Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published August 15, 2008 | Published
Journal Article Open

Short-period solar cycle signals in the ionosphere observed by FORMOSAT-3/COSMIC


We analyze 2 years of the FORMOSAT-3/COSMIC GPS radio occultation data to study the response of the Earth's ionosphere to the solar rotation (27-day) induced solar flux variations. Here we report electron density variations in the ionosphere (∼100–500 km) associated with the 27-day solar cycle. The peak-to-peak variation in electron density at low latitudes in the F2 region is about ∼10^4–10^5 electrons cm^(−3) or 20–40%, and can be as high as 60% depending on altitude, latitude, and season. The half and double periods of the 27-day are also observed at an amplitude comparable to that of the 27-day. The results place useful constraints for modeling chemical and dynamical processes in the ionosphere.

Additional Information

© 2008 The American Geophysical Union. Received 23 April 2008; Revised 30 June 2008; Accepted 11 July 2008; Published 15 August 2008. We thank S. Sander, K. K. Tung, and D. Waliser for valuable inputs. This work was supported in part by an NSC grant 96-2628-M-001-018 to the Academia Sinica. KFL, RLS and YLY were supported in part by NASA MAP program via JPL grant P480501 to the California Institute of Technology. The authors acknowledge the NSPO and UCAR CDAAC groups for providing FORMOSAT-3/COSMIC GPS radio occultation data.

Attached Files

Published - grl24763.pdf


Files (245.5 kB)
Name Size Download all
245.5 kB Preview Download

Additional details

August 22, 2023
October 17, 2023