Vision for ground aerosol networks: AERONET and MPLNET

•Operational Status•Science Results•Future Plans•Issues•??•

Brent Holben and Judd Welton

AERONET Status

• ~280 instruments• ~150-180 Operational

sites• Network Partners

– GSFC– Photons (France)– RIMA (Spain)– CSIRO (Australia)– AEROCAN (Canada)

• Expansion to Asia, Africa high latitudes and over water sites

Provide a long term data set to:•Characterize aerosol optical properties• Validate Satellite & model aerosol retrievals• Synergism with Satellite obs., climate change

AERONET Version 2 AOD

• Version 2 (AOD) implemented July 2005– Improved corrections: Satellite

• TOMS (Monthly gridded O3)

• SCIAMACY (Monthly gridded NO2)

– Improved corrections: NCEP/NCAR Reanalysis• Dynamic Air Pressure for Rayleigh, CO2 and CH4

correction

– Much improved and QA water vapor retrievals– Details: http://AERONET.gsfc.nasa.gov/version2-

table.pdf

AERONET Inversion 2

• Unified Inversion products from combined Sphere/Spheroid models

• Uncertainty Assessment w/ all products• Dynamic surface reflectances

– MODIS & IGBP Ecosystem reflectance (16 day product) + generic BRDF

– Cox-Munk for ocean sites (hybrid for coastal sites)– Snow and Ice from NISE product (daily)

• Inversion Products for PP retrievals• Forcing computations

AERONET Science

• Aerosol Characterization• Algorithm Development

– AOD– Retrievals

• Validation• Synergism• Blue Sky• Cockamamy

Significant Enabling:

•‘AERONET Paper’- 493 citations since 1998,134 citations in 2005

•Staff citations of keyAERONET papers since2000: 751

AERONET-OC(Ocean Color)

• SeaPRISM (cimel)• Normalized water

leaving radiances (Lwn)• 3 yr validation w/ in

water optics (Venice)• Standard AOT and

inversion products (nm): 412, 443, 490,

531, 551, 677, 870, 940, 1020

AERONET-MSP(multispectral polarization)

• Spectral linear Polarization hourly

• Standard Products• L(nm): 340, 380, 440,

500, 675, 870, 940, 1020, 1640

• AERONET testing (Feb. to May 2006)

• Operational products: June 2006 Dual filter wheel, top for polarizers

bottom for IAD filters

O b j e c t i v e l e n s e s + A p e r t u r e b a f f l e

2 f i l t e r s w h e e l s .

F i e l d b a f f l e s

C o n d e n s e u r l e n s

I n G a A s

S i

N o n p o l a r i z i n g m e a s u r e m e n t s

U V p o l a r i z e r : 2 8 5 t o 6 0 0 n m

V I S p o l a r i z e r : 5 0 0 t o 9 0 0 n m

N I R p o l a r i z e r : 9 0 0 t o 2 2 0 0 n m

U V

U V

9 4 0

1 6 4 0

4 4 0

5 0 06 7 0

8 7 0

1 0 2 0

AERONET support for Field Campaigns

• East AIRE-east China• Base Asia-Thailand• Milagro-Mexico• AMMA-W. Africa• ABC-damn near everywhere• ARM sites• RAJO-MEGHA: Indo-Gangenic Plain (2007)• Seven Seas-S. Asia and SE Asia (2007?)

AERONET Directions• Collaboration and co-location w/ BSRN and

MPLNET (extinction profile product)• Development of SolRad-Net (

http://solrad-net.gsfc.nasa.gov)• Cloud Optical depth retrievals• 2008-new Sun-Sky system to be phased in• 2008-CO2 network (±3ppm accuracy anticipated)• BAMGOMAS browser: Links to MODIS,

MPLNET, Gocart, backtrajectories for all AERONET sites

2/10/2006 Judd Welton et al., GSFC 613.1 MPLNET

The NASA Micro-Pulse Lidar Network: MPLNET

activeno longer activeplannedproposed

former experiment, permanent site plannedformer experiment, permanent site proposed

* line denotes research cruise

Objective: Acquire long-term observations of the vertical structure of aerosols and clouds using common instrumentation and data processing in a federated network. Focus on co-location with select AERONET sites.

