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Li, JL, Cunnold DM, Wang HJ, Weiss RF, Miller BR, Harth C, Salameh P, Harris JM.  2005.  Halocarbon emissions estimated from advanced global atmospheric gases experiment measured pollution events at Trinidad Head, California. Journal of Geophysical Research-Atmospheres. 110   10.1029/2004jd005739   AbstractWebsite

The emissions of halogenated gases from the West Coast region of the United States are estimated from measurements from 1995 to 2003 at the Advanced Global Atmospheric Gases Experiment site at Trinidad Head, California. The emissions estimation procedure uses pollution events combined with population densities integrated along back trajectories, and the estimates are constrained by independent estimates of CH4 and N2O emissions from the U. S. West Coast region. The best fit, average emissions of CH4 and N2O and the average chloroform emissions in California, Oregon, and Washington combined from 1996 to 2002 are 44, 3.7, and 0.07 kg person(-1) yr(-1), respectively. The emissions per person of CFC-11 (CCl3F), CFC-2 (CCl2F2), CFC-113 (CCl2FCClF2), and methyl chloroform (CH3CCl3) from California in 1996-1998 are calculated to be factors of approximately 2.2, 1.3, 0.7, and 1.6, respectively, less (more for CFC-113) than those reported for the northeastern United States by Barnes et al. (2003). The emission per person of all these gases in the U. S. West Coast region decreased from 1998 to 1999 by a factor of 2 or more, but from 1999 to 2002 the estimated emissions of all four gases have remained fairly constant and are 0.016, 0.048, 0.002, and 0.006 kg person(-1) yr(-1), respectively. The methyl chloroform estimates suggest a delay of up to 1 year in the decline of the emissions from 1996 to 1998, but otherwise, and in 1999-2000, in contrast to the Millet and Goldstein (2004) results, they are in agreement with the average methyl chloroform emissions per person for the United States based on the UNEP country by country consumption figures (A. McCulloch, private communication, 2004). Averaging the Trinidad Head and the Barnes et al. (2003) per person estimates and multiplying by the U. S. population suggests average methyl chloroform emissions in the United States of 18 Gg yr(-1) in 1996 to 1998. In 2001-2002, if the ratio of the emissions per person in these two regions was the same as in 1996-1998, we estimate U. S. emissions of 2.2 Gg yr(-1), which is one half of the Millet and Goldstein (2004) estimate.

Weiss, RF.  1970.  Helium isotope effect in solution in water and seawater. Science. 168:247-248.   10.1126/science.168.3928.247   AbstractWebsite

The isotope effect in the solution of helium in water from 0° to 40°C has been determined by microgasometric measurements of the solubilities of pure helium-3 and helium4. At 0°C helium-3 is less soluble than helium-4 in both distilled water and sea-water by 1.2 percent. The observed fractionation factor is 0.988±0.002 at 0°C and appears to decrease with increasing temperature at the rate of 0.0001 per degree Centigrade, although the existence of this trend is of limited statistical certainty. The measured isotope effect is in agreement with the ratio of helium-3 to helium-4 in surface ocean water reported by Clarke, Beg, and Craig.

Lupton, JE, Klinkhammer GP, Normark WR, Haymon R, Macdonald KC, Weiss RF, Craig H.  1980.  Helium-3 and manganese at the 21°N East Pacific Rise hydrothermal site. Earth and Planetary Science Letters. 50:115-127.   10.1016/0012-821x(80)90123-5   AbstractWebsite

