Aeolus Aerosol and Cloud Product Validation Approaches ... · countries. Five partners are new to the consortium: ECM WF, UNIVL EEDS, RIUUK, FM I, and CyI. The first three reflects

Aeolus Aerosol and Cloud Product

Validation Approaches using the Cabauw

Experimental Site for Atmospheric Research

and EARLINET

Arnoud Apituley, KNMI, NL and co-proposers

Outline

• General approach by two AO teams

• Cabauw

• EARLINET/ACTRIS

• Summary

Aeolus CAL/VAL workshop, Feb. 2015, Frascati

General approach • Various issues exist with Aeolus

instrumental features and processing algorithms, e.g.

- Effects of sampling strategies - Complex scenes/heterogeneity - Effects of shear - Effects of aeolus bin size – centre of

gravity analysis - Wind/cloud performance - Effective resolution - Mie sampling will be changed according

to conditions - Context sensitive along track

aggregation - Zero wind calibration issues

• Ground-based stations have the ability to provide spatio-temporal development of the state of the atmosphere for many parameters simultaneously, and in much greater detail than from space. This offers a unique opportunity for validation of observations from space


L2A and L2B – Comparison with wind and optical products measured by ground based (or airborne systems).

General approach


• Validation of Aeolus wind, aerosol and cloud profiles of backscatter, extinction and lidar-ratio using ground based observations during close proximity overpasses.

• Assessment of representativeness of Aeolus wind, aerosol and cloud products using time series of ground based observations.

• Assessment of local cloud and aerosol conditions on Aeolus retrieved wind profiles based on ground based records of the atmospheric state.

• Validation of Aeolus L2A products of aerosol and cloud profiles of backscatter, extinction and lidar-ratio,

• Assessment of spatio-temporal representativeness of Aeolus aerosol and cloud products.


EARLINET CAL/VAL goals

EARLINET Approach

• The objectives will be accomplished through correlation between ground based lidar data from EARLINET stations. For this, data will be used from:

• The (historical) EARLINET database,

• Correlative measurements performed by selected EARLINET stations during close proximity Aeolus overpasses.


Multiwavelength Raman lidars (red), Raman lidars (green), backscatter (purple) aeronet (yellow), depol. (Pappalardo et al., AMT, 2014)

EARLINET Approach Proposed observation schedule is proposed according to overpasses related to clusters of lidar stations

• Case 1 measurements: Each

station performs measurements as close as possible in time and space to the Aeolus overpasses. For validation studies, measurements made within 2 h and 40 km of the satellite overpass are preferred, but within 4 h and 100 km are acceptable.

• Case 2 measurements: Additional correlative observations are suggested to be made at the lidar station which is closest to the station of the actual Aeolus overflight.

• Case 3 measurements: If Aeolus passes over a multi-wavelength Raman lidar station (high-performance station) then also the neighbouring high-performance station performs a measurement.


Pappalardo et al., JGR, 2010

[ACTRIS-2]

3.3 Consortium as a whole

The ACTRIS-2 consortium is organized on the basis of ACTRIS with 22 identical beneficiaries and 4 newly

formed Joint Research Units (JRU) reflecting growing importance of ACTRIS in the last 4 years in some EU

countries. Five partners are new to the consortium: ECMWF, UNIVLEEDS, RIUUK, FMI, and CyI. The

first three reflects the ACTRIS-2 strategy to include stronger expertise in atmospheric modelling, data

assimilation and use of satellite products in the consortium and work together to elaborate data-product most

suited to modelling needs. Participation of FMI adds expertise for database management and development

within the ACTRIS Data Centre and a long-term measurement station in the Arctic. Participation of CyI

reflects the strong investments made by Cyprus to equip and operate an observing station and the strong

expertise in aerosol science the team has built in recent years. Overall, the consortium brings complementary

expertise in all fields relevant to observation, from data provision to data usage and can now address

challenges with the holistic approach needed to propose services suited to the user community. The

ACTRIS-2 consortium is already comprehensive with more than 60 associated partners. Figure 3.3 reports

the distribution of all the measurement sites contributing to ACTRIS-2.

Clearly, ACTRIS-2 brings together communities on the pan-European scale to create the critical mass

required to impact on the European observation strategy. The project consortium is strengthened by the

inclusion of institutes from most European countries, linking to their national strategies. Many participants in

ACTRIS are also involved in other existing research initiatives at EU and member-state levels. Capitalizing

on ACTRIS, the consortium brings complementary expertise in many different domains and has, for some of

its partners, a long history of collaboration in INFRA and RTD projects. This ensures very minimal risk of

problems in the partnership.

While no commercial company is partner to the project, innovation and links with SMEs are central in

ACTRIS-2. Industrial involvement in the project comes from participation of SMEs in NA and JRA

activities and use of services, in particular calibration services. It is clearly expected that developments that reached sufficient technology readiness level (TRL) may rapidly be included in prototypes as part of joint

agreements between a specific ACTRIS-2 partner and a specific private partner. Organization of NA4 to

coordinate links with industries favors establishment of these joint ventures.

Figure 3.3: Map of measurement sites contributing to ACTRIS.

This proposal version was submitted by Gelsomina Pappalardo on 02/09/2014 16:47:39 CET . Issued by the Participant Portal Submission Service.

EARLNET Workplan WP01 – Measurement plan preparation (L-3 – L+18)

WP02 – Database set-up and exchange (L-3 – L+18)

• The data exchange between EARLINET and ESA (EVDC) will take into account QA4EO guidelines.

