MPLNET Observations in Support ofEarthCARE Cal/Val
2nd ESA EarthCARE Validation Workshop
25-28 May 2021 (online)
Ellsworth J. Welton (NASA), Jasper R. Lewis (UMBC/NASA),James R. Campbell (NRL), Simone Lolli (CNR)
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MPLNET: Overview and News Since Last Workshop
MPLNET Sites: 2000 - current

MPLNET - Global Backscatter Lidar Network: 2000 - current•
75 sites total (25 active, 50 inactive). 27 countries, 45 partners.
•7 more planned sites•
Continuous (day/night) operations•
97% of network co-located with AERONET•
Created using AERONET model: federated network with centralized andstandardized calibration, processing, distribution. Same open data policy(with co-authorship offer).
Instrumentation:•
Micro Pulse Lidar (NASA developed, commercial since 1995)•
Eye safe, green backscatter lidar. Polarized in early 2000s•
Entire network has polarized MPL since ~2016
ESA EarthCARE MPLNET Validation Team: Ellsworth J. Welton (PI), J.R. Lewis (Co-I), J.R. Campbell (Co-I), S. Lolli (Co-I)•Baseline MPLNET funding will provide support of site operations (joint with our international partners), and calibration, QC/QA, data processing(raw to L1,L1.5,L2,L3), and data archival and distribution•PI Welton is the POC for deployment of new MPLNET sites specific to EarthCARE validation

NASA Participating Investigator Program Validation Team: 5 YR (2021-2026) Proposal to support our EarthCARE validation was funded• Jasper R. Lewis (PI). Co-Is: E.J. Welton (Co-I), J.R. Campbell (Co-I), S. Lolli (Co-I). Collaborators: Rob Koopman (ESA), Michaël Sicard (UPC)• This effort will fund MPLNET-EarthCARE data analysis and development of EarthCARE specific L3 products to be uploaded to EVDC
• Jasper will be the primary POC for MPLNET – EarthCARE validation products and studies
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2nd ESA EarthCARE Validation Workshop | 25-28/05/2021 | Slide 2

MPLNET: Version 3 Product Suite
Online Product Information: https://mplnet.gsfc.nasa.gov/product-info/

Version 3 Products••EarthCARE cal/val will focus only on variables notdependent upon wavelength (MPL at 532 nm)
All products contain variable uncertainties andQA flags

PRC:Light Precipitation product in beta test

Version 3 Product Levels•••

All L1 and L1.5 products available in NRT (< 1 hour)
via automated data transfer and processing
NRT QA screen applied at L1.5, final QA at L2
L3 products in development (created from L2 data)

Version 3 Variable Confidence Flags••

New for Version 3, in all products
Based on maturity of variable algorithm and QC/QA
flags

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2nd ESA EarthCARE Validation Workshop | 25-28/05/2021 | Slide 3

MPLNET: Version 3 Product Suite Examples
MPLNET GSFC: 2017-03-16 to 2017-03-20

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MPLNET: NRB Product Signal Calibrations and QA Flags
Original MPL Calibrations and Signal Processing:• Detector Deadtime• Campbell, J.R., et al, 2002. Full-time, Eye-Safe Cloud and Aerosol Lidar Observation at Atmospheric Radiation• Dark Count
Measurement Program Sites: Instrument and Data Processing, J. Atmos. Oceanic Technol., 19, 431-442.
• Afterpulse•
Welton, E.J., and J.R. Campbell, 2002. Micro-pulse Lidar Signals: Uncertainty Analysis, J. Atmos. Oceanic• Range offset corrections
Technol., 19, 2089-2094.
• Overlap (old method: Version 1)• Raw to Relative Attenuated Backscatter (C•ATB)•Updated Overlap calibrations using additional •wide field receiver (Version 2 – 3)
• Done at GSFC, transferred to MPLs
• Coming soon, WFR deployed to all MPLs
in network

T. A. Berkoff, et al, 2003. Investigation of overlap correction techniques for the Micro-Pulse Lidar NETwork(MPLNET). IGARSS 2003. doi: 10.1109/IGARSS.2003.1295527.

