1. Zhang, J.-Z., and C.J. Fischer. Carbon dynamics of Florida Bay: Spatiotemporal patterns and biological control. Environmental Science and Technology, 48(16):9161-9169, doi:10.1021/es500510z 2014

    Abstract:

    Carbon dynamics of Florida Bay is manifested by wide ranges of pH (7.65–8.61), dissolved inorganic carbon (DIC, 929-3223 μM), and partial pressure of CO2 (pCO2, 50-1313 μatm) observed over seven years. Despite the seasonal variation, a decline of −0.0066 pH per year was observed as a result of ocean acidification, and the spatiotemporal patterns were consistent with known biological processes in the bay. Microbial respiration of organic matter produced high pCO2, resulting in Florida Bay being a CO2 source to the atmosphere during winter and spring. In summer, cyanobacteria blooms developed in the north central bay drew down pCO2, causing bloom waters to become a CO2 sink while the nonbloom waters shrunk but remained a CO2 source. The maxima local CO2 fluxes were 36.4 ± 10.5 and −14.0 ± 5.6 mmol m–2 d–1 for the source and sink region, respectively. Cyanobacteria blooms modulated the interannual variation in bay-wide CO2 net flux, which averaged 7.96 × 109 ± 1.84 × 109 mol yr–1. Extensive cyanobacteria blooms in 2009 resulted in a 50% reduction in the net CO2 flux as compared with 2010 when a minimal cyanobacteria bloom occurred.

  2. Carsey, T.P., S.J. Stamates, N. Amornthammarong, J.R. Bishop, F. Bloetscher, C.J. Brown, J.F. Craynock, S.R. Cummings, W.P. Dammann, J. Davis, C.M. Featherstone, C.J. Fischer, K.D. Goodwin, D.E. Meeroff, J.R. Proni, C.D. Sinigalliano, P.K. Swart, and J.-Z. Zhang. Boynton Inlet 48-hour sampling intensives: June and September 2007. NOAA Technical Report, OAR-AOML-40, 43 pp., 2012

    Abstract:

    Researchers with the Ocean Chemistry Division of NOAA’s Atlantic Oceanographic and Meteorological Laboratory performed two 48-hour intensive studies of the water flowing through the Boynton Inlet at Boynton Beach, Florida, during June and September 2007. These studies were conducted in support of the Florida Area Coastal Environment (FACE) program. Academic partners who also participated in the effort included colleagues with the University of Miami’s Cooperative Institute for Marine and Atmospheric Studies and the Rosenstiel School of Marine and Atmospheric Science, Florida Atlantic University’s Laboratories for Engineered Environmental Solutions, and the Applied Research Center of Florida International University. Sampling was performed from the southern boardwalk at Boynton Beach during the June intensive and the Boynton Beach Inlet Bridge during the September intensive. The sampling strategy was designed to collect water samples over four complete tidal cycles for each intensive; these data would be employed to quantify the total flux of nearshore-source entities into the coastal waters. The first sampling event was conducted on June 4-6, 2007, and the second was conducted on September 26-28, 2007. Data collected include nutrients (silicate, orthophosphate, ammonium, nitrite+nitrate), isotope ratios of nitrogen, the presence or absence of selected biological indicators (Escherichia coli, enterococci, and total coliform), and physical parameters that included pH, salinity, total suspended solids, and turbidity. Critical to this study was the continuous in situ flow rate measurements obtained via an acoustic Doppler current profiler (ADCP) mounted on the north side of the inlet. This report presents the data gathered from the two sampling intensives. The data reported herein suggest that inlets are important contributors of nutrient and microbiological loads to the coastal zone. The overall view presented is that the lagoon input into Boynton Inlet may be substantial but is also highly variable.

