Lorraine Lisiecki

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Lorraine Lisiecki is an American paleoclimatologist. She is a professor in the Department of Earth Sciences at the University of California, Santa Barbara. [1] She has proposed a new analysis of the 100,000-year problem in the Milankovitch theory of climate change. [2] She also created the analytical software behind the LR04, [3] a "standard representation of the climate history of the last five million years". [4]

Contents

Education

Lisiecki graduated in 1995 from the South Carolina Governor’s School for Science and Mathematics. [5] [6] Lisiecki received her B.Sc. in Earth, Atmospheric, and Planetary Science in 1999 and also obtained an M.Sc. in Geosystems in 2000 from the Massachusetts Institute of Technology. She earned a M.Sc. and Ph.D. in Geological Sciences, both from Brown University in 2003 and 2005. Lisiecki's Ph.D. thesis was titled “Paleoclimate time series: New alignment and compositing techniques, a 5.3-Myr benthic δ18O stack, and analysis of Pliocene-Pleistocene climate transitions”. [7]

Current research

Lisiecki's current research focuses on paleoclimatology. Lisiecki's research interest in paleoclimatology arose from the lack of research and current understanding of the glacial cycles. Lisiecki uses various computational and mathematical methods to interpret and compare different paleoclimate records. [5] In specific, she focuses on the evolution of the Plio-Pleistocene climate due to its relation to the Milankovitch forcing, 100-kyr glacial cycles, the carbon cycle, and deep-ocean circulation. Currently, Lisiecki designs and develops software for rendering age models and stratigraphy. [7] [8] As well, Lisiecki is creating 3D models of ocean circulation to determine the relationship between orbital forcing and ocean circulation patterns and account for time-variant uncertainties. [9]

Contributions

HMM-Match (Lin et al, 2014)

Software designed using a Hidden Markov Model (HMM) for probabilistic sequence alignment of stratigraphic records. [10] [11]

Match & Autocomp Software (Lisiecki and Lisiecki, 2002)

Paleoceanography software designed to find the optimal alignment of two paleoclimate signals using penalty functions to constrain the rate of accumulation for sediments. [12]

LR04 Benthic Stack (Lisiecki and Raymo, 2005)

A Pliocene-Pleistocene stack, spanning 5.3-Myr, demonstrating an average of 57 globally distributed Benthic δ18O records collected from scientific literature, which measure ice volume and deep ocean temperature. The records were placed on a common age model, represented by a graphic correlation algorithm. [13] Lisiecki and Raymo's LR04 Stack contains significantly more variance in benthic δ18O, in comparison to former published stacks of the late Pleistocene epoch. In the LR04, there are higher resolution records, an improved alignment technique, and a higher percentage of records from the Atlantic. [14]

The LR04 Stack is one of the most heavily cited Pliocene-entitled papers for δ18O due to the intensive mathematical meticulousness incorporated into the record, the level of objectivity involved, its use of global distribution and duration. The existence of the LR04 Stack serves as a very important tool in paleoceanography. [5]

Earth's climate history

In an effort to find patterns in Earth's climate history, Lisiecki researches ocean sediment cores. [15] The history of Earth's climate lies in the composition of ocean sediments as scientists are able to derive millions of years worth of information through the alignment of these sedimentary layers. [16] Through these layers, Lisiecki found a connection between earth’s climate cycle and earth’s orbital cycle; assuming glaciation and orbital eccentricity are both on 100,000-year cycles, she found that stronger changes in Earth’s orbit correlated with weaker changes in glaciation. [15] The correlation between the two consists of complicated relations as 3 different elements of Earth's orbit; eccentricity, tilt and precession, must be taken into consideration alongside Earth's convoluted climate system. [15]

100,000-year problem

One previous hypothesis held that the 100,000-year glacial cycles in the past 800,000 years were a result of cyclic changes in the Earth's orbital eccentricity. In 2010, Lisiecki discovered a negative correlation between the strength of glacial cycles and the eccentricity of the Earth’s orbit over the past 1.2 million years, suggesting the possibility of internal instability of the Earth’s climate in conjunction with its orbital cycles. [15] Lisiecki proposed that this negative correlation is caused by the inhibition of internal climate feedbacks by periods of strong precession forcing. Lisiecki also suggested that long-term internal factors might be responsible, such as the carbon cycle or the ice sheets, though more research is required. [17]

Awards

Related Research Articles

The Wolstonian Stage is a middle Pleistocene stage of the geological history of Earth from approximately 374,000 until 130,000 years ago. It precedes the Eemian Stage in Europe and follows the Hoxnian Stage in the British Isles.

The geologic temperature record are changes in Earth's environment as determined from geologic evidence on multi-million to billion (109) year time scales. The study of past temperatures provides an important paleoenvironmental insight because it is a component of the climate and oceanography of the time.

