Rob Massom

• PhD Scott Polar Research Institute (Univ. of Cambridge, UK)
• Australian Antarctic Division

Antarctic sea ice and its snow cover play a pivotal role in regulating the global climate system. Understanding the intricate interplay between atmospheric dynamics, ocean circulation and mixed-layer properties, and sea ice is essential for predicting future climate change scenarios. This study investigates the relationship between atmospheric cond...

Antarctic landfast sea ice (fast ice) is stationary sea ice that is attached to the coast, grounded icebergs, ice shelves, or other protrusions on the continental shelf. Fast ice forms in narrow (generally up to 200 km wide) bands, and ranges in thickness from centimeters to tens of meters. In most regions, it forms in autumn, persists through the...

Sea ice is a key habitat in the high latitude Southern Ocean and is predicted to change in its extent, thickness and duration in coming decades. The sea-ice cover is instrumental in mediating ocean–atmosphere exchanges and provides an important substrate for organisms from microbes and algae to predators. Antarctic krill, Euphausia superba, is reli...

In the marginal ice zone (MIZ), where ocean waves and sea ice interact, waves can produce flows of water across ice floe surfaces in a process known as wave overwash. Overwash potentially influences wave propagation characteristics, floe thermodynamics, and floe surface biological and chemical processes. However, the extent of the MIZ affected by o...

The Southern Ocean plays a central role in the Earth System by connecting the Earth’s ocean basins, and it is a crucial link between the deep ocean, surface ocean and atmosphere. Hence, the ongoing changes in the Southern Ocean impact global climate, rates of sea level rise, biogeochemical cycles and ecological systems. Yet, understanding of the ca...

The Antarctic marginal ice zone (MIZ) is a highly dynamic region where sea ice interacts with ocean surface waves generated in ice-free areas of the Southern Ocean. Improved large-scale (satellite-based) estimates of MIZ extent and variability are crucial for understanding atmosphere–ice–ocean interactions and biological processes and detection of...

A model of the extent of overwash into fields of sea ice is developed. The extent model builds on previous work modelling overwash of a single floe by regular waves to include irregular waves and many random floes. The extent model is validated against laboratory experiments. The model is used to study the the extent of overwash into fields of panc...

Sea ice can attenuate Southern Ocean swell before it reaches Antarctic ice shelves and imposes flexural stresses, which promote calving of outer ice-shelf margins and influence ice shelf stability. An algorithm is developed to identify sea ice-free corridors that connect the open Southern Ocean to Antarctic ice shelves from daily satellite sea ice...

Increased exposure of Antarctica’s coastal environment to open ocean and waves due to loss of a protective sea-ice “buffer” has important ramifications for ice-shelf stability, coastal erosion, important ice-ocean-atmosphere interactions and shallow benthic ecosystems. Here, we introduce a climate and environmental metric based on the ongoing long-...

The Antarctic marginal ice zone (MIZ) is a highly dynamic region where sea ice interacts with ocean surface waves generated in ice-free areas of the Southern Ocean. Improved large-scale (satellite-based) estimates of MIZ width and variability are crucial for understanding atmosphere-ice-ocean interactions and biological processes, and detection of...

Landfast sea ice (fast ice) is an important though poorly understood component of the cryosphere on the Antarctic continental shelf, where it plays a key role in atmosphere–ocean–ice-sheet interaction and coupled ecological and biogeochemical processes. Here, we present a first in-depth baseline analysis of variability and change in circum-Antarcti...

The Antarctic outer coastal margin (i.e. the coastline itself or the terminus or front of ice shelves, whichever is adjacent to the ocean) is a key interface between the ice sheet and terrestrial environments and the Southern Ocean. Its physical configuration (including both length scale of variation, orientation, and aspect) has direct bearing on...

Increased exposure of Antarctica’s coastal environment to ocean waves due to loss of a protective sea-ice “buffer” has important ramifications for ice-shelf stability, coastal erosion, important ice-ocean-atmosphere interactions and shallow benthic ecosystems. Here, we introduce an important new climate and environmental metric based on the ongoing...

Presentation at the AMS 16th Conference on Polar Meteorology and Oceanography, 1-4 June 2021.

Landfast sea ice (fast ice) is an important though poorly-understood component of the cryosphere on the Antarctic continental shelf, where it plays a key role in atmosphere-ocean-ice sheet interaction and coupled ecological and biogeochemical processes. Here, we present a first in-depth baseline analysis of variability and change in circum-Antarcti...

