Climate Journal Club Home Page

Note (October 2004): Due to the demands of our upcoming field mission, and the attrition of core participants to faculty positions (congratulations, Anitra, Scott, Becky, and Dylan!), Climate Club is on hiatus. To pick it up again, contact moyer@huarp.harvard.edu for web page and email list write permission. --- Liz

Climate Journal Club

The EPS/Chemistry/DEAS climate journal club is a group meeting roughly every two weeks to discuss a recent paper or set of papers on a topic of relevance to climate and the earth system. (This broad span includes atmospheric and ocean sciences, biogeochemistry, and ecology.) The papers are chosen by members who volunteer to lead a discussion. Because the journal club's goal is helping us become familiar with current interesting research in many fields, we'll emphasize recent work over review articles. The journal club is also meant to bring together people with similar interests who are spread between the various departments and foster cross-department interactions.

Meetings will be generally held every other Thursday from noon-1 PM, but see the schedule below for exact dates. Meeting times may be skipped for holidays or added because of relevant visitors at Harvard. Unless otherwise noted, meetings are held in Museum 105 (the Daly seminar room, on the first floor of the Geological Museum, at 24 Oxford St.). The full journal club schedule is given below. As papers are chosen they will be posted here for downloading in pdf format; generally papers will be listed at least a week before each discussion. Although some weeks' listings will include several papers, we'll try to denote which is the most important and which are more optional background for those who want to go into the subject in more depth. To keep discussions strong we’d like regular participants to prepare solidly most weeks, but do feel free to come and listen even when you have only skimmed.

To subscribe to or unsubscribe from the climate journal club email list, fill out the form at the bottom of this page. To suggest papers, volunteer to lead a discussion, or otherwise give comments/feedback, write to owner-climatejclub@huarp.harvard.edu, or to one of the discussion leaders whose session is still listed as TBD.

Journal club schedule:

