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

From HETEAC to HETEAC-Flex and beyond- algorithm developments
in preparation for EarthCARE
Athena Augusta Floutsi, Holger Baars and Ulla Wandinger
Leibniz Institute for Tropospheric Research (TROPOS), Leipzig, Germany
1Outlineo HETEACo HETEAC-Flex

o Applicationso Summary & Outlook

ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy2Hybrid End-To-End Aerosol Classification
HETEACGoal: Radiation closure for 100 km2 within 10 Wm-2

1. Proper aerosol classification basedon the ATLID observations

Serves as a common baseline for thedevelopment, evaluation andimplementation of EarthCARE algorithms

2. An aerosol model that connects
microphysical, optical, and radiative
properties of predefined aerosol types,
to derive the input parameters forradiative transfer calculations

Synergy between:• ATLID (Atmospheric Lidar)• MSI (Multi-Spectral Imager)• BBR (Broad-Band Radiometer)

Hybrid: theoretical microphysical description fits the experimental findings
End-to-end: uniform representation of the different aerosol types in terms ofmicrophysical, optical and radiative properties
Wandinger et al., 2023
Illingworth et al., 2015
ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy

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HETEAC
Portable Raman lidar systems PollyXT

Aerosol types are composed of basic aerosol components(ESA Climate Change Initiative (CCI)- AERONET probability distribution statistics)

DeLiAn as baseline

smokedustpollution

S = 117.2 sr
δ=0

S = 60.9 sr
δ=0
S = 17.4 sr
δ=0
S = 57.9 sr
δ = 0.25
coarse mode,• Stationary and non-stationaryMixturessites
spherical
Lookup tables• Research vessels• Field campaigns

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

de Leeuw et al., 2013
Floutsi et al., 2023
Holzer-Popp et al., 2013 Wandinger et al., 2023
Baars et al., 2016

4HETEAC
Mixtures of 2 or 3 components

ATLID Target Classification

The joint S–δ distribution for each aerosol type is modeledusing a Gaussian probability distribution defined by a meanlidar ratio, particle linear depolarization ratio, and theirassociated Gaussian widths and correlation.
Wandinger et al., 2023
ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy

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HETEAC – Halifax scene
A-PRO

modeled nadir total extinction field

EC-SIM

A-PRO

EC-SIM

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

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HETEAC- Flex• Based on lidar-derived intensive optical properties• Microphysical properties in accordance with HETEAC• Identification of up to four different aerosol components /quantification of their contribution to the aerosol mixture
in terms of relative volume• Applicable to ground-based and spaceborne lidars• Flexible

Floutsi et al., EGUsphere, in review
ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy

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HETEAC- Flex: flexibility
Retrieval modes
15

δ532, S532
δ355, S355, Å355/532
δ532, S532,Cβ532/1064
δ355, S355, δ532, S532

6

δ355, S355, Å355/532, δ532, S532,Cβ532/1064234

δ: depolarization ratio
S: lidar ratioÅ: Ångström exponent
Cβ: color ratio

Input parametersδ355, S355

Widely applicable
Dif
Minimum requirement two parameters/measurement

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

Lidarconfiguration

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Applications: Saharan dust above Cyprus
20 April 2017
Lidar Ratio
49±8 sr 44±7 sr
Depolarization Ratio
21±2% 26±2%Falcon→Haarig M. et al., Monday, 11:45

0.5-9 km
17:40-19:30 UTCFloutsi et al., EGUsphere, in review
ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy9Summary & Outlook
HETEAC ensures uniform representation of aerosol types and consistency within the EarthCARE
processors• Tropospheric aerosol components are fully covered• HETEAC 2.0 - take into account stratospheric aerosol types such as volcanic ash, sulfates,
stratospheric smoke and polar stratospheric clouds (→ Poster no. 2)

HETEAC – Flex: high flexibility and easily applicable to ground-based lidars within cal/val framework• Quantification of the aerosol mixing state• Microphysical model to be continuously updated

