Frank Millero
University of Miami, Ocean Sciences, Faculty Member
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Large quantities of African dust are carried across the North Atlantic by Trade Winds every summer. The deposition of this dust has an impact on biogeochemical processes in the Tropical and Western Atlantic Ocean and Caribbean and it... more
Large quantities of African dust are carried across the North Atlantic by Trade Winds every summer. The deposition of this dust has an impact on biogeochemical processes in the Tropical and Western Atlantic Ocean and Caribbean and it contributes to the formation of soils on Caribbean islands, the Bahamas, and the southeastern US. Here we report on a study of the temporal and spatial variability of the elemental composition of aerosol samples collected in the Trade Winds at Barbados and Miami over the summers of 2003 and 2004. Our objective is to identify characteristics that might serve as a useful tool to identify natural and anthropogenic sources of specific elements or element classes placing a special focus on dust-linked species. To this end we measured a large suite of elements: Al, Zn. Most elements exhibited a surprising uniformity that is highly correlated with dust concentration as determined by aerosol filter ash residues and by Mn concentration, shown to be an excellent proxy for dust. The concentrations of most elements are very close to average upper crustal abundances. We measured the greatest enrichments and the largest variability for As, Cd, Cu, Cr, Ni, Pb, V, and Zn, elements known to have major anthropogenic sources. For some elements, most notably the Lanthanides, we found statistically significant differences between high-dust-load samples and low-load samples and also between individual dust peaks. However, the absolute differences were generally quite small. Consequently we feel that on a sample-by-sample basis the elemental composition of dust is unlikely to serve as useful indicator of source regions with the possible exception of the Lanthanides. The uniformity of dust composition suggests that a major fraction of the dust is either derived from regions having similar composition or from multiple different sources followed by mixing during transport.
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ABSTRACT The isothermal compressibility of artificial seawater has been measured by a piezometric technique from intervals and from 0 to 40°C in 5° intervals. The measurements were made at 17 bar increments to 34 bars and the data... more
ABSTRACT The isothermal compressibility of artificial seawater has been measured by a piezometric technique from intervals and from 0 to 40°C in 5° intervals. The measurements were made at 17 bar increments to 34 bars and the data extrapolated to one atmosphere. Compressibility determinations on a Copenhagen seawater sample (∼35‰S) over the same temperature and pressure range yielded results that agreed with the artificial seawater results (within our experimental error of ±0·05 × 10−6 bar−1). The isothermal compressibility results at one atmosphere and 35‰ are in excellent agreement with the values calculated from Wilson's (1960) sound velocity data; however, our results disagree with the P-V-T data of Ekman (1908), Newton and Kennedy (1965) and Wilson and Bradley (1968). The normalized compressibilities of Ekman show excellent agreement with Wilson's and our results. A theoretical equation for the compressibility of seawater as a function of chlorinity has been developed in terms of the apparent equivalent compressibility of the major ionic components of seawater. The theoretically calculated isothermal compressibilities of seawater at 25° agree very well with the experimental results (to within ±0·09 × 10−6 bar−1).
The primary goal of the CLIVAR/CO2 Repeat Hydrography Program is to quantify the ocean's role in sequestering anthropogenic CO2 and the effects of natural variability and climate change on marine ecosystems and biogeochemistry. The... more
The primary goal of the CLIVAR/CO2 Repeat Hydrography Program is to quantify the ocean's role in sequestering anthropogenic CO2 and the effects of natural variability and climate change on marine ecosystems and biogeochemistry. The Pacific Ocean plays a unique role in the ocean carbon cycle because it is the final destination of deep waters containing high levels of preformed nutrients and dissolved inorganic carbon (DIC) and because of the way that Pacific circulation affects the transport and storage of anthropogenic CO2. Discrete high-quality DIC and total alkalinity data were acquired as part of the WOCE/JGOFS global CO2 survey cruises in the early 1990s. Hydrographic survey cruises conducted as part of the CLIVAR/CO2 Repeat Hydrography Program recently reoccupied the east-west P2 line along 30°N in 2004 and the north-south P16 line along 152°W in 2005 and 2006. DIC increases since WOCE/JGOFS were about 10-15 mumol kg-1 in shallow waters along these lines, but not all of the...
