Modeling Arctic Melt Ponds Using A Resolved Ice Model With Gcm Forcing
Download Modeling Arctic Melt Ponds Using A Resolved Ice Model With Gcm Forcing full books in PDF, epub, and Kindle. Read online free Modeling Arctic Melt Ponds Using A Resolved Ice Model With Gcm Forcing ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
| Author | : Lee E. Collins |
| Publisher | : |
| Total Pages | : 61 |
| Release | : 2013 |
| Genre | : Albedo |
| ISBN | : |
The albedo of Arctic sea ice depends greatly on the formation of melt ponds. These ponds form in depressions on the ice as surface snow melts during the summer months, and their location is determined mainly by the initial snow topography. Using a high resolution sea ice model forced with data taken from the Atmospheric Radiation Measurement (ARM) site in Barrow, AK, we investigate how specific factors, both internal model parameters and initial conditions, affect the evolution of melt ponds on Arctic sea ice. We also use forcing data taken from output of the Community Earth Systems Model (CESM) to investigate the differences in melt pond parametrization between our model and CESM. The resolved model uses a unique and innovative approach in pond modeling, the "trigger depth" method, to initiate pond drainage. Results from sensitivity analysis on the trigger depth show the validity of this new approach, suggesting it could be useful in other ice models. The initial snowpack has a very large role in pond formation and extent. We use surface topography gathered from LiDAR scans from the ARM site to provide a realistic snowpack surface. For our sensitivity analysis of the total initial amount of snow in the model, we alter only the minimum thickness of the snow on top of the ice, retaining a consistent surface topography for each simulation. The LiDAR topography from the ARM site provides a more realistic approach to the pond model, as opposed to a randomly generated method of creating snow topography. Large initial snowpack inhibits the formation of deep channels in the ice, reducing pond fraction at the end of the melt season. Finally, we force the resolved model simulations with data from CESM and compare the pond behavior to that of CESM. CESM does an unrealistic job of representing melt ponds, partially due to the way melt ponds are parametrized in the model, using a "thickness-class" method for creating and categorizing melt ponds. CESM pond formation occurs over a much broader time span compared to observations and our resolved model. Results from this work will be used to investigate and possibly improve the melt pond parametrization in CESM.
| Author | : |
| Publisher | : |
| Total Pages | : 68 |
| Release | : 2010 |
| Genre | : |
| ISBN | : |
Arctic sea ice is an important component of the global climate system and due to feedback effects the Arctic ice cover is changing rapidly. Predictive mathematical models are of paramount importance for accurate estimates of the future ice trajectory. However, the sea ice components of Global Climate Models (GCMs) vary significantly in their prediction of the future state of Arctic sea ice and have generally underestimated the rate of decline in minimum sea ice extent seen over the past thirty years. One of the contributing factors to this variability is the sensitivity of the sea ice to model physical parameters. A new sea ice model that has the potential to improve sea ice predictions incorporates an anisotropic elastic-decohesive rheology and dynamics solved using the material-point method (MPM), which combines Lagrangian particles for advection with a background grid for gradient computations. We evaluate the variability of the Los Alamos National Laboratory CICE code and the MPM sea ice code for a single year simulation of the Arctic basin using consistent ocean and atmospheric forcing. Sensitivities of ice volume, ice area, ice extent, root mean square (RMS) ice speed, central Arctic ice thickness, and central Arctic ice speed with respect to ten different dynamic and thermodynamic parameters are evaluated both individually and in combination using the Design Analysis Kit for Optimization and Terascale Applications (DAKOTA). We find similar responses for the two codes and some interesting seasonal variability in the strength of the parameters on the solution.
| 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.
| Author | : Intergovernmental Panel on Climate Change (IPCC) |
| Publisher | : Cambridge University Press |
| Total Pages | : 755 |
| Release | : 2022-04-30 |
| Genre | : Science |
| ISBN | : 9781009157971 |
The Intergovernmental Panel on Climate Change (IPCC) is the leading international body for assessing the science related to climate change. It provides policymakers with regular assessments of the scientific basis of human-induced climate change, its impacts and future risks, and options for adaptation and mitigation. This IPCC Special Report on the Ocean and Cryosphere in a Changing Climate is the most comprehensive and up-to-date assessment of the observed and projected changes to the ocean and cryosphere and their associated impacts and risks, with a focus on resilience, risk management response options, and adaptation measures, considering both their potential and limitations. It brings together knowledge on physical and biogeochemical changes, the interplay with ecosystem changes, and the implications for human communities. It serves policymakers, decision makers, stakeholders, and all interested parties with unbiased, up-to-date, policy-relevant information. This title is also available as Open Access on Cambridge Core.
