We review the sampling and results of the radiocarbon dating of the archaeological cloth known as... more We review the sampling and results of the radiocarbon dating of the archaeological cloth known as the Shroud of Turin, in the light of recent statistical analyses of both published and raw data. The statistical analyses highlight an inter-laboratory heterogeneity of the means and a monotone spatial variation of the ages of subsamples that suggest the presence of contaminants unevenly removed by the cleaning pretreatments. We consider the significance and overall impact of the statistical analyses on assessing the reliability of the dating results and the design of correct sampling. These analyses suggest that the 1988 radiocarbon dating does not match the current accuracy requirements. Should this be the case, it would be interesting to know the accurate age of the Shroud of Turin. Taking into account the whole body of scientific data, we discuss whether it makes sense to date the Shroud again.
... The low salinity occurs because of the very large influx of fresh water into the Arctic Ocean... more ... The low salinity occurs because of the very large influx of fresh water into the Arctic Ocean from large river systems such as the Ob', Lena, Yenisei and Mackenzie which drain huge areas of the Asian and North American continents. Fig. ...
Renewed political and commercial interest in the resources of the Arctic, the reduction in the ex... more Renewed political and commercial interest in the resources of the Arctic, the reduction in the extent and thickness of sea ice, and the recent failings that led to the Deepwater Horizon oil spill, have prompted industry and its regulatory agencies, governments, local communities and NGOs to look at all aspects of Arctic oil spill countermeasures with fresh eyes. This paper provides an overview of present oil spill response capabilities and technologies for ice-covered waters, as well as under potential future conditions driven by a changing climate. Though not an exhaustive review, we provide the key research results for oil spill response from knowledge accumulated over many decades, including significant review papers that have been prepared as well as results from recent laboratory tests, field programmes and modelling work. The three main areas covered by the review are as follows: oil weathering and modelling; oil detection and monitoring; and oil spill response techniques.
A study of sea ice in the northern Weddell Sea was done, relating the ice motion, determined usin... more A study of sea ice in the northern Weddell Sea was done, relating the ice motion, determined using an array of satellite-tracked drifters, deployed into ice floes, to parameters describing the nature of the ice cover, obtained from an analysis of Advanced Very High Resolution Radiometer (AVHRR) imagery. It was found that the ice motion was predominantly wind-driven, responding to the passage of low-pressure systems across the area. The correlation length of the strain field over the entire measurement period was around 200 km. At high concentrations the ice responded as a rigid body with coherent motion, but below a concentration of around 93%, differential motion occurred. The nature of the ice motion was found to depend upon the lead parameters, with low values of pure convergence and divergence and larger values of vorticity and deformation of the ice field. The vorticity was found to be well correlated with the atmospheric pressure, with a time lag of less than 3 h, implying an ...
Data from instruments placed on tabular Antarctic icebergs show that they flex, heave, and roll i... more Data from instruments placed on tabular Antarctic icebergs show that they flex, heave, and roll in response to ocean waves. One iceberg was monitored for 13 months in the Weddell Sea by an automatic data collection platform deployed by the Norwegian Antarctic Research Expedition 1978-79. The temperature sensors demonstrated burial by snow-fall during autumn and winter, but melting during the following summer led to a net annual surface mass balance of -0.1 m water equivalent and to snow and firn temperatures being raised to the melting point. Strain and tilt instruments showed flexure and tilt with main frequencies around 15 to 20 s, but short sampling periods made it difficult to conduct comprehensive statistical analysis of the data.