WP03 – Main correlative observational period (L+0 – L+18)

• We estimate that 40 to 50 evaluated observational cases can be available at L+3 and can serve for a very first quality check by the end of phase E1.

• The main focus of EARLINET is on the long-term validation (Phase E2).

WP04 – Data evaluation phase (L+3 – L+21)

• Various Aeolus aspects will be taken into account. Experience gained in Calipso validation will be used.

WP05 – Reporting (L+3, L+21, L+24)

• CalVal validation workshop attendance

• Symposium attendance

• Proceedings and peer reviewed publications Aeolus CAL/VAL workshop, Feb. 2015, Frascati

EARLINET contribution

• Quantification of accuracy of aerosol and cloud geometrical and optical parameters using a ground-based network of quantitative aerosol and cloud lidars.

• Characterise deviations of the Aeolus-L2A products from ground truth established by the lidar network.

• Recommendations for improvement to processing algorithms based on intercomparison between observations from space and ground. Initial results, based on a limited dataset from ground-based measurements, can be provided after completion of Phase E1.

• Monitoring of product stability over the observational period foreseen in the proposal.

• Main focus on long term.


CESAR Observatory

Cabauw Experimental site for Atmospheric Research A “Field Laboratory”

51.971° N, 4.927° E, -0.7 m ASL


CESAR Observatory Cabauw Experimental site for Atmospheric Research A “Field Laboratory”

CESAR Observatory Cabauw Experimental site for Atmospheric Research A “Field Laboratory”

UV-lidar Ceilometer

Raman Lidar Wind profiler


Remote Sensing Site Drizzle

suveillance radar

In-situ meteo

In-situ Aerosol

Radiation site (BSRN, Aeronet)

Cabauw CAL/VAL goals

• Validation of Aeolus wind, aerosol and cloud profiles of backscatter, extinction and lidar-ratio using CESAR observations during close proximity overpasses.

• Assessment of representativeness of Aeolus wind, aerosol and cloud products using time series of CESAR observations.

• Assessment of local cloud and aerosol conditions on Aeolus retrieved wind profiles based on CESAR records of the atmospheric state.


Cabauw Approach

• The objectives will be accomplished through correlation between ground based remote sensing data from the Cabauw station.

• Data will be used from the operational CESAR suite of instrumentation, in particular the wind profiler, radars and lidars.

• Additional correlative measurements can performed by manually or semi-automated instruments during close proximity Aeolus overpasses.

• Linking may be possible with other campaign activities, e.g.

• Airborne Aeolus CAL/VAL activities

• Sentinel-5p/TROPOMI


Cabauw main instrumentation


Instrument Wind

Temperature

AerosolBackscatter

AerosolExtinction

AerosolOpticalDepth

Clouds

Polarisation

Humidity

Profile

24/7operation

Windprofiler LAP30001290MHzWINDPROFILER/RASS x x x xCaeli MultiwavelengthRamanlidar (x) x x x x x x x (x)

UV-lidar LeosphereALS-450 x x x x xCeilometer LD40 x x x x

3GHzcloudradar TARA x x x x x35GHzCloudradar PDN100 x x x x

Microwaveradiometer RPG-HATPRO x x x xAERONET Cimel x xNubiscope x x

TotalSkyImager xRadiosonde VaisalaRS92 x x x x

Illingworth, BAMS, 2007 Figs. 2, 3

Cabauw Workplan WP01 – Measurement plan preparation – L-3 – L+18 WP02 – Database set-up and exchange – L-3 – L+18 • The data exchange between CESAR and ESA (EVDC) will take into account

QA4EO guidelines. WP03 – Main observational period – L+0 – L+18 • We estimate that several evaluated observational cases can be available at

L+3 and can serve for a very first quality check by the end of phase E1. • The main focus of EARLINET is on the long-term validation (Phase E2). WP04 – Data evaluation phase – L+3 – L+21 • Various Aeolus aspects will be taken into account. WP05 – Reporting – L+21 – L+24 • CalVal validation workshop attendance • Symposium attendance • Proceedings and peer revirewed publications


Cabauw contribution

• Quantification of accuracy of aerosol and cloud geometrical and optical parameters using a ground-based network of quantitative aerosol and cloud lidars.

• Characterise deviations of the Aeolus-L2A products from ground truth established by the lidar network.

• Recommendations for improvement to processing algorithms based on intercomparison between observations from space and ground. Initial results, based on a limited dataset from ground-based measurements, can be provided after completion of Phase E1.

• Monitoring of product stability over the observational period foreseen in the proposal.

• Main focus on long term.


Summary

• Proposals offered for collection and analysis of Aeolus L2A and L2B data, based on ground based remote sensing

• Observation strategies have been outlined for collecting correlative data and analysis for various Aeolus issues

• The Cabauw site offers an extensive set of observations to record the atmospheric state, enabling detailed analyses of Aeolus instrument and retrieval issues

• The EARLINET network has shown utility for the investigation of spatial and temporal representativeness of measurements with polar‐orbiting satellites, and can be applied for Aeolus

• These infrastructures and activities can be aligned with other CAL/VAL proposals, e.g. airborne activities.


Documents

Aeolus Aerosol and Cloud Product Validation Approaches ... · countries. Five partners are new to the consortium: ECM WF, UNIVL EEDS, RIUUK, FM I, and CyI. The first three reflects