Atmospheric flux

Fluxes are linear functions of reservoir contents. Reservoir size and the residence time of the carbon in the reservoir are the parameters used in the functions. Between the ocean and the atmosphere and within the ocean, fluxes rates are calculated theoretically using size of the reservoir, surface area of contact between reservoirs, concentration of CO2, partial pressures of CO2, temperature, and solubility as factors. The flux of carbon into the vegetation reservoir is a function of the size of the carbon pool and a fertilization effect of increased CO2 concentration in the atmosphere. Flux from vegetation into the atmosphere is a function of respiration rates estimated by Whittaker and Likens (79) and the decomposition of short-lived organic matter which was assumed to be half of the gross assimilation or equal to the amount transferred to dead organic matter. Carbon in organic matter that decomposes slowly is transferred... 

CO2 ) The ocean to atmosphere flux, which is dependent on the concentration of the dissolved species C02(aq), is related to the total carbon content in the surface layer (Ms) by... 

Atmospheric fluxes of lead in the United States rose steadily from the first decades of this century, reaching a maximum in the early 1970s (see Eisenrich et al., 1986 and references therein). Passage of the Clean Air Act of 1972 and its subsequent amendments resulted in dramatic reductions in atmospheric lead concentrations, although lead fluxes worldwide still remain 10-1000 times background levels (Settle et al, 1982 Settle and Patterson, 1982). 

Sanchez-Cabeza JA, Masque P, Martinez-Alonso M, Mir J, Esteve I (1999) Pb-210 atmospheric flux and growth rates of a microbial mat from the northwestern Mediterranean Sea (Ebro River Delta). Environ Sci Technol 33 3711-3715... 

Annual composite surface ocean-atmosphere difference in partial pressure of NgO (in natm = 10 atm). Positive values reflect ocean to atmosphere fluxes. Source After Nevison, C. D., et al. (1995). Journal of Geophysical Research 100, 15809-15820. (See companion website for color version.)... 

Pio, C. A., and A. A. Valente, Atmospheric Fluxes and Concentrations of Monoterpenes in Resin-Tapped Pine Forests, Atmos. Enriron., 32, 683-691 (1998). 

Clough, S. A., M. J. Iacono, and J. L. Moncet, Line-by-Line Calculations of Atmospheric Fluxes and Cooling Rates Application to Water Vapor, J. Geophys. Res., 97, 15761-15785 (1992). 

Somewhat similar levels in air, between 0.5 and 5 ng/m (mean, 2 ng/m ) of di(2-ethylhexyl) phthalate have been found in the Great Lakes ecosystem (Canada and United States). The concentration of di(2-ethylhexyl) phthalate in precipitation ranged from 4 to 10 ng/L (mean, 6 ng/L). Atmospheric fluxes to the Great Lakes are a combination of dry and wet removal processes. The total deposition of di(2-ethylhexyl) phthalate into Lakes Superior, Michigan, Huron, Erie and Ontario was estimated to amount to 16, 11, 12, 5.0 and 3.7 tonnes per year, respectively (Eisenreich et al., 1981). 

Note The consistent tendency of BF to show seawater-to-atmosphere fluxes has been interpreted as evidence for a natural source of bromoform in the sea. 

Other Applications of the Multiple-Core Approach. The bulk of this chapter has dealt with the specific application of multiple-core methodology to questions of atmospheric Hg deposition. Whole-basin Hg accumulation rates for seven lakes, calculated from multiple sediment cores, were used in a simple mass-balance model to estimate atmospheric fluxes and Hg transport from catchment soils. This approach can be used to answer other limnological questions, and the model is not restricted to Hg or atmospheric deposition. 

The only current-use OC pesticide tracked by IADN, other than lindane, is endosulfan. Endosulfan is currently used at approximately 25 000 kg/year in Ontario alone in the mid-1990s [53]. It has a variety of uses in the Great Lakes region, but its heaviest application is in the southern USA, on cotton. In 1997-1998, total atmospheric fluxes of a-endosulfan were highest in Lakes Erie and Ontario, in the range of 27-34 ng/m2/day, whereas values for remote Lake Superior were in the range of 1.7-2.5 ng/m2/day. Insufficient data were collected to allow estimates for Lakes Michigan and Huron, or for all lakes for endosulfan sulfate. 

A summary of toxaphene atmospheric flux estimates to the Great Lakes is given in Table 8. The reported fluxes for a particular lake in Table 8 differ considerably in magnitude and sometimes even in direction. Seasonal changes in flux direction are due to variations in water temperature (influencing the Henry s law constant) and air concentration. Changes in flux magnitude are driven by air concentration and by wind speed, which affects the air-water mass transfer coefficients. 

Atmospheric diffuse dust emissions constitute a pollution source, which is difficult to be quantified. In fact, a diffuse emission is defined as a polluting atmospheric flux which is spread out over a large area or which is not concentrated [1]. In the case of steelwork sites, diffuse dust emissions can represent many as 20% of airborne particle pollution, they result from conveyances and handling of materials and from wind erosion of exposed aggregate storage piles. This latter category of emission source is widely predominant. 

Charlock T.P. Rose F.G. Rutan D.A. Alberta T.L. Kratz D.P. Coleman L.H. Smith G.L. Manalo-Smith N. and Bess T.D. (1997). Compute Surface and Atmospheric Fluxes (System 5.0). CERES Algorithm Theoretical Basis Document, CERES Publ., Hampton, VA, 84 pp. 

To complete the overview on sulfur emissions, a brief discussion of methods used to estimate emissions is appropriate. There are primarily two methods that may be used to measure earth-atmosphere flux of gases. In the dynamic chamber method, an open-bottom chamber is placed over a surface of interest such as mud, soil, or water, with or without vegetation, to capture the gases... 

Buat-Menard P. and Chesselet R. (1979) Variable influence of the atmospheric flux on the trace metal chemistry of oceanic suspended matter. Earth and Planet. Sci. Lett., 42, 399-411. 

Nevissi, A. (1982) Atmospheric flux of 210Pb in the northwestern United States. In Natural Environment (Vohra, K.G, Mishra, U.C., Pillai, K.C., and Sadasivan, S., eds.), pp. 614-620, John Wiley, New York. 

Raymond, P.A., Caraco, N.F., and Cole, J.J. (1997) Carbon dioxide concentration and atmospheric flux in the Hudson River. Estuaries 20, 381-390. 

More simultaneous measurements of NH3 in the ocean and in the atmosphere are needed to reduce the considerable uncertainties of the ocean/atmosphere flux estimates. The ongoing acidification of the ocean will shift the NH3/NH4 equilibrium to NH. On the one hand this might have implication for the atmospheric distribution of NH3, since the uptake capacity of the ocean will be increased with unknown consequences for chemistry of the atmosphere (e.g. the aerosol formation) over the ocean. On the other hand this might have severe implications for the nitrification rates in seawater because they are influenced by the pH. When the pH drops from 8 to 7, nitrification rates can be reduced by 50% (Huesemann et al., 2002). (One explanation for this is that the ammonia monooxygenase enzyme uses rather NH3 than NH4 as substrate.) Most recently it was suggested that atmospheric NH3 serves as a foraging cue for seabirds such as the blue petrel (Nevitt ei a/., 2006) is an excretion product of... 

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