The GPM Ground Validation Upper Air Radiosonde OLYMPEX dataset was collected from October 28, 2015 through January 16, 2016 during the GPM Ground Validation Olympic Mountain Experiment (OLYMPEX) held on the Olympic Peninsula in the Pacific Northwest of the United States. Radiosondes were released from 5 locations: 3 in US - KSLE, KUIL, and NPOL site; and 2 in Canada - ECCC instrument site and CYZT. A total of 651 radiosondes were launched and collected during OLYMPEX from these sites. In addition, Level 4 dropsonde data were reprocessed to match the Level-4 data format and content of the radiosonde files and is also provided here. The dropsondes were released from the NASA DC-8 aircraft during specific flights in December 2015 and are published as the AVAPS dataset. This Upper Air Radiosonde dataset contains Level 0 through Level 4 data containing dew point temperature, pressure, air temperature, relative humidity, horizontal wind speed, vertical wind speed, wind direction, rise or drop rate, and geopotential height measurements. The data files are available in ASCII, ASCII-EOL, and netCDF-3 formats, as well as Skew-T and time series plots in PNG format. The lower level datasets (Level 0 raw data through Level 2 data) are only available upon request from the NASA GHRC DAAC.

The GPM Ground Validation UNCA Upper Air Radiosonde IPHEx dataset was collected from April 29, 2014 through June 12, 2014 during the GPM Ground Validation Integrated Precipitation and Hydrology Experiment (IPHEx) held in North Carolina. The goal of IPHEx was to characterize warm season orographic precipitation regimes and the relationship between precipitation regimes and hydrologic processes in regions of complex terrain. These radiosonde data files include pressure, geometric height, temperature, relative humidity, dew point temperature, wind direction, and wind speed measurements at various levels of the troposphere. The data are available in ASCII-tsv format files, and browse imagery are available as Portable Network Graphics (PNG) format files.

The GPM Ground Validation Kumpula Mast Meteorological Data LPVEx dataset is comprised of temperature, radiation, and wind measurements collected by the Station for Measuring Ecosystem-Atmosphere Relations III (SMEAR III) Kumpula Mast in Helsinki, Finland. This occurred during the Global Precipitation Measurement (GPM) mission Light Precipitation Validation Experiment (LPVEx) field campaign. This field campaign took place around the Gulf of Finland, aiming to provide additional high-latitude, light rainfall measurements for the improvement of GPM satellite precipitation algorithms. These meteorological dataset files are available from September 17 through October 21, 2010 in ASCII text format.

The GPM Ground Validation Physicum Building Mast Meteorological Data LPVEx dataset consists of meteorological data (temperature, pressure, wind, precipitation, and radiation) collected from the Station for Measuring Ecosystem-Atmosphere Relations III (SMEAR III) at the University of Helsinki’s Physicum building rooftop weather station in Helsinki, Finland. These data were collected during the Global Precipitation Measurement (GPM) mission Light Precipitation Validation Experiment (LPVEx) field campaign that took place around the Gulf of Finland, aiming to provide additional high-latitude, light rainfall measurements for the improvement of GPM satellite precipitation algorithms. These meteorological data files are available from September 16 through October 22, 2010 in ASCII-CSV and ASCII text formats.

The GPM Ground Validation Duke Microwave Radiometer (MWR) IPHEx dataset consists of data collected by the MWR, which is a sensitive microwave radiometer that detects the microwave radiances at two frequencies: 23.8 and 31.4 GHz. The measurements are are used to determine the presence of vapor and liquid water molecules in the atmosphere along with other derived parameters. These data were obtained during the Integrated Precipitation and Hydrology Experiment (IPHEx) field experiment, which was held in North Carolina with the goal to characterize warm season orographic precipitation regimes and the relationship between precipitation regimes and hydrologic processes in regions of complex terrain. These data are available for May 1, 2014 through June 15, 2014 and are in netCDF-3 format.

The GPM Ground Validation Environment Canada (EC) Radiosonde GCPEx dataset provides measurements of pressure, temperature, humidity, and winds collected by Vaisala RS92 Radiosondes during the GPM Cold-season Precipitation Experiment (GCPEx) at the CARE site in Ontario, Canada, January 17, 2012 through February 29, 2012. GCPEx addressed shortcomings in the GPM snowfall retrieval algorithm by collecting microphysical properties, associated remote sensing observations, and coordinated model simulations of precipitating snow. These data sets were collected to aid in the achievement of the over arching goal of GCPEx which is to characterize the ability of multi-frequency active and passive microwave sensors to detect and estimate falling snow.

The GPM Ground Validation Advanced Vertical Atmospheric Profiling System (AVAPS) OLYMPEX dataset contains dropsonde vertical profiles of atmospheric pressure, air temperature, dew point temperature, relative humidity, wind direction and magnitude, and sensor location obtained during the Olympic Mountains Experiment (OLYMPEX). The AVAPS dropsondes were released during specific NASA DC-8 aircraft flights between November 12, 2015 and December 19, 2015. A total of 53 standard research dropsondes were launched in the Pacific ocean off the coast of Washington state collecting atmospheric profile observations. The AVAPS datasets are available in ASCII-eol text format.

The GPM Ground Validation Albert Head (AHD) Ground Meteorological Station (MET) OLYMPEX dataset consists of precipitation rate, reflectivity, pressure, temperature, relative humidity, wind speed, and wind direction data which were measured by the MET station instruments operated by the Environment and Climate Change Canada (ECCC) and located in Albert Head, B.C., Canada. The MET station was comprised of a Vaisala FD12P Visibility Sensor, an OTT Parsivel2 Present Weather Sensor, an OTT Pluvio2 Precipitation Gauge, and a Vaisala WXT520 Weather Transmitter. The MET Station was also co-located with a CAX-1 radar to compare measurements from the MET station with the radar scans. These MET Station data files are available from November 13, 2015 through January 17, 2016 in ASCII-CSV and XML formats, with daily browse images of precipitation rate plots in PNG format.

The GPM Ground Validation Environment Canada (EC) Radiometer GCPEx dataset contains retrievals of temperature, water vapor, relative humidity, liquid water profiles and surface parameters acquired by a passive microwave radiometer during the GPM Cold-season Precipitation Experiment (GCPEx) in Ontario, Canada, February 14, 2012 through March 1, 2012. GCPEx addressed shortcomings in the GPM snowfall retrieval algorithm by collecting microphysical properties, associated remote sensing observations, and coordinated model simulations of precipitating snow.

The GPM Ground Validation NASA ER-2 Navigation Data IPHEx dataset was gathered during the GPM Ground Validation Integrated Precipitation and Hydrology Experiment (IPHEx) in North Carolina. The ER-2 Aircraft flew during the IPHEx field campaign to aid in GPM validation. The science instruments onboard the aircraft acted as a proxy for GPM satellite instruments. Twenty-one ER-2 flights occurred during May 1, 2014 through June 14, 2014. The dataset consists of navigation data, as well as meteorological parameters collected by an on-board navigation recorder every second of the flight. The data are available in ASCII and XML formats.