Jean Lynch-Stieglitz

Last updated
Jean Lynch-Stieglitz
Alma materColumbia University
Scientific career
InstitutionsGeorgia Institute of Technology
Thesis Controls on the isotopic composition of oceanic carbon and applications to paleoceanographic reconstruction  (1995)

Jean Lynch-Stieglitz is a paleoceanographer known for her research on reconstructing changes in ocean circulation over the last 100,000 years.

Contents

Education and career

An interest in the natural world, combined with the logic of science and math, attracted Lynch-Stieglitz to science and after a summer at the Duke University Marine Laboratory she decided on a career in physical oceanography. [1] In 1986, she earned B.S. degrees in physics and geology from Duke University [2] and for two years she worked as an oceanographer at the Pacific Marine Environmental Laboratory. From 1988 until 1989 she worked at the Maryland Science Center and as a programmer at Johns Hopkins University before moving to Columbia University where she earned an M.A. (1991) and Ph.D. (1995) in geological sciences. [3] After two years as a postdoctoral scholar at Woods Hole Oceanographic Institution, in 1996 she returned to New York where she joined the faculty of the Lamont–Doherty Earth Observatory. In 2004, Lynch-Stieglitz moved to the Georgia Institute of Technology where she was promoted to professor in 2010. [3]

From 2012 to 2015, Lynch-Stieglitz was the Editor of Earth and Planetary Science Letters. [4]

In 2015 Lynch-Stieglitz was elected a fellow of the American Association for the Advancement of Science "for bringing physical oceanography approaches to the study of transient circulation changes during ice ages, providing a window into the ocean’s interaction with today’s climate change." [5]

Research

Lynch-Stieglitz's research links the ocean and climate over the past 100,000 years. She has used carbon isotopes in benthic foraminifera to reconstruct air-sea exchange in carbon isotopes, [6] changes in the movement of deep water masses, [7] and Antarctic Intermediate Water in the transitions between glacial and interglacial periods. [8] In the Atlantic Ocean, she has examined movement of the Gulf Stream during the Last Glacial Maximum [9] and linked changes in the Atlantic meridional overturning circulation and to rapid changes in climate. [10] [11] [12] Her research also extends to regions where ice alters the exchange of carbon dioxide between atmosphere and ocean in glacial periods, [13] and work in the Pacific Ocean where she has examined sea surface temperatures from the Last Glacial Maximum to the present. [14]

Selected publications

Awards and honors

Related Research Articles

The Younger Dryas, which occurred circa 12,900 to 11,700 years BP, was a return to glacial conditions which temporarily reversed the gradual climatic warming after the Last Glacial Maximum (LGM), which lasted from circa 27,000 to 20,000 years BP. The Younger Dryas was the last stage of the Pleistocene epoch that spanned from 2,580,000 to 11,700 years BP and it preceded the current, warmer Holocene epoch. The Younger Dryas was the most severe and long lasting of several interruptions to the warming of the Earth's climate, and it was preceded by the Late Glacial Interstadial, an interval of relative warmth that lasted from 14,670 to 12,900 BP.

<span class="mw-page-title-main">Dansgaard–Oeschger event</span> Rapid climate fluctuation in the last glacial period.

Dansgaard–Oeschger events, named after palaeoclimatologists Willi Dansgaard and Hans Oeschger, are rapid climate fluctuations that occurred 25 times during the last glacial period. Some scientists say that the events occur quasi-periodically with a recurrence time being a multiple of 1,470 years, but this is debated. The comparable climate cyclicity during the Holocene is referred to as Bond events.

