AIRS/Aqua L3 Daily Standard Physical Retrieval (AIRS-only) 1 degree x 1 degree V006 (AIRS3STD) at GES DISC

The Atmospheric Infrared Sounder (AIRS) is a grating spectrometer (R = 1200) aboard the second Earth Observing System (EOS) polar-orbiting platform, EOS Aqua. In combination with the Advanced Microwave Sounding Unit (AMSU) and the Humidity Sounder for Brazil (HSB), AIRS constitutes an innovative atmospheric sounding group of visible, infrared, and microwave sensors. The AIRS Only Level 3 Daily Gridded Product contains standard retrieval means, standard deviations and input counts. Each file covers a temporal period of 24 hours for either the descending (equatorial crossing North to South @1:30 AM local time) or ascending (equatorial crossing South to North @1:30 PM local time) orbit. The data starts at the international dateline and progresses westward (as do the subsequent orbits of the satellite) so that neighboring gridded cells of data are no more than a swath of time apart (about 90 minutes). The two parts of a scan line crossing the dateline are included in separate L3 files, according to the date, so that data points in a grid box are always coincident in time. The edge of the AIRS Level 3 gridded cells is at the date line (the 180E/W longitude boundary). When plotted, this produces a map with 0 degrees longitude in the center of the image unless the bins are reordered. This method is preferred because the left (West) side of the image and the right (East) side of the image contain data farthest apart in time. The gridding scheme used by AIRS is the same as used by TOVS Pathfinder to create Level 3 products. The daily Level 3 products have gores between satellite paths where there is no coverage for that day. The geophysical parameters have been averaged and binned into 1 x 1 deg grid cells, from -180.0 to +180.0 deg longitude and from -90.0 to +90.0 deg latitude. For each grid map of 4-byte floating-point mean values there is a corresponding 4-byte floating-point map of standard deviation and a 2-byte integer grid map of counts. The counts map provides the user with the number of points per bin that were included in the mean and can be used to generate custom multi-day maps from the daily gridded products. The thermodynamic parameters are: Skin Temperature (land and sea surface), Air Temperature at the surface, Profiles of Air Temperature and Water Vapor, Tropopause Characteristics, Column Precipitable Water, Cloud Amount/Frequency, Cloud Height, Cloud Top Pressure, Cloud Top Temperature, Reflectance, Emissivity, Surface Pressure, Cloud Vertical Distribution. The trace gases parameters are: Total Amounts and Vertical Profiles of Carbon Monoxide, Methane, and Ozone. The actual names of the variables in the data files should be inferred from the Processing File Description document.

大气红外探测仪（AIRS）是一种配备有1200倍分辨率的衍射光栅光谱仪，该仪器搭载于地球观测系统（EOS）第二颗极地轨道平台EOS Aqua上。与高级微波 sounding 单元（AMSU）以及巴西湿度探测仪（HSB）相结合，AIRS 构成了由可见光、红外和微波传感器组成的一项创新大气探测系统。AIRS 独立的三级每日网格化产品包含标准检索手段、标准偏差以及输入计数。每个文件覆盖24小时的时空周期，对应下降轨道（赤道穿越北至南，当地时间上午1:30）或上升轨道（赤道穿越南至北，当地时间下午1:30）。数据从国际日期变更线开始，向西推进（如同卫星后续轨道），以确保相邻网格单元的数据时间差不超过一段时间（约90分钟）。跨越日期变更线的扫描线的两部分包含在单独的三级文件中，根据日期排列，以确保网格单元中的数据点在时间上始终一致。AIRS 三级网格单元的边缘位于日期变更线（180度经线边界）。当绘制时，这会产生一幅以0度经线为中心的地图，除非重新排序了数据箱。这种方法更受欢迎，因为图像的左侧（西边）和右侧（东边）包含的数据在时间上相隔最远。AIRS 所使用的网格化方案与TOVS Pathfinder用于创建三级产品时所使用的方案相同。每日三级产品在卫星路径之间存在缺口，这些缺口在该天没有覆盖。地球物理参数已被平均并归入1 x 1度网格单元中，范围从-180.0度至+180.0度经度和从-90.0度至+90.0度纬度。对于每个4字节浮点平均值的网格图，都有一个相应的4字节浮点标准偏差图和一个2字节整数计数网格图。计数图向用户提供每个数据箱中包含在平均值中的点的数量，并可用于从每日网格化产品中生成定制多日地图。热力学参数包括：地表和海面皮肤温度、地表空气温度、空气温度和水汽的剖面、对流层顶特征、柱状可降水量、云量/频率、云高、云顶气压、云顶温度、反射率、发射率、地表气压、云垂直分布。痕量气体参数包括：一氧化碳、甲烷和臭氧的总量和垂直剖面。数据文件中变量的实际名称应从处理文件描述文档中推断。