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Measurements of (p,ρ,T) properties of seawater with absolute salinity SA=(31.684, 33.507, 37.372, 37.969, 40.164, 41.825, 44.811, 46.119, 48.600, 50.232, 52.449 and 55.529) g kg−1, temperature T=273.15–468.15 K and pressures, p, up to 140... more
Measurements of (p,ρ,T) properties of seawater with absolute salinity SA=(31.684, 33.507, 37.372, 37.969, 40.164, 41.825, 44.811, 46.119, 48.600, 50.232, 52.449 and 55.529) g kg−1, temperature T=273.15–468.15 K and pressures, p, up to 140 MPa are reported with the reproducibility of the density measurements observed to be in the average percent deviation range Δρ/ρ=±0.01–0.03%. The measurements are made with a new set up vibration-tube densimeter which is calibrated using double-distilled water (Wagner and Pruß, 2002), methanol [(de Reuck and Craven, 1993), (Osada et al., 1999) and (Yokoyama and Uematsu, 2003)] and aqueous NaCl solutions [(Archer, 1992) and (Hilbert, 1979)]. Based on these measurements, an empirical expression for the density of seawater at high salinities has been developed as a function of salinity, pressure and temperature. The results can be used to extend the present equation of state of seawater to higher temperatures for pressure up to 140 MPa.
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An important property of aqueous solutions is pH because it affects chemical and biochemical properties such as chemical reactions, equilibrium conditions, and biological toxicity. With the increasing uptake of fossil fuel CO2 into the... more
An important property of aqueous solutions is pH because it affects chemical and biochemical properties such as chemical reactions, equilibrium conditions, and biological toxicity. With the increasing uptake of fossil fuel CO2 into the oceans, a decrease in pH is important to consider at this time. Unfortunately, many different methods for assessing pH have been used by different groups. The objectives of this review were to (1) briefly examine the concept of pH as it was introduced and developed, up to the current scientific developments, assumptions, and recommendations, (2) critically assess the various approaches that different scientific groups have adopted for pH, balancing their preferences and arguments, (3) compare measuring vs. modeling pH, and (4) issue recommendations on an optimized approach or approaches for pH. The main conclusions of this review are: (1) pH definitions and conventions are highly variable, which leads to highly variable estimates of pH. For example, f...
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The SCOR/IAPSO Working Group 127 on the “Equation of State and Thermodynamics of Seawater” is charged with providing improved algorithms and descriptions of the thermodynamic properties of seawater. The working group has made significant... more
The SCOR/IAPSO Working Group 127 on the “Equation of State and Thermodynamics of Seawater” is charged with providing improved algorithms and descriptions of the thermodynamic properties of seawater. The working group has made significant progress on many of its goals, and it is now time to seek the advice of the oceanographic community regarding the best practical ways of adopting these developments into oceanographic practice. The Working Group has met twice to date, once in Warnemünde in 2006, then in Reggio Calabria in 2007. Our next meeting is in Berlin in September 2008. The working group will soon provide the most accurate algorithms to date for the thermodynamic properties of seawater (such as density, entropy, enthalpy, specific heat capacity, etc). In order to achieve such accuracy it became evident that a salinity variable is required that more accurately represents absolute salinity than does the conductivity-based Practical Salinity. Spatial variations in the composition...
The practical (Sp) and reference (SR) salinities do not account for variations in physical properties such as density and enthalpy. Trace and minor components of seawater, such as nutrients or inorganic carbon affect these properties.... more
The practical (Sp) and reference (SR) salinities do not account for variations in physical properties such as density and enthalpy. Trace and minor components of seawater, such as nutrients or inorganic carbon affect these properties. This limitation has been recognized and several studies have been made to estimate the effect of these compositional changes on the conductivity-density relationship. These studies have been limited in number and geographic scope. Here, we combine the measurements of previous studies with new measurements for a total of 2,857 conductivity-density measurements, covering all of the world’s major oceans, to derive empirical equations for the effect of silica and total alkalinity on the density and absolute salinity of the global oceans and to recommend an equation applicable to most of the World’s oceans. The potential impact on salinity as a result of uptake of anthropogenic CO2 is also discussed.
