The Halogen Occultation Experiment

The HALOE instrument flies on the Upper Atmosphere Research Satellite (UARS), and has been in operation since October 1991. It views solar infrared radiation by means of solar occultation, and measures water vapour, ozone, methane, hydrogen fluoride (HF), hydrogen chloride (HCl), nitrogen oxode (NO), nitrogen dioxide (NO₂), temperature and aerosols. Latitudinal coverage is from 80^oS to 80^oN over the course of a year, and the altitude range of the measurements extends from 15 km to 60-130 km (depending on the constituent observed). Advantages of HALOE include high accuracy and self-calibration. In addition, HALOE is still in operation (at time of writing) and thus is very useful in the study of interannual variability of middle atmospheric constituents. Accordingly, the HALOE dataset forms a highly important basis of much middle atmosphere research.

Further information on HALOE is available from the HALOE homepage. The data is available from the
BADC (UK) or the UARS central data handling facility , which also contains links to the homepages of other UARS instruments.

HALOE Research at Imperial College

A Users Guide is available to help new users locate, read and analyse the HALOE data available at Imperial College (Internal Users only).

John Harries heads the research effort at Imperial College. He is a member of the HALOE Science Team and played an important role in the development of the HALOE instrument. Recent HALOE papers include:
 

*    Study of the Antarctic stratosphere in springtime, including evidence of drying in the Antarctic stratosphere

        (abstract ) and absorbing layers (abstract ).

*    Validation of the HALOE water vapour retrievals ( abstract ).

*    The distribution of mesospheric molecular hydrogen inferred from HALOE H₂O and CH₄ measurements

        (abstract ).

Dr. R. Toumi is interested in recent observations of water vapour trends as seen by HALOE.  It seems the stratopshere is getting wetter! (abstract)


Adam Hicks is examining HALOE nitric oxide and ozone measurements in the lower stratosphere, to identify important dynamical and chemical processes operating in this region of the atmosphere.

A  Reference List  of past work done by the group associated with HALOE is available.

Back to SPAT home page.