Aerosol direct radiative effects over the northwest Atlantic, northwest Pacific, and North Indian Oceans: estimates based on in-situ chemical and optical measurements and chemical transport modeling

• Main Authors: Bates, T. S., Anderson, T. L., Baynard, T., Bond, T., Boucher, O., Carmichael, G., Clarke, A., Erlick, C., Guo, H., Horowitz, L., Howell, S., Kulkarni, S., Maring, H., Mccomiskey, A., Middlebrook, A., Noone, K., O'Dowd, C. D., Ogren, J., Penner, J., Quinn, P. K., Ravishankara, A. R., Savoie, D. L., Schwartz, S. E., Shinozuka, Y., Tang, Y., Weber, R. J., Wu, Y.
• Other Authors: NOAA Pacific Marine Environmental Laboratory Seattle (PMEL), National Oceanic and Atmospheric Administration (NOAA), Department of Atmospheric Sciences Seattle, University of Washington Seattle, NOAA Aeronomy Laboratory, Civil and Environmental Engineering Illinois (CEE), University of Illinois at Urbana-Champaign Urbana, University of Illinois System-University of Illinois System, Climate, Chemistry and Ecosystems Team Exeter, United Kingdom Met Office Exeter, Center for Global and Regional Environmental Research (CGRER), University of Iowa Iowa City, Department of Oceanography, University of Hawaii, Fredy and Nadine Herrmann Institute of Earth Sciences, The Hebrew University of Jerusalem (HUJ), Department of Atmospheric, Oceanic, and Space Sciences Ann Arbor (AOSS), University of Michigan Ann Arbor, University of Michigan System-University of Michigan System, NOAA Geophysical Fluid Dynamics Laboratory (GFDL), Radiation Science Program, NASA Headquarters, NOAA Climate Monitoring and Diagnostics Laboratory (CMDL), International Geosphere Biosphere Program, Department of Experimental Physics and Environmental Change Institute, National University of Ireland Galway (NUI Galway), Rosenstiel School of Marine and Atmospheric Science (RSMAS), University of Miami Coral Gables, Environmental Sciences Department, Brookhaven National Laboratory Upton, NY (BNL), U.S. Department of Energy Washington (DOE)-UT-Battelle, LLC-Stony Brook University SUNY (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy Washington (DOE)-UT-Battelle, LLC-Stony Brook University SUNY (SBU), State University of New York (SUNY)-State University of New York (SUNY), School of Earth and Atmospheric Sciences Atlanta, Georgia Institute of Technology Atlanta
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2006
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; Indian; Pacific; Northwest Atlantic
• Online Access: https://hal.archives-ouvertes.fr/hal-00300924; https://hal.archives-ouvertes.fr/hal-00300924/document; https://hal.archives-ouvertes.fr/hal-00300924/file/acpd-6-175-2006.pdf

International audience The largest uncertainty in the radiative forcing of climate change over the industrial era is that due to aerosols, a substantial fraction of which is the uncertainty associated with scattering and absorption of shortwave (solar) radiation by anthropogenic aerosols in cloud-free conditions (IPCC, 2001). Quantifying and reducing the uncertainty in aerosol influences on climate is critical to understanding climate change over the industrial period and to improving predictions of future climate change for assumed emission scenarios. Measurements of aerosol properties during major field campaigns in several regions of the globe during the past decade are contributing to an enhanced understanding of atmospheric aerosols and their effects on light scattering and climate. The present study, which focuses on three regions downwind of major urban/population centers (North Indian Ocean (NIO) during INDOEX, the Northwest Pacific Ocean (NWP) during ACE-Asia, and the Northwest Atlantic Ocean (NWA) during ICARTT), incorporates understanding gained from field observations of aerosol distributions and properties into calculations of perturbations in radiative fluxes due to these aerosols. This study evaluates the current state of observations and of two chemical transport models (STEM and MOZART). Measurements of burdens, extinction optical depth (AOD), and direct radiative effect of aerosols (DRE ? change in radiative flux due to total aerosols) are used as measurement-model check points to assess uncertainties. In-situ measured and remotely sensed aerosol properties for each region (mixing state, mass scattering efficiency, single scattering albedo, and angular scattering properties and their dependences on relative humidity) are used as input parameters to two radiative transfer models (GFDL and University of Michigan) to constrain estimates of aerosol radiative effects, with uncertainties in each step propagated through the analysis. Constraining the radiative transfer calculations by observational ...