Scott Elliott

Scott Elliott
Los Alamos National Laboratory | LANL · CCS

About

115
Publications
18,633
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3,114
Citations
Citations since 2017
12 Research Items
1321 Citations
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2017201820192020202120222023050100150200250
2017201820192020202120222023050100150200250
2017201820192020202120222023050100150200250

Publications

Publications (115)
Article
Full-text available
Rivers of the Arctic will become ever more important for the global climate, since they carry a majority of continental dissolved organic carbon flux into the rapidly changing polar ocean. Aqueous organics comprise a wide array of functional groups, several of which are likely to impact coastal and open water biophysical properties. Light attenuati...
Article
Full-text available
We have recently argued that marine interfacial surface tension must have a distinctive biogeography because it is mediated by fresh surfactant macromolecules released locally through the food web. Here we begin the process of quantification for associated climate flux implications. A low dimensionality (planar) equation of state is invoked at the...
Article
Dimethyl sulfide (DMS), primarily produced by marine organisms, contributes significantly to sulfate aerosol loading over the ocean after being oxidized in the atmosphere. In addition to exerting a direct radiative effect, the resulting aerosol particles act as cloud condensation nuclei, modulating cloud properties and extent, with impacts on atmos...
Article
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We apply principles of Gibbs phase plane chemistry across the entire ocean-atmosphere interface to investigate aerosol generation and geophysical transfer issues. Marine surface tension differences comprise a tangential pressure field controlling trace gas fluxes, primary organic inputs, and sea spray salt injections, in addition to heat and moment...
Article
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The OCEANFILMS parameterization for sea-spray organic aerosol emissions has been implemented into a global Earth system model, the Energy Exascale Earth System Model (E3SM). OCEANFILMS is a physically-based model that links sea spray chemistry with ocean biogeochemistry using a Langmuir partitioning approach. Here we describe the implementation wit...
Article
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The effort to accurately estimate global radiative forcing has long been hampered by a degree of uncertainty in the tropospheric aerosol contribution. Reducing uncertainty in natural aerosol processes, the baseline of the aerosol budget, thus becomes a fundamental task. The appropriate representation of aerosols in the marine boundary layer (MBL) i...
Article
Full-text available
Utilizing the reduced-complexity model Hector, a regional scale analysis was conducted quantifying the possible effects climate change may have on dimethyl sulfide (DMS) emissions within the oceans. The investigation began with a review of the sulfur cycle in modern Earth system models. We then expanded the biogeochemical representation within Hect...
Article
Full-text available
Dimethyl sulfide (DMS) is a significant source of marine sulfate aerosol and plays an important role in modifying cloud properties. Fully coupled climate simulations using dynamic marine ecosystem and DMS calculations are conducted to estimate DMS fluxes under various climate scenarios and to examine the sign and strength of phytoplankton-DMS-clima...
Article
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The current coarse-resolution global Community Earth System Model (CESM) can reproduce major and large-scale patterns but is still missing some key biogeochemical features in the Arctic Ocean, e.g. low surface nutrients in the Canada Basin. We incorporated the CESM Version 1 ocean biogeochemical code into the Regional Arctic System Model (RASM) and...
Preprint
Full-text available
We apply principles of Gibbs phase plane chemistry to and across the entire ocean-atmospheric interface. Surface tension increments support a two dimensional, tangential pressure well known to determine rates of bulk gas, bubble, salt, spray and momentum transfer plus both sensible and latent heat fluxes. Hence it is worth asking whether tension ma...
Preprint
Full-text available
A numerical mechanism connecting ice algal ecodynamics with the buildup of organic macromolecules is tested within modeled pan-Arctic brine channels. The simulations take place offline in a reduced representation of sea ice geochemistry. Physical driver quantities derive from the global sea ice code CICE, including snow cover, thickness and interna...
Article
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Arctic sea ice extent has declined continuously for the past decade, owing partially to light absorption by black carbon (BC) and other impurities deposited on snow and the underlying pack. We present simulations for the contemporary period showing that the optical depth contributed by Arctic ice algal chlorophyll may be comparable during Boreal Sp...
Article
We examined the multi-year mean and variability of dimethyl sulfide (DMS) and its relationship to sulfate aerosols, as well as cloud microphysical and radiative properties. We conducted a 150-year simulation using pre-industrial conditions produced by the Community Earth System Model embedded with a dynamic DMS module. The model simulated the mean...
Article
Full-text available
A mechanism connecting ice algal ecodynamics with the buildup of organic macromolecules in brine channels is tested offline in a reduced model of pack geochemistry. Driver physical quantities are extracted from the global sea ice dynamics code CICE, including snow height, column thickness and internal temperature. The variables are averaged at the...
