Tropical Atlantic Ocean

A study in the tropical Atlantic by Williams et al. involved measuring acetone, methanol, acetonitrile and dimethyl sulfide within the atmospheric marine boundary layer and the upper ocean [116]. Measurements were taken on either side of the intertropical convergence zone. This zone, which sailors commonly refer to as the doldrums, is an area around the equator where the southeast and northeast trade winds meet. Consequently, it is a natural barrier to atmospheric mixing between the hemispheres. This results in hemispheric gradients for VOCs whose atmospheric lifetimes are shorter than interhemispheric mixing times 

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FIGURE 6.42 Fraction of HO, from each radical source as a function of altitude over the tropical Atlantic Ocean (adapted from Lee et al., 1998). 

Happell, J. D., and D. W. R. Wallace, Methyl Iodide in the Green-land/Norwegian Seas and the Tropical Atlantic Ocean Evidence for Photochemical Production, Geophys. Res. Lett., 23, 2105-2108 (1996). 

Li-Jones, X., H. B. Mating, and J. M. Prospero, Effect of Relative Humidity on Light Scattering by Mineral Dust Aerosol As Measured in the Marine Boundary Layer over the Tropical Atlantic Ocean, J. Geophys. Res., 103, 31113-31121 (1998). 

Read KA, Mahajan AS, Carpenter LJ, Evans MJ, Faria BVE, Heard DE, Hopkins JR, Lee JD, Moller SJ, Lewis AC, Mendes L, McQuaid JB, Oetjen H, Saiz-Lopez A, Pilling MJ, Plane JMC (2008) Extensive Halogen-Mediated Ozone Destruction Over the Tropical Atlantic Ocean. Nature 453 1232... 

Leboulanger, C., L. Oriol, H. Jupin, and C. Descolas-Gros. 1997. Diel variability of glycolate in the eastern tropical Atlantic Ocean. Deep-Sea Research 144 2131-2139. 

The vertical profile of DMS in marine air was first determined by Ferek et al (12), over the tropical Atlantic ocean. They found that under stable meteorological conditions, the mixing depth of DMS was about 1 km, with a rapid decline in concentration above this altitude. This distribution was considered consistent with the chemical lifetime of a few days predicted by... 

The Caribbean transects data shown by Saltzman and Cooper ( ) was obtained in oceanic air with easterly winds which should be representative of the subtropical/tropical Atlantic Ocean. On this cruise two filters were used in series, and correction was made for the OCS artifact 130). The resultant data showed H2S concentrations averaging less than 10 ppt with a slight daytime minimum, as expected for a species such as HiS which should be removed predominantly by photochemically produced OH. The maximum/minimum concentration ratio is 1.7, which is similar to that observed for DMS on the same cruise. However, it should be noted that this diurnal variation is only a few ppt, which is close to the precision of the method. We wish to stress that considerably more data is needed to verify this observation, as the data used are compiled from measurements over a considerable geographic range and because the variations involved are small. 

Philander, S. G. H., and R, C. Pacanowski. 1986. The mass and heat budget in a model of the tropical Atlantic Ocean." Journal of Geophysical Research 91 14212-14220. 

Herbland, A., and Voituriez, B. (1979). Hydrological structure analysis for estimating primary production in the tropical Atlantic Ocean. /. Mar. R s. 37, 87—101. 

Oudot, C., Andrie, C., and Montel, Y. (1990). Nitrous oxide production in the tropical Atlantic Ocean. Deep-Sea Res. 37, 183—202. 

Goering, J. J., Dugdale, R. C., andMenzel, D. (1966). Estimates of in situ rates of nitrogen uptake by Trichodesmium sp. in the tropical Atlantic Ocean. Limnol. Oceanogr. 11, 614—620. 

Langlois, R. J., LaRoche, J., and Raab, P. A. (2005). Diazotrophic Diversity and Distribution in the Tropical and Sub-tropical Atlantic Ocean. Appl. Environ. Microbiol. 71, 7910-7919. 

Carpenter, E. J., Montoya,., Burns,., Mulholland, M., Subramaniam, A., and Capone, D. (1999). Extensive bloom of a N2-fixing symbiotic association in the tropical Atlantic Ocean. Mar. Ecol. Prog. Ser. 185, 273-283. 

Le Borgne, R. (1982a). Zooplankton production in the eastern tropical Atlantic Ocean Net growth efficiency and P B in terms of carbon, nitrogen and phosphorus. Limnol. Oceanogr. 11, 681-698. 

Smethie W. M., Takahashi T., and Chipman D. W. (1985) Gas exchange and CO2 flux in the tropical Atlantic Ocean determined from Rn-222 and pC02 measurements. J. Geophys. Res. 90,1005-7022. 

Ruhlemann C., Mulitza S., Muller P. J., Wefer G., and Zahn R. (1999) Warming of the tropical Atlantic Ocean and slowdown of thermohaline circulation during the last deglaciation. Nature 402, 511-514. 

Tachikawa K., Jeandel C., and Dupre B. (1997) Distribution of rare earth elements and neodymium isotopes in settling particulate material of the tropical Atlantic Ocean (EUMELl site). Deep-Sea Res. I Oceanogr. Res. Pap. 44(11), 1769-1792. 

Jahnke R. A., Emerson S. R., Reimers C. E., Schuffert J., Ruttenberg K., and Archer D. (1989) Benthic recycling of biogenic debris in the eastern tropical Atlantic Ocean. Geochim. Cosmochim. Acta 53, 2947-2960. 

Hofmann P., Wagner T., and Beckmann B. (2003) Millennial-to centennial-scale record of African climate variability and organic carbon accumulation in the Coniacian-Santonian eastern tropical Atlantic (Ocean Drilling Program Site 959, off Ivory Coast and Ghana). Geology 31, 135-138. 

P. Boelen, M.K. de Boer, G.W. Kraay, M.J.W. Veldhuis, A.G.J. Buma (2000). UVBR induced DNA damage in natural marine picoplankton assemblages in the tropical Atlantic Ocean. Mar. Ecol. Progr. Ser., 193,1-9. 

Yashnov, V.A., 1962. Plankton of the tropical Atlantic Ocean. Tr. Morsk. Gidrofiz. Inst. Akad. Nauk S.S.S.R., 25 195—207 (in Russian). 

Furthermore, in the RHaMBLe campaign in 2007 at Cape Verde in the tropical Atlantic Ocean, lO and BrO has been measured by DOAS together with HO2. The calculation by MCM model based on these observed values agrees well with observed values within the measurement error of 20 % when halogen chemistry and heterogeneous loss process of HO2 with y(H02) = 0.1 are taken into account... 

Mahajan, A.S., Plane, J.M.C., Oetjen, H., Mendes, L., Saunders, R.W., Saiz-Lopez, A., Jones, C. E., Carpenter, L.J., McFiggans, G.B. Measurement and modelling of tropospheric reactive halogen species over the tropical Atlantic Ocean. Atmos. Chem. Phys. 10, 4611 624 (2010) Malkin, T.L., Goddard, A., Heard, D.E., Seakins, P.W. Measurements of OH and HO2 yields from the gas phase ozonolysis of isoprene. Atmos. Chem. Phys. 10, 1441-1459 (2010)... 

Sommariva, R., von Glasow, R. Multiphase halogen chemistry in the tropical Atlantic ocean. Environ. Sci. Technol. 46, 10429-10437 (2012)... 

Dasyatis marmorata, Rhinobatos cemiculus, and Rhinoptera marginata) from the east tropical Atlantic Ocean. J. Agric. Food Chem., 51, 1942-1947. 

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