Chapter 29
Model of Emissions of Gases and Aerosol
from Nature Version 3 (MEGAN3)
for Estimating Biogenic Emissions
Alex Guenther, Xiaoyan Jiang, Tejas Shah, Ling Huang, Sue Kemball-Cook
and Greg Yarwood
Abstract Biogenic volatile organic compound (BVOC) emissions from terrestrial
ecosystems drive distributions of several atmospheric constituents relevant to air
quality and climate. BVOC emission rates can vary more than an order of magnitude
over spatial scales of a few kilometers and time scales of less than a day which
makes estimation of these emissions especially challenging. New improvements to
the Model of Emission of Gases and Aerosols from Nature (MEGAN version 3) are
described including (1) a transparent approach for assigning emission factors and
other model parameters, (2) updated emission factors and algorithms based on recent
measurements, and (3) treatments for previously unrepresented processes including
stress induced emissions and canopy heterogeneity. The estimated emissions are
compared to alternative model approaches and evaluated with aircraft measurements
of concentrations and fluxes. Remaining gaps and priorities for future progress in
biogenic organic emission modeling are also discussed.
29.1 Introduction
The overall goal of this study was to improve numerical model predictions of regional
ozone and aerosol distributions by reducing uncertainties associated with quantitaA. Guenther · X. Jiang
Department of Earth System Science, University of California, Irvine, CA 92697, USA
e-mail: alex.guenther@uci.edu
X. Jiang
e-mail: jiang.ut@gmail.com
T. Shah · L. Huang · S. Kemball-Cook · G. Yarwood (B)
Ramboll, 7250 Redwood Boulevard Suite 105, Novato, CA 94945, USA
e-mail: GYarwood@ramboll.com
T. Shah
e-mail: TShah@ramboll.com
S. Kemball-Cook
e-mail: SKemballCook@ramboll.com
© Springer Nature Switzerland AG 2020
C. Mensink et al. (eds.), Air Pollution Modeling and its Application XXVI,
Springer Proceedings in Complexity,
https://doi.org/10.1007/978-3-030-22055-6_29
187
Model of Emissions of Gases and Aerosol
from Nature Version 3 (MEGAN3)
for Estimating Biogenic Emissions
Alex Guenther, Xiaoyan Jiang, Tejas Shah, Ling Huang, Sue Kemball-Cook
and Greg Yarwood
Abstract Biogenic volatile organic compound (BVOC) emissions from terrestrial
ecosystems drive distributions of several atmospheric constituents relevant to air
quality and climate. BVOC emission rates can vary more than an order of magnitude
over spatial scales of a few kilometers and time scales of less than a day which
makes estimation of these emissions especially challenging. New improvements to
the Model of Emission of Gases and Aerosols from Nature (MEGAN version 3) are
described including (1) a transparent approach for assigning emission factors and
other model parameters, (2) updated emission factors and algorithms based on recent
measurements, and (3) treatments for previously unrepresented processes including
stress induced emissions and canopy heterogeneity. The estimated emissions are
compared to alternative model approaches and evaluated with aircraft measurements
of concentrations and fluxes. Remaining gaps and priorities for future progress in
biogenic organic emission modeling are also discussed.
29.1 Introduction
The overall goal of this study was to improve numerical model predictions of regional
ozone and aerosol distributions by reducing uncertainties associated with quantitaA. Guenther · X. Jiang
Department of Earth System Science, University of California, Irvine, CA 92697, USA
e-mail: alex.guenther@uci.edu
X. Jiang
e-mail: jiang.ut@gmail.com
T. Shah · L. Huang · S. Kemball-Cook · G. Yarwood (B)
Ramboll, 7250 Redwood Boulevard Suite 105, Novato, CA 94945, USA
e-mail: GYarwood@ramboll.com
T. Shah
e-mail: TShah@ramboll.com
S. Kemball-Cook
e-mail: SKemballCook@ramboll.com
© Springer Nature Switzerland AG 2020
C. Mensink et al. (eds.), Air Pollution Modeling and its Application XXVI,
Springer Proceedings in Complexity,
https://doi.org/10.1007/978-3-030-22055-6_29
187