Gisela Winckler

 





















Gisela Winckler

Lamont-Doherty Earth Observatory

Columbia University

phone (845)365 8756

email winckler(at)ldeo.columbia.edu


I am a physicist and isotope geochemist  interested in climate and biogeochemistry
at the
Lamont-Doherty Earth Observatory,

a key component of the Earth Institute at Columbia University




WHAT’s NEW?


January 24, 2014:

Our new paper in Science (Jan 24, 2014 issue) presents a record of dust supply to the Pacific sector of the Southern Ocean for the past one million years, derived from a suite of deep-sea sediment cores. Dust deposition during glacial periods was 3 times greater than during interglacials. Click here for more information.




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January 14, 2014: Graduate student Ale Borunda passed her Orals. YAY! Congratulations, Ale.



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NEWS ARCHIVE


Michael Kaplan (L-DEO), Kathy Licht (IUPUI) and I have recently started a new project, funded by the National Science Foundation, to study the timing and extent of advances of the East Antarctic ice sheet in the past.

Integrating field work, geochemical analyses and cutting-edge isotope-based dating tools we aim to develop a record of fluctuations in the East Antarctic ice sheet and to identify past changes in both ice sheet flow direction and bedrock composition.


For our blog about the field trip to Antarctica, please click here  or here




View of Mt Howe, Antarctica




DUSTSPEC: Dust records for a changing world


From May 24 - May 26, 2010, Natalie Mahowald (Cornell U), Barbara Maher (U of Lancaster) and I hosted a dust workshop at Lamont-Doherty Earth Observatory:




Please click here to go the DUSTSPEC website which includes the workshop program, a list of attendees, pdfs and short summaries of all presentations

The focus of the workshop was to initiate the next generation dust dataset (called DUSTSPEC), which would include not just two time slices (such as in the highly successful dust data set DIRTMAP), but compile all available dust flux and time information, for dust records globally.  The goal is to improve our global compilation of dust records, over the past glacial cycle (~130kyr), such that we can understand how and why dust properties and fluxes change, and the impacts of these changes on climate and biogeochemistry

For a recent blog about the DUSTSPEC workshop, please click here




March 2010


Our new paper, published in Geophysical Research Letters in March 2010, presents the first observation of mid-ocean ridge hydrothermal activity in the Southern Ocean.











             


        

Image of a black smoker from the                 

                        East Pacific Rise                                        Compilation of known vent sites (German

                                                                                           and van Damm, 2003). So far, no vent sites
                                                                                           were known in the South Pacific South of 38S.

                                                                                           Our results indicate hydrothermal activity along the
                                                                                           Pacific Antarctic Ridge (blue square)

                                                                                               


Analyzing a large tracer data set, collected as part of the World Ocean Circulation Experiment for ocean circulation studies, we identify a previously unobserved locus of hydrothermal venting into the Pacific sector of the Southern Ocean. Combining the geochemical information provided by the helium isotope anomaly (Helium-3 is highly enriched in mantle-derived vent fluids) with independent hydrographic information from the Southern Ocean Database we could trace the source of the hydrothermal input to the Pacific Antarctic Ridge, one of the major global mid-ocean ridge systems, which has until now been a ‘blank spot’ on the global map of hydrothermal venting. Beyond being interesting from a geochemical view point, our results have important oceanographic and climatic implications.


       Click here for a pdf of the paper

       Click here for the news feature/press release



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April 2008


Our new paper, published in Science (April 2008, pre-publication in Science Express in Feb 2008), quantitatively constrains glacial-interglacial dust flux variability in the tropics, a key parameter in dust and climate models, and shows that dust fluxes from interhemispheric sources to the equatorial Pacific have been coherent in timing with dust fluxes to polar regions for the last 500,000 years, suggesting that processes regulating dust generation have a consistent relationship to global climate change.


Click here for a pdf of the paper

Click here for the news feature/press release

Click here for NY Times ‘Week in Science’

For more on dust, ice ages and climate, click here







For a recent (Feb 05) profile of Gisela Winckler, click here