View source for Willi Dansgaard

{{Short description|Danish paleoclimatologist  (1922–2011)}}
{{Infobox scientist
| honorific_prefix  = 
| name              = Willi Dansgaard
| birth_date        = {{birth date|1922|08|30|df=y}}
| birth_place       = [[Copenhagen]], Denmark
| death_date        = {{death date and age|2011|01|8|1922|08|30|df=y}} 
| death_place       = Copenhagen, Denmark
| nationality       = Danish
| fields            = Paleoclimatology 
| workplaces        =[[Copenhagen University]]
}}
'''Willi Dansgaard''' (30 August 1922<ref>{{cite web|url=https://www.latimes.com/science/la-me-willi-dansgaard-20110207-story.html|title=Willi Dansgaard dies at 88; scientist who recognized climate record in ice cap|first=Thomas H. Maugh|last=II|date=7 February 2011|publisher=|via=LA Times}}</ref> – 8 January 2011<ref>{{cite web |url=http://www.dmi.dk/dmi/nekrolog__professor_emer.__dr._phil._willi_dansgaard_er_d_d |title=Nekrolog: Professor emer., Dr. Phil. Willi Dansgaard er død |accessdate=2011-01-14 |url-status=dead |archiveurl=https://web.archive.org/web/20110114073204/http://www.dmi.dk/dmi/nekrolog__professor_emer.__dr._phil._willi_dansgaard_er_d_d |archivedate=2011-01-14 }}</ref>) was a [[Denmark|Danish]] [[paleoclimatologist]].  He was Professor Emeritus of Geophysics at the [[University of Copenhagen]] and a member of the [[Royal Danish Academy of Science and Letters]], the [[Royal Swedish Academy of Sciences]], the [[Icelandic Academy of Sciences]], and the [[Danish Geophysical Society]].

==Early life and career==
Dansgaard grew up in Copenhagen, to parents who owned an [[engraving]] shop. In 1947, he graduated from the [[University of Copenhagen]], winning a gold medal for his thesis on X-ray [[dosimetry]].<ref name="JPS_Obit">{{Cite journal |url=https://www.cambridge.org/core/journals/polar-record/article/willi-dansgaard/16626A5BA1F8F35488630C56CFFE8575
|title=Willi Dansgaard
|last=Steffensen
|first=Jørgen Peder
|journal=Polar Record
|quote=Willi Dansgaard, a great pioneer of climate research, died on 8 January 2011 at the age of 88. He was born on 30 August 1922 and grew up in the centre of Copenhagen where his parents had an engraving shop. He finished his university degree in physics, mathematics and astronomy in 1947 with a gold medal award for a thesis on X-ray dosimetry at the Biophysics Laboratory of the University of Copenhagen.
|date=24 March 2011
|volume=48
|issue=2
|pages=206–207
|doi=10.1017/S0032247411000155
|s2cid=233320475
|access-date=9 July 2021|doi-access=free
}}</ref>

After several years of research, including some at sites in [[Greenland]], Dansgaard returned to the [[University of Copenhagen]]'s Biophysics Laboratory, where he developed its [[mass spectrometer]] to analyse water [[isotopes]]. According to his student [[Jørgen Peder Steffensen]]:<ref name="JPS_Obit"/>
<blockquote>In June 1952, Dansgaard made a discovery that came to influence the rest of his scientific career. He discovered that it was possible to determine the temperature of the precipitating clouds by analysing the stable isotopic composition of rain water. In the following 12 years, he systematically collected water samples from all over the world in collaboration with the [[Danish East India Company|Danish East Asia Company]], contacts in Greenland, a French expedition under [[Paul Emile Victor]] and later the [[International Atomic Energy Agency]] and [[World Meteorological Organization]].</blockquote>

== Overview ==

Dansgaard was the first paleoclimatologist to demonstrate that measurements of the trace isotopes [[oxygen-18]] and [[deuterium]] in accumulated [[glacier]] ice could be used as an indicator of past climate.  Dansgaard was the first to note deuterium excess, or a water sample's deviation from the global meteoric water line (GMWL) in ice cores. He found that the kinetic differences between [[hydrogen-1]] and deuterium related to the temperature of source water, and the absolute humidity.<ref name="NYT_Obit2011">{{Cite news |url=https://www.nytimes.com/2011/01/29/world/europe/29dansgaard.html 
|title=Willi Dansgaard Dies at 88; Read Climates in Old Ice 
|last=Martin |first=Douglas |work=NY Times
|quote=He discovered that as clouds rise and cool, heavier forms of oxygen (or isotopes — those with more neutrons) will react to the cold sooner, condensing and falling back to earth as precipitation before lighter ones do; a preponderance of heavier oxygen molecules would then indicate colder atmospheric temperatures. 
|date=January 28, 2011
 |access-date=February 6, 2022}}</ref>  

He was the first scientist to extract palaeoclimatic information from the American [[Camp Century]] ice core from [[Greenland]] drilled by the US army [[Cold Regions Research and Engineering Laboratory]] (CRREL).  Dansgaard also took a leading role in the drilling of the first ice core to bedrock for scientific reasons, the [[Dye 3|DYE-3]] core from [[South Greenland]], {{convert|1400|km|mi}} from the Camp Century. Confirming findings from the analysis of the Camp Century ice core, the DYE-3 climate profile documented the existence of rapid climate change, during and at the end of the last glacial. The repeated events of [[abrupt climate change]] during the glacial are named after Willi Dansgaard and his Swiss colleague, [[Hans Oeschger]], and are known as [[Dansgaard–Oeschger event]]s.

== Awards ==
* 1971 [[Hans Egede Medal]]
* 1975 [[Swedish Society for Anthropology and Geography]]'s [[Vega medal]]
* 1976 [[Seligman Crystal]] from the [[International Glaciological Society]]<ref> {{cite web|url=https://www.igsoc.org/awards/seligman/b|title=The Seligman Crystal|publisher=International Glaciological Society|accessdate=30 November 2016}}{{dead link|date=November 2017 |bot=InternetArchiveBot |fix-attempted=yes }} </ref>
* 1995 [[Royal Swedish Academy of Sciences]] [[Crafoord Prize]]
* 1996 [[Tyler Prize for Environmental Achievement]], [https://web.archive.org/web/20040828020647/http://www.usc.edu/dept/LAS/tylerprize/dansgard.html 1996]

==Notes==
{{Reflist}}

==External links==
* [https://archive.today/20120524113402/http://content.aip.org/products/esva/Dansgaard_Willi.html - photo of Dansgaard], [[Chester C. Langway]] and [[Hans Oeschger]]
* [https://icedrill.org/sites/default/files/FrozenAnnals.pdf - Dansgaard's 2005 autobiography "Frozen Annals, Greenland Ice Sheet Research"]
* [https://web.archive.org/web/20040621160546/http://calspace.ucsd.edu/virtualmuseum/climatechange2/07_2.shtml "Carbon Dioxide Through the Ice Ages' from UCSD (archived 2004)]
* [https://web.archive.org/web/20090927094453/http://www.nbi.ku.dk/english/history/geophysics/history_danish_ice_core "History of Danish ice core research" from Niels Bohr Institute (archived 2009)]

{{Authority control}}
{{DEFAULTSORT:Dansgaard, Willi}}
[[Category:1922 births]]
[[Category:2011 deaths]]
[[Category:Danish climatologists]]
[[Category:Paleoclimatologists]]
[[Category:Members of the Royal Swedish Academy of Sciences]]


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