Landfast sea ice (fast ice) is an important component of the Antarctic nearshore marine environment, where it strongly modulates ice sheet–ocean–atmosphere interactions and biological and biogeochemical processes, forms a key habitat, and affects logistical operations. Given the wide-ranging importance of Antarctic fast ice and its sensitivity to c...

This study reports the occurrence of intense atmospheric rivers (ARs) during the two large Weddell Polynya events in November 1973 and September 2017 and investigates their role in the opening events via their enhancement of sea ice melt. Few days before the polynya openings, persistent ARs maintained a sustained positive total energy flux at the s...

Landfast sea ice (fast ice) is an important component of the Antarctic nearshore marine environment, where it strongly modulates ice sheet-ocean-atmosphere interactions and biological and biogeochemical processes, forms a key habitat, and affects logistical operations. Given the wide-ranging importance of Antarctic fast ice and its sensitivity to c...

Antarctic coastal polynyas serve as crucially-important sea-ice “factories” and are (in certain cases) of global significance as sites of Antarctic Bottom Water (AABW) formation e.g., the Cape Darnley Polynya (CDP) in East Antarctica. As such, understanding change and variability in their behaviour, and the factors responsible, is a high priority i...

The Antarctic outer coastal margin (i.e., the coastline itself, or the terminus/front of ice shelves, whichever is adjacent to the ocean) is a key interface between the ice-sheet and terrestrial environments and the Southern Ocean. Its physical configuration (including both length scale of variation and orientation/aspect) has direct bearing on sev...

The Southern Ocean is disproportionately important in its effect on the Earth system, impacting climatic, biogeochemical, and ecological systems, which makes recent observed changes to this system cause for global concern. The enhanced understanding and improvements in predictive skill needed for understanding and projecting future states of the So...

Satellite-derived Antarctic sea ice extent has displayed a slight upward since 1979, but with strong temporal and regional variability—the drivers of which are poorly understood. Here, we conduct numerical experiments with a circum-Antarctic ocean–sea ice–ice shelf model driven by realistic atmospheric surface boundary conditions to examine the fac...

Snow is the most reflective, and also the most insulative, natural material on Earth. Consequently, it is an integral part of the sea-ice and climate systems. However, the spatial and temporal heterogeneities of snow pose challenges for observing, understanding and modelling those systems under anthropogenic warming. Here, we survey the snow–ice sy...

Antarctic sea ice trends have to date been linked to surface winds, through sea ice motion and atmospheric thermal advection. This paper analyzes sea ice volume in 10 Coupled Model Intercomparison Project Phase 5 (CMIP5) model configurations under pre-industrial and historical climate forcings, to compare the relative importance of ice motion and t...

Overall Antarctic sea ice extent in the 2016 spring attained a record minimum for the satellite period (1979–2016), presenting an abrupt departure from the record maxima in previous years and the slight upward trend since 1979. In 2016 the atmospheric conditions over the Southern Ocean changed dramatically from the prevailing cold and westerly anom...

In 2017, the dominant greenhouse gases released into Earth's atmosphere-carbon dioxide, methane, and nitrous oxide-reached new record highs. The annual global average carbon dioxide concentration at Earth's surface for 2017 was 405.0 ± 0.1 ppm, 2.2 ppm greater than for 2016 and the highest in the modern atmospheric measurement record and in ice cor...

We show how imagery from uncalibrated airborne cameras can be used to reconstruct the snow/air interface on Antarctic sea ice, using data collected on the SIPEX-II research voyage during austral spring 2012. Imagery collected by an airborne surveying package was used to develop a 3D surface model using a structure-from-motion approach. This model w...

Understanding the causes of recent catastrophic ice shelf disintegrations is a crucial step towards improving coupled models of the Antarctic Ice Sheet and predicting its future state and contribution to sea-level rise. An overlooked climate-related causal factor is regional sea ice loss. Here we show that for the disintegration events observed (th...

Fast ice is an important component of Antarctic coastal marine ecosystems, providing a prolific habitat for ice algal communities. This work examines the relationships between normalized difference indices (NDI) calculated from under-ice radiance measurements and sea ice algal biomass and snow thickness for Antarctic fast ice. While this technique...

In contrast to a strong decrease in Arctic sea ice extent, overall Antarctic sea ice extent has modestly increased since 1979. Several hypotheses have been proposed for the net Antarctic sea ice expansion, including atmosphere/ocean circulation and temperature changes, sea ice-atmospheric-ocean feedback, increased precipitation, and enhanced basal...