ABSTRACT The Ross Sea polynya is a complex oceanographic feature with a strong influence on the h... more ABSTRACT The Ross Sea polynya is a complex oceanographic feature with a strong influence on the heat balances of the Ross Sea. The opening of the Ross Sea polynya depends on three main factors: the katabatic surges associated with the cyclogenesys events on the Siple coast, the katabatic flow down the glaciers in the Eastern Ross Sea and the katabatic winds blowing from the Transantarctic Mountains, which are turned aside by Ross Island (Bromwich et al., 1998). In this work, the polynya opening and closure in 1999 is studied. A flux model (Biggs et al. 2000) is applied to a few case study in order to describe the polynya behaviour. Heat fluxes and sea ice production will be evaluated by using bulk formulae. The meteorological input for the calculations are provided by the European Center for Medium-range Weather Forecasting. Sea ice concentration data will be used in order to validate the model. Daily ice concentration data were retrieved by using the Sea Lion algorithm to obtain maps of the polynya area with a spatial resolution of 12.5x12.5km2 (Kern and Heygster, 2001; Kern, 2001). This is achieved using the polarization difference of 85GHz brightness temperatures acquired by the Special Sensor Microwave/Imager (SSM/I). This study focuses on the Ross Sea Polynya, but nevertheless the Terra Nova Bay polynya case will be investigated.
ABSTRACT In August 2004 the Autosub-II AUV, operating off NE Greenland, carried out the first mul... more ABSTRACT In August 2004 the Autosub-II AUV, operating off NE Greenland, carried out the first multibeam digital terrain mapping of the sea ice underside, using a Kongsberg EM2000 sonar. We show some of the high-quality imagery from the experiment, and discuss its implications for ice thickness mapping and other applications. In April 2007 the second such mapping experiment took place, but this time using a small ice-launched Gavia AUV, equipped with a GeoSwath 500 kHz interferometric sonar system. Gavia could be launched and recovered manually through 3 x 1 m holes while Autosub required a ship and a crane. The greater range of Autosub is contrasted with the greater flexibility of Gavia in multisensor programs. The Gavia imagery shows the morphological distinctions between first-year (FY) and multi-year (MY) ice undersides, the contrast between the shapes of FY and MY ridges, and the appearance of refrozen leads. Ice drafts were validated by drilling, and it was found that ridge slope statistics and local probability density functions (PDFs) of draft could be derived with high precision.
We review the sampling and results of the radiocarbon dating of the archaeological cloth known as... more We review the sampling and results of the radiocarbon dating of the archaeological cloth known as the Shroud of Turin, in the light of recent statistical analyses of both published and raw data. The statistical analyses highlight an inter-laboratory heterogeneity of the means and a monotone spatial variation of the ages of subsamples that suggest the presence of contaminants unevenly removed by the cleaning pretreatments. We consider the significance and overall impact of the statistical analyses on assessing the reliability of the dating results and the design of correct sampling. These analyses suggest that the 1988 radiocarbon dating does not match the current accuracy requirements. Should this be the case, it would be interesting to know the accurate age of the Shroud of Turin. Taking into account the whole body of scientific data, we discuss whether it makes sense to date the Shroud again.
... The low salinity occurs because of the very large influx of fresh water into the Arctic Ocean... more ... The low salinity occurs because of the very large influx of fresh water into the Arctic Ocean from large river systems such as the Ob', Lena, Yenisei and Mackenzie which drain huge areas of the Asian and North American continents. Fig. ...
Renewed political and commercial interest in the resources of the Arctic, the reduction in the ex... more Renewed political and commercial interest in the resources of the Arctic, the reduction in the extent and thickness of sea ice, and the recent failings that led to the Deepwater Horizon oil spill, have prompted industry and its regulatory agencies, governments, local communities and NGOs to look at all aspects of Arctic oil spill countermeasures with fresh eyes. This paper provides an overview of present oil spill response capabilities and technologies for ice-covered waters, as well as under potential future conditions driven by a changing climate. Though not an exhaustive review, we provide the key research results for oil spill response from knowledge accumulated over many decades, including significant review papers that have been prepared as well as results from recent laboratory tests, field programmes and modelling work. The three main areas covered by the review are as follows: oil weathering and modelling; oil detection and monitoring; and oil spill response techniques.
