SPACE-BASED HCHO MEASUREMENTS AS CONSTRAINTS ON VOC EMISSIONS IN ASIA Tzung-May Fu, Daniel J. Jacob Harvard University Kelly V. Chance Harvard SAO/CFA Work supported by NASA Atmospheric Chemistry Modeling and Analysis Program Barbara Barletta, Donald Blake University of California at Irvine Paul I. Palmer University of Leeds

Anthropogenic 40 Tg Streets et al. [2003] Biomass burning 12 Tg Streets et al. [2003] Biogenic 80 Tg MEGAN State-of-the-sciences inventories CTM (GEOS-Chem) GOME Spatial variation Seasonal variation MEGANGOME Over N Am GOME HCHO dominated by biogenic isoprene  Well captured by MEGAN Palmer et al. [2001, 2003, 2005], Abbot et al. [2003]METHODS

Relationship to VOC emissions far more complex than for N. America; biomass burning, isoprene, anthropogenic VOCs, direct HCHO emission all contribute GOME HCHO MONTHLY COLUMNS OVER ASIA ( )

MonthChange95% C. I. DEC+25%+12~37% JAN+32%+17~47% FEB+20%+1~33% Excess winter GOME HCHO due to Chinese anthropogenic short-lived VOCs Percent change to Streets et al. [2003] emissions Chinese grids w/ GOME > 0 Reduced major axis linear regression

CHINESE URBAN MEASUREMENTS Urban air sampled in 43 Chinese cities in Jan and Feb 2001 [Barletta et al., 2005] Local Inventory E VOC / E C3H8 OBS [VOC] / [C 3 H 8 ] Inventory underestimates pentane, ethyne, xylenes  underestimates vehicular emission  9% HCHO Enhanced primary HCHO emission from vehicles  +10~60% HCHO

HCHO SEASONAL VARIATION GOME GEOS-Chem Biogenic Biomass x 2 Anthropogenic x 2 Model bkgd HCHO vertical column [10 16 molec/cm2] GOME – Model background =  1 x biogenic +  2 biomass r 2 = 0.80 ~ 0.93

MEGAN 31 TgC GOME 27 TgC GEIA 37 TgC BIOGENIC ISOPRENE EMISSION Higher emission by the deciduous broadleaf forests in China Lower emission by the evergreen broadleaf forests in SE Asia & Indonesia Scaling factors GOME vs MEGAN

Streets et al TgC GOME 1.7 TgC BIOMASS BURMING HCHO EMISSION Scaling factors GOME vs Streets 3x EF 30~70% residual

SUMMARY Model 132 Tg/yrGOME 137 Tg/yr Spatial and seasonal variation of HCHO column can be use to constrain anthropogenic, biomass burning, and biogenic VOC emissions Previously unrecognized burning associated with winter wheat harvesting in June over North China Plains, equivalent to 30% to 70% percent of crop residual burned in field Total NMVOC