About

Jud Partin is a Research Associate Professor at the UT Institute for Geophysics. His research interests include paleoclimate, data-model comparisons, and tropical climate. He is involved in understanding Earth's climate history and processes through data analysis and modeling, contributing to the broader field of geophysics with a focus on climate variability and change.

Research topics

• Geology
• Paleontology
• Climatology
• Computer Science
• Meteorology
• Atmospheric sciences
• Environmental science
• Oceanography
• Geography
• Database
• Chemistry
• Mineralogy
• Geochemistry
• Ecology

Selected publications

• Regime Shifts in Holocene Paleohydrology as Recorded by Asian Speleothems

  Paleoceanography and Paleoclimatology · 2025-01-01 · 6 citations

  article

  Abstract Speleothem oxygen isotope records offer unique insights into Asian Monsoon evolution, with their precise chronologies used to identify abrupt climatic events. However, individual records are sometimes used to draw broad conclusions about global climate, without considering the dynamical context in which they exist. We present a robust framework for assessing the regional significance, and hence the potential global significance, of paleoclimate events, using the proposed Meghalayan age onset (associated with the “4.2 ka event”) as a case study. Analyzing 14 well‐dated speleothem oxygen isotope records from the SISAL v3 database and recent literature, we investigate the regional coherency of rapid shifts in Asian paleohydrology, which is the regional center of action for the proposed event, over the Holocene. Three robust methods fail to detect spatially coherent variability consistent with a 4.2 ka event across Asia, either because none exists or because it is of insufficient magnitude. In contrast, the 8.2 ka event is expressed in most records that resolve it. The absence of a clear isotopic excursion across this data set suggests that the “4.2 ka megadrought” was not global, with important implications for archeology and geochronology. This casts doubt on the proposal that the 4.2 ka event marks the onset of a new geologic age. We do, however, observe support for a gradual isotopic enrichment between 3.9 and 3.6 ka, followed by partial recovery—consistent with the “Double Drying” hypothesis and possibly related to changes in El Niño‐Southern Oscillation variability.

  PublisherDOI

• Assessing Matrix and Nonmatrix, Single, and Multipoint Calibration of Trace Elements Using LA‐ICP‐MS on a Tropical Speleothem

  Rapid Communications in Mass Spectrometry · 2025-02-10 · 3 citations

  articleOpen access

  RATIONALE: Suites of trace elements are routinely used in speleothems as proxies to understand periods of past climate change. Laser ablation techniques are regularly implemented to acquire high resolution (50-μm) trace element concentrations in carbonate archives for paleoclimatology. There exists limited research investigating Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) protocols using speleothem samples. This study investigates the difference between using matrix (carbonate) and nonmatrix (silicate) matched reference materials and the utility of 1-point versus multiple point calibration curves. METHODS: Following an extensive review of published literature on speleothem LA-ICP-MS analyses, we conducted two laser ablation experimental runs 8 months apart on a 2.7-cm section of a natural speleothem using matrix and nonmatrix matched reference materials. We used a 193-nm wavelength Analyte G2 laser attached to a X-Series-2 ICP-MS, a silicate reference material, and three carbonate reference materials. Next, we calculated concentrations using a 1-point calibration curve, a 2-point calibration curve, and a 3-point calibration curve. RESULTS: The analysis of matrix and nonmatrix matched reference materials demonstrates that the trends of trace elements/Ca are minimally impacted by the matrix material of the standard. We also show that 2- and 3-point calibration curves bracket the range of sample concentrations compared to a 1-point (silicate) calibration curve. The calculated cave-air temperatures using Mg/Ca concentrations fall within error of each other regardless of the calibration curve approach applied. CONCLUSIONS: Our experiments provide a proof of concept on the conventional setup of standards during LA-ICP-MS speleothem analysis. We suggest the use of at minimum a 2-point (silicate plus carbonate or carbonates) calibration curve that crucially bracket the range of sample concentrations rather than relying on a 1-point silicate standard that does not bracket the sample concentration. Finally, our results have implications for both speleothem studies that use LA-ICP-MS analytical techniques and additional carbonate archives.

