Overview of planed Cal/Val activities for
EARTHCARE cloud and precipitation products
Eleni Marinou (ΝΟΑ) on behalf of the Cal/Val teams
2nd ESA EarthCARE Validation Workshop
25-28 May 2021 (online)
ESA UNCLASSIFIED – For ESA Official Use Only

1Overview• Global coverage of Cal/Val teams:• Ground-based stations• Ground-based mobile platforms• Complementary observations• After-Launch field campaigns• QA/QC & calibration practices• Validation strategies and approaches2EarthCARE Ground-based Cal/Val stations
Ground based Lidar stations (>100)
Ground based Radar stations (42)

Radar stations
Europe: 24 + FMI C-band network
North America: 5 + NEXRAD + ARM?
Asia: 4Latin America:2
Antarctica: 3
Atlantic ocean: 2

Additional dense networks:•
NEXRAD network (USA)•FMI C-band radar network (all Finland)•EUMETNET/E-Profile (Europe)
Additional stations under development:•
7 Radars :•Pangea, Antikythera, Greece (NOA)•Lutjewad, The Netherland (land-sea interface) (Apituley)•Melpitz, Germany (>2023) (Baars & Seifert)•Mindelo, Cape Verde (Baars & Seifert)•Xilinhot, North China (CMA; HU)•+ Radars in Dunhuang & Beijing, China (CMA; HU)•8 Lidars :•Lutjewad, The Netherland (land-sea interface) (Apituley)•Amsterdam Island, Indian Ocean (2022) (ACTRIS-FR)•
Lamto, Ivory Coast (2022) (ACTRIS-FR)•
Chacaltaya, Bolivia (2022) (ACTRIS-FR)•
LOA-Lille, France (end of 2023) (ACTRIS-FR)•Maïdo - La Réunion (end of 2023) (ACTRIS-FR)•French Polar-Pod fleet from 2023-2025 around theAntarctica (ACTRIS-FR)•Lijiang Observatory, China (CMA; HU)
2 Moved stations:•Ikaalinen radar (few hundreds km) (FMI)•Lidar station in Dakar city (moved from M’Bour Center)(ACTRIS-FR)
1 Unsecure station:•Korean lidar station (Müller)3

+ Ground-based Mobile Platforms and Systems
Ground based Lidar stations
Ground based Radar stations

Radar stations
Europe: 24 + FMI C-band network
North America: 5 + NEXRAD + ARM?
Asia: 4Latin America:2
Antarctica: 3
Atlantic ocean: 2

2 Radars & Lidars- LACROS (Cloud radar, MWL lidar, BSRN station, MWR)
(TROPOS)- BALI system (Scanning Basta + ulidar 532/808nm)(LATMOS)
2 Multi-WL Radars- Synergistic Poldirad + BASTA (C-band + W-band) (DLR& LATMOS)- SAPHERALER (W+X radars) onboard CNES Balloon(CNES) [first flights 2023 – 2024]
2 Radars- BASTA radars (W-band) network plus highly portablesystem (LATMOS)- X-band on trailer (NOA)
4 Lidars- OCEANET (MWL Lidar, sky camera, MWR,sunphotometers) (TROPOS)- MAMS Mobile Aerosols Monitoring System (automaticlidar, photometers) (ACTRIS- FR)- Aerosol platform (MWL Lidar & sunphotometer) (NOA)- EVE lidar system (ESA)
3 Drones & Balloons- Drones with aerosol and cloud in-situ instruments(Andøya Space AS)- Balloons of in-situ cloud instruments (IRF; Voelger)- UAV/Ballons with aerosol and cloud in-situ
instruments (effective radius, refractive index..) (CyI)
4++

Complementary observations
CR +
MWR+
Distrometer

CR + MWR+
Radiation+
MRR

All Cloudnet stations

German consortium
Cyprus (TROPOS)
Greece (NOA)

ItalyCR+(Lampedusa)
MWR+
Distrometer+C-bandFinland (FMI) 2 stations+S-band

NEXRAD (USA)MWR+
X-band+155 meteor.
stations

WEGN (Austria)

A low altitudegeostationaryzeppelin withcloud radar(LATMOS)

