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1969
Weiss, RF.  1969.  Dissolved argon, nitrogen and total carbonate in the Red Sea brines. Hot brines and recent heavy metal deposits in the Red Sea; a geochemical and geophysical account. ( Degens ET, Ross DA, Eds.).:254-260., New York: Springer-Verlag Abstract
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1977
Weiss, RF, Kirsten OH, Ackermann R, Ramo S.  1977.  Free vehicle instrumentation for the in-situ measurement of processes controlling the formation of deep-sea ferromanganese nodules. OCEANS '77 Conference Record. , New York, N.Y., United States (USA): Inst. Electric. and Electron. Eng., New York, N.Y.   10.1109/OCEANS.1977.1154352   Abstract

This paper describes the free vehicle instrumentation under development for the Manganese Nodule Program (MANOP) of the International Decade for Ocean Exploration (IDOE). Principal emphasis is being placed on the MANOP Bottom Lander, a device designed to carry out in situ chemical flux experiments at the seawater-sediment interface at depths up to 6 km. This device will collect time-series water samples from three separate bottom chamber experiments, each of which can be spiked with various chemical and radioisotopic tracers. The device will also make oxygen and pH measurements in each chamber and will take box core samples under each chamber before returning to the surface. All operations will be microprocessor-controlled with data storage capability and with an acoustic data-link to the surface. Deployments will be for periods of up to 1 year.

1987
Somayajulu, BLK, Rengarajan R, Lal D, Weiss RF, Craig H.  1987.  GEOSECS Atlantic 32Si profiles. Earth and Planetary Science Letters. 85:329-342.   10.1016/0012-821x(87)90131-2   AbstractWebsite

Measurements of five cosmogenic32Si vertical profiles in Atlantic waters (27°N to 60°S) are presented. The amounts of dissolved SiO2 extracted range from 2 to 54 g; the amounts of water from which SiO2 was extracted range between 540 kg and 270, 000 kg. In additon, SiO2 recovered from four surface particulate composites (64°N to 61°S) were also analyzed for32Si.32Si measurements were made by milking and counting the daughter activity, 32P. The net32P activities range from 0.7 to 6.8 cph; typical errors in measurements of the32P activities are 20–30%.The32Si concentrations vary from 0.6 dpm/106 kg of water in the North Atlantic surface waters to 235 dpm/106 kg at 400 m depth in the circumpolar waters. The vertical profiles of32Si at the five Atlantic stations approximately follow the Si profiles but the depth gradients are different. This would be expected also considering the in-situ release mechanisms due to dissolution and advection/diffusion from the bottom waters. Except for the circumpolar station 89, where the Si and32Si profiles show the effect of marked vertical mixing (nearly depth independent profiles), the profiles show the following features: (1) specific activities of32Si (32Si/SiO2 ratios) are lowest at intermediate depths, and (2) on an average the surface specific activities are higher, by 2–4 times, than the bottom water values. These data are consistent with generation of the highest specific activity32Si waters at the surface, where Si concentrations are lowest and precipitation adds cosmogenic32Si scavenged from the troposphere. Rapid removal of biogenic silica to the water-sediment interface, without much dissolution during transit, leads to the second regime of high32Si specific activities.The32Si inventories in the water column in the latitude belt 27°N-27°S are in the range (1–1.4) × 10−2 dpm32Si/cm2, which is consistent with the expected fallout of cosmogenic32Si. However, the32Si column inventories south of 40°S are higher by a factor of ∼ 5–7, whereas the corresponding Si inventories increase by only a factor of 3. This excess32Si in the Southern Ocean cannot be explained by direct fallout from the stratosphere or by melting of Antarctic snow and ice. Instead, this excess is maintained primarily by the southward deep-water transport of32Si dissolved from sinking particulates.