Carbon (6C) has 15 known isotopes, from 8
C
 to 22
C
, of which 12
C
 and 13
C
 are stable. The longest-lived radioisotope is 14
C
, with a half-life of 5.70(3)×103 years. This is also the only carbon radioisotope found in nature, as trace quantities are formed cosmogenically by the reaction 14
N
 +
n
 → 14
C
 + 1
H
. The most stable artificial radioisotope is 11
C
, which has a half-life of 20.3402(53) min. All other radioisotopes have half-lives under 20 seconds, most less than 200 milliseconds. The least stable isotope is 8
C
, with a half-life of 3.5(1.4)×10−21 s. Light isotopes tend to decay into isotopes of boron and heavy ones tend to decay into isotopes of nitrogen.

Paleoceanography is the study of the history of the oceans in the geologic past with regard to circulation, chemistry, biology, geology and patterns of sedimentation and biological productivity. Paleoceanographic studies using environment models and different proxies enable the scientific community to assess the role of the oceanic processes in the global climate by the re-construction of past climate at various intervals. Paleoceanographic research is also intimately tied to paleoclimatology.

The environmental isotopes are a subset of isotopes, both stable and radioactive, which are the object of isotope geochemistry. They are primarily used as tracers to see how things move around within the ocean-atmosphere system, within terrestrial biomes, within the Earth's surface, and between these broad domains.

<span class="mw-page-title-main">Atlantic meridional overturning circulation</span> System of currents in the Atlantic Ocean

The Atlantic meridional overturning circulation (AMOC) is part of a global thermohaline circulation in the oceans and is the zonally integrated component of surface and deep currents in the Atlantic Ocean. It is characterized by a northward flow of warm, salty water in the upper layers of the Atlantic, and a southward flow of colder, deep waters. These "limbs" are linked by regions of overturning in the Nordic and Labrador Seas and the Southern Ocean, although the extent of overturning in the Labrador Sea is disputed. The AMOC is an important component of the Earth's climate system, and is a result of both atmospheric and thermohaline drivers.

<span class="mw-page-title-main">Ocean temperature</span> Physical quantity that expresses hot and cold in ocean water

The ocean temperature varies by depth, geographical location and season. Both the temperature and salinity of ocean water differs. Warm surface water is generally saltier than the cooler deep or polar waters; in polar regions, the upper layers of ocean water are cold and fresh. Deep ocean water is cold, salty water found deep below the surface of Earth's oceans. This water has a very uniform temperature, around 0-3 °C. The ocean temperature also depends on the amount of solar radiation falling on its surface. In the tropics, with the Sun nearly overhead, the temperature of the surface layers can rise to over 30 °C (86 °F) while near the poles the temperature in equilibrium with the sea ice is about −2 °C (28 °F). There is a continuous circulation of water in the oceans. Thermohaline circulation (THC) is a part of the large-scale ocean circulation that is driven by global density gradients created by surface heat and freshwater fluxes. Warm surface currents cool as they move away from the tropics, and the water becomes denser and sinks. The cold water moves back towards the equator as a deep sea current, driven by changes in the temperature and density of the water, before eventually welling up again towards the surface.

Harry Leonard Bryden, FRS is an American physical oceanographer, professor at University of Southampton, and staff at the National Oceanography Centre, Southampton. He is best known for his work in ocean circulation and in the role of the ocean in the Earth's climate.

<span class="mw-page-title-main">Oceanic carbon cycle</span> Ocean/atmosphere carbon exchange process

The oceanic carbon cycle is composed of processes that exchange carbon between various pools within the ocean as well as between the atmosphere, Earth interior, and the seafloor. The carbon cycle is a result of many interacting forces across multiple time and space scales that circulates carbon around the planet, ensuring that carbon is available globally. The Oceanic carbon cycle is a central process to the global carbon cycle and contains both inorganic carbon and organic carbon. Part of the marine carbon cycle transforms carbon between non-living and living matter.

Adina Paytan is a research professor at the Institute of Marine Sciences at the University of California, Santa Cruz. known for research into biogeochemical cycling in the present and the past. She has over 270 scientific publications in journals such as Science, Nature, Proceedings of the National Academy of Sciences, and Geophysical Research Letters.