Polarized MPL Calibrations and Signal Processing:• Original polarized MPL (not used in MPLNET)• Basic operation unchanged in new polarized MPL••••••New Polarized MPL (Ferroelectric Liquid Crystal, FLC)
Deadtime to Overlap calibration methodology unchanged
Polarized Model of new polarized MPL developed
FLC Polarimeter study. Mueller matrix retrieved from 20–30 C
Calibration approach developed using FLC parameters,
polarizing split cube, etc.. and polarized MPL model
Corrects for both diattenuation and retardance variations
leading to cross talk. Gain ratio negligible as MPL is atransceiver. Cross talk bias reduced to < 1%

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Flynn C.J., et al, 2007. Novel polarization-sensitive micropulse lidar measurementtechnique. Optics Express, 15, 2785-2790, https://doi.org/10.1364/OE.15.002785.

•Welton, E.J., et al, 2018. Status of the NASA Micro Pulse Lidar Network (MPLNET):
Overview of the network and future plans, new Version 3 data products, and thepolarized MPL. ILRC 2018. EPJ Web of Conferences, 176,
https://doi.org/10.1051/epjconf/201817609003.

•NOTE: Full paper on the calibration, processing, and long-term characterization ofthe polarized MPL is in preparation (delayed from last year due to COVID).

2nd ESA EarthCARE Validation Workshop | 25-28/05/2021 | Slide 5

MPLNET: NRB Product Signal Calibrations and QA Flags

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All of the detailed flag data aresummarized in final QA flag below•

This flag is carried forward to all
retrieved products to describe signalquality.

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MPLNET Retrieved Products: References
Cloud:•Lewis, J.R., J.R. Campbell, E.J. Welton, S.A. Stewart, and P.C. Haftings, 2016. Overview of MPLNET Version 3 Cloud Detection.
J. Atmos. Oceanic Tech., 33, 2113 – 2134, doi: 10.1175/JTECH-D-15-0190.1.

•

Lewis, J.R., J.R. Campbell, S. Lolli, S.A. Stewart, I. Tan, and E.J. Welton, 2020. Determining Cloud Thermodynamic Phase fromthe Polarized Micro Pulse Lidar. Atmos. Meas. Tech., 13, 6901–6913, https://doi.org/10.5194/amt-13-6901-2020

Aerosol:•Welton, E.J. K.J. Voss, H.R. Gordon, H. Maring, A. Smirnov, B. Holben, B. Schmid, J.M. Livingston, P.B. Russell, P.A. Durkee, P.
Formenti, M.O. Andreae, 2000. Ground-based Lidar Measurements of Aerosols During ACE-2: Instrument Description, Results,and Comparisons with other Ground-based and Airborne Measurements, Tellus B, 52, 635-650.

•Welton, E.J., K.J. Voss, P.K. Quinn, P.J. Flatau, K. Markowicz, J.R. Campbell, J.D. Spinhirne, H.R. Gordon, and J.E. Johnson,
2002. Measurements of aerosol vertical profiles and optical properties during INDOEX 1999 using micro-pulse lidars, J.
Geophys. Res., 107, 8019, doi:10.1029/2000JD000038.

PBL:•Lewis, J.R., E.J. Welton, A.M. Molod, and E. Joseph, 2013. Improved boundary layer depth retrievals from MPLNET, J. Geophys.
Res., 118, 9870-9879, doi:10.1002/jgrd.50570.

Precipitation:•Lolli, S., G. Vivone, J.R. Lewis, M. Sicard, E. J. Welton, J.R. Campbell, A. Comeron, L. P. D’Adderio, A. Tokay, A. Guinta, and G.
Pappalardo, 2020. Overview of the new Version 3 MicroPuLse NETwork (MPLNET) automatic precipitation detection algorithm.
Remote Sens. 12(1), 71; https://doi.org/10.3390/rs12010071

