|Faculty of Physics and Earth Science||
Middle and Upper Atmosphere
The mesosphere/lower thermosphere (MLT) is one of the scientifically
most challenging regions of the atmosphere.
The MLT is the region where wave-wave and wave-mean flow interaction processes
lead to a mean circulation regime
that is extremely far from radiative equilibrium.
Although radar measurements of MLT winds are possible since more than half a
century, our current knowledge on MLT dynamics
is still far from complete, mostly due to incomplete coverage of the global wind
field by ground-based remote sensing system.
As a contribution to our knowledge of MLT dynamics a SKiYMET meteor radar is operated at Collm Observatory (51.3°N, 13°E) continuously since August 2004. The measurements deliver hourly wind information in the height range 80-100 km and daily mean temperatures near the mesopause. Together with the earlier LF wind measurements peformed at Collm 1959-2008 a unique MLT circulation parameter dataset is available.
Collm radar transmit Antenna 2004-2015, now replaced by a crossed dipole antenna
6-year mean zonal prevailing winds over Collm as measured with meteor radar
Jacobi, Ch., T. Ermakova, D. Mewes, and A.I. Pogoreltsev, 2017: El Niño influence on the mesosphere/lower thermosphere circulation at midlatitudes as seen by a VHF meteor radar at Collm (51.3°N, 13°E), Adv. Radio Sci., in press, corrected proof.
Jacobi, Ch., F. Lilienthal, C. Geißler, and A. Krug, 2015: Long-term variability of mid-latitude mesosphere-lower thermosphere winds over Collm (51°N, 13°E), J. Atmos. Sol.-Terr. Phys., 136, B, 174–186, doi:10.1016/j.jastp.2015.05.006.
Lilienthal, F., and Ch. Jacobi, 2015: Meteor radar quasi two-day wave observations over 10 years at Collm (51.3°N, 13.0°E), Atmos. Chem. Phys., 15, 9917-9927, doi:10.5194/acp-15-9917-2015.
Jacobi, Ch., 2014: Meteor heights during the recent solar minimum, Adv. Radio Sci., 12, 161-165.
Jacobi, Ch., C. Arras, and J. Wickert, 2013: Enhanced sporadic E occurrence rates during the Geminid meteor showers 2006-2010, Adv. Radio Sci., 11. 313-318.
Jacobi, Ch., 2012: 6 year mean prevailing winds and tides measured by VHF meteor radar over Collm (51.3°N, 13.0°E). J. Atmos. Solar-Terr. Phys., 78–79, 8–18, doi:10.1016/j.jastp.2011.04.01.
Placke, M., P. Hoffmann, E. Becker, Ch. Jacobi, W. Singer, and M. Rapp, 2011: Gravity wave momentum fluxes in the MLT – Part II: Meteor radar investigations at high and midlatitudes in comparison with modeling studies. J. Atmos. Solar–Terr. Phys., 73, 911-920, doi:10.1016/j.jastp.2010.05.007.
Placke, M., G. Stober, and Ch. Jacobi, 2010: Gravity wave momentum fluxes in the MLT—Part I: Seasonal variation at Collm (51.3°N, 13.0°E). J. Atmos. Solar–Terr. Phys., 73, 904-910, doi:10.1016/j.jastp.2010.07.012.
Stober, G., Ch. Jacobi, and W. Singer, 2011: Meteoroid mass determination from underdense trails. J. Atmos. Solar-Terr. Phys., 73, 895-900, doi:10.1016/j.jastp.2010.06.009.
Arras, C., Ch. Jacobi, and J. Wickert, 2009: Semidiurnal tidal signature in sporadic E occurrence rates derived from GPS radio occultation measurements at midlatitudes. Ann. Geophys. 27, 2555–2563.
Jacobi, Ch., C. Arras, D. Kürschner, W. Singer, P. Hoffmann, and D. Keuer, 2009: Comparison of mesopause region meteor radar winds, medium frequency radar winds and low frequency drifts over Germany. Adv. Space. Res., 43, 247-252.
Last update 26 January 2017 by Ch. Jacobi