1993
Reverdin, G, Weiss RF, Jenkins WJ.  1993.  Ventilation of the Atlantic Ocean equatorial thermocline. Journal of Geophysical Research-Oceans. 98:16289-16310.   10.1029/93jc00976   AbstractWebsite

The ventilation of the lower equatorial Atlantic thermocline (100 m to 400 m) is investigated from the distributions of salinity, oxygen, the chlorofluoromethanes F-11 and F-12, tritium, and the excess helium 3; 1983 data suggest a correlation on isopycnal surfaces between oxygen, chlorofluoromethanes and to a lesser extent, with the apparent ages derived from F-11/F-12 and helium 3/tritium. The apparent ages increase with depth from 10 years on sigma(THETA)=26.5 to over 15 years near 400 m. The tracers are largely undersaturated with respect to the surface concentrations corresponding to the apparent ages. We investigate the ventilation processes responsible for these distributions with simple circulation models, where water from the subtropical gyres reaches isopycnally the equatorial thermocline. The few model parameters are determined by fitting the simulations to the chlorofluoromethane distributions in 1983. The sensitivity of these parameters to expected errors on the past surface concentrations and to vertical mixing is comparable and can result in an error of more than 20% in the model parameters. In 1983, model [H-3] and [He-3]* are too large, in particular when no diapycnal mixing is modeled, but the differences could have arisen from errors on past surface concentrations. During the 1980s, die model overestimates the increase in chlorofluoromethanes, in particular F-12. The fitted model inflow from the southern subtropical gyre between 110 m and 400 m is 14 x 10(6) m3 s-1, in the range of expected transports by the western boundary current near Brazil. The model oxygen utilization rate is on the order of 12 mmol kg-1 yr-1 at 100 m and 5 mmol kg-1 yr-1 at 400 m (below sigma(theta)=27.1).

1995
Penkett, SA, Butler JH, Kurylo MJ, Reeves CE, Rodriguez JM, Singh H, Toohey D, Weiss R.  1995.  Methyl bromide. Scientific assessment of ozone depletion: 1994 (World Meterological Organization, Global Ozone Research and Monitoring Report). ( World Meteorological O, Ed.).:26., Geneva, Switzerland; Nairobi, Kenya; Washington, DC, USA: World Meteorological Organization Abstract
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1998
Broecker, WS, Peacock SL, Walker S, Weiss R, Fahrbach E, Schroeder M, Mikolajewicz U, Heinze C, Key R, Peng TH, Rubin S.  1998.  How much deep water is formed in the Southern Ocean? Journal of Geophysical Research-Oceans. 103:15833-15843.   10.1029/98jc00248   AbstractWebsite

Three tracers are used to place constraints on the production rate of ventilated deep water in the Southern Ocean. The distribution of the water mass tracer PO4* ("phosphate star") in the deep sea suggests that the amount of ventilated deep water produced in the Southern Ocean is equal to or greater than the outflow of North Atlantic Deep Water from the Atlantic. Radiocarbon distributions yield an export flux of water from the North Atlantic which has averaged about 15 Sv over the last several hundred years. CFC inventories are used as a direct indicator of the current production rate of ventilated deep water in the Southern Ocean. Although coverage is as yet sparse, it appears that the CFC inventory is not inconsistent with the deep water production rate required by the distributions of PO4* and radiocarbon. It has been widely accepted that the major part of the deep water production in the Southern Ocean takes place in the Weddell Sea. However, our estimate of the Southern Ocean ventilated deep water flux is in conflict with previous estimates of the flux of ventilated deep water from the Weddell Sea, which lie in the range 1-5 Sv. Possible reasons for this difference are discussed.

1999
Prinn, RG, Zander R, Cunnold DM, Elkins JW, Engel A, Fraser PJ, Gunson MR, Ko MKW, Mahieu E, Midgley PM, Russel III JM, Volk CM, Weiss RF.  1999.  Long-lived ozone-related compounds. Scientific assessment of ozone depletion, 1998 (World Meteorological Organization, Global Ozone Research and Monitoring Project Report 44). :54., Washington, DC: National Oceanic and Atmospheric Administration Abstract
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Kurylo, MJ, Rodriguez JM, Andreae MO, Atlas EL, Blake DR, Butler JH, Lal S, Lary DJ, Midgley PM, Montzka SA, Novelli PC, Reeves CE, Simmonds PG, Steele LP, Sturges WT, Weiss RF, Yokouchi Y.  1999.  Short-lived ozone-related compounds. Scientific assessment of ozone depletion, 1998 (World Meteorological Organization, Global Ozone Research and Monitoring Project Report 44). :56., Washington, DC: National Oceanic and Atmospheric Administration Abstract
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2000
Rhew, RC, Miller BR, Weiss RF.  2000.  Natural methyl bromide and methyl chloride emissions from coastal salt marshes. Nature. 403:292-295.   10.1038/35002043   AbstractWebsite

