 |
| Titel |
Momentum-flux intermittency and energy spectra from a stochastic parameterization of non-orographic gravity waves |
| VerfasserIn |
Alvaro de la Camara, François Lott, Albert Hertzog |
| Konferenz |
EGU General Assembly 2014
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250092845
|
| Publikation (Nr.) |
 EGU/EGU2014-7209.pdf |
|
|
|
|
|
| Zusammenfassung |
| Momentum flux intermittency and global energy spectra of gravity waves (GWs) generated by a stochastic, multiwave parameterization of non-orographic GWs are studied. To that aim, offline experiments are conducted using dynamical fields from reanalysis datasets. A key point of the study is to constrain the free parameters of the scheme using observations of GW intermittency from long-duration balloon flights over Antarctica during the Concordiasi campaign in 2010. As a consequence, the parameterized GWs show intermittency characteristics of absolute momentum flux that qualitavely agree with recent global observations by satellite instruments, specially in the extratropics. The results show the importance of a stochastic approach for a better representation of the observed intermittency in the GW field.
Additionally, we aim to reconcile the two different approaches more commonly followed in non-orographic GW parameterizations, namely the multiwave and the spectral schemes. For this purpose, it is shown that the observed universal spectra of GWs as a function of the vertical wavenumber, which is on the basis of some spectral parameterizations, can be obtained as a superposition of individual, narrow-banded periodograms represented in our multiwave parameterization. |
|
|
|
|
|
|