MAS Appendix

The eMAS aerosol products generated by the Dark Target research group at NASA: Goddard Space Flight Center are provided in Hierarchical Data Format (HDF4) and use a filename structure that reflects both its MAS and MODIS heritage (e.g. eMASL2AER.FFFFF_TT_YYYYMMDD_HHMM_HHMM_yyyymmdd_hhmm.hdf, where FFFFF_TT is flight_track info, YYYYMMDD is the date of flight, HHMM_HMMM is beginning and ending time of flight track, and yyyymmdd_hhmm is the processing time). Data are available from: https://asapdata.arc.nasa.gov/emas/data/deploy_html/seac4rs_home.html. Quicklook imagery is available from https://modis-images.gsfc.nasa.gov/SEAC4RS/emas/emas_seac4rs_L2_imagery.html.

Table A1: SDSs and attributes contained in eMASL2AER file: SDSs are listed alphabetically, and information includes: the name of SDS, the variable type (as stored within the file), the scaling factor, the valid range after scaling (1 = minimum, 2 = maximum), the dimensions of the SDS, and the Long_Name (description within the file).

SDS Name	Type	units	scale	valid(1)	valid(2)	DimList	Long_Name
Aerosol_Cldmask_Land_Ocean	short	None	1.0	0.0	1.0	X,Y	Cloud Mask 0= cloud 1= clear
Aerosol_Cloud_Fraction_Land	short	None	0.001	0.0	1.0	X10,Y10	Cloud fraction from Land aerosol cloud mask from retrieved and overcast pixels not including cirrus mask
Aerosol_Cloud_Fraction_Land_and_Ocean	short	None	0.001	0.0	1.0	X10,Y10	Cloud fraction from Land and Ocean merged together
Aerosol_Cloud_Fraction_Ocean	short	None	0.001	0.0	1.0	X10,Y10	Cloud fraction from Ocean aerosol cloud mask from retrieved and overcast pixels not including cirrus mask
Aerosol_Type_Land	short	None	1.0	0.0	4.0	X10,Y10	Aerosol Type: 1 = Continental, 2 = Moderate Absorption Fine, 3 = Strong Absorption Fine, 4 = Weak Absorption Fine, 5 = Dust Coarse
Aircraft_Altitude	Int	Meters MSL				Y	Aircraft Altitude mean value for 10*10 box
Angstrom_Exponent_1_Ocean	short	None	0.001	-1.0	5.0	X10,Y10	Calculated Angstrom Exponent for 0.55 vs 0.86 micron
Angstrom_Exponent_2_Ocean	short	None	0.001	-1.0	5.0	X10,Y10	Calculated Angstrom Exponent for 0.86 vs 2.11 micron
Corrected_Optical_Depth_Land	short	None	0.001	-1.0	5.0	X10,Y10,3LB	Retrieved AOT at 0.47, 0.55,0.65 micron
Corrected_Optical_Depth_Land_wav2p1	short	None	0.001	-1.0	5.0	X10,Y10	Retrieved AOT at 2.11 micron
Effective_Optical_Depth_Average_Ocean	short	None	0.001	-1.0	5.0	X10,Y10,7	Retrieved AOT at 0.47,0.55,0.65,0.86,1.24,1.63,2.11 (1.24 has fill values)micron
Error_Flag_Land_And_Ocean	Short	None	1.0	1	26	X10,Y10,2S	Error code 1 26 Layer 1 ocean Layer 2 land Ask for Documentation
Fitting_Error_Land	short	None	0.001	0.0	1.0	X10,Y10	Spectral Fitting error for inversion over land
Glint_Angle	int	Degrees	0.0001	0.0	180.0	X10,Y10	Glint Angle
Image_Optical_Depth_Land_And_Ocean	short	None	0.001	-1.0	5.0	X10,Y10	AOT at 0.55 micron for both ocean and land with all quality data (Quality flag=0,1,2,3)
Land_Ocean_Quality_Flag	short	None	1.0	0.0	3.0	X10,Y10	Quality Flag for Land and ocean Aerosol retreivals 0= bad 1 = Marginal 2= Good 3=Very Good)
Land_sea_Flag	short	None	1.0	1.0	2.0	X10,Y10	Land_sea_Flag (0 = Ocean, 1 = Land 2 = Coastal)
Latitude #	long	Deg East	1	-180	180	X10,Y10	Geodetic Latitude
Least_Squares_Error_Ocean	short	None	0.001	0.0	1.0	X10,Y10	Residual of least squares fitting for inversion over Ocean
Longitude #	long	Deg North	1	-90	90	X10,Y10	Geodetic Longitude
