Cloud properties, fast near-real-time (Aqua, 1 km)

The level-2 MODIS cloud product consists of cloud optical and physical parameters. These parameters are derived using remotely sensed infrared, visible and near infrared solar reflected radiances. MODIS infrared channel radiances are used to derive cloud top temperature, cloud top height, effective emissivity, cloud phase (ice vs. water, opaque vs. non-opaque), and cloud fraction under both daytime and nighttime conditions. MODIS visible radiances are used to derive cloud optical thickness and effective particle radius and cloud shadow effects. Near infrared solar reflected radiance provides additional information in the retrieval of cloud particle phase (ice vs. water, clouds vs. snow). The shortname for this level-2 MODIS cloud product is MYD06_L2.MYD06_L2 consists of parameters at a spatial resolution of either 1- km or 5-km (at nadir). Each MYD06_L2 product file covers a five-minute time interval. This means that for 5-km resolution parameters, the output grid is 270 pixels in width by 406 pixels in length. Every tenth granule has an output grid size of 270 by 408 pixels. For 1-km resolution parameters, the output grid is 1354 pixels in width by 2030 pixels in length and every tenth granule has an output grid size of 1354 by 2040 pixels.MYD06_L2 product files are stored in Hierarchical Data Format (HDF-EOS). All gridded cloud parameters are stored as Scientific Data Sets (SDS) within the file, except two (band number and statistics). These are stored as Vdata(table arrays). Approximately 288 files are produced daily. Nighttime files are smaller than their daytime counterparts since only cloud top properties are retrieved at night.The Collection 6 cloud-top property product changes include new 1 km SDSs in addition to the legacy 5 km SDSs, and a new physical cloud height dataset. New 1 km products include cloud top pressure, IR cloud emissivity, cloud height, overshooting cloud top flag, and cloud phase. The 1 km IR phase product is generated using an updated algorithm while the other 1 km products were designed to be as similar as possible to the 5 km version.And, the Collection 6 Cloud optical/microphysical product changes include expanded/improved pixel-level retrieval uncertainty calculations that are intended to be used in lieu of retrieval QA assignments that are no longer assigned (legacy QA bits are now set to a value of 3 for all successful retrievals). Retrievals are now attempted on a pixel flagged as likely to have a partly cloudy field of view by the so-called clear sky restoral algorithm introduced in C5 processing. Successful retrievals from this pixel population have similar SDS names as the non-flagged pixel population but with ???_PCL??? (for Partly CLoudy) appended to the end of the parameter name; an exception is the uncertainty SDSs where both PCL and non-PCL retrieval uncertainties are kept. Metrics for unsuccessful retrievals (those outside the look-up table solution space) are now provided as well (Retrieval_Failure_Metric_*). Finally, absolute retrievals are provided for the other visible and near-infrared (VNIR) and shortwave infrared band pairs (VNIR and 1.6 ??m, VNIR and 3.7 ??m) instead of as differences relative to the VNIR/2.1 ??m retrieval. For more details regarding dataset changes read the document at http://modis-atmos.gsfc.nasa.gov/products_C006update.html.MYD06_L2 Data Category & ParametersSpatial and Temporal Resolution:latitude,longitudescan start timeSolar and Sensor Viewing Geometry:Solar_Azimuth(daytime,nighttime,all), Solar_Zenith(daytime,nighttime,all), Sensor_Azimuth(daytime,nighttime,all), Sensor_Zenith(daytime,nighttime,all)Cloud Top Parameters (5km):Cloud_Effective_Emissivity_(Day, Night, Nadir, Nadir_Day,Nadir_Night, All), Cloud_Fraction_(Day, Night, Nadir, Nadir_Day,Nadir_Night, All), Cloud_Height_Method, Cloud_Phase_Infrared_(day, night, all), Cloud_Top_Height_(Day, Night, Nadir, Nadir_Day,Nadir_Night, All), cloud_top_method_1km, Cloud_Top_Pressure_From_Ratios, Cloud_Top_Pressure_Infrared, Cloud_Top_Pressure_(Day, Night, Nadir, Nadir_Day,Nadir_Night, All), Cloud_Top_Temperature_(Day, Night, Nadir, Nadir_Day,Nadir_Night, All)Cloud Top Parameters (1km):cloud_top_height_1km, cloud_top_pressure_1km, cloud_top_temperature_1km, , cloud_emiss(11, 12, 13, 85, All)_1km, IRW_Low_Cloud_Temperature_From_COPCloud Optical Properties (1km):Above_Cloud_Water_Vapor_094, Cloud_Effective_Radius_(PCL, 16, 16_PCL,1621, 1621_PCL,37,37_PCL, All) , Cloud_Optical_Thickness_(PCL, 16, 16_PCL,1621, 1621_PCL,37,37_PCL, All), Cloud_Phase_Infrared_1km, Cloud_Phase_Optical_Properties, Cloud_Water_Path_(PCL, 16, 16_PCL,1621, 1621_PCL,37,37_PCL, All)Radiation Parameters:Radiance_Variance, Brightness_Temperature, Spectral_Cloud_Forcing, Surface_Pressure, Surface_Temperature, surface_temperature_1km, Atm_Corr_Refl, Cirrus_ReflectanceQuality Assurance Parameters:Processing flag for 5 km resolution, Cloud_Multi_Layer_Flag, cirrus reflectance flag for 1 km resolution, quality assurance flag for 1 and 5 km resolution, Retrieval_Failure_Metric_(16,1621,37, All), Cloud_Optical_Thickness_Uncertainty_(16,1621,37, All), Cloud_Water_Path_Uncertainty_(16,1621,37, All), Cloud_Effective_Radius_Uncertainty_(16,1621,37, All), cloud mask for 1km, 5km, and SPI, radiance variance for thermal bands, statistics for parameters at 1km resolutionThe MODIS Cloud Product will be used to investigate seasonal and inter-annual changes in cirrus (semi-transparent) global cloud cover and cloud phase with multispectral observations at high spatial (1 kilometer) resolution.For more information about the MYD06_L2 product, visit the MODIS-Atmosphere site at:http://modis-atmos.gsfc.nasa.gov/MOD06_L2/