Special Seminar: Dr. Samantha Bova
Special seminar: 2022 Ocean Discovery Lecturer
ITS GETTING HOT IN HERE: REINTERPRETED CLIMATE PROXIES ALTER UNDERSTANDING OF INTERGLACIAL WARMTH
Dr. Samantha Bova
San Diego State University
March 30, 2022, 3:30pm
Hosted by Chesapeake Biological Lab,
University of Maryland Center for Environmental Science
Remote zoom login:
https://umces-edu.zoom.us/j/97903285754?pwd=S2lIbDFERHpzeEpJdGRUV0RyZmZCQT09
Meeting ID: 979 0328 5754
Passcode: 1925
(More login info at end of document)
Abstract: Predicting the response of Earth’s climate system to rising global temperatures is one of the grand challenges facing the scientific community today. Scientific ocean drilling has been at the forefront of this challenge for decades enabling the collection of sedimentary archives that offer a perspective on Earth’s climate during previous interglacials unaffected by human activities. Paleoclimate records, such as these, are the only way to observe the response of Earth’s climate system to warmer than present temperatures. The Holocene and last interglacial thermal maxima, occurring approximately 10 to 6 and 128 to 123 thousand years ago, respectively, are the two most recent warm intervals in the geologic record and are often used as analogs of future climate. This is because proxy reconstructions, arguably interpreted to record global mean temperatures, indicate these periods were as warm or warmer than recent decades. However, early interglacial warmth is not simulated in the annual mean by state-of-the-art climate models. This model-data inconsistency thereby limits our understanding of both the cause and climate system response of the observed warmth, and thus the utility of these time intervals to help predict our future. Using sediments collected off the north coast of Papua New Guinea on IODP Expedition 363 and a suite of sediment cores recovered on previous ocean coring expeditions, I will demonstrate that early interglacial warmth, as recorded by proxies, is a seasonal feature driven by changes in incoming northern hemisphere summer solar radiation, and that peak mean annual global temperature actually occurs thousands of years later. This result confirms climate model simulations that show global mean annual temperature warming, rather than cooling, across past interglacial periods, and thus resolves the long-standing interglacial temperature conundrum. The new results show that Earth’s global temperatures have reached uncharted territory that has not been observed over the past 12,000 and perhaps 128,000 years.
Lecturer Bio: Dr. Samantha Bova is a marine geologist and paleoceanographer specializing in the reconstruction of past changes in Earth’s climate using marine sediment and geochemistry. Her areas of interest include the evolution and drivers of past warm periods in Earth history, abrupt climate change, natural climate variability, and controls on tropical rainfall. Her current research investigates the history of global temperature during the past two warm intervals in Earth history, suggesting that modern global temperatures exceed those observed over at least the past 125,000 years. Bova is also actively engaged in the recovery of sediment from the seafloor, having led a month-long ocean expedition to collect sediment from offshore Chile in 2019 that will be utilized to reconstruct oceanographic conditions in the southeast Pacific and the history of the Patagonia icefields. Bova received a Ph.D. in Earth, Environmental and Planetary Science as well as an M.S. in Geological Sciences from Brown University and an A.B. in Earth and Planetary Science from Washington University in St. Louis. Bova started as an Assistant Professor at San Diego State University this fall.
