Julie Richey, Ph.D.
Biography
Paleoclimate and Environmental Change
Establishing a baseline of natural climate variability over the past 2,000 years is essential to accurately predicting regional responses to anthropogenic climate change. My research focus is reconstructing temperature and hydroclimatic variability in the Gulf of Mexico/Subtropical Atlantic Ocean using a broad range of different paleoclimate archives. In addition to generating proxy-based paleoclimate records, I am working on proxy development and calibration studies to improve our ability to quantify past changes in temperature, salinity and precipitation in both terrestrial and marine environments.
Coral Paleoclimate
Research Interests
- Using stable isotopes and trace elements to reconstruct climate from coral skeletons
- Investigating the effect of water quality and coral ecology on geochemical proxies
Field Sites
- US Virgin Islands
- Dry Tortugas National Park
- Florida Keys Reef Tract
Project web page: https://www.usgs.gov/centers/spcmsc/science/coral-reef-ecosystem-studies-crest
Holocene Paleoclimate in the Gulf of Mexico
Project web page: https://www.usgs.gov/centers/spcmsc/science/climate-and-environmental-change-gulf-mexico-and-caribbean
Research Interests
- Paleoclimate Reconstruction from Marine and Lake Sediments
- Coral Reefs as Climate Archives
- Paleoceanographic Proxy Calibration
Field Sites
- Garrison Basin (Gulf of Mexico)
- Fisk Basin (Gulf of Mexico)
- Pigmy Basin (Gulf of Mexico)
- Sediment Trap Site (Gulf of Mexico)
Education
- Ph. D. - Marine Geology (2010), Univ. of South Florida, College of Marine Science
- M.S. - Marine Geology (2007), Univ. of South Florida, College of Marine Science
- B.S. - Geological Sciences/Biological Sciences (2004), The Ohio State Univ.
Google Scholar Profile: https://scholar.google.com/citations?user=595LDgUAAAAJ&hl=en&oi=ao
Science and Products
Reconstructing Ocean Circulation & Hydroclimate in the Subtropical Atlantic
Changes in rainfall patterns as a result of anthropogenic climate change are already having large ecological and socioeconomic impacts across the globe. Increases in flood damage, wildfire damage, and agricultural losses can all be attributed to anomalous rainfall events and prolonged droughts across the United States in recent years. Additionally, Atlantic Ocean circulation, which has a large...
Coral Reef Ecosystem Studies (CREST)
The specific objectives of this project are to identify and describe the processes that are important in determining rates of coral-reef construction. How quickly the skeletons of calcifying organisms accumulate to form massive barrier-reef structure is determined by processes of both construction (how fast organisms grow and reproduce) and destruction (how fast reefs break down by mechanical...
Reef History and Climate Change
Ecosystem-wide study of seafloor erosion, changing coastal water depths, and effects on coastal storm and wave impacts along the Florida Keys Coral Reef Tract in South Florida.
Paleoclimate Reconstruction from Marine and Lake Sediments
Instrumental measurements of climate variables (e.g., precipitation, temperature, ocean circulation, etc.) are only available over the past century or less. In order to quantify the rate and magnitude of natural climate variability going back in time beyond the 20th century, scientists rely on paleoclimate reconstructions.
Paleoceanographic Proxy Calibration
A sediment trap time series in the northern Gulf of Mexico is used to better assess the control of environmental variables (e.g., temperature and salinity) on the flux of both microfossils and molecular fossils to the sediments. The information gained from sediment trap studies is used to develop better proxy-based estimates of past oceanographic conditions from analyses of microfossils and ...
Climate and Environmental Change in the Gulf of Mexico and Caribbean
This project documents paleoceanographic, climatic, and environmental changes in the Gulf of Mexico and adjacent land areas over the last 10,000 years. The paleoenvironmental data is used to determine rates of change in the past, and to better understand both the natural and anthropogenic factors that contribute to climate variability on inter-annual to millennial timescales.
PaCTS 1.0: A crowdsourced reporting standard for paleoclimate data
The progress of science is tied to the standardization of measurements, instruments, and data. This is especially true in the Big Data age, where analyzing large data volumes critically hinges on that data being standardized. Accordingly, the lack of community-sanctioned data standards in paleoclimatology has largely precluded the benefits of Big...