  3. Carsey, T.P., H. Casanova, C. Drayer, C. Featherstone, C. Fischer, K. Goodwin, J. Proni, A. Saied, C. Sinigalliano, J. Stamates, P. Swart, and J.-Z. Zhang. FACE outfalls survey cruise: October 6-19, 2006. NOAA Technical Report, OAR-AOML-38, 130 pp. (CD-ROM), 2010

    Abstract:

    In October 2006, a cruise of the Florida Area Coastal Environment (FACE) program was conducted aboard the NOAA RV Nancy Foster. The cruise visited coastal sites in the vicinity of six treated wastewater boils in south Florida. The outfalls included in this study were those for the South Central, Boca Raton, Broward, Hollywood, Miami-Dade North, and Miami-Dade Central wastewater treatment plants. The boils and associated down-current plumes were studied to produce a data set of ocean currents, ocean chemistry, and microbiology. Seawater was analyzed for nitrate + nitrite, nitrite, ammonia, orthophosphate, and silicate. Samples down-current of each boil were collected by a conductivity-temperature-depth (CTD) rosette at three depths--near-surface, mid-depth, and near-bottom--and from three transects--inshore of the boil, approximately in line with the boil, and further offshore of the boil. Overall, surface samples showed the highest nutrient concentrations versus samples taken at other depths; surface samples taken nearest the boil showed the highest nutrient concentrations in comparison to other samples collected in the vicinity of the outfall. The only exception was Si, which had a maximum observed concentration at an inlet sampling site. The outfall plume was found to be dynamic, irregular, and mainly in the upper 10 m of the water column. Samples were analyzed for a variety of microbes; the detection frequency was higher for the southern boils compared to the northern boils. The CTD data indicated a tendency toward better defined and deeper thermoclines at the 20-30 m depth in the deeper (more offshore) casts; the thermocline showed a tendency to shoal at 10-20 m and become less well defined in more inshore casts.

  4. Zhang, J.-Z., L. Guo, and C.J. Fischer. Abundance and chemical speciation of phosphorus in sediments of the Mackenzie River Delta, the Chukchi Sea, and the Bering Sea: Importance of detrital apatite. Aquatic Geochemistry, 16(3):353-371, doi:10.1007/s10498-009-9081-4 2010

    Abstract:

    Utilizing a sequential extraction technique this study provides the first quantitative analysis on the abundance of sedimentary phosphorus and its partitioning between chemically distinguishable phases in sediments of the Bering Sea, the Chukchi Sea and the Mackenzie River Delta in the western Arctic Ocean. Total sedimentary phosphorus (TSP) was fractionated into five operationally defined phases: (1) adsorbed inorganic and exchangeable organic phosphorus; (2) Fe-bound inorganic phosphorus; (3) authigenic carbonate fluorapatite, biogenic apatite, and calcium carbonate-bound inorganic and organic phosphorus; (4) detrital apatite; and (5) refractory organic phosphorus. TSP concentrations in surface sediments increased from the Chukchi Sea (18 µmol g-1 of dried sediments) to the Bering Sea (22 µmol g-1) and to the Mackenzie River Delta (29 µmol g-1). Among the five pools, detrital apatite phosphorus of igneous or metamorphic origin represents the largest fraction (~43%) of TSP. The second largest pool is the authigenic carbonate fluorapatite, biogenic apatite as well as CaCO3 associated phosphorus (~24% of TSP), followed by the Fe-bound inorganic phosphorus, representing ~20% of TSP. The refractory organic P accounts for ~10% of TSP and the readily exchangeable adsorbed P accounts for only 3.5% of TSP. Inorganic phosphorus dominates all of phosphorus pools, accounting for an average of 87% of the TSP. Relatively high sedimentary organic carbon and total nitrogen contents and low delta13C values in the Mackenzie River Delta together with the dominance of detrital apatite in the TSP demonstrate the importance of riverine inputs in governing the abundance and speciation of sedimentary phosphorus in the Arctic coastal sediments.

