Timed:CCD Spectrophotometers

From CedarWiki
Jump to: navigation, search

GBI CCD Spectrophotometers for TIMED

The basic geophysical output of CCD Spectrophotometers (CCDSs) is the neutral temperature at the peak of the [OH] and [O2(0,1)] peaks, which are about 87 km and 93 km. Clouds are not a big problem for temperature measurements, so there are temperature values approximately every 2-10 minutes for most of the periods of darkness. This is only true if there are no aurora. If there are aurora, then the [OH] airglow emission is swamped by auroral emissions, and then the temperature, and sometimes the density ratios of other chemical species can be found.

G. G. Sivjee (sivjee@db.erau.edu) of Embry-Riddle Aeronautical University is responsible for the analysis of 5 CCD Spectrophotometers (or Spectrographs) and one Ebert-Fastie Spectrophotometer (EFS). The Eber-Fastie is similar to the CCDS(?). A sixth CCDS at Daytona Beach will donate data to TIMED (*).

The CCDSs use a spectrum between about 700-960 nm where there are several hydroxyl Meinel (OH-M) bands that emit around 87 km, and the molecular oxygen atmospheric (O2 At) bands such as O2 (0,1) that emit around 93 km in airglow. Atomic oxygen OI lines are also seen in airglow, where the peak emission is about 97 km. When aurora are present, the airglow emissions can be swamped by the auroral emissions from O2 At bands, N2 1PG bands, N2+ Meinel bands, N lines, and OI and OII lines at higher altitudes. The temperatures and line or band brightnesses are found, which give information on the temperature, density, and wave activity of the emitting region. For airglow, temperature and brightness will be provided for the OH-M (6,2) band and the O2 At(0,1) band. For aurora, brightness from the OI 777.4 and 844.6 nm lines will be given, as well as band brightness and temperatures from the N2 1PG (1,0), N2+ M (1,0) and O2 At (1,1) bands. See Eureka for a complete description of the instruments.

Richard Walterscheid and Doug Strickland are co-PIs with Abas Sivjee on the CEDAR/TIMED grant.

Site Lat Lon Type Kinst Contact
South Pole, Antarctica -90.00 0.00 CCDS 3000 G. G. Sivjee
South Pole, Antarctica -90.00 0.00 EFS 3001 G. G. Sivjee
Adelaide, Australia -34.93 138.60 CCDS 3040 G. G. Sivjee
Daytona Beach, FL, USA 29.199 -81.05 CCDS* 3090 G. G. Sivjee
Sondrestrom, Greenland 66.99 -50.95 CCDS 3420 G. G. Sivjee
Longyearbyen, Svalbard NO 78.15 16.05 CCDS 3500 G. G. Sivjee

Eureka, Canada

80.22 -86.18 CCDS 3520 G. G. Sivjee

--Revised 05 Oct 2004 by emery@ucar.edu