CR+MWR+ Distrometer The Netherland (KNMI) + S-band+ C/X-band Italy (CNR-ISAC)
Greece (NOA)+Radiation+ in-situ
5Planed/proposed field campaigns & targeted products
4 Planed campaigns from LATMOS & DLR & FAAM: target toevaluate all cloud & precipitations products.
- DLR (HALO): CR, MWR, HSRL, SpecMACS- LATMOS (ATR42): multi-beam CR, HSRL- FAAM: lidar, in-situ A&C, MWR, ISMAR radiometer
CCREST (Oct 2023-March 2024): FAAM / DLR F20
TOOC and ECVAL (summer/fall 2024): HALO RS & in-situ
NAWDIC (2025): HALO (+ ATR42)ASCCI and HALO-South (2025): HALO RS & in-situ+ At hoc FAAM flights compatible with other experiments(Summer 2023; Winter 2023/2024): + Chilbloton radar +Satellites + Models: Scene classification and other aerosol &cloud products
LPC2E-CNRS: Balloon-borne measurements: optical counters,
backscatter sonde and lidar: Concentrations in 19 size classes[0.2,100μm] & estimate the main nature of the particles (liquid,ice particles, aerosols) (Winter 2023-2024: France to Equator at
16 - 20 km alt; alternative sites: Canada, Sweden)

6Planed/proposed field campaigns & targeted products
Andoya Space Center: air-borne soundings of A&C, in-situ(Nevzorov probe), aerosol and cloud properties and water vapor,to validate cloud properties (type and phase and opticalproperties) +open for cooperation in international campaigns
JPL: air-borne flights with precipitation and cloud Radar 3-rd
generation (APR-3, Ku-/Ka-/W-band and mechanically scanning
Doppler radar) for microphysical and dynamical retrievals ofclouds.
ECCC (Canada): Airborne & ground-based CR, Lidar + surface
based instruments (droplet size distribution, precipitation,ice/frost, fog) to validate ice cloud retrieval algorithms for polarnight conditions
IRF (Sweden): ground-based lidar + in-situ balloon meas. ofcirrus for validation of cloud products on statistical approach.
INESA (USA): aircraft meas. of ice morphology, ice size
distributions, convective ascent + simulations of storm to study
the mechanisms effecting intensity and microphysicalproperties of deep convective storms.
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QA/QC & calibration practices
QA/QC:• All instruments part of networks apply the network’s QA/QC and unified processing chains:
Cloudnet, Earlinet, ACTRIS, BSRN, AERONET, CRCS.
• Airborne instrumentation: specific QC• FMI weather radars: monitored and calibrated using standard FMI procedures• Some groups have experience from GPM mission: will follow same QA• Few PI/teams: No common/absolute QA procedures
Italy (Lampedusa)
For calibrations:• Cloudnet radars: calibrated with absolute calibration of reference DCR or regular calibrationtransferring several radars in the same site for calibration (additional use of UAV targets).
• K-band calibrated for precipitation using a combination of instruments including an X-band
dual polarization scanning radar.
• Airborne radars are calibrated using both lab and external calibration
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Validation strategies and approaches
For representativeness / homogeneity /geometric distortion in space/time of clouds:• Airborne direct underpasses• ACTRIS: (a) Clustering of stations and comparison of cloud statistics. (b) By scanning operation(cloud radar and Doppler lidar) at some sites• Application of volume matching technique (developed for GPM tracking)• Use of historic data to assess representativeness during overpasses• Use of ceilometer (E-Profile) network to check representativeness• “Collocation
criteria for cirrus” and estimates of the impact of non-perfect collocation
Italy(Lampedusa)
Validation of precipitation products:• Use multi-λ radar observations (weather & cloud radars) + more detailed observations at stations,for direct validation (as done for GPM).
• Use synergistic A-Train products in Antarctica to evaluate the full chain of events leading toprecipitation.
• Combine radar and surface reports of precipitation• precipitation detection in MPL will be used for drizzle validation
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Validation strategies and approaches
Use of synergistic datasets:• Multi-λ radar will be used to provide frequency diversity• generation of synergistic products from several instruments to compare with EarthCARE synergisticproducts• Synergistically explore ground-based, airborne and satellite-based measurements for validation

