Detection of Melt Ponds on Arctic Sea Ice with Optical Satellite Data

Detection of Melt Ponds on Arctic Sea Ice with Optical Satellite Data
Author: Anja Rösel
Publisher: Springer Science & Business Media
Total Pages: 120
Release: 2013-05-23
Genre: Law
ISBN: 3642370330

The Arctic sea ice is characterized by profound changes caused by surface melting processes and the formation of melt ponds in summer. Melt ponds contribute to the ice-albedo feedback as they reduce the surface albedo of sea ice, and hence accelerate the decay of Arctic sea ice. To quantify the melting of the entire Arctic sea ice, satellite based observations are necessary. Due to different spectral properties of snow, ice, and water, theoretically, multi-spectral optical sensors are necessary for the analysis of these distinct surface types. This study demonstrates the potential of optical sensors to detect melt ponds on Arctic sea ice. For the first time, an Arctic-wide, multi-annual melt pond data set for the years 2000-2011 has been created and analyzed.

Melt Ponds on Arctic Summer Sea Ice from Optical Satellite Data

Melt Ponds on Arctic Summer Sea Ice from Optical Satellite Data
Author: Hannah Niehaus
Publisher:
Total Pages: 0
Release: 2024
Genre:
ISBN:

The presence of melt ponds on Arctic summer sea ice strongly alters the absorption of solar radiation by the sea ice-ocean system and thereby the Arctic energy budget. Therefore, melt ponds are key to the positive sea ice-albedo feedback, which is one of the main drivers of the amplified Arctic warming observed in recent decades, and even affects the global climate. To analyze the mechanisms of melt pond evolution and their implications on the sea ice state, and to improve their representation in climate models, comprehensive observational data are needed. This dissertation presents a new approach to retrieve melt pond, sea ice and open ocean fractions at pan-Arctic scales from Sentinel-3 optical satellite data. The newly developed Melt Pond Detection 2 (MPD2) algorithm is the first fully physical retrieval that can distinguish these three surface types at the spatial resolution of 1.2 km. Because multiple combinations of surface type fractions result in similar observations at this coarse resolution, prior information are required for retrieval. As part of the development process, a reference data set of 33 local melt pond fraction maps with a spatial resolution of 10 m has been created from Sentinel-2 satellite data. Parts of these data were then used to calibrate an empirical pre-retrieval to provide preliminary estimates of surface type fractions. In addition, the correlation between sea ice optical properties and air temperature history has been investigated using measurement data from field campaigns. This correlation and the results of the pre-retrieval are used to initialize and constrain the physical retrieval. The results are validated against the full extent of the reference data set, leading to an uncertainty estimate of 7.8 % and 9 % for the melt pond and open ocean fractions, respectively. The MPD2 algorithm has been applied to seven years of Sentinel-3 observations from 2017 to 2023. This data set can be continued for future years and expanded by the application to previous satellite sensors. Finally, the newly produced data set has been used to study regional differences in melt pond evolution: the lowest melt pond fractions are found in the Central Arctic with low seasonal variability, and the highest fractions are observed in the landfast ice-dominated Canadian Archipelago; the highest seasonal and interannual variability are observed in the Beaufort Sea. Additionally, a pan-Arctic analysis correlating the melt pond fraction product with sea ice surface roughness data has been carried out: this showed that flat sea ice features higher melt pond fractions at the beginning of the melt season, while later in the season melt pond fractions tend to be higher on deformed sea ice.

Polar Environments and Global Change

Polar Environments and Global Change
Author: Roger G. Barry
Publisher: Cambridge University Press
Total Pages: 445
Release: 2018-08-09
Genre: History
ISBN: 1108423167

Surveys atmospheric, oceanic and cryospheric processes, present and past conditions, and changes in polar environments.

