biogenic, pryogenic, anthropogenic pryogenic anthropogenic biogenic anthropogenic pryogenic pyrogenic anthropogenic biogenic anthropogenic Thomas Kurosu, Harvard-Smithsonian HCHO August 2006 Ozone Monitoring Experiment Using space-based measurements of formaldehyde to learn about BVOC distributions Paul Palmer, University of Edinburgh

Environmental factors: temperature solar irradiance leaf area index leaf age July 2003 MEGAN Isoprene Emission Inventory

Global Ozone Monitoring Experiment (GOME) & the Ozone Monitoring Instrument (OMI) GOME (European), OMI (Finnish/USA) are nadir SBUV instruments Ground pixel (nadir): 320 x 40 km2 (GOME), 13 x 24 km2 (OMI) desc (GOME), asc (OMI) cross-equator time GOME: 3 viewing angles  global coverage within 3 days OMI: 60 across-track pixels  daily global coverage O3, NO2, BrO, OClO, SO2, HCHO, H2O, cloud properties Launched in 2004 GOME

GOME HCHO columns July 2001 [10 16 molec cm -2 ] Biogenic emissions Biomass burning * Columns fitted: nm * Fitting uncertainty < continental signals Data: c/o Chance et al – fractionally cloudy pixels (>40%) removed

Relating HCHO Columns to VOC Emissions VOC HCHO hours OH hours h, OH Local linear relationship between HCHO and E k HCHO E VOC =  (k VOC Y VOC  HCHO )  HCHO ___________ VOC source Distance downwind  HCHO Isoprene  -pinene propane 100 km E VOC :  HCHO from GEOS-CHEM CTM and MEGAN isoprene emission model Palmer et al, JGR, Net

MCM HCHO yield calculations Cumulative HCHO yield [per C]  pinene (  pinene similar) DAYS 0.4 Isoprene HOURS 0.5 NO x = 1 ppb NO x = 0.1 ppb Parameterization (1 ST -order decay) of HCHO production from monoterpenes in global 3-D CTM Higher CH 3 COCH 3 yield from monoterpene oxidation  delayed (and smeared) HCHO production Palmer et al, JGR, C 5 H 8 +OH  (i) RO 2 +NO  HCHO, MVK, MACR (ii) RO 2 +HO 2  ROOH ROOH  recycle RO and RO 2

GOME Isoprene Emissions: MayJunJulAugSep [10 12 molecules cm -2 s -1 ] Palmer et al, JGR, 2006.

Surface temperature explains 80% of GOME- observed variation in HCHO NCEP Surface Temperature [K] GOME Isoprene Emissions [10 12 atoms C cm -2 s -1 ] G98 fitted to GOME data G98 Modeled curves Time to revise model parameterizations of isoprene emissions? Palmer et al, JGR, 2006.

Tropical ecosystems represent 75% of biogenic NMVOC emissions What drives observed variability of tropical BVOC emissions?

Slant Column HCHO [10 16 molec cm -2 ] Sep 1997 Nov X = Active Fire (ATSR) Monthly ATSR Firecounts Day of Year Significant pyrogenic HCHO source over tropics Good: Additional trace gas measurement of biomass burning; effect can be identified largely by firecounts (see below) Bad: Observed HCHO a mixture of biogenic and pyrogenic – difficult to separate without better temporal and spatial resolution GOME

HCHO and Isoprene over the Amazon In situ isoprene 2002 Trostdorf et al, GOME ATSR Firecounts used to remove HCHO from fires

Isoprene Limonene Beta-pinene [ppb] Time of Day C/o J. Kesselmeier C/o J. Saxton A. Lewis Amazon Africa Can isoprene explain the observed magnitude and variance of HCHO columns over the tropics?

May Jun Jul Aug Sep Oct OMI gives a better chance of estimating African BVOCs OMI Data c/o Thomas Kurosu; horizontal resolution O(10x25 km 2 )

Isoprene concentrations during AMMA July 2006 measured by the Bae146 aircraft; MODIS tree cover overlaid Isoprene data c/o Jim Hopkins and Ally Lewis, U. York Jul OMI [ppt] ATSR Firecounts Jul

“Normal” airmass flow Stagnant airmass flow Jul29-Jul31-Jul 2-Aug 4-Aug 6-Aug8-Aug 10-Aug 12-Aug 14-Aug 16-Aug 18-Aug20-Aug22-Aug24-Aug26-Aug28-Aug30-Aug Temperature (C) Isoprene (ppt) Estimated up to 700 extra deaths attributable to air pollution (O 3 and PM10) in UK during this period O 3 > 100 ppb on 6 consecutive days 2pm, 6 th Aug, 2003 Compiled from UK ozone network data Isoprene c/o Ally Lewis An increasing role for BVOCs in UK air quality?

Stewart et al, 2003 Isoprene Monoterpenes BVOC fluxes for a “hot, sunny” day [molec cm -2 ] OMI HCHO 2<0.3 Bottom-up emission inventory “Expect harmful levels of ozone and PM2.5 over the next couple of days; please keep small children and animals inside. Transatlantic pollution represents 20% of today’s UK surface ozone.” 2010 Satellite observations test bottom-up emission inventories used for air quality: an important step toward regional chemical weather forecasting

Final Comments Proper interpretation of HCHO requires an integrated approach, i.e., including surface data, lab data Interpreting space-based HCHO data is still in its infancy – new instruments bring better resolution but also new challenges With the frequency of European heatwaves projected to increase the role of BVOCs in future UK air quality must be better quantified