Italy
Use (Lampedusa)of Simulators, models and retrievals:• Use of Monte Carlo simulations to address for multiple scattering effects in water clouds• In-house forward operator (ARMS) as EarthCARE to simulate cloud reflectance from model output.
• Comparing and interpreting the measurements by performing simulation of their "in situ" andEarthCARE lidar and radar observables.
• Running own retrievals combining more instruments than EarthCare or with different wavelengths.
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Validation strategies and approaches
Statistical analysis:• Statistical validation (i.e. deriving conclusions from many collocations) and in relation today/night differences and different aerosol types and cloud systems.
• MPLNET: Statistical analysis against monthly and seasonal means of cloud property
climatologies• Statistical intercomparison with other satellite sensors• Statistical validation, special attention to certain conditions, e.g. waves.
Use of Models:• Support by aerosol, cloud and radiation modelling aiming at the connection of observations
and the investigation of spatial and temporal variances of the measured parameters.
• EarthCARE cloud and aerosol products will be assessed against passive satellite imagery andglobal NWP predictions (systematic comparison).
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Validation strategies and approaches·Focus areas:•Snowfall, rain-to-snow transition, shallow melting layer, mixed-phase clouds.
•Estimation of the effective impact of urban environment•Hydrometeor classification, quantitative comparisons from top of the cloud and Doppler
velocity related cross validation.
•Cirrus clouds, low marine clouds, mixed-phase clouds.
Funding:• The majority of the proposals are looking for funding.
• Several proposals have partial funding (usually for operations of the instruments andnetwork-oriented data handling).

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So what are we missing or under-sample?
Uncertainty
CPR L2aLocations/scenes/regimes• Ice clouds at all latitudes• CFADs of reflectivity and Doppler velocity fromground-based radars

C-APC, C-CD

Doppler decomposition:
sedimentation + air motion• Unrimed/rimed snow
• Drizzle/rain• Convective/stratiform; other sources of vertical motion• Multiple-frequency Doppler radars• In-situ measurements

C-CD

Aerosol/cloud discrimination• Cloud embedded in aerosol layers• Ground-based lidars• Collocated in-situ aerosol samplingMacrophysics

RainProducts

Antenna pointing correction•
Cloud layer detection and structure •••Cloud spatial scales•••
Liquid clouds not fully resolved by •radar/lidar synergy•
CPR surface clutter removal•
Snow microphysics (e.g. PSDs,•
microwave scattering, density &•fallspeed)
Ice cloud Ice microphysics (e.g. PSDs, ice•
& snow optics, mass-size rel’n)LiquidcloudMeasurements needed

Multiple cloud layers
Cirrus over liquid cloud•Non-precipitating liquid clouds
Cumulus & stratocumulus clouds•
Land/sea, day/night, boundary layer conditions, etc.
Physical depth of liquid clouds (i.e. cloud base height)•Mixed-phase layers embedded in ice•
Liquid (& liquid-topped mixed-phase) clouds below optically thickice clouds•
Warm liquid clouds within cold rain•
Range of surface types••
Stratiform vs convective
Rimed snow•
Cloud-tops across range of temperatures, locations & cloud
•
types
•

Surface snow rate

• Range of meteorological conditions

How to account for radiativelyimportant liquid clouds notdetected by ATLID
Relation between rain rate anddrop size distribution•••••

Melting layer structure & radar
attenuation• Dependence on snow properties aloft• Continuity of mass flux & size distributions across melting layer

Deep ice clouds: embedded mixed-phase layers
Layered cloud scenes
Warm liquid clouds within cold rain
Warm rain (maritime)
Convective/stratiform rain

Ground-based (& scanning?) lidars & radiometers
High-resolution satellite imagery
Ground-based ceilometers/lidars
Multiple-frequency radars to constrain W-band
attenuationMicrowave radiometers for LWP
Aircraft profiles of LWC
Ground-based radars
Bulk precipitation and particle imaging
measurements at surface
Profiles of in-situ particle properties in ice clouds
In situ aircraft measurements
Visible & IR radiances• Ground-based radars and in-situ at surface

A-ALD,AM-ACD, A-TC
M-CLD,AM-CTH, A-TC,C-TC, AC-TC
M-CM
A-TC, C-TC,AC-TC
C-TC, C-FMR
C-CLD,ACM-CAP
A-ICE,ACM-CAP
C-CLD,ACM-CAP• Microwave radiometer for LWP• Profiles of liquid water content

ACM-CAP• Ground-based multiple-frequency radars• Dual-pol weather radars over ocean

C-CLD,
ACM-CAP• Ground-based & airborne multiple-frequency radar

C-CLD,
ACM-CAP13