  PublisherOA PDFDOI

• Future increase in extreme El Nino supported by past glacial changes

  Nature · 2024-09-25 · 39 citations

  articleOpen access

  El Niño events, the warm phase of the El Niño–Southern Oscillation (ENSO) phenomenon, amplify climate variability throughout the world1. Uncertain climate model predictions limit our ability to assess whether these climatic events could become more extreme under anthropogenic greenhouse warming2. Palaeoclimate records provide estimates of past changes, but it is unclear if they can constrain mechanisms underlying future predictions3–5. Here we uncover a mechanism using numerical simulations that drives consistent changes in response to past and future forcings, allowing model validation against palaeoclimate data. The simulated mechanism is consistent with the dynamics of observed extreme El Niño events, which develop when western Pacific warm pool waters expand rapidly eastwards because of strongly coupled ocean currents and winds6,7. These coupled interactions weaken under glacial conditions because of a deeper mixed layer driven by a stronger Walker circulation. The resulting decrease in ENSO variability and extreme El Niño occurrence is supported by a series of tropical Pacific palaeoceanographic records showing reduced glacial temperature variability within key ENSO-sensitive oceanic regions, including new data from the central equatorial Pacific. The model–data agreement on past variability, together with the consistent mechanism across climatic states, supports the prediction of a shallower mixed layer and weaker Walker circulation driving more frequent extreme El Niño genesis under greenhouse warming. A combination of palaeoclimate proxies and simulations shows that a common mechanism controls El Niño variation in cold and warm states, which supports expectations of more extreme El Niño occurrence in the future.

  PublisherOA PDFDOI

• Fluid Inclusion Microthermometry in Borneo stalagmites: Investigating the role of fabric and open porosity on temperature reconstructions

  2024-03-11

  preprintOpen access

  Fluid inclusion microthermometry has emerged as a powerful tool for reconstructing past land temperatures from speleothems. An implicit assumption of the method is that the closing age of the fluid inclusions is equal to the age of the surrounding calcite, and thus, that the reconstructed temperatures are representative of the cave temperature at which the calcite layers formed. The present study, however, demonstrates that this assumption does not hold true for all stalagmites.Here we show as an example our results obtained from stalagmite SSC01 from Snail Shell Cave (Northern Borneo), that spans the last ~27,000 years, and that was previously investigated for hydroclimate reconstructions (Partin et al., 2007). A temperature record was reconstructed by means of nucleation-assisted microthermometry (Krüger et al., 2011) by analysing ~20 – 70 individual fluid inclusions in each of the 34 growth bands along the growth axis of SSC01. The Holocene part of the record yields near Gaussian-shaped distributions within coeval fluid inclusion assemblages, while the glacial and early deglacial part shows a considerable spread among seemingly co-eval inclusions, with bimodal distributions. When applying a Gaussian deconvolution routine, we find that the warmer part of these distributions consistently yields temperatures resembling late deglacial or Holocene temperatures. Temperatures of the colder mode of the distributions, in contrast, reflect glacial and deglacial conditions showing a clear deglacial warming trend that closely follows atmospheric CO2 and Southern Hemisphere warming.We hypothesize that the warmer mode of these bimodal distributions is a result of open porosity, networks of interconnected cavities that sealed off from the environment towards the end of the glacial Termination, i.e., at a temperature that was significantly higher than the formation temperature of the surrounding calcite host. This interpretation is further supported by petrographic observations, revealing that the glacial and deglacial part of the stalagmite is characterized by frequent alterations of columnar open fabrics (Frisia et al., 2015) and organic-rich micritic layers with high porosity. We suppose that open porosity in stalagmites can occur both vertically along the columnar crystal boundaries and also laterally along specific growth layers.Bimodal temperature distributions in seemingly coeval fluid inclusions can arise due to temporary open porosity, provided that the temperature difference between the different closing ages of the inclusions is large enough. Our findings emphasize the need for careful consideration of fabric-related factors that can affect the temperatures derived from fluid inclusions.  References:Frisia, S (2015). Microstratigraphic logging of calcite fabrics in speleothems as tool for palaeoclimate studies. Int. J. Speleol. 44, 1–16.Krüger, Y. et al. (2011). Liquid–vapour homogenisation of fluid inclusions in stalagmites: Evaluation of a new thermometer for palaeoclimate research. Chem. Geol. 289, 39–47.Partin, J.W., et al (2007). Millennial-scale trends in west Pacific warm pool hydrology since the Last Glacial Maximum. Nature 449, 452.

