4 th geos-chem users’ meeting
DESCRIPTION
4 th GEOS-Chem Users’ Meeting. Aerosol Optical Thickness. Cloud Fraction and Liquid Water Path. Kaufman et al., Nature, 2002. Bennartz , JGR, 2006. Effect of Oceanic Organic Carbon Emissions on the Growth of Secondary Particles and Global CCN Abundance. Gan Luo and Fangqun Yu - PowerPoint PPT PresentationTRANSCRIPT
4th GEOS-Chem Users’ Meeting
Effect of Oceanic Organic Carbon Emissions on the Growth of Secondary Particles and Global CCN Abundance
Effect of Oceanic Organic Carbon Emissions on the Growth of Secondary Particles and Global CCN Abundance
Gan Luo and Fangqun Yu
ASRC, SUNY-Albany, 2009-04-07
Kaufman et al., Nature, 2002 Bennartz, JGR, 2006Aerosol Optical Thickness Cloud Fraction and Liquid Water Path
IntroductionSOA, formed from the oxidation of phytoplankton-produced isoprene, can affect chemical composition of marine CCN - Meskhidze and Nenes, Science, 2006
Marine organic aerosol: 75TgC/yr (Roelofs, ACP, 2008)Primary OC: 35~50TgC/yr; SOA produced by isoprene: 25~40 TgC/yr
Marine organic aerosol: 8TgC/yr (Spracklen et al., GRL, 2008)
Marine isoprene: in-situ 0.19TgC/yr (Broadgate et al, GRL, 1997); satellite 0.1TgC/yr (Palmer and Shaw, GRL, 2005); model 0.3~1.9TgC/yr (Arnold et al, ACP, 2009)
Large uncertainty of marine organic carbon emission
Observed α-pinene and isoprene over Southern Ocean - Yassaa et al., Environ. Chem., 2008
GEOS-Chem
Meteorology: GEOS-5, 4º×5º, 47 Layers
Emission: EDGAR+EPA/LNEI99+BRAVO+EMEP+STREETS+GFED2
Chemistry: photochemistry + online aerosol chemistry
Aerosol microphysics: Advanced Particle Microphysics
Marine emission of α-pinene and isoprene :
The emission scheme is based on chlorophyll concentration and 10 m wind speed
C is Chlorophyll from combined MODIS/SeaWiFS
2
12 2 2 110 103.0 10 0.24 0.061 , :pinene m m COF C W W Sc Sc unit kg m s
2
13 2 2 110 101.8 10 0.24 0.061 , :isoprene m m COF C W W Sc Sc unit kg m s
Yassaa et al., Environ. Chem., 2008
Compare with Ship Measurement
Shipboard measurements:1-20-2007 ~ 2-5-2007
OOMPH (Organics over the Ocean Modifying Particles in both Hemispheres) summer cruise in the Southern Ocean
GEOS-Chem
simulated daily averageof α-pinene and isoprene along the shipping route during the same period
Model simulation can capture the major variation of the two species
A
B
C
A
B
C
Global Distributions at Surface
127TgC/Yr 602TgC/Yr
127+35TgC/Yr 602+2.1TgC/Yr
Impact on Organic Chemistry Relative change Zonal average
Impact on Sulfur Chemistry Relative change Zonal average
Impact on CCN Abundance Relative change Zonal average
Summary
Marine α-pinene and isoprene emissions and the impacts on chemistry and aerosols have been simulated with GEOS-Chem
Marine emission:
α-pinene: 35TgC/yr, isoprene: 2.1TgC/yr
Marine α-pinene emission can increase SOA mass by up to 60% in the lower troposphere of Southern Hemisphere (40ºS-90ºS). It decreases OH concentration in the region by 1~10%. The associated changes in SO2 and H2SO4 concentrations result in an increase of nucleation rate over Antarctica by up to 10%, and total CCN over Antarctica enhanced by 3~5%
The impact of marine isoprene emission is small
The End
Acknowledgments:Funding support from NASA, NOAA, and NSF