  5. Zhang, J.-Z., C.R. Kelble, C.J. Fischer, and L.D. Moore. Hurricane Katrina induced nutrient runoff from an agricultural area to coastal waters in Biscayne Bay, Florida. Estuarine, Coastal, and Shelf Science, 84(2):209-218, doi:10.1016/j.ecss.2009.06.026 2009

    Abstract: Water quality surveys conducted in Biscayne Bay, Florida, indicated enhanced nutrient input coupled with increased runoff as a result of precipitation associated with Hurricane Katrina. Nutrient concentrations before Katrina ranged from 0.06-24.2 mM (mean 3.3 mM) for nitrate and 0.01-0.18 mM (mean 0.1 mM) for soluble reactive phosphate. Five days after Katrina, nitrate concentrations ranged from 0.87-80.0 mM (mean 17.0 mM), with a bay-wide mean increase of 5.2-fold over pre-hurricane levels. Soluble reactive phosphate concentrations ranged from 0.07-0.62 mM (mean 0.2 mM), with a bay-wide mean increase of 2-fold over pre-hurricane levels. The maximum concentrations for both nitrate and soluble reactive phosphate were found at a water quality monitoring station near the mouth of Mowry Canal, which drains an agricultural area in the southern Biscayne Bay watershed near Homestead, Florida. At this station, nitrate and soluble reactive phosphate concentrations increased 7- and 10-fold, respectively. Storm-induced fertilizer runoff from this agricultural area caused a bay-wide increase in nutrient concentrations after Hurricane Katrina. Nutrient concentrations in the bay returned to pre-hurricane levels within three months after Hurricane Katrina, showing the resiliency of the Biscayne Bay ecosystem.

  6. Zhang, J.-Z., and C.J. Fischer. A simplified resorcinol method for direct spectrophotometric determination of nitrate in seawater. Marine Chemistry, 99(1-4):220-226, doi:10.1016/j.marchem.2005.09.008 2006

    Abstract:

    A direct, spectrophotometric method has been adapted for quantitative determination of nitrate concentrations in seawater. The method is based on nitration of resorcinol in acidified seawater, resulting in a color product. The absorption spectrum obtained for the reaction product shows a maximum absorption at 505 nm, with a molar absorptivity of 1.7 x 104 L mol-1 cm-1. This method has a detection limit of 0.5 µM and is linear up to 400 µM for nitrate. The advantage of this method is that all reagents are in aqueous solutions without involving cadmium granules as a heterogeneous reactant, as in conventional methods, and therefore is simple to implement. Application of the resorcinol to seawater analysis demonstrated that the results obtained are in good agreement with the conventional approach involving the reduction of nitrate by cadmium followed by diazotization.

  7. Zhang, J.-Z., C.J. Fischer, and P.B. Ortner. Potential availability of sedimentary phosphorus to sediment resuspension in Florida Bay. Global Biogeochemical Cycles, 18(4):GB4008, 14 pp., doi:10.1029/2004GB002255 2004

    Abstract:

    Several studies have suggested that phosphorus is a limiting nutrient for seagrass and phytoplankton growth in much of Florida Bay. In fact, soluble reactive phosphate concentrations in Florida Bay waters can be as low as a few nM. Sediments represent the largest phosphorus reservoir because Florida Bay sediments are dominated by carbonate, which has a strong capacity to retain phosphorus. The supply of phosphorus to the water column from sediment resuspension is potentially important in providing the nutrients required for phytoplankton production. Applying an improved sequential extraction technique to sediments collected from 40 geographically representative stations in Florida Bay, this study provides the first detailed spatial distribution of total sedimentary phosphorus (TSP) and its partitioning into five chemically distinguishable pools in the surface, fine-grained sediments of the bay. A strong gradient of decreasing TSP concentration was observed from the west (14.6 µmol g-1) to east (1.2 µmol g-1) across the central bay. The spatial pattern of TSP is consistent with distribution of both seagrass and phytoplankton that are limited by available phosphorus in Florida Bay. Among the five pools, the authigenic carbonate fluorapatite, biogenic apatite and CaCO3-bound phosphorus account for the largest fraction (45%) of TSP, of which inorganic phosphorus is the dominant form, and organic phosphorus accounts for about 30% in the western and north central regions and less than 10% in other areas of Florida Bay. The second largest pools are the refractory organic phosphorus (24% of TSP) and reductant-soluble inorganic phosphorus (19% of TSP). Readily exchangeable phosphorus accounts for 8% of TSP, of which organic phosphorus is 60%. Detrital apatite phosphorus of igneous or metamorphic origin represents the smallest fraction, only 5% of TSP. Spatial distribution of phosphorus and iron in sediments indicates that external sources of these two essential plant nutrients to Florida Bay are spatially separated with phosphorus introduced by west coast waters across the western margin of Florida Bay and iron from freshwater flow into the eastern region.

