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1. |
Do we know what difference a delay makes? |
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Eos, Transactions American Geophysical Union,
Volume 72,
Issue 53,
1991,
Page 593-593
James S. Risbey,
Mark David Handel,
Peter H. Stone,
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摘要:
In our original comment [Risbey et al.., 1991] we argued that the work of Schlesinger and Jiang [1991a]is too limited to determine whether or not (as they put it) “the penalty is small for a 10‐year delay in initiating the transition to a regime in which greenhouse‐gas emissions are reduced.” In their reply,Schlesinger and Jiang[1991b] (hereafter S&J) presented their reasons for concluding definitively that the penalty is small. However S&J's discussion of the evidence and literature on climate change and greenhouse warming contains significant omissions and mis‐statements.In dismissing our concern that their model was too simple to evaluate the possibility of abrupt climate change, S&J rely on results from coupled ocean‐atmosphere general circulation models (GCMs), in particular the work ofCubasch et al.. [1991]. Here S&J make two claims, one of which is incorrect and the other questionable. First, they claim that “the coupled atmosphere‐ocean model of Cubasch et al. [1991] does allow the nonlinearities thatRisbey et al.. [1991] criticize our simple model for not including.” In fact we explicitly mentioned changes in polar ice caps [Oerlemans and van der Veen, 1984] and release of methane from clathrates [MacDonald, 1990;Bell, 1982], neither of which are included in the model ofCubasch et al.. [1991]. Indeed, none of the published simulations of global warming using coupled ocean‐atmosphere GCMs include these effects. Nor do these models yet include in their enhanced greenhouse simulations many of the possible feedbacks involving the carbon cycle and biosphere [Lashof, 1989;Bacastow and Maier‐Reimer, 1990;Sellers, 1987] that could significantly alter greenhouse gas concentrations and surface properties. The published simulations with these models do allow for some changes in deep ocean circulation and cloud behavior, but there is controversy over whether they correctly represent these processes [Marotzke, 1991;Mitchell, 1989;Cess, 1990]. In addition the coupled models must be arbitrarily tuned (requiring substantial artificial fluxes of heat and moisture) to get the current climate right [Manabe et al.., 1991;Cubasch et al.., 1991]. Their greenhouse change simulations are at least partly constrained by t
ISSN:0002-8606
DOI:10.1029/90EO00413
年代:1991
数据来源: WILEY
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2. |
International geodesy discussed in Vienna |
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Eos, Transactions American Geophysical Union,
Volume 72,
Issue 53,
1991,
Page 594-595
Richard H. Rapp,
Bob Schutz,
Jean Dickey,
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摘要:
The International Association of Geodesy (IAG) met for 2 weeks in August 1991 during the 20th General Assembly of the IUGG in Vienna. Numerous plans were made for future scientific projects and meetings and a large number of scientific and administrative activities were completed.IAG is an organization whose objectives are to promote the study of scientific problems of geodesy;; to promote and coordinate international cooperation in geodesy;; and to provide, on an international basis, an opportunity for the discussion and publication of geodetic research. To implement these objectives, the IAG is organized into five sections and several groups that fall outside the section definition. The five sections are Positioning (I), Advanced Space Technology (II), Determination of the Gravity Field (III), General Theory and Methodology (IV), and Geodynamics (V). Each section has a structure that is organized through the president of the section.
ISSN:0002-8606
DOI:10.1029/90EO00411
年代:1991
数据来源: WILEY
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3. |
Biogeochemical processes in model estuaries |
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Eos, Transactions American Geophysical Union,
Volume 72,
Issue 53,
1991,
Page 595-598
Thomas M. Church,
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PDF (203KB)
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摘要:
Sixty researchers met to evaluate the effects of global change on estuaries and to improve estuarine modeling at the Second International Symposium on the Biogeochemistry of Model Estuaries, held April 15–19, 1991, at Jekyll Island, Ga. The importance of successful sampling in evaluating chemical fluxes and establishing records of estuarine change was articulated, as was the need for tracer tools for improved modeling. The symposium was sponsored by the National Science Foundation, National Oceanic and Atmospheric Administration, and the Department of Energy.Participants discussed particles and sedimentology, trace elements and metals, organic chemistry, and nutrient cycling of estuarine processes. Four days of presentations were followed by a half‐day of discussion on advances in these topics and the overall goal of assessing estuarine processes in global change. What follows is a synopsis of this discuss
ISSN:0002-8606
DOI:10.1029/90EO00410
年代:1991
数据来源: WILEY
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