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Grant R. Bigg
Department of Geography, University of Sheffield, Sheffield S10 2TN, UK

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Journal article
Published: 09 July 2021 in Sustainability
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Icebergs have long been a threat to shipping in the NW Atlantic and the iceberg season of February to late summer is monitored closely by the International Ice Patrol. However, reliable predictions of the severity of a season several months in advance would be useful for planning monitoring strategies and also for shipping companies in designing optimal routes across the North Atlantic for specific years. A seasonal forecast model of the build-up of seasonal iceberg numbers has recently become available, beginning to enable this longer-term planning of marine operations. Here we discuss extension of this control systems model to include more recent years within the trial ensemble sample set and also increasing the number of measures of the iceberg season that are considered within the forecast. These new measures include the seasonal iceberg total, the rate of change of the seasonal increase, the number of peaks in iceberg numbers experienced within a given season, and the timing of the peak(s). They are predicted by a range of machine learning tools. The skill levels of the new measures are tested, as is the impact of the extensions to the existing seasonal forecast model. We present a forecast for the 2021 iceberg season, predicting a medium iceberg year.

ACS Style

Jennifer Ross; Grant Bigg; Yifan Zhao; Edward Hanna. A Combined Control Systems and Machine Learning Approach to Forecasting Iceberg Flux off Newfoundland. Sustainability 2021, 13, 7705 .

AMA Style

Jennifer Ross, Grant Bigg, Yifan Zhao, Edward Hanna. A Combined Control Systems and Machine Learning Approach to Forecasting Iceberg Flux off Newfoundland. Sustainability. 2021; 13 (14):7705.

Chicago/Turabian Style

Jennifer Ross; Grant Bigg; Yifan Zhao; Edward Hanna. 2021. "A Combined Control Systems and Machine Learning Approach to Forecasting Iceberg Flux off Newfoundland." Sustainability 13, no. 14: 7705.

Special issue article
Published: 22 February 2021 in Journal of Quaternary Science
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The British and Irish Ice Sheet (BIIS) was highly dynamic during the Late Quaternary, with considerable regional differences in the timing and extent of its change. This was reflected in equally variable offshore ice‐rafted debris (IRD) records. Here we reconcile these two records using the FRUGAL intermediate complexity iceberg–climate model, with varying BIIS catchment‐level iceberg fluxes, to simulate change in IRD origin and magnitude along the western European margin at 1000‐year time steps during the height of the last BIIS glaciation (31–6 ka bp). This modelled IRD variability is compared with existing IRD records from the deep ocean at five cores along this margin. There is general agreement of the temporal and spatial IRD variability between observations and model through this period. The Porcupine Bank off northwestern Ireland was confirmed by the modelling as a major dividing line between sites possessing exclusively northern or southern source regions for offshore IRD. During Heinrich events 1 and 2, the cores show evidence of a proportion of North American IRD, more particularly to the south of the British Isles. Modelling supports this southern bias for likely Heinrich impact, but also suggests North American IRD will only reach the British margin in unusual circumstances.

ACS Style

David J. Wilton; Grant R. Bigg; James D. Scourse; Jeremy C. Ely; Chris D. Clark. Exploring the extent to which fluctuations in ice‐rafted debris reflect mass changes in the source ice sheet: a model–observation comparison using the last British–Irish Ice Sheet. Journal of Quaternary Science 2021, 36, 934 -945.

AMA Style

David J. Wilton, Grant R. Bigg, James D. Scourse, Jeremy C. Ely, Chris D. Clark. Exploring the extent to which fluctuations in ice‐rafted debris reflect mass changes in the source ice sheet: a model–observation comparison using the last British–Irish Ice Sheet. Journal of Quaternary Science. 2021; 36 (5):934-945.

Chicago/Turabian Style

David J. Wilton; Grant R. Bigg; James D. Scourse; Jeremy C. Ely; Chris D. Clark. 2021. "Exploring the extent to which fluctuations in ice‐rafted debris reflect mass changes in the source ice sheet: a model–observation comparison using the last British–Irish Ice Sheet." Journal of Quaternary Science 36, no. 5: 934-945.

Journal article
Published: 13 January 2021 in Nature
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The dominant feature of large-scale mass transfer in the modern ocean is the Atlantic meridional overturning circulation (AMOC). The geometry and vigour of this circulation influences global climate on various timescales. Palaeoceanographic evidence suggests that during glacial periods of the past 1.5 million years the AMOC had markedly different features from today1; in the Atlantic basin, deep waters of Southern Ocean origin increased in volume while above them the core of the North Atlantic Deep Water (NADW) shoaled2. An absence of evidence on the origin of this phenomenon means that the sequence of events leading to global glacial conditions remains unclear. Here we present multi-proxy evidence showing that northward shifts in Antarctic iceberg melt in the Indian-Atlantic Southern Ocean (0-50° E) systematically preceded deep-water mass reorganizations by one to two thousand years during Pleistocene-era glaciations. With the aid of iceberg-trajectory model experiments, we demonstrate that such a shift in iceberg trajectories during glacial periods can result in a considerable redistribution of freshwater in the Southern Ocean. We suggest that this, in concert with increased sea-ice cover, enabled positive buoyancy anomalies to 'escape' into the upper limb of the AMOC, providing a teleconnection between surface Southern Ocean conditions and the formation of NADW. The magnitude and pacing of this mechanism evolved substantially across the mid-Pleistocene transition, and the coeval increase in magnitude of the 'southern escape' and deep circulation perturbations implicate this mechanism as a key feedback in the transition to the '100-kyr world', in which glacial-interglacial cycles occur at roughly 100,000-year periods.

