Ground temperature changes in eastern Canada: borehole temperature evidence compared with proxy data

Abstract. Long-term borehole temperature monitoring in mountain permafrost environments is challenging under the hostile conditions reigning in alpine environments. On the basis of data measured in the SLF borehole network we show three situations where ground temperature data should be interpreted with caution. (i) Thermistors have the tendency to drift, particularly if exposed to moisture or mechanical strain. This induces apparent warming or cooling, which can be difficult to differentiate from real ground temperature changes. Recalibration of thermistor chains is impossible if they cannot be extracted as a result of borehole deformation in creeping permafrost terrain. A solution using zero-curtain-based detection of drift and correction of data is presented. This method is however limited to the active layer, due to the lack of a reference temperature at greater depth. (ii) In contrast to drift-induced apparent warming, actual warming may be induced by natural processes or by the effects of construction activity. (iii) Control data from neighbouring boreholes are sometimes used to fill data gaps and discern drift – however these data may only underline the strong spatial variability of ground temperatures rather than provide measurement redundancy. A selection of recently observed problems regarding borehole monitoring in a hostile measurement environment are discussed, and advantages and possible drawbacks of various solutions including measurement redundancy or alternate instrumentation are presented.

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ANALYSIS OF ANNUAL VARIATIONS IN GROUND TEMPERATURE AT AN OTTAWA SITE

Canadian Journal of Earth Sciences ◽

10.1139/e64-008 ◽

1964 ◽

Vol 1 (2) ◽

pp. 146-157 ◽

Cited By ~ 2

Author(s):

L. W. Gold

Keyword(s):

Gradual Increase ◽

Ground Temperature ◽

Small Temperature ◽

Temperature Changes ◽

Annual Variations ◽

Periodic Fluctuations ◽

A Site

Observations over a 5-year period at a site at Ottawa showed that the ground temperature had significant Fourier components with period [Formula: see text]and 2 years. The average annual ground temperature and amplitudes of the Fourier components of period 1 year and [Formula: see text] year underwent non-periodic fluctuations of almost 1 C degree at a depth of 10 cm. The amplitude of this fluctuation decreased with depth, and its maximum occurred later in time. There was evidence of a gradual increase in average annual ground temperature amounting to about 0.2 C degree over the 5-year period at the 610-cm depth. The significance of such small temperature changes in areas where the ground temperature is close to 0 °C is pointed out.

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Impact of postglacial warming on borehole reconstructions of last millennium temperatures

Climate of the Past ◽

10.5194/cp-8-1059-2012 ◽

2012 ◽

Vol 8 (3) ◽

pp. 1059-1066 ◽

Cited By ~ 18

Author(s):

V. Rath ◽

J. F. González Rouco ◽

H. Goosse

Keyword(s):

Climate Models ◽

Ground Surface ◽

Geothermal Gradient ◽

Temperature Profiles ◽

Temperature Changes ◽

Open Questions ◽

Temperature Signal ◽

Borehole Temperatures ◽

Borehole Temperature ◽

The Impact

Abstract. The investigation of observed borehole temperatures has proved to be a valuable tool for the reconstruction of ground surface temperature histories. However, there are still many open questions concerning the significance and accuracy of the reconstructions from these data. In particular, the temperature signal of the warming after the Last Glacial Maximum is still present in borehole temperature profiles. It is shown here that this signal also influences the relatively shallow boreholes used in current paleoclimate inversions to estimate temperature changes in the last centuries by producing errors in the determination of the steady state geothermal gradient. However, the impact on estimates of past temperature changes is weaker. For deeper boreholes, the curvature of the long-term signal is significant. A correction based on simple assumptions about glacial–interglacial temperature changes shows promising results, improving the extraction of millennial scale signals. The same procedure may help when comparing observed borehole temperature profiles with the results from numerical climate models.

