Tag: ocean

Take me to the river

marbles.jpg Climate news doesn’t just turn up in an RSS feed; sometimes it jumps right into your lap. A day or two ago, I discovered that a new paper about sea temperatures around New Zealand during the Eocene (50 million years ago) has significant implications for climate modelling and is based on fieldwork done very close to my home. Stuff reports:

Using sedimentary rocks from the bed of the Waipara River in North Canterbury, an international research group led by GNS Science palaeontologist Chris Hollis has reconstructed ancient sea temperatures. They found surface sea water exceeded 30 degrees Celsius, and water at the sea floor hovered around 20ºC during an episode of greenhouse gas-induced global warming that lasted for between two million and three million years. “These temperatures are at the extreme end of modern tropical water masses,” Dr Hollis said. Year-round sea surface temperatures of 25ºC to 30ºC are today found only at the equator.

At the time, New Zealand was much closer to the South Pole — below 50ºS — yet supported tropical flora and fauna. (GNS press release here).

Continue reading “Take me to the river”

Beautiful haze

ChathamIslands.jpg

I’m a sucker for pictures from space, and this morning’s offering from NASA’s Earth Observatory site is a stunning view of the Chatham Islands, snapped by NASA’s Aqua satellite last Saturday (click on the picture to see the full size image). The turquoise clouds in the sea around the islands are a bloom of coccolithophores, a kind of phytoplankton that plays a significant role in the climate system. They have tiny skeletons made of carbonate, and sequester carbon as they die and their skeletons fall to the ocean floor, but they also affect planetary albedo (by making oceans more reflective), and give off dimethyl sulfide, an important source of particles to seed cloud formation. More here, and here.

I’d be very surprised if this picture doesn’t show up in the newspapers tomorrow, because a) it’s beautiful, and b) NASA doesn’t charge for the use of its images.

[Title reference]

Celia of the seals

sealhat.jpg It appears that my wish is someone’s command. Last month, blogging on the continuing break-up of the Wilkins ice shelf, I noted a reference to “seal hats” as data gathering devices and expressed a wish to see them. And here they are! Little devices glued to the heads of elephant seals that gather data as the seals as they go about their daily business. A new paper in the Proceedings of the National Academy of Science explains:

Here, we show that southern elephant seals (Mirounga leonina) equipped with oceanographic sensors can measure ocean structure and water mass changes in regions and seasons rarely observed with traditional oceanographic platforms. In particular, seals provided a 30-fold increase in hydrographic profiles from the sea-ice zone, allowing the major fronts to be mapped south of 60°S and sea-ice formation rates to be inferred from changes in upper ocean salinity. […] By measuring the high-latitude ocean during winter, elephant seals fill a ‘‘blind spot’’ in our sampling coverage, enabling the establishment of a truly global ocean-observing system.

Abstract here, full paper here[PDF]. More coverage at New Scientist, e! Science News.

Once upon a time there was an ocean

Oldnorthpolemap.jpg The Arctic summer sea ice cover could be reduced by 2013 to “a few outcrops on islands near Greenland and Canada between mid-July and mid-September”, according to new research reported in The Observer [UK] today. The paper also suggests that this year could still see a new record minimum. Wieslaw Maslowski, the US Navy researcher who suggested in 2007 that the Arctic could be ice free by 2013, told Observer science editor Robin McKie:

‘It does not really matter whether 2007 or 2008 is the worst year on record for Arctic ice,’ Maslowski said. ‘The crucial point is that ice is clearly not building up enough over winter to restore cover and that when you combine current estimates of ice thickness with the extent of the ice cap, you get a very clear indication that the Arctic is going to be ice-free in summer in five years. And when that happens, there will be consequences.’

This is the first story I’ve found in a mainstream newspaper that has picked up on what those “consequences” might be, albeit in only the most general terms:

This startling loss of Arctic sea ice has major meteorological, environmental and ecological implications. The region acts like a giant refrigerator that has a strong effect on the northern hemisphere’s meteorology. Without its cooling influence, weather patterns will be badly disrupted, including storms set to sweep over Britain.

Or a run of warm wet summers.

The paper also talked to Mark Serreze from the NSIDC about the speed up in melt over the last week:

‘[…]Beaufort Sea storms triggered steep ice losses and it now looks as if it will be a very close call indeed whether 2007 or 2008 is the worst year on record for ice cover over the Arctic. We will only find out when the cover reaches its minimum in mid-September.’

The fat lady may just have got back into the limo and returned to her hotel for a snack.

[Update 12/8: The NSIDC has updated (11/8) its Arctic news page, commenting on the effect of storms on the ice, and noting that Amundsen’s long version of the NW Passage will be open soon.]

Ice ice baby

CTarctic4808.jpg The fat lady’s not yet in the building, but her limo’s outside the theatre. There’s another five or six weeks of melting to go, but there’s more than just sea ice melting in the Arctic, and more than my few meagre wagers riding on how summer turns out ‘oop North. Here’s a compendium of interesting recent stuff…

Continue reading “Ice ice baby”