A5039166972- Atmospheric chemistry and aerosols
- Marine and coastal ecosystems
- Mercury impact and mitigation studies
- Atmospheric and Environmental Gas Dynamics
- Geochemistry and Elemental Analysis
- Heavy metals in environment
- Geology and Paleoclimatology Research
- Geochemistry and Geologic Mapping
- Groundwater and Isotope Geochemistry
- Atmospheric aerosols and clouds
- Methane Hydrates and Related Phenomena
- Air Quality Monitoring and Forecasting
- Fern and Epiphyte Biology
- Oceanographic and Atmospheric Processes
- Atmospheric Ozone and Climate
- Radioactivity and Radon Measurements
- Arctic and Antarctic ice dynamics
- Lichen and fungal ecology
- Marine Biology and Ecology Research
- Plant Water Relations and Carbon Dynamics
- Cyclone Separators and Fluid Dynamics
- Isotope Analysis in Ecology
- Climate change and permafrost
- Marine animal studies overview
- Geomagnetism and Paleomagnetism Studies
University of Georgia
2013-2025
Skidaway Institute of Oceanography
2015-2025
Florida State University
2006-2014
Woodward (United States)
2008-2013
University of California, Santa Cruz
2008-2013
Old Dominion University
2010
The GEOTRACES Intermediate Data Product 2017 (IDP2017) is the second publicly available data product of international programme, and contains measured quality controlled before end 2016. IDP2017 includes from Atlantic, Pacific, Arctic, Southern Indian oceans, with about twice volume previous IDP2014. For first time, for a large suite biogeochemical parameters as well aerosol rain characterising atmospheric trace element isotope (TEI) sources. TEI in are by careful assessment intercalibration...
With the Arctic rapidly changing, needs to observe, understand, and model changes are essential. To support these needs, an annual cycle of observations atmospheric properties, processes, interactions were made while drifting with sea ice across central during Multidisciplinary Observatory for Study Climate (MOSAiC) expedition from October 2019 September 2020. An international team designed implemented comprehensive program document characterize all aspects system in unprecedented detail,...
Atmospheric deposition is a source of potentially bioavailable iron (Fe) and thus can partially control biological productivity in large parts the ocean. However, explanation observed high aerosol Fe solubility compared to that soil particles still controversial, as several hypotheses have been proposed explain this observation. Here, statistical analysis estimated from four models observations compiled multiple field campaigns suggests pyrogenic aerosols are main sources with at low...
Dust aerosol samples were collected across the western North Pacific Ocean during May–June 2002. Samples analyzed for soluble Fe(II), Fe(II) + Fe(III), and Al as well major cations anions. The leached using a 10 second exposure to either filtered surface seawater or ultrapure deionized water yielding measure of “instantaneous” fraction. A variety analytical methods employed, including 57 Fe isotope dilution high‐resolution ICP‐MS, energy dispersive X‐ray fluorescence, graphite furnace AAS,...
Atmospheric deposition of trace elements and isotopes (TEI) is an important source metals to the open ocean, impacting TEI budgets distributions, stimulating oceanic primary productivity, influencing biological community structure function. Thus, accurate sampling aerosol TEIs a vital component ongoing GEOTRACES cruises, standardized analysis procedures allow comparison data from different sites investigators. Here, we report results intercalibration study by seventeen laboratories for...
Trace element sampling and shipboard flow injection analysis during the June–August 2003 Climate Variability Predictability (CLIVAR)‐CO 2 Repeat Hydrography A16N transect has produced a high‐resolution section of dissolved Fe Al in upper 1000 m Atlantic Ocean between 62°N 5°S. Using surface water Model Aluminum for Dust Calculation Oceanic Waters (MADCOW) model we have calculated deposition mineral dust to ocean along this compare that concentrations. The lowest mean depositions ≤0.2 g −2 −1...
Recent trends of atmospheric lead deposition to the North Pacific were investigated with analyses in aerosols and surface waters collected on fourth Intergovernmental Oceanographic Commission Contaminant Baseline Survey from May June, 2002. Lead concentrations varied by 2 orders magnitude (0.1-26.4 pmol/m(3)) due part variations dust during cruise. The ranges aerosol enrichment factors relative iron (1-119) aluminum (3-168) similar, evidencing transport Asian industrial across Pacific....
Abstract. Atmospheric processing of iron in dust and combustion aerosols is simulated using an intermediate-complexity soluble mechanism designed for Earth system models. The solubilization includes both a dependence on aerosol water pH in-cloud oxalic acid. simulations size-resolved total, fractional solubility indicate that this captures many but not all the features seen from cruise observations labile iron. primary objective was to determine extent which our scheme could adequately match...
