Solar activity variations in midlatitude thermospheric meridional winds

Journal Article · Thu Sep 01 04:00:00 EDT 1994 · Journal of Geophysical Research

DOI:https://doi.org/10.1029/94JA01134· OSTI ID:166281

Hedin, A E ^[1]; Buonsanto, M J ^[2]; Codrescu, M ^[3]

---

1. NASA Goddard Space Flight Center, Greenbelt, MD (United States)
2. Massachusetts Institute of Technology, Westford, MA (United States)
3. NOAA, Boulder, CO (United States); and others

Upper thermospheric meridional wind data at midlatitudes and for low magnetic activity are examined for solar activity variations following an analysis scheme suggested by a Coordinated Analysis of the Thermosphere workshop. Wind data from incoherent scatter, Fabry-Perot, and F2 peak heights show decreasing diurnal amplitudes with increasing solar activity during all seasons, except for Saint Santin data, which show a slight increase in summer. Equivalent winds from F2 peak height data have strong decreases in diurnal amplitude in all seasons. The coupled thermosphere ionosphere model and thermosphere ionosphere global circulation model predictions of diurnal amplitude, while differing considerable in magnitude, also show decreasing amplitudes during all seasons. The diurnal mean wind trends with solar activity are fairly weak, except for Millstone Hill incoherent scatter radar, which shows a shift from strong southward to near zero or northward wind with increasing activity. Model results for the mean generally fall within the band of measurements. Near midnight, most of the data also show that typically southward winds weaken with increasing solar activity in all seasons except summer, when results are mixed. There are significant differences between the trends and between absolute values for the various data sets and models which need further investigation. 26 refs., 4 figs., 2 tabs.

• OSTI ID: 166281
• Journal Information: Journal of Geophysical Research, Journal Name: Journal of Geophysical Research Journal Issue: A9 Vol. 99; ISSN JGREA2; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
CORRELATIONS
DAILY VARIATIONS
LATITUDE EFFECT
SOLAR ACTIVITY
THERMOSPHERE
WIND