Atmospheric methyl bromide (CH3Br) and methyl chloride (CH3Cl), compounds that are involved in stratospheric ozone depletion, originate from both natural and anthropogenic sources. Current estimates of CH3Br and CH3Cl emissions from oceanic sources, terrestrial plants and fungi, biomass burning and anthropogenic inputs do not balance their losses owing to oxidation by hydroxyl radicals, oceanic degradation, and consumption in soils, suggesting that additional natural terrestrial sources may be important(1). Here we show that CH3Br and CH3Cl are released to the atmosphere from all vegetation zones of two coastal salt marshes. We see very large fluxes of CH3Br and CH3Cl per unit area: up to 42 and 570 mu mol m(-2) d(-1), respectively. The fluxes show large diurnal, seasonal and spatial variabilities, but there is a strong correlation between the fluxes of CH3Br and those of CH3Cl, with an average molar flux ratio of roughly 1:20. If our measurements are typical of salt marshes globally, they suggest that such ecosystems, even though they constitute less than 0.1% of the global surface area(2), may produce roughly 10% of the total fluxes of atmospheric CH3Br and CH3Cl.

2001
O'Doherty, S, Simmonds PG, Cunnold DM, Wang HJ, Sturrock GA, Fraser PJ, Ryall D, Derwent RG, Weiss RF, Salameh P, Miller BR, Prinn RG.  2001.  In situ chloroform measurements at Advanced Global Atmospheric Gases Experiment atmospheric research stations from 1994 to 1998. Journal of Geophysical Research-Atmospheres. 106:20429-20444.   10.1029/2000jd900792   AbstractWebsite

Measurements of atmospheric chloroform (CHCl3) by in situ gas chromatography using electron capture detection are reported from the Advanced Global Atmospheric Gases Experiment (AGAGE) network of atmospheric research stations. They are some of the most comprehensive in situ, high-frequency measurements to be reported for CHCl3 and provide valuable information not only on clean "baseline" mixing ratios but also on local and regional sources. Emissions from these sources cause substantial periodic increases in CHCl3 concentrations above their baseline levels, which can be used to identify source strengths. This is particularly the case for measurements made at Mace Head, Ireland. Furthermore, these local sources of CHCl3 emissions are significant in relation to current estimates of global emissions and illustrate that the understanding of competing sources and sinks of CHCl3 is still fragmentary. These observations also show that CHCl3 has a very pronounced seasonal cycle with a summer minimum and winter maximum presumably resulting from enhanced destruction by OH in the summer. The amplitude of the cycle is dependent on sampling location. Over the 57 months of in situ measurements a global average baseline concentration of 8.9 +/-0.1 ppt was determined with no appreciable trend in the baseline detected.

Rhew, RC, Miller BR, Vollmer MK, Weiss RF.  2001.  Shrubland fluxes of methyl bromide and methyl chloride. Journal of Geophysical Research-Atmospheres. 106:20875-20882.   10.1029/2001jd000413   AbstractWebsite

Flux measurements in coastal sage scrub, chamise chaparral, and creosote bush scrub environments show that methyl bromide (CH(3)Br) and methyl chloride (CH(3)Cl), compounds that are involved in stratospheric ozone depletion, are both produced and consumed by southern California shrubland ecosystems. CH(3)Br and CH(3)Cl are produced in association with a variety of plants and are consumed by the soils, although there is a large variability in the fluxes, depending on predominant vegetation and environmental conditions. At sites with a net uptake of both compounds the fluxes of CH(3)Cl and CH(3)Br show a strong correlation, with a molar ratio of roughly 40:1, pointing to a similar mechanism of consumption. In contrast, the net production rates of these compounds show no apparent correlation with each other. The average observed net CH(3)Br uptake rates are an order of magnitude smaller than the previously reported average soil consumption rates assigned to shrublands. Extrapolations from our field measurements suggest that shrublands globally have a maximum net consumption of <1 Gg yr(-1) for CH(3)Br and < 20 Gg yr(-1) for CH(3)Cl and may, in fact, be net sources for these compounds. Consequently, the measured net fluxes from shrubland ecosystems can account for part of the present imbalance in the CH(3)Br budget by adding a new source term and potentially reducing the soil sink term. These results also suggest that while shrubland soil consumption of CH(3)Cl may be small, soils in general may be a globally significant sink for CH(3)Cl.