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Field measurement of ground temperatures in Bandung: devices and the results of measurement

E3S Web of Conferences ◽

10.1051/e3sconf/202020002009 ◽

2020 ◽

Vol 200 ◽

pp. 02009

Author(s):

Muhammad Nur Fajri Alfata ◽

Amalia Nurjannah

Keyword(s):

Temperature Sensor ◽

Field Measurement ◽

Ground Temperature ◽

Passive Cooling ◽

Temperature Profiles ◽

Temperature Changes ◽

Ground Temperatures ◽

Different Depths ◽

Measurement Devices ◽

Main Component

Ground cooling is considered to be one of the passive cooling strategies in buildings although its application is rarely found in Indonesia. Effectiveness of this strategy depend on the ground temperature profiles. Meanwhile, comprehensive data of ground temperature as a basis of design for ground cooling are still rarely found in Indonesia. This research aims to develop the measurement devices for collecting ground temperatures data and to investigate the ground temperatures in different depths (i.e., 1m, 2m, …, 9m). For measurement, an instrumentation system was developed with the main component of Arduino Mega 2560 as microcontroller. T-type thermocouples with diameter of 0, 5mm mounted in the metal cones were used as the temperature sensor and placed at the different depths. The field measurement was conducted from August to November 2019 in Bandung, West Java, Indonesia. This study demonstrated that the developed instrument system had good performance both in measuring and data acquisition. Model equation was developed to predict the ground temperature at certain depth regardless ground materials and humidity level. The results indicated that the ground temperature significantly lower to 5m-depth. However, the reduction of the temperature after 5m was not significant; the deeper the ground, the temperature changes are negligible.

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Proxy Data from Tree-ring Time Series for the Eleven-year Solar Cycle

Publications of the Astronomical Society of Australia ◽

10.1017/s1323358000019275 ◽

1992 ◽

Vol 10 (1) ◽

pp. 64-67 ◽

Cited By ~ 2

Author(s):

J.O. Murphy ◽

T.T. Veblen

Keyword(s):

Solar Cycle ◽

Tree Ring ◽

Direct Evidence ◽

Recent Analysis ◽

Tree Ring Chronology ◽

Proxy Data ◽

Growth Cycles ◽

Temperature Changes ◽

Specific Band ◽

Very High

AbstractOver past decades many attempts have been undertaken to detect a statistically significant 11-year variation in tree-ring widths and thereby provide direct evidence for the influence of solar cycle activity on growth. The data were generally associated with arid sites and were found to contain no signal of any consequence at the equivalent frequency. However, our recent analysis of a tree-ring chronology established from spruce trees growing at a very high sub-alpine site in Colorado, has revealed the presence of a dominant 11-year spectral periodicity over the last 200 years. These growth cycles could arise from temperature changes due to variations in insolation and climate or from variations in direct radiation within a specific band.

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Climatic changes in central and eastern Canada inferred from deep borehole temperature data

Palaeogeography Palaeoclimatology Palaeoecology ◽

10.1016/0031-0182(92)90193-9 ◽

1992 ◽

Vol 98 (2-4) ◽

pp. 129-141 ◽

Cited By ~ 26

Author(s):

Kelin Wang ◽

Trevor J. Lewis ◽

Alan M. Jessop

Keyword(s):

Climatic Changes ◽

Temperature Data ◽

Deep Borehole ◽

Eastern Canada ◽

Borehole Temperature

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A new global reconstruction of temperature changes at the Last Glacial Maximum

Climate of the Past ◽

10.5194/cp-9-367-2013 ◽

2013 ◽

Vol 9 (1) ◽

pp. 367-376 ◽

Cited By ~ 155

Author(s):

J. D. Annan ◽

J. C. Hargreaves

Keyword(s):

Last Glacial Maximum ◽

Climate Models ◽

State Of The Art ◽

Glacial Maximum ◽

Proxy Data ◽

Temperature Changes ◽

Last Glacial ◽

The Last Glacial Maximum ◽

Global Mean ◽

The Last Glacial

Abstract. Some recent compilations of proxy data both on land and ocean (MARGO Project Members, 2009; Bartlein et al., 2011; Shakun et al., 2012), have provided a new opportunity for an improved assessment of the overall climatic state of the Last Glacial Maximum. In this paper, we combine these proxy data with the ensemble of structurally diverse state of the art climate models which participated in the PMIP2 project (Braconnot et al., 2007) to generate a spatially complete reconstruction of surface air (and sea surface) temperatures. We test a variety of approaches, and show that multiple linear regression performs well for this application. Our reconstruction is significantly different to and more accurate than previous approaches and we obtain an estimated global mean cooling of 4.0 ± 0.8 °C (95% CI).