  PublisherDOI

• Regime shifts in Holocene paleohydrology as recorded by Asian Speleothems

  2024-08-28 · 1 citations

  preprintOpen access

  Oxygen isotope records from speleothem archives provide unique perspectives on the evolution of the Asian Monsoon.Recently, their precise chronologies have been used to pinpoint abrupt events, notably the onset of the proposed Meghalayan age (4.2 ky BP to present).This "4.2 ka event" coincides with an isotopic excursion in a speleothem record from Mawmluh cave, India, andhas been associated with several civilization collapses throughout Asia, though controversy surrounds their causes and timing.Here we use 14 well-dated speleothem oxygen isotope records from the SISAL v3 database and the recent literature to investigate the regional coherency of rapid (centennial-millennial) shifts in Asian paleohydrology over the Holocene.A suite of robust methods fails to detect spatially coherent variability consistent with an event at 4.2 ka across Asia at these time scales, either because none exists, or because it is of insufficient magnitude to be detected.In contrast, the 8.2k event is expressed in the majority of the records that resolve it.The absence of a clearly expressed isotopic excursion across this dataset suggests that the "4.2 ka megadrought" was not global, which has important implications for archeology and geochronology.In particular, it casts doubt on the proposal that the 4.2 ka event marks the onset of a new geologic age.We do however observe support for the occurrence of a gradual isotopic enrichment between 3.9ka and 3.6ka, followed by a partial recovery -consistent with the "Double Drying" hypothesis, and plausibly related to changes in the variability of the ENSO.

  PublisherOA PDFDOI

• Globally coherent water cycle response to temperature change during the past two millennia

  Nature Geoscience · 2023 · 38 citations

  • Climatology
  • Environmental science
  • Atmospheric sciences
  PublisherOA PDFDOI

• Unraveling forced responses of extreme El Niño variability over the Holocene

  Science Advances · 2022-03-04 · 28 citations

  articleOpen access

  Uncertainty surrounding the future response of El Niño-Southern Oscillation (ENSO) variability to anthropogenic warming necessitates the study of past ENSO sensitivity to substantial climate forcings over geological history. Here, we focus on the Holocene epoch and show that ENSO amplitude and frequency intensified over this period, driven by an increase in extreme El Niño events. Our study combines new climate model simulations, advances in coral proxy system modeling, and coral proxy data from the central tropical Pacific. Although the model diverges from the observed coral data regarding the exact magnitude of change, both indicate that modern ENSO variance eclipsed paleo-estimates over the Holocene, albeit against the backdrop of wide-ranging natural variability. Toward further constraining paleo-ENSO, our work underscores the need for multimodel investigations of additional Holocene intervals alongside more coral data from periods with larger climate forcing. Our findings implicate extreme El Niño events as an important rectifier of mean ENSO intensity.

