Studies of mesospheric radar echoes at polar and middle latitudes

During summer months, at mid and polar latitudes very strong non-turbulent related VHF-radar echoes are observed at mesospheric altitudes (80-90 km), that are called Mesosperic Summer Echoes (MSE). At polar latitudes (PMSE) they occur more often and are stronger then their midlatitude counterparts. On the other hand, winter echoes (PMWE and MWE) are more seldom observed below 80 km during equinoctial and winter months, and are believed to be related to turbulence.

At IAP we have observed PMSE and PMWE with the ALOMAR SOUSY Radar (1994-1997) the ALWIN-VHF-Radar (1999-2008) and MAARSY (since 2010) at Andenes, whereas the MSE and MWE are measured with the OSWIN-VHF-Radar at Kühlungsborn since 1998. Our investigations related to these echoes, among others, are:

  • the seasonal and diurnal variation of the PMSE/MSE frequency, influence of temperature, meridional wind, water vapour, turbulence, tidal waves and ionization,
  • the influence of atmospheric waves upon the creation of discrete layers in PMSE,
  • the connection between PMSE/MSE and noctilucent clouds (NLC), since in both phenomena ice particles play an essential role,
  • the investigation of long-term variations of (P)MSE (seasonal duration and strength),
  • the dependence of (P)MSE on geographic latitude and longitude by means of absolutely calibrated VHF-Radars (e.g., interhemispheric differences).


Furthermore some of our studies are complemented by in-situ measurements during rocket campaigns (e.g., ROMA, ECOMA, WADIS).

Publications

  • J. L. Chau, J. Röttger und M. Rapp, PMSE strength during enhanced D region electron densities: Faraday rotation and absorption effects at VHF frequencies, J. Atmos. Solar-Terr. Phys., doi:10.1016/j.jastp.2013.06.015, 2014
  • S. Sommer, G. Stober, C. Schult, M. Zecha und R. Latteck, Investigation of horizontal structures at mesospheric altitudes using coherent radar imaging, Adv. Radio Sci., 11, 319-325, doi:10.5194/ars-11-1-2013, 2013
  • R. Latteck und J. Bremer, Long-term changes of polar mesosphere summer echoes at 69°N, J. Geophys. Res., doi:10.1002/jgrd.50787, 2013
  • R. Latteck, W. Singer, M. Rapp, T. Renkwitz und G. Stober, Horizontally resolved structures of radar backscatter from polar mesospheric layers, Adv. Radio Sci., 10, 285-290, doi:10.5194/ars-10-285-2012, 2012.
  • Q. Li und M. Rapp, PMSE-observations with the EISCAT VHF and UHF-Radars: Statistical properties, J. Atmos. Solar-Terr. Phys., 73, 944-956, doi:10.1016/j.astp.2010.05.015, 2011.
  • I. Strelnikova und M. Rapp, Majority of PMSE spectral widths at UHF and VHF are compatible with a single scattering mechanism, J. Atmos. Solar-Terr. Phys., 2142-2152, doi:10.1016/j.jastp.2010.11.025, 2011
  • M. Rapp, R. Latteck, G. Stober, P. Hoffmann, W. Singer und M. Zecha, First three-dimensional observations of polar mesosphere winter echoes: Resolving space-time ambiguity, J. Geophys. Res., 116, A11307, doi:10.1029/2011JA016858, 2011
  • J. Bremer, P. Hoffmann, R. Latteck, W. Singer und M. Zecha, Long-term changes of (polar) mesosphere summer echoes, J. Atmos. Solar-Terr. Phys., 1571-1576, doi:10.1016/jastp.2009.03.010, 2009
  • M. Zecha und J. Röttger, Occurence of polar mesosphere summer echoes at very high latitudes, Ann. Geophys., 27(3), 1331-1342, doi:10.5194/angeo-27-1331-2009, 2009
  • R. Latteck, W. Singer, R. J. Morris, W. K. Hocking, D. J. Murphy, D. A. Holdsworth und N. Swarnalingam, Similarities and differences in polar mesosphere summer echoes observed in the Arctic and Antarctica, Ann. Geophys., 26, 2795-2806, doi:10.5194/angeo-26-2795-2008, 2008
  • M. Rapp, I. Strelnikova, R. Latteck, P. Hoffmann, U.-P. Hoppe, I. Häggström und M. Rietveld, Polar mesosphere summer echoes (PMSE) studied at Bragg wavelengths of 2.8 m, 67 cm, and 16 cm, J. Atmos. Solar-Terr. Phys., 70, 947-961, doi:10.1016/j.jastp.2007.11.005, 2008