A study of sea ice in the northern Weddell Sea was done, relating the ice motion, determined usin... more A study of sea ice in the northern Weddell Sea was done, relating the ice motion, determined using an array of satellite-tracked drifters, deployed into ice floes, to parameters describing the nature of the ice cover, obtained from an analysis of Advanced Very High Resolution Radiometer (AVHRR) imagery. It was found that the ice motion was predominantly wind-driven, responding to the passage of low-pressure systems across the area. The correlation length of the strain field over the entire measurement period was around 200 km. At high concentrations the ice responded as a rigid body with coherent motion, but below a concentration of around 93%, differential motion occurred. The nature of the ice motion was found to depend upon the lead parameters, with low values of pure convergence and divergence and larger values of vorticity and deformation of the ice field. The vorticity was found to be well correlated with the atmospheric pressure, with a time lag of less than 3 h, implying an ...
Data from instruments placed on tabular Antarctic icebergs show that they flex, heave, and roll i... more Data from instruments placed on tabular Antarctic icebergs show that they flex, heave, and roll in response to ocean waves. One iceberg was monitored for 13 months in the Weddell Sea by an automatic data collection platform deployed by the Norwegian Antarctic Research Expedition 1978-79. The temperature sensors demonstrated burial by snow-fall during autumn and winter, but melting during the following summer led to a net annual surface mass balance of -0.1 m water equivalent and to snow and firn temperatures being raised to the melting point. Strain and tilt instruments showed flexure and tilt with main frequencies around 15 to 20 s, but short sampling periods made it difficult to conduct comprehensive statistical analysis of the data.
ABSTRACT The Ross Sea polynya is a complex oceanographic feature with a strong influence on the h... more ABSTRACT The Ross Sea polynya is a complex oceanographic feature with a strong influence on the heat balances of the Ross Sea. The opening of the Ross Sea polynya depends on three main factors: the katabatic surges associated with the cyclogenesys events on the Siple coast, the katabatic flow down the glaciers in the Eastern Ross Sea and the katabatic winds blowing from the Transantarctic Mountains, which are turned aside by Ross Island (Bromwich et al., 1998). In this work, the polynya opening and closure in 1999 is studied. A flux model (Biggs et al. 2000) is applied to a few case study in order to describe the polynya behaviour. Heat fluxes and sea ice production will be evaluated by using bulk formulae. The meteorological input for the calculations are provided by the European Center for Medium-range Weather Forecasting. Sea ice concentration data will be used in order to validate the model. Daily ice concentration data were retrieved by using the Sea Lion algorithm to obtain maps of the polynya area with a spatial resolution of 12.5x12.5km2 (Kern and Heygster, 2001; Kern, 2001). This is achieved using the polarization difference of 85GHz brightness temperatures acquired by the Special Sensor Microwave/Imager (SSM/I). This study focuses on the Ross Sea Polynya, but nevertheless the Terra Nova Bay polynya case will be investigated.
ABSTRACT In August 2004 the Autosub-II AUV, operating off NE Greenland, carried out the first mul... more ABSTRACT In August 2004 the Autosub-II AUV, operating off NE Greenland, carried out the first multibeam digital terrain mapping of the sea ice underside, using a Kongsberg EM2000 sonar. We show some of the high-quality imagery from the experiment, and discuss its implications for ice thickness mapping and other applications. In April 2007 the second such mapping experiment took place, but this time using a small ice-launched Gavia AUV, equipped with a GeoSwath 500 kHz interferometric sonar system. Gavia could be launched and recovered manually through 3 x 1 m holes while Autosub required a ship and a crane. The greater range of Autosub is contrasted with the greater flexibility of Gavia in multisensor programs. The Gavia imagery shows the morphological distinctions between first-year (FY) and multi-year (MY) ice undersides, the contrast between the shapes of FY and MY ridges, and the appearance of refrozen leads. Ice drafts were validated by drilling, and it was found that ridge slope statistics and local probability density functions (PDFs) of draft could be derived with high precision.
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Papers by Peter Wadhams