The Illinoian Stage is the name used by Quaternary geologists in North America to designate the period c.191,000 to c.130,000 years ago, during the Chibanian stage of the Pleistocene, when sediments comprising the Illinoian Glacial Lobe were deposited. It precedes the Sangamonian Stage and follows the Pre-Illinoian Stage in North America. The Illinoian Stage is defined as the period of geologic time during which the glacial tills and outwash, which comprise the bulk of the Glasford Formation, accumulated to create the Illinoian Glacial Lobe. It occurs at about the same time as the penultimate glacial period.

<span class="mw-page-title-main">Elster glaciation</span>

The Elster glaciation or, less commonly, the Elsterian glaciation, in the older and popular scientific literature also called the Elster Ice Age (Elster-Eiszeit), is the oldest known ice age that resulted in the large-scale glaciation of North Germany. It took place 500,000–300,000 years ago. It succeeded a long period of rather warmer average temperatures, the Cromerian Complex. The Elster was followed by the Holstein interglacial and the Saale glaciation. The glacial period is named after the White Elster, a right tributary of the Saale.

<span class="mw-page-title-main">Mindel glaciation</span>

The Mindel glaciation is the third youngest glacial stage in the Alps. Its name was coined by Albrecht Penck and Eduard Brückner, who named it after the Swabian river, the Mindel. The Mindel glacial occurred in the Middle Pleistocene; it was preceded by the Haslach-Mindel interglacial and succeeded by the Mindel-Riss interglacial.

The Beestonian Stage is an early Pleistocene stage in the geological history of the British Isles. It is named after Beeston Cliffs near West Runton in Norfolk where deposits from this stage are preserved.

The Pastonian interglacial, now called the Pastonian Stage, is the name for an early or middle Pleistocene stage of geological history in the British Isles. It precedes the Beestonian Stage and follows the Pre-Pastonian Stage. Unfortunately the precise age of this stage cannot yet be defined in terms of absolute dating or MIS stages. The Pre-Pastonian Stage is equivalent to the Tiglian C5-6 Stage of Europe and the Pre-Illinoian I glaciation of the early Pre-Illinoian Stage of North America.

The Bramertonian Stage is the name for an early Pleistocene biostratigraphic stage of geological history the British Isles. It precedes the Pre-Pastonian Stage. It derives its name from Bramerton Pits in Norfolk, where the deposits can be found on the surface. The exact timing of the beginning and end of the Bramertonian Stage is currently unknown. It is only known that it is equivalent to the Tiglian C1-4b Stage of Europe and early Pre-Illinoian Stage of North America. It lies somewhere in time between Marine Oxygen Isotope stages 65 to 95 and somewhere between 1.816 and 2.427 Ma. The Bramertonian is correlated with the Antian stage identified from pollen assemblages in the Ludham borehole.

<span class="mw-page-title-main">Marine isotope stages</span> Alternating warm and cool periods in the Earths paleoclimate, deduced from oxygen isotope data

Marine isotope stages (MIS), marine oxygen-isotope stages, or oxygen isotope stages (OIS), are alternating warm and cool periods in the Earth's paleoclimate, deduced from oxygen isotope data derived from deep sea core samples. Working backwards from the present, which is MIS 1 in the scale, stages with even numbers have high levels of oxygen-18 and represent cold glacial periods, while the odd-numbered stages are lows in the oxygen-18 figures, representing warm interglacial intervals. The data are derived from pollen and foraminifera (plankton) remains in drilled marine sediment cores, sapropels, and other data that reflect historic climate; these are called proxies.

The Plio-Pleistocene is an informally described geological pseudo-period, which begins about 5 million years ago (Mya) and, drawing forward, combines the time ranges of the formally defined Pliocene and Pleistocene epochs—marking from about 5 Mya to about 12 kya. Nominally, the Holocene epoch—the last 12 thousand years—would be excluded, but most Earth scientists would probably treat the current times as incorporated into the term "Plio-Pleistocene"; see below.

<span class="mw-page-title-main">Quaternary glaciation</span> Series of alternating glacial and interglacial periods

The Quaternary glaciation, also known as the Pleistocene glaciation, is an alternating series of glacial and interglacial periods during the Quaternary period that began 2.58 Ma and is ongoing. Although geologists describe this entire period up to the present as an "ice age", in popular culture this term usually refers to the most recent glacial period, or to the Pleistocene epoch in general. Since Earth still has polar ice sheets, geologists consider the Quaternary glaciation to be ongoing, though currently in an interglacial period.

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.

In geochemistry, paleoclimatology and paleoceanography δ18O or delta-O-18 is a measure of the ratio of stable isotopes oxygen-18 (18O) and oxygen-16 (16O). It is commonly used as a measure of the temperature of precipitation, as a measure of groundwater/mineral interactions, and as an indicator of processes that show isotopic fractionation, like methanogenesis. In paleosciences, 18O:16O data from corals, foraminifera and ice cores are used as a proxy for temperature.

