Not exact matches
A new University of Washington study, with funding and satellite
data from NASA and other agencies, finds a
trend toward earlier sea
ice melt in the spring and later
ice growth in the fall across all 19 polar bear populations, which can negatively impact the feeding and breeding capabilities of the bears.
«These assessments of
ice shelves need to be done regularly» to build up a time series of
data — and ultimately to be able to separate a
trend signal from the noise.
Scientists at the National Snow and
Ice Data Center (NSIDC), University College London, University of New Hampshire and University of Washington analyzed 300 summer Arctic sea ice forecasts from 2008 to 2013 and found that forecasts are quite accurate when sea ice conditions are close to the downward trend that has been observed in Arctic sea ice for the last 30 yea
Ice Data Center (NSIDC), University College London, University of New Hampshire and University of Washington analyzed 300 summer Arctic sea
ice forecasts from 2008 to 2013 and found that forecasts are quite accurate when sea ice conditions are close to the downward trend that has been observed in Arctic sea ice for the last 30 yea
ice forecasts from 2008 to 2013 and found that forecasts are quite accurate when sea
ice conditions are close to the downward trend that has been observed in Arctic sea ice for the last 30 yea
ice conditions are close to the downward
trend that has been observed in Arctic sea
ice for the last 30 yea
ice for the last 30 years.
The
trends revealed by the
data were clear: The average albedo in the northern area of the Arctic Ocean, including open water and sea
ice, is declining in all summer months (May - August).
Now the
trend may be going in the other direction with new
data about
ice sheets, although a lot more research is needed, he said.
To project that
trend forward, the team then used models recently developed to analyze Antarctic
ice sheet collapse, plus large global
data sets to tailor specific Atlantic tropical cyclone
data and create «synthetic» storms to simulate future weather patterns.
Comiso and other climate scientists reject the suggestion that his
data set may overestimate the recent
trend in Antarctic sea -
ice growth — by as much as two - thirds, according to Eisenman's analysis.
The authors of a new study reviewing the volume
data, detailed on Monday in the journal Nature Geoscience, are quick to caution, though, that one single year of rebound doesn't suggest any sea
ice recovery, as the overall
trend is still downward.
first, given all the talk on that «michael's graph» thread, i have to laugh at the fact that all those
trend lines are drawn starting at 1998... [do we have any «proxy
data» from which to infer attitudes going back to the little
ice age?
BPL: The warming
trend is not twenty years old, but 165 years old by direct measurements and perhaps 250 years old if you include
ice - core
data.
Further signs of this warming
trend can be seen in the Northern Hemisphere Sea
Ice Extent from the National Snow and
Ice Data Center.
Still, the scientists, at the National Snow and
Ice Data Center in Boulder, Colo., said that the extent of the ice in the Arctic this summer was 33 percent smaller than the average extent tracked since satellites started monitoring the region in 1979, and that the long - term trend is toward an ice - free summer in the Arctic Ocean within a few decad
Ice Data Center in Boulder, Colo., said that the extent of the
ice in the Arctic this summer was 33 percent smaller than the average extent tracked since satellites started monitoring the region in 1979, and that the long - term trend is toward an ice - free summer in the Arctic Ocean within a few decad
ice in the Arctic this summer was 33 percent smaller than the average extent tracked since satellites started monitoring the region in 1979, and that the long - term
trend is toward an
ice - free summer in the Arctic Ocean within a few decad
ice - free summer in the Arctic Ocean within a few decades.
The same issues have dogged other attempts by climate scientists to glean clues on climate
trends from bodies of
data collected by satellites and weather balloons for other reasons (not to mention ongoing attempts to discern climate patterns in tree rings,
ice layers, and other natural substitutes for thermometers; remember the «hockey stick» debate?).
Still not sure if their method is the best way to visualize this
ice - out
data, but I like that you can see the
trends of many lakes at once.
Clearly, the sea
ice volume
data plot is the single most important topic of discussion, yet in the article it is shown in Figure 1 with a poor vertical scale and amongst linear
trend lines which mislead and make the curve appear to be linear and reach the zero point far out in the future.
If you plot the average Arctic Sea
Ice extent for 20 years, the you should also plot the monthly maximum and minimum values on the same figure so that we can get some perspective on where the 2007 and 2008
data falls in the context of annual variability, or examine for
trends.
The next implication is that those who try to predict
ice volume using past
ice volume
data are largely picking up the artifical
trend that is built into the
data.
The horror story is not what the scientists present as
data, but what the media make of a (too) short
trend, including the complete melting of the Greenland
ice sheet.
Comiso and other climate scientists reject the suggestion that his
data set may overestimate the recent
trend in Antarctic sea -
ice growth — by as much as two - thirds, according to Eisenman's analysis.
Updated, July 23, 1:40 p.m. A new study of methods used to track Antarctic sea
ice trends has raised important questions about whether recent increases in
ice there are, to a significant extent, an illusion created by flawed analysis of
data collected by a series of satellites.
Another NASA sea -
ice data set, processed using the other standard algorithm, shows a growth
trend similar to that in Comiso's current
data.
The overall global glacier mass balance
trend is shown on the National Snow and
Ice Data Center (NDIS) graph here.
Figure 3: National Snow and
Ice Data Center (NSIDC) Antarctic, Arctic, and global (sum of the two) sea ice extents with linear tren
Ice Data Center (NSIDC) Antarctic, Arctic, and global (sum of the two) sea
ice extents with linear tren
ice extents with linear
trends.
Study of Greenland
ice provides a 2500 year perspective indicating we headed into a mini-
ice-age as happened from the mid 1300's to the mid 1800's; and the
data from the 1200 or so floating buoys around the world's oceans are likewise showing a cooling
trend, and have been for some time.
