Dynamics of the Coupled Ice-ocean System in the Marginal Ice Zone PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Dynamics of the Coupled Ice-ocean System in the Marginal Ice Zone PDF full book. Access full book title Dynamics of the Coupled Ice-ocean System in the Marginal Ice Zone by Sirpa Häkkinen. Download full books in PDF and EPUB format.
Author: Sirpa Häkkinen
Publisher:
ISBN:
Category : Ocean-atmosphere interaction
Languages : en
Pages : 124
Get Book Here
Book Description
This study is aimed at the modelling of mesoscale processes such as up/downwelling and ice edge eddies in the marginal ice zones. A 2-dimensional coupled ice-ocean model is used for the study. The ice model is coupled to the reduced gravity ocean model (f-plane) through interfacial stresses. The constitutive equations of the sea ice are formulated on the basis of the Reiner-Rivlin theory. The internal ice stresses are important only at high ice concentrations (90-100%), otherwise the ice motion is essentially free drift, where the air-ice stress is balanced by the ice-water stress. The model was tested by studying the upwelling dynamics. Winds parallel to the ice edge with the ice on the right produce upwelling because the air-ice momentum flux is much greater than air-ocean momentum flux, and thus the Ekman transport is bigger under the ice than in the open water. The upwelling simulation was extended to include temporally varying forcing, which was chosen to vary sinusoidally with 4 day period. This forcing resembles successive cyclone passings. In the model with thin oceanic upper layer, ice bands were formed. The up/downwelling signals do not disappear in wind reversals because of nonlinear advection. This leads to convergences and divergences in oceanic and ice velocities which manifest themselves as ice banding. At least one wind reversal is needed to produce one ice band.
Author: Sirpa Häkkinen
Publisher:
ISBN:
Category : Ocean-atmosphere interaction
Languages : en
Pages : 124
Get Book Here
Book Description
This study is aimed at the modelling of mesoscale processes such as up/downwelling and ice edge eddies in the marginal ice zones. A 2-dimensional coupled ice-ocean model is used for the study. The ice model is coupled to the reduced gravity ocean model (f-plane) through interfacial stresses. The constitutive equations of the sea ice are formulated on the basis of the Reiner-Rivlin theory. The internal ice stresses are important only at high ice concentrations (90-100%), otherwise the ice motion is essentially free drift, where the air-ice stress is balanced by the ice-water stress. The model was tested by studying the upwelling dynamics. Winds parallel to the ice edge with the ice on the right produce upwelling because the air-ice momentum flux is much greater than air-ocean momentum flux, and thus the Ekman transport is bigger under the ice than in the open water. The upwelling simulation was extended to include temporally varying forcing, which was chosen to vary sinusoidally with 4 day period. This forcing resembles successive cyclone passings. In the model with thin oceanic upper layer, ice bands were formed. The up/downwelling signals do not disappear in wind reversals because of nonlinear advection. This leads to convergences and divergences in oceanic and ice velocities which manifest themselves as ice banding. At least one wind reversal is needed to produce one ice band.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 3
Get Book Here
Book Description
The recent article by Hakkinen [1987] creatively addresses a number of important dynamic and thermodynamic processes in the marginal ice zone (MIZ). We believe that her study will stimulate further research on the coupled ice-ocean system. For now we would like to offer the following discussion of the need to augment the entrainment equation to include surface buoyancy flux for general application to the MIZ.