Date Topic Papers Leader Notes
Thursday Oct. 21 (note room change: Museum 202) Multiply-substituted isotopologues
  1. 18O13C16O in the atmosphere Eiler, J.M. & E. Schauble. Geochimica et Cosmochimica Acta, in preparation, 2004
  2. Equilibrium thermodynamics of multiply-subsituted isotopologues of molecular gases. Wang, Z., Schauble, E., & Eiler, J.M. manuscript, in preparation, 2004
  3. Figures for "Equilibrium thermodynamics of multiply-subsituted isotopologues of molecular gases." Wang, Z., Schauble, E., & Eiler, J.M. In preparation, 2004
Scott Saleska Not even on the presses yet: here are preprints of several articles from John Eiler's group laying out the physics of multi-atom isotopic subsitutions. Amazingly, a half-century after the Urey years there is still new fundamental isotope physics to be described and discovered. These papers are motivated by the improvements in measurement sensitivity that make measurement of multiply-substituted isotopologues now possible. We'll focus on the first paper (Eiler & Schauble), which is empirically oriented, rather than the second, more theoretical one
Thursday July 1 Michael Mann/ Soon & Baliunas controversy on temperatures during the Medieval Warm Period.
  1. Observed Climate Variability & Change. Intergovernmental Panel on Climate Change, 2001
  2. Proxy climatic and environmental changes of the past 1000 years Soon, W. and S. Baliunas. Climate Research, 23, p. 89-110, 2003
  3. On past temperatures and anomalous late-20th century warmth Mann, M. Eos, 84, p.1, 2003
  4. Storm brews over global warming Monastersky, R. Chronicle of Higher Education, Sept. 2003
Loretta Mickley The most famous image of the last IPCC report was Michael Mann's "hockey-stick" plot, showing fairly stable Northern Hemisphere temperatures through the last 1000 years, followed by rapid warming during the 20th century. A couple years later, Harvard-Smithsonian researchers Willie Soon and Sallie Baliunas made headllines with a study claiming that the Middle Ages were in fact much warmer than the Michael Mann plot implied. What was the controversy about? And why did did four editors from a relatively obscure journal resign in the aftermath?
The papers are: 1. Section in IPCC 2001 discussing climate over the last 1000 years. 2. One of the Soon/Baliunas papers from 2003. 3. Michael Mann et al.'s response in EOS in 2003. 4. An article in the Chronicle of Higher Education summarizing the controversy, again from 2003
Thursday June 10 Biomass burning and its influence on cloudiness
  1. Smoking rain clouds over the Amazon Andreae, M.O. et al. Science, 303, 1337, 2004
  2. Measurement of the effect of Amazon smoke on the inhibition of cloud formation Koren, I. et al. Science, 303, 1342, 2004
  3. Smoke From Burning Vegetation Changes the Coverage and Behavior of Clouds Day, C. Physics Today, May 2004
 Paul Palmer Do aerosols promote or inhibit cloud formation? The answer might be: "it depends". The two Science artices here describe in-situ and satellite observations of the effects of forest fires on cloud formation, one paper showing reduced cloud cover and the other stronger convection in the presence of smoke. The last article is a summary in Physics Today.
Thursday May 27 Determination of water vapor feedbacks in climate models
  1. Suppresion of ENSO in a coupled model without water vapor feedback. Hall, A., and S. Manabe. Climate Dynamics 16:393, 2000
  2. Suppresion of ENSO in a coupled model without water vapor feedback. Hall, A., and S. Manabe. J. Climate 12, p. 2327, 1999
Steve Leroy We'll concentrate on the first paper. Steve was at Caltech & JPL and has just arrived at Harvard as a researcher associated with the Anderson group
Tuesday May 11 (note date change) Possible effect of leaking hydrogen fuel on tropospheric chemistry
  1. Impact of a hydrogen economy on the stratosphere and troposphere studied in a 2-D model Warwick NJ, Bekki S, Nisbet EG, Pyle JA. GEOPHYSICAL RESEARCH LETTERS 31 (5), MAR 4 2004
 Fok-Yan Leung This is a continuation of Fok's discussion of Dec. 18. At that meeting we decided that the effects of hydrogen enhancement on stratospheric water were not large enough to be particularly frightening, and that the most most interesting potential effect of H2 leakage was on the oxidizing potential of the troposphere. "Someone should model that!" we said, and sure enough someone has.
Tuesday April 27 (note date change) Continuation of the LPTM discussion
  1. Coupling the geochemical cycles of C, P, Fe and S: The effect on Atmospheric O2 and the Isotopic records of carbon and sulfur Petsch S. and Berner R.A., American Journal of Science Vol. 298, pp. 246-262, 1998
  2. Fossil plants as indicators of the phanerozoic global carbon cycle Beerling, D.J. and D.L. Royer. Annu. Rev. Earth & Planet. Sci. 30:527–56, 2002
 Sasha Turchyn, John Higgins We are continuing the discussion of the LPTM with a discussion of the carbon and sulfur cycles over Earth's history. Dave Beerling is visiting & will attend this session. We'll refer to the Kurtz & Dickens papers from last session. The first paper discusses why people feel that the carbon and sulfur cycles should be coupled over long time periods in Earth's history. The second paper, by Beerling and Royer, discusses the use of fossil plants to reconstruct levels of CO2. The hope is that by discussing long term carbon cycles, CO2, and sulfur cycles, we will be better prepared to address the transient warming at the LPTM
Tuesday April 13 (note date change) The Late Paleocene Thermal Maximum
  1. Dissociation of oceanic methane hydrate as a cause of the carbon isotope excursion at the end of the Paleocene Dickens, G.R. et al. Paleoceanography 10, p. 965, 1995
  2. Mechanisms of climate warming at the end of the Paleocene Bains, S., R.M. Corfield, and R.D. Norris. Science 285, p. 724, 1999
  3. A transient rise in tropical sea surface temperature during the Paleocene-Eocene thermal maximum Zachos, J.C. et al. Science 302, p. 1551, 2003
  4. Early Cenozoic decoupling of the global carbon and sulfur cycles Kurtz, A.C. et al. Paleoceanography 18, p. 14, 2003
  5. An Earth on fire Weissert, H. and S.M. Bernasconi. Nature (News & Views) 428, p. 130, 2004
 Sasha Turchyn These papers all discuss the severe temperature rise that occurred 55 million years ago at the end of the Paleocene, and the accompanying change in carbonate isotopic composition. If you do not have time to read them all: first read paper #1 (Dickens), which proposed that the isotopic shift (and warming?) was due to a massive release of methane from hydrates. Then skim #4 (Kurtz) or read #5, the News & Views on it, for a rival theory: Kurtz et al. think the isotopic shift (and warming?) was due to CO2 released by huge wildfires that burned accumulated peat.
Thursday Apr. 1 Burial of black carbon in ocean sediments
  1. Reburial of fossil organic carbon in marine sediments Dickens, A.F. et al. Nature 427, p. 336, 2004
  2. Black carbon in deep-sea sediments Masiello, C.A. and E.R.M. Druffel. Science 280, p. 1911, 1998
  3. News and Views article on Masiello & DruffelKuhlbusch, T.A.J., Science News, 1998
  4. Final Recommendations for Reference Materials in Black Carbon Analysis. Schmidt, M.W.I. EOS 23 Meeting Report, 2003