ACS Style

Aidan Starr; Ian R. Hall; Stephen Barker; Thomas Rackow; Xu Zhang; Sidney R. Hemming; H. J. L. van der Lubbe; Gregor Knorr; Melissa A. Berke; Grant R. Bigg; Alejandra Cartagena-Sierra; Francisco J. Jiménez-Espejo; Xun Gong; Jens Gruetzner; Nambiyathodi Lathika; Leah J. LeVay; Rebecca S. Robinson; Martin Ziegler. Antarctic icebergs reorganize ocean circulation during Pleistocene glacials. Nature 2021, 589, 236 -241.

AMA Style

Aidan Starr, Ian R. Hall, Stephen Barker, Thomas Rackow, Xu Zhang, Sidney R. Hemming, H. J. L. van der Lubbe, Gregor Knorr, Melissa A. Berke, Grant R. Bigg, Alejandra Cartagena-Sierra, Francisco J. Jiménez-Espejo, Xun Gong, Jens Gruetzner, Nambiyathodi Lathika, Leah J. LeVay, Rebecca S. Robinson, Martin Ziegler. Antarctic icebergs reorganize ocean circulation during Pleistocene glacials. Nature. 2021; 589 (7841):236-241.

Chicago/Turabian Style

Aidan Starr; Ian R. Hall; Stephen Barker; Thomas Rackow; Xu Zhang; Sidney R. Hemming; H. J. L. van der Lubbe; Gregor Knorr; Melissa A. Berke; Grant R. Bigg; Alejandra Cartagena-Sierra; Francisco J. Jiménez-Espejo; Xun Gong; Jens Gruetzner; Nambiyathodi Lathika; Leah J. LeVay; Rebecca S. Robinson; Martin Ziegler. 2021. "Antarctic icebergs reorganize ocean circulation during Pleistocene glacials." Nature 589, no. 7841: 236-241.

Journal article
Published: 20 February 2020 in Quaternary Science Reviews
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The presence of widespread terrigenous material of an ice-rafted origin in Quaternary sediments of the Southern Ocean has been recognized for almost 150 years. Normally this material has been ascribed to deposits from icebergs of continental Antarctic origin. However, during Quaternary glaciations there have been periods of extensive land ice across the sub-Antarctic, on both islands scattered around most of the circumpolar extent of the Southern Ocean, as well as in Patagonia, so providing alternative sources for debris-carrying icebergs. Here a relatively high resolution ocean and iceberg model is used to study the potential distribution of ice-rafted debris (IRD) from the range of past ice sources around the Southern Ocean. It is shown that IRD found in marine cores of the Southern Ocean is most likely to have derived from the Antarctic continent in some regions, particularly of the South Atlantic, but that for extensive regions of the Southern Ocean sub-Antarctic sources of IRD, rather than the continent itself, are more likely. This is particularly true equatorward of 55oS, away from the core continental iceberg outflow from the Weddell gyre. It is argued that the glaciated sub-Antarctic cannot be neglected in explaining past IRD records in the Southern Ocean. This has implications not just for reconstructing the history of glaciation in the sub-Antarctic, but also for understanding past variation in the upper ocean circulation within the Quaternary Southern Ocean.

ACS Style

Grant R. Bigg. The impact of icebergs of sub-Antarctic origin on Southern Ocean ice-rafted debris distributions. Quaternary Science Reviews 2020, 232, 106204 .

AMA Style

Grant R. Bigg. The impact of icebergs of sub-Antarctic origin on Southern Ocean ice-rafted debris distributions. Quaternary Science Reviews. 2020; 232 ():106204.

Chicago/Turabian Style

Grant R. Bigg. 2020. "The impact of icebergs of sub-Antarctic origin on Southern Ocean ice-rafted debris distributions." Quaternary Science Reviews 232, no. : 106204.

Articles
Published: 20 June 2019 in Journal of Operational Oceanography
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The iceberg hazard for the Grand Banks area to the east of Newfoundland varies dramatically from one year to the next. In some years no icebergs penetrate south of 48°N, while in others well over 1000 icebergs enter the main shipping lanes between Europe and NE North America. Advance knowledge of this seasonal hazard would have major implications for ship routing, as well as the resources required for maintaining an effective ice hazard service. Here, a Windowed Error Reduction Ratio control system identification approach is used to forecast the severity of the 2018 iceberg season off Newfoundland, in terms of the predicted number of icebergs crossing 48°N, as well as to hindcast iceberg numbers for 2017. The best estimates are for 766 ± 297 icebergs crossing 48°N before the end of September 2017 and 685 ± 207 for 2018. These are both above the recent observed average of 592 icebergs for that date, and substantially so for 2017. Given the bimodal nature of the annual iceberg number, this means that our predictions for both 2017 and 2018 are for a high iceberg season, with a 71% level of confidence. However, it is most likely that the 2018 iceberg numbers will be somewhat less than 1000, while our higher hindcast for 2017 is consistent with the observed level of 1008. Our verification analysis, covering the 20-year period up to 2016, shows our model's correspondence to the high or low nature of the 48°N iceberg numbers is statistically robust to the 0.05% level, with a skill level of 80%.

ACS Style

Grant R. Bigg; Yifan Zhao; Edward Hanna. Forecasting the severity of the Newfoundland iceberg season using a control systems model. Journal of Operational Oceanography 2019, 14, 24 -36.

AMA Style

Grant R. Bigg, Yifan Zhao, Edward Hanna. Forecasting the severity of the Newfoundland iceberg season using a control systems model. Journal of Operational Oceanography. 2019; 14 (1):24-36.

Chicago/Turabian Style

Grant R. Bigg; Yifan Zhao; Edward Hanna. 2019. "Forecasting the severity of the Newfoundland iceberg season using a control systems model." Journal of Operational Oceanography 14, no. 1: 24-36.

Research article
Published: 06 June 2018 in Science Advances
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Geometries of Early Pleistocene [2.58 to 0.78 million years (Ma) ago] ice sheets in northwest Europe are poorly constrained but are required to improve our understanding of past ocean-atmosphere-cryosphere coupling. Ice sheets are believed to have changed in their response to orbital forcing, becoming, from about 1.2 Ma ago, volumetrically larger and longer-lived. We present a multiproxy data set for the North Sea, extending to over a kilometer below the present-day seafloor, which demonstrates spatially extensive glaciation of the basin from the earliest Pleistocene. Ice sheets repeatedly entered the North Sea, south of 60°N, in water depths of up to ~250 m from 2.53 Ma ago and subsequently grounded in the center of the basin, in deeper water, from 1.87 Ma ago. Despite lower global ice volumes, these ice sheets were near comparable in spatial extent to those of the Middle and Late Pleistocene but possibly thinner and moving over slippery (low basal resistance) beds.

ACS Style

Brice R. Rea; Andrew M. W. Newton; Rachel M. Lamb; Rachel Harding; Grant R. Bigg; Phil Rose; Matteo Spagnolo; Mads Huuse; John M. L. Cater; Stuart Archer; Francis Buckley; Maral Halliyeva; Jane Huuse; David G. Cornwell; Simon H. Brocklehurst; John A. Howell. Extensive marine-terminating ice sheets in Europe from 2.5 million years ago. Science Advances 2018, 4, eaar8327 .

AMA Style

Brice R. Rea, Andrew M. W. Newton, Rachel M. Lamb, Rachel Harding, Grant R. Bigg, Phil Rose, Matteo Spagnolo, Mads Huuse, John M. L. Cater, Stuart Archer, Francis Buckley, Maral Halliyeva, Jane Huuse, David G. Cornwell, Simon H. Brocklehurst, John A. Howell. Extensive marine-terminating ice sheets in Europe from 2.5 million years ago. Science Advances. 2018; 4 (6):eaar8327.

Chicago/Turabian Style

Brice R. Rea; Andrew M. W. Newton; Rachel M. Lamb; Rachel Harding; Grant R. Bigg; Phil Rose; Matteo Spagnolo; Mads Huuse; John M. L. Cater; Stuart Archer; Francis Buckley; Maral Halliyeva; Jane Huuse; David G. Cornwell; Simon H. Brocklehurst; John A. Howell. 2018. "Extensive marine-terminating ice sheets in Europe from 2.5 million years ago." Science Advances 4, no. 6: eaar8327.

Original paper
Published: 02 March 2018 in Natural Hazards
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With the polar regions opening up to more marine activities but iceberg numbers more likely to increase than decline as a result of global warming, the risk from icebergs to shipping and offshore facilities is increasing. The NW Atlantic iceberg hazard has been well monitored by the International Ice Patrol for a century, but many other polar regions have little detailed climatological knowledge of the iceberg risk. Here, we develop a modelling approach to assessing iceberg hazard. This uses the region of the Falklands Plateau and its shipping routes for a case study, but the approach has general geographical applicability and can be used for assessing iceberg hazard for routes or fixed locations. The iceberg risk for a number of locations selected from the main shipping routes in the SW Atlantic is assessed by using an iceberg model, forced by the output from a high-resolution ocean model. The iceberg model was seeded with icebergs around the edge of the modelled region using a number of scenarios for the seeding distribution, based on a combination of idealised, modelled and observed iceberg fluxes from the Southern Ocean. This enabled us to determine measures of iceberg risk linked to a mix of starting location and the likelihood of icebergs being encountered in such a position. For our study area, the main area of iceberg risk is linked to the East Falklands Current, but small, yet nonzero, risk covers much of the east and north of the region.

ACS Style

Grant R. Bigg; Thomas Cropper; Clare K. O’Neill; Alex K. Arnold; A. H. Fleming; R. Marsh; V. Ivchenko; Nicolas Fournier; Mike Osborne; Robin Stephens. A model for assessing iceberg hazard. Natural Hazards 2018, 92, 1113 -1136.

AMA Style

Grant R. Bigg, Thomas Cropper, Clare K. O’Neill, Alex K. Arnold, A. H. Fleming, R. Marsh, V. Ivchenko, Nicolas Fournier, Mike Osborne, Robin Stephens. A model for assessing iceberg hazard. Natural Hazards. 2018; 92 (2):1113-1136.

Chicago/Turabian Style

Grant R. Bigg; Thomas Cropper; Clare K. O’Neill; Alex K. Arnold; A. H. Fleming; R. Marsh; V. Ivchenko; Nicolas Fournier; Mike Osborne; Robin Stephens. 2018. "A model for assessing iceberg hazard." Natural Hazards 92, no. 2: 1113-1136.

Research article
Published: 06 November 2017 in Complexity
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Studying complex dynamic systems is usually very challenging due to limited prior knowledge and high complexity of relationships between interconnected components. Current methods either are like a “black box” that is difficult to understand and relate back to the underlying system or have limited universality and applicability due to too many assumptions. This paper proposes a time-varying Nonlinear Finite Impulse Response model to estimate the multiple features of correlation among measurements including direction, strength, significance, latency, correlation type, and nonlinearity. The dynamic behaviours of correlation are tracked through a sliding window approach based on the Blackman window rather than the simple truncation by a Rectangular window. This method is particularly useful for a system that has very little prior knowledge and the interaction between measurements is nonlinear, time-varying, rapidly changing, or of short duration. Simulation results suggest that the proposed tracking approach significantly reduces the sensitivity of correlation estimation against the window size. Such a method will improve the applicability and robustness of correlation analysis for complex systems. A real application to environmental changing data demonstrates the potential of the proposed method by revealing and characterising hidden information contained within measurements, which is usually “invisible” for conventional methods.

ACS Style

Yifan Zhao; Edward Hanna; Grant R. Bigg; Yitian Zhao. Tracking Nonlinear Correlation for Complex Dynamic Systems Using a Windowed Error Reduction Ratio Method. Complexity 2017, 2017, 1 -14.

AMA Style

Yifan Zhao, Edward Hanna, Grant R. Bigg, Yitian Zhao. Tracking Nonlinear Correlation for Complex Dynamic Systems Using a Windowed Error Reduction Ratio Method. Complexity. 2017; 2017 ():1-14.

Chicago/Turabian Style

Yifan Zhao; Edward Hanna; Grant R. Bigg; Yitian Zhao. 2017. "Tracking Nonlinear Correlation for Complex Dynamic Systems Using a Windowed Error Reduction Ratio Method." Complexity 2017, no. : 1-14.

Journal article
Published: 15 October 2017 in Social Sciences
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Demographic indicators linked to general health have been strongly linked to economic development. However, change in such indicators is also associated with other factors such as climate, water availability, and diet. Here, we use a systems modelling approach, bringing together a range of environmental, economic, dietary, and health factors, to seek possible dominant causes of demographic change across Africa. A continent-wide, north-south transect of countries allows for the exploration of a range of climates, while a longitudinal transect from the Atlantic to the Red Sea provides a range of socio-economic factors within the similar climatic regime of Sahelian Africa. While change in national life expectancy and death rate since 1960 is modelled to be linked to a varying number and type of factors across the transects, the dominant factor in improving these demographic indicators across the continent is food availability. This has been strongly modulated by HIV infection rates in recent decades in some countries.

ACS Style

Hualiang Wei; Grant R. Bigg. The Dominance of Food Supply in Changing Demographic Factors across Africa: A Model Using a Systems Identification Approach. Social Sciences 2017, 6, 122 .

AMA Style

Hualiang Wei, Grant R. Bigg. The Dominance of Food Supply in Changing Demographic Factors across Africa: A Model Using a Systems Identification Approach. Social Sciences. 2017; 6 (4):122.

Chicago/Turabian Style

Hualiang Wei; Grant R. Bigg. 2017. "The Dominance of Food Supply in Changing Demographic Factors across Africa: A Model Using a Systems Identification Approach." Social Sciences 6, no. 4: 122.

Journal article
Published: 01 September 2016 in Nature Geoscience
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ACS Style

Luis P. A. M. Duprat; Grant R. Bigg; David J. Wilton. Erratum: Corrigendum: Enhanced Southern Ocean marine productivity due to fertilization by giant icebergs. Nature Geoscience 2016, 9, 728 -728.

AMA Style

Luis P. A. M. Duprat, Grant R. Bigg, David J. Wilton. Erratum: Corrigendum: Enhanced Southern Ocean marine productivity due to fertilization by giant icebergs. Nature Geoscience. 2016; 9 (9):728-728.

Chicago/Turabian Style

Luis P. A. M. Duprat; Grant R. Bigg; David J. Wilton. 2016. "Erratum: Corrigendum: Enhanced Southern Ocean marine productivity due to fertilization by giant icebergs." Nature Geoscience 9, no. 9: 728-728.

Journal article
Published: 11 January 2016 in Nature Geoscience
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Nutrient input from icebergs can fertilize productivity in the ocean. Ten years of satellite measurements reveal that giant icebergs could be responsible for up to 20% of carbon export to depth in the Southern Ocean.

ACS Style

Luis P. A. M. Duprat; Grant R. Bigg; Luis P. A. M. Duprat Grant R. Bigg David J. Wilton. Enhanced Southern Ocean marine productivity due to fertilization by giant icebergs. Nature Geoscience 2016, 9, 219 -221.

AMA Style

Luis P. A. M. Duprat, Grant R. Bigg, Luis P. A. M. Duprat Grant R. Bigg David J. Wilton. Enhanced Southern Ocean marine productivity due to fertilization by giant icebergs. Nature Geoscience. 2016; 9 (3):219-221.

Chicago/Turabian Style

Luis P. A. M. Duprat; Grant R. Bigg; Luis P. A. M. Duprat Grant R. Bigg David J. Wilton. 2016. "Enhanced Southern Ocean marine productivity due to fertilization by giant icebergs." Nature Geoscience 9, no. 3: 219-221.

Journal article
Published: 01 January 2016 in Cold Regions Science and Technology
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ACS Style

Yifan Zhao; Grant R. Bigg; Steve A. Billings; Edward Hanna; Andrew J. Sole; Hua-Liang Wei; Visakan Kadirkamanathan; David J. Wilton. Inferring the variation of climatic and glaciological contributions to West Greenland iceberg discharge in the twentieth century. Cold Regions Science and Technology 2016, 121, 167 -178.

AMA Style

Yifan Zhao, Grant R. Bigg, Steve A. Billings, Edward Hanna, Andrew J. Sole, Hua-Liang Wei, Visakan Kadirkamanathan, David J. Wilton. Inferring the variation of climatic and glaciological contributions to West Greenland iceberg discharge in the twentieth century. Cold Regions Science and Technology. 2016; 121 ():167-178.

Chicago/Turabian Style

Yifan Zhao; Grant R. Bigg; Steve A. Billings; Edward Hanna; Andrew J. Sole; Hua-Liang Wei; Visakan Kadirkamanathan; David J. Wilton. 2016. "Inferring the variation of climatic and glaciological contributions to West Greenland iceberg discharge in the twentieth century." Cold Regions Science and Technology 121, no. : 167-178.

Journal article
Published: 01 November 2015 in Progress in Oceanography
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We have used a coupled ocean–iceberg model to study the variation in global ocean circulation and North Atlantic iceberg flux from 1900 to 2008. The latter component of the study focused particularly on Greenland icebergs feeding into the Labrador Current and past Newfoundland. The model was forced with daily heat, freshwater and wind fluxes from the Twentieth Century Reanalysis. The reanalysis heat fluxes were shown to be offset from the, shorter, NCEP reanalysis and a grid-point correction was applied to this component of the forcing. The model produces a generally realistic ocean circulation, although with an enhanced Atlantic Meridional Overturning largely due to the forcing. The modelled iceberg flux at 48°N is well correlated with the long-term observed flux when using a modelled iceberg discharge that varies in a similar fashion to the highly variable observed flux at 48°N. From this model we infer changes in the spatial and temporal variability of iceberg calving from western Greenland. During the first third of the twentieth century the majority of modelled icebergs reaching 48°N derive from southern Greenland, while only after 1930 is the traditional perspective of a majority of such icebergs originating from Baffin Bay consistent with model results. Decadal-scale changes in the dominant regional sources are found, with oscillations between western Greenland and northern Baffin Bay. The latter origin was modelled to be most important in the last third of the twentieth century, although west Greenland sources have increased in importance in recent years. The model correctly reproduces the pronounced late spring peak in flux at 48°N for southern Greenland icebergs, but has an approximately six month offset for icebergs from Baffin Bay, most likely due to resolution issues leading to model icebergs not being delayed in shallow coastal waters, whereas in reality they may be grounded for some time or trapped in coastal sea-ice

ACS Style

David J. Wilton; Grant R. Bigg; Edward Hanna. Modelling twentieth century global ocean circulation and iceberg flux at 48°N: implications for west Greenland iceberg discharge. Progress in Oceanography 2015, 138, 194 -210.

