Data coverage
The objective of this limited edition data collection is to examine the ammonia products generated by the ESSPA (Earth System Science Profiling Algorithm) algorithm from the Cross-track Infrared Sounder (CrIS) instruments. The CrIS instrument used for this product is deployed on board the Suomi National Polar-orbiting Partnership (SNPP) platform and uses the Normal Spectral Resolution (NSR) data. The CrIS instrument is a Fourier transform spectrometer with a total of 1305 NSR infrared sounding channels covering the longwave (655-1095 cm-1), midwave (1210-1750 cm-1), and shortwave (2155-2550 cm-1) spectral regions. The NH3 L2 ammonia algorithm is based on an AER (Atmospheric and Environmental Research, Inc.) program initially developed to process TES (Tropospheric Emissions Spectrometer) trace gas products. This version runs within the ESSPA software framework: it uses the AER OSS forward model and an optimal estimation approach with a Levenberg-Marquardt algorithm. Temperature and water profiles are obtained from the CLIMCAPS Field of Regard (FOR) products, as are initial guesses for surface temperature and emissivity. The algorithm consists of a two-step sequential retrieval the first step retrieves surface temperature and emissivity and the second step an ammonia profile. The algorithm produces ammonia retrievals on every field of view (FOV) in each FOR. A level 2 granule has been set as 6 minutes of data, 30 footprints crosstrack by 45 lines along track. There are 240 granules per day, with an orbit repeat cycle of approximately 16 day. SNDRSNCrISL1BIMG The Cross-track Infrared Sounder (CrIS) Level 1B Normal Spectral Resolution (NSR) data files contain radiance measurements along with ancillary spacecraft, instrument, and geolocation data of the CrIS instrument on the Suomi National Polar-orbiting Partnership Project (SNPP). In December 2014, the CrIS instrument on the SNPP satellite doubled the spectral resolution of shortwave infrared data being transmitted to the ground. In November 2015, additional points were included at the ends of the longwave and shortwave interferograms to improve the quality of the calibration. Prior to November 2, 2015 the data are only available in Normal Spectral Resolution, after November 2, 2015 at 16:06 UTC, the data are available in both NSR and Full Spectral Resolution (FSR). The NSR files have 1,317 channels: 163 shortwave channels from 3.9 to 4.7 microns (2555 to 2150 cm-1), 437 midwave channels from 5.7 to 8.05 microns (1752.5 to 1242.5 cm-1), and 717 longwave channels from 9.1 to 15.41 microns (1096.25 to 648.75 cm-1). Each CrIS field-of-regard (FOR) contains 9 field-of-views (FOVs) arranged in a 3X3 array. The Level 1B files contain 30 FORs in the cross track direction and 45 in the along track direction. Data products are constructed on six minute boundaries. The Visible Infrared Imaging Radiometer Suite (VIIRS) has 22 imaging and radiometric bands covering wavelengths from 0.41 to 12.5 microns. It provides the sensor data records for clouds, sea surface temperature, ocean color, and others. This IMG product primarily contains statistics of the VIIRS cloud mask and VIIRS L1B data within each CrIS footprint.. AERDTL2VIIRSSNPP The SNPP Visible Infrared Imaging Radiometer Suite (VIIRS) NASA standard Level-2 (L2) dark target (DT) aerosol product provides satellite-derived measurements of Aerosol Optical Thickness (AOT) and their properties over land and ocean, and spectral AOT and their size parameters over oceans every 6 minutes, globally. The VIIRS incarnation of the DT aerosol product is based on the same DT algorithm that was developed and used to derive products from the Terra and Aqua missions’ Moderate Imaging Spectroradiometer (MODIS) instruments. Two separate and distinct DT algorithms exist. One helps retrieve aerosol information over ocean (dark in visible and longer wavelengths), while the second aids retrievals over vegetated/dark-soiled land (dark in the visible wavelengths). This orbit-level product (Short-name: AERDTL2VIIRSSNPP) has an at-nadir resolution of 6 km x 6 km, and progressively increases away from nadir given the sensor’s scanning geometry and Earth’s curvature. Viewed differently, this product’s resolution accommodates 8 x 8 native VIIRS moderate-resolution (M-band) pixels that nominally have ~750 m horizontal pixel size. Hence, the Level-2 Dark Target Aerosol Optical Thickness data product incorporates 64 (750 m) pixels over a 6-minute acquisition. Version 2.1 constitutes the latest collection of the SNPP VIIRS L2 Dark Target Aerosol product and contains improvements over its previous collection (v2.0). For more information consult LAADS product description page at: https://ladsweb.modaps.eosdis.nasa.gov/missions-and-measurements/products/AERDTL2VIIRSSNPP Or, Dark Target aerosol team Page at: https://darktarget.gsfc.nasa.gov/ AERDBDTD10KML3VIIRSSNPP This High-Resolution (0.1 x 0.1 degree) Level 3 daily Aerosol Optical Depth (AOD) product is generated by combining two Visible Infrared Imaging Radiometer Suite (VIIRS) operational algorithms, namely Deep Blue (DB) and Dark Target (DT), on board the Suomi National Polar-Orbiting Partnership (SNPP) satellite. This dataset is provided in daily files ranging from 2012-03-04 to the present. The spatial coverage is global and the dataset is gridded at 0.1 x 0.1 degree spatial resolution. The data are generated using Level 2 AOD retrieved using DT and DB algorithms. The product provides multiple options for using data either from DT or DB or combined. Depending on user need and application, they can choose one or more relevant parameter. The pixels with highest quality as recommended by science teams are only considered in these averaging. In addition to averaged AOD at 0.1 x 0.1 degree resolution, standard deviation and number of pixels averaged from each algorithm are also provided. Average sensor zenith angle is also provided for additional filtering of the data. If you have any questions, please read the README document first and post your question to the NASA Earthdata Forum (forum.earthdata.nasa.gov) or email the GES DISC Help Desk ([email protected]). AERDBDTM10KML3VIIRSSNPP This High-Resolution (0.1 x 0.1 degree) Level 3 monthly Aerosol Optical Depth (AOD) product is generated by combining two Visible Infrared Imaging Radiometer Suite (VIIRS) operational algorithms, namely Deep Blue (DB) and Dark Target (DT), on board the Suomi National Polar-Orbiting Partnership (SNPP) satellite. This dataset is provided in monthly files ranging from March 2012 to the present. The spatial coverage is global and the dataset is gridded at 0.1 x 0.1 degree spatial resolution. The data are generated using Level 2 AOD retrieved using DT and DB algorithms. The product provides multiple options for using data either from DT or DB or combined. Depending on user need and application, they can choose one or more relevant parameter. The pixels with highest quality as recommended by science teams are only considered in these averaging. In addition to averaged AOD at 0.1 x 0.1 degree resolution, standard deviation and number of pixels averaged from each algorithm are also provided. Average sensor zenith angle is also provided for additional filtering of the data. If you have any questions, please read the README document first and post your question to the NASA Earthdata Forum (forum.earthdata.nasa.gov) or email the GES DISC Help Desk ([email protected]). SNDRSNML2RMS This SNDRSNM2RMS level 2 product is generated by the RAMSES (Retrieval Algorithm for Microwave Sounders in Earth Science) II algorithm. Different from the CLIMCAPS (Community Long-term Infrared Microwave Coupled Product System) algorithm, the RAMSES II algorithm is a microwave only retrieval algorithm. While the CLIMCAPS uses measurements from both Cross-track Infrared Sounder (CrIS) and Advanced Technology Microwave Sounder (ATMS) instruments, also known as CrIMSS (Cro
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