README for FRAPPE-AERI_GROUND-BAO-TOWER data

PI_CONTACT_INFO: 
Nadia Smith
University of Wisconsin - Madison,  Space Science and Engineering Center (SSEC)
1225 W. Dayton St. Madison, WI 53706
608-265-5653
nadia.smith@ssec.wisc.edu

DATA TYPE: Atmospheric parameters retrieved from upwelling infrared hyperspectral measurements
PLATFORM: AERI (Atmospheric Emitted Radiance Interferometer) on the SPARC (SSEC Portable Atmospheric Research Center)
LOCATION:  Lat: 40.0451, Lon: 105.0058, Elevation: 1590.0 m
PROJECT_INFO:  Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ) / Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ); located at the Boulder Atmospheric Observatory (BAO) in Erie, CO; 16 July – 16 August 2014

DATA RETRIEVAL METHOD: The algorithm used to process the AERI radiance measurements was originally developed by William L. Smith Sr. (bill.l.smith@cox.net) for LRTech, DOE, and NGA for the purpose of retrieving thermodynamic and trace gas profiles from the radiative measurements with the ASSIST instrument. The ASSIST algorithm was used here with AERI measurements during the FRAPPÉ/DISCOVER-AQ program because of its unique capability to retrieve trace gas profiles. Here the AERI measurements conducted at the Boulder Tower are transformed into vertical profiles of temperature, humidity, carbon monoxide, ozone, methane, and nitrous oxide. In short, the retrieval is performed in two steps, a clear-/cloudy-sky regression followed by physical bias-correction. The RAQMS (Realtime Air Quality Modeling System) reanalysis fields (http://raqms-ops.ssec.wisc.edu/) are used as first guess in the bias-correction step, so that the resultant retrieves closely resemble RAQMS values, but with higher temporal and vertical resolution. Please contact the PI, Nadia Smith, for a detailed report on this method. 

DATA DESCRIPTION: Atmospheric profile parameters range in height from 0 km to ~2.5 km along 35 vertical levels. These retrievals have not been validated and the authors wish to be contacted before use in research or publication. 

HDF5 FILES CONTAIN THE FOLLOWING DATA FIELDS:
[fieldname] = [description]; [units]; [data dimension], with [ns x nlev] denoting ["number of samples" x "number of vertical levels"]

/Attributes/Longitude = Longitude, [decimal degrees]; [1]
/Attributes/Latitude = Latitude, [decimal degrees]; [1]
/Attributes/Pressure = Vertical pressure vector; [hPa]; [ns x nlev]
/Attributes/Altitude = Vertical height vector; [km]; [ns x nlev]
/Attributes/Time = UTC time of AERI measurement; [decimal hour]; [ns x 1]
/Attributes/Surface_Pressure = AERI measured surface pressure; [hPa]; [ns x 1]
/Attributes/Surface_Temperature = AERI measured surface temperature; [K]; [ns x 1]
/Attributes/Surface_RelHum = AERI measured surface relative humidity; [%]; [ns x 1]
/Attributes/Surface_MixRatio = AERI measured surface water vapor mixing ratio; [g/kg]; [ns x 1]
/Data/RTV_CldBasePressure = Cloud base pressure retrieval; [hPa]; [ns x 1]
/Data/RTV_Temperature = Retrieved atmospheric Temperature profile; [K]; [ns x nlev]
/Data/RTV_MixRatio = Retrieved atmospheric Water Vapor Mass Mixing Ratio profile; [g/kg]; [ns x nlev]
/Data/RTV_RelHum = Retrieved atmospheric Relative Humidity profile; [%]; [ns x nlev]
/Data/RTV_profile_O3 = Retrieved atmospheric Ozone profile; [ppmv]; [ns x nlev]
/Data/RTV_profile_CO = Retrieved atmospheric Carbon Monoxide profile; [ppmv]; [ns x nlev]
/Data/RTV_profile_CH4 = Retrieved atmospheric Methane profile; [ppmv]; [ns x nlev]
/Data/RTV_profile_N2O = Retrieved atmospheric Nitrous Oxide profile; [ppmv]; [ns x nlev]
/Data/FG_Temperature = First Guess atmospheric Temperature reanalysis field from RAQMS; [K]; [ns x nlev]
/Data/FG_MixRatio = First Guess atmospheric Water Vapor Mass Mixing Ratio reanalysis field from RAQMS; [g/kg]; [ns x nlev]
/Data/FG_RelHum = First Guess atmospheric Relative Humidity reanalysis field from RAQMS; [%]; [ns x nlev]
/Data/FG_profile_O3 = First Guess atmospheric Ozone reanalysis field from RAQMS; [ppmv]; [ns x nlev]
/Data/FG_profile_CO = First Guess atmospheric Carbon Monoxide reanalysis field from RAQMS; [ppmv]; [ns x nlev]
/Data/FG_profile_CH4 = First Guess atmospheric Methane reanalysis field from RAQMS; [ppmv]; [ns x nlev]
/Data/FG_profile_N2O = First Guess atmospheric Nitrous Oxide reanalysis field from RAQMS; [ppmv]; [ns x nlev]