Scientists repeatedly check the weather forecasts as they prepare aircraft for flight and perform last-minute checks on science instruments. There’s a large winter storm rolling in, but that’s exactly what these storm-chasing scientists are hoping for.
The team is tracking storms across the Midwest and
Eastern United States in two NASA planes equipped with scientific instruments
to help understand the inner workings of winter storms as they form and
develop. The team is flying two aircraft to investigate winter storms, one
above the storm and one within the clouds. Each is equipped with a suite of
scientific instruments to collect data about snow particles and the conditions
in which they form. The experiments are part of the second deployment of NASA’s
Investigation of Microphysics and Precipitation for Atlantic Coast-Threatening
Storms (IMPACTS) mission, which began in January and is planned to wrap up at the end
of February.
This data will help the team relate properties of the
snow particles and their environment to large-scale processes – such as the
structure of clouds and precipitation patterns – that can be seen with remote
sensing instruments on aircraft and satellites. Ultimately, what the IMPACTS
team learns about snowstorms will improve meteorological models and our ability
to use satellite data to predict how much snow will fall and where.
On Jan. 4, 2022, the
MODIS instrument aboard NASA’s Terra satellite captured this image of snowfall
after a large storm dumped wet, heavy snow across the Mid-Atlantic region of
the United States. Some areas accumulated over 14 inches, shutting down
businesses, schools, and interstate highways. Credits:
NASA
Surveying a Variety of Storms
Storms often form narrow structures called snow bands, said Lynn McMurdie,
principal investigator for IMPACTS and an atmospheric scientist at the
University of Washington in Seattle. One of the main goals of IMPACTS is to
understand how these structures form, why some storms don’t have snow bands,
and how snow bands can be used to predict snowfall. To do this, the team hopes
to sample a wide variety of storms throughout the three-year IMPACTS campaign.
During the 2020 IMPACTS
campaign, the team sampled a variety of storms in the Midwest
and East Coast, including warmer rainstorms and storms with strong cold fronts
and convection. But McMurdie says the team didn’t see a Nor’easter, a storm
with a strong low-pressure system that moves up the New England coast and mixes
moisture from the Atlantic Ocean with cold air from Canada.
Nor’easters come up the East Coast and can dump several feet of snow, effectively
shutting down cities, said John Yorks, one of the deputy principal
investigators for IMPACTS at NASA’s Goddard Space Flight Center in Greenbelt,
Maryland. Being better able to predict where these storms will bring snow and
how much could help cities better prepare for severe winter weather.
NASA’s ER-2, a high-altitude jet equipped with a suite of science instruments, takes off. Credits: NASA’s Armstrong Flight Research Center
Above, Below and Into the Clouds
NASA and its partners have several satellites that measure precipitation
from space, such as the Global
Precipitation Measurement mission that observes rain and snow
around most of the world every three hours. “But satellites can’t tell us a lot
about the particles – the actual snowflakes – and where they form within the
clouds,” said Gerry Heymsfield, one of the deputy principal investigators for
IMPACTS at Goddard. IMPACTS is run out of NASA’s Wallops Flight Facility in
Virginia, which is managed by Goddard.
Instead, IMPACTS is flying two aircraft outfitted with scientific
instruments. The NASA Armstrong Flight Research Center’s ER-2, a high-altitude jet
flying out of the Pope Army Airfield near Fayetteville, North Carolina, will
fly at about 65,000 feet to get a top-down view from above the clouds. The
instruments aboard the ER-2 are similar to those on satellites but with higher
spatial resolution, additional measurement capabilities and more frequent
sampling. Scientists on the ground are also measuring cloud properties from
below using ground-based radars.
“A project like IMPACTS can really
complement those spacecraft measurements with aircraft measurements that are
higher resolution, higher accuracy, sample an event more frequently, and
provide additional parameters such as Doppler measurements,” said Yorks.
The other aircraft, the P-3
Orion based out of Wallops, flies at
altitudes up to 26,000 feet. Probes hanging off the P-3’s wings measure the
size, shape and distribution of precipitation particles. Flying the P-3 at
different altitudes allows the team to measure snow particles throughout the
cloud, and the temperature, water vapor, and other conditions in which they
form.
The P-3 also drops small instruments, called
dropsondes, over the ocean. These instruments work like weather balloons in
reverse, measuring temperature, wind and humidity in the atmosphere as they
fall. The team is also launching weather balloons every few hours as the storm
passes overhead from several sites that move depending on which storm the team
is studying. The data collected by the dropsondes and weather balloons provide
information about the atmospheric conditions before, during and after the storm.
“Snowstorms are really complicated storms, and we need every piece of data
– models, aircraft instruments, meteorological soundings – to really figure out
what’s going on within these storms,” said Heymsfield.
The multi-year IMPACTS campaign is the first comprehensive study of
snowstorms across the Eastern United States in 30 years. The science team
includes researchers from NASA, several universities across the country, the
National Center for Atmospheric Research, and NOAA, including partners at the
National Weather Service.
To learn more about the mission, visit: https://espo.nasa.gov/impacts/content/IMPACTS
By Sofie Bates
NASA’s Earth Science News Team
Source: https://www.nasa.gov/feature/esnt/2022/nasa-planes-fly-into-snowstorms-to-study-snowfall
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