Climate Research Network
Collaborative Research Agreement at the University of Victoria
on Behalf of the Canadian Institute for Climate Studies and Environment Canada
March 31, 2002
This progress report is available on the world wide web at:
1: Principal Investigator
Ed Carmack, Greg Flato, Lawrence Mysak
School of Earth & Ocean Sciences, University of Victoria
PO Box 3055, Victoria, BC, V8W 3P6
4: Research Progress
This progress report will briefly discuss research conducted during the third year of financial support from the MSC/CICS Arctic Node of the Canadian Climate Research Network. The McGill component of this project received a transfer of $40,000 in May 2001. This represents the last transfer as the McGill sea ice modelling effort, lead by Lawrence Mysak, will be funded off the NSERC/CFCAS CLIVAR collaborative grant effective 2002. Dr. Mysak will submit a final progress report separately.
This report will discuss only that research which has been completed since October 2001. The research discussed below is funded either in whole or in part off the CICS Arctic Grant. At the end of this brief report, a list of papers is provided which have been funded in whole or in part by the CICS Arctic grant to date.
4.1 Research funded from CICS Arctic Grant
20th century change in the Sea of Okhotsk and it implications for the North Pacific.
Katy Hill recently defended her MSc thesis and a paper arising from her work has been submitted to Atmosphere-Ocean. Russian data from 5 cruises during the period 1949 to 1952 were compared with observations taken during WOCE P1W in 1993 to examine changes which may have occurred in the Sea of Okhotsk during the latter half of the last century. A basinwide warming and freshening of the Sea of Okhotsk was found in the archived data. Since the Sea of Okhotsk is thought to be the major source region for North Pacific Intermediate water (NPIW), calculations were conducted to see whether or not this change in Sea of Okhotsk water properties is consistent with evidence of large-scale freshening of intermediate waters in the North Pacific. From several Okhotsk-to-Pacific salt flux calculations, we concluded that the Sea of Okhotsk was capable of causing the freshening noted in the NPIW over the past half century under certain assumed outflow conditions.
Internal tide driven mixing in a model of the oceanic general circulation
Dr. Harper Simmons was largely funded by an NSF International Research Fellowship, a grant from the International Arctic Research Center in Fairbanks, Alaska, as well as the CICS Arctic grant. Dr. Simons worked on developing new parametrisations for ocean mixing and geothermal heating. He recently relocated to Fairbanks Alaska to take up a permanent Research Scientist position at IARC .
Dr. Simmons recently wrote a paper which is to be submitted to Nature shortly concerning the large-scale ocean effects of using a new parametrisation of internal tide driven ocean mixing. Not only is the new parametrisation appealing from a physical standpoint, but it also significantly improves the climatology of an ocean general circulation model. In addition, Dr. Simmons is writing up some work examining the importance of geothermal heating on the large scale ocean circulation.
Freshwater transport through the southwest Canadian Archipelago
The input of fresh water from the Arctic into the North Atlantic via the transport of sea ice and low salinity waters is an important component of the global climate system through its effects on deepwater formation. Part of this fresh water is transported through the Canadian Arctic Archipelago (CAA) by shallow, coastal-trapped buoyancy-driven boundary currents (BBCs). CTD data collected between Dolphin and Union Strait and Queen Maud Gulf in the summers of 1995, 1999, and 2000 were examined to show the structure and behaviour of BBCs. These hydrographic data were also supplemented with traditional knowledge. The presence of driftwood originating from the Mackenzie River, predominantly on the south side of channels, supports an eastward transport through the region. The presence of BBCs on both sides of the channels appears to be a frequent occurrence, but with the fresher water being more often present on the south shore. Some data from the summer 2000 showed a different feature with much fresher water on the north side. A subsequent strong wind event created a complete reversal of this situation, setting up a strong cross-channel horizontal salinity gradient and an amplified BBC on the south shore. This observation was supported by dynamical considerations in that the internal Froude number for the BBCs is generally very small, allowing dissipation of the BBCs. As such, BBCs in the CCA, away from the mouth of major rivers or along ice edges, are likely transient features that respond strongly to local wind stress changes. Still, the net transport of these BBCs is eastward associated with the mean eastward wind stress. Freshwater transport estimates of 30 to 585m3/s (0.95 to 18.5 km3/yr) were found for a variety of BBCs.
