580个地面监测站和6套卫星反演数据,分析了我国新冠肺炎疫情期间人为碳排放和主要大气污染物的变化。与2019年第一季度相比,2020年同期我国碳排放降低9.8%,其中交通部门降幅最大达到43.4%。与2019年2-3月相比,疫情期间全国地表臭氧浓度同比升高1.9 nL/L(5%),其中华北平原以降低为主,东南部地区以上升为主。PM2.5浓度同比下降12.6μg·m^-3(24.9%),其中长三角降幅最大。二氧化氮(NO2)的地面浓度和对流层柱浓度在京津冀、珠三角和长三角都降低20%~30%,体现了高低层的一致性。地面一氧化碳(CO)浓度同比降低17%,而对流层CO柱浓度升高2.5%,可能原因是境外生物质燃烧输送提升了我国南方高层大气的CO浓度。中东部地区气溶胶光学厚度显著降低,导致地表晴空短波辐射同比升高11.6 W·m^-2(9.6%)。  相似文献   

18.
1 INTRODUCTION The Tropical Cyclone (TC) moving prediction is always difficult and important in operation. Though the numerical prediction and satellite data have contributed to the promotion of prediction capability in this way[1 – 3], it is not as satisfying for the unusual track of TC, and the primary reason is that the TC moving direction is influenced by many complicated factors. Therefore, further study of unusual TC motion using high-resolution satellite data is very important …  相似文献   

19.
The possibility is considered ofusing calculated and satellite data in addition to the results of direct actinometric observations in order to maintain the series of Earth surface radiation budget and to study its spatial variability. The empirical relationships are obtained based on the regression analysis of atmospheric radiation and meteorological parameters using the data of long-term observations in Lomonosov Moscow State University Meteorological Observatory (MSU MO). Satellite data needed to compute the Earth surface radiation budget are compared with the respective data of ground-based observations in MSU MO, and the possibility of using them is assessed.  相似文献   

20.
2000年后全球气温的增温率显著下降,全球进入变暖减缓期.本文基于CRU(Climatic Research Unit) 观测资料,分析讨论了2000年后全球及欧亚中高纬度地区全球变暖的减缓特征,评估了CMIP5(Coupled Model Intercomparison Project Phase 5)试验多模式对全球变暖减缓的模拟及未来气温变化预估.结果表明,2000年后全球陆地平均地面气温的增温率大幅下降至0.14℃ (10 a)-1,仅为1976~1999年加速期增温率的一半.全球陆地13个区域中有9个地区的增温率小于2000年前,4个地区甚至出现了降温.其中以欧亚中高纬地区最为特殊.加速期(1976~1999年)增温率达到0.50℃ (10 a)-1,为全球陆地最大,2000年后陡降至-0.17℃ (10 a)-1,为全球最强降温区,为全球变暖的减缓贡献了49.13%.并且具有显著的季节依赖,减缓期冬季增温率下降了-2.68℃ (10 a)-1,而秋季升高了0.86℃ (10 a)-1,呈现反位相变化特征.CMIP5多模式计划中仅BCC-CSM1.1在RCP2.6情景下和MRI-ESM1模式在RCP8.5下的模拟较好地预估了全球及欧亚中高纬地区在2000年后增温率的下降以及欧亚中高纬秋、冬温度的反位相变化特征.BCC-CSM1.1在RCP2.6情景下预估欧亚中高纬地区2012年后温度距平保持在1.2℃左右,2020年后跃至2℃附近振荡.而MRI-ESM1在RCP8.5情景下预估的欧亚中高纬度温度在2030年前一直维持几乎为零的增温率,之后迅速升高.  相似文献   

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