Problem with modis MOD04_L2, Depp_Blue_Spectral_Aerosol_Optical_Depth_Land

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samaneh94
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Problem with modis MOD04_L2, Depp_Blue_Spectral_Aerosol_Optical_Depth_Land

by samaneh94 » Mon Apr 04, 2022 3:37 am America/New_York

Hello,
I am trying to use MOD04_L2 data from MODIS.
In the SDS part there is a variable named " Depp_Blue_Spectral_Aerosol_Optical_Depth_Land".
I anticipated to see a variable with more than 3D (2D for longitude and latitude and more dimensions for different wavelengths).
But when I download the data (even in .tif format or in .hdf format) there is a 2D array with no information to talk about which wavelength.

Does any one have any idea about this problem??

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LAADS_UserServices_M
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User Services
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Re: Problem with modis MOD04_L2, Depp_Blue_Spectral_Aerosol_Optical_Depth_Land

by LAADS_UserServices_M » Mon Apr 04, 2022 10:50 am America/New_York

The Science Data Set (SDS) you are referring to is:
Deep_Blue_Spectral_Aerosol_Optical_Depth_Land
If you look at the file header metadata stored in each hdf file, you see following information about this parameter:
16-bit integer, 3 x 203 x 135
Number of attributes = 10
valid_range = 0,5000
_FillValue = -9999
long_name = AOT at 0.412, 0.47, and 0.66 micron for land with all quality data (Quality flag=1,2,3)
units = None
scale_factor = 0.0010000000474974513
add_offset = 0.0
Parameter_Type = Output
Cell_Along_Swath_Sampling = 1,2021,10
Cell_Across_Swath_Sampling = 1,1354,10
Geolocation_Pointer = Internal geolocation arrays

You can find more information about this at:
https://atmosphere-imager.gsfc.nasa.gov/products/aerosol/format-content
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