Comparison of AOD from CALIPSO, MODIS, and Sun Photometer under Different Conditions over Central China

Boming Liu,Ming Zhang,Yifan Shi,Wei Gong,Wei Wang,Yingying Ma

doi:10.1038/s41598-018-28417-7

Abstract

Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) provides three-dimensional information on aerosol optical properties across the globe. However, the performance of CALIPSO aerosol optical depth (AOD) products under different air quality conditions remains unclear. In this research, three years of CALIPSO level 2 AOD data (November 2013 to December 2017) were employed to compare with the Moderate Resolution Imaging Spectroradiometer (MODIS) level 2 columnar AOD products and ground-based sun photometer measurements for the same time period. To investigate the effect of air quality on AODs retrieved from CALIPSO, the AODs obtained from CALIPSO, MODIS, and sun photometer were inter-compared under different air quality conditions over Wuhan and Dengfeng. The average absolute bias of AOD between CALIPSO and sun photometer was 0.22 ± 0.21, 0.11 ± 0.07, and 0.14 ± 0.13 under clean, moderate, and polluted weather, respectively. The result indicates that the CALIPSO AOD were more reliable under moderate and polluted days. Moreover, the deviation of AOD between CALIPSO and sun photometer was largest (0.23 ± 0.21) in the autumn season, and lowest (0.13 ± 0.12) in the winter season. The results show that CALIPSO AOD products were more applicable to regions and seasons with high aerosol concentrations.

Highlights

Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) observations over most regions[20]
This indicates that the aerosol optical depth (AOD) obtained from CALIPSO and Moderate Resolution Imaging Spectroradiometer (MODIS) have good correlation with the ground-based observations
To investigate the effect of air quality on AODs retrieved from CALIPSO, the AODs obtained from CALIPSO, MODIS, and sun photometer were compared under different air quality conditions

Summary

Introduction

Liu et al evaluated the performance of CALIPSO AOD products on the high-value regions and low-value regions, and studied the seasonal variation of AOD products over China[21]. Such comparisons provide valuable insights into the application of CALIPSO products. There are still few studies evaluating CALIPSO AODs under different air quality conditions. The effect of air quality on CALIPSO AOD inversion needs further research, which is important for the application of CALIPSO AODs in regional environmental research. When taking into consideration the effect of air quality on CALIPSO AOD inversion, we find that concentrations of fine particulate matter (PM2.5) play an important role in the consistency of comparisons. Differences in AOD between CALIPSO and sun photometer measurements have obvious seasonal characteristics

Results

Discussion

Conclusion