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Clarification on the Availability of Total Particulate Optical Depth Parameters in CALIPSO V4.51 Data Products

Posted: Tue Jun 17, 2025 3:25 am America/New_York
by aakashmodis
Hi,
My name is Aakash, and I am currently working on aerosol–cloud interactions. I would like to raise a query regarding the CALIPSO Version 4.51 aerosol product (CAL_LID_L2_05kmAPro-Standard-V4-51).

In the latest version of the CALIPSO aerosol product (CAL_LID_L2_05kmAPro-Standard-V4-51), the Data Quality Statement for the CALIPSO Version 4.51 Lidar Level 2 Data Products (Section 3: Total Column Particulate Optical Depths above Opaque Water Clouds) describes a new approach to estimate total column particulate optical depth at 532 nm above opaque water clouds. The document further states that this new column optical depth and its associated uncertainty are included in the V4.51 CALIOP Layer Level 2 data product, and notes that these parameters are labeled as "particulate" and do not differentiate by feature type, unlike other column optical depth parameters.


However, upon reviewing the available product descriptions for both the APro-V4.51
(https://www-calipso.larc.nasa.gov/resources/calipso_users_guide/data_desc/cal_lid_l2_profile_v4-51_desc.php) and VFM-V4.51
(https://www-calipso.larc.nasa.gov/resources/calipso_users_guide/data_desc/cal_lid_l2_vfm_v4-51_desc.php), no SDS explicitly corresponding to this newly introduced total column particulate optical depth or its uncertainty could be identified.

Clarification is requested regarding the presence and identification of this parameter in the current V4.51 CALIOP Level 2 data products—specifically, the name(s) of the relevant SDS(s) and the product(s) in which they are included.

Re: Clarification on the Availability of Total Particulate Optical Depth Parameters in CALIPSO V4.51 Data Products

Posted: Wed Jun 18, 2025 7:30 am America/New_York
by ASDC - cheyenne.e.land
Hello,

Yes, that is correct this parameter is included in the V4.51 CALIOP Layer Level 2 data products not the V4.51 CALIOP Profile Level 2 data products.

Here is the list of the Layer Level 2 data products (the latest version) and the link to the Product Description:
CAL_LID_L2_01kmCLay-Standard-V4-51
CAL_LID_L2_05kmALay-Standard-V4-51
CAL_LID_L2_05kmCLay-Standard-V4-51
CAL_LID_L2_05kmMLay-Standard-V4-51
CAL_LID_L2_333mMLay-Standard-V4-51
Version 4.51 Level 2 Layer Products Description

Thanks,
ASDC

Re: Clarification on the Availability of Total Particulate Optical Depth Parameters in CALIPSO V4.51 Data Products

Posted: Fri Jun 27, 2025 1:53 am America/New_York
by aakashmodis
Thank you for the clarification and for sharing the list, this distinction between profile and layer products is appreciated.