Kehrwald, Natalie M.; Khider, Deborah; Emile-Geay, Julien; McKay, Nicholas P.; Gili, Yolanda; Garijo, Daniel; Ratnakar, Varun; Brewer, Peter; Csank, Adam; Dassie, Emilie; Delong, Kristine; Felix, Thomas; Gray, William; Jonkers, Lucas; Kahle, Michael; Kaufman, Darrell S.; Richey, Julie N.; Schmittner, Andreas; Sutherland, Elaine Kennedy; Alonso-Garcia, Montserrat; Sebastian, Bertrand; Bothe, Oliver; Bunn, Andrew; Chevalier, Manuel; Francus, Pierre; Frappier, Amy; Goring, Simon; Martrat, Belen; McGregor, Helen V.; Allen, Kathryn J.; Arnaud, Fabien; Axford, Yarrow L.; Barrows, Timothy T.; Bazin, Lucie; Pilaar Birch, S.E.; Bradley, Elizabeth; Bregy, Joshua; Capron, Emilie; Cartapanis, Olivier; Chiang, Hong-Wei; Cobb, Kim; Debret, Maxime; Dommain, Rene; Du, Jianghui; Dyez, Kelsey; Emerick, Suellyn; Erb, Michael; Falster, Georgina; Finsinger, Walter; Fortier, Daniel; Gauthier, Nicolas; George, Steven; Grimm, Eric; Hertzberg, Jennifer; Hibbert, Fiona; Hillman, Aubrey; Hobbs, William; Huber, Matthew; Hughes, Anna L. C.; Jaccard, Samuel; Jiaoyang, Ruan; Kienast, Markus; Konecky, Bronwen; Le Roux, Gael; Lyubchich, Vyacheslav; Novello, Valdir; Olaka, Lydia; Partin, Judson W.; Pearce, Christof; Phipps, Steven J.; Pignol, Cecile; Pietrowska, Natalia; Poli, Maria-Serena; Prokopenko, Alexander; Schwanck, Franciele; Stepanek, Christian; Swann, George E. A.; Telford, Richard; Thomas, Elizabeth R.; Thomas, Zoe; Truebe, Sarah; von Gunten, Lucien; Waite, Amanda; Weitzel, Nils; Wilhelm, Bruno; Williams, John B.; Winstrup, Mai; Zhao, Ning; Zhou, YuxinConsiderations for Globigerinoides ruber (white and pink) paleoceanography: Comprehensive insights from a long‐running sediment trap
We present a detailed analysis of the seasonal distribution, size, morphological variability and geochemistry of co‐occurring pink and white chromotypes of Globigerinoides ruberfrom a high‐resolution (1–2 weeks) and long‐running sediment trap time series in the northern Gulf of Mexico. We find no difference in the seasonal flux of the two...
Richey, Julie N.; Thirumalai, Kaustubh; Khider, Deborah; Reynolds, Caitlin E.; Partin, Judson W.; Quinn, Terrence M.Reconstructing precipitation in the tropical South Pacific from dinosterol 2H/1H ratios in lake sediment
The South Pacific Convergence Zone (SPCZ) is the Southern Hemisphere’s largest precipitation feature supplying freshwater to 11 million people. Despite its significance, little is known about the location and intensity of SPCZ precipitation prior to instrumental records, hindering attempts to predict precipitation changes in a warming world. Here...
Maloney, Ashley E.; Nelson, Daniel B.; Richey, Julie N.; Prebble, Matthew; Sear, David A.; Hassall, Jonathan D.; Langdon, Peter G.; Croudace, Ian W.; Zawadzki, Atun; Sachs, Julian P.Quantifying uncertainty in Sr/Ca-based estimates of SST from the coral Orbicella faveolata
The strontium to calcium ratio (Sr/Ca) in aragonitic skeletons of massive corals provides a proxy for sea surface temperature (SST) that can be used to reconstruct paleoclimates across decades, centuries, and, potentially, millennia. Determining the reproducibility of Sr/Ca records among contemporaneous coral colonies from the same region is...
Flannery, Jennifer A.; Richey, Julie N.; Toth, Lauren T.; Kuffner, Ilsa B.; Poore, Richard Z.Environmental controls on the geochemistry of Globorotalia truncatulinoides in the Gulf of Mexico: Implications for paleoceanographic reconstructions
Modern observations of planktic foraminifera from sediment trap studies help to constrain the regional ecology of paleoceanographically valuable species. Results from a weekly-resolved sediment trap time series (2008–2014) in the northern Gulf of Mexico demonstrate that 92% of Globorotalia truncatulinoides ...
Reynolds, Caitlin E.; Richey, Julie N.; Fehrenbacher, Jennifer S.; Rosenheim, Brad E.; Spero, Howard J.A North American Hydroclimate Synthesis (NAHS) of the Common Era
This study presents a synthesis of century-scale hydroclimate variations in North America for the Common Era (last 2000 years) using new age models of previously published multiple proxy-based paleoclimate data. This North American Hydroclimate Synthesis (NAHS) examines regional hydroclimate patterns and related environmental indicators,...
Rodysill, Jessica R. ; Anderson, Lesleigh; Cronin, Thomas M.; Jones, Miriam C.; Thompson, Robert S.; Wahl, David B.; Willard, Debra A.; Addison, Jason A.; Alder, Jay R.; Anderson, Katherine H.; Anderson, Lysanna; Barron, John A.; Bernhardt, Christopher E.; Hostetler, Steven W.; Kehrwald, Natalie M.; Khan, Nicole; Richey, Julie N.; Starratt, Scott W.; Strickland, Laura E.; Toomey, Michael; Treat, Claire C.; Wingard, G. LynnPronounced centennial-scale Atlantic Ocean climate variability correlated with Western Hemisphere hydroclimate
Surface-ocean circulation in the northern Atlantic Ocean influences Northern Hemisphere climate. Century-scale circulation variability in the Atlantic Ocean, however, is poorly constrained due to insufficiently-resolved paleoceanographic records. Here we present a replicated reconstruction of sea-surface temperature and salinity from a site...
