Publications

Choudhury, G; Tesche, M (2022). Assessment of CALIOP-Derived CCN Concentrations by In Situ Surface Measurements. REMOTE SENSING, 14(14), 3342.

Abstract
The satellite-based cloud condensation nuclei (CCN) proxies used to quantify the aerosol-cloud interactions (ACIs) are column integrated and do not guarantee the vertical co-location of aerosols and clouds. This has encouraged the use of height-resolved measurements of spaceborne lidars for ACI studies and led to advancements in lidar-based CCN retrieval algorithms. In this study, we present a comparison between the number concentration of CCN (n(CCN)) derived from ground-based in situ and spaceborne lidar cloud-aerosol lidar with orthogonal polarization (CALIOP) measurements. On analysing their monthly time series, we found that about 88% of CALIOP n(CCN) estimates remained within a factor of 1.5 of the in situ measurements. Overall, the CALIOP estimates of monthly n(CCN) were in good agreement with the in situ measurements with a normalized mean error of 71%, normalized mean bias of 39% and correlation coefficient of 0.68. Based on our comparison results, we point out the necessary measures that should be considered for global n(CCN) retrieval. Our results show the competence of CALIOP in compiling a global height- and type-resolved n(CCN) dataset for use in ACI studies.

DOI:
10.3390/rs14143342

ISSN:
2072-4292