An International Flare for Modeling
Atmospheric scientist Bhupesh Adhikary has participated in numerous NASA
field missions. But the summer deployment of the NASA's ARCTAS mission
afforded the modeler his first chance to fly on the mission's airborne
science laboratory and watch his 3-D atmospheric models in action.
In June and July 2008, Adhikary was one of more than 100 scientists from
around the world who gathered in Cold Lake, Alberta for the Arctic Research
of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS)
mission. For more than two weeks, researchers made near-daily flights aboard
aircraft loaded with instruments to collect atmospheric data through and
downwind of smoke plumes from Canadian forest fires. The results are
expected to help researchers characterize the smoke plumes' chemistry,
physical properties and impact on the atmosphere in the Arctic.
Modelers onsite helped researchers plan flight paths through and downwind of
smoke plumes in a pattern that would maximize measurements in line with the
mission's science goals. Adhikary, a Ph.D. student at the University of
Iowa, Iowa City, used a computer model that could forecast the movement of
various emissions including carbon monoxide, which can be used to track the
emissions of fires.
The computer model was created in the 1970s by Adhikary's Ph.D. advisor,
Gregory Carmichael of the University of Iowa. Since the model's inception,
many people including Adhikary have contributed to its development by
incorporating new atmospheric findings that continue to refine and improve
the model's accuracy.
An advantage of modeling is that Adhikary can work from nearly anywhere,
whether it's his hometown in Nepal or in the remote Cold Lake, Alberta, as
long as he has a computer and an Internet connection.
Every morning during the mission, Adhikary looked at the new updated
forecast and presented a summary slide. "All of the modelers did this and
then we would come up with a consensus based on differences and similarities
between them to determine the best location for the airplanes to fly," he
The results, in turn, will help modelers fine-tune their models. "The models
are uncertain, so we like these campaigns so we can improve our models based
on observations -- see how well our model predicted versus what was
observed," Adhikary said.
Adhikary's venture into the field provided a first-hand look at how his
"When I was onboard looking at my model products and then seeing out the
window, I could look at where my model placed the plumes and compare that to
where they actually were. It gave me a better feel of what my model was
doing, which was interesting -- the eight-hour flight didn't seem that long
to me at all," Adhikary said.
What Adhikary saw in the field countered his expectations going into the
mission. "I was expecting emissions from Canadian fires to just dominate
everything," he said. But in addition to emissions measured from Canadian
forest fires -- most started by lightning -- measurements turned up natural
and human-caused pollution from California and Asia, mixed throughout the
atmosphere from very low altitude up to about 6 miles.
Still, Adhikary knows that pollution, like weather, is oblivious to
geographical borders. "When I model I'm looking at Asia, North America and
Europe, so it gives an international flare to the work, which is very
important to me," he said.
"In Nepal, we don't have the infrastructure that is needed to do modeling,
but now computers are getting cheaper and when I graduate I hope to go back
and start there what I'm doing here," he said. "We don't have a chemical
engineering or an atmospheric science department, so that's the charm of
going back -- I would like to go and try it out, see if I can build
collaborations to stay involved with this type of field mission from afar
and at the same time help Nepal."
NASA's Goddard Space Flight Center