1 / 14

Prof. Dr. Michael Bittner University of Augsburg, Institute of Physics

Proposal for discussion I mpact of s olar-terrestrial magnetic variability on a tmospheric planetary and gravity wave propagation c haracteristics in the upper mesosphere / lower thermosphere (ISAC). Prof. Dr. Michael Bittner University of Augsburg, Institute of Physics

simone
Télécharger la présentation

Prof. Dr. Michael Bittner University of Augsburg, Institute of Physics

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Proposal for discussionImpact of solar-terrestrial magnetic variability on atmospheric planetary and gravity wave propagation characteristics in the upper mesosphere / lower thermosphere (ISAC) Prof. Dr. Michael BittnerUniversity of Augsburg, Institute ofPhysics Dr. Sabine WüstGerman Aerospace Center, DLR, Oberpfaffenhofen Assoc. Partners: A. Semenov (Russia), J. Scheer (Argentina), J. French (Australia), S. Yee, (U.S.A.) SPP workshop “Dynamic Earth” in Potsdam July 3-4, 2014

  2. Planetary Wave Variability Currentlevelofunderstandingof temporal planetarywave variability low high Day WeekMonth Year Decade Century meteorologicalrelevance climaterelevance

  3. Long-term change in pw-activity Integrated statistically significant spectral wavelet intensities per year over all sinusoidalswith periods from 3 to 20 days Derivedfromground-based OH-rotationaltemperaturemeasurements at the UM/LT heightregion NDMC-station: Wuppertal Integrated statistically significant spectral wavelet intensities per year over all sinusoidals from 3 to 20 days [%]

  4. Long-term change in pw-activity Integrated statistically significant spectral wavelet intensities per year over all sinusoidals from 3 to 20 days versus solar magnetic field (Hale cycle) Integrated statistically significant spectral wavelet intensities per year over all sinusoidals from 3 to 20 days [%]Hale cycle [µT] fHöppner & Bittner, 2007

  5. Link between solar (terrestrial) magneticfieldstrengthandpw-activity? We suggest the following physical mechanism – to be further studied in the proposed project ISAC: • Varying solar magnetic field impacts the Earth’s rotation (via Lorentz-Force e.g. on the Earth’s liquid core and thus impacting the terrestrial magnetic field)(z.B. Dehant et al., 1997, Chao et al., 2000) • Earth’s angular velocity is thus modified accordingly (via coupling between the electromagnetic angular momentum between the Earth’s liquid core and the Earth’s mantle)(z.B. Schuh et al., 2003) (fromOort, 1989)

  6. Integrated statistically significant wavelet intensities and fit curve [%] Hale cycle [µT] Long-term change in LOD Day-to-day variation of the length of day (ΔLOD) (from Höppner & Bittner, 2007) Variation ofthelengthofday (ΔLOD) [ms]

  7. Link between solar magneticfieldstrengthandpw-activity? Time series of daily values of the relative westerly angular momentum of the global atmosphere between the surface and 100hPa height (heavy line, scale on right) and the ∆LOD (thin line, scale on left) (Rosen et al., 1987)in units of: fromPeixotoandOort, 1992

  8. Link between solar magneticfieldstrengthandpw-activity? According to Peixoto and Oort, 1992, a change in corresponds with a change in the global-mean zonal wind speed of about The change in LOD during one Hale-cycle is in the order of 3 ms. This means that the “Hale-induced” global-mean zonal wind speed should change in the order of 10 m/s over one Hale cycle.

  9. „Hale-induced“ changes in zonal winds? Mean zonal wind A „Hale-induced“ change in theglobal-mean zonal wind speedisexpectedtobe in theorderofabout10%ofthe zonal background wind field. Summer Winter from Andrews, 2010

  10. „Hale-induced“ modulation in theplanetarywaveverticalpropagationcharacteristics? Mean zonal wind II. Expectedisa considerableimpact on theverticalpropagationconditionforplanetarywaves: Summer Winter A „Hale-induced“ modificationofwouldmodulatetheverticalpropagationofplanetarywavesaccordingtotheir zonal speedvelocities from Andrews, 2010

  11. „Hale-induced“ temperaturetrends in the UM/LT altituderegion? Reportedtemperaturetrends in the UM/LT altituderegionrevealsome latitudinal structure Planetary waveamplitude Erbertseder, Bittner et al., 2006

  12. PW induced Temperature Standard Deviation [K] 7 6 5 4 „Hale-induced“ filteringofatmosphericgravitywaves at the UM/LT region? Gravity waveactivity Yearlymeanplanetarywaveactivity GW induced Temperature Standard Deviation [K] Offermann et al., JASTP, 68, 1924-1933, 2006 Höppner & Bittner., JASTP, 69, 431-448, 2007

  13. Central questionsadressedwithin ISAC • Towhatextentcanweattributetheobservedlongertermchanges in theplanetarywaveactivity in the UM/LT tovariations in the solar-terrestrialmagneticfield? • Towhatextendcanweexplaintheobserved latitudinal temperaturetrendstructure in the UM/LT altituderegionbythe „Hale-induced“ variabilityofplanetarywaves? • Towhatextentistheobservedlongertermchange in thegravitywaveactivity in the UM/LT drivenbythe solar-terrestrialmagneticfield? Data needs: • Solar-terrestrialmagneticfieldvariability („Jerks“): SWARM • Temperatures in the UM/LT altituderegion: TIMED-SABER; NDMC • Zonal winds in themiddleandupperatmosphere: SWARM, SuperDARN

  14. Adressingthecall • Investigatingtheforcingoftheupperatmospherebythe (geo)magneticfield • Understand/quantifycouplingprocessesfrombelowandfromabove • Investigatingpresenttrends

More Related