Ship Ron Brown Aerosol total and sub-micron light scattering and backscattering (Quinn)

Ship Ron Brown Aerosol total and sub-micron light scattering and backscattering (Quinn)

Contact person: Trish Quinn,

Measurements of aerosol scattering and hemispheric backscattering coefficients were made with an integrating nephelometer (Model 3563, TSI Inc.) at wavelengths of 450, 550, and 700 nm at approximately 55% RH. Data are reported at the measurement RH, 0 degC, and 1013 mb. Values measured directly by the nephelometer were corrected for an offset determined by measuring filtered air over a period of several hours [Anderson and Ogren, 1998]. Data have been corrected for angular non-idealities, including truncation errors and nonlambertian response, of the nephelometer using the method of Anderson and Ogren [1998].

Measurement RH: The measurement RH was controlled to near 55% RH. The RH was measured inside the nephelometer sensing volume. The measurement RH, T, and P values are given in the data file. Also given are the ambient T and RH measured at 18 masl near the main aerosol inlet on the ship.

Inlet: Two single-stage Berner impactors, one with a D50,aero(55% RH) of 1.1um and one with a D50,aero(55% RH) of 10 um were placed upstream of the nephelometer. An automated valve switched between the two impactors every 15 minutes so that sampling alternated between sub-1 um and sub-10 um aerosol.

Averaging interval: 30 min

Time stamp: Decimal day of year where DOY 75.5 is noon on March 16th. Time given is the mid-point of the 30 min averaging interval.

Time period covered by data: DOY 75.1667 to 109.292 (March 16th - April 19th).

Calibration: The neph was calibrated with air and CO2 during the campaign at the beginning, middle, and end.

Anderson and Ogren, Aer. Sci. Tech., 29, 57 - 69, 1998.

Data can be downloaded in ACF format by following the ASCII link, or in binary netCDF file format by following the netCDF link