Abstract Despite the Pacific being location of earliest seawater Cd studies, processes which control distributions in this region remain incompletely understood, largely due to sparsity data. Here, we present dissolved and δ 114 data from US GEOTRACES GP15 meridional transect along 152°W Alaskan margin equatorial Pacific. Our examination region's surface ocean isotope systematics is consistent with previous observations, showing a stark disparity between northern Cd‐rich high‐nutrient...
To obtain trace element data sets of sufficient resolution to resolve and interpret biogeochemical features, it is necessary develop sampling schemes that are fast reliable, retrieve uncontaminated samples, consistent with the new global‐ranging oceanographic programs. We present here a detailed description rosette‐based system for determinations meets these criteria. It has been used successfully on several CLIVAR cruises required high‐resolution elements, also biological studies where...
Abstract Atmospheric deposition is an important but still poorly constrained source of trace micronutrients to the open ocean because dearth in situ measurements total (i.e., wet + dry deposition) remote regions. In this work, we discuss upper distribution dissolved Fe and Al eastern Indian Ocean along a 95°E meridional transect spanning Antarctic margin Bay Bengal. We use mixed layer concentration conjunction with empirical data simple steady state model produce 75 estimates dust that...
The international GEOTRACES program has allowed unprecedented access to aerosols in the remote marine environment, moved community toward standardized methodologies, and contributed expanding research capabilities around globe. A key aspect of aerosol is quantification deposition fluxes trace elements isotopes surface ocean as a source for biolimiting nutrients anthropogenic contaminants. New methods quantifying flux have been developed that leverage radioisotope tracers estimate bulk rates...
Abstract The transport and delivery of low‐abundance, bioactive trace elements to the surface ocean by aerosol mineral dust is a major planetary control over marine primary production hence global carbon cycle. Variations in concentration atmospheric have established links climate geologic timescales regional biogeographic shifts seasonal timescales. Constraining variability thus high value understanding oceanographic systems, especially vast, constitutively low‐nutrient subtropical gyre...
Abstract Atmospheric deposition is an important source of iron (Fe) and perhaps zinc (Zn) to the oceans. We present total water‐soluble aerosol Fe Zn isotopic compositions, size‐fractionated enrichment factors from North Pacific GEOTRACES GP15 section (Alaska‐Tahiti) during low dust season. found distinct bulk provinces along this latitudinal transect: Asian aerosols (especially crustal dust) dominate at higher latitudes (52–32°N) while American heavier‐than‐crustal wildfire in Equatorial...
Abstract A high‐resolution section of dissolved iron (dFe) and aluminum (dAl) was obtained along ~95°E in the upper 1000 m eastern Indian Ocean from Antarctic margin (66°S) to Bay Bengal (18°N) during U.S. Climate Variability Predictability (CLIVAR) CO 2 Repeat Hydrography I08S I09N sections (February–April 2007). In Southern Ocean, low concentrations dAl (<1 n M ) reflect negligible dust inputs impacting water masses subducted circumpolar domain. The characterizing terminate near 45°S,...
Abstract This study provides unique insights into the properties of iron (Fe) in marine atmosphere over late summertime Arctic Ocean. Atmospheric deposition aerosols can deliver Fe, a limiting micronutrient, to remote ocean. Aerosol particle size influences aerosol Fe fractional solubility and air-to-sea rate. Size-segregated were collected during 2015 US GEOTRACES cruise Results show that had single-mode distribution, peaking at 4.4 µm diameter, suggesting regional dust sources around...
Abstract Atmospheric deposition of aerosols transported from the continents is an important source nutrient and pollutant trace elements (TEs) to surface ocean. During U.S. GEOTRACES GP15 Pacific Meridional Transect between Alaska Tahiti (September–November 2018), aerosol samples were collected over North equatorial analyzed for a suite TEs, including Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Pb. Sampling coincided with annual minimum in dust transport Asia, providing opportunity quantify TE...
Abstract Recent analyses suggest that considerable CaCO 3 dissolution may occur in the upper water column of ocean (< 1500 m). This study uses distribution particulate calcium from high‐resolution suspended matter sampling along Climate Variability and Predictability/CO 2 Repeat Hydrography A16N transect 2003 to estimate top 1000 m North Atlantic. Dissolution rates were also approximated using changes total alkalinity measurements isopycnal surfaces. Water masses found be undersaturated...