Changing distributions of sea ice melt and meteoric water west of the Antarctic Peninsula

Meredith, Michael P.; Stammerjohn, Sharon; Venables, Hugh J.; Ducklow, Hugh W.; Martinson, Douglas G.; Iannuzzi, Richard A.; Leng, Melanie J.; Wessem, Jan Melchior van; Reijmer, C. H.; Barrand, Nicholas E.

doi:10.1016/j.dsr2.2016.04.019

Cited by 64 publications

(102 citation statements)

References 76 publications

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“…The pronounced variability and change observed in atmospheric forcing, sea ice dynamics, glacial retreat, freshwater distribution and ocean physics along the WAP have a strong impact on primary production, community composition, ecosystem functioning, ocean chemistry and oceanatmosphere exchanges of heat and dissolved gases (e.g. Ducklow et al 2013;Meredith et al 2017;Venables and Meredith 2014). Improving our understanding of this dynamic system is of high scientific priority as a result of significant variability and change in the physical environment, important biological and biogeochemical consequences, and documented sensitivity to and feedbacks on climate change.…”

Section: Introductionmentioning

confidence: 99%

Variability and change in the west Antarctic Peninsula marine system: Research priorities and opportunities

Henley

Schofield

Hendry

et al. 2019

Progress in Oceanography

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The west Antarctic Peninsula (WAP) region has undergone significant changes in temperature and seasonal ice dynamics since the mid-twentieth century, with strong impacts on the regional ecosystem, ocean chemistry and hydrographic properties. Changes to these long-term trends of warming and sea ice decline have been observed in the 21 st century, but their consequences for ocean physics, chemistry and the ecology of the high-productivity shelf ecosystem are yet to be fully established. The WAP shelf is important for regional krill stocks and higher trophic levels, whilst the degree of variability and change in the physical environment and documented biological and biogeochemical responses make this a model system for how climate and sea ice changes might restructure high-latitude ecosystems. Although this region is arguably the best-measured and bestunderstood shelf region around Antarctica, significant gaps remain in spatial and temporal data capable of resolving the atmosphere-ice-ocean-ecosystem feedbacks that control the dynamics and evolution of this complex polar system. Here we summarise the current state of knowledge regarding the key mechanisms and interactions regulating the physical, biogeochemical and biological processes at work, the ways in which the shelf environment is changing, and the ecosystem response to the changes underway. We outline the overarching cross-disciplinary priorities for future research, as well as the most important discipline-specific objectives. Underpinning these priorities and objectives is the need to better-define the causes, magnitude and timescales of variability and change at all levels of the system. A combination of traditional and innovative approaches will be critical to addressing these priorities and developing a coordinated observing system for the WAP shelf, which is required to detect and elucidate change into the future.

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Section: Introductionmentioning

confidence: 99%

Variability and change in the west Antarctic Peninsula marine system: Research priorities and opportunities

Henley

Schofield

Hendry

et al. 2019

Progress in Oceanography

Self Cite

109

115

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“…Both δ 18 O and salinity were usually utilized as tracers to solve the freshwater budget for seawater mass balance in polar oceans (e.g., Meredith et al, , ; Östlund & Hut, ). Some early sea ice mass balance studies also used both δ 18 O and salinity as tracers (e.g., Jeffries et al, ; Lange et al, ).…”

Section: Methodsmentioning

confidence: 99%

Stable Isotope Clues to the Formation and Evolution of Refrozen Melt Ponds on Arctic Sea Ice

