Earthdata Forum

Hello,

I have a question about the MAIAC Daily Atmosphere (MCD19A2) data product. The link I provided below says this data product includes a layer for aerosol type. However, I couldn't find an SDS layer that corresponds with the aerosol type (or cloud mask). I am wondering if it is possible to plot the aerosol type? If so, are there any resources on how to do this?

For context, I am looking at a small scale region (city level) that has aerosols present but it is unknown the speciation of these aerosols. It would be very helpful to learn if they are dust, smoke, or something else.

https://modis-land.gsfc.nasa.gov/MAIAC.html

Any advice is greatly appreciated! Thanks!

Hi Jennifer,
I believe the aerosol type is in the Status QA SDS layer. Bits 9-10 are referred to as AOD Type. The 3 types are:
00=Background aerosol
01=Smoke
10=Dust
Please see pages 10-12 of the User Guide for more information: https://lpdaac.usgs.gov/documents/1500/MCD19_User_Guide_V61.pdf
Let us know if you have any further questions.
Thanks,
Brett

Hi Brett,

As a follow up question, I noticed that the AOD type QA bits are in MCD19A1 and there is an "Aerosol Model" in MCD19A2 in bits 13-14. Do you know how the aerosol model differs from the aerosol type? Additionally, do you know if the aerosol model can be used to determine what aerosol type is present as well?

Thanks,
Jennifer

Hi Jennifer,
We were able to get the answer straight from the MODIS Science Team, and following is what they said:

"If smoke/dust is tested for a given pixel, these bits will be set. Different AOD types correspond to different AOD model used in the algorithm, we use these terms interchangeably.

So they are actually the same."

Thanks,
Brett

Thank you!