  8. Zhang, J.-Z., and C.J. Fischer. The role of sediment resuspension in the phosphorus cycle in Florida Bay. Proceedings, 2001 Florida Bay and Adjacent Marine Systems Science Conference, Key Largo, FL, April 23-26, 2001. University of Florida, 98-99, 2001

    Abstract:

    The mass mortality of sea grass and frequent algal blooms in Florida Bay are a result of eutrophication. Existing data indicate that phosphorus is the limiting nutrient, while nitrogen is abundant. Therefore, the supply of phosphorus is critical to the onset and persistence of phytoplankton blooms in Florida Bay. Biogenic calcium carbonates are major components of the sediments (>90%) in the Florida Bay. Our studies have shown that phosphorus is strongly adsorbed on the surface of calcium carbonate sediment. Sediments in Florida Bay can easily be suspended by storms and tidal mixing due to shallow water depth (~3 m). Phosphorus cycling processes such as release from adsorption to and coprecipitation with suspended sediment may play an important role in the supply phosphorus to phytoplankton bloom. Our project has been focused on the following three aspects: (1) The time scales of phosphate availability through sediment resuspension in Florida Bay water and kinetic of interaction of sedimentary phosphorus with seawater; (2) the distribution coefficients for phosphorus partitioning between sediment/seawater in Florida Bay; and (3) the reactivity and partitioning of various pools of sedimentary phosphorus in Florida Bay surface sediments.

  9. Zhang, J.-Z., C.J. Fischer, and P.B. Ortner. Continuous flow analysis of phosphate in natural waters using hydrazine as a reductant. International Journal of Environmental Analytical Chemistry, 80(1):61-73, doi:10.1080/03067310108044386 2001

    Abstract:

    The use of hydrazine to reduce 12-molybdophosphoric acid to phosphomolybdenum blue in continuous flow analysis of phosphate in natural water samples is characterized. Using hydrazine in gas-segmented continuous flow phosphate analysis minimizes coating and silicate interference in comparison with using ascorbic acid. The addition of Sb to the molybdate reagent increases sensitivity at temperatures greater than 50°C but causes severe additional coating. The degree of coating was found to be a function of pH. Minimal coatings were achieved at a final solution pH of 0.5. Silicate interference was found to increase dramatically with color development temperature. At room temperature no detectable silicate interference was found. We recommend hydrazine in preference to ascorbic acid for gas-segmented continuous flow phosphate analysis with optimal reaction conditions of room temperature color development and a final solution pH of 0.5.

  10. Zhang, J.-Z., C.J. Fischer, and P.B. Ortner. Comparison of open tubular cadmium reactors and packed cadmium columns in automated gas-segmented continuous flow nitrate analysis. International Journal of Environmental Analytical Chemistry, 76(2):99-113, doi:10.1080/03067310008034123 2000

    Abstract:

    Detailed procedures are provided for preparing packed cadmium columns to reduce nitrate to nitrite. Experiments demonstrated the importance of conditioning both open tubular cadmium reactor (OTCR) and packed copper-coated cadmium columns to achieve 100% reduction efficiency. The effects of segmentation bubbles in the OTCR upon reduction efficiency and baseline noise in nitrate analysis are investigated using an auto-analyzer. Metal particles derived from segmentation bubbles in OTCR result in interference with continuous flow analyses. Therefore, packed columns are recommended for determination of low level nitrate in natural waters.

