Antarctic ice-shelf meltwater outflows in satellite radar imagery: ground-truthing and basal channel observations DOI Creative Commons
Jakob Stanley Hamann, Thomas Arney, James D. Kirkham

et al.

Journal of Glaciology, Journal Year: 2024, Volume and Issue: unknown, P. 1 - 13

Published: Oct. 14, 2024

Abstract Ice shelves regulate the flow of Antarctic ice sheet toward ocean and its contribution to sea-level rise. Accurately monitoring basal surface melting is therefore essential for predicting sheet's response climatic warming. In this study, we utilize Sentinel-1A synthetic aperture radar satellite imagery combined with shipboard measurements water temperature salinity investigate presence surficial meltwater plumes along coastline. Our approach reveals a strong correlation between areas pronounced low backscatter extending from significant decreases in salinity, suggesting meltwater-enriched waters. We propose that signature outflows caused by stable stratification upper column, driven density contrasts buoyant, low-salinity current shear reduce Bragg scattering waves. The resulting smooth surfaces were observed adjacent expression deep channels, documented helicopter survey part Bellingshausen Sea edge. present high-temporal resolution as tool identifying release beneath shelves, capable all-weather, day-and-night imaging.

Language: Английский

Application of HY-2B Satellite Data to Retrieve Snow Depth on Antarctic Sea Ice DOI Creative Commons
Qing Ji, Nana Liu,

Mengqin Yu

et al.

Remote Sensing, Journal Year: 2024, Volume and Issue: 16(17), P. 3253 - 3253

Published: Sept. 2, 2024

Sea ice and its surface snow are crucial components of the energy cycle mass balance between atmosphere ocean, serving as sensitive indicators climate change. Observing understanding changes in depth on Antarctic sea essential for research global change studies. This study explores feasibility retrieving using data from Chinese marine satellite HY-2B. Using generic retrieval algorithms, was retrieved HY-2B Scanning Microwave Radiometer (SMR) data, compared with existing products derived other microwave radiometer data. A comparison against ship-based measurements 35th Scientific Expedition shows that SMR Comiso03 algorithm exhibits lowest RMSD, a deviation −1.9 cm to Markus98 Shen22 models. The model agreement GCOM-W1 AMSR-2 product released by National Snow Ice Data Center (NSIDC). Differences two primarily occur during ablation Bellingshausen Sea, Amundsen southern Pacific Ocean. In 2019, monthly average reached maximum January (36.2 cm) decreased minimum May (15.3 cm). Thicker cover observed Weddell Ross seas, due presence multi-year ice, while thinner found Indian Ocean demonstrates high accuracy highlighting potential reliable alternative measurements. significantly contributes observing relationship

Language: Английский

Citations

0
Chlorophyll Production in the Amundsen Sea Boosts Heat Flux to Atmosphere and Weakens Heat Flux to Ice Shelves DOI Creative Commons
Andrew G Twelves, Daniel Goldberg, Paul R. Holland

et al.

Journal of Geophysical Research Oceans, Journal Year: 2024, Volume and Issue: 129(9)

Published: Sept. 1, 2024

Abstract The Amundsen Sea in West Antarctica features rapidly thinning ice shelves, large polynyas, and sizable spring phytoplankton blooms. Although considerable effort has gone into characterizing heat fluxes between the Sea, its associated overlying atmosphere, effect of blooms on distribution remains poorly understood. In this modeling study, we implement a feedback from biogeochemistry onto physics MITgcm‐BLING use it to show that high levels chlorophyll—concentrated Polynya Pine Island Polynya—have potential increase springtime surface warming polynyas by steepening attenuation profile solar radiation with depth. chlorophyll‐associated warm anomaly (on average +0.2C +0.3C) at is quickly dissipated increases longwave, latent sensible loss open water areas. Outside coastal summertime leads an sea 1.7 cm across region, stimulates up 20% additional seasonal melting near fronts shelves. accompanying cold anomaly, caused shading deeper waters, persists year‐round affects decrease volume Circumpolar Deep Water continental shelf. This cooling ultimately thickening 3.5 and, together changes circulation, reduces basal shelves approximately 7% relative model scenario no bloom.

Language: Английский

Citations

0
Antarctic ice-shelf meltwater outflows in satellite radar imagery: ground-truthing and basal channel observations DOI Creative Commons
Jakob Stanley Hamann, Thomas Arney, James D. Kirkham

et al.

Journal of Glaciology, Journal Year: 2024, Volume and Issue: unknown, P. 1 - 13

Published: Oct. 14, 2024

Abstract Ice shelves regulate the flow of Antarctic ice sheet toward ocean and its contribution to sea-level rise. Accurately monitoring basal surface melting is therefore essential for predicting sheet's response climatic warming. In this study, we utilize Sentinel-1A synthetic aperture radar satellite imagery combined with shipboard measurements water temperature salinity investigate presence surficial meltwater plumes along coastline. Our approach reveals a strong correlation between areas pronounced low backscatter extending from significant decreases in salinity, suggesting meltwater-enriched waters. We propose that signature outflows caused by stable stratification upper column, driven density contrasts buoyant, low-salinity current shear reduce Bragg scattering waves. The resulting smooth surfaces were observed adjacent expression deep channels, documented helicopter survey part Bellingshausen Sea edge. present high-temporal resolution as tool identifying release beneath shelves, capable all-weather, day-and-night imaging.

Language: Английский

Citations

0