In this study, we conduct sensitivity experiments to isolate the role
of sea ice thickness on the atmospheric circulation.
Instead, we are interested in isolating the role
of sea ice thickness on the atmosphere and quantifying its contribution compared to sea ice concentration.
Not exact matches
Researchers from Norway and China have collaborated
on developing an autonomous buoy with instruments that can more precisely measure the optical properties
of Arctic
sea ice while also taking measurements
of ice thickness and temperature.
In addition to the
thickness of the snow cover
on top
of the
sea ice, the buoys also measure the air temperature and air pressure.
From an altitude
of just over 700 km, CryoSat will precisely monitor changes in the
thickness of sea ice and variations in the
thickness of the
ice sheets
on land.
First, we expect the
ice thickness distribution in April 30 from redistribution (divergence / convergence)
of sea ice during December and April, based
on the daily
ice velocity data.
Regarding my # 74:
On sea ice thickness, here is an unreviewed but sensible discussion / analysis
of Arctic
sea ice volume and
thickness as modeled by PIOMAS.
So what we need is detailed topo maps
of the bed and
thickness of the GIS, and to work out a map
of the «net buoyancy», or some such (i.e. total
ice area density subtracted from the area density
of a hypothetical column
of water resting
on the bed and extending up to
sea level).
And you are correct that it depends
on the
thickness of the
ice and the depression below
sea level.
Professor Peter Wadhams, member
of AMEG, expert
on Arctic
sea ice and a reviewer for the IPCC AR5 report, says that the PIOMAS data is based
on actual
thickness measurements.
And variations in the
thickness and extent
of sea ice cloaking the Arctic Ocean are driven by yet another set
of complicating factors, ranging from long - term shifts in atmospheric pressure patterns to events as close - focus as the potent Arctic superstorm I reported
on earlier this month.
Canadian
Ice Service, 4.7, Multiple Methods As with CIS contributions in June 2009, 2010, and 2011, the 2012 forecast was derived using a combination of three methods: 1) a qualitative heuristic method based on observed end - of - winter arctic ice thicknesses and extents, as well as an examination of Surface Air Temperature (SAT), Sea Level Pressure (SLP) and vector wind anomaly patterns and trends; 2) an experimental Optimal Filtering Based (OFB) Model, which uses an optimal linear data filter to extrapolate NSIDC's September Arctic Ice Extent time series into the future; and 3) an experimental Multiple Linear Regression (MLR) prediction system that tests ocean, atmosphere and sea ice predicto
Ice Service, 4.7, Multiple Methods As with CIS contributions in June 2009, 2010, and 2011, the 2012 forecast was derived using a combination
of three methods: 1) a qualitative heuristic method based
on observed end -
of - winter arctic
ice thicknesses and extents, as well as an examination of Surface Air Temperature (SAT), Sea Level Pressure (SLP) and vector wind anomaly patterns and trends; 2) an experimental Optimal Filtering Based (OFB) Model, which uses an optimal linear data filter to extrapolate NSIDC's September Arctic Ice Extent time series into the future; and 3) an experimental Multiple Linear Regression (MLR) prediction system that tests ocean, atmosphere and sea ice predicto
ice thicknesses and extents, as well as an examination
of Surface Air Temperature (SAT),
Sea Level Pressure (SLP) and vector wind anomaly patterns and trends; 2) an experimental Optimal Filtering Based (OFB) Model, which uses an optimal linear data filter to extrapolate NSIDC's September Arctic Ice Extent time series into the future; and 3) an experimental Multiple Linear Regression (MLR) prediction system that tests ocean, atmosphere and sea ice predicto
Sea Level Pressure (SLP) and vector wind anomaly patterns and trends; 2) an experimental Optimal Filtering Based (OFB) Model, which uses an optimal linear data filter to extrapolate NSIDC's September Arctic
Ice Extent time series into the future; and 3) an experimental Multiple Linear Regression (MLR) prediction system that tests ocean, atmosphere and sea ice predicto
Ice Extent time series into the future; and 3) an experimental Multiple Linear Regression (MLR) prediction system that tests ocean, atmosphere and
sea ice predicto
sea ice predicto
ice predictors.
A threshold h applied
on the (
thickness Feb = Mar concentration Sept) field yields the predicted September extent after the regression with the past four years
of sea ice extent observations.
