高分五号大气痕量气体差分吸收光谱仪甲醛反演可行性分析及初步结果     

王雅鹏  陶金花  程良晓  余超  范萌  张莹  陈元琳  朱莉莉  顾坚斌  陈良富 《遥感学报》2021,25(10):2040-2052

大气痕量气体差分吸收光谱仪EMI（ Environmental trace gases Monitoring Instrument）是搭载在“高分五号”（GF-5）卫星上的覆盖紫外—可见光波段的光谱仪,用于测量240—710 nm波长范围内的地球后向散射和太阳辐射,旨在量化全球对流层和平流层痕量气体的分布,如臭氧、二氧化氮等。本文关注EMI载荷对大气弱痕量气体甲醛（HCHO）的探测能力,并基于实测数据初步评估EMI HCHO产品的探测能力与精度。研究结果表明EMI的辐照度波长校准精度高,但在不同行之间存在较大的不均匀性,其波长校正的精度与仪器的狭缝函数高度依赖行位置的变化。基于EMI的HCHO反演的结果表明,EMI UV2频段的标称信噪比较低,使得利用差分吸收光谱技术（DOAS）得到的HCHO斜柱浓度SCD（Slant Column Density）存在较大的随机误差和拟合残差。现阶段,评估得到的EMI HCHO斜柱浓度的不确定性为1.2×10¹⁶ molec./cm²。与国际同类载荷TROPOMI（TROPospheric Ozone Monitoring Instrument）、OMI（Ozone Monitoring Instrument）的交叉对比验证结果表明,EMI可以捕捉到中国地区夏季HCHO的空间分布特征。EMI & TROPOMI与EMI & OMI的相关系数均大于0.8。但是在华东地区EMI HCHO普遍高于OMI和TROPOMI,其原因需要进一步研究。本文的研究证明了EMI对夏季HCHO的探测潜力及不足,可为后续类似载荷的指标设计和算法研发提供参考。  相似文献   

AIS船舶污染风险定量评估模型     

柴田  熊德琪 《测绘科学》2013,38(3):137-139

针对目前海上船舶污染风险评估模型的不足,本文提出一种基于船舶自动识别系统(AIS)的海上船舶污染风险定量评估数学模型。该模型的特点是对特定海域船舶污染历史事故进行统计分析,通过AIS中的信息对船舶事故频率进行建模及数值计算;并且模型考虑到事故海域资源类型,船舶种类、大小、风险程度以及污染事故等级等因素,使污染风险评估更科学化和定量化。  相似文献   

利用ArcGIS转换HPD源数据库中航海物标空间数据   总被引：2，自引：0，他引：2  

李颖  徐进  李家  张安民  卫国兵  杨龙 《测绘科学》2013,38(5):141-142,145

我国海事测绘部门自2008年开始引进CARIS HPD海道产品数据库系统,其空间数据共享转换方法一直是无法解决的难题。本文从CARIS HPD物标源数据库和Shapefile文件数据存储结构入手,详细阐述了CARIS HPD航海物标源数据空间信息获取方法和ArcGIS Shapefile文件生成方式,并提出将物标空间数据从HPD源数据库转换至Shapefile文件的解决方案。  相似文献   

AN ANALYSIS OF THE ATMOSPHERIC WATER BALANCE OVER THE SOUTHERN HEMISPHERE     

David A. Howarth  John N. Rayner 《自然地理学》2013,34(6):513-535

An analysis of the atmospheric water balance over the Southern Hemisphere is conducted for the time period June 1980 through May 1984 that includes the 1982–1983 El Niño event. Notable spatial and temporal variations are evident in the moisture flux divergence fields, in the mean meridional transport of water vapor, and in the moisture content of portions of the tropical atmosphere that are attributable to the 1982–1983 ENSO event. Estimates of the net gain/loss of atmospheric water are provided for 10° latitude belts; although the magnitudes of the differences between evaporation and precipitation fall within the range of previous estimates, they are most probably underestimated. [Key words: atmospheric water balance, El Niño, hydrologic cycle, southern hemisphere, water vapor flux.]  相似文献   

The August 2007 Heat Wave in North Carolina: Meteorological Factors and Local Variability     

《自然地理学》2013,34(3):217-240

August 2007 was an exceptionally warm month across North Carolina. Hundreds of daily maximum and daily high minimum temperature records, as well as numerous all-time temperature records, were either tied or broken during the month. At the same time, a drought of historic proportions overspread much of the Southeast United States. A critical aspect of the August 2007 heat wave was the observed variability in heat and humidity across the different geographic regions of North Carolina. The highest maximum temperatures occurred most frequently in the Piedmont and Sandhills regions, while minimum temperatures were exceptionally high along the coast. The broad-scale pattern of heat can be tied to adiabatic warming associated with subsidence downstream of a persistent upper-level ridge centered over the Mississippi River Valley. Regional to local variations in the heat and humidity across North Carolina are linked to upwind sensible heat fluxes associated with major soil moisture deficits, adiabatic warming connected with downsloping winds off the Appalachian Mountains, and the depth of the mixing layer. Along the coast, the pattern of heat and humidity was tied to the positioning of a mesoscale thermal trough and the presence and strength of the sea-breeze circulation.  相似文献   

