基于MODIS影像的成都地区气溶胶光学厚度反演

成都经济的高速发展导致空气污染,大气污染已经严重威胁人类健康,对其进行调查和监测是有效治理大气污染问题的基础。气溶胶反映了大气层中颗粒物含量的多少或空气污染程度,所以精确探测气溶胶光学厚度具有重要意义。利用遥感技术可以进行重复周期性监测气溶胶光学厚度,覆盖面大,节省人力物力。以MODIS影像为基础数据,利用6S大气传输模式建立查找表,在ENVI软件中完成成都市气溶胶光学厚度的反演,以此达到成都大气监测的目的。     

黄土高原半干旱地区气溶胶特性

利用2006年8月～2007年7月兰州大学半干旱气候与环境观测站CE-318数据产品,对气溶胶光学厚度,大气可降水量及Angstrom波长指数的日变化及季节变化特征进行了分析.同时分析了常规温压湿资料、PW及Angstrom波长指数与气溶胶光学厚度的关系.对CE-318反演得到的PW与微波辐射计由神经网络算法得到的水汽总量进行了相关性分析,认为二者对水汽总量测量能力相当.     

兰州地区MODIS气溶胶光学厚度和空气污染指数相关性研究

利用2009年1 12月兰州地区的MODIS气溶胶光学厚度产品与全球自动观测网(AERONET)SACOL站(104.08 E,35.57 N)数据进行对比分析,相关系数达到0.82,线性拟合的斜率为1.13,截距为0.07,表明MODIS AOD能反映兰州地区气溶胶分布的信息.利用MODIS AOD产品与兰州市空气污染指数做相关分析,二者的相关程度较低.在进行湿度影响因子、气溶胶标高订正后,二者相关性有了较为显著的提高,说明MODIS AOD产品可应用于监测兰州地区大气污染情况.     

卫星遥感监测全球大气气溶胶光学厚度变化

 全球大气气溶胶类型和含量变化与气候变化和大气环境污染密切相关,是气象学、环境学和医学研究关注的热点问题。为认识全球气溶胶分布基本特征,发现和跟踪全球气溶胶显著变化地区,本文利用美国NASA 发布的C6 版MODIS气溶胶光学厚度产品分析全球大气气溶胶光学厚度时空年变化特征及其影响因素;分析气溶胶光学厚度分布与中国霾区的关系,提出霾区治理的气溶胶光学厚度年平均值参考标准。分析2003-2014 年卫星监测的气溶胶光学厚度(AOD)空间分布特征显示,全球气溶胶光学厚度稳定高值区位于亚洲东部及其邻近太平洋海区、印度半岛及其邻近印度洋海区、非洲北部和中部及其邻近大西洋海区;重点变化关注区为俄罗斯西伯利亚东部增量区和南美洲亚马逊平原热带雨林减量区。气溶胶光学厚度高值地区的形成与沙尘暴、火山喷发、生物质燃烧、工业排放等自然源,以及工业污染物排放、交通运输、秸秆焚烧等人类活动造成的人为源气溶胶排放直接相关,并受气象因素和山脉等地形阻挡因素影响,这些因素的稳定性与季节变化最终形成全球气溶胶的时空分布特征。中国东部气溶胶光学厚度年平均值大于0.5 的区域为主要霾天气区,其中华北南部、黄淮、江淮、江汉地区和四川盆地为全球气溶胶光学厚度极端高值区,年平均极端高值达到0.8~1.0,为霾天气常态化发生区;通过全球气溶胶光学厚度量值分析认为,气溶胶光学厚度年平均值0.5 可作为中国大气环境最大承载量,中国东部地区高于此值的区域为主要大气污染控制区,大范围工业生产污染物减排可带来整体环境改善,通过工业结构调整有望降低的气溶胶污染中位比率为33%,平均比率为26.5%。     

利用MODIS遥感大气气溶胶及气溶胶产品的应用

介绍了利用EOS卫星上MODIS传感器遥感大气气溶胶光学厚度(AOD)的技术,总结了作者利用MODIS资料进行的研究工作,包括利用太阳光度计的地面观测进行MODIS 10 km分辨率Level 2气溶胶产品的校验、利用该产品分析我国陆地上空气溶胶光学厚度分布特征、1 km高分辨率气溶胶光学厚度反演、气溶胶光学厚度产品应用于大气污染的分析等.证实MODIS遥感手段获取气溶胶分布,不仅为全球和区域气候变化研究提供了基础数据,而且也为区域环境大气污染的研究提供了新工具.     