Estimating Arctic Sea Ice Melt Pond Fraction and Assessing Ice Type Separability During Advanced Melt

Estimating Arctic Sea Ice Melt Pond Fraction and Assessing Ice Type Separability During Advanced Melt
Author: Sasha Nasonova
Publisher:
Total Pages:
Release: 2018
Genre:
ISBN:

Arctic sea ice is rapidly declining in extent, thickness, volume and age, with the majority of the decline in extent observed at the end of the melt season. Advanced melt is a thermodynamic regime and is characterized by the formation of melt ponds on the sea ice surface, which have a lower surface albedo (0.2-0.4) than the surrounding ice (0.5-0.7) allowing more shortwave radiation to enter the system. The loss of multiyear ice (MYI) may have a profound impact on the energy balance of the system because melt ponds on first-year ice (FYI) comprise up to 70% of the ice surface during advanced melt, compared to 40% on MYI. Despite the importance of advanced melt to the ocean-sea ice-atmosphere system, advanced melt and the extent to which winter conditions influence it remain poorly understood due to the highly dynamic nature of melt pond formation and evolution, and a lack of reliable observations during this time. In order to establish quantitative links between winter and subsequent advanced melt conditions, and assess the effects of scale and choice of aggregation features on the relationships, three data aggregation approaches at varied spatial scales were used to compare high resolution satellite GeoEye-1 optical images of melt pond covered sea ice to winter airborne laser scanner surface roughness and electromagnetic induction sea ice thickness measurements. The findings indicate that winter sea ice thickness has a strong association with melt pond fraction (fp) for FYI and MYI. FYI winter surface roughness is correlated with fp, whereas for MYI no association with fp was found. Satellite-borne synthetic aperture radar (SAR) data are heavily relied upon for sea ice observation; however, during advanced melt the reliability of observations is reduced. In preparation for the upcoming launch of the RADARSAT Constellation Mission (RCM), the Kolmogorov-Smirnov (KS) statistical test was used to assess the ability of simulated RCM parameters and grey level co-occurrence matrix (GLCM) derived texture features to discriminate between major ice types during winter and advanced melt, with a focus on advanced melt. RCM parameters with highest discrimination ability in conjunction with optimal GLCM texture features were used as input parameters for Support Vector Machine (SVM) supervised classifications. The results indicate that steep incidence angle RCM parameters show promise for distinguishing between FYI and MYI during advanced melt with an overall classification accuracy of 77.06%. The addition of GLCM texture parameters improved accuracy to 85.91%. This thesis provides valuable contributions to the growing body of literature on fp parameterization and SAR ice type discrimination during advanced melt.

Sea Ice Analysis and Forecasting

Sea Ice Analysis and Forecasting
Author: Tom Carrieres
Publisher: Cambridge University Press
Total Pages: 263
Release: 2017-10-05
Genre: Science
ISBN: 1108417426

A comprehensive overview of the science involved in automated prediction of sea ice, for sea ice analysts, researchers, and professionals.

A Multidimensional Analysis of Sea Ice Melt Pond Properties from Aerial Images

A Multidimensional Analysis of Sea Ice Melt Pond Properties from Aerial Images
Author: Niels Fuchs
Publisher:
Total Pages: 0
Release: 2023
Genre:
ISBN:

Sea ice plays a fundamental role in Polar climate and ecosystems. Melt ponds, forming routinely on Arctic sea ice during summer, can cover and impact a considerable fraction of the ice area. However, data that allow a comprehensive understanding of pond evolution processes remain scarce. Consequently, we cannot yet predict how ponds will develop on the increasingly prevalent young ice in the future. Previous studies have drawn a very heterogeneous picture of pond coverage on young ice, which we can only improve with more detailed measurement data and analysis tools that allow the derivation of properties possibly driving pond evolution. The existence of over ten years of high-resolution aerial image data from AWI aircraft campaigns in the Arctic has motivated me to develop and refine evaluation methods for this dataset, the one-year drift campaign MOSAiC, and future measurement campaigns. I created a customized classification algorithm to classify images into sea ice surface classes with minimal manual intervention. By implementing cutting-edge photogrammetry tools and developing a spatially high-resolution albedo and pond depth retrieval method, I draw an unprecedented multidimensional picture of melt ponds. From this, I derived properties of the sea ice cover that favor and limit pond coverage. I found that within the observed areas, melt pond coverage was more constant than expected, ranging between 15% to 25%. The first-ever tracking of the evolution of the entire pond bathymetry shows that we have so far overlooked the deformability of the pond bottom ice. The multidimensional, high-resolution approach for long-range airborne measurements allowed me to make general recommendations for representative ground measurements. The tools presented, together with the refined insights into pond properties and evolution, will improve our understanding of summer sea ice and can help better assess the role and fate of ponds in the future Polar climate and ecosystems.

