Publications

Diatom records from the East Pisco Basin (EPB) of southern Peru and offshore Ocean Drilling Program (ODP) Hole 682 A reveal stepwise increases in the primary productivity of the Humboldt Current during the middle and late Miocene. Although diatoms are present back through the late middle Eocene, successively enhanced diatom production occurs during the Miocene in four steps. The first...

The scale and magnitude of urban heating are often assessed using Satellite-Derived Land Surface Temperature (SD-LST). Yet, discrepancies in spatial resolution limit SD-LST’s ability to reflect pedestrian thermal experience, potentially leading to ineffective mitigation strategies. Hyper-local measurements of urban heat, defined as surface temperatures (TS) at the scale of pedestrian...

Wetlands have spatially and temporally dynamic nitrous oxide (N2O) fluxes. Understanding diurnal patterns in N2O fluxes in wetlands can reveal short-term drivers and improve process-based models. An automated chamber system was used to determine N2O flux rates every 2.5 to 4 h in a prairie pothole wetland in North Dakota during the 2013 to 2014 growing seasons under ponded, moist, and...

The land carbon sink of the conterminous United States was evaluated using a bottom-up modeling framework and 30-meter land change data from 1985 to 2020. This cross-scale, cross-landscape, and cross-system approach tracked fractional land cover changes and applied regional model calibration. Results show average terrestrial and aquatic carbon sinks of +110 ± 37 and +19 ± 0.5 teragrams...

The critical carbon sink provided by coastal wetlands, known as blue carbon, can be affected by multiple aspects of climate change. One important example is warming-induced mangrove poleward expansion, which is shifting dominant plant cover across tropical–temperate transitional zones and altering ecosystem structure and function. We examined how mangrove expansion affects soil organic...

Arctic sea-ice loss affects biological productivity, sustenance in coastal communities, and geopolitics. Forecasting these impacts requires mechanistic understanding of how Arctic sea ice responds to climate change, but this is limited by scarce long-term records. We present continuous 30,000-year reconstructions of sea-ice coverage from the Arctic Ocean based on measurements of two...

Nitrous oxide (N2O), a potent greenhouse gas (GHG) and major contributor to climate change, is primarily released through agricultural activities. To better understand and quantify how land management practices, local climate conditions, and soil physicochemical properties affect these agricultural N2O emissions, we conducted a review of the peer-reviewed literature on N2O emission from...

Bering Land Bridge (BLB) climate and vegetation during the Last Glacial Maximum (LGM) remains largely understudied, given challenges associated with collecting records from the submerged BLB. Previous records, confined to the margins of the modern land area and adjacent shelf, reveal conflicting interpretations of Beringian vegetation during the LGM. Here, we reconstruct LGM vegetation

Increased urban heat intensifies thermal discomfort, particularly in critical public spaces such as transit stops. This study investigated the predictors of transit users' thermal perceptions in Denver, Colorado—a semi-arid city. Sixty bus stops spanning a gradient of land cover compositions were selected for study. Micrometeorological data, including thermal comfort indices, were...

Salt marshes are dynamic biogeomorphic systems reliant on autochthonous and allochthonous input to maintain their three-dimensional configuration. Sea-level rise, subsidence, and sediment deficits can lead to submergence, open-water expansion, and ultimately loss of the vegetated marsh plain and associated ecosystem services. Widely used management-focused models focus on vegetation...

The diatom biochronology of ODP (Ocean Drilling Program) Holes 682A and 688E provides a detailed framework for refiningMiocene diatom zonation in the East Pisco Basin of southern Peru, establishing both a nearly complete offshore reference section and a correlation tool for the fragmentary onshore vertebrate-bearing deposits. This new biostratigraphic record documents a complete...

The Pliocene Yorktown Formation, deposited on the U.S. Mid-Atlantic Coastal Plain, has played an important role in advancing our knowledge of Pliocene paleoclimate. To refine the age and paleoenvironment of the Yorktown Formation, we analyzed the calcareous nannofossil assemblage and compared it with variations in lithology and calculated sea surface temperature (SST) from previous...