Clouds and climate transitioning
to post-fossil aerosol regime:
CleanCloud
Ulas Im1, Athanasios Nenes2,3, Ulla Wandinger4,
Holger Baars4, Otto Hasekamp5, Bastiaan vanDiedenhoven5, Johannes Quaas6, Philip Stier7, Patric
Seifert4, and the CleanCloud consortium
ESA-JAXA Pre-Launch EarthCARE Workshop
ESA-ESRIN, Frascati, 13 November 2023
1AU, DK 2FORTH,GR 3EPFL, CH 4TROPOS, DE5SRON,NL 6ULei, DE 7UOXF, UKCONSORTIUM• Lead Coor. AU (DK), Sci. Coor. FORTH (GR)• 14 EU partners + 4 UK partners + 2 CH partners• Start date: 1 January 2024
• Collaboration with ACTRIS, ESA, NASA• Hajime Okamoto (JAXA): Advisory Board

ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop

OBJECTIVES
CleanCloud will
• carry out targeted field experiments in European climate hotspots• develop state-of-the-art algorithms to obtain new proxies and diagnostics for key ACIrelated processes• contribute to the calibration and validation of upcoming satellite missions• improve and better constrain kilometer- and large-scale climate models using
advanced machine learning, data assimilation and model calibration• assess the role of aerosols in the life cycle of convective systems and extreme events

ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop

Build over 3
scientific clusters
1) Process
understading
2) Convective lifecycle
3) Predictions &Projections

A. BIG DATA

C. ASSESSMENT

B. MODEL
DEVELOPMENTMETABASE
OBSERVATIONALPARAMETERIZATIONSPROCESS
PARAMETERIZATIONSMODEL ANALYSESCONVECTIVE
LIFECYCLEDATA CENTRESKMSCALE
EXISTING &UPCOMINGCAMPAIGNS
CleanCloud
EXPERIMENTS&RETRIEAVALSJOINT MISSIONSLARGESCALEDATAANALYSESPROCESSUNDERSTANDING

OBSERVATIONALCONSTRAINTS

LIFECYCLEASSESSMENT

MACHINELEARNINGLESEMULATORAEROSOL
LIFECYCLEADVANCEDKNOWLEDGEPERTURBED PARAMETERENSEMBLE
LARGE EDDYSIMULATORS (LES)

ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop

CLIMATEPROJECTIONS

D. SYNTHESISACI PROCESSESRADIATIVEFORCING
CLIMATEASSESSMENTS

Use of EarthCARE in CleanCloud• Field closure experiments todevelop new retreival algorithms• Use these new algorithms inEarthCARE Cal/Val activities• Use new retriavals in creating
PPEs in km-scale and large-scaleclimate models

LES/KMSCALE:CICERO,CNRS, ETHZ,FMI, FORTH,GUF, UELI,UOXF, UKMO

IN-SITU: AU,CNR, CYI,EPFL, ETHZ,FORTH,NCRS-D, SU
LAND-BASEDREMOTESENSING:EPFL,
FORTH,TROPOSACI
ESM: AU,CICERO,CNRS, ETHZ,FMI, FORTH,KIT, TROPOS,UREAD,UNEXESATELLITE:
SRON,TROPOS,ULEI, UOXFCHAMBER:AU, FORTH,SUESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop

FIELD CAMPAIGNS• Arctic (Villum: Spring & Summer 2024)• Mediterranean: Mt. Helmos (Autumn 2024)• HALO-South & ATTO (TROPOS)
ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop

CLOSURE EXPERIMENTS & NEW ALGORITHMS➢ Develop new satellite retrieval
algorithms that focus on
determining the processes activein mixed-phase clouds, i.e. SIP:
rime splintering, droplet
shattering and ice-ice collisions.

ESA
EartCARE

ARCSIX
Aircraft
UAVs➢ ACTRIS sites with lidar
and cloud radar➢ HALO-South➢ ATTO

Helikite

WindLidar

CloudRadar

Aerosol
Lidar➢ Improve existing algorithms forretrieving droplet number andIn-situ
ice crystal number concentrationin both liquid-and mixed-phase
Surfaceclouds.

Monitoring

ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop➢ NASA PACE

➢ Cal/Val activities

MODEL CONSTRAINTS• Perturbed Parameter
Ensemble (PPE)s for
km-scale climate
models:• ICON-HAM-Lite• ICON-HAM• EC-Earth• Aerosols• Clouds

Johnson et al., ACP, 2018

MODEL CONSTRAINTS
Better proxies for CCN (e.g.
aerosol water content and drysize distribution):➢ Aerosol absorption,➢ Aerosol number,➢ Aerosol concentration,➢ Aerosol size distribution➢ Aerosol refractive index

Cloud-base aerosolconcentrations and typeusing vertical profiles:➢ Aerosol extinction,➢ Aerosol backscatter,➢ Aerosol depolarization

Vertical profiles and uncertainty:➢ Cloud phase,➢ Ice water content,➢ Vertical motions,➢ precipitation rates,➢ particle size,➢ aerosol extinction

SUMMARY• What CleanCloud can offer to EarthCARE:• New datasets for Cal/Val• New proxies for CCN, INPs, vertical velocity, and cloud processes• New remote sensing retreival algorithms• What EarthCARE can offer to CleanCloud:• Improved aerosol and cloud products• Better proxies for CCN, INP, etc• Vertical profiles

Model constraints• Repository for non-ACTRIS datasets?
• Postdocs and graduate students to carry out research for CleanCloud.

THANK YOU !

Ulas Im: ulas@envs.au.dk
Athanasios Nenes: athanasios.nenes@epfl.chPlease follow us on Twitter/X: @CleanCloud_HE
ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop