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Narrowing the Uncertainty in Aerosol Radiative Forcing by Combining Suborbital and Satellite Measurements in Interagency/International Field Programs. Phil Russell, NASA Ames Research Center. Department of Energy Atmospheric Science Program Annual Science Team Meeting Annapolis MD
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Narrowing the Uncertainty in Aerosol Radiative Forcing by Combining Suborbital and Satellite Measurements in Interagency/International Field Programs Phil Russell, NASA Ames Research Center Department of Energy Atmospheric Science Program Annual Science Team Meeting Annapolis MD 25-27 February 2008
Structure of Talk Past • Future dRF dRF dRF AR4 P. Russell, DOE-ASP Meeting, Annapolis, MD, 27 Feb 2008
Structure of Talk DC-8 C-130 B200 J31 TARFOX, 1996 STARS,1975 ACE-2, 1996 INTEX-B 2006 ARCTAS-ISDAC 2008 SAFARI 2000 ACE-Asia, 2001 TAR INTEX-A, 2004 AR4 P. Russell, DOE-ASP Meeting, Annapolis, MD, 27 Feb 2008
A Chain of Field Experiments Measuring Aerosols & Their Effects on Atmospheric Radiation ICARTT MILAGRO TARFOX PRiDE ACE-Asia INTEX POLARCAT ACE-2 SAFARI CLAMS AIOP -A -B ARCTAS EVE ADAM ISDAC TAR AR4 Models frozen Simulations complete Models frozen Simulations complete Published Published P. Russell, DOE-ASP Meeting, Annapolis, MD, 27 Feb 2008
IPCC Definitions 1996: What is Radiative Forcing? A change in average net radiation at the top of the troposphere…. [It] perturbs the balance between incoming and outgoing radiation. • 2007 (AR4): • [unmodified] • Radiative Forcing (RF) • D1750 to 2005 [for aerAnthro] • Global average • Tropopause or TOA • Direct Radiative Effect (DRE) • Current, any aerosol • TOA, surface, within atmos, … P. Russell, DOE-ASP Meeting, Annapolis, MD, 27 Feb 2008
(TAR) IPCC (2001)
IPCC 2007: We’ve turned it on it’s side. Why? [Haywood & Schulz, Kaufman Symposium]
IPCC TAR: Mean = 0.36 Wm-2 Median = 0.64 Wm-2 P(RF<0) = 28.4% • The main reason for better quantification: • aerosol direct effect, • aerosol indirect effect IPCC AR4: Mean = 1.47 Wm-2 Median = 1.50 Wm-2 P(RF<0) = 0.4% Haywood and Schulz , GRL 2007
Does this smaller dRF reflect this tapestry of field programs? DC-8 C-130 B200 J31 TARFOX, 1996 STARS,1975 ACE-2, 1996 INTEX-B 2006 ARCTAS-ISDAC 2008 SAFARI 2000 ACE-Asia, 2001 TAR INTEX-A, 2004 AR4 P. Russell, DOE-ASP Meeting, Annapolis, MD, 27 Feb 2008
D1750 to 2005 [for aerAnthro] • Global average • Tropopause or TOA IPCC WG1, 2007 [AR4] Figure 2.13
MODIS-Terra AOD (0.55 mm) Figure 2.11 AERONET sites Lidar network sites: EARLINET ADNET MPLNET
D1750 to 2005 [for aerAnthro] • Global average • Tropopause or TOA Figure 2.13 IPCC WG1, 2007 [AR4] P. Russell, DOE-ASP Meeting, Annapolis, MD, 27 Feb 2008
What, then, is the role of field programs (like TARFOX, …, ARCTAS-ISDAC) in reducing the uncertainty in Aerosol Radiative Forcing? • Improving satellite retrieval algorithms & models by: • Testing satellite data products (validation) • Determining actual aerosol properties • Determining the processes leading to #2 • Measuring aerosol radiative effects & testing closure between measured radiation & aerosol optical & physiochemical properties • Testing models P. Russell, DOE-ASP Meeting, Annapolis, MD, 27 Feb 2008
Ghan & Schwartz, BAMS 2007 P. Russell, DOE-ASP Meeting, Annapolis, MD, 27 Feb 2008
Ghan & Schwartz, BAMS 2007: These 0-D models (modules) are also used, refined, & often developed in the analysis of field program data. They get incorporated, not just into climate models, But also into satellite retrieval algorithms. P. Russell, DOE-ASP Meeting, Annapolis, MD, 27 Feb 2008
What is the role of field programs in reducing the uncertainty in Aerosol Radiative Forcing? • Improving satellite retrieval algorithms & models by: • Testing satellite data products (validation) • Determining actual aerosol properties • Determining the processes leading to #2 • Measuring aerosol radiative effects & testingclosure between measured radiation & aerosol optical & physiochemical properties • Testing models P. Russell, DOE-ASP Meeting, Annapolis, MD, 27 Feb 2008
TARFOX, 1996 Aerosol Optical Depth Derived from Upward Scattered Solar RadianceAVHRR/NOAA 11, June-Aug., Husar et al., J. Geophys. Res., 102, 16,889, 1997.
TARFOX as a Stepping Stone to the State of the Art DC-8 C-130 B200 Kaufman Symposium 30 May-1 June 2007 Greenbelt, MD J31 STARS 1975 TARFOX 1996 INTEX-B 2006
TARFOX-measured and calculated aerosol-induced changes in radiant flux (DaFlux↓) vs AOD We found the predicted flux changes! 24-hr avg. DaF¯ (W m-2) Aerosol Optical Depth (300-700 nm) above Measurement Hignett et al., JGR 1999; Russell et al., JGR 1999 (TARFOX issue)
A Chain of Field Experiments Measuring Aerosols & Their Effects on Atmospheric Radiation ICARTT MILAGRO TARFOX PRiDE ACE-Asia INTEX POLARCAT ACE-2 SAFARI CLAMS AIOP -A -B ARCTAS EVE ADAM ISDAC TAR AR4 Models frozen Simulations complete Models frozen Simulations complete Published Published Radiative flux(l) closure & forcing efficiency(l) Radiative flux closure & forcing efficiency P. Russell, DOE-ASP Meeting, Annapolis, MD, 27 Feb 2008
Climate Change Science in INTEX-A/ICARTT Measurements of Aerosol Effects on the Solar Energy that Drives Climate Forcing Efficiency [W m-2] Solar energy [W m-2] Slope =Aerosol Radiative Forcing Efficiency Case 2,21 Jul2004 Case Jetstream 31 (J31) Aerosol Amount, AOD(499 nm) Redemann et al., JGR, 2006 • Scientific Conclusions • The gradients (spatial variations) in AOD that occur frequently off the US East coast provide a natural laboratory for studying effects of aerosol particles on solar energy, and hence on climate. • For the average aerosol optical depth of ~0.5 in the 10 cases shown above, aerosols on average reduced the incident visible radiation (near midday) by the amount of energy it would take to power one 40 W light bulb for every square meter of ocean surface (0.5 x -80 W m-2 = -40 W m-2; see right frame above). J. Redemann, P. Pilewskie, P. Russell. NASA Ames & U. Colorado
What is the role of field programs in reducing the uncertainty in Aerosol Radiative Forcing? • Improving satellite retrieval algorithms & models by: • Testing satellite data products (validation) • Determining actual aerosol properties • Determining the processes leading to #2 • Measuring aerosol radiative effects & testing closure between measured radiation & aerosol optical & physiochemical properties • Testing models P. Russell, DOE-ASP Meeting, Annapolis, MD, 27 Feb 2008
DC-8 C-130 B200 Kaufman Symposium 30 May-1 June 2007 Greenbelt, MD J31 STARS 1975 TARFOX 1996 INTEX-B 2006
Using measuredDaFlux vs AOD to find best-fit aerosol SSA, w(550 nm) 24-hr avg. DaF¯ (W m-2) Aerosol Optical Depth (300-700 nm) above Measurement Hignett et al., JGR 1999; Russell et al., JGR 1999 (TARFOX issue)
Comparison of Techniques to Determine Aerosol Single Scattering Albedo Russell et al., JGR, 1999b, Bergstrom & Russell, GRL,1999
Comparison of Aerosol Single Scattering Albedos Derived by DiverseTechniques Redemann et al., JGR, 2000b [Russell et al., JAS 2001] P. Russell, DOE-ASP Meeting, Annapolis, MD, 27 Feb 2008
