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Falkner, KK, Measures CI, Herbelin SE, Edmond JM, Weiss RF.  1991.  The major and minor element geochemistry of Lake Baikal. Limnology and Oceanography. 36:413-423. AbstractWebsite

A comprehensive, joint Soviet-American study of the chemistry of Lake Baikal, the world's deepest (1,632 m) lake, was carried out in July 1988. In this paper, we report the major, minor, and preliminary trace element concentrations for three profiles obtained at or near the deepest and central part of the three major basins of the lake. With the exception of Ba, the distributions of major and minor elements were homogeneous, displaying no variations greater than analytical uncertainties. Average concentrations in mu-mol kg-1 (1 SD) are titration alkalinity = 1,093(6), SO42- = 57.4(1.3), Cl = 12.3(0.7), Ca = 402(7), Mg = 126(1), Na = 155(4), and K = 24.1(1.0); and in nmol kg-1 are Sr = 1,350(30), Li = 296(12), Ba = 74.7(2.6), Rb = 7.10(0.23), and U = 1.77(0.12). Excluding K and Cl, these values compare favorably with previously published results. Although some hydrothermal activity is known to occur within the lake, it does not appear to significantly affect major ion cycling. The residence times of the major ions are 330 yr or the same as that of water in the basin and so are controlled predominantly by their riverine fluxes. There is not yet enough information to assess whether hydrothermal processes affect minor element cycles. Ba concentrations decrease with depth, showing abrupt decreases near the bottom at two stations. It appears to undergo some form of uptake at the sediments, but further study is required to discern the processes governing Ba distribution.

Fang, XK, Park S, Saito T, Tunnicliffe R, Ganesan AL, Rigby M, Li SL, Yokouchi Y, Fraser PJ, Harth CM, Krummel PB, Muhle J, O'Doherty S, Salameh PK, Simmonds PG, Weiss RF, Young D, Lunt MF, Manning AJ, Gressentl A, Prinn RG.  2019.  Rapid increase in ozone-depleting chloroform emissions from China. Nature Geoscience. 12:89-+.   10.1038/s41561-018-0278-2   AbstractWebsite

Chloroform contributes to the depletion of the stratospheric ozone layer. However, due to its short lifetime and predominantly natural sources, it is not included in the Montreal Protocol that regulates the production and uses of ozone-depleting substances. Atmospheric chloroform mole fractions were relatively stable or slowly decreased during 1990-2010. Here we show that global chloroform mole fractions increased after 2010, based on in situ chloroform measurements at seven stations around the world. We estimate that the global chloroform emissions grew at the rate of 3.5% yr(-1) between 2010 and 2015 based on atmospheric model simulations. We used two regional inverse modelling approaches, combined with observations from East Asia, to show that emissions from eastern China grew by 49 (41-59) Gg between 2010 and 2015, a change that could explain the entire increase in global emissions. We suggest that if chloroform emissions continuously grow at the current rate, the recovery of the stratospheric ozone layer above Antarctica could be delayed by several years.

Fine, RA, Smethie WM, Bullister JL, Rhein M, Min DH, Warner MJ, Poisson A, Weiss RF.  2008.  Decadal ventilation and mixing of Indian Ocean waters. Deep-Sea Research Part I-Oceanographic Research Papers. 55:20-37.   10.1016/j.dsr.2007.10.002   AbstractWebsite

Chlorofluorocarbon (CFC) and hydrographic data from the World Ocean Circulation Experiment (WOCE) Indian Ocean expedition are used to evaluate contributions to decadal ventilation of water masses. At a given density, CFC-derived ages increase and concentrations decrease from the south to north, with lowest concentrations and oldest ages in Bay of Bengal. Average ages for thermocline water are 0-40 years, and for intermediate water they are less than 10 years to more than 40 years. As compared with the marginal seas or throughflow, the most significant source of CFCs for the Indian Ocean south of 12 degrees N is the Southern Hemisphere. A simple calculation is used to show this is the case even at intermediate levels due to differences in gas solubilities and mixing of Antarctic Intermediate Water and Red Sea Water. Bottom water in the Australia-Antarctic Basin is higher in CFC concentrations than that to the west in the Enderby Basin, due to the shorter distance of this water to the Adelie Land coast and Ross Sea sources. However, by 40 degrees S, CFC concentrations in the bottom water of the Crozet Basin originating from the Weddell Sea are similar to those in the South Australia Basin. Independent observations, which show that bottom water undergoes elevated mixing between the Australia-Antarctic Basin and before entering the subtropics, are consistent with high CFC dilutions (3-14-fold) and a substantial concentration decrease (factor of 5) south to north of the Southeast Indian Ridge. CFC-bearing bottom waters with ages 30 years or more are transported into the subtropical South Indian Ocean by three western boundary currents, and highest concentrations are observed in the westernmost current. During WOCE, CFC-bearing bottom water reaches to about 30 degrees S in the Perth Basin, and to 20 degrees S in the Mascarene Basin. Comparing subtropical bottom water-CFC concentrations with those of the South Pacific and Atlantic oceans, at comparable latitudes, Indian Ocean bottom water-CFC concentrations are lower, consistent with its high dissipation rates from tidal mixing and current fluctuations as shown elsewhere. Thus, the generally high dilutions and low CFC concentrations in bottom water of the Indian Ocean are due to distance to the water mass source regions and the relative effectiveness of mixing. While it is not surprising that at thermocline, intermediate, and bottom levels, the significant ventilation sources on decadal time scales are all from the south, the CFCs show how local sources and mixing within the ocean affect the ventilation. (c) 2007 Elsevier Ltd. All rights reserved.