  11. Zhang, J.-Z., C.J. Fischer, and P.B. Ortner. Laboratory glassware as a contaminant in silicate analysis of natural water samples. Water Research, 33(12):2879-2883, doi:10.1016/S0043-1354(98)00508-9 1999

    Abstract:

    When glassware is used for the storage of water samples, reagents, and standard solutions, dissolution of silicate from the glass containers can contaminate the samples. Experimental results demonstrate that dissolution from glassware can introduce micromolar silicate within a few hours. The extent of dissolution depends upon contact time, salinity, and pH of the solution, and the size and shape of the containers.

  12. Zhang, J.-Z., C.J. Fischer, and P.B. Ortner. Optimization of performance and minimization of silicate interference in continuous flow phosphate analysis. Talanta, 49(2):293-304, doi:10.1016/S0039-9140(98)00377-4 1999

    Abstract:

    Specific reaction conditions for automated continuous flow analysis of phosphate are optimized in regard to minimizing coating and silicate interference, while maintaining high sensitivity. Use of Sb in the reagent increases sensitivity and yields absorbances with little temperature dependence. Coating can be minimized by using a final solution at a pH >0.5. At final pH of 0.78, there is maximum interference from silicate in the sample. We recommend, therefore, as an optimal reaction condition with minimal silicate interference, the use of Sb, a final solution pH of 1.00, room temperature for the reaction, and a [H+]/Mo ratio of 70. An equation is provided to correct silicate interference in high precision phosphate determination.

  13. Carsey, T.P., D.D. Churchill, M.L. Farmer, C.J. Fischer, A.A.P. Pszenny, V.B. Ross, E.S. Saltzman, M. Springer-Young, and B. Bonsang. Nitrogen oxides and ozone production in the North Atlantic marine boundary layer. Journal of Geophysical Research, 102(D9):10,653-10,665, doi:10.1029/96JD03511 1997

    Abstract:

    Measurements of reactive nitrogen gases (NO, NO2, NOy), as well as related chemical (O3, CO, aerosol black carbon, radon, selected nonmethane hydrocarbons) and meteorological parameters, were made on board the R/V Malcolm Baldrige prior to and subsequent to the 1992 ASTEX (Atlantic Stratocumulus Transition Experiment) in the North Atlantic Ocean during June and July 1992. Results showed indications of well-defined plumes from North America and Europe from both chemistry and back trajectory data. Elevated ozone concentrations were also observed in air masses from uninhabited continental regions. Chemical and meteorological data were incorporated into a simple photochemical model in which ozone destruction predominated over generation. The principal reaction leading to ozone destruction was O(1D) + H2O - 2OH.

  14. Zhang, J.-Z., P.B. Ortner, and C.J. Fischer. Method 353.4: Determination of nitrate and nitrite in estuarine and coastal waters by gas segmented continuous flow colorimetric analysis. In Methods for the Determination of Chemical Substances in Marine and Estuarine Environmental Matrices, Second Edition. U.S. Environmental Protection Agency, EPA-600-R-97-072, 20 pp., 1997

    Abstract:

    No abstract.

  15. Zhang, J.-Z., P.B. Ortner, C.J. Fischer, and L.D. Moore. Method 349.0: Determination of ammonia in estuarine and coastal waters by gas segmented continuous flow colorimetric analysis. In Methods for the Determination of Chemical Substances in Marine and Estuarine Environmental Matrices, Second Edition. U.S. Environmental Protection Agency, EPA-600-R-97-072, 16 pp., 1997

    Abstract:

    No abstract.