  5. 14C-dead living biomass: evidence for microbial assimilation of ancient organic carbon during shale weathering Petsch, S.T. et al. Science 292, p. 1127, 2001
  6. Variability in radiocarbon ages of individual organic compounds from marine sediments Eglinton, T.I. et al. Science 277, p. 796, 1997
 Anitra Ingalls Papers 1 & 2 are about the quantification and radiocarbon dating of black carbon in marine sediments. These are what we'll be discussing. Paper 3 is a news-and-views on paper 2. The rest are optional background material. Paper 4 is a committee report; it's there to point out that there are serious methodological issues related to quantifying black carbon that have created some controversy. Papers 5 & 6 are further background material about dating black carbon in sediments.
Thursday Mar. 18 Finding the fingerprint of human climate influence in temperature data
  1. Discriminants of Twentieth-Century Changes in Earth Surface Temperatures Schneider, T. and I.M. Held. J. Climate, 14, p. 249, 2001
  2. A search for human influences on the thermal structure of the atmosphere Santer, B.D. et al. Nature 382, p. 39, 1996
  3. The 1995 IPCC Report: Broad Consensus or "Scientific Cleansing"? Edwards, P.N. and S.H. Schneider. Ecofables/Ecoscience 1:1, p. 3, 1997
 Liz Moyer The Schneider 2001 paper is a critique of methods used in Santer et al. 1996, which itself is a recap of chapter 8 from the 1995 IPCC report. If you have the 1995 report you might want to scan it. Since this chapter was controversial for other reasons, for fun I included here a commentary describing that scientific fracas.
*Tuesday Mar. 2 Ecosystem responses to climate change impacts across natural systems
  1. A globally coherent fingerprint of climate impacts across natural systems Parmesan, C. and G. Yohe. Nature, 421, pg. 37 (2003)
  2. Supplementary color figures for Parmesan & Yohe 2003
  3. Supplementary discussion and figure captions for Parmesan & Yohe 2003
  4. Fingerprints of global warming on wild animals and plants Root, T.L. et al. Nature, 421, pg. 57 (2003)
  5. Supplementary tables for Root 2003
Scott Saleska Paul Koch, visiting faculty in isotope geochemistry & vertebrate paleontology from the University of Santa Cruz, will be participating in this discussion. Note special date.
Thursday Feb. 5 Is the Northerm Hemisphere Annular Mode (NAM) (aka the Arctic Oscillation (AO)) a phyically relevant phenomenon?
  1. Arctic Oscillation or North Atlantic Oscillation? Ambaum, M.H., B.J. Hoskins, and D.B. Stephenson. Journal of Climate, 14, pg. 3495 (2001)
  2. The Arctic Oscillation signature in the wintertime geopotential height and temperature fields Thompson, D.W. and J.M. Wallace. Geophys. Res. Lett., 25, pg. 1297-1300 (1998)
  3. The Pacific center of action of the Northern hemisphere annular mode: real or artifact? Wallace, J.M. and D.W. Thompson. Journal of Climate, 15, pg. 1987 (2002)
 Dylan Jones Can there be such as a thing as an oscillation without a defined period?
Thursday Jan. 22 Mass-independent isotope effects in atmospheric ozone
  1. Strange and unconventional isotope effects in ozone formation Gao and Marcus, Science, 293, pg. 259 (2001)
  2. Mass-independent isotope effects in planetary atmospheres and the early solar system. Thiemens, Science, 283, pg. 341 (1999)
  3. Does symmetry drive isotopic anomalies in ozone isotopomer formation? Technical comment in Science , 294, pg. 951a (2001)
  4. Ozone isotope enrichment: Isotopomer-specific rate coefficients Mauersberger et al., Science, 283, pg. 370 (1999)
Becky Alexander If you don't have time to read all these, read the Thiemens review paper and the technical comment for an overview and introduction. The Gao and Marcus paper proposes a theory for the observed mass-independent fractionation effect. Yi Qin Gao is here at Harvard and is going to try to attend the discussion to help explain. This discussion might still change date depending on Gao's schedule - stay tuned.
Thursday Jan. 8 Prehistoric development of agriculture as cause of significant greenhouse warming
  1. The Anthropogenic Greenhouse Era Began Thousands of Years Ago. Ruddiman, W. E., Climatic Change 61 (3): 261-293, December 2003
  2. Man has been changing climate for 8,000 years. Nature science update, 10 December 2003.
  3. Scientist Links Man to Climate Over the Ages. New York Times, Dec. 10 2003.
Paul Palmer Ruddiman made a big splash at AGU with this idea. It's a great story, but does the evidence bear it out? Was the reach of human activity enough to cause significant GHG enhancement even several thousand years ago? Can the Little Ice Age really be the result of forest regrowth in Europe after the Plague?
Thursday Dec. 18 Atmospheric hydrogen and effects of new fuel sources
  1. Potential environmental impact of a hydrogen economy on the stratosphere. Tromp TK, Shia RL, Allen M, Eiler JM, Yung YL SCIENCE 300 (5626): 1740-1742 Jun. 13, 2003
  2. Assessing the future hydrogen economy. Lovins, A. SCIENCE (Letters) Oct 10 2003
  3. Extreme deuterium enrichment in stratospheric hydrogen and the global atmospheric budget of H-2. Rahn T, Eiler JM, Boering KA, Wennberg PO, McCarthy MC, Tyler S, Schauffler S, Donnelly S, Atlas E NATURE 424 (6951): 918-921 AUG 21 2003
Fok-Yan Leung Is conversion to hydrogen-fuelled transportation really environmentally beneficial, or could there be detrimental side-effects? Tromp et. al discuss the changes in atmospheric chemistry that could result from projected leak rates of molecular hydrogen in a nationwide fuel system. John Eiler's paper covers a separate issue: new measurements of the isotopic composition of stratospheric H2 showing extreme enrichment due to kinetic fractionation during photochemistry.
Thursday Dec. 4 Oxygen isotopes in marine sulfate No paper this week - instead, AGU talks:
  1. Becky Alexander on "Modeling and measurements of oxygen isotope tracers of sulfate formation: Implications for the sulfur budget in the marine boundary layer"
  2. Sasha Turchyn on "Oxygen Isotopes in Marine Sulfate: Reassessing the sulfur cycle over the past 10 million years".
  3. Optional background material: Mass independent oxygen isotopic composition of atmospheric sulfate: origin and implications for the present and past atmosphere of earth and mars. Lee, Savarino and Thiemens, Geophys. Res. Lett., Vol 28, No. 9, pg. 1783-1783, 2001.
  4. Or, Becky's abstract
    5. .
Becky Alexander / Sasha Turchyn  
Thursday Nov. 20 Feedbacks in climate models
  1. Influence of cloud feedback on annual variation of global mean surface temperature,Tsushima, Y., and S. Manabe, Journal of Geophysical Research (Atmosphere) 106(D19), 22, 635-22,646, October 16, 2001.
 John Lin We're doing this paper in conjunction with the Houghton Lectures at MIT, given this year by Suki Manabe. This is the paper recommended by Manabe for his lecture on Tues. Nov. 18, "Reducing feedback uncertainty in climate models" (though it's of course fine to come to the discussion without having gone to the lecture). See http://web.mit.edu/eaps/events/index.shtml for the full schedule. There are 4 Houghton lectures in all, starting Nov. 12.
*Wednesday Oct. 29 1-2 PM Universal scaling laws in living systems