Fine, RA, Warner MJ, Weiss RF.  1988.  Water mass modification at the Agulhas retroflection: chlorofluoromethane studies. Deep-Sea Research Part a-Oceanographic Research Papers. 35:311-332.   10.1016/0198-0149(88)90013-1   AbstractWebsite

Chlorofluoromethane (CFM) and hydrographic data from the 1983 Agulhas Retroflection cruise are used to show the importance of the region in ventilating thermocline and Intermediate Waters of the southwest Indian ocean gyre. Generally South Atlantic waters are more recently ventilated by at least two years than those of the South Indian Ocean, probably because the latter are farther downstream from the source regions near the South Atlantic subantarctic sector. A two-component mixing model shows that the outflow from the Agulhas Retroflection (14-4°C) was composed of South Indian water and at least 23% South Atlantic water. However, at the density of Indian sector Subantarctic Mode Water the inflow into the Agulhas Retroflection was well preserved in the outflow, and the South Atlantic and Indian waters appear to be ventilated by different water masses. In addition, strong interleaving was found throughout the survey area (between 14 and 4°C), characterized by correlations of negative salinity anomalies with high CFM concentrations. At the density of Antarctic Intermediate Water (AAIW) there was interleaving of both low salinity water and higher salinity Red Sea Water. Using estimates of past atmospheric ratios of two CFMs, we calculate that AAIW within the retroflection was 50–75% diluted by mixing with CFM-free water since leaving the source region. Results from the two-component mixing model, which show substantial contributions of South Atlantic water in the outflow, suggest that the return flow for the 10 Sv leakage of Indian Ocean water via the Agulhas Current into the South Atlantic [Gordon (1985) Science, 227, 1030–1033; Gordonet al. (1987) Deep-Sea Research, 34, 565–600] is occurring at thermocline and intermediate depths. A combination of active mixing in this region and similarity in the ventilation processes may be the reason that the South Atlantic and Indian thermoclines are coincident in temperature and salinity space (between 15 and 7°C) as noted by Gordon.

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.

Fortems-Cheiney, A, Saunois M, Pison I, Chevallier F, Bousquet P, Cressot C, Montzka SA, Fraser PJ, Vollmer MK, Simmonds PG, Young D, O'Doherty S, Weiss RF, Artuso F, Barletta B, Blake DR, Li S, Lunder C, Miller BR, Park S, Prinn R, Saito T, Steele LP, Yokouchi Y.  2015.  Increase in HFC-134a emissions in response to the success of the Montreal Protocol. Journal of Geophysical Research-Atmospheres. 120   10.1002/2015jd023741   AbstractWebsite

The 1,1,1,2-tetrafluoroethane (HFC-134a), an important alternative to CFC-12 in accordance with the Montreal Protocol on Substances that Deplete the Ozone Layer, is a high global warming potential greenhouse gas. Here we evaluate variations in global and regional HFC-134a emissions and emission trends, from 1995 to 2010, at a relatively high spatial and temporal (3.75 degrees in longitude x 2.5 degrees in latitude and 8 day) resolution, using surface HFC-134a measurements. Our results show a progressive increase of global HFC-134a emissions from 19 +/- 2 Gg/yr in 1995 to 167 +/- 5 Gg/yr in 2010, with both a slowdown in developed countries and a 20%/yr increase in China since 2005. A seasonal cycle is also seen since 2002, which becomes enhanced over time, with larger values during the boreal summer.

Fraser, PJ, Dunse BL, Manning AJ, Walsh S, Wang HRJ, Krummel PB, Steele PL, Porter LW, Allison C, O’Doherty S, Simmonds PG, Mühle J, Weiss RF, Prinn RG.  2014.  Australian carbon tetrachloride emissions in a global context. Environmental Chemistry. 11:77-88.   10.1071/EN13171   AbstractWebsite

Global (1978–2012) and Australian (1996–2011) carbon tetrachloride emissions are estimated from atmospheric observations of CCl4 using data from the Advanced Global Atmospheric Gases Experiment (AGAGE) global network, in particular from Cape Grim, Tasmania. Global and Australian emissions are in decline in response to Montreal Protocol restrictions on CCl4 production and consumption for dispersive uses in the developed and developing world. However, atmospheric data-derived emissions are significantly larger than ‘bottom-up’ estimates from direct and indirect CCl4 production, CCl4 transportation and use. Australian CCl4 emissions are not a result of these sources, and the identification of the origin of Australian emissions may provide a clue to the origin of some of these ‘missing’ global sources.