2002
Klatt, O, Roether W, Hoppema M, Bulsiewicz K, Fleischmann U, Rodehacke C, Fahrbach E, Weiss RF, Bullister JL.  2002.  Repeated CFC sections at the Greenwich Meridian in the Weddell Sea. Journal of Geophysical Research-Oceans. 107   10.1029/2000jc000731   AbstractWebsite

[1] Repeated observations of the tracer chlorofluorocarbon-11 (CFC-11) for a section along the Greenwich Meridian from Antarctica (70degreesS) to about 50 S are presented for the period 1984-1998. The CFC sections display a highly persistent pattern. A middepth CFC minimum in the central Weddell Sea is bounded laterally by elevated levels of dissolved CFCs at the southern margin of the Weddell Basin and by a column of elevated CFC concentrations around 55degreesS near to the northern margin. Part of the latter column covers waters of the Antarctic Circumpolar Current, which indicates that a moderate portion of these waters was ventilated in the Weddell Sea. Deep CFC maxima adjoining the southern and northern margins of the Weddell Basin indicate advective cores of recently ventilated waters. The southern core supports previous notions of deep water import into the Weddell Sea from the east. For all deep and bottom waters, the portions ventilated on the CFC timescale (similar to50 years) are small. Effective initial CFC saturations for these portions are estimated to be between 60 and 70%, using in part new data from off the Filchner-Ronne Ice Shelf. For various CFC features along the section (mostly advective cores), ventilated fractions and mean ages of these fractions were obtained (with error limits). The procedure was to fit an age distribution of a prescribed form to CFC-11 time series for these features, constructed from the various realizations of the CFC section. The ages are between 3 and 19 years, and the ventilated fractions range between 6 and 23%, indicating a rather limited ventilation of the interior Weddell Sea subsurface layer waters on the CFC timescale. It is shown that the concurrent CFC-12 data provide little additional information. The work demonstrates a high information content of repeated tracer observations and encourages similar approaches also in other ocean regions.

Vollmer, MK, Weiss RF, Williams RT, Falkner KK, Qiu X, Ralph EA, Romanovsky VV.  2002.  Physical and chemical properties of the waters of saline lakes and their importance for deep-water renewal: Lake Issyk-Kul, Kyrgyzstan. Geochimica Et Cosmochimica Acta. 66:4235-4246.   10.1016/s0016-7037(02)01052-9   AbstractWebsite

The relationships between electrical conductivity, temperature, salinity, and density are studied for brackish Lake Issyk-Kul. These studies are based on a newly determined major ion composition, which for the open lake shows a mean absolute salinity of 6.06 g kg(-1). The conductivity-temperature relationship of the lake water was determined experimentally showing that the lake water is about 1.25 times less conductive than seawater diluted to the same absolute salinity as that of the lake water. Based on these results, an algorithm is presented to calculate salinity from in-situ conductivity measurements. Applied to the field data, this shows small but important vertical salinity variations in the lake with a salinity maximum at 200 m and a freshening of the surface water with increasing proximity to the shores. The algorithm we adopt to calculate density agrees well with earlier measurements and shows that at 20degreesC and I atm Lake Issyk-Kul water is about 530 g m(-3) denser than seawater at the same salinity. The temperature of maximum density at I atm is about 0.15degreesC lower than that for seawater diluted to the same salinity. Despite its small variations, salinity plays an important role, together with temperature changes, in the static stability and in the production of deep-water in this lake. Changes in salinity may have had important consequences on the mixing regime and the fate of inflowing river water over geological time. Uncharged silicic acid is negligible for the stability of the water column except near an similar to15 m thick nepheloid layer observed at the bottom of the deep basin. Copyright (C) 2002 Elsevier Science Ltd.