A Chain of Field Experiments Measuring Aerosols & Their Effects on Atmospheric Radiation ICARTT MILAGRO TARFOX PRiDE ACE-Asia AIOP INTEX POLARCAT ACE-2 SAFARI CLAMS -A -B ARCTAS EVE ADAM ISDAC SSA from radiative flux closure SSA(l) from radiative flux closure P. Russell, DOE-ASP Meeting, Annapolis, MD, 27 Feb 2008
Background on Radiative Flux Divergence & Closure, Absorption Spectra, etc. 2000 m Downwelling Flux: F Upwelling Flux: F Net Flux: F- F Flux Divergence (absorption): (F- F)2000m- (F- F)43m Fractional absorption: [(F- F)2000m- (F- F)43m]/ F2000m 43 m P. Russell, DOE-ASP Meeting, Annapolis, MD, 27 Feb 2008
Pilewskie, Bergstrom, Schmid et al. P. Russell, Earth Science Seminar, NASA Ames, 19 July 2007
Aerosol Single Scattering Albedo Spectrum Derived from measured flux and AOD spectra. Desirable features: Describes aerosol in its ambient state (incl volatiles like water, organics, nitrates) Wide l range: UV-Vis-SWIR Includes l range of OMI-UV, OMI-MW, MISR, MODIS, CALIPSO, HSRL, Glory ASP, RSP, POLDER, … Coalbedo (1-SSA) varies by factor 4, l = 350-900 nm Single scattering albedo 12 April 2001, ACE-Asia [Bergstrom, Pilewskie, Schmid et al., JGR 2004] Wavelength, nm P. Russell, DOE-ASP Meeting, Annapolis, MD, 27 Feb 2008
SSA Spectra from 4 Experiments Single Scattering Albedo Wavelength, nm Bergstrom et al., ACP, 2007 P. Russell, Earth Science Seminar, NASA Ames, 19 July 2007
Aerosol Absorption Optical Depth (AAOD) Spectra from 5 Experiments AAE = 1.45 AAOD = K l-AAE 2.27 Absorption Optical Depth 1.05 Absorption Angstrom Exponent (AAE) 2.34 1.12 For Black Carbon, AAE = 1 Wavelength, nm Bergstrom et al., ACP, 2007 P. Russell, Earth Science Seminar, NASA Ames, 19 July 2007
A Chain of Field Experiments Measuring Aerosols & Their Effects on Atmospheric Radiation ICARTT MILAGRO TARFOX PRiDE ACE-Asia AIOP INTEX POLARCAT ACE-2 SAFARI CLAMS -A -B ARCTAS EVE ADAM ISDAC SSA from radiative flux closure SSA(l) from radiative flux closure SSA(l) from in situ SSA(l) from radiative flux closure P. Russell, DOE-ASP Meeting, Annapolis, MD, 27 Feb 2008
Aerosol Optics Pollution Wavelength dependence of absorption over Mexico is linked to both the organic carbon component (AMS - J, Jimenez, P. DeCarlo) and dust. Model and remote sensing implications for SSA etc. { Shortwave Enhancement due to dust Absorption Angstrom Exponent Scattering Angstrom Exponent Trend due to OC mass fraction Expected value for pure BC Dust Shinozuka, Clarke et al., 2007 Organic fraction of non-refractory mass P. Russell, Earth Science Seminar, NASA Ames, 19 July 2007
Additional MILAGRO evidence of enhanced absorption in UV and near-UV: 0 derived from ground-based MFRSR & spectroradiometer measurements Jim Barnard, PNNL Rainer Volkamer, UCSD
¡Sí! [Barnard & Volkamer, MAX-MEX]
Major findings (nuggets): Delayed scattering at Picos Tres Padres indicates secondary organic aerosol formation (Mazzoleni, Dubey) -Mechanism developed by simultaneous measurements and modeling of gas-phase precursors (Herndon et al)Average SSA of surface aerosol at the surface in Mexico City Valley surveyed extensively by the Aerodyne-LAPA is ~0.7 (absorbing), consistent with fresh soot (SSA~0.3) coated by scattering organics (Mazzoleni, Dubey) MILAGRO Breakout Group on Aerosol Optical Properties & Radiative Effects