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

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References••
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Wandinger, U., Floutsi, A. A., Baars, H., Haarig, M., Ansmann, A., Hünerbein, A., Docter, N., Donovan, D., van Zadelhoff, G.-J., Mason, S., and Cole, J.: HETEAC – theHybrid End-To-End Aerosol Classification model for EarthCARE, Atmos. Meas. Tech., 16, 2485–2510, https://doi.org/10.5194/amt-16-2485-2023, 2023.
Illingworth, A. J., and Coauthors, 2015: The EarthCARE Satellite: The Next Step Forward in Global Measurements of Clouds, Aerosols, Precipitation, and Radiation. Bull.
Amer. Meteor. Soc., 96, 1311–1332, https://doi.org/10.1175/BAMS-D-12-00227.1.
de Leeuw, G., Holzer-Popp, T., Bevan, S., Davies, W. H., Descloitres, J., Grainger, R. G., Griesfeller, J., Heckel, A., Kinne, S., Klüser, L., Kolmonen, P., Litvinov, P., Martynenko,D., North, P., Ovigneur, B., Pascal, N., Poulsen, C., Ramon, D., Schulz, M., Siddans, R., Sogacheva, L., Tanré, D., Thomas, G. E., Virtanen, T. H., von Hoyningen Huene, W.,Vountas, M., and Pinnock, S.: Evaluation of seven European aerosol optical depth retrieval algorithms for climate analysis, Remote Sens. Environ., 162, 295–315,
https://doi.org/10.1016/j.rse.2013.04.023, 2015.
Holzer-Popp, T., de Leeuw, G., Griesfeller, J., Martynenko, D., Klüser, L., Bevan, S., Davies, W., Ducos, F., Deuzé, J. L., Graigner, R. G., Heckel, A., von Hoyningen-Hüne, W.,Kolmonen, P., Litvinov, P., North, P., Poulsen, C. A., Ramon, D., Siddans, R., Sogacheva, L., Tanre, D., Thomas, G. E., Vountas, M., Descloitres, J., Griesfeller, J., Kinne, S.,Schulz, M., and Pinnock, S.: Aerosol retrieval experiments in the ESA Aerosol_cci project, Atmos. Meas. Tech., 6, 1919–1957, https://doi.org/10.5194/amt-6-1919-2013,
2013
Floutsi, A. A., Baars, H., Engelmann, R., Althausen, D., Ansmann, A., Bohlmann, S., Heese, B., Hofer, J., Kanitz, T., Haarig, M., Ohneiser, K., Radenz, M., Seifert, P., Skupin,A., Yin, Z., Abdullaev, S. F., Komppula, M., Filioglou, M., Giannakaki, E., Stachlewska, I. S., Janicka, L., Bortoli, D., Marinou, E., Amiridis, V., Gialitaki, A., Mamouri, R.-E.,
Barja, B., and Wandinger, U.: DeLiAn – a growing collection of depolarization ratio, lidar ratio and Ångström exponent for different aerosol types and mixtures fromground-based lidar observations, Atmos. Meas. Tech., 16, 2353–2379, https://doi.org/10.5194/amt-16-2353-2023, 2023.
Baars, H., Kanitz, T., Engelmann, R., Althausen, D., Heese, B., Komppula, M., Preißler, J., Tesche, M., Ansmann, A., Wandinger, U., Lim, J.-H., Ahn, J. Y., Stachlewska, I. S.,
Amiridis, V., Marinou, E., Seifert, P., Hofer, J., Skupin, A., Schneider, F., Bohlmann, S., Foth, A., Bley, S., Pfüller, A., Giannakaki, E., Lihavainen, H., Viisanen, Y., Hooda, R. K.,
Pereira, S. N., Bortoli, D., Wagner, F., Mattis, I., Janicka, L., Markowicz, K. M., Achtert, P., Artaxo, P., Pauliquevis, T., Souza, R. A. F., Sharma, V. P., van Zyl, P. G., Beukes, J. P.,
Sun, J., Rohwer, E. G., Deng, R., Mamouri, R.-E., and Zamorano, F.: An overview of the first decade of PollyNET: an emerging network of automated Raman-polarization
lidars for continuous aerosol profiling, Atmos. Chem. Phys., 16, 5111–5137, https://doi.org/10.5194/acp-16-5111-2016, 2016
Floutsi, A. A., Baars, H., and Wandinger, U.: HETEAC-Flex: An optimal estimation method for aerosol typing based on lidar-derived intensive optical properties,
EGUsphere [preprint], https://doi.org/10.5194/egusphere-2023-1880, 2023.

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