新疆博斯腾湖地区气溶胶光学厚度特性地基遥感

为加强新疆戈壁地区沙尘监测,为区域气候变化研究和局地卫星遥感精度验证提供地基观测依据,利用CE-318太阳光度计在博斯腾湖地区2010年4～12月测得的太阳直接辐射数据,应用消光法反演了大气气溶胶光学厚度(AOD)和Ångström波长指数α并分析其变化特征。结果表明,该地区550 nm AOD平均值为0.33±0.22。当α>0.5时,550 nm AOD日均值小于0.25; 当α<0.5时,550 nm AOD日均值大于0.3。AOD日变化在非沙尘天气时有3种类型:平稳型、上升型和下降型。沙尘天气时有3种类型:上升型、早晨傍晚高且午时有低值、早晨傍晚低且午时有高值。AOD季节变化是春季最大,冬秋次之,夏季最小。当地年均大气透明度较好,气溶胶成分单一,沙尘天气是影响当地大气浑浊度的主要原因。     

基于MODIS卫星遥感数据的大气气溶胶光学厚度优选反演方法

通过地面大气气溶胶的测定,可以反映大气浑浊度,进而在某种程度上确定区域的气候效应,其中关键技术是大气气溶胶光学厚度的反演.目前使用的卫星遥感气溶胶光学厚度反演算法中,扩展暗像元法精度较低而V5.2法适用范围较窄.提出了一种优选反演法,通过引入中红外通道表观反射率来选择扩展暗像元法或V5.2法.其中,在V5.2法中添加了Walthall双向反射分布订正.实验对比了相关方法反演的气溶胶光学厚度数据,结果表明所提方法可以弥补扩展暗像元法和V5.2算法各自的不足.     

MODIS气溶胶光学厚度与青岛市市南区空气污染指数的回归分析

以青岛市市南区中国海洋大学鱼山校区为研究区域,利用MODIS二级产品的大气气溶胶光学厚度(aerosol optical thickness,AOT)数据、天空辐射计反演得到的AOT数据以及地面测量的空气污染指数(air pollution index,API)数据,利用统计回归分析方法,建立AOT与API之间的数学模型,考虑了湿度因子对API的影响及校正,并分季节进行了分析.在此基础上,探讨利用卫星遥感气溶胶光学厚度进行大气污染监测的可行性.     

MODIS气溶胶光学厚度产品在地面PM_(10)监测方面的应用研究

利用MODIS(中分辨率成像光谱仪)两年的气溶胶光学厚度(AOD)产品与北京地区API转化得到的PM10质量浓度、北京大学站点直接监测的PM10质量浓度以及香港元朗站点监测的PM10质量浓度做相关性分析,发现二者的直接相关程度较低。将AOD除以气溶胶季节标高,得到地面消光系数,与地面PM10质量浓度相关性提高。对地面消光系数进行相对湿度订正,得到计算的质量浓度,与地面实际观测的PM10质量浓度相关性进一步提高。经过两年时间资料的对比分析,证实气溶胶遥感光学厚度经过垂直和湿度影响订正后,可以应用于地面PM10监测。     

南京市MODIS气溶胶光学厚度与PM10质量浓度的相关性分析

利用NASA MODIS气溶胶光学厚度(AOD)产品与南京市区API转换得到的PM10质量浓度进行了相关性分析;发现二者的直接相关程度较低。对气溶胶光学厚度进行垂直和湿度影响订正后,二者的相关系数显著提高。结合风速和气压等气象因子分季节进行多元回归分析,相关系数进一步提高。分析结果表明卫星遥感气溶胶光学厚度可以作为监测PM10污染分布的有效手段。     