Ch 7. Regional Climates: f. Europe and the Middle East

The spreading of Dense Shelf Water (DSW) from Antarctic coastal margins to lower latitudes plays a vital role in the ocean thermohaline circulation and the global climate system. Through enhanced localized sea ice production in Antarctic coastal polynyas, cold and saline DSW is formed over the continental shelf regions as a precursor to Antarctic B...

Investigating ecological relationships between predators and their environment is essential to understand the response of marine ecosystems to climate variability and change. This is particularly true in polar regions, where sea ice (a sensitive climate variable) plays a crucial yet highly dynamic and variable role in how it influences the whole ma...

Contrasting regional changes in Southern Ocean sea ice have occurred over the last 30 years with distinct regional effects on ecosystem structure and function. Quantifying how Antarctic predators respond to such changes provides the context for predicting how climate variability/change will affect these assemblages into the future. Over an 11-year...

Ocean-cryosphere interactions along the Adélie and George V Land (AGVL) coast are investigated using a coupled ocean-sea ice-ice shelf model. The dominant feature of the Mertz Glacier Tongue (MGT), located at approximately 145°E, was a highly productive winter coastal polynya system, until its calving in February 2010 dramatically changed the regio...

Snow is a crucial and integral component of the sea ice system. It insulates the ice to retard the rate of thermodynamic ice thickening. At the same time, it contributes directly to sea-ice thickening through snow-ice formation, which can occur where the weight of the snow overburden leads to surface flooding. Snow has unique optical properties tha...

In 2012, Antarctic sea-ice coverage was marked by weak annual-mean climate anomalies that consisted of opposing anomalies early and late in the year (some setting new records) which were interspersed by near-average conditions for most of the austral autumn and winter. Here, we investigate the ocean-ice atmosphere system off East Antarctica, prior...

Over the past 37 years, satellite records show an increase in Antarctic sea ice cover that is most pronounced in the period of sea ice growth. This trend is dominated by increased sea ice coverage in the western Ross Sea, and is mitigated by a strong decrease in the Bellingshausen and Amundsen seas. The trends in sea ice areal coverage are accompan...

Deriving the snow depth on Antarctic sea ice is a key factor in estimating sea-ice thickness distributions from space or airborne altimeters. Using a linear regression to model snow depth from observed ‘total freeboard’, or the snow/ice surface elevation relative to sea level is an efficient and promising method for the estimation of snow depth for...

In late winter-early spring 2012, the second Sea Ice Physics and Ecosystems Experiment (SIPEX II) was conducted off Wilkes Land, East Antarctica, onboard R/V Aurora Australis. The sea-ice conditions were characterized by significantly thick first-year ice and snow, trapping the ship for about 10 days in the near coastal region. The deep snow cover...

Our current knowledge of broad-scale patterns of primary production in the Southern Ocean is derived from satellite ocean-colour estimates of chlorophyll a (Chl a) in the open ocean, typically in spring-summer. Here, we provide evidence that large-scale intra-ice phytoplankton surface aggregation occur off the coast of Antarctica during austral aut...

Abstract Recent attention has focused on accelerated glacial losses along the Amundsen Sea coast that result from changes in atmosphere and ocean circulation, with sea ice playing a mediating but not well-understood role. Here, we investigated how sea ice has changed in the Amundsen Sea over the period of 1979 to 2014, focusing on spatio-temporal c...

The Mertz Glacier tongue (MGT) in East Antarctica lost ~55% of its floating length in February 2010, when it calved large tabular iceberg C28 (78 x 35 km). We analyse the behavior of the MGT over the preceding 12 years using a variety of satellite data (SAR and Landsat imagery, and ICESat laser altimetry). Contact of its northwestern tip with the e...

Observations of Southern Hemisphere sea ice from passive microwave satellite measurements show that a new record maximum extent of 19.58 × 106km2 was reached on 30 September 2013; the extent is just over two standard deviations above the 1979-2012 mean and follows a similar record (19.48 × 106km2) in 2012. On the record day in 2013, sea-ice extent...

Accurately measuring and monitoring the thickness distribution of thin ice is crucial for accurate estimation of ocean atmosphere heat fluxes and rates of ice production and salt flux in ice-affected oceans. Here we present results from helicopter-borne brightness temperature (TB) measurements in the Southern Ocean in October 2012 and in the Sea of...

