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S Moustafa - One of the best experts on this subject based on the ideXlab platform.
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efficient meltwater Drainage through supraglacial streams and rivers on the southwest greenland ice sheet
Proceedings of the National Academy of Sciences of the United States of America, 2015Co-Authors: Laurence C Smith, V W Chu, Kang Yang, C J Gleason, L H Pitcher, A K Rennermalm, Carl J Legleiter, A Behar, B T Overstreet, S MoustafaAbstract:Thermally incised meltwater channels that flow each summer across melt-prone Surfaces of the Greenland ice sheet have received little direct study. We use high-resolution WorldView-1/2 satellite mapping and in situ measurements to characterize supraglacial water storage, Drainage pattern, and discharge across 6,812 km(2) of southwest Greenland in July 2012, after a record melt event. Efficient Surface Drainage was routed through 523 high-order stream/river channel networks, all of which terminated in moulins before reaching the ice edge. Low Surface water storage (3.6 ± 0.9 cm), negligible impoundment by supraglacial lakes or topographic depressions, and high discharge to moulins (2.54-2.81 cm⋅d(-1)) indicate that the Surface Drainage system conveyed its own storage volume every <2 d to the bed. Moulin discharges mapped inside ∼52% of the source ice watershed for Isortoq, a major proglacial river, totaled ∼41-98% of observed proglacial discharge, highlighting the importance of supraglacial river Drainage to true outflow from the ice edge. However, Isortoq discharges tended lower than runoff simulations from the Modele Atmospherique Regional (MAR) regional climate model (0.056-0.112 km(3)⋅d(-1) vs. ∼0.103 km(3)⋅d(-1)), and when integrated over the melt season, totaled just 37-75% of MAR, suggesting nontrivial subglacial water storage even in this melt-prone region of the ice sheet. We conclude that (i) the interior Surface of the ice sheet can be efficiently drained under optimal conditions, (ii) that digital elevation models alone cannot fully describe supraglacial Drainage and its connection to subglacial systems, and (iii) that predicting outflow from climate models alone, without recognition of subglacial processes, may overestimate true meltwater export from the ice sheet to the ocean.
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efficient meltwater Drainage through supraglacial streams and rivers on the southwest greenland ice sheet
Proceedings of the National Academy of Sciences of the United States of America, 2015Co-Authors: Laurence C Smith, V W Chu, Kang Yang, C J Gleason, L H Pitcher, A K Rennermalm, Carl J Legleiter, A Behar, B T Overstreet, S MoustafaAbstract:Meltwater runoff from the Greenland ice sheet is a key contributor to global sea level rise and is expected to increase in the future, but it has received little observational study. We used satellite and in situ technologies to assess Surface Drainage conditions on the southwestern ablation Surface after an extreme 2012 melting event. We conclude that the ice sheet Surface is efficiently drained under optimal conditions, that digital elevation models alone cannot fully describe supraglacial Drainage and its connection to subglacial systems, and that predicting outflow from climate models alone, without recognition of subglacial processes, may overestimate true meltwater release from the ice sheet.
Laurence C Smith - One of the best experts on this subject based on the ideXlab platform.
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efficient meltwater Drainage through supraglacial streams and rivers on the southwest greenland ice sheet
Proceedings of the National Academy of Sciences of the United States of America, 2015Co-Authors: Laurence C Smith, V W Chu, Kang Yang, C J Gleason, L H Pitcher, A K Rennermalm, Carl J Legleiter, A Behar, B T Overstreet, S MoustafaAbstract:Thermally incised meltwater channels that flow each summer across melt-prone Surfaces of the Greenland ice sheet have received little direct study. We use high-resolution WorldView-1/2 satellite mapping and in situ measurements to characterize supraglacial water storage, Drainage pattern, and discharge across 6,812 km(2) of southwest Greenland in July 2012, after a record melt event. Efficient Surface Drainage was routed through 523 high-order stream/river channel networks, all of which terminated in moulins before reaching the ice edge. Low Surface water storage (3.6 ± 0.9 cm), negligible impoundment by supraglacial lakes or topographic depressions, and high discharge to moulins (2.54-2.81 cm⋅d(-1)) indicate that the Surface Drainage system conveyed its own storage volume every <2 d to the bed. Moulin discharges mapped inside ∼52% of the source ice watershed for Isortoq, a major proglacial river, totaled ∼41-98% of observed proglacial discharge, highlighting the importance of supraglacial river Drainage to true outflow from the ice edge. However, Isortoq discharges tended lower than runoff simulations from the Modele Atmospherique Regional (MAR) regional climate model (0.056-0.112 km(3)⋅d(-1) vs. ∼0.103 km(3)⋅d(-1)), and when integrated over the melt season, totaled just 37-75% of MAR, suggesting nontrivial subglacial water storage even in this melt-prone region of the ice sheet. We conclude that (i) the interior Surface of the ice sheet can be efficiently drained under optimal conditions, (ii) that digital elevation models alone cannot fully describe supraglacial Drainage and its connection to subglacial systems, and (iii) that predicting outflow from climate models alone, without recognition of subglacial processes, may overestimate true meltwater export from the ice sheet to the ocean.