Bill, M, Rhew RC, Weiss RF, Goldstein AH.  2002.  Carbon isotope ratios of methyl bromide and methyl chloride emitted from a coastal salt marsh. Geophysical Research Letters. 29   10.1029/2001gl012946   AbstractWebsite

[1] Methyl bromide (CH3Br) and methyl chloride (CH3Cl) play important roles in stratospheric ozone depletion, but their atmospheric budgets have large uncertainties. The analysis of stable isotope composition of methyl halides may provide useful independent information for further constraining their budgets. Here we report the first measurements of CH3Br and CH3Cl stable carbon isotope ratios emitted from a biogenic source under in situ conditions. CH3Br and CH3Cl emissions from the salt marsh plant Batis maritima showed a strong diurnal variation in delta(13)C, from -65parts per thousand during the daytime to --12parts per thousand at night. The minimum delta(13)C values were observed at midday, coinciding with the time of greatest emissions and ambient temperature. At night, when the emissions were much smaller, the stable carbon isotopic ratios of CH3Br and CH3Cl became enriched in C-13. The daily mean delta(13)C of CH3Br and CH3Cl emissions, weighted by emission rate, were -43parts per thousand and -62parts per thousand respectively.

Rhein, M, Fischer J, Smethie WM, Smythe-Wright D, Weiss RF, Mertens C, Min DH, Fleischmann U, Putzka A.  2002.  Labrador Sea Water: pathways, CFC inventory, and formation rates. Journal of Physical Oceanography. 32:648-665.   10.1175/1520-0485(2002)032<0648:lswpci>2.0.co;2   AbstractWebsite

In 1997, a unique hydrographic and chlorofluorocarbon (CFC: component CFC-11) dataset was obtained in the subpolar North Atlantic. To estimate the synopticity of the 1997 data, the recent temporal evolution of the CFC and Labrador Sea Water (LSW) thickness fields are examined. In the western Atlantic north of 50degreesN, the LSW thickness decreased considerably from 1994-97, while the mean CFC concentrations did not change much. South of 50degreesN and in the eastern Atlantic, the CFC concentration increased with little or no change in the LSW thickness. On shorter timescales, local anomalies due to the presence of eddies are observed, but for space scales larger than the eddies the dataset can be treated as being synoptic over the 1997 observation period. The spreading of LSW in the subpolar North Atlantic is described in detail using gridded CFC and LSW thickness fields combined with Profiling Autonomous Lagrangian Circulation Explorer (PALACE) float trajectories. The gridded fields are also used to calculate the CFC-11 inventory in the LSW from 40degrees to 65degreesN, and from 10degrees to 60degreesW. In total, 2300 +/- 250 tons of CFC-11 (equivalent to 16.6 million moles) were brought into the LSW by deep convection. In 1997, 28% of the inventory was still found in the Labrador Sea west of 45degreesW and 31% of the inventory was located in the eastern Atlantic. The CFC inventory in the LSW was used to estimate the lower limits of LSW formation rates. At a constant formation rate, a value of 4.4-5.6 Sv (Sv = 10(6) m(3) s(-1)) is obtained. If the denser modes of LSW are ventilated only in periods with intense convection, the minimum formation rate of LSW in 1988-94 is 8.1-10.8 Sv, and 1.8-2.4 Sv in 1995-97.

Rhew, RC, Miller BR, Bill M, Goldstein AH, Weiss RF.  2002.  Environmental and biological controls on methyl halide emissions from southern California coastal salt marshes. Biogeochemistry. 60:141-161.   10.1023/a:1019812006560   AbstractWebsite

Methyl bromide (CH3Br) and methyl chloride (CH3Cl) emission rates from southern California coastal salt marshes show large spatial and temporal variabilities that are strongly linked to biological and environmental factors. Here we discuss biogeochemical lines of evidence pointing to vegetation as the primary source of CH3Br and CH3Cl emissions from salt marshes. Sediments and macroalgae do not appear to be major producers of these compounds, based on observations that the highest fluxes are not inhibited by soil inundation; their emissions are not correlated with those of certain gases produced in soils; and emissions from mudflat- and macroalgae-dominated sites are relatively small. In contrast, the seasonal and spatial variabilities of methyl halide fluxes in these salt marshes are consistent with the production of these compounds by vascular plants, although the possibility of production by microflora or fungi associated with the salt marsh vegetation is not ruled out. Flux chamber measurements of emission rates are largely correlated to the overall plant biomass enclosed in the chamber, but appear also to be highly dependent on the predominant plant species. Emission rates follow a diurnal trend similar to the trends of ambient air temperature and photosynthetically active radiation, but not surface soil temperature. Diurnal variabilities in the carbon isotope compositions of CH3Cl and CH3Br and their relative ratios of emissions are consistent with simultaneously competing mechanisms of uptake and production.