Article
Here we show that the addition of chemical interactions between soluble monosaccharides and an insoluble lipid surfactant monolayer improves agreement of modeled sea spray chemistry with observed marine aerosol chemistry. In particular, the alkane:hydroxyl mass ratio in modeled sea spray organic matter is reduced from a median of 2.73 to a range of...
Article
Full-text available
Organic macromolecules constitute a high percentage of remote sea spray. They enter the atmosphere through adsorption onto bubbles followed by bursting at the ocean surface, and go on to influence the chemistry of the fine mode aerosol. We present a global estimate of mixed-layer macromolecular distributions, driven by offline marine systems model...
Article
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Significance Most large mammals are endangered or vulnerable across the globe. Although the loss of charismatic fauna is of great concern, their role in ecosystem function remains poorly characterized. Here, we quantify one potential effect of the decline of large herbivores: the reduction of the greenhouse gas methane released as a byproduct of pl...
Article
Dimethyl sulfide (DMS) is a biogenic organosulfur compound which contributes strongly to marine aerosol mass and the determination of cloud condensation nuclei over the remote oceans. Since uncertainties in DMS flux to the atmosphere lead to large variations in climate forcing, the global DMS distribution has been the subject of increasingly comple...
Article
Atmospheric aerosols, suspended solid and liquid particles, act as nucleation sites for cloud drop formation, affecting clouds and cloud properties—ultimately influencing the cloud dynamics, lifetime, water path, and areal extent that determine the reflectivity (albedo) of clouds. The concentration Nd of droplets in clouds that influences planetary...
Article
Full-text available
Atmospheric aerosols, suspended solid and liquid particles, act as nucleation sites for cloud drop formation, affecting clouds and cloud properties—ultimately influencing the cloud dynamics, lifetime, water path, and areal extent that determine the reflectivity (albedo) of clouds. The concentration Nd of droplets in clouds that influences planetary...
Article
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Methane is an important greenhouse gas but characterizing production by source sector has proven difficult. Current estimates suggest herbivores produce ~20% (~76-189 Tg yr(-1) ) of methane globally, with wildlife contributions uncertain. We develop a simple and accurate method to estimate methane emissions and reevaluate production by wildlife. We...
Article
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The presence of a large fraction of organic matter in primary sea spray aerosol (SSA) can strongly affect its cloud condensation nuclei activity and interactions with marine clouds. Global climate models require new parameterizations of the SSA composition in order to improve the representation of these processes. Existing proposals for such a para...
Article
Full-text available
The presence of a large fraction of organic matter in primary sea spray aerosol (SSA) can strongly affect its cloud condensation nuclei activity and interactions with marine clouds. Global climate models require new parameterizations of the SSA composition in order to improve the representation of these processes. Existing proposals for such a para...
Article
The sources and composition of atmospheric marine aerosol particles (aMA) have been investigated with a range of physical and chemical measurements from open-ocean research cruises. This study uses the characteristic functional group composition (from Fourier transform infrared, or FTIR, spectroscopy) of aMA from five ocean regions to show that: (i...
Article
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Biogenic lipids and polymers are surveyed for their ability to adsorb at the water–air interfaces associated with bubbles, marine microlayers and particles in the overlying boundary layer. Representative ocean biogeochemical regimes are defined in order to estimate local concentrations for the major macromolecular classes. Surfactant equilibria and...
Chapter
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The Pacific Arctic region (PAR) is experiencing atmospheric changes, rapid seasonal sea ice retreat, seawater warming, regional ocean acidification, along with other environmental changes and biological responses in lower to upper trophic organisms. Both physical and biogeochemical modeling indicate the potential for step-function changes to the ov...
Chapter
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At this early stage of modeling marine ecosystems and biogeochemical cycles in the Pacifi c Arctic Region (PAR), numerous challenges lie ahead. Observational data used for model development and validation remain sparse, especially across seasons and under a variety of environmental conditions. Field data are becoming more available, but at the same...
Conference Paper
Our estimates show an increase in dimethyl sulfide (DMS) flux over the Southern Ocean, a result of the poleward shift and strengthening of the southern westerly winds. DMS flux increases sharply between 55-60° S, ~ 25 percent, coinciding with increased winds. Since the 1950s, we estimate that DMS flux has increased 45 percent. Analysis shows consid...
Article
Full-text available
A highly potent greenhouse gas, methane, is locked in the solid phase as ice-like deposits containing a mixture of water and gas (mostly methane) called clathrates in both ocean sediments and underneath permafrost regions. Clathrates are stable under high pressures and low temperatures. In a warming climate, increases in ocean temperatures could le...
Article
Full-text available
The climatically-important compound dimethylsulfide (DMS) has been reported to be abundant in the Arctic, particularly in the marginal sea ice zone. Due to these high concentrations, it may play an important role in climate control. A DMS monthly climatology for July through October was created employing various ocean characteristics and spatial mo...