Water samples collected at the 21°N hydrothermal site on the East Pacific Rise crest, including Deep-Tow and hydrocast samples collected in 1977 and three hot vent water samples collected recently with the submersible “Alvin”, contain significant additions of3He,4He, and Mn. Although the vent water collections were at least 50-fold diluted with ambient seawater, they are up to 53 times enriched in3He and 7.4 times enriched in4He relative to saturated seawater, with concentrations of total dissolvable manganese (TDM) up to 310 μg/kg.3He and4He covary in the vent samples, with3He/4He about 8 times the atmospheric ratio, reflecting a mantle helium source. In contrast to the helium isotopes the Mn/3He ratio in the vent samples is variable, ranging from 4.3 × 104 up to 1.0 × 105 g/cm3. Profiles of3He/4He and TDM in the water column at 21°N show a sharp maximum ofδ(3He) = 47%and TDM= 0.69 μg/kg, much higher than the average values of 34% and 0.2 μg/kg for the deep water in this region. This spike in3He and Mn occurs at 2400 m depth, 200 m above the level of the 21°N vents, and 100 m higher than any local bathymetry, evidence for upward transport of the hydrothermal discharge via rising plumes of hot vent water. Two of the 21°N Deep-Tow samples associated with small (⩽0.010°C) temperature anomalies hadδ(3He) = 38%and TDM= 0.28 and 0.58 μg/kg, also slightly elevated relative to background. The Deep-Tow and hydrocast samples have lower Mn/3He ratios than average vent samples due to Mn removal by scavenging. Comparison of vent samples and water column measurements at 21°N indicate that the pure vent water could be detected using3He and Mn even when diluted ∼105 times with seawater, confirming that these two tracers are extremely sensitive indicators of submarine hydrothermal activity.

Miller, BR, Rigby M, Kuijpers LJM, Krummel PB, Steele LP, Leist M, Fraser PJ, McCulloch A, Harth C, Salameh P, Muhle J, Weiss RF, Prinn RG, Wang RHJ, O'Doherty S, Greally BR, Simmonds PG.  2010.  HFC-23 (CHF3) emission trend response to HCFC-22 (CHClF2) production and recent HFC-23 emission abatement measures. Atmospheric Chemistry and Physics. 10:7875-7890.   10.5194/acp-10-7875-2010   AbstractWebsite

HFC-23 (also known as CHF(3), fluoroform or trifluoromethane) is a potent greenhouse gas (GHG), with a global warming potential (GWP) of 14 800 for a 100-year time horizon. It is an unavoidable by-product of HCFC-22 (CHClF(2), chlorodifluoromethane) production. HCFC-22, an ozone depleting substance (ODS), is used extensively in commercial refrigeration and air conditioning, in the extruded polystyrene (XPS) foam industries (dispersive applications) and also as a feedstock in fluoropolymer manufacture (a non-dispersive use). Aside from small markets in specialty uses, HFC-23 has historically been considered a waste gas that was, and often still is, simply vented to the atmosphere. Efforts have been made in the past two decades to reduce HFC-23 emissions, including destruction (incineration) in facilities in developing countries under the United Nations Framework Convention on Climate Change's (UNFCCC) Clean Development Mechanism (CDM), and by process optimization and/or voluntary incineration by most producers in developed countries. We present observations of lower-tropospheric mole fractions of HFC-23 measured by 'Medusa' GC/MSD instruments from ambient air sampled in situ at the Advanced Global Atmospheric Gases Experiment (AGAGE) network of five remote sites (2007-2009) and in Cape Grim air archive (CGAA) samples (1978-2009) from Tasmania, Australia. These observations are used with the AGAGE 2-D atmospheric 12-box model and an inverse method to produce model mole fractions and a 'top-down' HFC-23 emission history. The model 2009 annual mean global lower-tropospheric background abundance is 22.6 (+/- 0.2) pmol mol(-1). The derived HFC-23 emissions show a 'plateau' during 1997-2003, followed by a rapid similar to 50% increase to a peak of 15.0 (+1.3/-1.2) Gg/yr in 2006. Following this peak, emissions of HFC-23 declined rapidly to 8.6 (+0.9/-1.0) Gg/yr in 2009, the lowest annual emission of the past 15 years. We derive a 1990-2008 'bottom-up' HFC-23 emission history using data from the United Nations Environment Programme and the UNFCCC. Comparison with the top-down HFC-23 emission history shows agreement within the stated uncertainties. In the 1990s, HFC-23 emissions from developed countries dominated all other sources, then began to decline and eventually became fairly constant during 2003-2008. By this point, with developed countries' emissions essentially at a plateau, the major factor controlling the annual dynamics of global HFC-23 emissions became the historical rise of developing countries' HCFC-22 dispersive use production, which peaked in 2007. Thereafter in 2007-2009, incineration through CDM projects became a larger factor, reducing global HFC-23 emissions despite rapidly rising HCFC-22 feedstock production in developing countries.

