Bibliography

Space shuttle exhaust plumes in the lower thermosphere: Advective transport and diffusive spreading

The space shuttle main engine plume deposited between 100 and 115\ km altitude is a valuable tracer for global-scale dynamical processes. Several studies have shown that this plume can reach the Arctic or Antarctic to form bursts of polar mesospheric clouds (PMCs) within a few days. The rapid transport of the shuttle plume is currently not reproduced by general circulation models and is not well understood. To help delineate the issues, we present the complete satellite datasets of shuttle plume observations by the Sounding of the Atmosphere using Broadband Emission Radiometry instrument and the Sub-Millimeter Radiometer instrument. From 2002 to 2011 these two instruments observed 27 shuttle plumes in over 600 limb scans of water vapor emission, from which we derive both advective meridional transport and diffusive spreading. Each plume is deposited at virtually the same place off the United States east coast so our results are relevant to northern mid-latitudes. We find that the advective transport for the first 6\textendash18\ h following deposition depends on the local time (LT) of launch: shuttle plumes deposited later in the day (~13\textendash22 LT) typically move south whereas they otherwise typically move north. For these younger plumes rapid transport is most favorable for launches at 6 and 18 LT, when the displacement is 10\textdegree in latitude corresponding to an average wind speed of 30\ m/s. For plumes between 18 and 30\ h old some show average sustained meridional speeds of 30\ m/s. For plumes between 30 and 54\ h old the observations suggest a seasonal dependence to the meridional transport, peaking near the beginning of year at 24\ m/s. The diffusive spreading of the plume superimposed on the transport is on average 23\ m/s in 24\ h. The plume observations show large variations in both meridional transport and diffusive spreading so that accurate modeling requires knowledge of the winds specific to each case. The combination of transport and spreading from the STS-118 plume in August 2007 formed bright PMCs between 75 and 85\textdegreeN a day after launch. These are the highest latitude Arctic PMCs formed by shuttle exhaust reported to date.

Stevens, Michael; Lossow, Stefan; Siskind, David; Meier, R.R.; Randall, Cora; Russell, James; Urban, Jo; Murtagh, Donal;

Published by: Journal of Atmospheric and Solar-Terrestrial Physics      Published on: 02/2014

YEAR: 2014     DOI: 10.1016/j.jastp.2013.12.004

Atmospheric dynamics; Lower thermosphere; Polar mesospheric clouds; Space shuttle exhaust

Nonmigrating tidal signatures in the magnitude and the inter-hemispheric asymmetry of the equatorial ionization anomaly

Based on nine years of observations from the satellites CHAMP and GRACE the tidal signatures in the magnitude and the inter-hemisphere asymmetry of the equatorial ionization anomaly (EIA) have been investigated in this study. The EIA magnitude parameters show longitudinal wavenumber 4 and 3 (WN4/WN3) patterns during the months around August and December, respectively, while for different EIA parameters the contributions of the various tidal parameters are different. For the crest- to-trough ratio (CTR) the dominating nonmigrating tidal component contributing to WN4 is DE3 during the months around August, while during the months around December solstice the stationary planetary wave, SPW3, takes a comparable role to DE2 in contributing to WN3. For the apex height index (ApexHC) of the EIA fluxtube the stationary planetary waves, SPW4/SPW3, exceed the amplitudes of DE3/DE2 taking the leading role in causing the longitudinal WN4/WN3 patterns. During the\  months around December solstice the SW3 tide is prominent in both CTR and ApexHC. SW3 shows a strong dependence on the solar flux level, while it is hardly dependent on magnetic activity. For the EIA interhemispheric asymmetry only WN1 and WN2 longitudinal patterns can be seen. During June solstice months the pattern can be explained by stationary planetary waves SPW1 and SPW2. Conversely, around December solstice months longitudinal features exhibit some local time evolution,\  in particular the diurnal nonmigrating tide D0 takes the leading role.

Xiong, C.; Lühr, H.;

Published by: Annales Geophysicae      Published on: 01/2013

YEAR: 2013     DOI: 10.5194/angeo-31-1115-2013

Atmospheric dynamics; Equatorial ionosphere; Ionosphere; ionosphere\textendashatmosphere interactions. Meteorology