CPR L2, cloud and precipitation validation

Discussion
ESA UNCLASSIFIED – For ESA Official Use Only1

SPECIFIC NEEDS FROM GROUND-BASEDSTATIONS• CFADs of Doppler radar measurements•

ice clouds as reference for Doppler velocity•

at low levels to evaluate surface clutter removal• for different particle conditions at the surface(i.e., rimed vs unrimed snow)• Correlation between radar reflectivity & mean Doppler velocity• important for antenna pointing corrections (C-APC)• Contextual information from complementary instruments:•LWP from microwave radiometers•

Precipitation measurements at the surface

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DATA STANDARDS FROMGROUND-BASED STATIONS & NETWORKS
Common approaches / strategies•

Collocation with EarthCARE•

quality control/calibration•

instrument limitations••

different radar frequencies

Use of complementary observations•

e.g. upcoming “spectral CloudNet” products

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GAPS IN SPECIFICTARGETS• Do we have ground-based
stations or field campaigns(existing or planned) in allimportant climatologicalregimes?
• How do we supplement
existing ground-based
stations to enhance theirvalue in Cal/Val activities?
•e.g. add lower frequency
profiling radars in certainsites
4WHAT IS THE ROLE OF AIRBORNE
MEASUREMENTS?
• How critical are direct aircraft underflights of EarthCARE?
•CPR L2•

Cloud•

Precipitation• Essential validation measurements?
•In-situ•

Remote-sensing• Relationships between retrieval model parameters (i.e., covariance between
number concentration and mean snow particles; scattering libraries)
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WHAT IS THE ROLE OF SATELLITEOBSERVATION (PoR) IN THE CAL/VAL ACTIVITIES?
• Statistical validation & continuity with future/previous satellites?
•CloudSat/CALIPSO•MODIS & other imager retrievals•

ACCP activities?

• Direct validation with complementary satellite observations(e.g. GPM, Aeolus, microwave radiometers, imagers)

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WHAT IS THE ROLE OF MODELS?
• ECMWF provision for EarthCARE• Cooperation with field campaigns & networks• Data Assimilation for active instrument monitoring (c.f. Aeolus); applications toEarthCARE’s CPR

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VALIDATING CLOUD RETRIEVALSFROM A NON-RADAR PERSPECTIVE• ATLID & MSI:
• Ice optics, IR and solar radiance models• Passive retrievals (M-COP)• Lidar retrieval (A-ICE)• ACM-RT & BBR:
• Sensitivity of ACM-RT and radiative closure toliquid clouds not detected by ATLID

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FUNDING NEEDS FOR EXISTING/PLANNEDDATASETS• Support is needed to develop the aforementioned data summaries andrelationships from existing ground-based stations and airborne field campaigns(e.g., how do we best make sure of excellent datasets collected by the ACCP
suborbital program?)• Are the data collected by field campaigns immediately useful to L2 Cal/Valactivities?
• Who is generating CFADs and statistical summaries?

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FORWARD SIMULATORS:BRIDGING BOTTOM-UP AND TOP-DOWN SAMPLING• Converting from ground-based to EarthCARE-like observations(e.g E3SIM, radar simulators, CR-SIM, FRM4Radar)• Can synergistic L2 retrievals (ACM-CAP & ACM-COM) be used
to model ground-based instruments?

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HOW CAN WE USE GROUND-BASEDNETWORKS?
• Precipitation validation using operational (polarimetric) weather radar networks:•US (NEXRAD), Europe (OPERA), Finland, UK, etc.

•Challenge: limited overlap between in moderate precipitation seen by both W-band andweather radars?

• Networks: how to make the most use of Actris, MPLnet, ARM networks?
• Target classification: cloud base, mixed-phase layers, etc.
• What about validating cloud & light precipitation retrievals?

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HOW DO WE MOVE FORWARD?

(DO WE HAVE TO CENTRALIZE THE PROCESS?)• Evaluation of algorithms before launch:• Aircraft campaigns with EarthCARE-like & EarthCARE+ payloads• Resources available for these activities?
• Preparations for statistical validation (before launch)• Preparations for direct validation (commissioning phase and beyond)12