"The HIRDLS Experiment: Fighting Back from a Murphy's Law Hit"

Seminar by

Dr. John Gille,
National Center for Atmospheric Research, Boulder and the University of Colorado, Boulder

Abstract: The High Resolution Dynamics Limb Sounder (HIRDLS) instrument was designed to provide data from the upper troposphere (~ 8 km) to the mesopause (~ 80 km) with higher vertical and horizontal resolution than previously available. Following its launch on the Aura spacecraft in July 2004 the signals were much larger and more uniform than expected. Subsequent investigation suggested that a piece of plastic film lining of the foreoptics cavity came loose and lodged in a location where it blocked most of the aperture, leaving no completely clear view to space and the atmosphere.

After discussing this, the talk will go on to describe some of the difficulties this created, and how the HIRDLS team has been able to overcome many of them. Results will be presented to illustrate the present level of corrections. Prospects for future improvements will be briefly noted.

BIOGRAPHY: John Gille received his B.S. in Physics from Yale, an M.A. in Physics from Cambridge University, and Ph.D. in Geophysics from MIT (for research done at Harvard). He taught Meterorology at Florida State University before coming to NCAR. He served as P.I. on the Limb Radiance Inversion Radiometer (LRIR) and Limb Infrared Monitor of the Stratosphere (LIMS) on Nimbus 6 and 7. He was a collaborative investigator on the CLAES instrument on UARS, and is presently U.S. P.I. on the Measurements of Pollution
in the Troposphere (MOPITT) and the High Resolution Dynamics Limb Sounder (HIRDLS) on the EOS Terra and Aura satellites,respectively. Since 1997 he has had a half time appointment at the University of Colorado.