BSOA workshopAugust 2008

NOx-mediated Chemistry - Climate Interactions via Atmospheric Aerosols

Julie Fry, currently unemployed!(was UC Berkeley, starting at Reed College next week)

NO3 + VOCs

RONO2

aerosol

NOx Climate effects?

NO + oxyRO2

RONO2(g)

-Chamber studies of SOA formation-AMS organic nitrate standard studies-Modeling regional importance of NOx-mediated SOA formation-Future: Measuring aerosol chemical composition with Hi-Vol samplers &

offline GC-MS, FTIR, NMR; regional modeling (WRF-Chem)

BSOA workshop

March 13, 2008

NO3 in Juelich SAPHIR chamber, June 2007

NO3 TD-LIF

NO

2 TD

-LIF

inlets

BSOA workshop

o N2O5 +NO3

+ β-pineneΔ aerosol

DRY

60% RH

Y~50%

Y~50%

aerosol formation

HC

MY aero

BSOA workshop

Absorptive partitioning model requires Pvap = 4x10-6 Torr

O2NO OH

estimated Pvap~6x10-4 Torr

Modeling nitrate partitioning

BSOA workshop

Modeling NO3 + β-pinene

Yield(Alkyl nitrates) = 30%

BSOA workshop

How much aerosol could NO3 + β-pinene make globally?

• Mass yield of aerosol from NO3 + β-pinene: ~50%

• Global annual β-pinene emissions: ~ 33 Tg yr-1

• Fraction of β-pinene that reacts with NO3, based on relative NO3, O3, and OH lifetimes: ~ 30%

→ .3 x .5 x 33 Tg yr-1 = 5 Tg yr-1

SOA source estimates: Kanakidou et al, 2005: 12 – 70 Tg year-1

Goldstein & Galbally, 2007: 510 – 910 Tg year-1