Show simple item record

dc.contributor.author
Kienast-Sjögren, Erika
dc.contributor.author
Rolf, Christian
dc.contributor.author
Seifert, Patric
dc.contributor.author
Krieger, Ulrich K.
dc.contributor.author
Luo, Bei P.
dc.contributor.author
Krämer, Martina
dc.contributor.author
Peter, Thomas
dc.date.accessioned
2018-10-30T13:35:05Z
dc.date.available
2017-06-12T08:19:16Z
dc.date.available
2018-10-30T13:35:05Z
dc.date.issued
2016
dc.identifier.issn
1680-7375
dc.identifier.issn
1680-7367
dc.identifier.other
10.5194/acp-16-7605-2016
en_US
dc.identifier.uri
http://hdl.handle.net/20.500.11850/117879
dc.identifier.doi
10.3929/ethz-b-000117879
dc.description.abstract
Cirrus, i.e., high, thin clouds that are fully glaciated, play an important role in the Earth's radiation budget as they interact with both long- and shortwave radiation and affect the water vapor budget of the upper troposphere and stratosphere. Here, we present a climatology of midlatitude cirrus clouds measured with the same type of ground-based lidar at three midlatitude research stations: at the Swiss high alpine Jungfraujoch station (3580ma.s.l.), in Zürich (Switzerland, 510ma.s.l.), and in Jülich (Germany, 100ma.s.l.). The analysis is based on 13000h of measurements from 2010 to 2014. To automatically evaluate this extensive data set, we have developed the Fast LIdar Cirrus Algorithm (FLICA), which combines a pixel-based cloud-detection scheme with the classic lidar evaluation techniques. We find mean cirrus optical depths of 0.12 on Jungfraujoch and of 0.14 and 0.17 in Zürich and Jülich, respectively. Above Jungfraujoch, subvisible cirrus clouds (τ < 0.03) have been observed during 6% of the observation time, whereas above Zürich and Jülich fewer clouds of that type were observed. Cirrus have been observed up to altitudes of 14.4kma.s.l. above Jungfraujoch, whereas they have only been observed to about 1km lower at the other stations. These features highlight the advantage of the high-altitude station Jungfraujoch, which is often in the free troposphere above the polluted boundary layer, thus enabling lidar measurements of thinner and higher clouds. In addition, the measurements suggest a change in cloud morphology at Jungfraujoch above ∼ 13km, possibly because high particle number densities form in the observed cirrus clouds, when many ice crystals nucleate in the high supersaturations following rapid uplifts in lee waves above mountainous terrain. The retrieved optical properties are used as input for a radiative transfer model to estimate the net cloud radiative forcing, CRFNET, for the analyzed cirrus clouds. All cirrus detected here have a positive CRFNET. This confirms that these thin, high cirrus have a warming effect on the Earth's climate, whereas cooling clouds typically have cloud edges too low in altitude to satisfy the FLICA criterion of temperatures below −38°C. We find CRFNET = 0.9Wm−2 for Jungfraujoch and 1.0Wm−2 (1.7Wm−2) for Zürich (Jülich). Further, we calculate that subvisible cirrus (τ < 0.03) contribute about 5%, thin cirrus (0.03 < τ < 0.3) about 45%, and opaque cirrus (0.3 < τ) about 50% of the total cirrus radiative forcing.
en_US
dc.format
application/pdf
en_US
dc.language.iso
en
en_US
dc.publisher
Copernicus
en_US
dc.rights.uri
http://creativecommons.org/licenses/by/3.0/
dc.title
Climatological and radiative properties of midlatitude cirrus clouds derived by automatic evaluation of lidar measurements
en_US
dc.type
Journal Article
dc.rights.license
Creative Commons Attribution 3.0 Unported
dc.date.published
2016-06-22
ethz.journal.title
Atmospheric Chemistry and Physics
ethz.journal.volume
16
en_US
ethz.journal.issue
12
en_US
ethz.journal.abbreviated
Atmos. chem. phys.
ethz.pages.start
7605
en_US
ethz.pages.end
7621
en_US
ethz.version.deposit
publishedVersion
en_US
ethz.identifier.wos
ethz.identifier.scopus
ethz.identifier.nebis
004294181
ethz.publication.place
Göttingen
en_US
ethz.publication.status
published
en_US
ethz.leitzahl
ETH Zürich::00002 - ETH Zürich::00012 - Lehre und Forschung::00007 - Departemente::02350 - Dep. Umweltsystemwissenschaften / Dep. of Environmental Systems Science::02717 - Institut für Atmosphäre und Klima / Inst. Atmospheric and Climate Science::03517 - Peter, Thomas / Peter, Thomas
en_US
ethz.leitzahl.certified
ETH Zürich::00002 - ETH Zürich::00012 - Lehre und Forschung::00007 - Departemente::02350 - Dep. Umweltsystemwissenschaften / Dep. of Environmental Systems Science::02717 - Institut für Atmosphäre und Klima / Inst. Atmospheric and Climate Science::03517 - Peter, Thomas / Peter, Thomas
ethz.date.deposited
2017-06-12T08:21:57Z
ethz.source
ECIT
ethz.identifier.importid
imp59365481ec68b10325
ethz.ecitpid
pub:179809
ethz.eth
yes
en_US
ethz.availability
Open access
en_US
ethz.rosetta.installDate
2017-07-20T17:17:58Z
ethz.rosetta.lastUpdated
2020-02-15T15:41:47Z
ethz.rosetta.versionExported
true
ethz.COinS
ctx_ver=Z39.88-2004&amp;rft_val_fmt=info:ofi/fmt:kev:mtx:journal&amp;rft.atitle=Climatological%20and%20radiative%20properties%20of%20midlatitude%20cirrus%20clouds%20derived%20by%20automatic%20evaluation%20of%20lidar%20measurements&amp;rft.jtitle=Atmospheric%20Chemistry%20and%20Physics&amp;rft.date=2016&amp;rft.volume=16&amp;rft.issue=12&amp;rft.spage=7605&amp;rft.epage=7621&amp;rft.issn=1680-7375&amp;1680-7367&amp;rft.au=Kienast-Sj%C3%B6gren,%20Erika&amp;Rolf,%20Christian&amp;Seifert,%20Patric&amp;Krieger,%20Ulrich%20K.&amp;Luo,%20Bei%20P.&amp;rft.genre=article&amp;rft_id=info:doi/10.5194/acp-16-7605-2016&amp;
 Search print copy at ETH Library

Files in this item

Thumbnail

Publication type

Show simple item record