| 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.
| Author | : |
| Publisher | : |
| Total Pages | : 406 |
| Release | : 1999 |
| Genre | : Atmospheric chemistry |
| ISBN | : |
| Author | : Jacqueline Lenoble |
| Publisher | : |
| Total Pages | : 328 |
| Release | : 1985 |
| Genre | : Science |
| ISBN | : |
| Author | : Mohammed Shokr |
| Publisher | : John Wiley & Sons |
| Total Pages | : 628 |
| Release | : 2023-04-20 |
| Genre | : Science |
| ISBN | : 111982821X |
SEA ICE The latest edition of the gold standard in sea ice references In the newly revised second edition of Sea Ice: Physics and Remote Sensing, a team of distinguished researchers delivers an in-depth review of the features and structural properties of ice, as well as the latest advances in geophysical sensors, ice parameter retrieval techniques, and remote sensing data. The book has been updated to reflect the latest scientific developments in macro- and micro-scale sea ice research. For this edition, the authors have included high-quality photographs of thin sections from cores of various ice types, as well as a comprehensive account of all major field expeditions that have systematically surveyed sea ice and its properties. Readers will also find: A thorough introduction to ice physics and physical processes, including ice morphology and age-based structural features Practical discussions of radiometric and radar-scattering observations from sea ice, including radar backscatter and microwave emission The latest techniques for the retrieval of sea ice parameters from space-borne and airborne sensor data New chapters on sea ice thermal microwave emissions and on the impact of climate change on polar sea ice Perfect for academic researchers working on sea ice, the cryosphere, and climatology, Sea Ice: Physics and Remote Sensing will also benefit meteorologists, marine operators, and high-latitude construction engineers.
| Author | : |
| Publisher | : |
| Total Pages | : 40 |
| Release | : 2013 |
| Genre | : |
| ISBN | : |
Arctic sea ice is an important component of the global climate system, reflecting a significant amount of solar radiation, insulating the ocean from the atmosphere and influencing ocean circulation by modifying the salinity of the upper ocean. The thickness and extent of Arctic sea ice have shown a significant decline in recent decades with implications for global climate as well as regional geopolitics. Increasing interest in exploration as well as climate feedback effects make predictive mathematical modeling of sea ice a task of tremendous practical import. Satellite data obtained over the last few decades have provided a wealth of information on sea ice motion and deformation. The data clearly show that ice deformation is focused along narrow linear features and this type of deformation is not well-represented in existing models. To improve sea ice dynamics we have incorporated an anisotropic rheology into the Los Alamos National Laboratory global sea ice model, CICE. Sensitivity analyses were performed using the Design Analysis Kit for Optimization and Terascale Applications (DAKOTA) to determine the impact of material parameters on sea ice response functions. Two material strength parameters that exhibited the most significant impact on responses were further analyzed to evaluate their influence on quantitative comparisons between model output and data. The sensitivity analysis along with ten year model runs indicate that while the anisotropic rheology provides some benefit in velocity predictions, additional improvements are required to make this material model a viable alternative for global sea ice simulations.
| Author | : Peter Lemke |
| Publisher | : Springer Science & Business Media |
| Total Pages | : 473 |
| Release | : 2011-11-22 |
| Genre | : Science |
| ISBN | : 9400720270 |
The Arctic is now experiencing some of the most rapid and severe climate change on earth. Over the next 100 years, climate change is expected to accelerate, contributing to major physical, ecological, social, and economic changes, many of which have already begun. Changes in arctic climate will also affect the rest of the world through increased global warming and rising sea levels. The volume addresses the following major topics: - Research results in observing aspects of the Arctic climate system and its processes across a range of time and space scales - Representation of cryospheric, atmospheric, and oceanic processes in models, including simulation of their interaction with coupled models - Our understanding of the role of the Arctic in the global climate system, its response to large-scale climate variations, and the processes involved.