Article
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24 Dimethyl sulfide (DMS) is a major precursor for aerosols and cloud condensation 25 nuclei in the marine boundary layer over much of the ocean. Here we report on 60-year 26 simulations with a state-of-the-art global ocean biogeochemical model for DMS 27 distribution and fluxes using present-day and future atmospheric CO 2 concentrations. We 28 fi...
Article
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A dynamic model is constructed for interactive silicon, nitrogen, sulfur processing in and below Arctic sea ice, by ecosystems residing in the lower few centimeters of the distributed pack. A biogeochemically active bottom layer supporting sources/sinks for the pennate diatoms is appended to thickness categories of a global sea ice code. Nutrients...
Article
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As a part of Arctic Ocean Intercomparison Project, results from five coupled physical and biological ocean models were compared for the Arctic domain, defined here as north of 66.6°N. The global and regional (Arctic Ocean (AO)-only) models included in the intercomparison show similar features in terms of the distribution of present-day water column...
Article
As a part of Arctic Ocean Intercomparison Project, results from five coupled physical and biological ocean models were compared for the Arctic domain, defined here as north of 66.6°N. The global and regional (Arctic Ocean (AO)–only) models included in the intercomparison show similar features in terms of the distribution of present-day water column...
Conference Paper
Chemical cycling between the various Earth system components (atmosphere, biosphere, land, ocean, and sea-ice) can cause positive and negative feedbacks on the climate system. The long-standing CLAW/GAIA hypothesis proposed that global warming might stimulate increased production of dimethyl sulfide (DMS) by plankton in the ocean, which would then...
Article
A highly potent greenhouse gas, methane, is locked in the solid phase as ice-like deposits containing a mixture of water and gas (mostly methane) called clathrates, in ocean sediments and underneath permafrost regions. Clathrates are stable under high pressure and low temperatures. Recent estimates suggest that about 1600 - 2000GtC of clathrates ar...
Article
Vast quantities of methane are trapped in oceanic hydrate deposits, and there is concern that a rise in the ocean temperature will induce dissociation of these hydrate accumulations, potentially releasing large amounts of carbon into the atmosphere. Because methane is a powerful greenhouse gas, such a release could have dramatic climatic consequenc...
Article
Full-text available
An ice ecosystem model was coupled to a global dynamic sea ice model to assess large-scale variability of primary production and ice algal biomass within arctic sea ice. The component models are the Physical Ecosystem Model (PhEcoM) ice ecosystem model and the Los Alamos Sea Ice Model (CICE). Simulated annual arctic sea ice primary production was 1...
Article
A model for the vertical transport of passive tracers in sea ice is presented. Two Reynolds flux closure approximations are proposed for the tracer velocity dispersion term in the new ice tracer model (IceT). The schemes, ``enhanced molecular diffusion'' (EMD) and ``mixing length diffusion'' (MLD), are suggested parameterizations of gravity drainag...
Article
Full-text available
Geochemical environments, fates, and effects are modeled for methane released into seawater by the decomposition of climate-sensitive clathrates. A contemporary global background cycle is first constructed, within the framework of the Parallel Ocean Program. Input from organics in the upper thermocline is related to oxygen levels, and microbial con...
Article
Paleooceanographic evidence has been used to postulate that methane from oceanic hydrates may have had a significant role in regulating climate. However, the behavior of contemporary oceanic methane hydrate deposits subjected to rapid temperature changes, like those now occurring in the arctic and those predicted under future climate change scenari...
Article
Paleooceanographic evidence has been used to postulate that methane from oceanic hydrates may have had a significant role in regulating past global climate. However, the behavior of contemporary oceanic methane hydrate deposits subjected to rapid temperature changes, like those now occurring and those predicted under future climate change scenarios...
Article
Recent analysis of ocean transparency measurements and in situ chlorophyll observations indicate a global decline of ocean phytoplankton of ~40% since 1950. Global warming has increased stratification of the ocean surface, which is believed to be the cause. Because phytoplankton are the basis of the ocean food web, the importance of protecting this...
Conference Paper
One of the ways that the various Earth system components (land, atmosphere, ocean, and sea-ice) interact with each other is through chemical species, causing positive and negative feedbacks on the climate system. We will summarize the capabilities we have implemented within the Community Earth System Model (CESM, formerly known as CCSM) to simulate...
Article
An ice ecosystem model was coupled to a global dynamic sea ice model to assess large-scale variability of primary production and ice algal biomass within arctic sea ice. The component models are the ice ecosystem model developed at the International Arctic Research Center and the Los Alamos National Laboratory sea ice model, CICE. Simulated annual...
