The Airborne Arctic Stratospheric Expedition (AASE)

In January and February of 1989, the NASA ER-2 and the DC-8 aircraft were flown out of Stavanger, Norway, to investigate whether the same kinds of chemistry which create the Antarctic ozone hole were also occurring in the Northern Hemisphere Arctic regions. This was the AASE mission.

AASE began about a year and a half after the Airborne Antarctic Ozone Experiment (AAOE), which determined that the ozone hole which appears each year over Antarctica was caused by perturbed chlorine chemistry. Stratospheric conditions in the Southern Hemisphere winter are different in some important respects from those of the Northern Hemisphere: the southern temperatures are colder (and the cold temperatures last longer), and the ring of winds which circles the pole--the polar vortex--is more circular and isolates the polar air more. These differences should have a strong effect on relevant chemical reactions taking place. Therefore, it was important to take measurements in the Northern polar winter to see whether the same kinds of processes were occurring there as in the Southern Hemisphere.

---

Some sights from the mission

Here are some pictures taken during the AASE mission.

---

The Official NASA web page for the AASE experiment is maintained by the Earth Science Division Project Office at NASA Ames Research Center.

---

AASE Investigators

• Project Leadership
  • A. Tuck (NOAA Aeronomy Lab): Project Scientist
  • B. Toon (NASA Ames): DC-8 Flight Scientist
  • S. Wegener (NASA Ames): ER-2 Science Coordinator, Instrument Manager, & Project Control Officer
• ER-2 instruments
  • J. Anderson (Harvard): Multiple axis resonance fluorescence chemical conversion detector for ClO and BrO
  • K.R. Chan (NASA Ames): ER-2 meteorological measurement system
  • D. Fahey (NOAA Aeronomy Lab): NO and NOy detector
  • G. Ferry (NASA Ames), B. Gandrud (NCAR), and J. C. Wilson (U. Denver): Aerosol and cloud spectrometers
  • B. Gandrud (NCAR): Multi filter sampler
  • B. Gary (NASA Ames): Microwave temperature profiler
  • L. Heidt (NCAR) & J. Vedder NASA Ames): Whole air sampler
  • K. Kelly (NOAA Aeronomy Lab): Lyman alpha hygrometer
  • M. Lowenstein (NASA Ames): Airborne tunable laser absorption spectrometer
  • M. Proffitt (NOAA Aeronomy Lab): Dual-beam UV-absorption ozone photometer
  • R. Pueschel (NASA Ames): Particle chemistry impactor experiment
  • J. C. Wilson (U. Denver): Condensation nucleus counter
• DC-8 instruments
  • E. Browell (NASA Langley): ozone and aerosol DIAL system
  • M. A. Carroll (NOAA Aeronomy Lab): Chemiluminescent No detector/photolytic converter
  • C. Farmer (NASA JPL): Mark IV interferometer
  • G. Gregory (NASA Langley): Chemiluminescent ozone detector
  • L. Heidt (NCAR) & J. Vedder (NASA Ames): Whole air sampler
  • G. Hubler (NOAA Aeronomy Lab): DC-8 reactive odd nitrogen (NOy) detector
  • K. Kelly (NOAA Aeronomy Lab): Lyman alpha hygrometer
  • B. Mankin and M. Coffey (NCAR): Fourier transform spectrometer
  • M. McCormick and L. Poole (NASA Langley): Langley dual-polarization aerosol lidar
  • A. Wahner (KFA Julich): KFA Near UV atmospheric absorption experiment
• Theory team
  • R. Jones (UK Met Office): homogeneous and heteogeneous chemistry along air parcel trajectories
  • M. McElroy and S. Wofsy (Harvard): Ice-chemistry models
  • M. McIntyre (Cambridge): Analytic and computer models of arctic vortex, high-res transport
  • M. Schoeberl (NASA Goddard): Real time vorticity computations and conservative coordinate mapping.
  • R. Stolarski (NASA Goddard): 3D assimilation and transport

What this mission accomplished

AASE found that the chlorine chemistry in the Northern Hemisphere polar winter stratosphere was indeed perturbed, similar to the situation in the Southern Hemisphere winter. Large amounts of chlorine monoxide were found in the polar regions.

The AASE results were published in a special issue of Geophysical Research Letters, vol. 17, no. 4.