AMA Style

David J. Wilton, Grant R. Bigg, Edward Hanna. Modelling twentieth century global ocean circulation and iceberg flux at 48°N: implications for west Greenland iceberg discharge. Progress in Oceanography. 2015; 138 ():194-210.

Chicago/Turabian Style

David J. Wilton; Grant R. Bigg; Edward Hanna. 2015. "Modelling twentieth century global ocean circulation and iceberg flux at 48°N: implications for west Greenland iceberg discharge." Progress in Oceanography 138, no. : 194-210.

Journal article
Published: 10 April 2014 in Weather
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ACS Style

Grant R. Bigg; David J. Wilton. Iceberg risk in the Titanic year of 1912: was it exceptional? Weather 2014, 69, 100 -104.

AMA Style

Grant R. Bigg, David J. Wilton. Iceberg risk in the Titanic year of 1912: was it exceptional? Weather. 2014; 69 (4):100-104.

Chicago/Turabian Style

Grant R. Bigg; David J. Wilton. 2014. "Iceberg risk in the Titanic year of 1912: was it exceptional?" Weather 69, no. 4: 100-104.

Journal article
Published: 01 April 2014 in Deep Sea Research Part I: Oceanographic Research Papers
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Seasonal coastal upwelling was analyzed along the NW African coastline (11–35°N) from 1981 to 2012. Upwelling magnitudes are calculated by wind speed indices, sea-surface temperature indices and inferred from meteorological station, sea-surface height and vertical water column transport data. A permanent annual upwelling regime is documented across 21–35°N and a seasonal regime across 12–19°N, in accordance with the climatology of previous studies. Upwelling regions were split into three zones: (1) the Mauritania–Senegalese upwelling zone (12–19°N), (2) the strong permanent annual upwelling zone (21–26°N) and (3) the weak permanent upwelling zone (26–35°N). We find compelling evidence in our various indices for the Bakun upwelling intensification hypothesis due to a significant coastal summer wind speed increase, resulting in an increase in upwelling-favorable wind speeds north of 20°N and an increase in downwelling-favorable winds south of 20°N. The North Atlantic Oscillation plays a leading role in modifying interannual variability during the other seasons (autumn–spring), with its influence dominating in winter. The East Atlantic pattern shows a strong correlation with upwelling during spring, while El Niño Southern Oscillation and Atlantic Multi-decadal Oscillation teleconnections were not found. A disagreement between observationally-based wind speed products and reanalysis-derived data is explored. A modification to the Bakun upwelling intensification hypothesis for NW Africa is presented, which accounts for the latitudinal divide in summer wind regimes

ACS Style

Thomas Cropper; Edward Hanna; Grant R. Bigg. Spatial and temporal seasonal trends in coastal upwelling off Northwest Africa, 1981–2012. Deep Sea Research Part I: Oceanographic Research Papers 2014, 86, 94 -111.

AMA Style

Thomas Cropper, Edward Hanna, Grant R. Bigg. Spatial and temporal seasonal trends in coastal upwelling off Northwest Africa, 1981–2012. Deep Sea Research Part I: Oceanographic Research Papers. 2014; 86 ():94-111.

Chicago/Turabian Style

Thomas Cropper; Edward Hanna; Grant R. Bigg. 2014. "Spatial and temporal seasonal trends in coastal upwelling off Northwest Africa, 1981–2012." Deep Sea Research Part I: Oceanographic Research Papers 86, no. : 94-111.

Journal article
Published: 04 October 2013 in Quaternary Science Reviews
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We examine variations in the ice-rafted sources for sediments in the Iceland/East Greenland offshore marine archives by utilizing a sediment unmixing model and link the results to a coupled iceberg-ocean model. Surface samples from around Iceland and along the E/NE Greenland shelf are used to define potential sediment sources, and these are examined within the context of the down-core variations in mineralogy in the <2 mm sediment fraction from a transect of cores across Denmark Strait. A sediment unmixing model is used to estimate the fraction of sediment <2 mm off NW and N Iceland exported across Denmark Strait; this averaged between 10 and 20%. Both the sediment unmixing model and the coupled iceberg-ocean model are consistent in finding that the fraction of “far-travelled” sediments in the Denmark Strait environs is overwhelmingly of local, mid-East Greenland, provenance, and therefore with a significant cross-channel component to their travel. The Holocene record of ice-rafted sediments denotes a three-part division of the Holocene in terms of iceberg sediment transport with a notable increase in the process starting ca 4000 cal yr BP. This latter increase may represent the re-advance during the Neoglacial period of land-terminating glaciers on the Geikie Plateau to become marine-terminating. The contrast in spectral signals between these cores and the 1500-yr cycle at VM28-14, just south of the Denmark Strait, combined with the coupled iceberg-model results, leads us to speculate that the signal at VM28-14 reflects pulses in overflow waters, rather than an ice-rafted signal.

