Basically, they have put a prognostic model for melt ponds into the CICE model (the most sophisticated of
the sea ice models used in climate models).
Not exact matches
This gives confidence in the predictions of the current generation of
ice - sheet
models which are
used to forecast future
ice loss from Antarctica and resulting
sea - level rise.»
The military
uses the microwave information to detect ocean wind speeds to feed into weather
models, among other
uses, but the data happen to be nearly perfect for sensing
sea ice, says Walt Meier, a
sea -
ice specialist with the NSIDC.
«A clear understanding of energy
use and energy storage will help improve
models of how bears will respond to future changes in the
sea ice.»
Dr James Screen from the University of Exeter
used a computer
model to investigate how the dramatic retreat of Arctic
sea ice influences the European summer climate.
«In our study we
used satellite data for
sea ice and
sea surface temperatures to run some coordinated hindcast experiments with five different atmospheric
models,» Ogawa says.
In the study, the researchers
use an
ice - ocean
model created in Bremerhaven to decode the oceanographic and physical processes that could lead to an irreversible inflow of warm water under the
ice shelf — a development that has already been observed in the Amundsen
Sea.
Using the sophisticated UK Met Office climate
model, Dr Screen conducted computer experiments to study the effects of Arctic
sea -
ice loss on the NAO and on Northern European winter temperatures.
The researchers then
used a computer
model of Earth that simulated growth in the Antarctic
ice sheet to see what geophysical impacts this would have aside from generally lowering the
sea level.
Bed topography data are vital for computer
models used to project future changes to
ice sheets and their contribution to
sea level rise.
The team
used a worldwide climate
model that incorporated normal month - to - month variations in
sea surface temperatures and
sea ice coverage, among other climate factors, to simulate 12,000 years» worth of weather.
The data that Old Weather volunteer citizen scientists meticulously transcribe from the logbooks are
used to drive climate and
sea ice models to help understand changes and improve predictions.
Simulations
using a climate
model showed that several large, closely spaced eruptions could have cooled the Northern Hemisphere enough to spark
sea -
ice growth and the subsequent feedback loop.
Kuhn, from Germany's Alfred Wegener Institute, added, «This gives confidence in the predictions of the current generation of
ice sheet
models which are
used to forecast future
ice loss from Antarctica and resulting
sea - level rise.»
The remote impacts of Arctic
sea -
ice loss can only be properly represented
using models that simulate interactions among the ocean,
sea ice, land and atmosphere.
Computational
models that simulate the climate such as CAM5, which is the atmosphere component of the Community Earth System
Model used in the Intergovernmental Panel on Climate Change 5th Assessment, are
used to predict future climate changes, such as the Arctic
sea ice loss.
A number of recent studies linking changes in the North Atlantic ocean circulation to
sea ice extent led Yeager to think that it would also be possible to make decadal predictions for Arctic winter
sea ice cover
using the NCAR - based Community Earth System
Model...
Previously, Kelly was a Postdoctoral Fellow and Research Associate at the University of Washington and the University of Victoria in British Columbia, Canada where she studied the role of the changing Arctic
sea ice cover on global circulation, weather, and climate
using a hierarchy of numerical global climate
models.
Studies of the Arctic system, connections between atmosphere and
sea ice, and between the Arctic and the global system
using remote sensing, conventional measurements, and output from global climate
models.
Finnish Meteorological Institute has been doing estimates of two essential
sea ice parameters — namely, sea ice concentration (SIC) and sea ice thickness (SIT)-- for the Bohai Sea using a combination of a thermodynamic sea ice model and Earth observation (EO) data from synthetic aperture radar (SAR) and microwave radiomet
sea ice parameters — namely,
sea ice concentration (SIC) and sea ice thickness (SIT)-- for the Bohai Sea using a combination of a thermodynamic sea ice model and Earth observation (EO) data from synthetic aperture radar (SAR) and microwave radiomet
sea ice concentration (SIC) and
sea ice thickness (SIT)-- for the Bohai Sea using a combination of a thermodynamic sea ice model and Earth observation (EO) data from synthetic aperture radar (SAR) and microwave radiomet
sea ice thickness (SIT)-- for the Bohai
Sea using a combination of a thermodynamic sea ice model and Earth observation (EO) data from synthetic aperture radar (SAR) and microwave radiomet
Sea using a combination of a thermodynamic
sea ice model and Earth observation (EO) data from synthetic aperture radar (SAR) and microwave radiomet
sea ice model and Earth observation (EO) data from synthetic aperture radar (SAR) and microwave radiometer.