Characteristics of distribution and seasonal variation of aerosol optical depth in eastern China with MODIS products

The accuracy of MODIS aerosol products from the NASA Terra Satellite is validated in comparison with the results of sun-photometer observations in Beijing and Hong Kong. By analyzing the MODIS aerosol products within the period of August 2000 to April 2003, it is believed that human activities are the main source of aerosols in the eastern part of China. This is based on the facts that all areas with relatively high values are consistent with regions of dense population and fast economic development, such as the North China Plain, the Sichuan Basin and the Pearl River Delta. It is also supported by the distribution of 舗gstr鰉 exponents showing that most aerosols in the eastern part of China are closely related to human activities, excepting the strong sandstorm episodes occurring in spring, fall and winter. In contrast to developed countries, the 舗gstr鰉 exponent of urban area in China is lower than its surroundings, indicating that the contribution of local floating dust and soot attributed to human activities is significant. Results presented in this paper provide important data for further research on climatic change and environmental study.     

Analysis of variation trends and causes of aerosol optical depth in Shaanxi Province using MODIS data

The temporal and spatial variations and causes of aerosol optical depth （AOD） in Shaanxi Province were investigated based on the Moderate Resolution Imaging Spectroradiometer （MODIS） derived aerosol data for the period of March 2000-February 2012. The results showed that the distribution of aerosol was largely affected by topography and local economic activities. Heavy aero- sol loading and increasing tendency in AOD was observed in Guanzhong, Hanzhong and Ankang basin, while a reverse tendency was revealed in most other regions. The spatial distribution of aerosol Angstrom wavelength exponent was predominantly related to vegetation coverage in Shaanxi. Airborne dust from ground is an important source of coarse mode aerosols. Vegetation im- provement indicated by an increase in normalized difference vegetation index （NDVI） and a reduction in dust weather led to a gradual decrease in coarse mode AOD to the north of Qinling Mountains in Shaanxi, while anthropogenic activities led to an in- crease in fine mode AOD in other areas except those covered by forests. The main aerosol type gradually shifted to the urban industrial type in Shaanxi.     

改进的MODIS海洋气溶胶本征信息反演算法的验证

介绍了改进的MODIS海洋气溶胶反演算法,并重点对该算法进行了验证,结果表明：（1）改进算法纠正了原算法对较大的气溶胶光学厚度的低估和对较小的气溶胶光学厚度的高估现象;其反演得到的气溶胶光学厚度与AERONET的气溶胶光学厚度的相关系数为0．87,高于原算法与AERONET间气溶胶光学厚度的相关系数（0．84）;且有62．1％的反演结果落在误差限内,高于原算法的60．5％。（2）改进算法纠正了原算法对较大的气溶胶尺度分布参数ηss0的低估和较小的气溶胶尺度分布参数卵。的高估现象;其反演得到的气溶胶尺度分布参数与AERONET的气溶胶尺度分布参数的相关系数为0．89,高于原算法与AERONET间气溶胶尺度分布参数的相关系数（0．8）。     

Validation of MODIS aerosol products by CSHNET over China

The Chinese Sun Hazemeter Network (CSHNET) provides the necessary ground-based observation to validate and assess the applicability of MODIS aerosol optical depth (AOD) products over different ecological and geographic regions in China for the first time. The validation results show that the comprehensive utilization ratio and applicability of MODIS products varied very much over different regions and seasons from August 2004 to July 2005. On the Tibetan Plateau, the comprehensive utili- zation ratio of MODIS data was low: MODIS products only accounted for 16% of the ground-based observation; on average, 31% to 45% of MODIS products fell within the retrieval errors issued by NASA. A similar result was found in northern desert areas with the ratio of MODIS to observation ranging from 15% to 55%, with 7% to 39% of MODIS products within errors. In the remote northeast corner of China, low ratios of MODIS to observation were also found ranging from 14% to 46%, with 49% to 69% of MODIS within errors. The forested sites exhibited moderate ratios of MODIS to observation ranging from 46% to 65%, with 30% to 59% of MODIS within errors. This was similar to numbers observed at sites along eastern seashore of China and inland urban sites with the ratio of MODIS to observation between 63% to 75%, with 25% to 67% of MODIS within errors for sites along eastern seashore of China and 43% to 78%, with 35% to 75% of MODIS within errors for inland urban sites. The ratio of MODIS to observation over agricultural areas ranged from 61% to 89%; 59%-88% of MODIS fell within the retrieval errors. At homogeneous and well vegetated areas, the comprehensive utilization ratio of MODIS products was over 80% and above 70% of MODIS products fell within the retrieval errors in growing season.     