This work, which arose from Gilles Arfeuille's successfully-defended his MSc thesis, has recently been submitted for publication to Atmosphere-Ocean.
Julie Bacle is a second-year PhD student working under the supervision of A. Weaver and E. Carmack. In the past year she has focused her thesis topic on the physical and geochemical oceanography of Baffin Bay, has written a literature review pertinent to her research direction, has selected her reviewing committee, and has submitted two papers for publication (listed below) which she will be presenting at the next CMOS meeting in May.
Bâcle, J., E.C. Carmack and R.G. Ingram, 2002. Water column structure and circulation in the North Water during spring transition: April-July 1998. Deep-Sea Res. II, in press.
Bâcle, J. and E.C. Carmack, 2002. A thermohaline front formed at the confluence of Arctic- and Atlantic-derived waters in northern Baffin Bay: implications for mixing and the production of Arctic outflow waters. Journal of Physical Oceanography, submitted.Jacqueline Dumas
During the past year CRN funds have been used to support Jacqueline Dumas in her pursuit of a Masters degree in Earth and Ocean Science. Her research project (supervised by G. Flato) is based on Activity 4.4 in the research agreement, namely the analysis of statistical relationships between Arctic climate indices. In particular, Ms. Dumas is making use of the Arctic drifting station data set (measurements made from the 1950s to early 1990s at drifting ice camps operated by the former Soviet Union). She is conducting an extensive analysis of the relationship between in-situ meteorological observations and large-scale circulation indices (such as the 'Arctic Oscillation', the 'Pacific North America' pattern, etc.) to explore the consequences of variations in large-scale circulation on local conditions relevant to sea-ice evolution. She will ultimately be running a one-dimensional sea-ice model to explore the connection between large-scale atmospheric variability and multi-year sea-ice mass balance. Ms. Dumas has presented initial results to her thesis committee, and is preparing a presentation for the annual CRYSYS workshop in Victoria 24-26 March, 2002, and the CMOS Congress in May, 2002. The expectation is that Ms. Dumas will complete her degree by September, 2002, with a peer-reviewed publication to follow.
The UVic Earth System Climate Model
The sea ice model developed as part of CICS Arctic funding (Bitz et al. 2001) and implemented into the CCCma CGCM3 (Saenko et al., 2002) was built within the context of the newly developed UVic earth system climate model. A lengthy paper using this model recently appeared in Atmosphere-Ocean (Weaver et al., 2002).
The UVic Earth System Climate Model consists of a three-dimensional ocean general circulation model coupled to a thermodynamic/dynamic sea ice model, an energy-moisture balance atmospheric model with dynamical feedbacks, and a thermomechanical land ice model. In order to keep the model computationally efficient a reduced complexity atmosphere model is used. Atmospheric heat and freshwater transports are parametrised through Fickian diffusion, and precipitation is assumed to occur when the relative humidity reaches greater than 85%. Moisture transport can also be accomplished through advection if desired. Precipitation over land is assumed to instantaneously return to the ocean via one of 33 observed river drainage basins. Ice and snow albedo feedbacks are included in the coupled model by locally increasing the prescribed latitudinal profile of the planetary albedo. The atmospheric model includes a parametrisation of water vapour/planetary long wave feedbacks, although the radiative forcing associated with changes in atmospheric CO2 is prescribed as a modification of the planetary long wave radiative flux. A specified lapse rate is used to reduce the surface temperature over land where there is topography. The model uses prescribed present day winds in its climatology although a dynamical wind feedback is included which exploits a latitudinally-varying empirical relationship between atmospheric surface temperature and density. The ocean component of the coupled model is based on the GFDL Modular Ocean Model 2.2, with a global resolution of 3.6° (zonal) by 1.8° (meridional) and 19 vertical levels, that includes an option for a brine-rejection parametrisation.