Canadian
Ice Service, 4.7 (+ / - 0.2), Heuristic / Statistical (same as June) The 2015 forecast was derived by considering a combination of methods: 1) a qualitative heuristic method based on observed end - of - winter Arctic ice thickness extents, as well as winter Surface Air Temperature, Sea Level Pressure and vector wind anomaly patterns and trends; 2) a simple statistical method, Optimal Filtering Based Model (OFBM), that uses an optimal linear data filter to extrapolate the September sea ice extent timeseries into the future and 3) a Multiple Linear Regression (MLR) prediction system that tests ocean, atmosphere and sea ice predicto
Ice Service, 4.7 (+ / - 0.2), Heuristic / Statistical (same as June) The 2015 forecast was derived by considering a combination
of methods: 1) a qualitative heuristic method based
on observed end -
of - winter Arctic
ice thickness extents, as well as winter Surface Air Temperature, Sea Level Pressure and vector wind anomaly patterns and trends; 2) a simple statistical method, Optimal Filtering Based Model (OFBM), that uses an optimal linear data filter to extrapolate the September sea ice extent timeseries into the future and 3) a Multiple Linear Regression (MLR) prediction system that tests ocean, atmosphere and sea ice predicto
ice thickness extents, as well as winter Surface Air Temperature,
Sea Level Pressure and vector wind anomaly patterns and trends; 2) a simple statistical method, Optimal Filtering Based Model (OFBM), that uses an optimal linear data filter to extrapolate the September sea ice extent timeseries into the future and 3) a Multiple Linear Regression (MLR) prediction system that tests ocean, atmosphere and sea ice predicto
Sea Level Pressure and vector wind anomaly patterns and trends; 2) a simple statistical method, Optimal Filtering Based Model (OFBM), that uses an optimal linear data filter to extrapolate the September
sea ice extent timeseries into the future and 3) a Multiple Linear Regression (MLR) prediction system that tests ocean, atmosphere and sea ice predicto
sea ice extent timeseries into the future and 3) a Multiple Linear Regression (MLR) prediction system that tests ocean, atmosphere and sea ice predicto
ice extent timeseries into the future and 3) a Multiple Linear Regression (MLR) prediction system that tests ocean, atmosphere and
sea ice predicto
sea ice predicto
ice predictors.
Currently, the NASA IceBridge mission supplies both
sea ice thickness and snow depth measurements in spring, providing timely information
on the state
of the
ice cover as the melt season begins.
Sea ice extent,
thickness and volume are all normal, yet the Flat Earth Society
of climate scientists drones
on endlessly about an
ice - free Arctic — which they will never live to see.
The
thickness of Arctic
sea ice has also been
on a steady decline over the last several decades.
On the text on the extent of Arctic sea ice, the UK asked about changes in Arctic sea ice thickness and the US about summer sea ice extent, to which the CLAs replied that this information is discussed in detail in the underlying assessmen
On the text
on the extent of Arctic sea ice, the UK asked about changes in Arctic sea ice thickness and the US about summer sea ice extent, to which the CLAs replied that this information is discussed in detail in the underlying assessmen
on the extent
of Arctic
sea ice, the UK asked about changes in Arctic
sea ice thickness and the US about summer
sea ice extent, to which the CLAs replied that this information is discussed in detail in the underlying assessment.
A comparison
of the modeled
ice thickness on 1 June 2007, 2008, and 2009, and the initial
ice thickness on 28 May 2010 reveals considerably larger
ice thickness mainly in the East Siberian
Sea, north
of the East Siberian
Sea, and in the vicinity
of the North Pole in 2010 compared to 2007 — 2009.
Peter Wadhams, President
of the International Association
on Sea Ice and Head of the Polar Ocean Physics Group / Department of Applied Mathematics and Theoretical Physics, University of Cambridge, says: «It is quite urgent that we recognize what is going on... the ice has been getting thinner over the last 40 years since I have been measuring it, and it has lost about one - half of its thickness... five years ago the shrinkage started to accelera
Ice and Head
of the Polar Ocean Physics Group / Department
of Applied Mathematics and Theoretical Physics, University
of Cambridge, says: «It is quite urgent that we recognize what is going
on... the
ice has been getting thinner over the last 40 years since I have been measuring it, and it has lost about one - half of its thickness... five years ago the shrinkage started to accelera
ice has been getting thinner over the last 40 years since I have been measuring it, and it has lost about one - half
of its
thickness... five years ago the shrinkage started to accelerate.
It is hypothesized that these delayed responses reflect the dynamical influence
of the AO
on the
thickness of the wintertime
sea ice, whose persistent «footprint» is reflected in the heat fluxes during the subsequent spring, in the extent
of open water during the subsequent summer, and the heat liberated in the freezing
of the open water during the subsequent autumn.»