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... Hlgher Order Electrostatic Terms Rabindra N. Roy,* Susan A. Rice, Kathleen M. Vogel, Lakshmi N. Roy, Department of Chemistry, Drury College, Springfield. Missouri 65802 and Frank J. Millero ... SOC. 1961,83, 2636. (2) Rush, RM;... more
... Hlgher Order Electrostatic Terms Rabindra N. Roy,* Susan A. Rice, Kathleen M. Vogel, Lakshmi N. Roy, Department of Chemistry, Drury College, Springfield. Missouri 65802 and Frank J. Millero ... SOC. 1961,83, 2636. (2) Rush, RM; Johnson, J. S. J. Phys. Chem. 1968, 72, 767. ...
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Measurements were made of adsorption of a periphytic marine bacterium, glucose, and glutamic acid to inorganic particles in seawater and defined bacterial growth medium. Measurements of the metabolism of bacteria were made in the presence... more
Measurements were made of adsorption of a periphytic marine bacterium, glucose, and glutamic acid to inorganic particles in seawater and defined bacterial growth medium. Measurements of the metabolism of bacteria were made in the presence and absence of particles by microcalorimetry and radiorespirometry. It was found that hydroxyapatite adsorbs glutamic acid, but not glucose, from the experimental medium. It was also found that hydroxyapatite adsorbs essentially all of the bacteria from the medium when the bacterial concentration is approximately 6 x 10 bacteria per ml. If the bacterial concentration is approximately 6 x 10, then only a small fraction of cells become attached. It was therefore possible to select bacterial concentrations and organic nutrients so that bacterial attachment, organic nutrient adsorption, or both would occur in different experiments. In this experimental system the metabolism by attached and nonattached bacteria of adsorbing and nonadsorbing organic nutr...
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Microcalorimetric measurements of heat production from glucose by Vibrio alginolyticus were made to assess the viability of calorimetry as a technique for studying the metabolism of marine bacteria at organic nutrient concentrations found... more
Microcalorimetric measurements of heat production from glucose by Vibrio alginolyticus were made to assess the viability of calorimetry as a technique for studying the metabolism of marine bacteria at organic nutrient concentrations found in marine waters. The results show that the metabolism of glucose by this bacterium can be measured by calorimetry at submicromolar concentrations. A linear correlation between glucose concentration and total heat production was observed over a concentration range of 8 mM to 0.35 muM. It is suggested that these data indicate a constant efficiency of metabolism for this bacterium over the wide range of glucose concentrations studied.
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The effect of electrolyte concentration on attachment of Vibrio alginolyticus to hydroxyapatite was determined. Bacterial affinity for attachment to the surface and surface capacity were derived from linearization of bacterial adsorption... more
The effect of electrolyte concentration on attachment of Vibrio alginolyticus to hydroxyapatite was determined. Bacterial affinity for attachment to the surface and surface capacity were derived from linearization of bacterial adsorption isotherms. At low concentrations (<0.1 M) the affinity of the bacteria for the surface increased with increasing ionic strength, in agreement with the D.L.V.O. theory of colloid interaction. At higher concentrations, bacterial affinity for the surface decreased with increasing concentration of cations and was not related to ionic strength changes in the medium. These results demonstrate a change in the mechanism by which salts affect bacterial attachment at salt concentrations above 0.1 M. The results are consistent with the relationship between the proportion of attached bacteria and salinity observed in previously published field studies. The results may also resolve differences between various attachment studies carried out in different ionic ...
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Density measurements have been made on aqueous lysozyme solutions at 20, 25, and 30 degrees. The apparent specific volumes, phi v, and expansibilities, phi e, have been determined from the density measurements and fitted to a function of... more
Density measurements have been made on aqueous lysozyme solutions at 20, 25, and 30 degrees. The apparent specific volumes, phi v, and expansibilities, phi e, have been determined from the density measurements and fitted to a function of concentration (weight per cent). Sound velocities and heat capacities have also been measured for various concentrations of lysozyme-water solutions at 25 degrees. From the density, expansibility, heat capacity, and sound velocity data at 25 degrees, the isothermal compressibility, phi k, for the lysozyme solutions have been calculated over a range of concentrations. All the physicochemical properties measured were found to be a linear function of the weight per cent of lysozyme. The number of water molecules hydrated to 1 mol of lysozyme was estimated from the volume and compressibility and found to be 162 at 25 degrees.