Fraser, P, Cunnold D, Alyea F, Weiss R, Prinn R, Simmonds P, Miller B, Langenfelds R.  1996.  Lifetime and emission estimates of 1,1,2-trichlorotrifluorethane (CFC-113) from daily global background observations June 1982 June 1994. Journal of Geophysical Research-Atmospheres. 101:12585-12599.   10.1029/96jd00574   AbstractWebsite

Observations every two hours of CCl2FCClF2 at Mace Head, Ireland (February 1987-June 1994); Cape Meares, Oregon (April 1984-June 1989); Ragged Point, Barbados (October 1985-June 1994); Cape Matatula, Samoa (October 1985-June 1989 and January 1992-June 1994); and Cape Grim, Tasmania (June 1982-June 1994) are reported, The observations from Cape Grim have been extended back to 1978 using archived air samples. The global atmospheric abundance of CCl2FCClF2 is indicated to have been growing exponentially between 1978 and 1987 with an e-folding time of approximately 7.6 years; it has been growing less rapidly since that time. On January 1, 1994, the mean inferred northern hemispheric mixing ratio in the lower troposphere was 84.4 +/- 0.4 ppt and the southern hemispheric value was 80.6 +/- 0.4 ppt; the global growth rate in 1991-1993 is estimated to have averaged approximately 3.1 +/- 0.1 ppt/year. The differences between the northern and southern hemispheric concentrations are calculated to be consistent with the almost entirely northern hemispheric release of this gas. The annual release estimates of CCl2FCClF2 by industry, which include estimates of eastern European emissions, fairly consistently exceed those deduced from the measurements by approximately 10% from 1980 to 1993. The uncertainties in each estimate is approximately 5%. This difference suggests that up to 10% of past production might not yet have been released. The measurements indicate that atmospheric releases of CCl2FCClF2 have been decreasing rapidly since 1989 and in 1993 amounted to 78 +/- 27 x 10(6) kg or 42 +/- 15% of the 1985-1987 emissions.

Fraser, A, Palmer PI, Feng L, Boesch H, Cogan A, Parker R, Dlugokencky EJ, Fraser PJ, Krummel PB, Langenfelds RL, O'Doherty S, Prinn RG, Steele LP, van der Schoot M, Weiss RF.  2013.  Estimating regional methane surface fluxes: the relative importance of surface and GOSAT mole fraction measurements. Atmospheric Chemistry and Physics. 13:5697-5713.   10.5194/acp-13-5697-2013   AbstractWebsite

We use an ensemble Kalman filter (EnKF), together with the GEOS-Chem chemistry transport model, to estimate regional monthly methane (CH4) fluxes for the period June 2009-December 2010 using proxy dry-air column-averaged mole fractions of methane (XCH4) from GOSAT (Greenhouse gases Observing SATellite) and/or NOAA ESRL (Earth System Research Laboratory) and CSIRO GASLAB (Global Atmospheric Sampling Laboratory) CH4 surface mole fraction measurements. Global posterior estimates using GOSAT and/or surface measurements are between 510-516 Tg yr(-1), which is less than, though within the uncertainty of, the prior global flux of 529 +/- 25 Tg yr(-1). We find larger differences between regional prior and posterior fluxes, with the largest changes in monthly emissions (75 Tg yr(-1)) occurring in Temperate Eurasia. In non-boreal regions the error reductions for inversions using the GOSAT data are at least three times larger (up to 45 %) than if only surface data are assimilated, a reflection of the greater spatial coverage of GOSAT, with the two exceptions of latitudes >60 degrees associated with a data filter and over Europe where the surface network adequately describes fluxes on our model spatial and temporal grid. We use CarbonTracker and GEOS-Chem XCO2 model output to investigate model error on quantifying proxy GOSAT XCH4 (involving model XCO2) and inferring methane flux estimates from surface mole fraction data and show similar resulting fluxes, with differences reflecting initial differences in the proxy value. Using a series of observing system simulation experiments (OSSEs) we characterize the posterior flux error introduced by non-uniform atmospheric sampling by GOSAT. We show that clear-sky measurements can theoretically reproduce fluxes within 10% of true values, with the exception of tropical regions where, due to a large seasonal cycle in the number of measurements because of clouds and aerosols, fluxes are within 15% of true fluxes. We evaluate our posterior methane fluxes by incorporating them into GEOS-Chem and sampling the model at the location and time of surface CH4 measurements from the AGAGE (Advanced Global Atmospheric Gases Experiment) network and column XCH4 measurements from TCCON (Total Carbon Column Observing Network). The posterior fluxes modestly improve the model agreement with AGAGE and TCCON data relative to prior fluxes, with the correlation coefficients (r(2)) increasing by a mean of 0.04 (range: -0.17 to 0.23) and the biases decreasing by a mean of 0.4 ppb (range: -8.9 to 8.4 ppb).

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