<span class="mw-page-title-main">Shannon Valley</span> American climate scientist

Shannon Gabrielle Valley is an American climate scientist and policy advisor. She is based at Georgia Tech, where she studies the climate history of planet Earth. She worked as a liaison between the White House and NASA Headquarters for the Obama administration. In 2020 Valley was appointed to Joe Biden's NASA transition team.

The Atlantic meridional overturning circulation (AMOC) is a large system of ocean currents, like a conveyor belt. It is driven by differences in temperature and salt content and it is an important component of the climate system. However, the AMOC is not a static feature of global circulation. It is sensitive to changes in temperature, salinity and atmospheric forcings. Climate reconstructions from δ18O proxies from Greenland reveal an abrupt transition in global temperature about every 1470 years. These changes may be due to changes in ocean circulation, which suggests that there are two equilibria possible in the AMOC. Stommel made a two-box model in 1961 which showed two different states of the AMOC are possible on a single hemisphere. Stommel’s result with an ocean box model has initiated studies using three dimensional ocean circulation models, confirming the existence of multiple equilibria in the AMOC.

Bette Otto-Bliesner is an earth scientist known for her modeling of Earth's past climate and its changes over different geological eras.

Ana Ravelo is a paleoceanographer known for her research on tropical oceans. She is a professor at the University of California Santa Cruz and was elected a fellow of the American Geophysical Union in 2012.

Sidney Hemming is an analytical geochemist known for her work documenting Earth's history through analysis of sediments and sedimentary rocks. She is a professor of earth and environmental sciences at Columbia University.

Delia Wanda Oppo is an American scientist who works on paleoceanography where she focuses on past variations in water circulation and the subsequent impact on Earth's climate system. She was elected a fellow of the American Geophysical Union in 2014.

Lisa M. Beal is a professor at the University of Miami known for her work on the Agulhas Current. She is the editor-in-chief of the Journal of Geophysical Research: Oceans.

The Agulhas Leakage is an inflow of anomalously warm and saline water from the Indian Ocean into the South Atlantic due to the limited latitudinal extent of the African continent compared to the southern extension of the subtropical super gyre in the Indian Ocean. The process occurs during the retroflection of the Agulhas Current via shedding of anticyclonic Agulhas Rings, cyclonic eddies and direct inflow. The leakage contributes to the Atlantic Meridional Overturning Circulation (AMOC) by supplying its upper limb, which has direct climate implications.

Laurie Menviel or L. Menviel; Laurie Menviel is a palaeoclimatologist, and a Scientia fellow, at the University of New South Wales, who was awarded a Dorothy Hill Medal in 2019.