甘肃半干旱区城乡气溶胶光学特性的观测与分析

利用CE318型太阳光度计(532nm波段)在2004年5月-2007年5月的城乡观测资料,反演分析了半干旱地区城乡气溶胶的光学特征.得到了气溶胶光学厚度(AOD)的年季变化,并对不同季节气溶胶的光学厚度以及波长指数的变化规律进行了讨论.结合兰州市郊区资料,对城郊大气气溶胶光学特征进行了对比及原因分析.认为较城市而言,半干旱区乡村大气总体上较城市更为洁净.城市气溶胶受到冬季采暖期等人为因素的影响,出现了AOD冬季大、夏季小的特点.气溶胶主要以工业粉尘和沙尘气溶胶为主,夜间逆温层对AOD的日变化影响较大.乡村春季沙尘天气较多,气溶胶浓度变化受季节的影响,春季AOD最大.气溶胶主控粒子多为沙尘粒子.     

Characteristics of atmospheric aerosol optical depth variation over China in recent 30 years

This note retrieves the annual and monthly mean 0.75 μm aerosol optical depth (AOD) by using the daily direct solar radiation and sunshine duration data of 47 solar stations from 1961 to 1990. The characteristic of AOD variation over China in recent 30 years was analyzed. The results indicate that AOD increased obviously over China from 1961 to 1990. AOD increased most rapidly over the east part of Southwest China, the middle-and-lower reaches of the Yangtze River and the Tibetan Plateau. The increasing trend of AOD is also relatively distinct in North China, the Shandong Peninsula, east part of Qinghai Province, and coastal areas of Guangdong Province. However, in most parts of Northwest China and Northeast China, the increase of AOD is less significant, while in the west part of the Xinjiang Uygur Autonomous Region and some parts of Yunnan Province, AOD shows decreasing tendency. Generally, AOD reaches its maximum in spring and the minimum appears in summer. As to the linear trend, the maximum occurs in spring but the minimum in winter. Among the 47 stations selected in this note, the largest three stations of AOD are Chengdu, Chongqing and Nanchong, respectively, which all lie in the Sichuan Basin, and the smallest value of AOD occurs in Jinghong located in Yunnan Province.     

合肥地区气溶胶光学厚度的时间变化特征

利用太阳辐射计CE318对合肥地区大气气溶胶进行长期系统的观测,对2002年至2007年间的观测数据进行反演分析,得出了气溶胶光学厚度随时间变化的统计特征.结果表明合肥地区气溶胶光学厚度日变化有5种类型;气溶胶光学厚度随月份有波浪式变化,月平均值在4月份和8月份分别达到最大值0.727和最小值0.192;四季中春秋季节的气溶胶光学厚度大于夏冬季节,春季最大0.636,夏季最小0.262;2004年至2007年冬季气溶胶光学厚度有逐年增大的趋势.     

地图符号构成元素的结构模式

在分析地图符号视觉变量的基础上，提出地图符号构成元素的新概念．指出地图符号构成元素由位置、形状、色彩、尺寸、网纹、方向和注记组成．探讨了符号构成元素的设计模式和设计程序     

2007年兰州市冬季大气气溶胶光学厚度特性

利用多波段太阳光度计观测资料,采用光谱消光法,计算2007年兰州市采暖期大气气溶胶光学厚度、Angstrom浑浊度系数和波长指数.分析表明:兰州市2007年冬季与历史同期相比,气溶胶光学厚度较小,浑浊度较低,且多为细粒子.对气溶胶光学厚度与能见度进行了分析、拟合,表明二者变化趋势相反,近似呈指数递减关系.