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May 2004, El Arenosillo, Spain

Solar Irradiance Measurements and AERONET- An Overview Joel Schafer, Brent Holben, Tom Eck: NASA/GSFC Paulo Artaxo, Gilberto Nishioka: USP, Brazil. May 2004, El Arenosillo, Spain. Amazonian Solar Flux Network. AERONET / LBA Flux & AOT Sites.

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May 2004, El Arenosillo, Spain

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  1. Solar Irradiance Measurements and AERONET- An OverviewJoel Schafer, Brent Holben, Tom Eck: NASA/GSFCPaulo Artaxo, Gilberto Nishioka: USP, Brazil May 2004, El Arenosillo, Spain

  2. Amazonian Solar Flux Network

  3. AERONET / LBA Flux & AOT Sites

  4. Network DetailsSix Amazonian sites (four since 1999)CIMEL sunphotometer data [AOT, WV,g, SSA, ni, nr, dV/d(ln r)]2-min instantaneous flux measurements PAR(400-700nm) Filtered pyranometer (695-2800nm) Pyranometer (285-2800nm)

  5. Daily Pyranometer Insolation Alta Floresta Belterra

  6. LBA-related Publications JS Schafer, BN Holben, TF Eck, MA Yamasoe, and P Artaxo, “Atmospheric Effects On Insolation In The Brazilian Amazon: Observed Modification Of Solar Radiation By Clouds And Smoke And Derived Single Scattering Albedo Of Fire Aerosols”, J. Geophys. Res., 10.1029/2001JD000428, 11 September 2002 JS Schafer, TF Eck, BN Holben, P Artaxo, MA Yamasoe, and AS Procopio “Observed Reductions of Total Solar Irradiance by Biomass-Burning Aerosols in the Brazilian Amazon and Zambian Savanna”, Geophys. Res. Lett., 10.1029/2001GL014309, 05 September 2002

  7. A. S. Procopio, P. Artaxo, Y. J. Kaufman, L. A. Remer, J. S. Schafer, B. N. Holben, “Multiyear Analysis of Amazonian Biomass Burning Smoke Radiative Forcing of Climate”, Geophys. Res. Lett., Vol. 31, L03108, doi:10.1029/2003GL018646, 2004 TF Eck, T.F., B.N. Holben, J.S. Reid, N.T. O'Neill, J.S. Schafer, O. Dubovik, A. Smirnov, M.A. Yamasoe, and P. Artaxo, ‘High aerosol optical depth biomass burning events: A comparison of optical properties for different source regions’, Geophys. Res. Lett., 30(20), 2035, doi:10.1029/2003GL017861, 2003.

  8. Rio Branco, Acre

  9. Fractional and absolute reductions in flux due to smoke were calculated for total broadband irradiance.The fractional reduction was computed as the ratio of received irradiance to the modeled clear-sky irradiance for background (low) aerosol conditions.

  10. Observed Reduction of Solar Irradiance by Smoke AerosolCloud-screened flux measurements were plotted as a function of smoke AOT for two southern Amazonian sitesThree Zambian sites influenced by biomass burning were also evaluated in this fashion to compare the absorption properties of smoke aerosols typical of each region

  11. Broadband Irradiance Reduction by Smoke [from Schafer et al., GRL 2002]

  12. Comparison of Brazilian and African Smoke Properties

  13. Future Plans Flux tool (calibration and data access) Expansion of network to Eurasia (NEESPI*) New investigation of diffuse flux fraction Augment one instrument suite with sun tracker for shaded pyranometers, shadowband *Northern Eurasia Earth Science Partnership Initiative

  14. Effect of Clouds and Aerosols on Photosynthesis?Atmospheric aerosols modify the incident PAR radiation field in a manner that can have a dramatic effect on net primary productivity (NPP), most commonly as a result of increasing the diffuse component of received sunlight.Grasses and trees may make use of diffuse light twice as effectively as direct (Gu et al. 2002)

  15. Diffuse Flux and Photosynthesis NPP (grams C m-2 s-1)= Net Primary Production = Photosynthesis - Respiration [Gu et al., 1999]

  16. AOT and Biological Productivity Initial Conditions Increasing AOT a) b) Case a) increases diffuse flux and Light Use Efficiency (LUE) Case b) decreases diffuse flux as most PAR is already diffuse [Cohen et al., 2002]

  17. Additional Factors Lower  Leads to Less Diffuse Flux and Greater Total PAR Reduction Type of Biomass Burning Determines the Degree of Modification of PAR Energy Distribution Net Effects of Partial Cloud Cover Are Challenging to Model, and Thus Field Measurements for Such Conditions Are Particular Valuable

  18. Flux Data Base Tool In Development: Interactive in-situ calibration (PAR) Descriptive flagging of quality issues Analysis/diagnostic tools (derived products) Web-based simple interface for public users to view and download Level 2.0 flux data

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