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References

  1. ↑ Delaney, Peggy; Abrantes, Fatima; Alexander, Vera; Alldredge, Alice L.; Almogi-Labin, Ahuva; Alonso, Belén; Anand, Pallavi; Ates, Sibel Bargu; Bauch, Dorothea; Bell, Robin E.; Benitez-Nelson, Claudia (2005). "Autobiographical Sketches of Women in Oceanography". Oceanography. 18 (1): 65–246. ISSN   1042-8275. JSTOR   43925658.
  2. ↑ "Jean Lynch-Stieglitz". jls.eas.gatech.edu. Retrieved 23 July 2021.
  3. 1 2 "Lynch-Stieglitz CV" (PDF).
  4. ↑ "Elsevier Enhanced Reader". reader.elsevier.com. 337–338: 1. 2012.
  5. 1 2 "Six Faculty Named 2015 AAAS Fellows". news.gatech.edu. Retrieved 2021-07-25.
  6. ↑ Lynch-Stieglitz, Jean; Stocker, Thomas F.; Broecker, Wallace S.; Fairbanks, Richard G. (1995). "The influence of air-sea exchange on the isotopic composition of oceanic carbon: Observations and modeling". Global Biogeochemical Cycles. 9 (4): 653–665. Bibcode:1995GBioC...9..653L. doi:10.1029/95GB02574. ISSN   1944-9224. S2CID   129194624.
  7. ↑ Lynch-Stieglitz, Jean; Fairbanks, Richard G. (May 1994). "A conservative tracer for glacial ocean circulation from carbon isotope and palaeo-nutrient measurements in benthic foraminifera". Nature. 369 (6478): 308–310. Bibcode:1994Natur.369..308L. doi:10.1038/369308a0. ISSN   1476-4687. S2CID   4238180.
  8. ↑ Lynch-Stieglitz, Jean; Fairbanks, Richard G.; Charles, Christopher D. (1994). "Glacial-interglacial history of Antarctic Intermediate Water: Relative strengths of Antarctic versus Indian Ocean sources". Paleoceanography. 9 (1): 7–29. Bibcode:1994PalOc...9....7L. doi:10.1029/93PA02446. ISSN   1944-9186.
  9. ↑ Lund, David C.; Lynch-Stieglitz, Jean; Curry, William B. (November 2006). "Gulf Stream density structure and transport during the past millennium". Nature. 444 (7119): 601–604. Bibcode:2006Natur.444..601L. doi:10.1038/nature05277. ISSN   1476-4687. PMID   17136090. S2CID   4431695.
  10. ↑ Lynch-Stieglitz, Jean (2017-01-03). "The Atlantic Meridional Overturning Circulation and Abrupt Climate Change". Annual Review of Marine Science. 9 (1): 83–104. Bibcode:2017ARMS....9...83L. doi:10.1146/annurev-marine-010816-060415. ISSN   1941-1405. PMID   27814029.
  11. ↑ Liu, Z.; Otto-Bliesner, B. L.; He, F.; Brady, E. C.; Tomas, R.; Clark, P. U.; Carlson, A. E.; Lynch-Stieglitz, J.; Curry, W.; Brook, E.; Erickson, D. (2009-07-17). "Transient Simulation of Last Deglaciation with a New Mechanism for Bolling-Allerod Warming". Science. 325 (5938): 310–314. Bibcode:2009Sci...325..310L. doi:10.1126/science.1171041. ISSN   0036-8075. PMID   19608916. S2CID   16383717.
  12. ↑ Lynch-Stieglitz, J.; Adkins, J. F.; Curry, W. B.; Dokken, T.; Hall, I. R.; Herguera, J. C.; Hirschi, J. J.-M.; Ivanova, E. V.; Kissel, C.; Marchal, O.; Marchitto, T. M.; McCave, I. N.; McManus, J. F.; Mulitza, S.; Ninnemann, U.; Peeters, F.; Yu, E.-F.; Zahn, R. (6 April 2007). "Atlantic Meridional Overturning Circulation During the Last Glacial Maximum". Science. 316 (5821): 66–69. Bibcode:2007Sci...316...66L. doi:10.1126/science.1137127. ISSN   0036-8075. PMID   17412948. S2CID   44803349.
  13. ↑ Purcell, Conor (2017-06-19). "Thin ice: Vanishing ice only exacerbates a bad, climate change-fueled situation". Ars Technica. Retrieved 2021-07-25.
  14. ↑ Koutavas, A. (12 July 2002). "El Nino-Like Pattern in Ice Age Tropical Pacific Sea Surface Temperature". Science. 297 (5579): 226–230. Bibcode:2002Sci...297..226K. doi:10.1126/science.1072376. PMID   12114619. S2CID   32854413.
  15. ↑ "Jean Lynch-Stieglitz". www.nasonline.org. Retrieved 2021-07-25.
  16. ↑ "Historic Fellows | American Association for the Advancement of Science". www.aaas.org. Retrieved 2021-07-25.
  17. ↑ "Cesare Emiliani Lecture | AGU". www.agu.org. Retrieved 2021-07-25.
  18. ↑ "2019 Class of AGU Fellows Announced". Eos. Retrieved 2021-07-25.
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