Antarctic and Southern Ocean science is vital to understanding natural variability, the processes that govern global change and the role of humans in the Earth and climate system. The potential for new knowledge to be gained from future Antarctic science is substantial. Therefore, the international Antarctic community came together to ‘scan the hor...

Horizon scan methodologies 1,2,3,4 were customized for the Antarctic Science Horizon Scan aiming for broad community engagement and transparent decision-making. A database of 866 scientific questions was generated by two open community-wide, on-line solicitations. Submitted questions were expected to: i) be answerable by an achievable research desi...

Mahlon C. Kennicutt II, Steven L. Chown and colleagues outline the most pressing questions in southern polar research, and call for greater collaboration and environmental protection in the region.

Mahlon C. Kennicutt II, Steven L.

Antarctic and Southern Ocean (ASO) marine ecosystems have been changing for at least the last 30 years, including in response to increasing ocean temperatures and changes in the extent and seasonality of sea ice; the magnitude and direction of these changes differ between regions around Antarctica that could see populations of the same species chan...

For the first time in serveral years, the El Nino-Southern Oscillation did not dominate regional climate conditions around the globe. A weak La Ni a dissipated to ENSOneutral conditions by spring, and while El Nino appeared to be emerging during summer, this phase never fully developed as sea surface temperatures in the eastern conditions. Neverthe...

Sea ice is an important component of the Earth’s cryosphere. Observed and expected changes in the Earth’s climate system at the high latitudes are found to be partly linked to changes in the sea ice cover. The main characteristics describing the sea ice cover are A) the sea ice area fraction, B) the sea ice thickness, C) the sea ice motion, D) the...

Recent analyses have shown that significant changes have occurred in patterns of sea ice seasonality in West Antarctica since 1979, with wide-ranging climatic, biological and biogeochemical consequences. Here, we provide the first detailed report on long-term change and variability in annual timings of sea ice advance, retreat and resultant ice sea...

A new methodology for coincident floe-scale measurements of the surface elevation, snow depth, and ice draft (the thickness below the water line) of Antarctic sea ice has been demonstrated during two recent research voyages: the Australian-led Sea Ice Physics and Ecosystem Experiment II (SIPEX II) to East Antarctica in September–November 2012 and t...

As the world's ice diminishes in the face of climate change-from the dramatic decline in Arctic sea ice, to thinning at the margins of both the Greenland and Antarctic ice sheets, to retreating mountain glaciers the world over-Antarctic sea ice presents something of a paradox. The trend in total sea ice extent in the Antarctic has remained steady,...

1] This bi-polar analysis resolves ice edge changes on space/time scales relevant for investigating seasonal ice-ocean feedbacks and focuses on spatio-temporal changes in the timing of annual sea ice retreat and advance over 1979/ 80 to 2010/11. Where Arctic sea ice decrease is fastest, the sea ice retreat is now nearly 2 months earlier and subsequ...

This study presents the first continuous, high spatiotemporal resolution time series of landfast sea ice extent along the East Antarctic coast for the period March 2000-December 2008. The time series was derived from consecutive 20-day cloud-free Moderate Resolution Imaging Spectroradiometer (MODIS) composite images. Fast ice extent across the East...

While feature tracking of sea ice using cross-correlation methods on pairs of satellite Synthetic Aperture Radar (SAR) images has been extensively carried out in the Arctic, this is not the case in the Antarctic. This is due to the dynamic nature of Antarctic pack ice, its microwave signature, the tendency for SAR swath paths to be poorly aligned w...

A Geographic Information System (GIS)-based investigation into the interannual variability of sea ice concentration was conducted in the Dumont d’Urville Sea off the Terre Adélie coastline, south of 65°S and between 139 and 146°E. Sea ice concentration data derived from Advanced Microwave Scanning Radiometer-EOS (AMSR-E) data were analysed for the...

In the area to the east of Mertz Glacier in East Antarctica, sea ice forms and often remains for many years. It is typically held in place by grounded icebergs and attached to the coastline to form large expanses of fast ice. In some cases the fast ice has remained in place for decades and attained a great thickness of tens of metres. This ice comp...

In February 2010, the tongue of the Mertz Glacier calved, releasing an 80x30km iceberg. We had anticipated this calving event and started observing it's development as well as gathering data to monitor the dynamics of the glacier upstream. Here, we present the main characteristics of Mertz Glacier in the context of this calving event. In addition t...