Thirumalai, Kaustubh; Quinn, Terrence M.; Okumura, Yuko; Richey, Julie N.; Partin, Judson W.; Poore, Richard Z.; Moreno-Chamarro, EduardoMillennial-scale variability in the local radiocarbon reservoir age of south Florida during the Holocene
A growing body of research suggests that the marine environments of south Florida provide a critical link between the tropical and high-latitude Atlantic. Changes in the characteristics of water masses off south Florida may therefore have important implications for our understanding of climatic and oceanographic variability over a broad spatial...
Toth, Lauren T.; Cheng, Hai; Edwards, R. Lawrence; Ashe, Erica; Richey, Julie N.Fidelity of the Sr/Ca proxy in recording ocean temperature in the western Atlantic coral Siderastrea siderea
Massive corals provide a useful archive of environmental variability, but careful testing of geochemical proxies in corals is necessary to validate the relationship between each proxy and environmental parameter throughout the full range of conditions experienced by the recording organisms. Here we use samples from a coral-growth study to test the...
Kuffner, Ilsa B.; Roberts, Kelsey E.; Flannery, Jennifer A.; Morrison, Jennifer M.; Richey, Julie N.Multi-species coral Sr/Ca-based sea-surface temperature reconstruction using Orbicella faveolata and Siderastrea siderea from the Florida Straits
We present new, monthly-resolved Sr/Ca-based sea-surface temperature (SST) records from two species of massive coral, Orbicella faveolata and Siderastrea siderea, from the Dry Tortugas National Park, FL, USA (DTNP). We combine these new records with published data from three additional S. siderea coral colonies to generate a 278-year long multi-...
Flannery, Jennifer A.; Richey, Julie N.; Thirumalai, Kaustubh; Poore, Richard Z.; DeLong, Kristine L.GDGT and alkenone flux in the northern Gulf of Mexico: Implications for the TEX86 and UK137 paleothermometers
The TEX86 and molecular biomarker proxies have been broadly applied in down-core marine sediments to reconstruct past sea surface temperature (SST). Although both TEX86 and have been interpreted as proxies for mean annual SST throughout the global ocean, regional studies of GDGTs and alkenones in sinking particles are required to understand the...
Richey, Julie N.; Tierney, Jessica E.Data for evaluating the Sr/Ca temperature proxy with in-situ temperature in the western Atlantic coral Siderastrea siderea
Massive corals are used as environmental recorders throughout the tropics and subtropics to study environmental variability during time periods preceding ocean-observing instrumentation. However, careful testing of paleoproxies is necessary to validate the environmental-proxy record throughout a range of conditions experienced by the recording...
Kuffner, Ilsa B.; Roberts, Kelsey E.; Flannery, Jennifer A.; Morrison, Jennifer M.; Richey, JuliePre-USGS Publications
Sediment trap in Gulf of Mexico recovered one last time, marking the culmination of a 12-year time series
Julie Richey, Caitlin Reynolds, and colleagues retrieved a sediment trap from the northern Gulf of Mexico during a 3-day cruise (February 7–9, 2020) on board the R/V Pelican. The trap was deployed in 1,200 m of water in 2008 and had been collecting sinking particles from the water column to be used in paleoclimate proxy-calibration studies.
New method to reconstruct winter ocean temperatures of the past
This article is part of the Spring 2019 issue of the Earth Science Matters Newsletter.
USGS Scientists set out to unlock the mysteries of prehistoric droughts in the Caribbean
Scientists spent the last two weeks collecting sediment cores from Lake Enriquillo, a hypersaline lake in the Western Dominican Republic. The sediment cores will help scientists reconstruct the frequency of Caribbean drought and determine the controls on hydroclimate during the Holocene.
USGS scientists publish results from a long-term study of Globigerinoides ruber in the Gulf of Mexico, aiding in reconstruction of past climatic conditions
The planktic foraminifer, Globigerinoides ruber, is the most widely used proxy recorder for reconstructing past temperature and salinity in the low to mid-latitude oceans.
New Study Links Salinity Changes in the Gulf of Mexico to Changes in Rainfall Patterns in the Western Hemisphere
The project is part of a collaborative effort to better understand how sea surface temperature and salinity have varied over the Holocene, or the past 10,000 years. The approach is to measure the magnesium to calcium ratios and oxygen isotopic composition in planktic foraminifera deposited on the seafloor.
Precipitation changes in the western tropical Pacific over the past millennium
This article is part of the Spring 2017 issue of the Earth Science Matters Newsletter.