Arnold, T, Ivy DJ, Harth CM, Vollmer MK, Muhle J, Salameh PK, Steele LP, Krummel PB, Wang RHJ, Young D, Lunder CR, Hermansen O, Rhee TS, Kim J, Reimann S, O'Doherty S, Fraser PJ, Simmonds PG, Prinn RG, Weiss RF.  2014.  HFC-43-10mee atmospheric abundances and global emission estimates. Geophysical Research Letters. 41:2228-2235.   10.1002/2013gl059143   AbstractWebsite

We report in situ atmospheric measurements of hydrofluorocarbon HFC-43-10mee (C5H2F10; 1,1,1,2,2,3,4,5,5,5-decafluoropentane) from seven observatories at various latitudes, together with measurements of archived air samples and recent Antarctic flask air samples. The global mean tropospheric abundance was 0.210.05ppt (parts per trillion, dry air mole fraction) in 2012, rising from 0.040.03ppt in 2000. We combine the measurements with a model and an inverse method to estimate rising global emissionsfrom 0.430.34Ggyr(-1) in 2000 to 1.130.31Ggyr(-1) in 2012 (similar to 1.9TgCO(2)-eqyr(-1) based on a 100year global warming potential of 1660). HFC-43-10meea cleaning solvent used in the electronics industryis currently a minor contributor to global radiative forcing relative to total HFCs; however, our calculated emissions highlight a significant difference from the available reported figures and projected estimates.

Petrenko, VV, Severinghaus JP, Smith AM, Riedel K, Baggenstos D, Harth C, Orsi A, Hua Q, Franz P, Takeshita Y, Brailsford GW, Weiss RF, Buizert C, Dickson A, Schaefer H.  2013.  High-precision 14C measurements demonstrate production of in situ cosmogenic 14CH4 and rapid loss of in situ cosmogenic 14CO in shallow Greenland firn. Earth and Planetary Science Letters. 365:190-197.   10.1016/j.epsl.2013.01.032   AbstractWebsite

Measurements of radiocarbon (C-14) in carbon dioxide (CO2), methane (CH4) and carbon monoxide (CO) from glacial ice are potentially useful for absolute dating of ice cores, studies of the past atmospheric CH4 budget and for reconstructing the past cosmic ray flux and solar activity. Interpretation of C-14 signals in ice is complicated by the fact that the two major C-14 components-trapped atmospheric and in situ cosmogenic-are present in a combined form, as well as by a very limited understanding of the in situ component. This study measured (CH4)-C-14 and (CO)-C-14 content in glacial firn with unprecedented precision to advance understanding of the in situ C-14 component. (CH4)-C-14 and (CO)-C-14 were melt-extracted on site at Summit, Greenland from three very large (similar to 1000 kg each) replicate samples of firn that spanned a depth range of 3.6-5.6 m. Non-cosmogenic C-14 contributions were carefully characterized through simulated extractions and a suite of supporting measurements. In situ cosmogenic (CO)-C-14 was quantified to better than +/- 0.6 molecules g(-1) ice, improving on the precision of the best prior ice (CO)-C-14 measurements by an order of magnitude. The (CO)-C-14 measurements indicate that most (>99%) of the in situ cosmogenic C-14 is rapidly lost from shallow Summit firn to the atmosphere. Despite this rapid C-14 loss, our measurements successfully quantified (CH4)-C-14 in the retained fraction of cosmogenic C-14 (to +/- 0.01 molecules g(-1) ice or better), and demonstrate for the first time that a significant amount of (CH4)-C-14 is produced by cosmic rays in natural ice. This conclusion increases the confidence in the results of an earlier study that used measurements of (CH4)-C-14 in glacial ice to show that wetlands were the likely main driver of the large and rapid atmospheric CH4 increase approximately 1 1.6 kyr ago. (C) 2013 Elsevier B.V. All rights reserved.