Reasoning for a decrease in
sea ice extent from recent years, perhaps approaching new record - low minimum, focuses
on the below - normal
sea ice thickness overall, the thinning
of sea ice in coastal
seas, rotting
of old multi-year
sea ice, warm temperatures in April and May 2010, and the rapid loss
of sea ice area seen during May.
Reasoning for a new record minimum focuses
on the below - normal
ice thickness overall, the thinning
of sea ice in coastal
seas, rotting
of old multi-year
sea ice, and the rapid loss
of sea ice area seen during May.
One
of the important ingredients
of the new model is data
on the
thickness of ice floating
on the
sea.
The new
ice thickness estimates will also be used to improve
on - going seasonal predictions
of sea ice extent.
On page 16 here: https://curryja.files.wordpress.com/2014/10/
sea-
ice-physical-processes.pdf There is the «Annual cycle
of net surface heat flux for various
ice thicknesses» Roughly interpolating the no
sea ice flux I got an average
of — 310 Wm2 over the course
of a year.
``... examination
of records
of fast
ice thickness and
ice extent from four Arctic marginal
seas (Kara, Laptev, East Siberian, and Chukchi) indicates that long - term trends are small and generally statistically insignificant, while trends for shorter records are not indicative
of the long - term tendencies due to strong low - frequency variability in these time series, which places a strong limitation
on our ability to resolve long - term trends....
5.3.7 In the Polar Regions, the main effect foreseen is a reduction in
thickness and extent
of glaciers,
ice sheets,
sea ice, and permafrost, and associated impacts
on infrastructures, ecosystems, and traditional ways
of life.
Canadian
Ice Service, 4.7 (± 0.2), Heuristic / Statistical (same as June) The 2015 forecast was derived by considering a combination of methods: 1) a qualitative heuristic method based on observed end - of - winter Arctic ice thickness extents, as well as winter Surface Air Temperature, Sea Level Pressure and vector wind anomaly patterns and trends; 2) a simple statistical method, Optimal Filtering Based Model (OFBM), that uses an optimal linear data filter to extrapolate the September sea ice extent timeseries into the future and 3) a Multiple Linear Regression (MLR) prediction system that tests ocean, atmosphere and sea ice predicto
Ice Service, 4.7 (± 0.2), Heuristic / Statistical (same as June) The 2015 forecast was derived by considering a combination
of methods: 1) a qualitative heuristic method based
on observed end -
of - winter Arctic
ice thickness extents, as well as winter Surface Air Temperature, Sea Level Pressure and vector wind anomaly patterns and trends; 2) a simple statistical method, Optimal Filtering Based Model (OFBM), that uses an optimal linear data filter to extrapolate the September sea ice extent timeseries into the future and 3) a Multiple Linear Regression (MLR) prediction system that tests ocean, atmosphere and sea ice predicto
ice thickness extents, as well as winter Surface Air Temperature,
Sea Level Pressure and vector wind anomaly patterns and trends; 2) a simple statistical method, Optimal Filtering Based Model (OFBM), that uses an optimal linear data filter to extrapolate the September sea ice extent timeseries into the future and 3) a Multiple Linear Regression (MLR) prediction system that tests ocean, atmosphere and sea ice predicto
Sea Level Pressure and vector wind anomaly patterns and trends; 2) a simple statistical method, Optimal Filtering Based Model (OFBM), that uses an optimal linear data filter to extrapolate the September
sea ice extent timeseries into the future and 3) a Multiple Linear Regression (MLR) prediction system that tests ocean, atmosphere and sea ice predicto
sea ice extent timeseries into the future and 3) a Multiple Linear Regression (MLR) prediction system that tests ocean, atmosphere and sea ice predicto
ice extent timeseries into the future and 3) a Multiple Linear Regression (MLR) prediction system that tests ocean, atmosphere and
sea ice predicto
sea ice predicto
ice predictors.
The Outlook also underscored important lessons for improvements in future efforts, including: a need for additional work
on remote sensing
of spring and summer
sea ice conditions;
sea ice thickness data; and more formal forecasting and evaluation methods.
«Impacts
of Assimilating Satellite
Sea Ice Concentration and
Thickness on Arctic
Sea Ice Prediction in the NCEP Climate Forecast System» J. Climate 0, (https://doi.org/10.1175/JCLI-D-17-0093.1).
As noted last month, this range depends in part
on the relative weight that the respondents give to «initial conditions,» e.g., age and
thickness of sea ice at the end
of spring, versus whether summer winds in 2008 will be as supportive for
ice loss as the favorable winds were in 2007.
The findings are based
on satellite readings
of Antarctic
sea ice movement and
thickness, as well as new, detailed interpretations
of charts showing the shape
of the
sea bottom around Antarctica.
So, prompted by reports
of the heaviest
sea ice conditions
on the East Coast «in decades» and news that
ice on the Great Lakes is, for mid-April, the worst it's been since records began, I took a close look at
ice thickness charts for the Arctic.
Since 1950, Arctic
sea ice has lost half its area and half its
thickness, helping to cause the phenomenon
of Arctic amplification − the greater temperature rise (approaching 3 °C) observed in the Arctic than anywhere else
on Earth.
Based
on winter air temperatures and
sea ice extents and
thickness, a September 2016 minimum
ice extent value
of 4.3 million km2 is heuristically predicted.
As with previous CIS contributions, the 2016 forecast was derived by considering a combination
of methods: 1) a qualitative heuristic method based
on observed end -
of - winter Arctic
ice thickness / extent, as well as winter surface air temperature, spring
ice conditions and the summer temperature forecast; 2) a simple statistical method, Optimal Filtering Based Model (OFBM), that uses an optimal linear data filter to extrapolate the September
sea ice extent time - series into the future and 3) a Multiple Linear Regression (MLR) prediction system that tests ocean, atmosphere and
sea ice predictors.
Is it your contention that the
thickness of fast
ice on these
sea shores is the same from year to year?
Submissions
of melt pond fraction,
ice thickness, and any other
sea ice parameter based
on early - season data that could contribute to a status summary
of pre-season conditions and help inform subsequent contributions to the regular SIO monthly report.
From the atmospheric temperature rise to the acidification
of the
sea, from
ice thickness and extent to
sea levels, we really need to continue to know what is going
on.
NOAA@NSIDC is pleased to announce the release
of On -
Ice Arctic
Sea Ice Thickness Measurements by Auger, Core, and Electromagnetic Induction, From the Fram Expedition Onward.
Until then, we have some new observational data
of Canadian
sea ice thickness and this remarkable figure of sea ice volume since 1979 from Neven's Arctic Sea Ice Blog, based on data from the University of Washington's Polar Science Center [click to enlarg
sea ice thickness and this remarkable figure of sea ice volume since 1979 from Neven's Arctic Sea Ice Blog, based on data from the University of Washington's Polar Science Center [click to enlarg
ice thickness and this remarkable figure
of sea ice volume since 1979 from Neven's Arctic Sea Ice Blog, based on data from the University of Washington's Polar Science Center [click to enlarg
sea ice volume since 1979 from Neven's Arctic Sea Ice Blog, based on data from the University of Washington's Polar Science Center [click to enlarg
ice volume since 1979 from Neven's Arctic
Sea Ice Blog, based on data from the University of Washington's Polar Science Center [click to enlarg
Sea Ice Blog, based on data from the University of Washington's Polar Science Center [click to enlarg
Ice Blog, based
on data from the University
of Washington's Polar Science Center [click to enlarge]:
Based
on the last 20 years, the reduction in
sea ice cover and its
thickness have enhanced the warming
of the Arctic throughout the year.
Based
on the understanding
of both the physical processes that control key climate feedbacks (see Section 8.6.3), and also the origin
of inter-model differences in the simulation
of feedbacks (see Section 8.6.2), the following climate characteristics appear to be particularly important: (i) for the water vapour and lapse rate feedbacks, the response
of upper - tropospheric RH and lapse rate to interannual or decadal changes in climate; (ii) for cloud feedbacks, the response
of boundary - layer clouds and anvil clouds to a change in surface or atmospheric conditions and the change in cloud radiative properties associated with a change in extratropical synoptic weather systems; (iii) for snow albedo feedbacks, the relationship between surface air temperature and snow melt over northern land areas during spring and (iv) for
sea ice feedbacks, the simulation
of sea ice thickness.
With regard to proxy studies, same basic questions, are these direct or passive correlations, what evidence that tree ring core
thickness depends only
on temperature (what about precipitation, cloud cover, volcanic activity,
sea surface temperatue changes,
sea current changes, solar irradiance changes, cloud cover, etc.) How are these variables accounted for when analysis
of ice cores is completed, or for that matter when computer models, and / or proxy studies are completed.
Shibata et al. (Kitami Institute
of Technology); 5.4; Heuristic, Statistical Prediction is based
on sea ice thickness, summer melt, outflow, and cloudiness.
Ship - based observations from the NASA Icescape cruise with USCG Healy (Perovich and Polashenski) indicate that the
ice cover in the Chukchi
Sea is in an advanced state
of melt with melt ponds melted through in many areas and
ice thicknesses on the order
of 1m (Figure 3).
Further research is needed particularly
on role
of natural internal variability in influencing
sea ice thickness and extent.