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National/regional plots/animations of GASP (GOES Aerosol/Smoke Product) aerosol optical depth (AOD), ta and channel 1 (visible channel) reflectance

Sample regional plot of GASP AOD

Sample GASP ta plot

The Regional plots are defined by US EPA (Environmental Protection Agency) Regions, with Regions 1-3 combined into one view. Regions 4-10 are separate plots. The Regional plots show half-hourly GASP aerosol optical depth (in color contours) and half-hourly GOES channel 1 reflectance for cloud (in gray contours) during the sun-lit time.

GASP aerosol optical depth, ta

The GASP ta used for these plots is based on the GOES Aerosol/Smoke Product (Knapp et al., 2002; Prados et al.,2007), which is derived from the visible channel of GOES (Geostationary Operational Environmental Satellites) imager. The retrieval algorithm runs near-real time with 30-minute interval during sun-lit time and 4x4 km^2 spatial resolution at NOAA (National Oceanic and Atmospheric Administration) /NESDIS (National Environmental Satellite, Data, and Information Service). The retrieved AOD is plotted on a scale of 0.0 to 1.0 with ta > 1.0 shown as dark red.

GOES channel 1 reflectance

The GASP cloud mask is derived from infrared channels 2 and 4 radiances. A ta is not derived for cloud filled pixels, therefore the clouds fields are represented by the channel 1 reflectance to help define synoptic weather features important to the movement of aerosols.

Acknowledgements:
GASP data is being obtained from NOAA/NESDIS/Office of Research and Applications.

References
Knapp, K.R., T.H. Vonder Haar, and Y.J.Kaufman (2002), Aerosol optical depth retrieval from GOES-8: Uncertainty study and retrieval validation over South America, J.Geophys. Res., 107(D7), 4055, doi:10.1029/2001JD00505.
Prados, A.I., S. Kondragunta, P. Ciren, and K.R.Knapp (2007), GOES Aerosol/Smoke Product (GASP) over North America: Comparisons to AERONET and MODIS observations, J. Geophys. Res., 112, D15201, doi:10.1029/2006JD007968.

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