Meinshausen, M, Vogel E, Nauels A, Lorbacher K, Meinshausen N, Etheridge DM, Fraser PJ, Montzka SA, Rayner PJ, Trudinger CM, Krummel PB, Beyerle U, Canadell JG, Daniel JS, Enting IG, Law RM, Lunder CR, O'Doherty S, Prinn RG, Reimann S, Rubino M, Velders GJM, Vollmer MK, Wang RHJ, Weiss R.  2017.  Historical greenhouse gas concentrations for climate modelling (CMIP6). Geoscientific Model Development. 10:2057-2116.   10.5194/gmd-10-2057-2017   AbstractWebsite

Atmospheric greenhouse gas (GHG) concentrations are at unprecedented, record-high levels compared to the last 800 000 years. Those elevated GHG concentrations warm the planet and - partially offset by net cooling effects by aerosols - are largely responsible for the observed warming over the past 150 years. An accurate representation of GHG concentrations is hence important to understand and model recent climate change. So far, community efforts to create composite datasets of GHG concentrations with seasonal and latitudinal information have focused on marine boundary layer conditions and recent trends since the 1980s. Here, we provide consolidated datasets of historical atmospheric concentrations (mole fractions) of 43 GHGs to be used in the Climate Model Intercomparison Project Phase 6 (CMIP6) experiments. The presented datasets are based on AGAGE and NOAA networks, firn and ice core data, and archived air data, and a large set of published studies. In contrast to previous intercomparisons, the new datasets are latitudinally resolved and include seasonality. We focus on the period 1850-2014 for historical CMIP6 runs, but data are also provided for the last 2000 years. Weprovide consolidated datasets in various spatiotemporal resolutions for carbon dioxide (CO2), mcthanc (CH4) and nitrous oxide (N2O), as well as 40 other GHGs, namely 17 ozone-depleting substances, 11 hydrofluorocarbons (HFCs), 9 perfluorocarbons (PFCs), sulfur hexafluoride (SF6), nitrogen trifluoride (NF3) and sulfuryl fluoride (SO2F2). In addition we provide three equivalence species that aggregate concentrations of GHGs other than CO2, CH4 and N2O, weighted by their radiative forcing efficiencies. For the year 1850, which is used for pre-industrial control runs, we estimate annual global-mean surface concentrations of CO2 at 284.3 ppm, CH4 at 808.2 ppb and N2O at 273.0 ppb. The data are available at https://esgf-node.llnl.gov/search/input4mips/and www.climatecollege.unimelb.edu.au/cmip6. While the minimum CMIP6 recommendation is to use the global-and annual-mean time series, modelling groups can also choose our monthly and latitudinally resolved concentrations, which imply a stronger radiative forcing in the Northern Hemisphere winter (due to the latitudinal gradient and seasonality).

Rigby, M, Muhle J, Miller BR, Prinn RG, Krummel PB, Steele LP, Fraser PJ, Salameh PK, Harth CM, Weiss RF, Greally BR, O'Doherty S, Simmonds PG, Vollmer MK, Reimann S, Kim J, Kim KR, Wang HJ, Olivier JGJ, Dlugokencky EJ, Dutton GS, Hall BD, Elkins JW.  2010.  History of atmospheric SF6 from 1973 to 2008. Atmospheric Chemistry and Physics. 10:10305-10320.   10.5194/acp-10-10305-2010   AbstractWebsite

We present atmospheric sulfur hexafluoride (SF(6)) mole fractions and emissions estimates from the 1970s to 2008. Measurements were made of archived air samples starting from 1973 in the Northern Hemisphere and from 1978 in the Southern Hemisphere, using the Advanced Global Atmospheric Gases Experiment (AGAGE) gas chromatographic-mass spectrometric (GC-MS) systems. These measurements were combined with modern high-frequency GC-MS and GC-electron capture detection (ECD) data from AGAGE monitoring sites, to produce a unique 35-year atmospheric record of this potent greenhouse gas. Atmospheric mole fractions were found to have increased by more than an order of magnitude between 1973 and 2008. The 2008 growth rate was the highest recorded, at 0.29 +/- 0.02 pmol mol(-1) yr(-1). A three-dimensional chemical transport model and a minimum variance Bayesian inverse method was used to estimate annual emission rates using the measurements, with a priori estimates from the Emissions Database for Global Atmospheric Research (EDGAR, version 4). Consistent with the mole fraction growth rate maximum, global emissions during 2008 were also the highest in the 1973-2008 period, reaching 7.4 +/- 0.6 Gg yr(-1) (1-sigma uncertainties) and surpassing the previous maximum in 1995. The 2008 values follow an increase in emissions of 48 +/- 20% since 2001. A second global inversion which also incorporated National Oceanic and Atmospheric Administration (NOAA) flask measurements and in situ monitoring site data agreed well with the emissions derived using AGAGE measurements alone. By estimating continent-scale emissions using all available AGAGE and NOAA surface measurements covering the period 2004-2008, with no pollution filtering, we find that it is likely that much of the global emissions rise during this five-year period originated primarily from Asian developing countries that do not report detailed, annual emissions to the United Nations Framework Convention on Climate Change (UNFCCC). We also find it likely that SF(6) emissions reported to the UNFCCC were underestimated between at least 2004 and 2005.

