Skip to data content Skip to data search

CEPEX ER-2 Lyman Alpha (Water Vapor)


This dataset contains water vapor measurements from the Harvard University Lyman Alpha instrument aboard the ER-2 for 9 missions during CEPEX. The instrument used the techniques of photofragment fluorescence combined with dual path absorption to measure water vapor concentrations ranging from 1013 to 1016 molecules/cubic centimeters at pressures from 50 to 500 mb. The detection scheme utilized the Lyman-Alpha photons (121.6 nanometers) to photo- dissociate water vapor and produce excited OH molecules which emit photons that are detected by a photomultiplier near 314 nanometers. Units are in ppmv. Principal Investigators were Weinstock, Dessler, Hintsa, and Anderson (Harvard University).

Data access

  • ORDER data for delivery by FTP

Additional information

Metadata download

Note that your browser may not display the above metadata links, but automatically save them as files in a folder such as "Downloads"

Related projects
Spatial Type point
Frequency 1 second
Language English

Temporal coverage

Begin datetime 1993-03-17 00:00:00
End datetime 1993-04-05 23:59:59

Spatial coverage

Map data from IBCSO, IBCAO, and Global Topography.

Maximum (North) Latitude: 20.00, Minimum (South) Latitude: -20.00
Minimum (West) Longitude: -140.00, Maximum (East) Longitude: 140.00

Primary point of contact information

EOL Data Support <>

Additional contact information


Example citation following ESIP guidelines:

Weinstock, E. 2006. CEPEX ER-2 Lyman Alpha. Version 1.0. UCAR/NCAR - Earth Observing Laboratory. Accessed 12 Nov 2019.

Today's date is shown: please replace with the date of your most recent access.

This dataset does not have a DOI. If you plan to cite this dataset, please email us to request a DOI, which will improve the searchability and cross-referencing of the citation.