Jeffrey Forbes

Jeffrey Forbes


Research Focus & Metrics

Academic Career Length

57Years (1970-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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19 December 2002 in Journal of Geophysical Research: Atmospheres
Verified
Journal Article
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MHM. E. Hagan
M. E. Hagan
JFJeffrey Forbes
Jeffrey Forbes

5 February 2003 in Journal of Geophysical Research
Verified
Journal Article
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MHM. E. Hagan
M. E. Hagan
JFJeffrey Forbes
Jeffrey Forbes

1 May 2000 in Journal of Atmospheric and Solar-Terrestrial Physics
Verified
Journal Article
Closed access
JFJeffrey Forbes
Jeffrey Forbes
SPScott E. Palo
Scott E. Palo
XZXiaoli Zhang
Xiaoli Zhang

22 February 2008 in Journal of Geophysical Research
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Journal Article
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JFJeffrey Forbes
Jeffrey Forbes
XZX. Zhang
X. Zhang
SPS. Palo
S. Palo
JRJ. Russell
J. Russell
CMC. J. Mertens
C. J. Mertens
MMM. Mlynczak
M. Mlynczak
The seasonal and interannual variability of migrating (Sun‐synchronous) and nonmigrating solar atmospheric tides at altitudes between 100 and 116 km are investigated using temperature measurements made with the SABER instrument on the TIMED spacecraft during 2002–2006. Quasi‐biennial variations of order ±10–15% in migrating diurnal and semidiurnal tidal amplitudes are found, presumably due to modulation by the quasi‐biennial oscillation (QBO) as the tides propagate from their troposphere and stratospheric sources to the lower thermosphere. A number of nonmigrating tidal components are found that have the potential to produce significant longitudinal variability of the total tidal fields. The most prominent of these, i.e., those that appear at amplitudes of order 5–10 K in a 5‐year mean climatology, include the zonally symmetric (s = 0) diurnal tide (D0); the eastward propagating diurnal and semidiurnal tides with zonal wave numbers s = −2 (DE2 and SE2) and s = −3 (DE3 and SE3); and the following westward propagating waves: diurnal s = 2 (DW2); semidiurnal s = 1 (SW1), s = 3 (SW3), and s = 4 (SW4); and terdiurnal s = 5 (TW5). These waves can be plausibly accounted for by nonlinear interaction between migrating tidal components and stationary planetary waves with s = 1 or s = 2 or by longitudinal variations of tropospheric thermal forcing. Additional waves that occur during some years or undergo phase cancellation within construction of a 5‐year climatology include DW5, SE1, SE4, SW6, TE1, TW1, and TW7. It is anticipated that the winds that accompany all of these waves in the 100–170 km region will impose longitudinal variability in the electric fields produced through the ionospheric dynamo mechanism, thereby modulating vertical motion of the equatorial ionosphere and the concomitant plasma densities. In addition to the wave‐4 modulation of the equatorial ionosphere that has recently been discovered and replicated in modeling studies, the waves revealed here will generate wave‐1 (SW1, SW3, D0, DW2), wave‐2 (SW4, TW1), wave‐3 (DE2, SE1), wave‐4 (DE3, SE2, DW5, SW6, TE1, TW7), wave‐5 (SE3), and wave‐6 (SE4) components of this ionospheric variability, depending on year and time of year. However, the absolute and relative efficiencies with which these waves produce electric fields remains to be determined.

1 August 1981 in Reviews of Geophysics
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Journal Article
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JFJeffrey Forbes
Jeffrey Forbes

15 April 1995 in Geophysical Research Letters
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Journal Article
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MHM. E. Hagan
M. E. Hagan
JFJeffrey Forbes
Jeffrey Forbes
FVF. Vial
F. Vial