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... cm-3 with a &quot;vibrating tube&quot; flow densimeter described by Picker, Tremblay, and Joli~oeur.~&#x27; The ... 3 X and f1.8 X cm3 mol-&#x27; bar-&#x27; in c ~ I ~ ( ~ ) , respectively, for mT = 0.05 and ...... more
... cm-3 with a &quot;vibrating tube&quot; flow densimeter described by Picker, Tremblay, and Joli~oeur.~&#x27; The ... 3 X and f1.8 X cm3 mol-&#x27; bar-&#x27; in c ~ I ~ ( ~ ) , respectively, for mT = 0.05 and ... Evaporation of the Na2HP04 stock solution and subsequent ignition to Na4P207 gave ana-lytical results ...
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The Physical Chemistry of Natural Waters
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Both carbon system measurements and derived products can be used in ocean circulation studies to infer water mass transport. In this paper we give a brief overview of the global CO2 survey effort; then we give a few examples of how carbon... more
Both carbon system measurements and derived products can be used in ocean circulation studies to infer water mass transport. In this paper we give a brief overview of the global CO2 survey effort; then we give a few examples of how carbon data can be used to examine ocean transport. Finally, we discuss the estimates of anthropogenic CO2 from the global survey and the relation between anthropogenic tracers and ocean circulation. In the 1990s, several programs, including the Joint Global Ocean Flux Study (JGOFS), the World Ocean Circulation Experiment (WOCE), and NOAA's Ocean-Atmosphere Carbon Exchange Study (OACES), conducted major field campaigns that included water column measurements of at least two inorganic carbon parameters in the major ocean basins. Working with international investigators, we have been striving to synthesize these data into a unified consistent data set. The synthesis effort began with the Indian Ocean (IO). The IO survey marked the culmination of the gl...
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ABSTRACT An automated sampling and analysis system was developed to determine the total inorganic carbon (TCO2) in seawater. Measurements are performed on subsamples taken from the shipboard flowing seawater line. The flowing TCO2 system... more
ABSTRACT An automated sampling and analysis system was developed to determine the total inorganic carbon (TCO2) in seawater. Measurements are performed on subsamples taken from the shipboard flowing seawater line. The flowing TCO2 system (FTCO2) automatically acidifies and strips the CO2 out of a known volume of sea water and determines the concentration by integrating the infra red (IR) absorbance. Laboratory results have demonstrated an analytical precision of 2–5 μM in TCO2 for this system. Intercomparison of TCO2 measurements with the FTCO2 system and the SOMMA (single operator multimetabolic analyzer) agreed within their respective uncertainties. The TCO2 in surface seawater was determined continually on the flowing seawater line aboard the R/V Thompson in the Arabian Sea. The average difference between the TCO2 determined on surface seawater with the flowing system and the SOMMA was 6.5±8.7 μM. Measurements made with the flowing system on CRMs agreed to ±3 μM with the assigned value. TCO2 in surface waters in the Arabian Sea varied by as much as 40 μM on short spatial and temporal scales. Although the accuracy of the present design of the FTCO2 system is not as good as the SOMMA, the surface TCO2 variability with time and space is captured with the FTCO2 system and is completely missed by discrete measurements made on CTD casts. Continual measurements of TCO2 will be valuable in characterizing the temporal and spatial changes in the carbon dioxide system in surface ocean waters.
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The stoichiometric dissociation constant, pK*, of TRISH+ has been determined from emf measurements in NaClO4 solutions to 6.0m at 25°C. The results have been used to derive Pitzer coefficients for the interaction of TRISH+ with ClO4-. The... more
The stoichiometric dissociation constant, pK*, of TRISH+ has been determined from emf measurements in NaClO4 solutions to 6.0m at 25°C. The results have been used to derive Pitzer coefficients for the interaction of TRISH+ with ClO4-. The coefficients have been compared to the values in NaCl solutions. The values of pK* for TRISH+ can be used to calibrate pH electrodes