Prinn, RG, Weiss RF, Arduini J, Arnold T, DeWitt HL, Fraser PJ, Ganesan AL, Gasore J, Harth CM, Hermansen O, Kim J, Krummel PB, Li SL, Loh ZM, Lunder CR, Maione M, Manning AJ, Miller B, Mitrevski B, Muhle J, O'Doherty S, Park S, Reimann S, Rigby M, Saito T, Salameh PK, Schmidt R, Simmonds PG, Steele LP, Vollmer MK, Wang RH, Yao B, Yokouchi Y, Young D, Zhou LX.  2018.  History of chemically and radiatively important atmospheric gases from the Advanced Global Atmospheric Gases Experiment (AGAGE). Earth System Science Data. 10:985-1018.   10.5194/essd-10-985-2018   AbstractWebsite

We present the organization, instrumentation, datasets, data interpretation, modeling, and accomplishments of the multinational global atmospheric measurement program AGAGE (Advanced Global Atmospheric Gases Experiment). AGAGE is distinguished by its capability to measure globally, at high frequency, and at multiple sites all the important species in the Montreal Protocol and all the important non-carbon-dioxide (non-CO2) gases assessed by the Intergovernmental Panel on Climate Change (CO2 is also measured at several sites). The scientific objectives of AGAGE are important in furthering our understanding of global chemical and climatic phenomena. They are the following: (1) to accurately measure the temporal and spatial distributions of anthropogenic gases that contribute the majority of reactive halogen to the stratosphere and/or are strong infrared absorbers (chlorocarbons, chlorofluorocarbons CFCs, bromocarbons, hydrochlorofluorocarbons HCFCs, hydrofluorocarbons HFCs and polyfluorinated compounds (perfluorocarbons PFCs), nitrogen trifluoride NF3, sulfuryl fluoride SO2F2, and sulfur hexafluoride SF6) and use these measurements to determine the global rates of their emission and/or destruction (i.e., lifetimes); (2) to accurately measure the global distributions and temporal behaviors and determine the sources and sinks of non-CO2 biogenic anthropogenic gases important to climate change and/or ozone depletion (methane CH4, nitrous oxide N20, carbon monoxide CO, molecular hydrogen H2, methyl chloride CH3C1, and methyl bromide CH3Br); (3) to identify new long-lived greenhouse and ozone -depleting gases (e.g., SO2F2, NF3, heavy PFCs (C4Fm, C5F12, C6F 14, C7F16, and C8F18) and hydrofluoroolefins (HF0s; e.g., CH2 = CFCF3) have been identified in AGAGE), initiate the real-time monitoring of these new gases, and reconstruct their past histories from AGAGE, air archive, and firn air measurements; (4) to determine the average concentrations and trends of tropospheric hydroxyl radicals (OH) from the rates of destruction of atmospheric trichloroethane (CH3CC13), HFCs, and HCFCs and estimates of their emissions; (5) to determine from atmospheric observations and estimates of their destruction rates the magnitudes and distributions by region of surface sources and sinks of all measured gases; (6) to provide accurate data on the global accumulation of many of these trace gases that are used to test the synoptic-, regional-, and global -scale circulations predicted by three-dimensional models; and (7) to provide global and regional measurements of methane, carbon monoxide, and molecular hydrogen and estimates of hydroxyl levels to test primary atmospheric oxidation pathways at midlatitudes and the tropics. Network Information and Data Repository: http://agage.mit.edu/data or http://cdiac.ess-dive.lbl.gov/ndps/alegage.html (https://doi.org/10.3334/CDIAC/atg.db1001).