Mean_Reflectance_Land	short	None	0.0001	0.0	1.0	X10,Y10,7	Mean reflectance of pixels used for land retrieval at 0.47,0.55,0.65,0.86,1.24,1.63,2.11 (1.24 has fill values)micron
Mean_Reflectance_Ocean	short	None	0.0001	0.0	1.0	X10,Y10,7	Mean reflectance of pixels used for ocean retrieval at 0.47,0.55,0.65,0.86,1.24,1.63,2.11 (1.24 has fill values)micron
Number_Pixels_Used_Land	short	None	1.0	1.0	100.0	X10,Y10,2L	Number of pixels used for land retrieval at 0.47 and 0.65 micron
Number_Pixels_Used_Ocean	short	None	1.0	1.0	100.0	X10,Y10,7	Number of pixels used for ocean retrieval at 0.47,0.55,0.65,0.86,1.24,1.63,2.11 (1.24 has fill values)micron
Optical_Depth_Land_And_Ocean	short	None	0.001	-1.0	5.0	X10,Y10	AOT at 0.55 micron for both ocean (Quality flag=1,2,3) and land (Quality flag=3)
Optical_Depth_Large_Average_Ocean	short	None	0.001	-1.0	5.0	X10,Y10,7	Retrieved AOT of large mode for 'average' solution at 0.47, 0.55,0.65,0.86,1.24,1.63,2.11 um
Optical_Depth_Ratio_Small_Land	short	None	0.001	0.0	1.0	X10,Y10	Fraction of AOT (at 0.55 micron) contributed by fine dominated model
Optical_Depth_Ratio_Small_Ocean_0.55micrn	short	None	0.001	0.0	1.0	X10,Y10	Fraction of AOT (at 0.55 micron) contributed by fine mode
Optical_Depth_Small_Average_Ocean	short	None	0.001	-1.0	5.0	X10,Y10,7	Retreived optical thickness for fine mode for 0.47,0.55,0.65,0.86,1.24,1.63,2.11 (1.24 has fill values)micron
Sensor_Azimuth #	int	Degrees	0.0001	-180.0	180.0	X10,Y10	Sensor_Azimuth Angle, Cell to Sun
Sensor_Zenith #	int	Degrees	0.0001	0.0	180.0	X10,Y10	Sensor_Zenith Angle, Cell to Sensor
Solar_Azimuth #	int	Degrees	0.0001	-180.0	180.0	X10,Y10	Solar_Azimuth Angle, Cell to Sun
Solar_Zenith #	int	Degrees	0.0001	0.0	180.0	X10,Y10	Solar Zenith Angle, Cell to Sun
Solution_Index_Ocean_Large	short	None	1.0	5.0	9.0	X10,Y10	index identifying coarse mode from Look Up Table for 'best' solution
Solution_Index_Ocean_Small	short	None	1.0	1.0	4.0	X10,Y10	index identifying fine mode from Look Up Table for 'best' solution
STD_Reflectance_Land	short	None	0.0001	0.0	1.0	X10,Y10,7	Standard deviation of reflectance of pixels used for land retrieval at 0.47,0.55,0.65,0.86,1.24,1.64,2.11 (1.24 has fill values)microns
STD_Reflectance_Ocean	short	None	0.0001	0.0	1.0	X10,Y10,7	Standard deviation of reflectance of pixels used for ocean retrieval at 0.47,0.55,0.65,0.86,1.24,1.64,2.11 (1.24 has fill values)microns
Surface_Reflectance_Land	short	None	0.001	0	1.0	X10,Y10,3LA	Estimated Surface Reflectance at 0.47,0.65 and 2.11micron
Topographic_Altitude_Land	short	km	0.001	0.0	1.0	X10,Y10	Averaged topographic altitude (in km) for Land
Wind_Speed_Ncep_Ocean	short	m/s	0.001	0	8.0	X10,Y10	Wind Speed based on NCEP reanalysis for Ocean

X,Y refers to a 2-dimensional array along/across the swath (Cell_Along_Swath, Cell_Across_Swath)
- X10,Y10 refers to 10x10 aggregation of native pixels:(Cell_Along_Swath(10*10)=variable, Cell_Across_Swath(10*10)=71)
Some parameters have a 3^rd dimension (Z)
- 7 = seven wavelengths: 0.47, 0.55,0.65,0.86,1.24,1.63,2.11 mm, where 1.24 is always missing (fill values)
- 3LA = three wavelengths: 0.47, 0.55, 0.65 mm
- 3LB = three wavelengths: 0.47, 0.65, 2.11 mm
- 2L = two wavelengths: 0.47, 0.65 mm
- 2S = two surfaces: Ocean and Land
Note that most SDSs are stored as integer format, so the scale must be applied as a multiplier to derive the physical units.
Valid(1) and Valid(2) represent the minimum and maximum valid values for a particular SDS (usually in integer form).
# represents SDSs aggregated directly from L1B.