Synoptic conditions of heavy snowfalls in Europe     

Ewa Bednorz 《Geografiska Annaler: Series A, Physical Geography》2013,95(1):67-78

Synoptic conditions of heavy snowfalls at four stations in Europe (Oslo, Bremen, Smolensk and Budapest) were analyzed using daily data of snow cover depth from 50 winter seasons (1960/1961–2009/2010). Composite maps of the sea level pressure and 500 hPa geopotential height means and anomalies were presented for the days with an increase in snow depth by ≥10 cm, for each station separately. In the same way, maps were presented for the 850 hPa temperature and the precipitable water content. Additionally, 48 h back trajectories of air masses for the chosen days with the highest amount of snowfall were constructed, using the NOAA HYSPLIT model. Negative anomalies of sea level pressure and 500 hPa heights, which correspond to low‐pressure systems spreading over Europe, are prerequisites for the occurrence of heavy snowfalls at each analyzed location. In Budapest, heavy snowfalls appear as a result of cyclonic cold fronts from the Mediterranean Sea. Another typical location of snow‐bringing low‐pressure systems is the Baltic Sea region. Negative pressure anomalies over the North Atlantic with a low‐pressure centre over the Norwegian Sea cause snowfalls in Oslo. There are two main sources of air masses bringing abundant snowfalls in Europe: the Atlantic region and Mediterranean. According to back trajectories, the humid air masses are transported over long distances and on the way they are shifted from the low troposphere in the source regions to the upper layers.  相似文献   

A new map of the Mitdluagkat glacier—a preliminary report     

Bent Hasholt M.Sc. 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(1):19-21

Hasholt, Bent: A new map of the Mitdluagkat glacier—a preliminary report. Geografisk Tidsskrift 87: 19–21, Copenhagen June 1987.

A new map covering the whole Mitdluagkat Glacier has been elaborated. The map is based on air photos from Geodetic Institute in scale 1:150,000 taken July 30, 1981. The scale of the new map is 1:20,000 with 10-m contour intervals. Preliminary field tests indicate that the map is so accurate that it might be used for comparative studies of long-term variations in mass balance of the glacier.  相似文献   

成都经济区近地表大气尘地球化学基线     

施泽明  倪师军  张成江  阚泽忠  葛良全 《地质通报》2012,31(1):90-96

成都经济区近地表大气尘中重金属元素含量空间分布显示,经济区中东部高于西部,北部高于中南部,重工业城市高于综合性城市和旅游城市,工矿影响区元素含量总体偏高,人口密集的平原区高于山区。通过标准极限方法确定了近地表大气尘中元素的“极限浓度”,以低于“极限浓度”值统计确定了地球化学基线值：As为28.6mg/kg 、Hg 0.63mg/kg 、Cd 2.94mg/kg、Cr 110mg/kg、Pb 281mg/kg、Ni 32mg/kg、Zn 535mg/kg。近地表大气尘中元素地球化学基线与区域地质背景和矿产开发有关,矿业活动、工业活动及居民生活是造成近地表大气尘中人为扰动元素含量偏高的主要原因。  相似文献   

工业γ射线探伤机辐射环境影响调查及评价     

余西垂  陈志平 《铀矿地质》2012,28(2):124-128

从探伤机工作原理、有关标准规范、辐射环境影响等方面,结合某企业γ射线探伤机周围空气比释动能率实测数据,分析评价了射线探伤机使用过程中对周围环境的辐射影响程度和影响范围,提出相应的辐射安全管理及辐射防护措施。  相似文献   

Tectonics of the Western Carpathians in the light of recent studies     

《Geodinamica Acta》2013,26(1-3):1-2

During an annual cycle the affect of microclimatic changes (of natural and anthropogenic origin) on the geochemical characteristics of seepage water and mineral precipitation rates was analyzed for two karstic caves which contrast in environmental stability and energy exchange with exterior. On the one hand, Castañar cave (Caceres, Spain) is an extremely controlled show cave with limited visitation showing a minimum exchange rate of energy with the external atmosphere and, secondly, Canelobre cave (Alicante, Spain), is a widely visited cave where the anthropogenic impact generates rapid and high-energy environmental changes. Mineral saturation state of seepage water of both caves is controlled by microclimatic variations, such as: 1) natural underground air renewal through the porous system of the upper soil and the network of host-rock fissures, or elso through the cave entrance, 2) cumulative disruptions in the pCO2 levels of cave air due to the presence of visitors, and 3) forced ventilation of the subterranean atmosphere due to the uncontrolled opening of cave entrances. The obtained results reinforce the significance of the microclimatic fluctuations on short time scales in the dynamics of the subterranean karst systems, in terms of rates of mineral precipitation and growth of speleothems, as well as their key role for cave conservation.  相似文献