  16. Carsey, T.P., M.L. Farmer, C.J. Fischer, A. Mendez, V.B. Ross, M. Springer-Young, and M.P. Zetwo. Atmospheric chemistry measurements during Leg 4, 1993 North Atlantic cruise, R/V Malcolm Baldrige. NOAA Data Report, ERL-AOML-28 (PB96-162581), 137 pp., 1996

    Abstract:

    During September 1993, AOML conducted a multi-leg cruise aboard the Malcolm Baldrige in the North Atlantic from Iceland to Miami, Florida. The objective was to evaluate the distribution and transport of tropospheric ozone and ozone precursors in the North Atlantic. The investigation was associated with the North Atlantic Regional Experiment (NARE), a component of the International Global Atmospheric Chemistry (IGAC) project. The cruise track traversed three diverse wind and chemical regimes: pristine polar westerlies, polluted westerlies, and marine southeasterlies. Along this cruise track a large suite of chemical and meteorological data were measured. These included ozone, carbon monoxide in air and surface water, NO, NO2, Noy, peroxyacetyl nitrate, SO2, non-methane hydrocarbons (NMHC), and aerosols. The measurements and instrumentation are described in this data report.

  17. Carsey, T.P., M.L. Farmer, C.J. Fischer, A. Mendez, A.A.P. Pszenny, V.B. Ross, P.-Y. Whung, M. Springer-Young, and M.P. Zetwo. Atmospheric chemistry measurements from the 1992 ASTEX/MAGE cruise, May 30-July 21, 1992 (cruise number 91-126). NOAA Data Report, ERL-AOML-26 (PB95-179552), 90 pp., 1994

    Abstract:

    The report describes the results of the 1992 ASTEX/MAGE cruise aboard the NOAA R/V Malcolm Baldrige. The cruise was designed to support research sponsored by the NOAA Climate and Global Change Program under: (1) the Marine Sulfur and Climate (MS&C) component of the Atmosphere and Land-Surface Processes Core Project, and (2) the Radiatively Important Trace Species (RITS) component of the Atmospheric Chemistry Core Project. Chemical and meteorological measurements obtained on the cruise include reduced sulfur gases, ozone, carbon monoxide, nitrogen oxides and peroxyacetyl nitrate, rawinsondes, aerosol chemistry, microwave radiometry, vertical wind profiles, heat and water momentum flux, non-methane hydrocarbons, trace metals, aerosol size distributions, aerosol physical properties, and surface water chlorophyll. The report contains a brief description of the experimental apparatus and procedures employed, plus graphic and tabular presentations of the data sets, for most of the data from AOML/Ocean Chemistry Division investigators.

  18. Pszenny, A.A.P., C.J. Fischer, A. Mendez, and M.P. Zetwo. Direct comparison of cellulose and quartz fiber filters for sampling submicrometer aerosols in the marine boundary layer. Atmospheric Environment, 27A(2):281-284, doi:10.1016/0960-1686(93)90359-7 1993

    Abstract:

    Paired high-volume aerosol samples of 20-60-h duration were collected using identical Sierra Model 235 cascade impactors during a July-September 1991 research cruise in the Atlantic Ocean. Whatman 41 cellulose fiber was used for the final filter in one impactor and a quartz fiber filter was used for the final filter in the other impactor during each of 17 sampling intervals. A paired t-test of measured non-seasalt sulfate (NSS) mass concentrations indicates that the retention efficiencies of the two materials for this primarily submicrometer species are indistinguishable under the conditions of our sampling. A paired t-test of ammonium concentrations indicates slightly higher concentrations on Whatman 41, suggesting, perhaps, a positive artifact due to sorption of ammonia vapor.