Prinn, RG, Weiss RF, Fraser PJ, Simmonds PG, Cunnold DM, Alyea FN, O'Doherty S, Salameh P, Miller BR, Huang J, Wang RHJ, Hartley DE, Harth C, Steele LP, Sturrock G, Midgley PM, McCulloch A.  2000.  A history of chemically and radiatively important gases in air deduced from ALE/GAGE/AGAGE. Journal of Geophysical Research-Atmospheres. 105:17751-17792.   10.1029/2000jd900141   AbstractWebsite

We describe in detail the instrumentation and calibrations used in the Atmospheric Lifetime Experiment (ALE), the Global Atmospheric Cases Experiment (GAGE), and the Advanced Global Atmospheric Gases Experiment (AGAGE) and present a history of the majority of the anthropogenic ozone-depleting and climate-forcing gases in air based on these experiments. Beginning in 1978, these three successive automated high-frequency in situ experiments have documented the long-term behavior of the measured concentrations of these gases over the past 20 years, and show both the evolution of latitudinal gradients and the high-frequency variability due to sources and circulation. We provide estimates of the long-term trends in total chlorine contained in long-lived halocarbons involved in ozone depletion. We summarize interpretations of these measurements using inverse methods to determine trace gas lifetimes and emissions. Finally, we provide a combined observational and modeled reconstruction of the evolution of chlorocarbons by latitude in the atmosphere over the past 60 years which can be used as boundary conditions for interpreting trapped air in glaciers and oceanic measurements of chlorocarbon tracers of the deep oceanic circulation. Some specific conclusions are as follows: (1) International compliance with the Montreal Protocol is so far resulting in chlorofluorocarbon and chlorocarbon mole fractions comparable to target levels; (2) mole fractions of total chlorine contained in long-lived halocarbons (CCl2F2, CCl3F, CH3CCl3, CCl4, CHClF2, CCl2FCClF2, CH3Cl, CH2Cl2, CHCl3, CCl2=CCl2) in the lower troposphere reached maximum values of about 3.6 ppb in 1993 and are beginning to slowly decrease in the global lower atmosphere; (3) the chlorofluorocarbons have atmospheric lifetimes consistent with destruction in the stratosphere being their principal removal mechanism; (4) multiannual variations in chlorofluorocarbon and chlorocarbon emissions deduced from ALE/GAGE/AGAGE data are consistent approximately with variations estimated independently from industrial production and sales data where available (CCl2F2 (CFC-12) and CCl2FCClF2 (CFC-113) show the greatest discrepancies); (5) the mole fractions of the hydrochlorofluorocarbons and hydrofluorocarbons, which are replacing the regulated halocarbons, are rising very rapidly in the atmosphere, but with the exception of the much longer manufactured CHClF2 (HCFC-22), they are not yet at levels sufficient to contribute significantly to atmospheric chlorine loading. These replacement species could in the future provide independent estimates of the global weighted-average OH concentration provided their industrial emissions are accurately documented; (6) in the future, analysis of pollution events measured using high-frequency in situ measurements of chlorofluorocarbons and their replacements may enable emission estimates at the regional level, which, together with industrial end-use data, are of sufficient accuracy to he capable of identifying regional noncompliance with the Montreal Protocol.

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.

Stohl, A, Kim J, Li S, O'Doherty S, Muhle J, Salameh PK, Saito T, Vollmer MK, Wan D, Weiss RF, Yao B, Yokouchi Y, Zhou LX.  2010.  Hydrochlorofluorocarbon and hydrofluorocarbon emissions in East Asia determined by inverse modeling. Atmospheric Chemistry and Physics. 10:3545-3560.   10.5194/acp-10-3545-2010   AbstractWebsite

