A5008890165- Geology and Paleoclimatology Research
- Cryospheric studies and observations
- Atmospheric and Environmental Gas Dynamics
- Atmospheric chemistry and aerosols
- Microplastics and Plastic Pollution
- Fire effects on ecosystems
- Karst Systems and Hydrogeology
- Heavy metals in environment
- Archaeology and ancient environmental studies
- Mercury impact and mitigation studies
- Isotope Analysis in Ecology
- Maritime and Coastal Archaeology
- Geological formations and processes
- Polar Research and Ecology
- Climate change and permafrost
- Precipitation Measurement and Analysis
- Paleontology and Stratigraphy of Fossils
- Groundwater and Isotope Geochemistry
- Aeolian processes and effects
- Atmospheric Ozone and Climate
- Recycling and Waste Management Techniques
- Meteorological Phenomena and Simulations
- Pleistocene-Era Hominins and Archaeology
- Tree-ring climate responses
- Toxic Organic Pollutants Impact
Desert Research Institute
2016-2025
University of Miami
2010-2021
Significance An 1100 BCE to 800 CE record of estimated lead emissions based on continuous, subannually resolved, and precisely dated measurements pollution in deep Greenland ice atmospheric modeling shows that European closely varied with historical events, including imperial expansion, wars, major plagues. Emissions rose coeval Phoenician expansion accelerated during expanded Carthaginian Roman lead–silver mining primarily the Iberian Peninsula. fluctuated synchronously wars political...
Significance Cold and dry glacial-state climate conditions persisted in the Southern Hemisphere until approximately 17.7 ka, when paleoclimate records show a largely unexplained sharp, nearly synchronous acceleration deglaciation. Detailed measurements Antarctic ice cores document exactly at that time unique, ∼192-y series of massive halogen-rich volcanic eruptions geochemically attributed to Mount Takahe West Antarctica. Rather than coincidence, we postulate halogen-catalyzed stratospheric...
Abstract Forest fires are increasing across the American West due to climate warming and fire suppression. Accelerated snow melt occurs in burned forests increased light transmission through canopy decreased albedo from deposition of light-absorbing impurities. Using satellite observations, we document up an annual 9% growth western since 1984, 5 day earlier disappearance persisting for >10 years following fire. Here, show that black carbon woody debris darkens snowpack lowers 15 winters...
Abstract. Stable isotope records from speleothems provide information on past climate changes, most particularly that can be used to reconstruct changes in precipitation and atmospheric circulation. These are increasingly being “out-of-sample” evaluations of isotope-enabled models. SISAL (Speleothem Isotope Synthesis Analysis) is an international working group the Past Global Changes (PAGES) project. The aims a comprehensive compilation speleothem for reconstruction model evaluation....
Significance Our measurements show a tripling of iodine in Alpine ice between 1950 and 1990. A 20th century increase global emissions has been previously found from model simulations, based on laboratory studies, but, up to now, long-term records exist only polar regions. These are influenced by sea processes, which may obscure trends. results suggest that the increased deposition over Alps is consistent with oceanic coupled change speciation, both driven increasing anthropogenic NO x...
Lead pollution in Arctic ice reflects large-scale historical changes midlatitude industrial activities such as ancient lead/silver production and recent fossil fuel burning. Here we used measurements a broad array of 13 accurately dated cores from Greenland Severnaya Zemlya to document spatial temporal lead 200 BCE 2010 CE, with interpretation focused on 500 CE. Atmospheric transport modeling indicates that was primarily European emissions before the 19th-century Industrial Revolution....
Lithium (Li) concentrations in drinking-water supplies are not regulated the United States; however, Li is included 2022 U.S. Environmental Protection Agency list of unregulated contaminants for monitoring by public water systems. used pharmaceutically to treat bipolar disorder, and studies have linked its occurrence drinking human-health outcomes. An extreme gradient boosting model was developed estimate geogenic supply wells throughout conterminous States. The trained using measurements...
Abstract Lead and antimony measurements in basal ice from the Col du Dome glacier document heavy metal pollution western Europe associated with emissions mining smelting operations during European antiquity. Radiocarbon dating of particulate organic carbon fraction suggests that dates to ~5,000 ± 600 cal years BP. In agreement a precisely dated Greenland lead record, record indicates two periods significant Roman period, is, last centuries before Common Era second century Era. Atmospheric...
