What satellite and aircraft observations can tell us about the organic aerosol budget

What satellite and aircraft observations can tell us about the organic aerosol budget

Colette L. Heald

5th International GEOS-Chem MeetingMay 2, 2011

Acknowledgments: David Ridley, Easan Drury, Sonia Kreidenweis,

Hugh Coe, Matthew Jolleys, Jose Jimenez, Rodney Weber, Roya Bahreini, Ann Middlebrook, Lynn Russell, Armin Wisthaler, Thomas Karl, Jennifer Murphy, Joost de Gouw, Carsten Warneke

FIRST… SOME INTRODUCTIONS

Bonne Ford, graduate studentPoster: Tuesday

Luke Schiferl, graduate student

Kateryna Lapina, PostdocTalk: next!

Dave Ridley, PostdocTalk: after lunch

Maria Val MartinResearch Scientist

just joined group!

CAN SATELLITE OBSERVATIONS SHED ANY LIGHT ON THE BUDGET OF OA?

SURFACE REFLECTANCE

Bottom-up calculations suggest that SOA source may be anywhere from 140-910 TgC/yr [Goldstein and Galbally, 2007].

topz

0

AOD= α RH z M z dz

Organicaerosol

Sulfate Dust

Sea SaltNitrate

SATELLITE AOD

Assumptions:Optical PropertiesSize Distributions

Aerosol Distributions

AEROSOL SPECIATED MASS CONCENTRATIONS

Soot

ATTRIBUTE ENTIRE MODEL UNDERESTIMATE OF AOD TO ORGANICS

Estimate that ~150 TgC/yr source is required to close the

MISR-GEOS-Chem* discrepancy.

DJF JJA

MISR

GEOS-Chem*

MISR-GEOS-Chem*

*excluding OA (v8-02-04)

This is more than THREE TIMES what is currently included in global models….

BUT at the low end of Goldstein & Gallbally [2007] range.

HAVE WE REDUCED THE UNCERTAINTY ON THE OA BUDGET?

910

47 Existing GEOS-Chem sources

140 Our satellite top-down estimate 150

Range estimated

by: Goldstein

and Galbally [2007]

All units in TgCyr-1

[Heald et al., 2010]

DIGGING IN DEEPER: 17 AIRCRAFT FIELD CAMPAIGNS

* All AMS measurements, except ITCT-2K4 (PILS) and ACE-Asia (filters).

2001-2009

Aircraft constraints on the organic aerosol distribution through depth of troposphere in remote, polluted and fire influenced regions.

COMPARISON OF VERTICAL PROFILE

GEOS-Chem: v8-03-01 with GEOS-5 met product (GEOS-4 for ACE-Asia only), simulations matched to year and location of aircraft, standard POA, BSOA and ASOA.

OVERALL COMPARISON OF OA SIMULATION

In median observations range from 0.45-4.5 of simulated. Difference is largest close to source.

CAN WE ATTRIBUTE THE MODEL

UNDERESTIMATE?

Adding ~100 Tg/yr source of ASOA (as suggested by Spracklen et al., 2011)

improves comparison in polluted regions, but leads to too much OA aloft and in

remote regions.OA sink?

Higher volatility OA?

[Heald et al., in prep]