evolving nature of satellite studies

1. evolving nature of satellite studies

2. diurnal cycle for a detailed look, need more than one satellite in different orbits • sun synchronous: 2 local times, slightly better with multiple viewing directions • precessing: normally takes weeks or months to cover all local times questions • tidal forcing (much of it comes from ozone heating in the stratosphere) • how does the forcing vary with longitude? • how does the tide itself respond to forcing variations? • is there a dependence on the QBO? through ozone, winds, etc.? • diurnal chemistry • behavior around sunrise/sunset

3. QBO in MLT tide & wind • stratospheric winds filter waves • ozone varies with QBO • mean wind varies with QBO MSAO QBO HRDI figures made by Mark Burrage

4. QBO of diurnal tide - SABER T 2002-2005 magnitude of QBO in tide amplitude comparable to semiannual (SAO) and annual (AO) variations 2.2 13 4 year average QBO 2.2 3.2 SAO AO from Xu et al., paper in preparation, 2007

5. no apparent QBO in diurnal tide phase QBO in amplitude: equinoctal maximum larger when stratospheric QBO is westerly stratospheric wind 30 hPa from Xu et al., paper in preparation, 2007

6. tides in the stratosphere cosine component of migrating diurnal tide T, calculated using Salby method from sun synchronous (LIMS) tide definitions migrating • westward following the sun • forcing • solar heating • daily patterns of latent heat non-migrating • everything else • forcing • solar heating • wave-wave interaction • latent heat from Lieberman, JAS 1991

7. stratospheric role in tidal variability NH 12-hr tidal amplitude (wind at 81 km; radar data) SH planetary wave (6 hPa, 50-5S; SABER data) • apparent relationship between tide at summer mesopause and waves in winter stratosphere Smith et al., GRL, 2007

8. stratospheric PW1 and tidal variability correlation in time of NH 12-hr tidal amplitude (wind at 81 km from radar data) with stratospheric PW1 amplitude (from SABER) unshaded = significant 5 months of each year, daily data x • correlation persist over four years • possible reasons • wave-wave interaction • tide responding to mean wind variations • perturbation in forcing due to O3 variations BTW, you must have precession or multiple satellites to determine 12-hour variations Smith et al., GRL, 2007

9. interaction of transport, heating, dynamics in the tropics • wave forcing of SAO & QBO • role of ozone transport & heating in these oscillations • interaction between SAO & QBO • interactions between high & low latitudes • physical/chemical mechanisms that would cause interaction between the QBO and solar cycle

10. ozone-QBO interaction numerical model results • interactive ozone slows down QBO period, changes structure ozone interactive ozone not interactive from Shibata & Deushi, GRL, 2005

11. inertial instability - seen in CRISTA perturbation TNovember 1994 • narrow layers (pancakes), first noted in LIMS T by Hitchman et al., 1987 • cells extend from equator to subtropics • not uniform in longitude • existence apparently needs presence of planetary waves • are they important for dynamics or transport? condition for instability is normally met at solstice stratopause f2(1-Ri-1)-fuy<0 from Smith and Riese, JGR, 1999