The new findings stem from an analysis that links a widely -
used framework for projecting how
sea level around the world will respond to climate change to a
model that accounts for recently identified processes contributing to Antarctic
ice loss.
In his paper, he proposed a few theories as to what might have gone wrong, including the idea that the
ice age
model he
used was inaccurate or that the estimations of 20th - century
sea - level rise were too high.
If we had done a simple back - of - the - envelope estimate, surely someone would have criticized us for not
using a climate
model... Besides we also looked into regional patterns and the
sea -
ice response in our paper, something one can not do without a climate
model.
I'm not arguing that Tietsche is wrong vis a vis «tipping points» — I'm arguing that climate * is * driving
sea ice loss and that the
model Tietsche
used lacked the proper mechanisms to reliably extrapolate forwards.
This is in contrast to fully - coupled
models, such as those
used in the IPCC projections, which make their own version of the weather and can only be expected to approximate the mean and general patterns of variability and the long - term trajectory of the
sea ice evolution.
Given that impacts don't scale linearly — that's true both because of the statistics of normal distributions, which imply that (damaging) extremes become much more frequent with small shifts in the mean, and because significant breakpoints such as melting points for
sea ice, wet - bulb temperatures too high for human survival, and heat tolerance for the most significant human food crops are all «in play» — the
model forecasts
using reasonable emissions inputs ought to be more than enough for anyone
using sensible risk analysis to know that we making very bad choices right now.
With error bars provided, we can
use the PIOMAS
ice volume time series as a proxy record for reality and compare it against
sea -
ice simulations in global climate
models.
This provides another tool in addition to more directly observed properties for the improvement and evaluation of these
models and is in our view the best
use of PIOMAS in the context of predicting the long - term trajectory of
sea ice.
Mike's work, like that of previous award winners, is diverse, and includes pioneering and highly cited work in time series analysis (an elegant
use of Thomson's multitaper spectral analysis approach to detect spatiotemporal oscillations in the climate record and methods for smoothing temporal data), decadal climate variability (the term «Atlantic Multidecadal Oscillation» or «AMO» was coined by Mike in an interview with Science's Richard Kerr about a paper he had published with Tom Delworth of GFDL showing evidence in both climate
model simulations and observational data for a 50 - 70 year oscillation in the climate system; significantly Mike also published work with Kerry Emanuel in 2006 showing that the AMO concept has been overstated as regards its role in 20th century tropical Atlantic SST changes, a finding recently reaffirmed by a study published in Nature), in showing how changes in radiative forcing from volcanoes can affect ENSO, in examining the role of solar variations in explaining the pattern of the Medieval Climate Anomaly and Little
Ice Age, the relationship between the climate changes of past centuries and phenomena such as Atlantic tropical cyclones and global
sea level, and even a bit of work in atmospheric chemistry (an analysis of beryllium - 7 measurements).
But many of the key questions — regional variability, changes in the patterns of rainfall or statistics of drought, or the interplay of dynamics and thermodynamics in
sea ice change — can only be approached
using comprehensive
models.
It is argued that uncertainty, differences and errors in
sea ice model forcing sets complicate the
use of
models to determine the exact causes of the recently reported decline in Arctic
sea ice thickness, but help in the determination of robust features if the
models are tuned appropriately against observations.
Here are some possible choices — in order of increasing sophistication: * All (or most) scientists agree (the principal Gore argument) * The 20th century is the warmest in 1000 years (the «hockeystick» argument) * Glaciers are melting,
sea ice is shrinking, polar bears are in danger, etc * Correlation — both CO2 and temperature are increasing * Sea levels are rising * Models using both natural and human forcing accurately reproduce the detailed behavior of 20th century global temperature * Modeled and observed PATTERNS of temperature trends («fingerprints») of the past 30 years ag
sea ice is shrinking, polar bears are in danger, etc * Correlation — both CO2 and temperature are increasing *
Sea levels are rising * Models using both natural and human forcing accurately reproduce the detailed behavior of 20th century global temperature * Modeled and observed PATTERNS of temperature trends («fingerprints») of the past 30 years ag
Sea levels are rising *
Models using both natural and human forcing accurately reproduce the detailed behavior of 20th century global temperature *
Modeled and observed PATTERNS of temperature trends («fingerprints») of the past 30 years agree
Using comprehensive data sets of observations made between 1979 and 2001 of
sea ice thickness, draft, extent, and speeds, we find that it is possible to tune
model parameters to give satisfactory agreement with observed data, thereby highlighting the skill of modern
sea ice models, though the parameter values chosen differ according to the
model forcing
used.
