Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ), a joint venture between NOAA and NASA, is a comprehensive wildfire smoke investigation and the latest in a long history of collaborative research between the two federal science agencies.
Mission planning for FIREX-AQ is complex: hundreds of instruments and scientists from six federal agencies, 22 academic institutions, two foreign governments, and numerous private-sector companies will collaborate in a complex logistical operation that launches in late May.
A major task is the five-week process of installing scientific instruments in the NASA DC-8 flying laboratory in Palmdale, CA.
Starting June 24, three days of flights for NASA's Student Airborne Research Program will give rising senior undergraduate students hands-on experience in all aspects of an airborne research campaign on the DC-8.
Several days of final preparation in mid-July precede a July 22 arrival at the Idaho Air National Guard base at Gowen Field in Boise, which is the base for studies of wildfire smoke.
Two smaller research aircraft, NOAA Twin Otters, will join the DC-8 in Boise in late July. These aircraft will investigate fire weather conditions and nighttime smoke chemistry at the regional and local scale in the northwest U.S.
The NASA ER-2 high-altitude research aircraft will carry satellite simulator instruments in its belly. The ER-2 will reach ~70,000 feet altitude, and will fly from its base in California in a suburb of Los Angeles, to coordinate with the DC-8.
Ground based operations in Idaho and across the northwest U.S., including mobile laboratories (instrumented vehicles), will provide continuous, surface based measurements to complement the periodic airborne data from the DC-8 and the Twin Otters. The mobile laboratories will be able to measure the smoke where it matters most to health - at lower altitudes than can't be easily sampled with aircraft. Ground-based remote sensing instruments will help make connections to climate and optics.
On August 19, the NASA DC-8 flies to Salina, KS to focus on smoke from agricultural fires across the southeastern U.S. that concludes September 5. Large western fires could still be sampled during this period if deemed appropriate by the science team.
The final phase of the mission will focus on smoke from a U.S. Forest Service prescribed burn planned for October or November. This rare opportunity is particularly exciting for scientists because the burn area will be carefully mapped to describe fuel types and amounts before and after the burn. This will permit monitoring of smoke with the DC-8 as well with many other instruments deployed by the Forest Service and other partners from carefully mapped fuels in a realistic wildfire.
A primary objective of FIREX-AQ is to combine near and far-field observations to understand emissions, chemical evolution, transport and evaluate downwind impacts of wildfires in coordination with interagency partners. The airborne component of the FIREX-AQ effort, centered on the deployment of the NASA DC-8 with two complementary instrumented NOAA Twin Otters, will sample wildfire plumes from near the point of emission to downwind on a regional scale. These efforts will provide data to understand the influence of fire emissions on the atmospheric composition continuously from the fire location to impacts far from the source. Wildfire plumes frequently affect many people directly by exposing population centers with large concentrations of pollutants, both close to the fires and sometimes far downwind. Fire plumes affecting populated areas will be given priority in designing flight plans for sampling.
Partners from the Joint Fire Science Program (JFSP) will use their knowledge of ground conditions for fuel and fire characterization to advise on the best targets for airborne fire-plume sampling. The NASA DC-8 has the ability to explore an extremely wide range of smoke age and will coordinate with the NOAA Twin Otter instrumented aircraft that are focused on narrower ranges of smoke age with complementary payloads. For example, a Twin Otter will sample individual fires throughout the day to understand the diurnal changes of fire emissions and fire plumes at night to investigate the nighttime chemical evolution of fire plumes. Further, Twin Otters will generally be able to obtain higher spatial resolution measurements and undertake more focused studies of rapidly evolving chemical evolution over shorter spatial scales than the DC-8 instruments.
A second primary objective for FIREX-AQ is to exploit the range and endurance of the NASA DC-8 to sample a large number of small, mostly prescribed fires used to manage mostly agricultural lands, to build statistics on emission factors and fuels, plume rise, satellite detectability, and integrated impacts for these types of sources.
Confidence that the DC-8 can adequately accomplish this objective comes from its demonstrated performance in sampling fifteen small agricultural fires during the 2013 SEAC4RS Airborne Science Campaign. Given the modest amount of flight time dedicated to small fire sampling during SEAC4RS, it is expected that many more fires can be sampled during FIREX-AQ. This objective provides the best opportunity to build on the needed statistics for emission factors and plume rise as they relate to fuel type, fire intensity, and temperature and complements emission factor work at the 2016 Fire Lab study conducted by NOAA in advance of FIREX-AQ.
Extensive coordination with state and local authorities will be needed to anticipate when and where to expect burning, as well as to obtain ground-level data to the extent possible for understanding the fuel and conditions under which burning occurred. The information gathered from small fires will also provide an opportunity to assess current satellite detection capabilities and reduce uncertainty in the contribution of small fires to total emissions.
The third main sampling goal for FIREX-AQ is coordination with the Fire and Smoke Model Evaluation Experiment (FASMEE), which could offer the opportunity to sample one or more large prescribed fires planned and executed by JFSP partners in October or November. This planned and controlled burn is of special interest because maximum information will be available on the variables affecting fire behavior, development, dynamics, and emissions from the JFSP partners. Along with the information gathered before, during, and after the fire, airborne observations gathered during FASMEE provide the best chance for bridging laboratory and ambient fires. Fuels from potential FASMEE burn sites were burned during the pre-campaign Fire Lab experiment at Missoula in 2016.