The sea ice component incorporates an elastic-viscous-plastic rheology to represent sea ice dynamics and various options for the representation of sea ice thermodynamics and thickness distribution. The systematic comparison of the coupled model with observations revealed good agreement, especially when moisture transport is accomplished through advection. Global warming simulations conducted using the model to explore the role of moisture advection revealed a climate sensitivity of 3.0°C for a doubling of CO2, in line with other more comprehensive coupled models. Moisture advection, together with the wind feedback lead to a transient simulation in which the meridional overturning in the North Atlantic initially weakened, but eventually re-established to its initial strength once the radiative forcing was held fixed, as found in many coupled atmosphere GCMs. This is in contrast to experiments in which moisture transport was accomplished through diffusion whereby the overturning re-established to a strength that is greater than its initial condition.
When applied to the climate of the Last Glacial Maximum, the model obtained tropical cooling (30° N30° S), relative to the present, of about 2.1 °C over the ocean and 3.6° C over the land. These are generally cooler than CLIMAP estimates, but not as cool as some other reconstructions. This moderate cooling is consistent with alkenone reconstructions and a low to mid climate sensitivity to perturbations in radiative forcing. An amplification of the cooling occured in the North Atlantic due to the weakening of North Atlantic Deep Water formation. Concurrent with this weakening was a shallowing and a more northward penetration of Antarctic Bottom Water.
Climate models are usually evaluated by spinning them up under perpetual present-day forcing and comparing the model results with present-day observations. Implicit in this approach is the assumption that the present day observations are in equilibrium with the present day radiative forcing. The comparison of a long transient integration (starting at 6 KBP), forced by changing radiative forcing (solar, CO2, orbital), with an equilibrium integration revealed substantial differences. Relative to the climatology from the present-day equilibrium integration, the global mean surface air and sea surface temperatures (SSTs) were 0.74 °C and 0.55°C colder, respectively, deep ocean temperatures were substantially cooler, and southern hemisphere sea ice cover was 22% larger, although the North Atlantic conveyor remained remarkably stable in all cases. The differences are due to the long timescale memory of the deep ocean to climatic conditions which prevailed throughout the late Holocene. It was also demonstrated that a global warming simulation that starts from an equilibrium present-day climate (cold start) underestimates the global temperature increase at 2100 by 13% when compared to a transient simulation, under historical solar, CO2 and orbital forcing, that is also extended out to 2100. This is larger (13% compared to 9.8%) than the difference from an analogous transient experiment which does not include historical changes in solar forcing. These results suggest that those groups that do not account for solar forcing changes over the 20th century may slightly underestimate (~3% in our model) the projected warming by the year 2100.
Distinguishing the influences of heat, freshwater and momentum fluxes on ocean circulation and climate
The separate and combined effects of windstress and freshwater forcing on the ocean circulation and on ocean transports of heat and freshwater were analyzed using the UVic coupled model. Suppressing the freshwater flux weakens the north Atlantic meridional overturning by 15% of its control value. With thermal forcing (no freshwater or momentum fluxes), it falls by only 20%. Thermal forcing is therefore dominant, in contradiction to the suggestion that freshwater forcing (net evaporation in the Atlantic) is the major driving force of this circulation. In the north Pacific, the meridional overturning intensifies, resulting in the appearance of a deep western boundary current there. Supressing the momentum flux (windstress) eliminates the subtropical barotropic gyres and reduces the flow through the Drake Passage by 65%, but does not lead to a substantial weakening of the deep outflow from the Atlantic at 30 S. However, with thermal forcing only, the outflow is reduced by 75%, suggesting that in this model the outflow is controlled by thermohaline rather than windstress forcing. Ocean meridional heat transport is somewhat sensitive to the removal of freshwater and momentum forcing, but freshwater transport is not. We showed that gyre transport cannot be attributed uniquely to windstress forcing, and argue that the question remains open as to whether the thermohaline "conveyor" transports freshwater into or out of the Atlantic.
Using of CFC-11 to evaluate the role of wind-driven sea ice motion on ocean ventilation.
Simulations with the UVic coupled model were used to investigate the role of wind-driven sea ice motion on ocean ventilation. Two model experiments were analyzed in detail: one including and the other excluding wind driven sea ice transport. Model simulated concentrations of chlorofluorocarbons (CFCs) were compared with observations from the Weddell Sea, the southeastern Pacific and the North Atlantic. We showed that the buoyancy fluxes associated with wind driven sea ice motion control the sites and rates of deep and intermediate water formation in the Southern Ocean. Divergence of sea ice along the Antarctic perimeter facilitates bottom water formation in the Weddell and Ross Seas. Neglecting wind driven sea ice transport results in unrealistic bottom water formation in the Drake Passage and too strong convection along the Southern Ocean sea ice margin, whereas convection in the Weddell and Ross Seas is suppressed. The freshwater fluxes implicitly associated with sea ice export also determine the intensity of the gyre circulation and the rate of downwelling in the Weddell Sea. In the North Atlantic, wind-driven sea ice export from the Arctic weakens and shallows the meridional overturning cell. This results in a decreased surface flux of CFCs around 65°N by about a factor of two. Convection in the North Atlantic was found to be less affected by the wind-induced sea ice transport compared to that in the Southern Ocean.
North Atlantic Response to the Above-Normal Export of Sea Ice from the Arctic
The response of the thermohaline circulation (THC), as well as the freshwater and heat budgets of the northern North Atlantic, to above-normal sea ice export from the Arctic were examined using a coupled model. Two cases were considered: a pulse-like and a persistent above-normal export of sea ice from the Arctic. In the pulse-like case, the export of ice was doubled and sustained at that level for a specified period of time, ranging from one to five years. We showed that, depending on the cumulative ice flux, the strength of the THC and the heat transport from the subtropics to the subpolar North Atlantic decreased by 5-20%. It took 15-20 years for the extra sea ice to convert into the freshwater anomaly and propagate towards and then within the North Atlantic water column of deep water formation, from the surface to the depths below 1000 m. About the same time was needed for the THC to return to its normal (control) state.
In the case of a persistent above-normal export of sea ice from the Arctic, the THC did not collapse, at least within the range of the ice export increase (1.5 to 3 times) we used. Rather, after about 15-20 years the THC showed a tendency for returning back to its normal (control) state. Two factors are involved in this process. First, the internal (to the coupled system) redistribution of freshwater between the Arctic and North Atlantic, associated with the enhanced export of sea ice, makes the North Atlantic fresher and Arctic Ocean saltier. This, if persistent, decreases the amount of freshwater leaving the Arctic towards the North Atlantic in a liquid form. Second, because the THC does not collapse, the freshwater anomaly propagates downward in the North Atlantic, removing the excess of buoyancy from the surface.
It was suggested that the decadal time scale of 15-20 years for North Atlantic THC variability is linked to the variability of sea ice export on different time scales. The variability of sea ice export produces freshwater anomalies within the Arctic Ocean and North Atlantic of opposite sign. It then takes about the same time (15-20 years) for the freshwater anomalies to both propagate horizontally from the Arctic Ocean interior to the North Atlantic region of deep water formation and downward within the North Atlantic water column. Other graduate student projects
Hannah Hickey holds an NSERC PGSA award and started her MSc (September 2001) under the supervision of A. Weaver. She is examining the link between high latitude and tropical low frequency climate variability via oceanic subduction. Linda Waterman continues to work towards the understanding of sub grid scale mixing processes on high latitude ocean circulation and its sea ice cover.
5. Publications for Weaver since the beginning of CICS Arctic funding in 1999.
(Those numbers in bold indicated publications supported by the CICS Arctic/Variability Projects)
1. Weaver, A.J., C.M. Bitz, A.F. Fanning and M.M. Holland, 1999: Thermohaline circulation: High latitude phenomena and the difference between the Pacific and Atlantic. Annual Review of Earth and Planetary Sciences, 27, 231-285.
2. National Research Council, 1999: Global Ocean Science: Toward an Integrated Approach. National Academy Press, Washington, D.C., 165pp.
3. Weaver, A.J., 1999: Extratropical subduction and decadal modulation of El Niño. Geophysical Research Letters, 26, 743-746.
4. Huck, T., A. Colin de Verdière and A.J. Weaver, 1999: Interdecadal variability of the thermohaline circulation in box-ocean models forced by fixed surface fluxes. Journal of Physical Oceanography, 29, 865-892.
5. Huck, T., A.J. Weaver and A. Colin de Verdière, 1999: On the influence of the parameterisation of lateral boundary layers on the thermohaline circulation in coarse-resolution ocean models. Journal of Marine Research, 57, 387-426.
6. Duffy, P.B., M. Eby and A.J. Weaver, 1999: Effects of sinking of salt rejected during formation of sea ice on results of a global ocean-atmosphere-sea ice climate model. Geophysical Research Letters, 26, 1739-1742.
7. Poussart, P.F., A.J. Weaver and C.R. Barnes, 1999: Late Ordovician glaciation under high atmospheric CO2: A coupled model analysis. Paleoceanography, 14, 542-558.
8. Weaver, A.J., 1999: Millennial timescale variability in ocean/climate models. In: Mechanisms of Global Climate Change at Millennial Time Scales. Webb R.S., P.U. Clark, and L.D. Keigwin Eds., American Geophysical Union, Geophysical Monograph Vol. 112, Washington, D.C., pp. 285-300.
9. Wiebe, E.C. and A.J. Weaver, 1999: On the sensitivity of global warming experiments to the parametrisation of sub-grid scale ocean mixing. Climate Dynamics, 15, 875-893.
10. Weaver, A.J. and E.C. Wiebe, 1999: On the sensitivity of projected oceanic thermal expansion to the parameterisation of sub-grid scale ocean mixing. Geophysical Research Letters, 26, 3461-3464.
11. Holland, M.M., A.J. Brasket and A.J. Weaver, 2000: The impact of rising atmospheric CO2 on low frequency North Atlantic climate variability. Geophysical Research Letters, 27, 1519-1522.
12. Weaver, A.J., P.B. Duffy, M. Eby and E.C. Wiebe, 2000: Evaluation of ocean and climate models using present-day observations and forcing. Atmosphere-Ocean, 38, 271-301.
13. Stone, D.A., A.J. Weaver and F.W. Zwiers, 2000: Trends in Canadian precipitation intensity. Atmosphere-Ocean, 38, 321-347.
14. Flato, G.M., G.J. Boer, W.G. Lee, N.A. McFarlane, D. Ramsden, M.C. Reader and A.J. Weaver, 2000: The Canadian Centre for Climate Modelling and Analysis global coupled model and its climate. Climate Dynamics, 16, 451-467.
15. Rutter, N.W., A.J. Weaver, D. Rokosh, A.F. Fanning and D.G. Wright, 2000: Data-model comparison of the Younger Dryas event. Canadian Journal of Earth Sciences, 37, 811-830.
16. Weaver, A.J., and F.W. Zwiers, 2000: Uncertainty in climate change Nature, 407, 571-572.
17. Zwiers, F.W., and A. J. Weaver, 2000: The causes of 20th century warming, Science, 290, 2081-2082.
18. Weaver, A.J. and H. Raptis, 2001: Gender differences in introductory atmospheric and oceanic science exams: Multiple choice versus constructed response questions. Journal of Science Education and Technology, 10, 115-126.
19. Duffy, P.B., M. Eby and A.J. Weaver, 2001: Climate model simulations of effects of increased atmospheric CO2 and loss of sea ice on ocean salinity and tracer uptake. Journal of Climate, 14, 520-532.
20. Bitz, C.M., M.M. Holland, A.J. Weaver and M. Eby, 2001: Simulating the ice-thickness distribution in a coupled climate model. Journal of Geophysical Research, 106, 2441-2463.
21. Schmittner, A. and A.J. Weaver, 2001: Dependence of multiple climate states on ocean mixing parameters. Geophysical Research Letters, 28, 1027-1030.
22. Holland, M.M., C.M. Bitz, M. Eby and A.J. Weaver, 2001: The role of ice ocean interactions in the variability of the North Atlantic thermohaline circulation. Journal of Climate, 14, 656-675.
23. Hillaire-Marcel, C., A. de Vernal, G. Bilodeau and A.J. Weaver, 2001: Absence of deep-water formation in the Labrador Sea during the last interglacial period. Nature, 410, 1073-1077.
24. Yoshimori, M., A.J. Weaver, S.J. Marshall and G.K.C. Clarke, 2001: Glacial termination: Sensitivity to orbital and CO2 forcing in a coupled climate system model. Climate Dynamics, 17, 571-588.
25. McAvaney, B.J., C. Covey, S. Joussaume, V. Kattsov, A. Kitoh, W. Ogana, A.J. Pitman, A.J. Weaver, R.A. Wood, and Z.-C. Zhao, 2001: Model evaluation. In: Climate Change 2001: The Scientific Basis. Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change. Houghton, J.T., Y. Ding, D.J. Griggs, M. Noguer, P.J. van der Linden, X. Dai, K. Maskell, and C.A. Johnson, Eds., Cambridge University Press, Cambridge, England, pp. 471-523.
26. Stone, D.A., A.J. Weaver and R.J. Stouffer, 2001: Projection of climate change onto modes of atmospheric variability. Journal of Climate, 14, 3551-3565.
27. Holland, M.M., C.M. Bitz and A.J. Weaver, 2001: The influence of sea ice physics on simulations of climate change. Journal of Geophysical Research, 106, 19,639-19,655.
28. Saenko, O., and A. J. Weaver, 2001: Importance of wind-driven sea ice motion for the formation of Antarctic Intermediate Water in a global climate model. Geophysical Research Letters, 28, 4147-4150.
29. McBean, G., A Weaver and N. Roulet, 2001: The Science of Climate Change: What do we know? ISUMA: Canadian Journal of Policy Research, 2(4), 16-25.
30. Weaver, A.J., M. Eby, E. C. Wiebe, C. M. Bitz, P. B. Duffy, T. L. Ewen, A. F. Fanning, M. M. Holland, A. MacFadyen, H. D. Matthews, K. J. Meissner, O. Saenko, A. Schmittner, H. Wang and M. Yoshimori, 2001: The UVic Earth System Climate Model: Model description, climatology and application to past, present and future climates. Atmosphere-Ocean, 39, 361-428.
31. Yoshimori, M., M.C. Reader, A.J. Weaver and N.A. MacFarlane, 2002: On the causes of glacial inception at 116KaBP. Climate Dynamics, 18, 383-402.
32. Clark, P.U., N.G. Pisias, T.F. Stocker, and A.J. Weaver, 2002: The role of the thermohaline circulation in abrupt climate change. Nature, 415, 863-869.
33. Schmittner, A., M. Yoshimori and A.J. Weaver, 2002: Instability of glacial climate in a model of the ocean-atmosphere-cryosphere system. Science, 295, 1489-1493.
34. Claussen, M., L. A. Mysak, A. J. Weaver, M. Crucifix, T. Fichefet, M.-F. Loutre, S. L. Weber, J. Alcamo, V.A. Alexeev, A. Berger, R. Calov, A. Ganopolski, H. Goosse, G. Lohman, F. Lunkeit, I.I. Mohkov, V. Petoukhov, P. Stone and Z. Wang, 2001: Earth system models of intermediate complexity: Closing the gap in the spectrum of climate system models. Climate Dynamics, 18, 579-586.
35. Saenko, O., G. M. Flato and A. J. Weaver, 2002: Improved representation of sea-ice processes in climate models. Atmosphere-Ocean, 40, 21-43.
- Refereed Publications (in press)
36. Schmittner, A., K.J. Meissner, M. Eby and A. J. Weaver, 2001: Forcing of the deep ocean circulation in simulations of the Last Glacial Maximum. Paleoceanography, in press.
37. Meissner, K.J., A. Schmittner, E.C. Wiebe and A.J. Weaver, 2002: Simulations of Heinrich Events in a coupled ocean-atmosphere-sea ice model. Geophysical Research Letters, in press.
38. McLaughlin, F.A., E. Carmack, R. Macdonald, A.J. Weaver and J. Smith, 2002: The Canada Basin 1989-1995: Upstream events and far-field effects of the Barents Sea branch. Journal of Geophysical Research., in press.
39. de Vernal, A., C. Hillaire-Marcel, W.R. Peltier and A.J. Weaver, 2002: The structure of the upper water column in the northwest North Atlantic: Modern vs. last glacial maximum conditions. Paleoceanography, in press.
40. Stone, D.A., and A. J. Weaver, 2002: Daily maximum and minimum temperature trends in a climate model. Geophysical Research Letters, in press.
- Refereed Publications (submitted)
41. Saenko, O.A., E.C. Wiebe, and A.J. Weaver, 2002: North Atlantic response to the above-normal export of sea-ice from the Arctic. J. Geophys. Res., Submitted.
42. Arfeuille, G., A.J. Weaver, E.C. Carmack, F.A. McLaughlin, and G.M. Flato, 2002: Freshwater transport through the southwest Canadian Arctic Archipelago due to buoyancy and wind forcing: Dolphin and Union Strait to Queen Maud Gulf. Atmosphere-Ocean, submitted.
43. Saenko, O.A., A. Schmittner, and A.J. Weaver, 2002: On the use of CFC-11 to evaluate the role of wind-driven sea ice motion on ocean ventilation. Journal of Physical Oceanography, submitted.
44. Yoshimori, M. and A.J. Weaver, 2002: Response of the thermohaline circulation to orbital forcing. Journal of Climate, submitted.
45. Weaver, A.J., 2002: The science of climate change. In: Climate Change in Canada. Coward, H.G., and A.J. Weaver, Eds. Wilfred Laurier Press, Waterloo, Ontario, Canada, submitted.
46. Saenko, O.A., J.M. Gregory, A.J. Weaver and M. Eby, 2002: Distinguishing the influences of heat, freshwater and momentum fluxes on ocean circulation and climate. Journal of Climate, submitted.
47. Stone, D.A. and A.J. Weaver, 2002: Diurnal temperature range trends in 20th and 21st century simulations of the CCCma coupled model. Climate Dynamics, submitted.
48. Meissner, K.J., A. Schmittner and A.J. Weaver, 2002: The ventilation of the North Atlantic Ocean during the Last Glacial Maximum A comparison between simulated and observed radiocarbon ages. Paleoceanography, submitted.
49. Hill, K.L., A.J. Weaver, H.J. Freeland and A. Bychkov, 2002: Evidence for change in the Sea of Okhotsk: Implications for the North Pacific. Atmosphere-Ocean, submitted.