Climate News from the science press

[BenBurch]

Start of 2012, March shatter US heat records

http://phys.org/news/2012-04-record-breaking-hot-year.html

(AP) -- It has been so warm in the United States this year, especially in March, that national records were not just broken, they were deep-fried.
Temperatures in the lower 48 states were 8.6 degrees above normal for March and 6 degrees higher than average for the first three months of the year, according to calculations by the National Oceanic and Atmospheric Administration. That far exceeds the old records.

The magnitude of how unusual the year has been in the U.S. has alarmed some meteorologists who have warned about global warming. One climate scientist said it is the weather equivalent of a baseball player on steroids, with old records obliterated.

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In March, at least 7,775 weather stations across the nation broke daily high temperature records, and another 7,517 broke records for night-time heat. Combined, that is more high temperature records broken in one month than ever before, Crouch said.

In a paper that NASA's top climate scientist, James Hansen, submitted to the journal Proceedings of the National Academy of Sciences and posted on a physics research archive, Hansen shows that heat extremes are not just increasing but are happening far more often than scientists thought.

What used to be a 1-in-400 hot temperature record is now a 1 in 10 occurrence, essentially 40 times more likely, said Hansen. The warmth in March is an ideal illustration of this, said Hansen, who also has become an activist in fighting fossil fuels.

 

[BenBurch]

Wettest April in UK since 1767 according to longest rainfall dataset

http://phys.org/news/2012-05-wettest-april-uk-longest-rainfall.html

(Phys.org) -- Last month was the wettest April on record according to data from the UK's longest running rainfall data collection station. Although April 2012 was widely reported to be the wettest drought this century, it is likely to be the wettest April in Oxford for almost 250 years.

That is according to Oxford University's Radcliffe Meteorological Station, which has been collecting temperature and rainfall data almost continuously since 1767. Situated in the garden of Green Templeton College on Woodstock Road, its data collection goes further back than any other rainfall record in the UK. Its observations are strictly in accordance with the standards laid down by the Meteorological Office.

Its data shows the rainfall measurement in Oxford for April 2012 reached 142mm, compared to a long-term mean of 43.7mm – producing three times more rainfall than usual over the month. April 2012 beat the previous record of April 2000 by about 5mm. Nearly a third of the rain fell in the 48 hours between 0900GMT on April 27 and 0900GMT on April 29 2012. The rainfall observations are made by the Radcliffe Met Station Observer, who observes daily meteorological readings at 0900GMT, the same time for 365 days of the year.

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[Wangler]

State of Himalayan Glaciers Less Alarming Than Feared

http://www.sciencedaily.com/releases/2012/04/120419143119.htm

"The majority of the Himalayan glaciers are shrinking, but much less rapidly than predicted earlier."

 

[BenBurch]

http://www.sciencedaily.com/releases/2012/04/120419143119.htm

"The majority of the Himalayan glaciers are shrinking, but much less rapidly than predicted earlier."

A disputed finding itself, btw, but I hope it's true, as well as the similar story about Greenland.

 

[BenBurch]

Climate scientists discover new weak point of the Antarctic ice sheet

http://m.phys.org/news/2012-05-climate-scientists-weak-antarctic-ice.html

The Filchner-Ronne Ice Shelf fringing the Weddell Sea, Antarctica, may start to melt rapidly in this century and no longer act as a barrier for ice streams draining the Antarctic Ice Sheet. These predictions are made by climate researchers of the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association in the coming issue of the journal Nature. They refute the widespread assumption that ice shelves in the Weddell Sea would not be affected by the direct influences of global warming due to the peripheral location of the Sea.

The results of the climate modelers from the Alfred Wegener Institute will come as a surprise to the professional world with the majority of experts assuming that the consequences of global warming for Antarctica would be noticeable primarily in the Amundsen Sea and therefore in the western part of Antarctica. "The Weddell Sea was not really on the screen because we all thought that unlike the Amundsen Sea its warm waters would not be able to reach the ice shelves. But we found a mechanism which drives warm water towards the coast with an enormous impact on the Fichner-Ronne Ice Shelf in the coming decades", says Dr. Hartmut Hellmer, oceanographer at the Alfred Wegener Institute and lead author of the study.

Using different model calculations, he and his colleagues Dr. Frank Kauker, Dr. Ralph Timmermann and Dr. Jürgen Determann as well as Dr. Jamie Rae from Met Office Hadley Centre, U.K., demonstrate that as a result of a chain reaction large ice masses could presumably slide into the ocean within the next six decades.

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[BenBurch]

Antarctic octopus tells story of ice-sheet collapse

http://m.phys.org/news/2012-05-antarctic-octopus-story-ice-sheet-collapse.html

Scientists have long been concerned that the massive West Antarctic Ice Sheet could collapse if global temperatures keep climbing. If it did, sea levels are predicted to rise by as much as five meters.

Now, genetic evidence from an Antarctic octopus reveals that this may have happened at some point in the not-too-distant past – possibly as recently as 200,000 years ago.