In a more recent paper, our own Stefan Rahmstorf
used a simple regression
model to suggest that
sea level rise (SLR) could reach 0.5 to 1.4 meters above 1990 levels by 2100, but this did not consider individual processes like dynamic
ice sheet changes, being only based on how global
sea level has been linked to global warming over the past 120 years.
The paper
uses evidence and
modeling to explain how the sun - blocking impact from a 50 - year stretch of unusually intense eruptions of four tropical volcanoes caused sufficient cooling to produce a long - lasting shift in the generation and migration of Arctic Ocean
sea ice, with substantial consequences for the Northern Hemisphere climate that lasted centuries and left a deep imprint on European history.
[Andy Revkin — The
model runs
used by the U.S. Geological Survey's Steven Amstrup to project
sea ice conditions midcentury onward all presumed carbon dioxide concentrations continue to rise.
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.
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.
They
used the very advanced ECMWF seasonal prediction
model at high resolution and prescribed various
sea -
ice concentrations, ENSO states, as well SST and solar forcings.
Arbetter, 4.7, Statistical A statistical
model using regional observations of
sea ice area and global NCEP air temperature,
sea level pressure, and freezing degree day estimates continues the trend of projecting below - average summer
sea ice conditions for the Arctic.
This month's report includes details on the causes of the 2012 minimum, the
use of
sea ice volume versus extent,
sea ice in climate
models, and late spring 2013 conditions.
Klazes (Public), 3.6 (95 % confidence interval of + / - 0.9), Statistical September extent is predicted
using an estimated minimum value of the PIOMAS arctic
sea ice volume and a simple
model for volume - extent relationship.
After all, the computer
models used to predict a dire future for polar bears combined the Chukchi
Sea with the Southern Beaufort, as having similar
ice habitats («
ice ecoregions»).
We quantify
sea - level commitment in the baseline case by building on Levermann et al. (10), who
used physical simulations to
model the SLR within a 2,000 - y envelope as the sum of the contributions of (i) ocean thermal expansion, based on six coupled climate
models; (ii) mountain glacier and
ice cap melting, based on surface mass balance and simplified
ice dynamic
models; (iii) Greenland
ice sheet decay, based on a coupled regional climate
model and
ice sheet dynamic
model; and (iv) Antarctic
ice sheet decay, based on a continental - scale
model parameterizing grounding line
ice flux in relation to temperature.
A new international study is the first to
use a high - resolution, large - scale computer
model to estimate how much
ice the West Antarctic Ice Sheet could lose over the next couple of centuries, and how much that could add to sea - level ri
ice the West Antarctic
Ice Sheet could lose over the next couple of centuries, and how much that could add to sea - level ri
Ice Sheet could lose over the next couple of centuries, and how much that could add to
sea - level rise.
To assess these implications, we translate global into local SLR projections
using a
model of spatial variation in
sea - level contributions caused by isostatic deformation and changes in gravity as the Greenland and Antarctic
ice sheets lose mass (36 ⇓ — 38), represented as two global 0.5 ° matrices of scalar adjustment factors to the
ice sheets» respective median global contributions to SLR and (squared) to their variances.
Corrigendum to «
Using records from submarine, aircraft and satellites to evaluate climate
model simulations of Arctic
sea ice thickness» published in The Cryosphere, 8, 1839 - 1854, 2014.
Using a global climate
model coupled with an ocean and a
sea -
ice model, we compare the effects of doubling CO2 and halving CO2 on
sea -
ice cover and connections with the atmosphere and ocean.
The current operational ensemble forecast systems
model sea ice dynamically
using the LIM2
model within NEMO ocean
model to represent the dynamic and thermodynamic evolution of
sea ice within the coupled forecast system.
«The
use of a coupled ocean — atmosphere —
sea ice model to hindcast (i.e., historical forecast) recent climate variability is described and illustrated for the cases of the 1976/77 and 1998/99 climate shift events in the Pacific.