It is quite possible. Just as Muhammed Eltahan

I hope this is helpful?

Hi...you can try with NASA's AERONET website for regional AOD data,

https://aeronet.gsfc.nasa.gov/

Thank you all for your answers.

Clarify which data source your are looking for? I mean to ask whether ground-based measurements or satellite retrievals. You can download the Level 2 satellite (e.g., MODIS, MISR, OMI) data products for scientific purpose.

Useful and interactive links to download AOD data:

Giovanni

https://giovanni.gsfc.nasa.gov/giovanni/

LAADS​

https://ladsweb.modaps.eosdis.nasa.gov/

You can use MODIS, VIIRS, MERRA-2. Take into account the data level, and the resolutions: temporal, spatial, radiometric, and spectral.

Also, it could be interesting the analysis of the vertical profile to understand the aerosol type using an active sensor:

https://eosweb.larc.nasa.gov/project/calipso/calipso_table

You can use multiple satellite-based observational databases.

So, you can try at the following links, but not only;

https://ladsweb.modaps.eosdis.nasa.gov/search/

https://worldview.earthdata.nasa.gov/

https://search.earthdata.nasa.gov/search/granules?p=C1443533440-LAADS&tl=1522059331!4!!&fst0=Atmosphere&fsm0=Aerosols

Hope this can help you.

Thanks Juan and Florian

I agree with Juan, is the more practical way to proceed

You may choose different sources to download AOD data.

https://www.researchgate.net/deref/https%3A%2F%2Fgiovanni.gsfc.nasa.gov%2Fgiovanni%2F

https://www.researchgate.net/deref/https%3A%2F%2Fladsweb.modaps.eosdis.nasa.gov%2Fsearch%2F

https://www.researchgate.net/deref/https%3A%2F%2Faeronet.gsfc.nasa.gov%2F

These are satellite-based and ground-based observations.

https://ladsweb.modaps.eosdis.nasa.gov/search/order

You can order MOD04_L2 which is at 10km resolution (not gridded) and MOD04_3K which is at 3km swath product for MODIS Terra. Similarly, MODIS Aqua product (MYD). So that you will have AOD at 10:30am and 13:30 in a day. You can also look into other modis products (MISR) etc

Hello Sir, I am looking for VIIRS AOD data with Aerosol Optical Depth at 550 and with best estimate. this data is available but after downloading that opens in 1x1 and I need that at 6x6 km. How to get that particular data from Earthdata?

I agree, It depends on what AOD data you are looking at. There are many data sources, depending on region, spatial and temporal scale, methodology, etc.

If I need AOD monthly or seasonal average say over North America, what product should I order ?

Thanks in advance