 |
| Titel |
Statistics of lower tropospheric inversions over the continental United States |
| VerfasserIn |
Y. H. Zhang, S. D. Zhang, F. Yi, Z. Y. Chen |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
0992-7689
|
| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 29, no. 2 ; Nr. 29, no. 2 (2011-02-22), S.401-410 |
| Datensatznummer |
250016979
|
| Publikation (Nr.) |
 copernicus.org/angeo-29-401-2011.pdf |
|
|
|
|
|
| Zusammenfassung |
| The basic structure parameters of lower tropospheric
inversions (LTIs) have been derived from 10 years (1998–2007) of high vertical
resolution (~50 m) radiosonde observations over 56 United States
stations. Seasonal and longitudinal variability of these parameters are
presented and the formation mechanisms of LTI are also discussed. It is
found that LTI seems to be a common feature over the continental United
States. The LTI occurrence rates (defined as the fraction of measurements
with LTI, which is calculated from the number of LTI cases divided by the
number of measurements of the whole 10 years) at these 56 stations vary from
3.7% to 14.5%; the averaged base heights of LTI have a range of 3–5 km
above mean sea level (a.m.s.l.); the averaged thicknesses and temperature jump
ranges from 420–465 m and 1.9–2.2 K, respectively. These parameters have an
obvious seasonal variation. In winter, all the occurrence rates, thicknesses
and temperature jumps of LTI have much larger values than those in summer.
LTI occurrence rate shows an obvious west-east increasing trend in all 4
seasons. Detailed analyses reveal that dynamical instability induced by
strong zonal wind shear is responsible for LTI in winter, spring and autumn;
the frontal system tends to generate LTI in summer. Since the higher
occurrence rate, larger temperature jump and larger thickness of LTI occur
in winter, we believe strong zonal wind shear plays a more important role in
the formation of LTI. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|