Q. What is ARCTAS?
Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) is an extensive NASA airborne field campaign to investigate the chemistry of the Arctic's lower atmosphere. Flights for the summer deployment begin the week of June 29 from Cold Lake, Alberta, Canada, and will examine the contribution of forest fires to Arctic pollution. ARCTAS is the largest airborne experiment ever undertaken to study the impact of air pollution on arctic climate.
Q. What are boreal forests and why study fires in these forests?
Boreal forests, spanning much of Earth's northern latitudes, have faced the heat over the last decade amid increases in natural forest fires. In particular, researchers have debated the degree to which these fires contribute to the Arctic's atmosphere compared to human-caused sources at lower latitudes. Researchers want to better define the contribution of these sources to arctic pollution and the impact on climate.
Q. How many NASA aircraft are contributing to ARCTAS?
Three aircraft with more than 30 instruments will fly during ARCTAS. The P-3B from Wallops Flight Facility, Wallops, Va., carries nine instruments up to 20,000 feet, and the DC-8 from Dryden Flight Research Center, Edwards, Calif., carries 22 instruments up to 40,000 feet. These two aircraft will be making flights for ARCTAS from Cold Lake, Alberta, Canada. The B-200 from Langley Research Center, Hampton, Va., flies with two instruments to 25,000 feet, and will support ARCTAS from Yellowknife, Northwest Territories, Canada.
Q. How many scientists and support staff are involved in ARCTAS?
A. Roughly 120 scientists and support staff will support ARCTAS from Cold Lake, and about 25 people from Yellowknife. For a full list of ARCTAS participants, visit http://www.espo.nasa.gov/arctas/participants
Q. Why is the campaign based in Cold Lake, Canada?
Cold Lake offers the best facilities at a high latitude location allowing almost all flight hours to be scientifically useful for studying smoke plumes from boreal forest fires. Flying from a lower latitude location would use up hours of flight time in trying to reach distant targets of scientific interest.
Q. What types of data are being collected?
The series of flights will carry an array of specialized instruments to collect comprehensive measurements of the lower atmosphere, including gases, aerosols and detailed solar radiation measurements, with a focus on smoke emissions from forest fires. Previous campaigns have focused on the lower atmosphere to better understand the impact of natural and artificial sources of pollution on ozone, aerosols and climate. ARCTAS will extend these measurements aided by current technology to make more complete measurements integrated with satellite measurements that have not been available before.
Yellowknife will host a portable science station from Pennsylvania State University that collects ground-based ozone and aerosol measurements, in conjunction with daily launches of balloon-borne instruments planned by partners at Environment Canada and the National Oceanic and Atmospheric Administration.
Q. What NASA satellites are contributing to ARCTAS?
A number of Earth-observing satellites that pass over the Arctic will have the opportunity to contribute to ARCTAS. They include NASA's Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO), which can help researchers determine the vertical location of smoke plumes and aerosols from fires -- information that is critical for diagnosing plume transport downwind. Complimenting those data, the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument measures the horizontal extent of smoke plumes. The chemistry of fire plumes will be examined by instruments on the Aura satellite.
Q. Are ARCTAS flights being planned to coincide with these satellite overpasses?
Yes. Every flight will be planned to fly in coordination with satellites. Given that polar-orbiting satellites have a high density of observations at high latitudes, scientists hope to coordinate with multiple satellite overpasses in a single flight. While direct coordination is usually focused on a particular satellite instrument, the data will be of use to many satellites as several of them make observations over a common region within a very short time window. Many of these satellites are part of NASA's "A-Train" constellation, five satellites flying in close formation orbiting the Earth once almost every 100 minutes. Successful coordination of these satellite overpasses of the Arctic with aircraft flights will rely on good weather and the ability of the aircraft to be in the right place at the right time. Some satellite observations, such as those from CALIPSO, are localized to the area directly beneath the satellite. While geographically limited, these observations offer better information on the vertical distribution of atmospheric constituents. Other satellites, such as the Ozone Monitoring Instrument on the Aura satellite, provide a much broader geographical perspective, looking side-to-side over a swath hundreds of miles wide but with very low vertical resolution.
Q. Will there be international collaboration?
The ARCTAS mission will include Canadian scientific participation, with Canadian researchers being supported by NASA and Environment Canada. There is a possibility that NASA aircraft will stopover at Thule Air Base, Greenland, given that the proper atmospheric conditions and science priorities materialize during the mission.
ARCTAS flights will be coordinated with research flights from Kangerlussuaq, Greenland being conducted by the Centre National de la Recherche Scientifique -- a French government-funded research organization -- and the German Aerospace Center.
The impetus for ARCTAS is partially due to the large international cooperation due to the International Polar Year: http://www.nasa.gov/mission_pages/IPY/main/index.html
Q. How does the summer deployment differ from the spring deployment of ARCTAS?
While the science instruments on the aircraft will remain the same, areas targeted to study differ between the two deployments. The spring deployment sought to uncover the composition and transport pathway of pollution contributing to springtime "arctic haze," while the summer deployment will seek out composition and evolution of smoke plumes from forest fires. Together, the data will help researchers improve the usefulness of satellite measurements and models to better understand the nature of human and natural impacts on the Arctic's atmosphere.
Q. What is ARCTAS-CA?
Prior to the ARCTAS deployment in Canada, NASA will conduct a series of flights with scientists from the California Air Resources Board. The flights, already configured for the ARCTAS mission, will examine California's atmosphere to better understand the chemical dynamics of smog and greenhouse gases over the state.