ESA-JAXA Pre-Launch EarthCARE
Science and Validation Workshop
13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), ItalyAerosol observation using ATLID and CALIOPand its application
Nishizawa, T.(1), Kudo R.(2), Oikawa E.(2), Higurashi A.(1), Jin Y.(1), and Okamoto H.(3)(1) NIES, Japan, (2) JMA/MRI, Japan, (3) Kyushu University, Japan

EarthCARE(Earth Clouds, Aerosols and Radiation Explorer)✓ Joint Japanese (JAXA)-European (ESA) satellite mission✓ Improve the understanding of cloud-aerosol-radiation interactions✓ Four sensors:
ATLID (Atmospheric Lidar: 355nm HSRL with dep. Measurement function)
MSI (Multi-spectral imager: 0.66, 0.865, 1.61, 2.2, 8.8, 10.8, 12.0 um)
CPR (Cloud Profiling Radar: 94GHz)
BBR (Broad-band radiometer: SW (0.2-4um), Total (0.2-50um)=> Observe Global / 3D distribution of clouds and aerosols and Radiation=> Provide information on Cloud and Aerosol effects on atmospheric radiation
Cloud and precipitation• Optical / Microphysical / Radiative properties : Extinction, Size distribution, Single scattering albedo, etc…
• Particle type: Water, Ice, Mixed, snow, drizzle, etc…
Aerosols• Optical / Microphysical / Radiative properties• Particle type: CALIOP / AERONET / EARLINET: Biomass burning, Marine, Smoke, etc…
• Component: Aerosol transport model / NIES: Dust, Sea-salt, black carbon, Water soluble, etc…
ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy

JAXA L2 ATLID & ATLID-MSI algorithm flow

MOP: Molecular optical property
COP/AOP: Cloud/Aerosol optical property
FM: Feature mask
TM: Target mask
PBL: Planetary boundary layer
QF: Quality flag(0.3)(1)(1*): Horizontal resolution [km]
ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy

Application to Joint-Simulator data (Signal)
Algorithm flow

ECA_J_ATL_CLA_2AS_20080619T0040_20080619T0051_60002A_vAa
ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy

Application to Joint-Simulator data (FM)
Applying the threshold method developed based on the Kyushu University method[Okamoto et al. 2008,2010, Hagihara et al. 2010]

Correct rates for Aerosol, Cloud, Total > 90%
ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy

Algorithm flow

ΔH=10km, ΔZ=0.1km
ECA_J_ATL_CLA_2AS_20080619T0040_20080619T0
051_60002A_vAa

Application to Joint-Simulator data (AOP, COP)
ΔExtinction, ΔBackscatter, ΔDepolarization ~ 30% or less (excluding edge area)

Algorithm flow

MethodOptimization by using Gauss-Newton method with
Biconjugate gradient method [Kudo et al. 2016]
A priori constrains
・Vertical and Horizontal smoothness
・A priori value for lidar ratio with lagrange
multiplier depending on the extinction
coefficient.

ΔH=10km, ΔZ=0.1km
Data=ECA_J_ATL_CLA_20080619T0005-600001F
ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy

Application to Joint-Simulator data (PBLH)
Algorithm flow

✔︎ Retrieve PBLH using Wavelet Covariance Transform (WCT)✔︎ Bias = -0.01 km, RMSE = 0.34 km
Particle extinction (ΔH=10km)

Retrieved PBL height

True

Retrieval

Error

ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy

Retrieval Procedure
1. Calculate backscattering ratio – 1 byMie att. backscatter / Rayleigh att.
backscatter from L1b data
2. Normalize BR – 1 to 1.0 for the first 1
km height from the surface elevation
3. Calculate wavelet covariancetransform (WCT) for the normalized
BR – 1 with Haar function (1 kmwindow)
4. PBL height is determined whenexceeding a threshold (0.2) andhaving the maximum WCT
ΔH=10km, ΔZ=0.1km
ECA_J_ATL_CLA_2AS_20080619T0040_20080619T005
1_60002A_vAa

Application to Joint-Simulator data (TM/aerosol)

The algorithm performance is being investigated.
ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy

Research Products-- Aerosol retrieval using CALIOP+MODIS -Algorithm flow

Details are inKudo et al. AMT, 2023

Retrieved parameters✓Extinction coefficients for water-soluble, Sea-salt, Dust, Light-absorbing particle✓Columnar-mean fine-mode and coarse-mode radii
ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy

Research Products-- Long term trend in 2007-2021-Remarkably decreasing trend of AOD was found in East and West Asia,
which is consistent with the other studies (e.g., Pollutant emission data and dust observation date by meteorological observation).

*Green contour
indicates
statisticallysignificant trend
determined by ttest.
ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy

Summary
We have developed aerosol and cloud retrieval algorithms using the EarthCARE satellite onboard lidar and imager.
1) Apply the algorithm to Joint-simulator and evaluating its overall performance.
2) Feature mask
Introduce the threshold method based on the Kyushu University method(discrimination of noise, atmospheric molecules, aerosols, and clouds).
3) Particle optical properties (POP product)
Retrieve extinction/backscatter/dep by Maximum Likelihood Estimation (MLE).
4) Aerosol type identification (target mask)
Develop the threshold values and models using ground-based lidar + passive sensor data.
The algorithm performance is under investigation.
5) Aerosol component analysis (CALIOP/MODIS analysis)
・Long-term data analysis from 2007 to 2021 was conducted, and we found the remarkable trend in East Asia andWest Asia.
・Data assimilation experiments using the NICAM-Chem model are underway.
=> These studies can be extended to EarthCARE data.

ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy