Using satellite observations of HCHO column to better understand natural NMVOC emission processes Paul Palmer, Dorian Abbot, May Fu, Daniel Jacob, Bill Munger, Kelly Chance, Alex Guenther, Mike Pilling, Jenny Stanton, Shelley Pressley, Brian Lamb & Hal Westberg

What do we (don’t we) know about biogenic emissions? What can satellites provide? Global 3d chemistry transport model

Modeling Overview GEOS-CHEM Global 3D CTM PAR, T Emissions MEGAN (isoprene) Canopy model Leaf age LAI Temperature Base factors MODEL BIOSPHERE GEIA Monoterpenes MBO Acetone Methanol Monthly mean AVHRR LAI

Isoprene emissions – July 1996 GEIA BEIS2 MEGAN GOME 7.1 Tg C 2.6 Tg C 3.6 Tg C 5.7 Tg C [1012 atom C cm-2 s-1]

MCM HCHO yield calculations Isoprene HOURS 0.5 NOx = 1 ppb NOx = 0.1 ppb Used to parameterize (1ST-order decay) HCHO production from monoterpenes in GEOS-CHEM Cumulative HCHO yield [per C]  pinene DAYS 0.4  pinene DAYS

Column HCHO Observations of the 2001 North American Growing Season GEOS-CHEM (MEGAN) GOME GEOS-CHEM (MEGAN) GOME MAY AUG r=0.71 r=0.75 r=0.76 r=0.58 r=0.46 JUN SEP Model bias over southeastern US: May -20% Jun -38% Jul -27% Aug -5% Sep +33% -0.5 2.5 0.5 1.5 JUL [1016 molecules cm-2]

[1012 molecules cm-2s-1] [1016 molecules cm-2] -0.5 2.5 0.5 1.5 0.0 (MEGAN) HCHO GOME HCHO MEGAN ISOP MONOTERPENES MAY JUN JUL AUG SEP r=0.71 r=0.75 [1016 molecules cm-2] [1012 molecules cm-2s-1] r=0.76 Biogenic emissions – isoprene, monoterpenes, mbo 10^12 molec emissions flux (mol/cm2/s) 1 - model/obs hcho 2 - model hcho/iso 3 - obs hcho /iso 4 - model hcho/mono 5 - obs hcho/mono MONTH 0 0.604888 0.718397 0.394572 0.372859 0.0877433 1 0.685620 0.802162 0.519447 0.334138 0.290748 2 0.776744 0.825631 0.625764 0.334617 0.419762 3 0.675475 0.857021 0.503723 0.352030 0.166631 4 0.387514 0.756604 0.185818 0.371239 -0.146963 r=0.58 r=0.46 -0.5 2.5 0.5 1.5 0.0 6.0 0.0 1.5

Relating HCHO Columns to VOC Emissions hours OH h, OH kHCHO HCHO EVOC = _______________ kVOCYieldVOCHCHO VOC source Distance downwind WHCHO Isoprene a-pinene propane 100 km

Isoprene Emissions during the 2001 Growing Season MEGAN GOME MAY JUN JUL AUG SEP r = 0.63 Isoprene Emissions during the 2001 Growing Season r = 0.59 r = 0.44 Biogenic emissions – isoprene, monoterpenes, mbo 10^12 molec emissions flux (mol/cm2/s) Correlation( r ) 0.63 0.59 0.44 0.46 0.27 r = 0.46 5 10 [1012 molecules cm-2s-1] r = 0.27

PROPHET (MI) DAYS 2K1 MEGAN isop flux (10-12LT) Measured isop flux (10-12LT) GEOS-CHEM (MEGAN) HCHO column GOME HCHO column PROPHET (MI) C/o Shelley Pressley et al GOME uncertainty Errors from 1) fitting 4x10^15 2) pacific bias correction 1x10^15 3) AMF – albedo, boundary layer depths, clouds and aerosols - 30% + 15% + 30% = 45% in quadrature. Values of monthly mean values range 1e16 – 2.5e16 = 0.8e16 DAYS 2K1

Surface air temperature [K] GOME Isoprene “volcano” GEOS-CHEM Surface air temperature [K] Slant column HCHO [1016 mol cm-2] Modeled temperature dependence of isoprene emission Estimation of model parameters July 7 1996 ? July 20 1996 [1016 molec cm-2] mm