 |
| Titel |
Mesoscale temperature fluctuations in the stratosphere |
| VerfasserIn |
B. L. Gary |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 6, no. 12 ; Nr. 6, no. 12 (2006-10-12), S.4577-4589 |
| Datensatznummer |
250004138
|
| Publikation (Nr.) |
 copernicus.org/acp-6-4577-2006.pdf |
|
|
|
|
|
| Zusammenfassung |
| An airborne instrument that measures altitude temperature profiles is
ideally suited for the task of characterizing statistical properties of the
vertical displacement of isentrope surfaces. Prior measurements of
temperature fluctuations during level flight could not be used to infer
isentrope altitude variations because lapse rate information was missing.
The Microwave Temperature Profiler instrument, which includes lapse rate
measurements at flight level as a part of temperature profiles, has been
used on hundreds of flights to produce altitude versus ground track
cross-sections of potential temperature. These cross-sections show isentrope
altitude variations with a horizontal resolution of ~3 km for a >6 km
altitude region. An airborne isentrope-altitude cross-section (IAC) can
be compared with a counterpart IAC generated from synoptic scale data, based
on radiosondes and satellite instruments, in order to assess differences
between the altitudes of isentrope surfaces sampled at mesoscale versus
synoptic scale. It has been found that the synoptic scale isentropes fail to
capture a significant component of vertical displacement of isentrope
surfaces, especially in the vicinity of jet streams. Under the assumptions
that air parcels flow along isentrope surfaces, and change temperature
adiabatically while undergoing altitude displacements, it is possible to
compute mesoscale temperature fluctuations that are not present in synoptic
scale back trajectory parcel temperature histories. It has been found that
the magnitude of the mesoscale component of temperature fluctuations varies
with altitude, season, latitude and underlying topography. A model for these
dependences is presented, which shows, for example, that mesoscale
temperature fluctuations increase with altitude in a systematic way, are
greatest over mountainous terrain, and are greater at polar latitudes during
winter. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|