et al. 2018

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Sea ice is one of the determining parameters of the climate system. The presence of melt ponds on the surface of Arctic sea ice plays a critical role in the mass balance of sea ice. A total of nine cores was collected from multiyear ice refrozen melt ponds and adjacent hummocks during the 2015 Arctic Sea State research cruise. The depth profiles of water isotopes, salinity, and ice texture for these sea ice cores were examined to provide information about the development of refrozen melt ponds and water balance generation processes, which are otherwise difficult to acquire. The presence of meteoric water with low oxygen isotope values as relatively thin layers indicates melt pond water stability and little mixing during formation and refreezing. The hydrochemical characteristics of refrozen melt pond and seawater depth profiles indicate little snowmelt enters the upper ocean during melt pond refreezing. Due to the seasonal characters of deuterium excess for Arctic precipitation, water balance calculations utilizing two isotopic tracers (oxygen isotope and deuterium excess) suggest that besides the melt of snow cover, the precipitation input in the melt season may also play a role in the evolution of melt ponds. The dual‐isotope mixing model developed here may become more valuable in a future scenario of increasing Arctic precipitation. The layers of meteoric origin were found at different depths in the refrozen melt pond ice cores. Surface topography information collected at several core sites was examined for possible explanations of different structures of refrozen melt ponds.

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“…Sea ice retreat from the preceding winter was late and the contribution of sea ice meltwater to the water column during summer was, although modest at all times, the highest (2.8%) recorded in the RaTS program ( Figure 4B; Legge et al, 2017;Meredith et al, 2017). Oxygen isotope data from the surface and at 2 m depth showed an influx of sea ice melt after December 13th, continuing to at least the end of February.…”

Section: Freshwater Originmentioning

confidence: 99%

Assessing Drivers of Coastal Primary Production in Northern Marguerite Bay, Antarctica

Rozema

Kulk

Veldhuis³

et al. 2017

Front. Mar. Sci.

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The coastal ocean of the climatically-sensitive west Antarctic Peninsula is experiencing changes in the physical and (photo)chemical properties that strongly affect the phytoplankton. Consequently, a shift from diatoms, pivotal in the Antarctic food web, to more mobile and smaller flagellates has been observed. We seek to identify the main drivers behind primary production (PP) without any assumptions beforehand to obtain the best possible model of PP. We employed a combination of field measurements and modeling to discern and quantify the influences of variability in physical, (photo)chemical, and biological parameters on PP in northern Marguerite Bay. Field data of high-temporal resolution (November 2013-March 2014) collected at a long-term monitoring site here were combined with estimates of PP derived from photosynthesis-irradiance incubations and modeled using mechanistic and statistical models. Daily PP varied greatly and averaged 1,764 mg C m −2 d −1 with a maximum of 6,908 mg C m −2 d −1 after the melting of sea ice and the likely release of diatoms concentrated therein. A non-assumptive random forest model (RF) with all possibly relevant parameters (M RFmax ) showed that variability in PP was best explained by light availability and chlorophyll a followed by physical (temperature, mixed layer depth, and salinity) and chemical (phosphate, total nitrogen, and silicate) water column properties. The predictive power from the relative abundances of diatoms, cryptophytes, and haptophytes (as determined by pigment fingerprinting) to PP was minimal. However, the variability in PP due to changes in species composition was most likely underestimated due to the contrasting strategies of these phytoplankton groups as we observed significant negative relations between PP and the relative abundance of flagellates groups. Our reduced model (M RFmin ) showed how light availability, chlorophyll a, and total nitrogen concentrations can be used to obtain the best estimate of PP (R 2 = 0.93). The resulting estimates from our models suggest summer PP to have been between 214.4 and 176.1 g C m −2 . Through the employment of a modeling technique without any assumptions apart from a representative sampling strategy, we showed and estimated how PP in this climatically sensitive and changing region can best be predicted and described.

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Changing distributions of sea ice melt and meteoric water west of the Antarctic Peninsula

Cited by 64 publications

References 76 publications

Variability and change in the west Antarctic Peninsula marine system: Research priorities and opportunities

Variability and change in the west Antarctic Peninsula marine system: Research priorities and opportunities

Stable Isotope Clues to the Formation and Evolution of Refrozen Melt Ponds on Arctic Sea Ice

Assessing Drivers of Coastal Primary Production in Northern Marguerite Bay, Antarctica

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