Author: S. HAKKINEN
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Author: L.H. Kantha
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Author: Peter Wadhams
Publisher: CRC Press
ISBN: 1482283085
Category : Science
Languages : en
Pages : 364
Get Book Here
Book Description
ICe in the Ocean examines sea ice and icebergs and their role in the global climate system. It is comprehensive textbook suitablefor students, pure and applied researchers, and anyone interested in the polar oceans; the distribution of sea ice; the mechanisms of growth, development and decay; the thermodynamics and dynamics of sea ice; sea ice defo
Author: M. IKEDA
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Glaciology
Languages : en
Pages : 648
Get Book Here
Book Description
Author: Samuel Dale Brenner
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Get Book Here
Book Description
The ongoing loss of Arctic sea ice prompts questions about changes in momentum transfer across the atmosphere-ice-ocean system and potential climate feedback mechanisms, but the role of the ice in mediating that process is not fully understood. To address knowledge gaps about atmosphere-ice-ocean momentum transfer, this study makes use of in situ measurements collected during two recent observational campaigns in the Beaufort Sea: the Marginal Ice Zone (MIZ) program and the Stratified Ocean Dynamics of the Arctic (SODA) program. The research is presented in two parts.Part I develops data processing methods for instrumentation deployed as part of the SODA program while part II uses data from both programs to evaluate controls of sea ice on the ocean surface stress and the associated response in the ocean surface mixed layer (ML). Measurements of upper ocean properties can be challenging in the Arctic Ocean due to environmental conditions, including the need for moored instruments to avoid contact with sea ice. Part I of this work describes methods for developing usable data products from upward-looking Acoustic Doppler Current Profiler (ADCP) measurements on the SODA moorings. This encompasses methods for creating combined data records from vertically-offset ADCPs on the same mooring chain and methods for using ADCPs to estimate surface ML depth and temperature. As ML depth and temperature measurements are not typically possible from subsurface moorings in the Arctic, the approach developed here provides considerable value and could be applied to other extant mooring records to recover information about ML property variability or trends. Building on these measurements, part II considers how sea ice properties, such as concentration and morphology, affect the transfer of momentum from the sea ice to the ocean and the associated upper-ocean dynamics. Ice-ocean drag coefficients, a measure of momentum transfer efficiency, calculated using a force-balance approach from the SODA mooring data show seasonal variations consistent with past observations, but at odds with previous model results.Tests of model parameterizations of drag based on direct observations of under-ice morphology reveal that the model-observation mismatch can be attributed to inaccuracies in empirical translations from bulk geometric properties to detailed geometry statistics, especially under-representation of floe sizes. The mooring measurements further show a seasonal upper-ocean response to surface stress, with minimal energy in ML inertial oscillations under sea ice cover. A simplified momentum budget for the coupled ice-ocean system shows that the seasonality stems from a combination of internal stress in the ice damping the oscillations and seasonal variability in the ocean ML depth. Finally, shipboard measurements from the MIZ program show the evolution of ice-edge-located freshwater front as it reacted to changes in the surface wind stress, raising questions about how sea ice might impact spatial heterogeneity of stress and how that might interact with frontal dynamics. This research shows that boundary layer dynamics and internal ice mechanics both play a role in mediating atmosphere-ice-ocean momentum transfer. The results suggest future trends of more "slippery" ice-ocean boundary layer, and decreasing internal sea ice stress, which could lead to increased sea ice drift speeds and more direct atmosphere-ocean coupling.
Author: Matti Leppaeranta
Publisher:
ISBN:
Category :
Languages : en
Pages : 116
Get Book Here
Book Description
The dynamics of sea ice in the marginal ice zone (MIZ) are considered both from theoretical and from experimental point of view. Ice kinematics measurements were made with the Del Norte microwave trisponder system in MIZEX-83 and MIZEX-84 Greenland Sea experiments. Differential ice motion was measured with four to six stations on the ice in the scale of 2-20 km at three minute intervals. On several occasions a rapid slip occurred in measured distances. Ice velocity fluctuations were typically of the order of 1 cm/s and large deformation rates a few per cent hour. Various spectra of differential ice drift showed a moderate inertial peak and a red noise character at higher frequencies, up to about half-hour period. The maximum rate of shear was about twice as large as divergence from 12-h to about 2-h period. Analysis of current measurements beneath the drifting ice show that current variations show up highly damped in the ice. In differential motion, ice-current coherence was significant only at low frequencies (lower than one cycle per day).
Author: Matti Leppäranta
Publisher: Springer Science & Business Media
ISBN: 3540269703
Category : Science
Languages : en
Pages : 282
Get Book Here
Book Description
This book presents the fundamental laws of sea ice drift, as derived from the material properties of sea ice, the basic laws of mechanics, and the latest modeling techniques. Topics covered include the science of sea ice drift, forecasting velocity based on volume, size and shape, sea ice ridging and remote sensing, modelling of ice conditions, and the role of sea ice drift in oceanography, marine ecology and engineering.
