Emily Judd

• PhD
• PostDoc Position at Smithsonian Institution

A long-term record of global mean surface temperature (GMST) provides critical insight into the dynamical limits of Earth’s climate and the complex feedbacks between temperature and the broader Earth system. Here, we present PhanDA, a reconstruction of GMST over the past 485 million years, generated by statistically integrating proxy data with clim...

Paleotemperature proxy data form the cornerstone of paleoclimate research and are integral to understanding the evolution of the Earth system across the Phanerozoic Eon. Here, we present PhanSST, a database containing over 150,000 data points from five proxy systems that can be used to estimate past sea surface temperature. The geochemical data hav...

Ongoing global warming due to anthropogenic climate change has long been recognized, yet uncertainties regarding how seasonal extremes will change in the future persist. Paleoseasonal proxy data from intervals when global climate differed from today can help constrain how and why the annual temperature cycle has varied through space and time. Recor...

Plain Language Summary Geochemical analyses provide estimates of past sea surface temperature. These data are integral to calculating global climate metrics, such as the latitudinal temperature gradient. For myriad reasons, the sites of these data are not evenly distributed across the global oceans but, instead, are biased toward two environments—c...

Understanding conditions at both global and local scales during the greenhouse climate of the Eocene Epoch is critical for making accurate predictions in our rapidly warming world. Despite the wealth of proxy data and modeling studies, fundamental aspects of the climate system still remain uncertain. For example, accurate austral high‐latitude temp...

Reconstructions of past climates in both time and space provide important insight into the range and rate of change within the climate system. However, producing a coherent global picture of past climates is difficult because indicators of past environmental changes (proxy data) are unevenly distributed and uncertain. In recent years, paleoclimate...

Paleoclimate data assimilation (DA) is a tool for reconstructing past climates that directly integrates proxy records with climate model output. Despite the potential for DA to expand the scope of quantitative paleoclimatology, these methods remain difficult to implement in practice due to the multi-faceted requirements and data handling necessary...

The stable oxygen (δ18Oshell) and carbon (δ13Cshell) isotope ratios retrieved from the carbonate shell of terrestrial gastropods can be used as an environmental proxy and are thought to reflect dietary composition and ambient climatic conditions (e.g. precipitation amount, humidity, temperature). Here, we generate high-resolution isotopic profiles...

Paleoclimate data assimilation (DA) is a novel tool for reconstructing past climates that directly integrates proxy records with climate model output. Despite the potential for DA to expand the scope of quantitative paleoclimatology, these methods remain difficult to implement in practice due to the multi-faceted requirements and data handling nece...

Daily weather reconstructions (called “reanalyses”) can help improve our understanding of meteorology and long-term climate changes. Adding undigitized historical weather observations to the datasets that underpin reanalyses is desirable; however, time requirements to capture those data from a range of archives is usually limited. Southern Weather...

Oxygen isotope values of shell carbonate sampled along the growth trajectory of fossil mollusks provide one of the few types of proxy data available for reconstructing seasonal temperature variation in Earth's past. Understanding how diagenesis affects the preservation of seasonal cycles is key to their interpretation in a paleoclimate context. An...

Nitrogen stable isotopes (δ15N) of organic matter can aid in the reconstruction of food webs and, when applied to fossil systems, may help resolve uncertainty about trophic position and provide tests for hypotheses developed using traditional paleoecological techniques. However, in order to use those values to reconstruct trophic relationships in e...

Continental rifts are important sources of mantle carbon dioxide (CO2) emission into Earth’s atmosphere1–3. Because deep carbon is stored for long periods in the lithospheric mantle4–6, rift CO2 flux depends on lithospheric processes that control melt and volatile transport1,3,7. The influence of compositional and thickness differences between Arch...

Use of the δ ¹⁸ O thermometer in deep time investigations is complicated by uncertainty in the oxygen isotopic composition of seawater and an increasing potential for diagenetic alteration with age. These concerns are particularly important when considering that δ ¹⁸ O values from Paleozoic marine carbonates tend to be low and increasingly depleted...

The paired analysis of subannual microincrements and serially-sampled oxygen isotope data affords insights into the physiological and environmental conditions controlling bivalve growth. However, daily microincrements are faint or absent in many taxa, difficult or ambiguous to count under the best conditions, and are often constrained to the earlie...

Mean body size in marine animals has increased more than 100-fold since the Cambrian, a discovery that brings to attention the key life-history parameters of lifespan and growth rate that ultimately determine size. Variation in these parameters is not well understood on the planet today, much less in deep time. Here, we present a new global databas...

As we head toward a warmer world, it is increasingly important to understand anticipated changes in temperature and precipitation and consequent shifts in storm trajectory and intensity. One of the best tools we have for predicting future conditions is the study of warm intervals in Earth’s geologic past, such as the Eocene Epoch (56-34 Ma), charac...

Segmentation along normal faults is often expressed as a mountain salient that separates fault-bounded valleys to either side. Segment boundaries are areas of lower cumulative slip and thus their faults typically cut through bedrock units making it challenging to determine the age of recent earthquakes. However, bracketing the age of such earthquak...