Extra long period (20-40 day) oscillations in the mesospheric and lower thermospheric winds: observations in Canada, Europe and Japan, and considerations of possible solar influences

Details Extra long period (20-40 day) oscillations in the mesospheric and lower thermospheric winds: observations in Canada, Europe and Japan, and considerations of possible solar influences Extra long period (20-40 day) oscillations in the mesospheric and lower thermospheric winds: observations in Canada, Europe and Japan, and considerations of possible solar influences

Jan 2001

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2001jastp..63..835l&link_type=abstract

Journal of Atmospheric and Solar-Terrestrial Physics, Volume 63, Issue 9, p. 835-852.

Physics

22

Scientific paper

An extra long period (20-40 day) oscillation has been identified in the mesospheric and lower thermospheric (60-100 km) winds observed simultaneously by radars (MF, LF) at four sites from /70°N to /30°N in the northern hemisphere during the winter of 1995//1996. A long-term (1980-1999) investigation of this oscillation at Saskatoon and Collm is also carried out to obtain climatological and statistical characteristics. Spectral analysis has shown that this oscillation is a common feature of the winter (November-March) atmosphere, having strong amplitudes throughout the mesosphere (~10m/s) and lower thermosphere (~5m/s), and being much stronger at mid-low latitudes. Although the oscillation has a climatology similar to the long period normal mode planetary waves (10-16 day), the phases at the various sites are very similar, and not consistent with a freely propagating wave. Comparisons with geomagnetic//solar wind parameters and solar UV radiation suggest that the oscillation could be related to the short-term solar rotation period (ca. 27 days) in some way. However the range of observed wind periods is very broad and this raises questions about this interpretation. Nevertheless the inter-annual variations of this 20-40 day oscillation indicate a weak 11-year solar cycle correlation in the mesosphere (positive) and the lower thermosphere (negative). Also, the cross-correlation between the winds and solar radiation shows significant quasi 27-day correlation and the wind lags behind the solar radiation a few days in the mesosphere. In general it is implied that the atmosphere could react to the solar activity in an indirect way due to certain dynamical mechanisms.

Affiliated with

Also associated with

No associations

Rating

Extra long period (20-40 day) oscillations in the mesospheric and lower thermospheric winds: observations in Canada, Europe and Japan, and considerations of possible solar influences does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Extra long period (20-40 day) oscillations in the mesospheric and lower thermospheric winds: observations in Canada, Europe and Japan, and considerations of possible solar influences, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Extra long period (20-40 day) oscillations in the mesospheric and lower thermospheric winds: observations in Canada, Europe and Japan, and considerations of possible solar influences will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1363500