Atmospheric nuclear weapons testing (NWT) resulted in the injection of plutonium (Pu) into atmosphere and subsequent global deposition. We present a new method for continuous semiquantitative measurement (239)Pu ice cores, which was used to develop annual records fallout from NWT ten cores Greenland Antarctica. The measured directly using an inductively coupled plasma-sector field mass spectrometer, thereby reducing analysis time increasing depth-resolution with respect previous methods. To...
Plastics in aquatic ecosystems rapidly undergo biofouling, giving rise to a new ecosystem on their surface, the 'plastisphere.' Few studies quantify impact of plastics and associated community traits from biodiversity functional metabolic function. It has been suspected that impacts may depend its state but comparative responses are rare published literature. We quantified algal biomass, bacterial (16S 18S rRNA), growing surface different plastic polymers incubated within rivers Lower Mekong...
Partitioning precipitation into rain and snow with near-surface meteorology is a well-known challenge. However, whether limit exists to its potential performance remains unknown. Here, we evaluate this possibility by applying set of benchmark phase partitioning methods plus three machine learning (ML) models (an artificial neural network, random forest, XGBoost) two independent datasets: 38.5 thousand crowdsourced observations 17.8 million synoptic reports. The ML provide negligible...
Updated preindustrial fire emissions consistent with ice core records reduce the magnitude of estimated aerosol radiative forcing.
The Upper Fremont Glacier (UFG), Wyoming, is one of the few continental glaciers in contiguous United States known to preserve environmental and climate records spanning recent centuries. A pair ice cores taken from UFG have been studied extensively document changes industrial pollution (most notably, mid-19th century increases mercury pollution). Fundamental these studies chronology used map ice-core depth age. Here, we present a revised for based on new measurements using novel dating...
Chronic exposure to high levels of arsenic in drinking water can have wide-ranging health effects and is a global concern. The domestic well population the western Great Basin (WGB) at increased risk due hydrologic, geologic, climatic setting region. A logistic regression (LR) model was developed predict probability elevated (≥5 μg/L) alluvial aquifers assess potential geologic hazard level posed populations. Alluvial are susceptible contamination, which concern because they primary source...
The hydrogen and oxygen isotopic analyses (δ(2)H δ(18)O values) of water trapped within speleothem carbonate (fluid inclusions) have traditionally been conducted utilizing dual-inlet isotope ratio mass spectrometry (IRMS) or continuous-flow (CF)-IRMS methods. application cavity ring-down spectroscopy (CRDS) to the δ(2)H analysis in fluid inclusions has investigated at University Miami as an alternative method CF-IRMS.An extraction line was developed recover from consisting a crusher, sample...
Abstract Using the clumped isotope method, temperature of dolomite and calcite formation oxygen isotopic composition (δ 18 O w ) diagenetic fluids have been determined in a core taken from Arab‐D Ghawar field, largest oil reservoir world. These analyses show that while dolomites limestones throughout major zones recrystallized at temperatures between ca 80°C 100°C, carbonates near top formed significantly lower (20 to 30°C). Although δ values large variations ranging <0‰ +8‰, exhibit...
Abstract Black carbon (BC) and other biomass‐burning (BB) aerosols are critical components of climate forcing, but quantification, predictive modeling, policy decisions have been hampered by limited understanding the drivers BB lack long‐term records. Prior modeling studies suggested that increased Northern Hemisphere anthropogenic BC emissions recent temperatures regional precipitation, including a northward shift in Intertropical Convergence Zone (ITCZ). Two Antarctic ice cores were...
Speleothem oxygen isotope records from the Caribbean, Central, and North America reveal climatic controls that include orbital variation, deglacial forcing related to ocean circulation ice sheet retreat, influence of local remote sea surface temperature variations. Here, we review these global climate teleconnections they suggest following recent publication Isotopes Synthesis Analysis (SISAL) database. We find low-latitude generally reflect changes in precipitation, whereas higher latitude...
Abstract Pollutants emitted by industrial processes are deposited across the landscape. Ice core records from mid‐latitude glaciers located close to emission sources document history of local‐to‐regional pollution since preindustrial times. Such underpin attribution pollutants specific critical developing abatement policies. Previous ice studies Alps overall magnitude and timing related nitrogen sulfur‐derived species, as well a few metals including lead. Here, we used subannually resolved...
The duration and maximum combustion temperature of vegetation fires are important fire properties with implications for ecology, hydrology, hazard potential, many other processes. Directly measuring during is difficult. However, chemical transformations associated reflected in the charcoals (a by-product fire). Therefore, charcoal could be used indirectly to determine application palaeoecological records. To evaluate reliability chemistry as an indicator temperature, we studied formed...