Details of Validation with other satellite data Details of Validation with in-situ data
Product：
Aerosol Property - Aerosol Optical Thickness (ARP-AOT)
- L2 (Ver. 3.1)
- L3 hourly (Ver. 3.1)
5km spatial resolution
Validation data:
Terra and Aqua MODIS aerosol product (MOD04,MYD04 L2)
10km spatial resolution
- Land: AOT at 0.5 micron interpolated from AOTs at 0.47 micron and 0.55 micron of
"15. Corrected_Optical_Depth_Land" by logarithminc interpolation
-Sea: AOT at 0.5 micron interpolated from AOTs at 0.47 micron and 0.55
micron of "35. Effective_Optical_Depth_Best_Ocean" by logarithminc interpolation
Comparison conditions:
- Temporal Condition: The latest Himawari-9 AOT data within +/- 5 min from
the observation time of MODIS.
- Spatial Condition: The average of the nearest 4 pixels of Himawari-9 AOT
data to the center of a pixel of MODIS data
Data screening:
- Cloud flag of Himawari-9 AOT = clear, additional cloud test = clear
(QA_flag bit8 = 0)
- Himawari-9 AOT is valid (AOT != -32768.0)
- AOT ranging from 0 to 2 for both Himawari-9 and MODIS
Definition:
- Bias = Himawari-9 AOT - MODIS AOT
The graphs shown:
(a) Monthly scatter plot
(b) Monthly scatter plot (confidence = very good or good)
(c) Bias and RMSE assuming Aqua/MODIS AOT as a basis
(d) Bias and RMSE assuming Terra/MODIS AOT as a basis
(e) Bias and RMSE assuming Terra and Aqua MODIS AOT as bases
Product：
ARP L2 (Ver. 3.1), L3 hourly (Ver. 3.1)
Methodology：
Matchup comparison with AERONET(Version 3; AOD Level 2.0) and SKYNET(Retrieved by Hitoshi Irie; CEReS, Chiba University)
Data used：
- AHI ARP L2 (5km resolution) AOT（Aerosol optical thickness）、AE（Angstrom exponent）、SSA（Single scattering albedo）
- AHI ARP L3 hourly (5km resolution) AOT、AE
Comparison conditions：
- Temporal condition ：The Closest AHI data from the observaion site of AERONET and SKYNET.
- Spatial condition ：The nearest AHI data from the observation site of AERONET and SKYNET.
- Wavelength condition：Matchup ARP property at 500 nm for both AHI and Field observation data（AERONET and SKYNET）.
However, AOT at 500 nm is estimated from AOT at x(440~675) nm using AE in the case AOT at 500 nm is not observed for AERONET.
The Estimation formula is bellow.
Data screening：
- AHI ARP L2：
cloud flag= clear, additional cloud test = clear (QA_flag bit2 = 0 and bit8 = 0)
AHI data is valid.
- AHI ARP L3：
cloud flag= clear, additional cloud test = clear (QA_flag bit2 = 0 and bit8 = 0)
AHI data is valid.
Drawing conditions：
- Drawing range is 0.0 <= AOT <= 2.0、-0.5 <= AE <= 2.0、0.5 <= SSA <= 1.0 for both AHI and Field observation data（AERONET and SKYNET）.
- Both frequency and statistics are calculated only for data included in the Drawing range.
The graphs shown：
(a) Monthly scatter plot
Acknowledgement:
- We thank the PIs, Co-Is, and their staff for establishing and maintaining the AERONET and SKYNET sites used in this investigation.