As the northern hemisphere starts to warm (rather rapidly in the USA), climate watchers’ thoughts turn to melting ice, and to tell us what happened last year and what might be in store this summer, Glenn and Gareth welcome back Greenland expert Jason Box from the Byrd Polar research Centre at Ohio State University. It’s a wide ranging and fascinating discussion, not to be missed. John Cook looks at the differences between sea ice in the Arctic and Antarctic, and we have news coverage of the new HadCRUT4 global temperature series, summertime in winter in the USA, worrying news about sea level from the Pliocene, a new report on climate change in the Pacific, and new developments in solar power and biofuels.
News & commentary: [0:03:30]
Hadley Centre publishes updated global temp series, includes Arctic for first time, shows 2010 was hottest year – formerly 1998.
Astounding US winter “heatwave” continues: Joe Romm at Climate Progress
From Jeff Masters on the day we were recording (21/3/12): http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2056
International Falls, Minnesota hit 78°F yesterday, 42° above average, and the 2nd hottest March temperature on record in the Nation’s Icebox. The record of 79°F was set the previous day. Remarkably, the low temperature for International Falls bottomed out at 60°F yesterday, tying the previous record high for the date. I’ve never seen a station with a century-long data record have its low temperature for the date match the previous record high for the date. Yesterday was the seventh consecutive day that International Falls broke or tied a daily record. That is spectacularly hard to do for a station with a century-long weather record. The longest string of consecutive records being broken I’m aware of is nine days in a row, set June 2 – 10, 1911 in Tulsa, Oklahoma (with weather records going back to 1905.) International Falls has a good chance of surpassing nine consecutive records this week.
“6th, 7th Consecutive Days of Record-Warmth Likely Updated: Monday, 19 Mar 2012, 12:37 PM CDT Published : Monday, 19 Mar 2012, 7:38 AM CDT Sun-Times Media Wire Chicago – In what meteorologists are calling a “historic and unprecedented” streak, the Chicago area should hit the sixth day in a row of record warm temperatures on Monday, even on the last day of winter.”
Even if humankind manages to limit global warming to 2 degrees C (3.6 degrees F), as the Intergovernmental Panel on Climate Change recommends, future generations will have to deal with sea levels 12 to 22 meters (40 to 70 feet) higher than at present, according to research published in the journal Geology.
…until recently there has been limited reliable detailed scientific information available to [Pacific Island] countries. A major new report recently released by the Bureau of Meteorology and CSIRO is helping to fill this gap. It provides the most comprehensive scientific analysis to date of climate change in the Pacific region.
The 530 page, two-volume scientific report called “Climate Change in the Pacific: Scientific Assessment and New Research” shows clear evidence of how the climate in the Pacific has changed and may change in the future.
Jason Box, Assoc. Professor in the Department of Geography, Byrd Polar Research Center,
The Ohio State University, Columbus, Ohio, USA.
NASA MODIS Arctic mosaic
Arctic Report Card, highlights
- Arctic average surface air temperature remained high in 2011, ~1.5 C above the 1981-2000 baseline
- shift in the Arctic [Ocean] system since 2006
- persistent decline in the thickness and extent of the summer sea ice cover, and a warmer, fresher upper ocean.
- As a result of increased open water area, biological productivity at the base of the marine food chain has increased
- sea ice-dependent marine mammals continue to lose habitat.
- increases in the greenness of tundra vegetation
- increases in permafrost temperature
- more downward sensible heat and positive albedo feedback, reduced sea ice
- loss of habit for walrus and polar bears.
- less duration of solid platform for seal to ‘pup’
- Possibly linked to recent changes in wind patterns, ozone concentrations in the Arctic stratosphere during March 2011 were the lowest ever recorded during the period beginning in 1979.
- Higher temperatures in the Arctic and unusually lower temperatures in some low latitude regions are linked to global shifts in atmospheric wind patterns.
Links to “Weird Weather”
- While oceanic and atmospheric patterns such as El Niño, La Niña, and the North Atlantic Oscillation have been blamed for the spate of unusual weather recently, there’s now a new culprit in the wind: Arctic amplification…
- new Arctic amplification (enhanced Arctic warming relative to that in mid-latitudes) news from: Francis and Vavrus (2012), Evidence linking Arctic amplification to extreme weather in mid-latitudes, Geophys. Res. Lett., 39, L06801, doi:10.1029/2012GL051000
- a slower eastward progression of Rossby waves in the upper-level flow
1) weakened zonal winds,
2) increased wave amplitude.
may cause more persistent weather patterns in mid-latitude
A persistent and strong negative North Atlantic Oscillation (NAO) index was responsible for southerly air flow along the west of Greenland, which caused anomalously warm weather in winter 2010-11 and summer 2011.
- Greenland ice sheet mass loss has accelerated in the past decade responding to combined glacier discharge and surface melt water runoff increases.
- During summer, absorbed solar energy, modulated at the surface primarily by albedo, is the dominant factor governing surface melt variability in the ablation area.
- Using satellite observations of albedo and melt extent with calibrated regional climate model output, we determine the spatial dependence and quantitative impact of the ice sheet albedo feedback in twelve summer periods beginning in 2000.
- We find that while the albedo feedback is negative over 70 % of the ice sheet, concentrated in the accumulation area above 1500 m, positive feedback prevailing over the ablation area accounts for more than half of the overall increase in melting.
- Over the ablation area, year 2010 and 2011 absorbed solar energy was more than twice as large as in years 2000–2004.
- Anomalous anticyclonic circulation, associated with a persistent summer North Atlantic Oscillation extreme since 2007 enabled three amplifying mechanisms to maximize the albedo feedback:
- (1) increased warm (south) air advection along the western ice sheet increased surface sensible heating that in turn enhanced snow grain metamorphic rates, further reducing albedo;
- (2) increased surface downward solar irradiance, leading to more surface heating and further albedo reduction; and
- (3) reduced snowfall rates sustained low albedo, maximizing surface solar heating, progressively lowering albedo over multiple years.
- The summer net radiation for the high elevation accumulation area approached positive values during this period.
- while negative feedback has been reducing impact of warming, the surface radiation budget has gotten more positive, seems a threshold is about to be crossed! All what is needed more is another decadal trend increase like the last decade, THIS IS LIKELY! It is reasonable to predict that we will observe mid summer (mid July) melting over 100% of the ice sheet surface. Max melt extent was ~65% in 2010.
- The area and duration of melting at the surface of the ice sheet in summer 2011 were the third highest since 1979.
- The area of marine-terminating glaciers continued to decrease, though at less than half the rate of the previous 10 years.
- In situ measurements revealed near record-setting mass losses concentrated at higher elevations on the western slope of the ice sheet, and at an isolated glacier in southeastern Greenland.
- Total ice sheet mass loss in 2011 was 70% larger than the 2003-09 average annual loss rate of -250 Gt y-1. According to satellite gravity data obtained since 2002, ice sheet mass loss is accelerating.
- “holistic” glacier study, Store Glacier, 70 N W Greenland…the idea is to observe the system not just make and analyze this or that measurement
- in-situ crevasse widening measurements x 2
- water filled crevasse depth measurements x 2
- continuous GPS x 3
- seismometers x 3
- time lapse cameras
- tide gauge
- tidal modulation of flow dynamics
- calving tsunamis
- multi-beam swath sonar repeat survey of sub marine glacier front
- hydrographic surveying (temperature, salinity, current; vs depth)
- heat and water mass budget
- acoustic doppler current profiler
- aircraft and satellite remote sensing data
Debunking the sceptic [1:01:50]
John Cook from skepticalscience.com talks about Antarctic sea ice: