A Comprehensive Archive of Aerosol and Trace Gas Spatial Distributions for Model and Satellite Validation

Abstract:

The University of Denver Aerosol Group has assembled measured aerosol size distributions, gaseous concentrations, and atmospheric state variables covering a 30 year time period into one comprehensive archive. Measurements were made during the period 1987-2013 and include data from a total of 21 NASA field campaigns. Measurements were taken from the ground to over 21 km in altitude, from 72 S Latitude to 90 N latitude on over 300 individual flights on NASA Research Aircraft.

Aerosol measurements were made with the University of Denver’s Nucleation-Mode Aerosol Size Spectrometer (NMASS), Focused Cavity Aerosol Spectrometer, and/or a low-pressure Condensation Particle Counter (CPC) depending on the specific campaign. The science payloads varied with the campaign objectives, but the aerosol data were invariably acquired in conjunction with measurements by other investigators placing them in the context of atmospheric composition. The archive includes location and time of the measurements along with the tropopause heights and selected atmospheric composition and state data such as ambient temperatures and pressures, abundances of ozone, N₂O, oxides of nitrogen, water vapor, CO₂ etc.

The data archive is stored in NetCDF format and includes all relevant metadata for measured quantities. This archive will be hosted by NASA and will be available to the public for model validation. The data includes indexing by scientific campaign, date, and spatial coordinates. This will facilitate comparisons across the available range of times, locations and related measurements.

This data set has been used for validation of satellite remote sensing data. Coincident measurements of aerosol size distributions were used to calculate extinction profiles which were compared to those retrieved with the SAGE II satellite. Agreement between extinctions derived from the in situ size measurements and those provided by SAGE II was good for the 452, 525, and 1020 nm wavelength channels, but poor for the 386 nm channel.

Profiles of aerosol number concentrations measured over the altitude range from 4 to 20 km are provided for 11 locations ranging from Punta Arenas, Chile (53 S) to Kiruna, Sweden (67 N). Profiles of aerosol surface area concentration and aerosol volume concentration are provided for 7 locations spread from 43 S to 67 N.