  PublisherDOI

• Mulu Borneo stalagmite SC02 d18O and d13C 19.5-10.7 ky BP

  Zenodo (CERN European Organization for Nuclear Research) · 2022-02-09

  datasetOpen access

  Here are presented Mulu, Borneo (4°6’N, 114°53’E) Secret Cave stalagmite SC02 d18O and d13C values over Termination 1, published in Buckingham et al. (accepted). U-Th ages were calculated using the initial detrital 230Th/232Th value of 111 ± 41 ppm. A Matlab Monte Carlo script was used to calculated the absolute age and age errors associated with each U-Th sample. The Poisson-process deposition model feature in OxCal(v4.4) was used to interpolate between the eighteen U/Th ages to produce an age model. This study reports a d18O and d13C record for the portion of SC02 104.1 to 182.4 mm distance from top of stalagmite. The d18O record spans the full deglaciation, and reveals distinct d18O variations connected with the Bølling-Allerød onset and the Younger Dryas event.

  PublisherDOI

• Isotopic variability in tropical cyclone precipitation is controlled by Rayleigh distillation and cloud microphysics

  Communications Earth & Environment · 2022 · 45 citations

  • Environmental science
  • Climatology
  • Atmospheric sciences

  Abstract Tropical cyclones produce rainfall with extremely negative isotope values (δ 18 O and δ 2 H), but the controls on isotopic fractionation during tropical cyclones are poorly understood. Here we studied the isotopic composition of rainfall at sites across central Texas during Hurricane Harvey (2017) to better understand these processes. Rainfall δ 18 O trend towards more negative values as a result of Rayleigh distillation of precipitation-generating airmasses as they travel towards the center of the storm. Superimposed on these gradual changes are abrupt isotopic shifts with exceptionally low deuterium excess values. These appear to be controlled by microphysical processes associated with the passage of spiral rainbands over the sampling locations. Isotope-enabled climate modeling suggests that it may be possible to identify the signature of tropical cyclones from annually resolved isotopic proxy records, but will depend on the size of the storm and the proximity of the site to the core of the storm system.

  PublisherOA PDFDOI

• Mulu Borneo stalagmite SC02 d18O and d13C 19.5-10.7 ky BP

  Zenodo (CERN European Organization for Nuclear Research) · 2022-02-09

  datasetOpen access

  Here are presented Mulu, Borneo (4°6’N, 114°53’E) Secret Cave stalagmite SC02 d18O and d13C values over Termination 1, published in Buckingham et al. (accepted). U-Th ages were calculated using the initial detrital 230Th/232Th value of 111 ± 41 ppm. A Matlab Monte Carlo script was used to calculated the absolute age and age errors associated with each U-Th sample. The Poisson-process deposition model feature in OxCal(v4.4) was used to interpolate between the eighteen U/Th ages to produce an age model. This study reports a d18O and d13C record for the portion of SC02 104.1 to 182.4 mm distance from top of stalagmite. The d18O record spans the full deglaciation, and reveals distinct d18O variations connected with the Bølling-Allerød onset and the Younger Dryas event.

  PublisherDOI

Recent grants

• P2C2: Orbital Forcing of South Indian Hydroclimate

  NSF · $483k · 2017–2021

• Fossil Coral Records of ENSO during the Last Glacial Period

  NSF · $477k · 2018–2020

• P2C2: Western Pacific Warm Pool Hydroclimate during the Last Glacial Maximum and the Deglaciation

  NSF · $530k · 2014–2017

• Collaborative Research: Holocene Hydrologic Variability across the Western Pacific Warm Pool

  NSF · $504k · 2011–2014

Frequent coauthors

• Terrence M. Quinn

  The University of Texas at Austin

  42 shared

• Kaustubh Thirumalai

  University of Arizona

  34 shared

• Jay L. Banner

  The University of Texas at Austin

  26 shared

• Chuan–Chou Shen

  National Taiwan University

  23 shared

• C. R. Maupin

  Texas A&M University

  20 shared

• Frederick W. Taylor

  The University of Texas at Austin

  18 shared

• F. W. Taylor

  16 shared

• John W. Jenson

  University of Guam

  16 shared