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efficient meltwater Drainage through supraglacial streams and rivers on the southwest greenland ice sheet
Proceedings of the National Academy of Sciences of the United States of America, 2015Co-Authors: Laurence C Smith, V W Chu, Kang Yang, C J Gleason, L H Pitcher, A K Rennermalm, Carl J Legleiter, A Behar, B T Overstreet, S MoustafaAbstract:Meltwater runoff from the Greenland ice sheet is a key contributor to global sea level rise and is expected to increase in the future, but it has received little observational study. We used satellite and in situ technologies to assess Surface Drainage conditions on the southwestern ablation Surface after an extreme 2012 melting event. We conclude that the ice sheet Surface is efficiently drained under optimal conditions, that digital elevation models alone cannot fully describe supraglacial Drainage and its connection to subglacial systems, and that predicting outflow from climate models alone, without recognition of subglacial processes, may overestimate true meltwater release from the ice sheet.
Richard A Fenner - One of the best experts on this subject based on the ideXlab platform.
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the impact of natural flood management on the performance of Surface Drainage systems a case study in the calder valley
Journal of Hydrology, 2020Co-Authors: Charlie Ferguson, Richard A FennerAbstract:Abstract The evaluation of Natural Flood Management (NFM) has traditionally focused on the ability of interventions to mitigate downstream fluvial flooding by attenuating catchment response. However, the justification for the implementation of NFM projects at a local level is often supported by other benefits provided by such interventions (e.g. improvements to water quality or biodiversity). This study investigates the potential for a further, largely unrecognised, benefit. It is suggested that, by moderating water levels in downstream watercourses, upstream interventions could also help sustain free discharge from Drainage outfalls, thereby improving the performance of urban Surface Drainage systems. A coupled modelling methodology is applied to the upper Calder Valley and the Surface Drainage in an area of the downstream town of Todmorden. The rural response and subsequent NFM interventions are characterised using hydrological (Dynamic TOPMODEL) and hydraulic (HEC-RAS) models. Several downstream Surface Drainage systems are then incorporated using an Infoworks ICM model to examine their response to changes in outfall inundation. The results suggest that catchment-scale tree planting and in-channel woody debris create modest benefits for downstream Surface Drainage systems. Under frequent storm events (e.g. a 1 in 10 year storm), the inundation of low-lying outfalls is completely removed. As storm severity increases (and Surface flooding becomes an issue), impact from upstream NFM attenuation on outfall inundation durations diminishes significantly. However, the slight delay in rural response allows more water to escape Surface systems, increasing the effective capacity of networks and reducing Surface flooding. For instance, outfall inundation during an estimated 20 year event is delayed by 0.5 hours, which results in up to 25% reduction in Surface flood volumes. While the benefits are limited in extent, this modelling indicates that NFM can help improve downstream Surface Drainage performance.
V W Chu - One of the best experts on this subject based on the ideXlab platform.
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efficient meltwater Drainage through supraglacial streams and rivers on the southwest greenland ice sheet
Proceedings of the National Academy of Sciences of the United States of America, 2015Co-Authors: Laurence C Smith, V W Chu, Kang Yang, C J Gleason, L H Pitcher, A K Rennermalm, Carl J Legleiter, A Behar, B T Overstreet, S MoustafaAbstract:Thermally incised meltwater channels that flow each summer across melt-prone Surfaces of the Greenland ice sheet have received little direct study. We use high-resolution WorldView-1/2 satellite mapping and in situ measurements to characterize supraglacial water storage, Drainage pattern, and discharge across 6,812 km(2) of southwest Greenland in July 2012, after a record melt event. Efficient Surface Drainage was routed through 523 high-order stream/river channel networks, all of which terminated in moulins before reaching the ice edge. Low Surface water storage (3.6 ± 0.9 cm), negligible impoundment by supraglacial lakes or topographic depressions, and high discharge to moulins (2.54-2.81 cm⋅d(-1)) indicate that the Surface Drainage system conveyed its own storage volume every <2 d to the bed. Moulin discharges mapped inside ∼52% of the source ice watershed for Isortoq, a major proglacial river, totaled ∼41-98% of observed proglacial discharge, highlighting the importance of supraglacial river Drainage to true outflow from the ice edge. However, Isortoq discharges tended lower than runoff simulations from the Modele Atmospherique Regional (MAR) regional climate model (0.056-0.112 km(3)⋅d(-1) vs. ∼0.103 km(3)⋅d(-1)), and when integrated over the melt season, totaled just 37-75% of MAR, suggesting nontrivial subglacial water storage even in this melt-prone region of the ice sheet. We conclude that (i) the interior Surface of the ice sheet can be efficiently drained under optimal conditions, (ii) that digital elevation models alone cannot fully describe supraglacial Drainage and its connection to subglacial systems, and (iii) that predicting outflow from climate models alone, without recognition of subglacial processes, may overestimate true meltwater export from the ice sheet to the ocean.
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efficient meltwater Drainage through supraglacial streams and rivers on the southwest greenland ice sheet
Proceedings of the National Academy of Sciences of the United States of America, 2015Co-Authors: Laurence C Smith, V W Chu, Kang Yang, C J Gleason, L H Pitcher, A K Rennermalm, Carl J Legleiter, A Behar, B T Overstreet, S MoustafaAbstract:Meltwater runoff from the Greenland ice sheet is a key contributor to global sea level rise and is expected to increase in the future, but it has received little observational study. We used satellite and in situ technologies to assess Surface Drainage conditions on the southwestern ablation Surface after an extreme 2012 melting event. We conclude that the ice sheet Surface is efficiently drained under optimal conditions, that digital elevation models alone cannot fully describe supraglacial Drainage and its connection to subglacial systems, and that predicting outflow from climate models alone, without recognition of subglacial processes, may overestimate true meltwater release from the ice sheet.
Kang Yang - One of the best experts on this subject based on the ideXlab platform.
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efficient meltwater Drainage through supraglacial streams and rivers on the southwest greenland ice sheet
Proceedings of the National Academy of Sciences of the United States of America, 2015Co-Authors: Laurence C Smith, V W Chu, Kang Yang, C J Gleason, L H Pitcher, A K Rennermalm, Carl J Legleiter, A Behar, B T Overstreet, S MoustafaAbstract:Thermally incised meltwater channels that flow each summer across melt-prone Surfaces of the Greenland ice sheet have received little direct study. We use high-resolution WorldView-1/2 satellite mapping and in situ measurements to characterize supraglacial water storage, Drainage pattern, and discharge across 6,812 km(2) of southwest Greenland in July 2012, after a record melt event. Efficient Surface Drainage was routed through 523 high-order stream/river channel networks, all of which terminated in moulins before reaching the ice edge. Low Surface water storage (3.6 ± 0.9 cm), negligible impoundment by supraglacial lakes or topographic depressions, and high discharge to moulins (2.54-2.81 cm⋅d(-1)) indicate that the Surface Drainage system conveyed its own storage volume every <2 d to the bed. Moulin discharges mapped inside ∼52% of the source ice watershed for Isortoq, a major proglacial river, totaled ∼41-98% of observed proglacial discharge, highlighting the importance of supraglacial river Drainage to true outflow from the ice edge. However, Isortoq discharges tended lower than runoff simulations from the Modele Atmospherique Regional (MAR) regional climate model (0.056-0.112 km(3)⋅d(-1) vs. ∼0.103 km(3)⋅d(-1)), and when integrated over the melt season, totaled just 37-75% of MAR, suggesting nontrivial subglacial water storage even in this melt-prone region of the ice sheet. We conclude that (i) the interior Surface of the ice sheet can be efficiently drained under optimal conditions, (ii) that digital elevation models alone cannot fully describe supraglacial Drainage and its connection to subglacial systems, and (iii) that predicting outflow from climate models alone, without recognition of subglacial processes, may overestimate true meltwater export from the ice sheet to the ocean.
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efficient meltwater Drainage through supraglacial streams and rivers on the southwest greenland ice sheet
Proceedings of the National Academy of Sciences of the United States of America, 2015Co-Authors: Laurence C Smith, V W Chu, Kang Yang, C J Gleason, L H Pitcher, A K Rennermalm, Carl J Legleiter, A Behar, B T Overstreet, S MoustafaAbstract:Meltwater runoff from the Greenland ice sheet is a key contributor to global sea level rise and is expected to increase in the future, but it has received little observational study. We used satellite and in situ technologies to assess Surface Drainage conditions on the southwestern ablation Surface after an extreme 2012 melting event. We conclude that the ice sheet Surface is efficiently drained under optimal conditions, that digital elevation models alone cannot fully describe supraglacial Drainage and its connection to subglacial systems, and that predicting outflow from climate models alone, without recognition of subglacial processes, may overestimate true meltwater release from the ice sheet.
