Calibration of global MODIS cloud amount using CALIOP cloud profiles

Kotarba, Andrzej Z.

doi:https://doi.org/10.5194/amt-13-4995-2020

Articles | Volume 13, issue 9

https://doi.org/10.5194/amt-13-4995-2020

© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/amt-13-4995-2020

© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 13, issue 9

Research article

|

25 Sep 2020

Research article |

| 25 Sep 2020

Calibration of global MODIS cloud amount using CALIOP cloud profiles

Andrzej Z. Kotarba

Supplement

https://doi.org/10.5194/amt-13-4995-2020-supplement

Data sets

CALIPSO Lidar Level 2 1km cloud layer data NASA ASDC (Atmospheric Science Data Center) https://doi.org/10.5067/CALIOP/CALIPSO/LID_L2_01KMCLAYSTANDARD-V4-20

MYD35_L2 - MODIS/Aqua Cloud Mask and Spectral Test Results 5-Min L2 Swath 250m and 1km, MODIS Atmosphere L2 Cloud Mask Product S. Ackerman, R. Frey, K. Kathleen Strabala, Y. Liu, L. Gumley, B. Baum, and P. Menzel https://doi.org/10.5067/MODIS/MYD35_L2.061

MYD03 – Geolocation – 1km, MODIS Geolocation Fields Product MCST (MODIS Characterization Support Team) https://doi.org/10.5067/MODIS/MOD03.061

Short summary

This paper evaluates the operational approach for producing global (Level 3) cloud amount based on MODIS cloud masks (Level 2). Using CALIPSO we calculate the actual cloud fractions for each cloud mask category, which are 21.5 %, 27.7 %, 66.6 %, and 94.7 % instead of assumed 0 %, 0 %, 100 %, and 100 %. Consequently we find the operational procedure unreliable, especially on a regional/local scale. A method of how to correct and calibrate MODIS global data using CALIPSO detections is suggested.