National Aeronautics and Space Administration

NASA Ames Research Center, Silicon Valley, CA 94035-1000

650-604-9000

FS-2000-1-01-ARC

David Steitz

NASA Headquarters, Washington, DC

(Phone: 202/358-1730)

Chris Rink

NASA newsroom, Kiruna, Sweden (1/21 through 1/28/2000)

(Phone: 46-980-398-787) E-mail: c.p.rink@express.larc.nasa.gov

John Bluck

NASA Ames Research Center, Silicon Valley, CA

(Phone: 650/604-5026 or 604-9000) E-mail: jbluck@mail.arc.nasa.gov

Scientists recently made more measurements than ever before
of polar stratospheric clouds (PSCs) that trigger ozone loss in the
stratosphere. The research was part of the largest ozone field experiment
to date that began in November 1999 to assess the state of the
stratospheric ozone layer over the Arctic. More than 350 researchers are
taking part in the field campaign that is slated to continue until March
2000.

The Earth’s stratospheric ozone layer protects life below from harmful
ultraviolet radiation coming from the Sun that can lead to the formation of
skin cancers. The stratosphere is the region of the atmosphere that is
from about 30,000 ft. to 180,000 ft. above the Earth’s surface.

The ozone molecule consists of three atoms of oxygen,
whereas the most common oxygen molecule exists as two joined atoms of
oxygen. Ultraviolet sunlight shining on oxygen molecules in the upper
atmosphere creates ozone gas.

NASA Facts –page 2 — First Phase of the SOLVE Field Campaign (Arctic
Ozone/atmospheric experiment)

More than a decade ago, researchers from around the world recognized that
man-made chlorine and bromine compounds primarily cause ozone depletion.
PSCs provide the surfaces on which a series of chemical reactions take
place that release destructive forms of chlorine and bromine.

Scientists have observed unusually low levels of ozone over the
Arctic during recent winters, raising concerns that ozone depletion there
could become more widespread as in the Antarctic ozone hole. Scientists
also hope to forecast when the Arctic ozone may return to normal.

The field experiment is based north of the Arctic Circle in Kiruna Sweden.
“Arena Arctica,” a large hangar built especially for research, houses the
instrumented aircraft as well as scientists.

Researchers are measuring ozone and other atmospheric gases during
the Arctic winter using instruments on the ground and aboard satellites,
airplanes, and heavy-lift and small balloons. The three periods of the
field campaign include: December 1999, now complete; January 2000, when
there is the greatest possibility of polar stratospheric clouds (PSCs); and
March 2000, when maximum ozone loss is likely.

European airplanes will join NASA’s DC-8 and ER-2 research aircraft during
the January/February deployment period of the campaign. Researchers are
launching balloons from Esrange, a balloon and rocket launch facility near
Kiruna.

The Arctic was very cold when the 1999-2000 winter began,
creating favorable conditions for the formation PSCs. These clouds begin
the complex process of ozone breakdown. Although the stratosphere is very
dry, extremely cold temperatures cause clouds to form. These polar
stratospheric clouds (PSCs) enable very interesting chemical reactions
(known as
heterogeneous chemical processes) that accelerate ozone loss.

NASA’s DC-8 arrived in Kiruna on Nov. 29, 1999, and returned to
the United States on Dec. 16, 1999. By then, researchers had taken more
measurements of PSCs than ever before.

The main objectives of the first stage of the campaign were to measure the
distribution of ozone before the expected late-winter ozone loss and to
hunt for PSCs in early winter.

To help find PSCs, weather forecasters first determined the location of the
polar vortex and the areas where temperatures were expected to be low
enough to begin producing PSCs. The polar vortex is the wintertime weather
pattern in which the stratosphere flows counterclockwise around the North
Pole.

NASA Facts –page 3 — First Phase of the SOLVE Field Campaign (Arctic
Ozone/atmospheric experiment)

The DC-8 aircraft flew to those regions where onboard Light Detection and
Ranging (LIDAR) instruments could probe the PSC clouds. LIDAR is similar
to radar, but uses lasers to enable researchers to obtain atmospheric data.
Scientists found that PSCs were almost always over very high latitude
islands – and unexpected discovery.

During the first flights of the DC-8 aircraft, scientists also found colder
than expected temperatures inside the vortex northeast of Kiruna over Franz
Josef Land, Russia. This proved to be an area of particularly good PSC
hunting on later flights.

The four science flights over Russian territory were historic firsts for
the DC-8 and were closely coordinated with Russian scientists and members
the SAGE III Ozone Loss and Validation Experiment (SOLVE) operational team.
During these DC-8 research flights, scientists extensively sampled PSCs as
the aircraft flew through an expanding “cool pool” of air in the vortex.
The airborne researchers also measured the mountain waves that appear to
contribute to PSC formation. Mountain waves are waves in the atmosphere
caused by wind flowing over mountain ranges.

Two other DC-8 flights outside of Russian airspace were dedicated to
obtaining important correlative measurements intended to help improve
space-based observations of atmospheric ozone and aerosols. Two
NASA-sponsored SOLVE balloons successfully flew into the polar vortex. The
first balloon and its onboard instruments rose to more than 100,000 ft.
Nov. 19. A second remote-sensing balloon flew to an altitude of 108,000
ft. Dec. 3. Both balloons landed safely in Finland.

The polar vortex had moved overhead, according to researchers. Both
balloons measured very old air that had moved down from a higher altitude,
100,000 ft. to 12,000 ft. This air mass contained ozone, synthetic
compounds called chlorofluorocarbons (CFCs) and other related climate
gases. Scientists said they found old air with gases and trace elements
from 1994 in the atmosphere. Researchers defined old air as older air
gases estimated from chemical traces taken in the early to mid 1990’s based
on CFC measurements done at the same time.

SOLVE is being conducted jointly with the European Commission-sponsored
third European Stratospheric Experiment on Ozone (THESEO) 2000. Research
teams include scientists from NASA, Europe, Russia, Japan and Canada who
are cooperating to obtain data in the effort to better understand ozone
loss, which is of great concern to many countries.

NASA Facts –page 4 — First Phase of the SOLVE Field Campaign (Arctic
Ozone/atmospheric experiment)

More information (including a list of participating institutions) can be
found at:
(SOLVE) — http://cloud1.arc.nasa.gov/solve/index.html

(THESEO 2000) — http://www.ozone-sec.ch.cam.ac.uk

http://george.arc.nasa.gov/dx/basket/factsheets/FS991103.html

http://hyperion.gsfc.nasa.gov/Personnel/people/Newman,_Paul_A./solve_write.html

Some images taken by SOLVE mission members are on the Internet at:

ftp://code916.gsfc.nasa.gov/pub/solve/images/

http://cloud1.arc.nasa.gov/solve/pao

NASA will establish a newsroom in the Scandic Hotel Ferrum in Kiruna during
“media week,” Jan. 21 – 28, 2000. Journalists may be escorted into the
research area to meet with operational and scientific personnel. There are
daily commercial airline flights from Stockholm to Kiruna.