2003
Montzka, SA, Fraser PJ, Butler JH, Connell PS, Cunnold DM, Daniel JS, Derwent RG, Lal S, McCulloch A, Oram D, Reeves CE, Sanhueza E, Steele LP, Velders GJM, Weiss RF, Zander R.  2003.  Controlled substances and other source gases. Scientific assessment of ozone depletion, 2002 (World Meteorological Organization, Global Ozone Research and Monitoring Project, Report 47). :83., Washington, DC: National Oceanic and Atmospheric Administration Abstract
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2004
Fraser, PJ, Porter LW, Baly SB, Krummel PB, Dunse BL, Steele LP, Derek N, Langenfelds RL, Levin I, Oram DE, Elkins JW, Vollmer MK, Weiss RF.  2004.  Sulfur hexafluoride at Cape Grim: Long term trends and regional emissions, Baseline 2001-2002. :18-23., Melbourne Abstract
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Simmonds, PG, Derwent RG, Manning AJ, Fraser PJ, Krummel PB, O'Doherty S, Prinn RG, Cunnold DM, Miller BR, Wang HJ, Ryall DB, Porter LW, Weiss RF, Salameh PK.  2004.  AGAGE observations of methyl bromide and methyl chloride at Mace Head, Ireland, and Cape Grim, Tasmania, 1998-2001. Journal of Atmospheric Chemistry. 47:243-269.   10.1023/B:JOCH.0000021136.52340.9c   AbstractWebsite

In situ AGAGE GC-MS measurements of methyl bromide (CH3Br) and methyl chloride (CH3Cl) at Mace Head, Ireland and Cape Grim, Tasmania (1998-2001) reveal a complex pattern of sources. At Mace Head both gases have well-defined seasonal cycles with similar average annual decreases of 3.0% yr(-1) (CH3Br) and 2.6% yr(-1) (CH3Cl), and mean northern hemisphere baseline mole fractions of 10.37 +/- 0.05 ppt and 535.7 +/- 2.2 ppt, respectively. We have used a Lagrangian dispersion model and local meteorological data to segregate the Mace Head observations into different source regions, and interpret the results in terms of the known sources and sinks of these two key halocarbons. At Cape Grim CH3Br and CH3Cl also show annual decreases in their baseline mixing ratios of 2.5% yr(-1) and 1.5% yr(-1), respectively. Mean baseline mole fractions were 7.94 +/- 0.03 ppt (CH3Br) and 541.3 +/- 1.1 ppt (CH3Cl). Although CH3Cl has a strong seasonal cycle there is no well-defined seasonal cycle in the Cape Grim CH3Br record. The fact that both gases are steadily decreasing in the atmosphere at both locations implies that a change has occurred which is affecting a common, major source of both gases (possibly biomass burning) and/or their major sink process (destruction by hydroxyl radical).

O'Doherty, S, Cunnold DM, Manning A, Miller BR, Wang RHJ, Krummel PB, Fraser PJ, Simmonds PG, McCulloch A, Weiss RF, Salameh P, Porter LW, Prinn RG, Huang J, Sturrock G, Ryall D, Derwent RG, Montzka SA.  2004.  Rapid growth of hydrofluorocarbon 134a and hydrochlorofluorocarbons 141b, 142b, and 22 from Advanced Global Atmospheric Gases Experiment (AGAGE) observations at Cape Grim, Tasmania, and Mace Head, Ireland. Journal of Geophysical Research-Atmospheres. 109   10.1029/2003jd004277   AbstractWebsite

[1] An update of in situ Advanced Global Atmospheric Gases Experiment (AGAGE) hydrofluorocarbon (HFC)/hydrochlorofluorocarbon ( HCFC) measurements made at Mace Head, Ireland, and Cape Grim, Tasmania, from 1998 to 2002 are reported. HCFC-142b, HCFC-141b, HCFC-22 and HFC-134a show continued rapid growth in the atmosphere at mean rates of 1.1, 1.6, 6.0, and 3.4 ppt/year, respectively. Emissions inferred from measurements are compared to recent estimates from consumption data. Minor updates to the industry estimates of emissions are reported together with a discussion of how to best determine OH concentrations from these trace gas measurements. In addition, AGAGE measurements and derived emissions are compared to those deduced from NOAA-Climate Monitoring and Diagnostics Laboratory flask measurements ( which are mostly made at different locations). European emission estimates obtained from Mace Head pollution events using the Nuclear Accident Model ( NAME) dispersion model and the best fit algorithm ( known as simulated annealing) are presented as 3-year rolling average emissions over Europe for the period 1999-2001. Finally, the measurements of HCFC-141b, HCFC-142b, and HCFC-22 discussed in this paper have been combined with the Atmospheric Lifetime Experiment (ALE)/Global Atmospheric Gases Experiment (GAGE)/AGAGE measurements of CFC-11, CFC-12, CFC-113, CCl4, and CH3CCl3 to produce the evolution of tropospheric chlorine loading.

