1. The role of MLT dynamics at mid and high latitudes on the Ionosphere/Thermosphere weather (DYNAMITE)
Climatology of semidiurnal lunar and solar tides at mid and high latitudes: interhemispheric comparison
J. L. Chau, G. Stober, F.-J. Lübken, F. Conte, K. Baumgarten, et al.
In collaboration with:
D. Pokhotelov, F. Laskar, P. Hoffmann, N. Pedatella, …
J. F. Conte, J. L. Chau, G. Stober, N. Pedatella, A. Maute, P. Hoffmann, D. Janches, D. Fritts, and D. Murphy
SPP Colloquium , Bremen

2. Main Goals
Quantification of the gravity waves (GW) activity and their corresponding momentum flux in the MLT region with radar and lidar observations at mid and high latitudes.
Investigation of the semidiurnal solar and lunar tides in the MLT region during sudden stratospheric warmings (SSW) and their relation to splitting and displacing stratospheric polar vortex events, using observations and simulations.
Evaluation of the observed MLT solar and lunar tides during SSW and non-SSW events on the I/T weather, by comparing special WACCM-X – TIMEGCM simulations with satellite and ground-based I/T observations.
SPP Colloquium , Bremen

3. Kathrin Baumgarten (see Poster)
T‘ (daily mean) - unfiltered
Vert. filtered (λz< 15 km)
Unfiltered data (i.e. GW plus tides) an vertically filtered data (i.e. mainly inertia GW)
show a
clear minimum during summer
Temporally filtered ( < 8 h)
Short periodic GWs do not show a large variation
No clear annual variation in the temporally filtered data
from Baumgarten et al. [2017]
SPP Colloquium , Bremen

4. Climatology of semidiurnal lunar and solar tides
TIMEGCM/WACCM-X, 90 km (2009 SSW)
SW2
M2 TIMEGCM/WACCM-X, 90 km (2013 SSW)
54N
54S M2
adapted from Pedatella et al. [2014]
from Pedatella et al. [2017], submitted
SPP Colloquium , Bremen

5. Climatology of semidiurnal lunar and solar tides
composites of mean zonal (U) and meridional (V) winds, SW2 and M2 total magnitudes
from Conte et al. [2017], under review
SPP Colloquium , Bremen

6. Climatology of semidiurnal lunar and solar tides
The most active periods of the semidiurnal lunar and solar tides in the SH strongly depend on the geographical location.
M2 shows stronger amplitudes during
Summer, over Davis
Winter, over Rio Grande
Both, observations and simulations show an enhancement of M2 over Rio Grande during 2013 SSW time period.
SPP Colloquium , Bremen

7. Climatology of semidiurnal lunar and solar tides
from Conte et al. [2017], under review
SPP Colloquium , Bremen

8. Dimitry Pokhotelov (see Poster)
Mid-latitude semidiurnal tides
Altitude, km
A12 zonal, m/s
Juliusruh meteor radar data
Altitude, km
A12 zonal, m/s
KMCM simulations
Altitude, km
A12 zonal, m/s
CESM-WACCM simulations
SPP Colloquium , Bremen

9. Semidiurnal solar tides during the fall transition
SPP Colloquium , Bremen
En el HS no es claro el decrecimiento de SW2 durante ninguna de las dos transiciones. Al mirar el comportamiento de los vientos simulados por HAMMONIA (sin procesar), se puede apreciar una clara simetría entre ambas transiciones.
En cambio, en le HN el comportamiento de los vientos no es tan simétrico (e/ las transiciones), destacándose un predominio de eastward wind en octubre, en la estratosfera; mientras que en marzo no es tan intenso el viento eastward. Además, en la mesosfera, en marzo, destaca viento meridional hacia el ecuador.

10. Semidiurnal solar tides during the fall transition
HAMMONIA winds and temp. courtesy of H. Schmidt (MPI, Hamburg)
SPP Colloquium , Bremen
En latitudes medias a altas del HN, durante abril/mayo hay una fuerte variabilidad en la concentración del ozono (que es el principal responsible de la formación de SW2). Esto no se ve en septiembre/octubre (ver paper de Smyshlyaev, University of Saint Petersburg).

11. Thank you!
References
Baumgarten, K., M. Gerding, and F.-J. Lübken (2017), Seasonal variation of gravity wave parameters using different filter methods with daylight lidar measurements at midlatitudes, J. Geophysics. Res. Atmos., 122, 2683–2695, doi: /2016JD
Chau, J. L., P. Hoffmann, N. M. Pedatella, V. Matthias, and G. Stober (2015), Upper mesospheric lunar tides over middle and high latitudes during sudden stratospheric warming events, J. Geophysics. Res. Space Physics, 120, doi: /2015JA
Conte, J. F., C. Brunini (2017), Ingestion of FORMOSAT-3/COSMIC GPS data into La Plata Ionospheric Model: a preliminary assessment, Adv. Spa. Res.,
Conte, J. F., J. L. Chau, G. Stober, N. Pedatella, A. Maute, P. Hoffmann, D. Janches, D. Frits, and D. Murphy (2017), Climatology of semidiurnal lunar and solar tides at mid and high latitudes: interhemispheric comparison, J. Geophysics. Res. Space Physics, Under review.
Pedatella, N. M., H.-L. Liu, F. Sassi, J. Lei, J. L. Chau, and X. Zhang (2014), Ionosphere variability during the 2009 SSW: Influence of the lunar semidiurnal tide and mechanisms producing electron density variability, J. Geophys. Res. Space Physics, 119, 3828–3843, doi: /2014JA
Pedatella, N. M., J. L. Chau, H. Schmidt, L. P. Goncharenko, C. Stolle, K. Hocke, V. L. Harvey, B. Funke, and T. A. Siddiqui (2017), The Far-Flung Effects of Sudden Stratospheric Warmings, EOS, Submitted.