Summary: GRAVITY WAVE DYNAMICS AND EFFECTS IN THE MIDDLE
David C. Fritts and M. Joan Alexander
Colorado Research Associates Division
Northwest Research Associates
Boulder, Colorado, USA
Received 6 July 2001; revised 29 August 2002; accepted 6 November 2002; published 16 April 2003.
 Atmospheric gravity waves have been a subject of
intense research activity in recent years because of their
myriad effects and their major contributions to atmo-
spheric circulation, structure, and variability. Apart from
occasionally strong lower-atmospheric effects, the major
wave influences occur in the middle atmosphere, be-
tween 10 and 110 km altitudes because of decreasing
density and increasing wave amplitudes with altitude.
Theoretical, numerical, and observational studies have
advanced our understanding of gravity waves on many
fronts since the review by Fritts [1984a]; the present
review will focus on these more recent contributions.
Progress includes a better appreciation of gravity wave