Earthdata Forum

Hello again,

I have a question regarding some of my observations using the L3 CALIOP tropospheric profile all-sky dataset, V4.20/21. In reading about the V4 scene classification algorithm (https://amt.copernicus.org/articles/11/ ... 7-2018.pdf) it seems like it should be impossible for the SCA to type an aerosol as "elevated smoke" if it occurs below 2.5 km, and impossible for a layer to be typed as "polluted continental" if it occurs above 2.5 km. However, when plotting vertical profiles of the extinction coefficients for different aerosol types, I see that in some areas (e.g., Eastern China) there can be extinction coefficients as high as ~.03 km^-1 for elevated smoke that occur below the 2.5 km threshold.

I am not sure if there are more recent updates to the SCA than were mentioned in the 2018 Kim et al paper, but I was wondering if someone could help reconcile this observation with what I'm reading about the SCA.

Thanks in advance for any insight you can provide!

Thank you for your question. A Subject Matter Expert has been notified and will answer your question shortly. Please stand by!

Hi there,

I answered my own question by realizing that it is only the top of the layer has to be above the 2.5 km threshold for the SCA to classify the entire layer as elevated smoke, which is why there is elevated smoke below 2.5 km. Thank you for your help!

Best,

Sarah

Hi Sarah,

You are exactly right. Because the layer top altitude is evaluated to determine when smoke is injected above 2.5 km (a rough approximation for the boundary layer), it is possible for the lower portion of these smoke layers to exist below 2.5 km.

Best regards,
Jason Tackett