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PMIP4/CMIP6 last interglacial simulations using three different versions of MIROC: importance of vegetation

10.5194/egusphere-egu21-3792 ◽

2021 ◽

Author(s):

Ryouta O'ishi ◽

Wing-Le Chan ◽

Ayako Abe-Ouchi ◽

Sam Sherriff-Tadano ◽

Rumi Ohgaito ◽

...

Keyword(s):

Feedback Mechanism ◽

Climate Feedback ◽

High Latitudes ◽

Last Interglacial ◽

Proxy Data ◽

Area Index ◽

Vegetation Feedback ◽

Temperature Changes ◽

Northern High Latitude ◽

Series Of Experiments

<p>We carry out three sets of last interglacial (LIG) experiments, named lig127k, and of pre-industrial experiments, named piControl, both as part of PMIP4/CMIP6 using three versions of the MIROC model: MIROC4m, MIROC4m-LPJ, and MIROC-ES2L. The results are compared with reconstructions from climate proxy data. All models show summer warming over northern high-latitude land, reflecting the differences between the distributions of the LIG and present-day solar irradiance. Globally averaged temperature changes are &#8722;0.94 K (MIROC4m), &#8722;0.39 K (MIROC4m-LPJ), and &#8722;0.43 K (MIROC-ES2L).<br>Only MIROC4m-LPJ, which includes dynamical vegetation feedback from the change in vegetation distribution, shows annual mean warming signals at northern high latitudes, as indicated by proxy data. In contrast, the latest Earth system model (ESM) of MIROC, MIROC-ES2L, which considers only a partial vegetation effect through the leaf area index, shows no change or even annual cooling over large parts of the Northern Hemisphere. Results from the series of experiments show that the inclusion of full vegetation feedback is necessary for the reproduction of the strong annual warming over land at northern high latitudes. The LIG experimental results show that the warming predicted by models is still underestimated, even with dynamical vegetation, compared to reconstructions from proxy data, suggesting that further investigation and improvement to the climate feedback mechanism are needed.</p>

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Evaluation of Ground Temperature Changes by the Operation of the Geothermal Heat Pump System and Climate Change in Korea

Water ◽

10.3390/w12102931 ◽

2020 ◽

Vol 12 (10) ◽

pp. 2931

Author(s):

Seong-Kyun Kim ◽

Youngmin Lee

Keyword(s):

Climate Change ◽

Heat Pump ◽

Temperature Increase ◽

Ground Temperature ◽

Measured Temperature ◽

Geothermal Heat ◽

Pump System ◽

Temperature Changes ◽

Geothermal Heat Pump

To evaluate long-term temperature changes caused by the operation of a geothermal heat pump (GHP) system, temperatures near borehole heat exchangers (BHEs) of the GHP system in Korea were measured. The temperature measurements showed increasing rates of 0.135 °C/year at a depth of 10 m and 0.118 °C/year at a depth of 50 m for approximately 10 years. Simulations for the analysis of climate change effects on measured temperature fluctuations showed that a rate of temperature increase was 0.010 °C/year at a depth of 50 m owing to changes in surface air temperatures (SATs). From two-dimensional heat transfer simulations, the discharged heat measuring 16.7 W/m in the cooling season and extracted heat measuring 12.4 W/m in the heating season could cause an annual mean temperature increase of 0.109 °C over approximately 10 years. Additionally, results of simulations for future prediction of ground temperatures assuming that the GHP system retains its level of operation showed that in 2050, temperature at a depth of 50 m will increase by approximately 3.00 °C from that in 2005. Thus, balancing the heat discharged into and extracted from the ground by considering climate change to minimize long-term changes in the ground temperature is necessary.

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