2005
Prinn, RG, Huang J, Weiss RF, Cunnold DM, Fraser PJ, Simmonds PG, McCulloch A, Harth C, Reimann S, Salameh P, O'Doherty S, Wang RHJ, Porter LW, Miller BR, Krummel PB.  2005.  Evidence for variability of atmospheric hydroxyl radicals over the past quarter century. Geophysical Research Letters. 32   10.1029/2004gl022228   AbstractWebsite

The hydroxyl free radical (OH) is the major oxidizing chemical in the atmosphere, destroying about 3.7 petagrams (Pg) of trace gases each year, including many gases involved in ozone depletion, the greenhouse effect and urban air pollution. Measurements of 1,1,1-trichloroethane (methyl chloroform, CH3CCl3), which reacts with OH, provide the most accurate method currently utilized for determining the global behavior of OH. We report that CH3CCl3 levels rose steadily from 1978 to reach a maximum in 1992 and have since decreased rapidly to levels in 2004 about 30% of the levels when measurements began in 1978. Analysis of these observations shows that global average OH levels had a small maximum around 1989 and a larger minimum around 1998, with OH concentrations in 2003 being comparable to those in 1979. This post-1998 recovery of OH reported here contrasts with the situation 4 years ago when reported OH was decreasing. The 1997-1999 OH minimum coincides with, and is likely caused by, major global wildfires and an intense El Nino event at this time.

Reimann, S, Manning AJ, Simmonds PG, Cunnold DM, Wang RHJ, Li JL, McCulloch A, Prinn RG, Huang J, Weiss RF, Fraser PJ, O'Doherty S, Greally BR, Stemmler K, Hill M, Folini D.  2005.  Low European methyl chloroform emissions inferred from long-term atmospheric measurements. Nature. 433:506-508.   10.1038/nature03220   AbstractWebsite

Methyl chloroform (CH3CCl3, 1,1,1,-trichloroethane) was used widely as a solvent before it was recognized to be an ozone-depleting substance and its phase-out was introduced under the Montreal Protocol(1). Subsequently, its atmospheric concentration has declined steadily(2-4) and recent European methyl chloroform consumption and emissions were estimated to be less than 0.1 gigagrams per year(1,5). However, data from a short-term tropospheric measurement campaign ( EXPORT) indicated that European methyl chloroform emissions could have been over 20 gigagrams in 2000 (ref. 6), almost doubling previously estimated global emissions(1,4). Such enhanced emissions would significantly affect results from the CH3CCl3 method of deriving global abundances of hydroxyl radicals ( OH) (refs 7 - 12) - the dominant reactive atmospheric chemical for removing trace gases related to air pollution, ozone depletion and the greenhouse effect. Here we use long-term, high-frequency data from MaceHead, Ireland and Jungfraujoch, Switzerland, to infer European methyl chloroform emissions. We find that European emission estimates declined from about 60 gigagrams per year in the mid-1990s to 0.3 - 1.4 and 1.9 - 3.4 gigagrams per year in 2000 - 03, based on Mace Head and Jungfraujoch data, respectively. Our European methyl chloroform emission estimates are therefore higher than calculated from consumption data(1,5), but are considerably lower than those derived from the EXPORT campaign in 2000 ( ref. 6).