ACS Style

John T. Andrews; Grant R. Bigg; David J. Wilton. Holocene ice-rafting and sediment transport from the glaciated margin of East Greenland (67–70°N) to the N Iceland shelves: detecting and modelling changing sediment sources. Quaternary Science Reviews 2013, 91, 204 -217.

AMA Style

John T. Andrews, Grant R. Bigg, David J. Wilton. Holocene ice-rafting and sediment transport from the glaciated margin of East Greenland (67–70°N) to the N Iceland shelves: detecting and modelling changing sediment sources. Quaternary Science Reviews. 2013; 91 ():204-217.

Chicago/Turabian Style

John T. Andrews; Grant R. Bigg; David J. Wilton. 2013. "Holocene ice-rafting and sediment transport from the glaciated margin of East Greenland (67–70°N) to the N Iceland shelves: detecting and modelling changing sediment sources." Quaternary Science Reviews 91, no. : 204-217.

Journal article
Published: 10 August 2013 in Estuarine, Coastal and Shelf Science
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In this study, the principal controls on the coastal environment around the Pacific island of Okinawa, typical of the many mountainous islands of the sub-tropical and tropical northwest Pacific in the arc from Melanesia to the Ryukyu Islands, are investigated. Two principal satellite remote sensing data products were used to observe properties at regional-scale and in the Okinawan coastal zone: (1) AVHRR sea surface temperature (SST) for 1985–2006 and (2) a SeaWiFS ocean colour variable to estimate combined sediment and chlorophyll-a loadings for 1998–2006, along with direct observations (e.g. climatological data, river discharge, suspended sediment and typhoon tracks). Analysis suggested that coastal SST is strongly influenced by the outer ocean SST, indicating a regional control. However, the local winds, with associated summer rainfall and copious sediment-laden run-off, had a significant secondary impact. Typhoons are also an important factor leading to ocean colour variation. Along the western coastal zone of Okinawa, the winter East Asian Monsoon causes significant upwelling and seafloor sediment removal, while terrestrial impact is a significant secondary control in summer on ocean colour variability via sediment-laden river run-off. Previously noted changes in the magnitude of extreme rainfall events in the area suggest that sediment delivery to the coastal zones of islands in the region has been increasing in recent decades, providing a combined climate and terrestrial impact on the coastal environment. Although typhoons and heavy rainfall are episodic events, appropriate land management on the many hilly and mountainous islands of the sub-tropical northwestern Pacific is needed if such events are not to lead to deterioration, and decrease of resilience, of coastal ecosystems.

ACS Style

Takeharu Ikema; Robert Bryant; Grant R. Bigg. Environmental controls at multiple scales for the western Pacific: An Okinawan case study. Estuarine, Coastal and Shelf Science 2013, 128, 52 -63.

AMA Style

Takeharu Ikema, Robert Bryant, Grant R. Bigg. Environmental controls at multiple scales for the western Pacific: An Okinawan case study. Estuarine, Coastal and Shelf Science. 2013; 128 ():52-63.

Chicago/Turabian Style

Takeharu Ikema; Robert Bryant; Grant R. Bigg. 2013. "Environmental controls at multiple scales for the western Pacific: An Okinawan case study." Estuarine, Coastal and Shelf Science 128, no. : 52-63.

Journal article
Published: 29 June 2013 in Evolutionary Ecology
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The concept of species surviving through quaternary climatic extremes by retreating to glacial refugia, and then evolving genetically during re-population movements of the following interglacial, has been in the literature for over 40 years. Recently, advances in genetic analysis have enabled this concept to be validated and theories regarding population expansions and contractions to be built. For the major Northern Hemisphere species of cod, Gadus morhua (Atlantic cod) and Gadus macrocephalus (Pacific cod), genetic analysis has suggested retreat to separate refugia on both sides of their respective ocean basins during the last glacial period. Ecosystem niche modelling has previously confirmed that environmental conditions during the last glacial were compatible with the existence of these separate refugia for Atlantic cod. Here it is shown that such modelling also confirms a reduced core glacial distribution for G. macrocephalus, but probable refugia on either side of the Pacific. Existing mitochondrial DNA analyses suggest two separate glacial populations in the northwest Pacific, which modelling confirms, with predicted separate marine refugia in the land-locked Sea of Japan basin and the Sea of Okhotsk. Existing mitochondrial DNA for the northeast Pacific populations is less conclusive regarding whether there were one or two separate refugia off this coast, and their location. Using environmental niche models this study shows the glacial NE Pacific environment could support two marine refugia, one centred in the Aleutians/Gulf of Alaska and the other off British Columbia. The intervening Cordilleran Ice Sheet, and the glacially sub-aerial and ice-free Queen Charlotte Islands shelf, is hypothesised to have constrained exchange between glacial stocks either side of the Islands. The postulated southern marine refugium is off-shore from an established terrestrial refugium, suggesting greater dependence of species and ecosystems during environmental change. An earth system approach to evolutionary change could enhance understanding of past and future ecosystems.