  19. Galloway, J.N., J.E. Penner, C.S. Atherton, J.M. Prospero, H. Rodhe, R.S. Artz, Y.J. Balkanski, H.G. Bingemer, R.A. Brost, S. Burgermeister, G.R. Carmichael, J.S. Chang, R.J. Charlson, S. Cober, W.G. Ellis, Jr., C.J. Fischer, J.M. Hales, D.R. Hastie, T. Iversen, D.J. Jacob, K. John, J.E. Johnson, P.S. Kasibhatla, J. Langner, J. Lelieveld, H. Levy, III, R. Lipschultz, J.T. Merrill, A.F. Michaels, J.M. Miller, J.L. Moody, J. Pinto, A.A.P. Pszenny, P.A. Spiro, L. Tarrason, S.M. Turner, and D.M. Whelpdale. Sulfur and nitrogen levels in the North Atlantic Ocean's atmosphere: A synthesis of field and modeling results. Global Biogeochemical Cycles, 6(2):77-100, doi:10.1029/91GB02977 1992

    Abstract:

    In April 1990, 42 scientists from eight countries attended a workshop at the Bermuda Biological Station for Research to compare field measurements with model estimates of the distribution and cycling of sulfur and nitrogen species in the North Atlantic Ocean's atmosphere. Data sets on horizontal and vertical distributions of sulfur and nitrogen species and their rates of deposition were available from ships' tracks and island stations. These data were compared with estimates produced by several climatological and event models for two case studies: (1) sulfate surface distributions and deposition; and (2) nitrate surface distributions and deposition. Highlights of the conclusions of the case studies were that the measured concentrations and model results of nitrate and non-seasalt sulfate depositions appeared to be in good agreement at some locations but in poor agreement for some months at other locations. The case studies illustrated the need for the measurement and modeling communities to interact not only to compare results, but also to cooperate in improving the designs of the models and the field experiments.

  20. Piotrowicz, S.R., C.J. Fischer, and R.S. Artz. Ozone and carbon monoxide over the North Atlantic during a boreal summer. Global Biogeochemical Cycles, 4(2):215-224, doi:10.1029/GB004i002p00215 1990

    Abstract:

    Ozone mixing ratios observed on a cruise from the east coast of North America to Bermuda, to Iceland, to the Azores, and terminating in Barbados in a boreal summer exhibit wide variability. Increases above a North Atlantic background of 10-20 ppbv appear to be associated with transport from terrestrial systems. In the central gyre of the North Atlantic and in the tropical North Atlantic, ozone mixing ratios below 10 ppbv are commonly observed when the air being sampled does not have a recent (10 days) history of terrestrial input. Carbon monoxide mixing ratios within the boundary layer vary latitudinally from an average of 124 ppbv in the westerlies to 88 ppbv in the tropical North Atlantic. Variability in the distribution of CO appears to be dominated bytransport from terrestrial source regions.

  21. Piotrowicz, S.R., D.A. Boran, and C.J. Fischer. Ozone in the boundary layer of the equatorial Pacific Ocean. Journal of Geophysical Research, 91(D12):13113-13119, doi:10.1029/JD091iD12p13113 1986

    Abstract:

    Shipboard (~7 m) ozone measurements made in the equatorial Pacific Ocean between 20°N and 17°S and 140°W-160°W confirm the existence of a distinct ozone minimum in the vicinity of the equator in the late spring, its decline in the summer, and its absence in autumn. This minimum could not be correlated with high biological activity in surface waters. Coincident aircraft measurements of ozone from near sea surface (50-100 m) to 2 km in altitude were made along 150°W at stations at 10°N, 0°, 5°S, and 12°S in May-June 1984. Aircraft data identified the existence of a distinct ozone maximum between the lifting condensation level (LCL) or cloud base and the trade wind inversion, with ozone mixing ratios amounting to 2-2.5 times the ozone levels in the well-mixed subcloud layer. A gradient of decreasing ozone with decreasing altitude extended from the LCL (or cloud base) to the near-surface superadiabatic region but did not include it.