<span class="mw-page-title-main">100,000-year problem</span> Discrepancy between past temperatures and the amount of incoming solar radiation

The 100,000-year problem of the Milankovitch theory of orbital forcing refers to a discrepancy between the reconstructed geologic temperature record and the reconstructed amount of incoming solar radiation, or insolation over the past 800,000 years. Due to variations in the Earth's orbit, the amount of insolation varies with periods of around 21,000, 40,000, 100,000, and 400,000 years. Variations in the amount of incident solar energy drive changes in the climate of the Earth, and are recognised as a key factor in the timing of initiation and termination of glaciations.

<span class="mw-page-title-main">Marine Isotope Stage 11</span> Marine isotope stage between 424,000 and 374,000 years ago

Marine Isotope Stage 11 or MIS 11 is a Marine Isotope Stage in the geologic temperature record, covering the interglacial period between 424,000 and 374,000 years ago. It corresponds to the Hoxnian Stage in Britain.

Paleoceanography and Paleoclimatology is a peer-reviewed scientific journal published by the American Geophysical Union. It publishes original research articles dealing with all aspects of understanding and reconstructing Earth's past climate and environments from the Precambrian to modern analogs. Until the first of January 2018 the name of the journal was Paleoceanography.

<span class="mw-page-title-main">Maureen Raymo</span> American paleoclimatologist and marine geologist

Maureen E. "Mo" Raymo is an American paleoclimatologist and marine geologist. She is the Co-Founding Dean of the Columbia Climate School, Director of the Lamont–Doherty Earth Observatory of Columbia University, the G. Unger Vetlesen Professor of Earth & Environmental Sciences, and Director of the Lamont–Doherty Core Repository at the Lamont–Doherty Earth Observatory of Columbia University. She is the first female climate scientist and first female scientist to head the institution.

<span class="mw-page-title-main">Marine Isotope Stage 9</span>

Marine Isotope Stage 9 was an interglacial period that consisted of two interstadial and one stadial period. It is the final period of the Lower Paleolithic and lasted from 337,000 to 300,000 years ago according to Lisiecki and Raymo's LR04 Benthic Stack. It corresponds to the Purfleet Interglacial in Britain, the Holstein Interglacial in continental Europe, and the Pre-Illinoian in North America.

<span class="mw-page-title-main">Don Glaciation</span> Major glaciation of eastern Europe

The Don Glaciation, also known as the Donian Glaciation and the Donian Stage, was the major glaciation of the East European Plain, 0.5–0.8 million years ago, during the Cromerian Stage of the Middle Pleistocene. It is correlated to Marine Isotope Stage 16, approximately 650,000 years ago, which globally contained one of the largest glacial volumes of the Quaternary.

References

  1. ↑ USCB faculty page
  2. ↑ Lorraine E. Lisiecki (2010). "Links between eccentricity forcing and the 100,000-year glacial cycle". Nature Geoscience. 3 (5): 349–352. Bibcode:2010NatGe...3..349L. doi:10.1038/ngeo828. S2CID   19077579.
  3. ↑ Paleoceangraphy, 2004 Archived 2011-06-16 at the Wayback Machine
  4. 1 2 Geological Society of America, 2008 Subaru Outstanding Woman in Science Award
  5. 1 2 3 "Into the deep ocean with Lorraine Lisiecki". Forecast: a podcast about climate science and climate scientists. 2016-02-12. Retrieved 2016-11-03.
  6. ↑ "About". SC Governor's School for Science & Mathematics. 2012-09-18. Retrieved 2016-11-03.
  7. 1 2 "Lorraine Lisiecki's CV" (PDF).
  8. 1 2 3 "Lorraine Lisiecki". lorraine-lisiecki.com. Retrieved 2016-10-29.
  9. ↑ "Into the deep ocean with Lorraine Lisiecki - Forecast". l.facebook.com. Retrieved 2016-11-01.
  10. ↑ "Bayesian Geociences". ccmbweb.ccv.brown.edu. Retrieved 2016-11-01.
  11. ↑ Lin Luan, Khider Deborah, Lisiecki Lorraine E., Lawrence Charles E. (2014). "Probabilistic sequence alignment of stratigraphic records" (PDF). Paleoceanography. 29 (10): 976–989. Bibcode:2014PalOc..29..976L. doi: 10.1002/2014pa002713 .{{cite journal}}: CS1 maint: multiple names: authors list (link)
  12. ↑ "Match Software". lorraine-lisiecki.com. Retrieved 2016-11-01.
  13. ↑ "LR04 Benthic Stack". www.lorraine-lisiecki.com. Retrieved 2016-11-03.
  14. ↑ "LR04 Global Pliocene-Pleistocene Benthic d180 Stack".
  15. 1 2 3 4 "UCSB geologist discovers pattern in Earth's long-term climate record". EurekAlert. AAAS. Retrieved October 29, 2016.
  16. ↑ "Paleoceanography" (PDF). lorraine-lisiecki.com. American Geophysical Union. 2014. Retrieved November 4, 2016.
  17. ↑ Lisiecki, Lorraine E. (2010). "Links between eccentricity forcing and the 100,000-year glacial cycle". Nature Geoscience. 3 (5): 349–352. Bibcode:2010NatGe...3..349L. doi:10.1038/ngeo828. S2CID   19077579.
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