Webbläsaren som du använder stöds inte av denna webbplats. Alla versioner av Internet Explorer stöds inte längre, av oss eller Microsoft (läs mer här: * https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Var god och använd en modern webbläsare för att ta del av denna webbplats, som t.ex. nyaste versioner av Edge, Chrome, Firefox eller Safari osv.

Default user image.

Markku Rummukainen

Professor

Default user image.

Lidar observation of spherical particles in a -65°cold cirrus observed above Sodankyla (Finland) during S.E.S.A.M.E.

Författare

  • Massimo Del Guasta
  • Marco Morandi
  • Leopoldo Stefanutti
  • Stefano Balestri
  • Esko Kyro
  • Markku Rummukainen
  • Rigel Kivi
  • Vincenzo Rizi
  • Bernhard Stein
  • Carsten Wedekind
  • Bernd Mielke
  • Renaud Matthey
  • Valentin Mitev
  • Mathilde Douard
Visa allt

Summary, in English

The absence of LIDAR depolarization in a polar cirrus observed above Sodankyla (Finland) showed the presence of spherical particles at -65°C. The presence of pure liquid water is excluded, since homogeneous freezing should occur at or above -40°C. The cirrus layer was detected at the tropopause, during the horizontal and vertical advection above northern Scandinavia of warm and wet oceanic air. Two alternative explanations are suggested, the first one involving the presence of large, deliquescent tropospheric CN, freezing at very low temperature, and the second one involving the presence of metastable, spherical ice-particles produced in the fast adiabatic cooling of the airmasses. The second hypothesis is less reasonable because the absence of depolarized LIDAR signal implies a strict cylindrical symmetry in the particles, a symmetry that is difficult to maintain during the freezing process.

Publiceringsår

1998

Språk

Engelska

Sidor

357-374

Publikation/Tidskrift/Serie

Journal of Aerosol Science

Volym

29

Avvikelse

3

Dokumenttyp

Artikel i vetenskaplig tidskrift

Förlag

Elsevier

Aktiv

Published

ISBN/ISSN/Övrigt

  • ISSN: 0021-8502