The Sea Ice Physics and Ecosystem eXperiment (SIPEX) was conducted in the East Antarctic pack ice zone between 115-130°E from 9 September – 11 October, 2007. In situ measurements of sea-ice and snow properties were conducted at 15 ice stations, together with ship-based ASPeCt observations. The ice and snow thickness varied considerably in different...

The properties of snow on East Antarctic sea ice off Wilkes Land were examined during the Sea Ice Physics and Ecosystem Experiment (SIPEX) in late winter of 2007, focusing on the interaction with sea ice. This observation includes 11 transect lines for the measurement of ice thickness, freeboard, and snow depth, 50 snow pits on 13 ice floes, and di...

In October 2003 a campaign on board the Australian icebreaker Aurora Australis had the objective to validate standard Aqua Advanced Microwave Scanning Radiometer (AMSR-E) sea-ice products. Additionally, the satellite laser altimeter on the Ice, Cloud and land Elevation Satellite (ICESat) was in operation. To capture the large-scale information on t...

The 2007 International Polar Year (IPY) in the Antarctic was distinguished by strong regional and seasonal ice-atmosphere-ocean anomalies associated with an overall weakening of the prevailing westerly circulation. Here we assess the ice-atmosphere-ocean conditions leading up to and during two IPY field campaigns that took place in early spring (Se...

In austral spring 2007, two meso-scale (of the order of 10–100km) drifting buoy arrays were deployed to investigate the sea-ice kinematics off East Antarctica during the Sea Ice Physics and Ecosystem eXperiment (SIPEX). Deployment locations were within the one oceanic surface-drift regime with similarly high ice concentrations, the two arrays were...

The properties of snow on East Antarctic sea ice off Wilkes Land were examined during the Sea Ice Physics and Ecosystem Experiment (SIPEX) in late winter of 2007, focusing on the interaction with sea ice. This observation includes 11 transect lines for the measurement of ice thickness, freeboard, and snow depth, 50 snow pits on 13 ice floes, and di...

A method to generate high spatio-temporal resolution maps of landfast sea ice from cloud-free MODIS composite imagery is presented. Visible (summertime) and thermal infrared (wintertime) cloud-free 20-day MODIS composite images are used as the basis for these maps, augmented by AMSR-E ASI sea-ice concentration composite images (when MODIS composite...

The Mertz Glacier tongue (MGT), East Antarctica, has a large area of multi-year fast sea ice (MYFI) attached to its eastern edge. We use various satellite data sets to study the extent, age, and thickness of the MYFI and how it interacts with the MGT. We estimate its age to be at least 25 years and its thickness to be 10-55 m; this is an order of m...

Although Antarctic sea ice is undergoing a slight increase in overall extent, major regional changes are occurring in its spatio-temporal characteristics (most notably in sea ice seasonality). Biologically significant aspects of Antarctic sea ice are evaluated, emphasising the importance of scale and thermodynamics versus dynamics. Changing sea ice...

IntroductionThe intimate and complex relationship between snow and sea iceGeneral characteristics of snow on iceThe temporal evolution of the snow packSnow pack propertiesSnow depth distributionRemote-sensing considerationsEcological significance of snowThe outlookAcknowledgementsReferences

In mid-February 2010 a massive iceberg designated B09B collided with the Mertz Glacier tongue - a section of the glacier that protruded about 100 km from the Antarctic coastline at about 145 E. The collision precipitated the calving of another massive iceberg, C28, from the tongue, measuring 78 km long and between 33 and 39 km wide. This calving ev...

This paper presents details of techniques for generating thermal infrared and visible composite images from the cloud-free portions of temporally closely spaced MODerate resolution Imaging Spectroradiometer (MODIS) images, with a focus on studies of landfast sea ice along the East Antarctic coast. Composite image inclusion criteria are based on mod...

During austral spring 2003, mesoscale sea ice drift and deformation off East Antarctica were investigated using in situ data from a nine-buoy array. Upon deployment, the array comprised an area of about 4000 km2 with a mean ice concentration of 96%. Half-hourly sea ice velocities were coherent across all buoys at zonal (meridional) separations of l...

Techniques are presented for generating thermal infrared and visible composite images from cloud-free portions of MODIS (MODerate resolution Imaging Spectroradiometer) images closely spaced in time, with a focus on studies of landfast sea ice along the East Antarctic coast. Composite image inclusion criteria are based on modified MODIS EOS cloud ma...