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

Validation of EarthCARE’s aerosol model HETEAC
with airborne in-situ observations
Moritz Haarig1, Athena Floutsi1, Holger Baars1, Ulla Wandinger1, Bernadett Weinzierl2, Maximilian Dollner2, ManuelSchöberl2, Aryasree Sudharaj3, Konrad Kandler3, Rodanthi Mamouri4
1 Leibniz Institute for Tropospheric Research, Leipzig, Germany
3 Technische Universität Darmstadt, Darmstadt, Germany

2 Universität Wien, Aerosolphysik und Umweltphysik, Vienna, Austria
4 Eratosthenes Centre of Excellence, Limassol, Cyprus

HETEAC-Flex Validation
HETEAC (Look-Up Tables at 355 nm)→ HETEAC-Flex (Optimal Estimation at 355, 532 and 1064 nm)
introduced in previous talk by Athena Floutsi(Floutsi et al., in discussion 2023)

Do we get the correct microphysical properties
under complex aerosol mixtures?
Correct typing?

Correct microphysics?

HETEAC-Flex

effective diameter Deff
refractive index mR & mI

Microphysical propertiesof mixtures
HETEAC: Aerosol model behind all calculations inEarthCARE processors (Wandinger et al., 2023)

Compare to airborne
in-situ observations

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

Defined by pure types

Cyprus – Complex aerosol mixtures

Cyprus

A-LIFE campaign• April 2017
• ERC grant of B. Weinzierl• Additional funding from
ESA for HETEAC Validation

In situ (air)Aircraft in-situ• size distr.
• refractive index

Remote sensing (ground)
Lidar (3 bsc. + 2 ext. + 2 depol.)Cloud radarRadiation
ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy

3555321064

10 Cases for comparison
Fine Spherical
Absorbing (FSA)
Deff = 0.28 µm
mR = 1.50mI = 0.043

3975

Fine Spherical NonAbsorbing (FSNA)
Deff = 0.28 µm
mR = 1.45mI = 0.001

Coarse NonSpherical (CNS)
Deff = 3.88 µm
mR = 1.54mI = 0.006

46 12108no statisticallysignificant solutions

Fine mode
Optical properties for
HETEAC-Flex do slightly
differ from HETEAC

Coarse Spherical(CS)Deff = 3.88 µm
mR = 1.37mI = 4e-8
Coarse mode

Rarely pure cases → Complex mixtures in the Eastern Med.

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

Floutsi et al., 2023
Wandinger et al., 2023

Dust-dominated case 21 April 2017

Compareswithinuncertainty

Corse non-spherical(“dust”)

Deff

Optical Properties at 3.4 – 6.0 km height (355, 532 nm)
Lidar Ratio (sr)60 ± 951 ± 8Depolarization Ratio
25 ± 2%28 ± 2%HETEAC-Flex

Saharan Dust Outbreak
20–22 April

Refractive Index(Preliminary)Real part
Imaginary part

HETEAC_flex
1.534 ± 0.008
0.0057 ± 0.0013
355 nmESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italyin-situ
1.58
0.0111550 nm
370 nmNon-dust-dominated case 11 April 2017
Fine strongly absorbing(“smoke”)

DeffGood
agreement

FalconOptical Properties at 1.2 – 1.5 km height (355, 532 nm)
Lidar Ratio (sr)67 ± 1366 ± 32
Depolarization Ratio
12 ± 2%4.5 ± 2%HETEAC-Flex

Polluted PBL

Refractive Index(Preliminary)Real part
Imaginary part

HETEAC_flex
1.497 ± 0.010
0.032 ± 0.004
355 nmESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italyin-situ
1.61
0.049
550 nm
370 nmRefractive Index Comparison (preliminary)in situ: Offline analysis of filter samples at TU Darmstadt
Real part

Imaginary partof AODof AOD

Di Biagio et al., 2019
Dust (all deserts)

Di Biagio et al., 2019Dust (all deserts)

Underestimation by HETEAC-Flex compared to filter sample analysis
HETEAC-Flex based on previous observations (maximum value of mR = 1.54)
ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy

Preliminary comparison
Maybe more absorbing aerosol andpolluted dust in Eastern Mediterranean?

Effective Diameter Comparison
in situ: combination of several instruments (10 nm – 50 µm) of University of Vienna• If a statistically significant solution was found:Good agreement for dust-dominated and nondust-dominated cases
21 April

HETEAC max• Single events of large particles are not covered• All cases represent (complex) mixtures ofaerosol components→ Confidence that HETEAC-Flex provides good
estimates of effective diameter< 55% dust
11 April

HETEAC min

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

Conclusion
HETEAC-Flex• is available for EarthCARE validation (Floutsi et al., 2023 in discussion)• uses 4 aerosol components with prescribed propertiesto derive the microphysical properties of aerosol mixtures• effective diameter is in good agreement with airborne in situ observations• work on refractive index comparison is ongoing
Lidar + airborne in situ is important source of information to validate retrievals• In-situ observations should cover full size range (≈10 nm – 50 µm)• A-LIFE provided good comparisons in complex mixtures• We are open to include further data sets (lidar + in-situ), e.g., from ACTIVATE
We acknowledge funding from ESA for the A-CARE project (ESA RFP 3-15303/18/NL/CT/gp)
ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy