Paleoclimatic reconstructions in western Canada from boreholetemperature logs: surface air temperature forcing and groundwater flow

Majorowicz, Jacek; Grasby, Stephen E.; Ferguson, Grant; Šаfanda, Jan; Skinner, W.

doi:10.5194/cp-2-1-2006

Cited by 29 publications

(28 citation statements)

References 29 publications

(36 reference statements)

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“…The result from Outokumpu may be also irrelevant as it was obtained for shallow boreholes (790-1100 m) and under 2-D heat transfer conditions. Our analysis shows that insufficient depths may lead to underestimation of paleotemperature changes (Golovanova et al, 2002; this effect was also mentioned in Majorowicz et al, 2002Majorowicz et al, , 2006. However, it must not be ruled out that comparatively low PHW amplitudes in these sites reflect the spatial temperature variations at the base of the Scandinavian Ice Sheet.…”

Section: Deviation From the Regular Patternmentioning

confidence: 85%

Spatial distribution of Pleistocene/Holocene warming amplitudes in Northern Eurasia inferred from geothermal data

et al. 2007

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Abstract. We analyze 48 geothermal estimates of Pleistocene/Holocene warming amplitudes from various locations in Greenland, Europe, Arctic regions of Western Siberia, and Yakutia. The spatial distribution of these estimates exhibits two remarkable features. (i) In Europe and part of Asia the amplitude of warming increases toward the northwest and displays clear asymmetry with respect to the North Pole. The region of maximal warming is close to the North Atlantic. A simple parametric dependence of the warming amplitudes on the distance to the warming center explains 91% of the amplitude variation. The Pleistocene/Holocene warming center is located northeast of Iceland. We claim that the Holocene warming is primarily related to the formation (or resumption) of the modern system of currents in the North Atlantic. (ii) In Arctic Asia, north of the 68-th parallel, the amplitude of temperature change sharply decreases from South to North, reaching zero and even negative values. These small or negative amplitudes could be attributed partially to a joint influence of Late Pleistocene ice sheets. Using a simple model of the temperature regime underneath the ice sheet we show that, depending on the relationship between the heat flow and the vertical ice advection velocity, the base of the glacier can either warm up or cool down. Nevertheless, we speculate that the more likely explanation of these observations are warmwater lakes thought of have formed in the Late Pleistocene by the damming of the Ob, Yenisei and Lena Rivers.

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Section: Deviation From the Regular Patternmentioning

confidence: 85%

Spatial distribution of Pleistocene/Holocene warming amplitudes in Northern Eurasia inferred from geothermal data

et al. 2007

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“…Thus, a key question is whether long-term trends in air and ground temperature are similar. Although there are clear exceptions (Gosnold et al 1997), the majority of evidence indicates that this similarity is generally strong: As a large-scale geographic average, measured ground temperatures match those predicted directly from air temperature changes (Harris and Chapman 2001), and air versus ground temperature trends are similar at some specific sites (Baker and Ruschy 1993, Majorowicz and Safanda 2005, Majorowicz et al 2006.…”

Section: Limits On Borehole-based Reconstructionsmentioning

confidence: 98%

“…Borehole-based temperature reconstructions averaged for broad regions (including eastern North America, western North America, Europe, Australia, and South Africa) show warming from the 19th century to the present and persistently cool conditions for the preceding few centuries (Gosnold et al 1997and references therein, Huang et al 2000, Harris and Chapman 2001, Majorowicz et al 2006. Temperature changes for earlier times are not resolvable.…”

Section: Boreholes In Rock and Permafrostmentioning

confidence: 99%

“…Analyses of a large number of continental boreholes have yielded temperature reconstructions for the last 500 years (Lachenbruch and Marshall 1986, Harris and Chapman 2001, Majorowicz et al 2006. These reconstructions have particular value because they do not have to be calibrated against the instrumental record and because temperature itself is being measured, not a proxy for temperature.…”

Section: Boreholes In Rock and Permafrostmentioning

confidence: 99%

“…The vertical distribution of temperature below the surface thus contains information about past temperatures at the surface (Lachenbruch andMarshall 1986, Paterson 1994). Temperature-depth profiles of this sort are measured in boreholes, and analyses of these data can be used to generate reconstructions of near-surface air temperature (Lachenbruch and Marshall 1986, Harris and Chapman 2001, Majorowicz et al 2006, provided that the ground surface temperature and the climatic temperature at the borehole site are closely connected.…”