Article
Full-text available
Ocean dimethylsulfide (DMS) produced by marine biota is the largest natural source of atmospheric sulfur, playing a major role in the formation and evolution of aerosols, and consequently affecting climate. Several dynamic process-based DMS models have been developed over the last decade, and work is progressing integrating them into climate models...
Article
Full-text available
Alterations to the composition of seawater are estimated for microbial oxidation of methane from large polar clathrate destabilizations, which may arise in the coming century. Gas fluxes are taken from porous flow models of warming Arctic sediment. Plume spread parameters are then used to bracket the volume of dilution. Consumption stoichiometries...
Article
In the Arctic Ocean, both phytoplankton and sea ice algae are important contributors to the primary production and modulators of biogeochemical cycle. A global coupled ice-ocean-ecosystem model was established to investigate ice-ocean biogeochemical cycle and the ice-ocean ecosystem modules are fully coupled in the physical model POP-CICE (Parallel...
Article
Paleooceanographic evidence has been used to postulate that methane from oceanic hydrates may have had a significant role in regulating past climate. However, the behavior of contemporary oceanic methane hydrate deposits subjected to rapid temperature changes, like those now occurring in the arctic and those predicted under future climate change sc...
Article
This is a study in progress on developing sea ice and ocean ecosystem models coupled with physical models POP-CICE (Parallel Ocean Program- Los Alamos Sea Ice Model). Both the standalone CICE-ecosystem model and fully coupled POP-CICE-ecosystem model results are examined against observations, with a focus on the arctic regions. The simulated primar...
Article
As a primary photochemical constituent in upper-ocean and tropospheric geocycling, carbon monoxide is of interest to a variety of global change research communities. Dynamic three-dimensional simulations of its marine concentration patterns, emphasizing Pacific surface waters, are presented. Calculations were driven by nitrogen/iron ecodynamics wit...
Article
We are laying the foundation for an Earth System Model (ESM) focused on the sulfur cycle. This ESM will be based on the Community Climate System Model (CCSM) with a fast atmospheric chemistry & aerosol capability communicating with an ocean sulfur-cycle incorporated into the ocean biogeochemistry module. We will present a validation of the di-methy...
Article
Biogeochemical tracer bins and transformations from an established reduced sulfur cycle mechanism were introduced into the oceanic component of the Community Climate System Model. The resulting global dimethyl sulfide simulation framework was then subjected to variation in plant cell precursor content and the kinetic form of removal terms. Chi squa...
Article
Full-text available
The authors describe planetary-scale modeling of mixed-layer dimethyl sulfide (DMS) processing and distributions, conducted at a resolution of 0.288 using the Parallel Ocean Program (POP). Ecodynamic routines embedded within POP track the interactions of bacteria, multiple phytoplankton species, zooplankton, and both dissolved and detrital organics...
Article
Current global change policy debate reverberates around the polarized extremes of civilization-level cooperation through treaties as a mitigation tactic, on the one hand, and a wait-and-see approach that may lead to a climatic tragedy of the commons, on the other. Meanwhile, energy technology research is rapidly generating a perception that it will...
Article
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1] Hydrocarbon and halocarbon measurements collected during the second airborne Biomass Burning and Lightning Experiment (BIBLE-B) were subjected to a principal component analysis (PCA), to test the capability for identifying intercorrelated compounds within a large whole air data set. The BIBLE expeditions have sought to quantify and understand th...
Article
The potential for carbon dioxide (CO2) sequestration via engineered chemical sinks is investigated using a three dimensional chemical transport model (CTM). Meteorological and chemical constraints for flat or vertical systems that would absorb CO2 from the atmosphere, as well as an example chemical system of calcium hydroxide (Ca(OH)2) proposed by...
Article
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1] Asian trace gas and aerosol emissions into carbon, nitrogen, and other elemental cycles will figure prominently in near term Earth system evolution. Atmospheric hydrocarbon measurements resolve numerous chemical species and can be used to investigate sourcing for key geocarriers. A recent aircraft study of biomass burning and lightning (BIBLE A)...
Article
The geocycles of N, Fe and S in the ocean are tightly coupled and together exert strong influence on biogeochemistry of the earth system. We investigate this interaction by inserting macro-micronutrient cycling into a high resolution ocean model that realistically represents the general circulation. Simulated chlorophyll distributions reproduce man...
Article
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11 Mexico City is the world's largest and most polluted urban center. We examine the distribution of methane and other hydrocarbons within the Valley of Mexico, using it as a model for the role developing megacities will play in the next century of geochemical cycling. Seventy-five whole air samples were analyzed with multivariate statistical techn...
Article
In January/February 2002 a multi-institution, multi-platform experiment to fertilize the Southern Ocean with iron was carried out. Two areas were fertilized, one at about 55 degree S, 170 degrees W in waters that were high in nitrate and low in silicate and a second to the south at about 65 degrees S, 170 degrees W were silicate levels were also el...