This suggests that scientists' concerns about the state of today's ice sheet could well be justified.

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[Warmer1]

Thanks for the posts Ben!

 

[r-j]

In the first study of its kind in Australasia, scientists have used 27 natural climate records to create the first large-scale temperature reconstruction for the region over the last 1000 years. The study was led by researchers at the University of Melbourne and used a range of natural indicators including tree rings, corals and ice cores to study Australasian temperatures over the past millennium and compared them to climate model simulations.

http://esciencenews.com/articles/2012/05/17/1000.years.climate.data.confirms.australias.warming

 

[bit_pattern]

Has anyone come across AGW Observer yet? A good reference

http://agwobserver.wordpress.com/

New research from last week 20/2012

Posted by Ari Jokimäki on May 21, 2012

• Transition from fossil fuels to biofuels might be bad idea from ozone layer perspective – Revell et al. (2012)
• Late 20th century warming was unusual and outside natural variability in Australasia during last millenium – Gergis et al. (2012)
• Is climate sensitivity less for solar forcing than for carbon dioxide forcing? - Andrews et al. (2012)
• Updated estimates of world ocean heat content and sea level change – Levitus et al. (2012)
• Radiosondes and reanalyses see positive trends in tropospheric water vapor over parts of Arctic – Serreze et al. (2012)
• El Niño has an influence to atmospheric carbon dioxide distribution – Jiang et al. (2012)
• Were historical population crises in China related to climate? – Lee & Zhang (2012)
• Trying to see annual tree-rings in permanent growing readiness trees of Ethiopia – Krepkowski et al. (2012)
• Weakening of summer monsoon has increased aerosol concentrations over eastern China – Zhu et al. (2012)
• Differences in cloud feedbacks continue to be important contributors to 2.1–4.7 K range of equilibrium climate sensitivity – Andrews et al. (2012)
• Observed tropical tropopause cooling might not be statistically significant – Wang et al. (2012)

New research from last week 20/2012

 

[BenBurch]

Finding fingerprints in sea level rise

http://m.phys.org/news/2012-05-fingerprints-sea.html

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At the heart of the new technique is the idea, first proposed by Mitrovica and others more than a decade ago, that variability in sea level changes amount to a "fingerprint" researchers can use to identify the source of water pouring into the oceans.

With the public unconvinced about the effects of climate change, Mitrovica proposed the fingerprint idea as a way to refute the argument that melting ice sheets would cause a uniform sea level rise, he said, "like what you see when you turn on the tap in the bathtub – it all goes up uniformly." Rather than a uniform rise in sea level, skeptics pointed to records that showed levels rising in some areas and dropping in others as evidence that man-made climate change was a myth.

But that variability is exactly what researchers expect to see, Mitrovica said.

"As ice sheets around the world melt, there is an extremely variable effect on sea level," Mitrovica explained. "That variation is actually very beautiful – it has information embedded in it. By looking at the differences in sea level changes around the globe, we should, in principle, be able to determine if the changes are the result of melting in Alaska, Greenland, Antarctica, or elsewhere."

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[BenBurch]

Black carbon, tropospheric ozone most likely driving Earth's tropical belt expansion

http://m.phys.org/news/2012-05-black-carbon-tropospheric-ozone-earth.html

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Observations show that the tropics have widened by 0.7 degrees latitude per decade, with warming from greenhouse gases also contributing to the expansion in both hemispheres. To study this expansion, the researchers first compared observational data with simulated data from climate models for 1979-1999. The simulated data were generated by a collection of 20 climate models called the Coupled Model Intercomparison Project version 3 or "CMIP3."

The researchers found that CMIP3 underestimates the observed 0.35 degrees latitude per decade expansion of the Northern Hemisphere tropics by about a third. But when they included either black carbon or tropospheric ozone or both in CMIP3, the simulations mimicked observations better, suggesting that the pollutants were playing a role in the Northern Hemisphere tropical expansion.

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"Both black carbon and tropospheric ozone warm the tropics by absorbing solar radiation," Allen explained. "Because they are short-lived pollutants, with lifetimes of one-two weeks, their concentrations remain highest near the sources: the Northern Hemisphere low- to mid-latitudes. It's the heating of the mid-latitudes that pushes the boundaries of the tropics poleward."

Allen further explained that with an expansion of the tropics, wind patterns also move poleward, dragging other aspects of atmospheric circulation with them, such as precipitation.

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Read the article, was hard to summarize with an excerpt.

 

[Lowpro]

Interesting article

http://arstechnica.com/science/2012/06/yet-another-study-confirms-global-warming-is-human-caused/

They found that the anthropogenic “fingerprint” was apparent in the observed temperature record at the 99 percent confidence level. That means the observed warming is beyond the variability seen in model simulations where greenhouse gases are kept constant, but is exactly what the models predict for a world in which humans change the composition of the atmosphere.

Nature article:

http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate1553.html