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MPLNET: Validation of our products
Series of papers validating MPLNET extinction & AOD profile retrievals against NASA Ames Airborne Tracking Sunphotometer•Validation of our aerosol retrieval technique using AERONET AOD as constraint (Welton et al 2000)•Indirectly validates our lidar calibrations and QA process as the aerosol retrievals are very sensitive to all cals (especially theoverlap)
Schmid, B., et al, 2000. Clear sky closure studies of lower tropospheric aerosol and water vapor during ACE-2 using airborne sunphotometer,
airborne in-situ, space-borne, and ground-based measurements, Tellus B, 52, 567-592
Schmid, B., et al, 2003. Coordinated airborne, spaceborne, and ground-based measurements of massive, thick, aerosol layers during the dry
season in Southern Africa, J. Geophys. Res., 108, 8496, doi:10.1029/2002JD002297
Livingston, et al, 2003. Airborne Sun photometer measurements of aerosol optical depth and columnar water vapor during the Puerto Rico
Dust Experiment and comparison with land, aircraft, and satellite measurements, J. Geophys. Res., 108, 8588, doi:10.1029/2002JD002520
Schmid, B., et al, 2006. How well do state-of-the-art techniques measuring the vertical profile of tropospheric aerosol extinction compare?, J.
Geophys. Res., 111, D05S07, doi:10.1029/2005JD005837•Schmid et al 2006: State of the art aerosol extinction measurement intercomparisons•MPLNET met the average bias, and exceeded some other techniques•

We now have some joint sites with both EARLINET and LALINET, which offer opportunities for inter-network comparisons• No joint sites with ADNET yet, but this could be done (many MPLNET sites in Asia)•Our partners at UMBC operate numerous ceilometers and lidars, and could provide a US based inter-calibration site that
already has MPLNET and is near our HQ at NASA.

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2nd ESA EarthCARE Validation Workshop | 25-28/05/2021 | Slide 8

MPLNET: Level 3 Products in DevelopmentExploit Diurnal Capability of Long-term MPLNET Data•

12 sites with 10+ years of data•

10 sites with 5 – 9 years of data•

2 sites with 20+ years of data (GSFC and South Pole)•We are developing L3 products for the first time•

Objective: go from instantaneous L2 profiles tomonthly, seasonal, annual, and decadal climatologies•

Standard L3 product files will be monthly diurnal
averages for full product suite (NRB, CLD, AER, PBL)

•Custom L3 products will be developed for EarthCARE•

This provides a statistical approach for EarthCARE
validation that avoids problems matching groundbased observations with direct satellite overflights(especially important for narrow swath instruments)

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MPLNET L3 Decadal Examples:

2010-2020 GSFC

2nd ESA EarthCARE Validation Workshop | 25-28/05/2021 | Slide 9

MPLNET: EarthCARE Cal/Val•

Task 1: Validate aerosol, cloud, and planetary boundary layer heights• L3-EC products will be provided to the EVDC (new templates needed?)• Same statistical analysis used for standard MPLNET L3 products, butconstrained to within 200-km /2-hr of EarthCARE overpass• Considerations• Known differences in wavelength (532-nm vs. 355-nm) andmeteorological parameters (GEOS-5 vs. ECMWF)• Narrow MPL FOV (~100 µrad) minimizes multiple scatteringeffects•

Task 2: Compare drizzle occurrence and properties• Automated precipitation detection has been incorporated into MPLNET processing (beta testing)• Will be used to identify potential case studies for drizzle from CPR products (C-TC, C-CLD)

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MPLNET: EarthCARE Cal/Val•

Task 3: Evaluate EarthCARE-based cirrus datasets for TOA CRE (top-of-atmosphere cloud radiative effect)•Fu-Liou-Gu model used to solve cirrus cloud radiative
properties of single-layered cirrus clouds•

Results from EarthCARE will be compared to similar
TOA CRE from MPLNET and historical CALIPSO dataset•

See series of papers (2016 – current) on cirrus
TOA forcing on MPLNET website•

A comparison of MPLNET and CALIOP-derived cirrus
TOA net CRE•

CALIOP seemingly fails to resolve some of the opticallythinnest cirrus•

The cirrus TOA net CRE is stronger (more negative) thanthat solved from MPLNET data•

How well will EarthCARE resolve thin cirrus?

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2nd ESA EarthCARE Validation Workshop | 25-28/05/2021 | Slide 11

MPLNET: Conclusion

Thanks!

Windpoort, Namibia
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mplnet.gsfc.nasa.gov
2nd ESA EarthCARE Validation Workshop | 25-28/05/2021 | Slide 12