ACS Style

Grant Robert Bigg. Environmental confirmation of multiple ice age refugia for Pacific cod, Gadus macrocephalus. Evolutionary Ecology 2013, 28, 177 -191.

AMA Style

Grant Robert Bigg. Environmental confirmation of multiple ice age refugia for Pacific cod, Gadus macrocephalus. Evolutionary Ecology. 2013; 28 (1):177-191.

Chicago/Turabian Style

Grant Robert Bigg. 2013. "Environmental confirmation of multiple ice age refugia for Pacific cod, Gadus macrocephalus." Evolutionary Ecology 28, no. 1: 177-191.

Journal article
Published: 31 December 2012 in Global and Planetary Change
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The marine-based Atlantic periphery of the last NW European Ice Sheet experienced significant advances and retreats of its marine sector during its existence. It therefore had considerable potential to intermittently inject freshwater or ice pulses to the North Atlantic. These European inputs had poorly known consequences for ocean circulation and climate. Here we examine the history of the western margin of the European Ice Sheet, from 34 to 15 cal ka BP, and use a combination of modelling and proxy evidence to explore the impact on the North Atlantic of the fresh water and iceberg injections that accompanied phases of retreat of the marine sector of the NW European Ice Sheet. We find that the lack of geographical synchronicity in the responses of the different components of the 3000 km long sector meant that the scale of the climate consequences of ice discharge most likely remained regional, except during the final deglaciation phase, around 17–15 cal ka BP. At this time, as the later component of the recently introduced concept of an extended Heinrich event H1, both proxy and modelling evidence suggest rapid sector collapse led to partial shut-down of the Atlantic overturning and a basin-wide cooling.

ACS Style

Grant R Bigg; Chris Clark; Sarah Greenwood; Haflidi Haflidason; Anna Hughes; Richard Levine; A. Nygård; Hans Petter Sejrup. Sensitivity of the North Atlantic circulation to break-up of the marine sectors of the NW European ice sheets during the last Glacial: A synthesis of modelling and palaeoceanography. Global and Planetary Change 2012, 98-99, 153 -165.

AMA Style

Grant R Bigg, Chris Clark, Sarah Greenwood, Haflidi Haflidason, Anna Hughes, Richard Levine, A. Nygård, Hans Petter Sejrup. Sensitivity of the North Atlantic circulation to break-up of the marine sectors of the NW European ice sheets during the last Glacial: A synthesis of modelling and palaeoceanography. Global and Planetary Change. 2012; 98-99 ():153-165.

Chicago/Turabian Style

Grant R Bigg; Chris Clark; Sarah Greenwood; Haflidi Haflidason; Anna Hughes; Richard Levine; A. Nygård; Hans Petter Sejrup. 2012. "Sensitivity of the North Atlantic circulation to break-up of the marine sectors of the NW European ice sheets during the last Glacial: A synthesis of modelling and palaeoceanography." Global and Planetary Change 98-99, no. : 153-165.

Journal article
Published: 27 March 2012 in Meteorological Applications
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Cold air drainage is a characteristic of hilly or mountainous terrain and can have significant impact on agricultural or horticultural activities. This paper considers a range of synoptic and topographic factors that could affect the phenomenon of cold air drainage, through an exploration of its characteristics in the Peak District of central England, showing that cold air drainage events can occur at any time of the year, with summer events being even more frequent than those usually noticed in winter. The occurrence of such events is related to the local topography, and particularly the correspondence to hollows and local valleys on the scale of 0.5-1 km, rather than on the scale of the principal drainage routes in the region. In contrast to some previous studies, synoptic and local weather conditions were not found to be strong indicators of cold air drainage events. It is also shown that under suitable conditions cold air drainage can overcome the effects of the urban heat island. © 2012 Royal Meteorological Society

ACS Style

Grant R. Bigg; Stephen M. Wise; Edward Hanna; Damien Mansell; Robert Bryant; Alick Howard. Synoptic climatology of cold air drainage in the Derwent Valley, Peak District, UK. Meteorological Applications 2012, 21, 161 -170.

AMA Style

Grant R. Bigg, Stephen M. Wise, Edward Hanna, Damien Mansell, Robert Bryant, Alick Howard. Synoptic climatology of cold air drainage in the Derwent Valley, Peak District, UK. Meteorological Applications. 2012; 21 (2):161-170.

Chicago/Turabian Style

Grant R. Bigg; Stephen M. Wise; Edward Hanna; Damien Mansell; Robert Bryant; Alick Howard. 2012. "Synoptic climatology of cold air drainage in the Derwent Valley, Peak District, UK." Meteorological Applications 21, no. 2: 161-170.