(a controversial subject in ecology)
  1. * The Fourth Dimension of Life: Fractal Geometry and Allometric Scaling of Organisms. West, Brown, & Enquist, Science, 1999, 284: 1677.
  2. All creatures great and small. Whitfield, Nature, 2001, 413: 342.(A news feature looking at the debate the scaling law work has generated)
  3. Global Allocation Rules for Patterns of Biomass Partitioning in Seed Plants.Enquist and Niklaus, Science, 2002.
  4. Sack et al. 2002.Technical comments about 3 in Science.
  5. Scaling metabolism from organisms to ecosystems. Enquist et al., Nature, 2003 423:639.
 Scott Saleska * note special day and time

Also: John Harte from UC Berkeley (author of “Consider a Spherical Cow”) will be a guest attendee.
Thursday Oct. 23 Sea ice and abrupt climate changes
  1. Sea ice as the glacial cycles' climate switch: Role of seasonal and orbital forcing Gildor H, Tziperman E PALEOCEANOGRAPHY 15 (6): 605-615 DEC 2000
  2. A sea ice climate switch mechanism for the 100-kyr glacial cycles Gildor H, Tziperman E J GEO RES 106 (C5): 9117-9133 MAY 2001
  3. Physical mechanisms behind biogeochemical glacial-interglacial CO2 variations Gildor H, Tziperman E GEOPHYSICAL RESEARCH LETTERS 28 (12): 2421-2424 JUN 15 2001
Liz Moyer Eli Tziperman is a new faculty member in EPS. He promises to attend this discussion (but in the interest of free speech will arrive for the 2nd half of the session only!).


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