Sea Ice

Sea Ice
Author: David N. Thomas
Publisher: John Wiley & Sons
Total Pages: 666
Release: 2017-03-06
Genre: Science
ISBN: 1118778383

Over the past 20 years the study of the frozen Arctic and Southern Oceans and sub-arctic seas has progressed at a remarkable pace. This third edition of Sea Ice gives insight into the very latest understanding of the how sea ice is formed, how we measure (and model) its extent, the biology that lives within and associated with sea ice and the effect of climate change on its distribution. How sea ice influences the oceanography of underlying waters and the influences that sea ice has on humans living in Arctic regions are also discussed. Featuring twelve new chapters, this edition follows two previous editions (2001 and 2010), and the need for this latest update exhibits just how rapidly the science of sea ice is developing. The 27 chapters are written by a team of more than 50 of the worlds’ leading experts in their fields. These combine to make the book the most comprehensive introduction to the physics, chemistry, biology and geology of sea ice that there is. This third edition of Sea Ice will be a key resource for all policy makers, researchers and students who work with the frozen oceans and seas.

The Arctic in the Anthropocene

The Arctic in the Anthropocene
Author: National Research Council
Publisher: National Academies Press
Total Pages: 240
Release: 2014-07-31
Genre: Science
ISBN: 0309301866

Once ice-bound, difficult to access, and largely ignored by the rest of the world, the Arctic is now front and center in the midst of many important questions facing the world today. Our daily weather, what we eat, and coastal flooding are all interconnected with the future of the Arctic. The year 2012 was an astounding year for Arctic change. The summer sea ice volume smashed previous records, losing approximately 75 percent of its value since 1980 and half of its areal coverage. Multiple records were also broken when 97 percent of Greenland's surface experienced melt conditions in 2012, the largest melt extent in the satellite era. Receding ice caps in Arctic Canada are now exposing land surfaces that have been continuously ice covered for more than 40,000 years. What happens in the Arctic has far-reaching implications around the world. Loss of snow and ice exacerbates climate change and is the largest contributor to expected global sea level rise during the next century. Ten percent of the world's fish catches comes from Arctic and sub-Arctic waters. The U.S. Geological Survey estimated that up to 13 percent of the world's remaining oil reserves are in the Arctic. The geologic history of the Arctic may hold vital clues about massive volcanic eruptions and the consequent release of massive amount of coal fly ash that is thought to have caused mass extinctions in the distant past. How will these changes affect the rest of Earth? What research should we invest in to best understand this previously hidden land, manage impacts of change on Arctic communities, and cooperate with researchers from other nations? The Arctic in the Anthropocene reviews research questions previously identified by Arctic researchers, and then highlights the new questions that have emerged in the wake of and expectation of further rapid Arctic change, as well as new capabilities to address them. This report is meant to guide future directions in U.S. Arctic research so that research is targeted on critical scientific and societal questions and conducted as effectively as possible. The Arctic in the Anthropocene identifies both a disciplinary and a cross-cutting research strategy for the next 10 to 20 years, and evaluates infrastructure needs and collaboration opportunities. The climate, biology, and society in the Arctic are changing in rapid, complex, and interactive ways. Understanding the Arctic system has never been more critical; thus, Arctic research has never been more important. This report will be a resource for institutions, funders, policy makers, and students. Written in an engaging style, The Arctic in the Anthropocene paints a picture of one of the last unknown places on this planet, and communicates the excitement and importance of the discoveries and challenges that lie ahead.

Microwave Remote Sensing of Sea Ice

Microwave Remote Sensing of Sea Ice
Author: Frank D. Carsey
Publisher: American Geophysical Union
Total Pages: 466
Release: 1992-04-08
Genre: Science
ISBN: 087590033X

Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 68. Human activities in the polar regions have undergone incredible changes in this century. Among these changes is the revolution that satellites have brought about in obtaining information concerning polar geophysical processes. Satellites have flown for about three decades, and the polar regions have been the subject of their routine surveillance for more than half that time. Our observations of polar regions have evolved from happenstance ship sightings and isolated harbor icing records to routine global records obtained by those satellites. Thanks to such abundant data, we now know a great deal about the ice-covered seas, which constitute about 10% of the Earth's surface. This explosion of information about sea ice has fascinated scientists for some 20 years. We are now at a point of transition in sea ice studies; we are concerned less about ice itself and more about its role in the climate system. This change in emphasis has been the prime stimulus for this book.