A Chain of Field Experiments Measuring Aerosols & Their Effects on Atmospheric Radiation ICARTT MILAGRO TARFOX PRiDE ACE-Asia INTEX AIOP POLARCAT ACE-2 SAFARI CLAMS -A -B ARCTAS EVE ADAM ISDAC Chemical apportion-ment of AOD (optical-chemical closure)Importance of organics Size-resolved chemical apportion-ment of AODImportance of organics to submicron AOD P. Russell, DOE-ASP Meeting, Annapolis, MD, 27 Feb 2008
Importance of organics in ACE-Asia: Size-resolved composition 23 Apr 2001 [Wang et al., JGR 2002] P. Russell, DOE-ASP Meeting, Annapolis, MD, 27 Feb 2008
Extinction closure from DOE-ARM AIOP P. Russell, DOE-ASP Meeting, Annapolis, MD, 27 Feb 2008
Comparison of Cadenza and Neph+PSAP Extinction 26 vertical profiles, May 2003 [Schmid,…, Strawa et al., JGR 2006] P. Russell, Earth Science Seminar, NASA Ames, 19 July 2007
Comparison of Cadenza and AATS-14 Extinction profiles27 May 2003 [Strawa et al., JGR 2006] P. Russell, DOE-ASP Meeting, Annapolis, MD, 27 Feb 2008
What is the role of field programs in reducing the uncertainty in Aerosol Radiative Forcing? • Improving satellite retrieval algorithms & models by: • Testing satellite data products (validation) • Determining actual aerosol properties • Determining the processes leading to #2 • Measuring aerosol radiative effects & testing closure between measured radiation & aerosol optical & physiochemical properties • Testing models P. Russell, DOE-ASP Meeting, Annapolis, MD, 27 Feb 2008
Airborne Sunphotometer-Satellite* Comparisons ICARTT MILAGRO TARFOX PRiDE ACE-Asia INTEX POLARCAT ACE-2 SAFARI CLAMS -A -B ARCTAS EVE ADAM ISDAC Satellite Instruments Compared To AATS AODs • ATSR-2 • AVHRR • GMS-5 • GOES-8 • MISR • MAS# • MODIS-Aqua • MODIS-Terra • OMI • RSP# • SeaWiFS • TOMS ~25 journal pubs *Nadir-viewing #Airborne Simulator of Satellite Instrument P. Russell, DOE-ASP Meeting, Annapolis, MD, 27 Feb 2008
AATS-14 NASA Ames Airborne Tracking Sunphotometers (AATS-6 & AATS-14) AATS-6 P. Russell, Earth Science Seminar, NASA Ames, 19 July 2007
Airborne Sunphotometer-Satellite Comparisons Over Ocean ICARTT MILAGRO TARFOX PRiDE ACE-Asia INTEX POLARCAT ACE-2 SAFARI CLAMS -A -B ARCTAS EVE ADAM ISDAC First Tests of SeaWiFS AOD 4-l Algo-rithm First Tests of MODIS AOD at 2 Longest l Over Water First Tests of MODIS Dust Meas Over Water Tests of 2-Angle Space AOD Meas Tests of AVHRR AOD Tests of OMI UV AOD Over Water Tests of MISR AOD over Water Yield Calib. Change Tests of MODIS Glint Limits First 3-Way Compar- ison: MODIS-MISR-AATS Tests of Geostationary (GOES & GMS-5) AOD P. Russell, DOE-ASP Meeting, Annapolis, MD, 27 Feb 2008
The A-Train is a set of satellites that fly in sequence Flying J31 under the A-Train provides opportunity to compare AODs from AATS, MODIS, & OMI
Coordinated satellite, in-situ and radiative measurements in MILAGRO OMI/Aura CALIPSO CloudSat GLORY POLDER/Parasol MODIS/Aqua MISR, MODIS/Terra B200 DC-8 C-130 J31