Section: Boreholesmentioning

confidence: 99%

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Surface Temperature Reconstructions for the Last 2,000 Years

North¹

2006

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Our understanding of climate and how it has varied over time is advancing rapidly as new data are acquired and new investigative instruments and methods are employed. Thus in 2005, I suggested to the U.S. Congress that the National Research Council (NRC) could help answer questions about the data and methods that have been used in constructing records of Earth's surface temperatures from times when there were no scientific instruments, using proxy indicators. How has temperature varied over the last 2,000 years? How certain is the answer to this question? Subsequently, this study was requested by Representative Sherwood Boehlert, chairman of the Committee on Science, U.S. House of Representatives. Chairman Boehlert asked for a clear and concise report in a relatively short period of time, and the NRC agreed to undertake the study quickly. An ad hoc committee was formed, with the group carefully composed to include the breadth and depth of expertise and perspectives needed to analyze all aspects of how surface temperatures are estimated and interpreted and to comment generally on climate science. The NRC asked the committee to summarize current scientific information on the temperature record for the past two millennia, describe the main areas of uncertainty and how significant they are, describe the principal methodologies used and any problems with these approaches, and explain how central is the debate over the paleoclimate temperature record to the state of scientific knowledge on global climate change.The committee has prepared a report that, in my view, provides policy makers and the scientific community with a critical view of surface temperature reconstructions and how they are evolving over time, as well as a good sense of how important our understanding of the paleoclimate temperature record is within the overall state of scientific knowledge on global climate change. The report does not make policy recommendations.I thank the members of the committee, who worked intensely to produce this careful report in a short period of time and contributed much personal time, insight, and energy. ForewordCopyright © National Academy of Sciences. All rights reserved.Surface Temperature Reconstructions for the Last 2,000 Years http://www.nap.edu/catalog/11676.htmlThe NRC staff and all those who contributed papers, data, graphics, and other information, as well as the independent experts who participated in the rigorous review process, were essential participants. Surface Temperature Reconstructions for the Last 2,000 Years http://www.nap.edu/catalog/11676.html ix This committee was asked to describe and assess the state of scientific efforts to reconstruct surface temperature records for the Earth over approximately the last 2,000 years. (The full Statement of Task appears in Appendix A.) Normally, a technical issue such as surface temperature reconstructions might not generate widespread attention, but this case brings interesting lessons about how science works and how science, especially climate science, is commun...

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Analytical solution and computer program (FAST) to estimate fluid fluxes from subsurface temperature profiles

Kurylyk

Irvine

2016

Water Resources Research

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This study details the derivation and application of a new analytical solution to the onedimensional, transient conduction-advection equation that is applied to trace vertical subsurface fluid fluxes. The solution employs a flexible initial condition that allows for nonlinear temperature-depth profiles, providing a key improvement over most previous solutions. The boundary condition is composed of any number of superimposed step changes in surface temperature, and thus it accommodates intermittent warming and cooling periods due to long-term changes in climate or land cover. The solution is verified using an established numerical model of coupled groundwater flow and heat transport. A new computer program FAST (Flexible Analytical Solution using Temperature) is also presented to facilitate the inversion of this analytical solution to estimate vertical groundwater flow. The program requires surface temperature history (which can be estimated from historic climate data), subsurface thermal properties, a present-day temperature-depth profile, and reasonable initial conditions. FAST is written in the Python computing language and can be run using a free graphical user interface. Herein, we demonstrate the utility of the analytical solution and FAST using measured subsurface temperature and climate data from the Sendia Plain, Japan. Results from these illustrative examples highlight the influence of the chosen initial and boundary conditions on estimated vertical flow rates. Key Points:A solution is derived to estimate subsurface water flow from temperature The boundary and initial conditions are more flexible than in past solutions A new program FAST is presented to facilitate solution inversion Supporting Information:Supporting Information S1 Software S1 Software S2

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Paleoclimatic reconstructions in western Canada from boreholetemperature logs: surface air temperature forcing and groundwater flow

Cited by 29 publications

References 29 publications

Spatial distribution of Pleistocene/Holocene warming amplitudes in Northern Eurasia inferred from geothermal data

Spatial distribution of Pleistocene/Holocene warming amplitudes in Northern Eurasia inferred from geothermal data

Surface Temperature Reconstructions for the Last 2,000 Years

Analytical solution and computer program (FAST) to estimate fluid fluxes from subsurface temperature profiles

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