Alex Guenther talks with
ScienceWatch.com and answers a few questions about
this month's Fast Moving Front in the field of
Article: Estimates of global terrestrial isoprene
emissions using MEGAN (Model of Emissions of Gases and
Aerosols from Nature) Authors: Guenther,
A;Karl, T;Harley, P;Wiedinmyer, C;Palmer, PI;Geron, C
Journal: ATMOS CHEM PHYS, 6: 3181-3210 AUG 2 2006
Addresses: Natl Ctr Atmospher Res, Div Atmospher Chem, 1850
Table Mesa Dr, Boulder, CO 80305 USA.
Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO
Univ Leeds, Sch Earth & Environm, Leeds LS2 9JT, W
US EPA, Natl Risk Management Res Lab, Res Triangle Pk, NC
Why do you think your paper is highly cited?
Does it describe a new discovery, methodology, or synthesis of
The accurate characterization of isoprene emissions and their response to a
changing earth system is a difficult challenge. There are physical,
chemical, and biological controlling factors that operate on scales ranging
from individual cells to plant canopies and the global earth system. The
paper describes a model, called MEGAN, which integrates knowledge from
plant physiology, biochemistry, genomics, ecology, analytical chemistry,
micrometeorology, atmospheric chemistry, and other scientific disciplines.
The model is used by observational scientists, to interpret field
measurements, as well as regional regulatory modelers and global earth
system modelers. This results in a large community with interest in
isoprene emissions and their response to a changing earth system. It is
both a synthesis of knowledge and a description of a methodology.
Would you summarize the significance of your paper
in layman's terms?
"Isoprene and other biogenic
emissions are a key input for the air quality
models that are used to develop regulatory
strategies for controlling regional ozone and
Isoprene is a volatile hydrocarbon produced by vegetation and emitted into
the atmosphere where it can have a major role in determining distributions
of pollutants and climate-relevant atmospheric constituents. On the global
scale, isoprene emissions from vegetation greatly exceed that of total
anthropogenic hydrocarbon emissions.
The paper describes an approach for incorporating isoprene emissions into
quantitative models that attempt to describe the functioning of the earth
system, and for assessments of air quality and climate. These emissions are
highly sensitive to changes in land use, climate and ecosystem stress; it
is critical that they be quantified as accurately as possible.
How did you become involved in this research and
were any particular problems encountered along the way?
This research allowed me to combine my interests in biology,
micrometeorology, and atmospheric chemistry. It is often challenging to
find funding for work that crosses disciplinary boundaries and it is also
difficult to bring together the wide range of expertise required to tackle
some interdisciplinary research topics.
Where do you see your research leading in the
The next step in this research is to use airborne flux systems to directly
measure isoprene emissions on the scales used in regional and global models
and to provide empirical evidence of the role of isoprene in earth system
interactions and feedback couplings. There is also much to be learned about
the biological controls over the response of biogenic emissions to stress
and other changes in the earth system.
Do you foresee any social or political implications
for your research?
Isoprene and other biogenic emissions are a key input for the air quality
models that are used to develop regulatory strategies for controlling
regional ozone and particle pollution. These biogenic compounds establish
the background conditions that are the starting point for determining air
pollution management strategies. Errors in estimates of these emissions
could impact regulatory decisions that have important implications for
human and ecosystem health and financial implications for many industries.
Alex Guenther, Ph.D.
Senior Scientist and Section Head
National Center for Atmospheric Research
Boulder, CO, USA Web