2007
Forster, P, Ramaswamy V, Artaxo P, Berntsen J, Betts R, Fahey DW, Haywood J, Lean J, Lowe DC, Myhre G, Nganga J, Prinn R, Raga G, Schulz M, van Dorland R, Bodeker G, Boucher O, Collins WD, Conway TJ, Dlugokencky E, Elkins JW, Etheridge D, Foukal P, Fraser P, Geller M, Joos F, Keeling CD, Keeling R, Kinne S, Lassey K, Lohmann U, Manning AC, Montzka SA, Oram D, O'Shaughnessy K, Piper SC, Plattner GK, Ponater M, Ramankutty N, Reid GC, Rind D, Rosenlof KH, Sausen R, Schwarzkopf D, Solanki SK, Stenchikov G, Stuber N, Takemura T, Textor C, Wang R, Weiss R, Whorf T.  2007.  Changes in atmospheric constituents and in radiative forcing. Climate Change 2007 : The Physical Science Basis : Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. ( Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt K, Tignor M, Miller H, Eds.).:129-234., Cambridge; New York: Cambridge University Press Abstract

For policymakers -- Technical summary -- Historical overview of climate change science -- Changes in atmospheric constituents and radiative forcing -- Observations: atmospheric surface and climate change -- Observations: changes in snow, ice, and frozen ground -- Observations: ocean climate change and sea level -- Paleoclimate -- Coupling between changes in the climate system and biogeochemistry -- Climate models and their evaluation -- Understanding and attributing climate change -- Global climate projections -- Regional climate projections -- Annex I: Glossary -- Annex II: Contributors to the IPCC WGI Fourth Assessment Report -- Annex III: Reviewers of the IPCC WGI Fourth Assessment Report -- Annex IV: Acronyms.

Clerbaux, C, Cunnold DM, Anderson J, Engel AEJ, Fraser PJ, Mahieu E, Manning A, Miller J, Montzka SA, Nassar R, Prinn R, Reimann S, Rinsland CP, Simmonds P, Verdonik D, Weiss R, Wuebbles D, Yokouchi K.  2007.  Long-lived compounds. Scientific assessment of ozone depletion, 2006 (World Meteorological Organization, Global Ozone Research and Monitoring Project, Report 50). :83., Geneva, Switzerland: World Meteorological Organization Abstract
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Greally, BR, Manning AJ, Reimann S, McCulloch A, Huang J, Dunse BL, Simmonds PG, Prinn RG, Fraser PJ, Cunnold DM, O'Doherty S, Porter LW, Stemmler K, Vollmer MK, Lunder CR, Schmidbauer N, Hermansen O, Arduini J, Salameh PK, Krummel PB, Wang RHJ, Folini D, Weiss RF, Maione M, Nickless G, Stordal F, Derwent RG.  2007.  Observations of 1,1-difluoroethane (HFC-152a) at AGAGE and SOGE monitoring stations in 1994-2004 and derived global and regional emission estimates. Journal of Geophysical Research-Atmospheres. 112   10.1029/2006jd007527   AbstractWebsite

[1] Ground-based in situ measurements of 1,1-difluoroethane (HFC-152a, CH3CHF2) which is regulated under the Kyoto Protocol are reported under the auspices of the AGAGE (Advanced Global Atmospheric Gases Experiment) and SOGE (System of Observation of halogenated Greenhouse gases in Europe) programs. Observations of HFC-152a at five locations (four European and one Australian) over a 10 year period were recorded. The annual average growth rate of HFC-152a in the midlatitude Northern Hemisphere has risen from 0.11 ppt/yr to 0.6 ppt/yr from 1994 to 2004. The Southern Hemisphere annual average growth rate has risen from 0.09 ppt/yr to 0.4 ppt/yr from 1998 to 2004. The 2004 average mixing ratio for HFC-152a was 5.0 ppt and 1.8 ppt in the Northern and Southern hemispheres, respectively. The annual cycle observed for this species in both hemispheres is approximately consistent with measured annual cycles at the same locations in other gases which are destroyed by OH. Yearly global emissions of HFC-152a from 1994 to 2004 are derived using the global mean HFC-152a observations and a 12-box 2-D model. The global emission of HFC-152a has risen from 7 Kt/yr to 28 Kt/yr from 1995 to 2004. On the basis of observations of above-baseline elevations in the HFC-152a record and a consumption model, regional emission estimates for Europe and Australia are calculated, indicating accelerating emissions from Europe since 2000. The overall European emission in 2004 ranges from 1.5 to 4.0 Kt/year, 5-15% of global emissions for 1,1-difluoroethane, while the Australian contribution is negligible at 5-10 tonnes/year, < 0.05% of global emissions.