Currently:11 active sites7 planned sites (in preparation)4 proposed sites (funding dependent)10 sites no longer active (mostly field campaigns*)1 Ocean cruise (two cruises pre-dating MPLNET are available)

* Most campaigns utilize SMART-COMMIT platform (Tsay et al. 613.2)

Goddard team + 11 Partners compose MPLNET:NASA LaRCNOAA ESRLNaval Research Lab - MontereyJapan’s National Institute of Polar ResearchSpain’s Instituto Nacional de Técnica Aeroespacial - INTA3 US Universities2 Korean Universities1 Taiwan University other partners pending

Overview and Current Status

2/10/2006 Judd Welton et al., GSFC 613.1 MPLNET

The NASA Micro-Pulse Lidar Network: MPLNETRecent Publication/Science Results

How well do state-of-the-art techniques measuring the vertical profile of tropospheric aerosol extinction compare?

B. Schmid, R. Ferrare, C. Flynn, R. Elleman, D. Covert, A. Strawa, E. Welton, D. Turner, H. Jonsson, J. Redemann, J. Eilers, K. Ricci, A. G. Hallar, M. Clayton, J. Michalsky, A. Smirnov, B. Holben, and J. Barnard, J. Geophys. Res., 111, D05S07, doi:10.1029/2005JD005837, 2006.

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Aerosol Extinction & Optical Depth profiles compared in most comprehensive study to date:• MPLNET (column AOT anchored to AERONET)• MPL from ARM• Airborne Ames Sunphotometer (AATS) • Airborne nephelometer & absorption photometer • Airborne cavity ring-down system (Cadenza)• Ground-based Raman lidar (CARL)

AATS used as truth• AATS is most direct measure of AOT profile• AATS Column AOT within 2% of AERONET

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AOT

Alti

tud

e (

km)

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Extinction 1/km

Alti

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km)

MPLNETMPL ARMNeph/PSAPAATS

Example Comparisons from study (25 Days total).Also surveyed past 7 field campaigns of such work.

Instrument (visible wavelengths, ~520 nm) Bias Error relati ve to AATS Cadenza - 13% Neph / PSAP - 15% MPLNET + 13% MPL ARM + 24% CARL (Ra man) + 54% Neph / PSAP Mean from 7 Ca mpa igns - 17% Size Dist. Der ived Mean from 3 Campa igns - 18% MPLNET Mean from 5 Ca mpaigns < + 20% ( work in prog ress)

Summary of Study Results: MPLNET among best performers

Conclusion: state-of-the-art techniques remain 15 - 20% uncertain

MPLNET meets or exceeds that target range

AATS-14 shown above

2/10/2006 Judd Welton et al., GSFC 613.1 MPLNET

The NASA Micro-Pulse Lidar Network: MPLNETFuture Plans, Network Growth, & News

South Pole MPLNET Site: 1999-2006

Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations

New Generation MPL: Type 4BAvailable from Sigma Space Corp.

• MPL and MPLNET recently won Tech Transfer award from Federal Laboratory Consortium

• MPLNET team currently working with Sigma to incorporate athermal telescope for improved instrument stability in field

MPLNET will contribute to International Polar Year activities

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African Monsoon Multidisciplinary Analysis

Our future long term site in Senegal will also support the AMMA campaign, but is not dependent upon NAMMA funding (US). Our NASA MOU with Ecole Supérieure Polytechnique in Dakar is near completion.

In addition, our current long term site in the Canary Islands will support AMMA, and a proposed SMART-COMMIT site on Cape Verde may also participate.

MPLNET is a part of the established CALISPO cal/val plan, and we are gearing up for validation activities after launch.

• Direct validation of layer heights, extinction, AOT• Statistical seasonal studies• Look Up Table development: aerosol extinction-to-backscatter ratio

2/10/2006 Judd Welton et al., GSFC 613.1 MPLNET

The NASA Micro-Pulse Lidar Network: MPLNET

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2/10/2006 Judd Welton et al., GSFC 613.1 MPLNET

The NASA Micro-Pulse Lidar Network: MPLNET

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Aerosol Extinction 1/km

Altitude (km)

AOD: 0.714 + 0.01

C: 180 + 9

Sa: 64 + 4 sr €

km3 • sr

μJ • μs

122 123 124

20

18

16

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Day of Year (UTC)

Altitude (km)

-0.2-0.1-0.00.10.20.30.40.50.60.70.70.80.91.01.11.21.31.4mplnet_335_19_3634_Gsfc_nrb_txt

MPLNET:Combined Active Lidarand Passive Photometer

Continuous MPLNET lidar observations

PBL structure & evolution readily apparent

Retrieved Aerosol Extinction Profile

AERONET column Aerosol Optical Depth (AOD) observation used as constraint to retrieve vertical profile of aerosol extinction from the MPL

Aerosol extinction-to-backscatter ratio is calculated, thisparameter is required for satellite retrieval of extinction

Data Retrieval: Aerosol Extinction Profile