The emissions of three hydrochlorofluorocarbons, HCFC-22 (CHClF(2)), HCFC-141b (CH(3)CCl(2)F) and HCFC-142b (CH(3)CClF(2)) and three hydrofluorocarbons, HFC-23 (CHF(3)), HFC-134a (CH(2)FCF(3)) and HFC-152a (CH(3)CHF(2)) from four East Asian countries and the Taiwan region for the year 2008 are determined by inverse modeling. The inverse modeling is based on in-situ measurements of these halocarbons at the Japanese stations Cape Ochi-ishi and Hateruma, the Chinese station Shangdianzi and the South Korean station Gosan. For every station and every 3 h, 20-day backward calculations were made with the Lagrangian particle dispersion model FLEXPART. The model output, the measurement data, bottom-up emission information and corresponding uncertainties were fed into an inversion algorithm to determine the regional emission fluxes. The model captures the observed variation of halocarbon mixing ratios very well for the two Japanese stations but has difficulties explaining the large observed variability at Shangdianzi, which is partly caused by small-scale transport from Beijing that is not adequately captured by the model. Based on HFC-23 measurements, the inversion algorithm could successfully identify the locations of factories known to produce HCFC-22 and emit HFC-23 as an unintentional byproduct. This lends substantial credibility to the inversion method. We report national emissions for China, North Korea, South Korea and Japan, as well as emissions for the Taiwan region. Halocarbon emissions in China are much larger than the emissions in the other countries together and contribute a substantial fraction to the global emissions. Our estimates of Chinese emissions for the year 2008 are 65.3 +/- 6.6 kt/yr for HCFC-22 (17% of global emissions extrapolated from Montzka et al., 2009), 12.1 +/- 1.6 kt/yr for HCFC-141b (22%), 7.3 +/- 0.7 kt/yr for HCFC-142b (17%), 6.2 +/- 0.7 kt/yr for HFC-23 (> 50%), 12.9 +/- 1.7 kt/yr for HFC-134a (9% of global emissions estimated from Velders et al., 2009) and 3.4 +/- 0.5 kt/yr for HFC-152a (7%).

Weiss, RF.  1977.  Hydrothermal manganese in the deep sea: Scavenging residence time and Mn/3He relationships. Earth and Planetary Science Letters. 37:257-262.   10.1016/0012-821x(77)90171-6   AbstractWebsite

Measurements of hydrothermal Mn in the water column overlying the Galapagos Rift have been fitted to a one-dimensional first-order scavenging model. Assuming a vertical advection velocity of 4 m/yr, the model gives a scavenging residence time for Mn of 51 years. The horizontal propagation distance for hydrothermal Mn in the water column is thus estimated to be on the order of 1000 km. The Mg/3He injection ratios for the Galapagos Rift hydrothermal plume samples and the Red Sea brines are in close agreement. The Mn flux determined from the scavenging model and the estimates of Mn flux based on the Mg/3He injection ratio are compared to the Mn accumulation rates observed in deep-sea sediments.

Klinkhammer, G, Bender M, Weiss RF.  1977.  Hydrothermal manganese in the Galapagos Rift. Nature. 269:319-320.   10.1038/269319a0   AbstractWebsite

HYDROTHERMAL emanations originating at mid-ocean ridges have been thought1–5 to provide a substantial source of manganese to the ocean but the evidence supporting this hypothesis has been indirect. Anomalous manganese concentrations have been measured in naturally occurring systems where seawater is in direct contact with lava flows6–8. Laboratory studies have shown that seawater tends to leach manganese from basalts at elevated temperatures and pressures9–11. Anomalously high manganese accumulation rates have also been determined for sediments adjacent to active ridge systems, most notably the East Pacific Rise12–14. No measurements of manganese concentrations in seawater near mid-ocean ridges, or in hydrothermal fluids emanating from these ridges, have yet been made, however. We report here the results of the first such direct measurements, which show that manganese is being injected into the deep sea by hydrothermal circulation of seawater through newly-formed oceanic crust.

Weiss, RF, Lonsdale P, Lupton JE, Bainbridge AE, Craig H.  1977.  Hydrothermal plumes in the Galapagos Rift. Nature. 267:600-603.   10.1038/267600a0   AbstractWebsite

ALTHOUGH there is indirect evidence that a major fraction of the heat loss from newly-created lithosphere occurs by convection of seawater through the porous crust1–3, it has proved difficult to locate vents of deep-sea hydrothermal systems by direct measurement of the discharge fluid. Local increases in bottom water temperature up to 0.1 °C have been measured by towing arrays of thermistors a few metres above the axes of active oceanic spreading centres4,5, but these data are ambiguous because small temperature anomalies may have a hydrographic explanation. We report here the first conclusive measurements of modified seawater discharging as buoyant hydrothermal plumes from fissures in young oceanic crust. We obtained samples of hydrothermal plumes in the Galapagos Rift3, albeit after considerable dilution with surrounding bottom-water, and report the first results of the collection and analysis of these samples.