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
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 predictors.
The application of
trends to climate
data began in the 1970s with the prediction of a coming
ice age as temperatures declined from 1940.
Thus, the
data indicate a continued
trend towards flushing of old multiyear
ice out of Canadian Basin into the Beaufort and Chukchi Seas.
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
ice extent timeseries into the future and 3) a Multiple Linear Regression (MLR) prediction system that tests ocean, atmosphere and sea
ice predicto
ice predictors.
People observed this
trend of earlier
ice - out dates by comparing to their own recollections, and all one has to do is look at the aggregated
data which has been collected over the years.
Our recently published Nature paper (King et al, 2012), used GRACE gravity
data to infer Antarctic
ice mass
trends as in previous work, but with an updated estimate of the GIA correction.
The antarctic
ice winter max decreased by about one third during this period, and the HadCRUT temp
data base for that region during that period does show a substantial surface air temperature warming
trend.
«To summarize - Using the 60 and 1000 year quasi repetitive patterns in conjunction with the solar
data leads straightforwardly to the following reasonable predictions for Global SSTs 1 Continued modest cooling until a more significant temperature drop at about 2016 - 17 2 Possible unusual cold snap 2021 - 22 3 Built in cooling
trend until at least 2024 4 Temperature Hadsst3 moving average anomaly 2035 — 0.15 5Temperature Hadsst3 moving average anomaly 2100 — 0.5 6 General Conclusion — by 2100 all the 20th century temperature rise will have been reversed, 7 By 2650 earth could possibly be back to the depths of the little
ice age.
More importantly, we must wonder what the satellites would have observed happening in the Antarctic when Roald Amundsen sailed through the Arctic in 1903 - 1905 on the small wooden ship Gjøa when the Northwest Passage was open to sailing vessels, and again in 1940 - 42 and 1944 (St. Roch), it is possible the reduction in Arctic
ice is not an indicator of warming, since it was balanced by record high Antarctic
ice levels and a rising
trend line for the
data set since 1979.
The only thing that maybe correct in the analysis is the oscillation, because the warming
trend from the mini
ice age is in the
data too.
When sceptics look at statistical
data, whether it is recent
ice melt, deep sea temperatures, current
trend in global surface temperatures, troposphere temperatures,
ice core records etc. they look at the
data as it is without any pre-conceptions and describe what it says.
Independent non-thermometer
data (so - called proxies, like tree rings,
ice cores, ocean sediments, stalagmites, etc.) also show no warming
trend between 1978 and 2000.
Also, the Greenland
ice core
data do agree pretty good with sulfate emissions estimates, but Greenland is located downwind of the US and Canada and does not represent global
trends impacted by developing countries.
Figure 3 (
Data sources here and here) There is a secular warming
trend that has persisted since the end of the Little
Ice Age in the 19th century.
However, currently both modern and paleo
data - model intercomparisons display large differences in sea -
ice extent and
trends.
Updating this analysis using observational
data through 2011 (not even including the 2012 record low sea
ice extent), the 32 - year
trend (1979 - 2011) is -530 thousand square km per decade, and the 20 - year
trend is -700 thousand square km per decade.
The study found it had almost enough
data to conclude Antarctica's
ice sheets are melting as part of an increasing
trend with a «reasonable level of confidence.
Decadal
trends also differ greatly between POLES and TOVS primarily owing to the discontinuation of
ice station
data in the POLES dataset after 1991.
Since current
ice melt
data could indicate variable climate
trends and aren't necessarily part of an accelerating
trend, the study warned that predictions of future sea - level rise should not be based on measurements of glacial loss» Daily Mail.
Yet if we look at the earlier
data as well, it just shows an overall warming
trend (natural) from the 1650's from a period known as a «little
ice age».
ie, a look at the actual temperature in the central england
data set from the 1600's, would give a null hypothesis for any significant observable human AGW signature (ie a low % of AGW) as there only appear to be a gradual warming
trend from a period known as the «little
ice age».
[3] An implementation of the diff - of - gaussian filter is presented here: https://climategrog.wordpress.com/2016/09/18/diff-of-gaussian-filter/ [4] The sea -
ice area
data used in the decadal
trend analysis are provided by Cryosphere Today team at U. Illinois.
This is an important article, Climategrog, because it shows from a different type of
data (date of minimum extent) that something happened around 2007 to Arctic sea
ice that interrupted a 35 year
trend.
Canadian
Ice Service; 5.0; Statistical As with Canadian Ice Service (CIS) contributions in June 2009 and June 2010, the 2011 forecast was derived using a combination of three methods: 1) a qualitative heuristic method based on observed end - of - winter Arctic Multi-Year Ice (MYI) 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; 5.0; Statistical As with Canadian
Ice Service (CIS) contributions in June 2009 and June 2010, the 2011 forecast was derived using a combination of three methods: 1) a qualitative heuristic method based on observed end - of - winter Arctic Multi-Year Ice (MYI) 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 (CIS) contributions in June 2009 and June 2010, the 2011 forecast was derived using a combination of three methods: 1) a qualitative heuristic method based on observed end - of - winter Arctic Multi-Year
Ice (MYI) 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 (MYI) 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 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 predictors.
This is one reason why GISS does not currently use SST
data in the seasonal
ice region above 75N, even when this
data is seasonally available (as is increasingly the case due to diminishing
trends in
ice extent and better coverage due to satellite
data).
B. Martín - Español et al 2016 - Spatial and temporal Antarctic
Ice Sheet mass
trends, glacio - isostatic adjustment, and surface processes from a joint inversion of satellite altimeter, gravity, and GPS
data