Sunday, September 6, 2015

What is happening to Antarctic ice shelves and why should we care?

Front of Ross Ice Shelf
Front of Ross Ice Shelf from research icebreaker Palmer.
Photo © Bruce Luyendyk

Antarctic ice shelves are thinning. What are ice shelves and are they important in any way? These massive floating sheets of ice border over a third of the Antarctic coast. 

Ice shelves are not frozen ocean. That is sea ice. In the simplest notion they are floating glaciers and part of the cryosphere cycle in Antarctica and Greenland. The largest Antarctic ice shelf is the Ross Ice Shelf, about the size of Texas (or France) and formed by the merging of glaciers flowing off the Antarctic continent. This shelf for example, is hundreds of meters thick (up to two thousand feet or more) and floats over sea floor hundreds of meters deeper.

This spring Science magazine published a research study on the state of the Antarctic ice shelves1.

Monday, April 27, 2015

16. Professor Numb Nuts in Antarctica

Excerpt from Chapter 16
Blizzard in Fosdick Mountains, Marie Byrd Land. Photo © Steve Richard.

[Scene: The Team is now at their deep field site in the Fosdick Mountains, northern Ford Ranges of Marie Byrd Land. Bruce and Dave are sharing a Scott tent and riding out an Antarctic blizzard for the first time. Bruce feels the call of nature and must face a cold reality…]

“Damn Dave, I need to go out for a BM. It’s a f**kin’ blizzard.” I said.

“Ha, ha, ha Bruce, send me a postcard, ha ha ha.”

This will be unpleasant. We didn’t have time or energy last night to build a latrine made of snow blocks we cut, and didn’t have a toilet tent. Geez, can I wait unit the blizzard stops? That could be days. Our training warned about constipation, a common problem with field parties. That would make my situation much worse.

With reluctant determination I put on fleece pants over my long johns, wind pants over the fleece pants, a windbreaker over my fleece jacket and another pair of socks. I moved to the entrance and grabbed my boots, put them on and then my balaclava hat and goggles. I put on my parka and gloves last, put TP in my pocket. I untied the canvas tunnel and started to crawl out through it. Dave drank his Raro, looked at me, shook his head, grinned.

I pushed open the tunnel, crawled into it, stuck my head out into the blizzard. I saw only violent white, could just see the shadow of the Chris and Steve’s tent. I jumped out into the snowstorm and stood up, wind blew horizontal across my body and pushed me sideways. From inside Dave grabbed the loose tunnel fabric and tied it closed.

Tuesday, February 17, 2015

Two Degrees Global Warming, Geoengineering, West Antarctic Ice Sheet collapse!

A break in the clouds on October 29, 2014, allowed scientists
the opportunity to fly over Pine Island Glacier—one of Antarctica’s
most rapidly changing areas. The flight was part of NASA’s

Operation IceBridge, a mission that makes annual surveys
 of Greenland and Antarctica with instrumented research aircraft.
Photo Michael Studinger

Is Earth headed towards warming of two degrees Celsius this century? If yes, can it be reversed? Should it be? How would it be done? 

Two recent publications offer some startling insights. The first by hockey-stick author Michael Mann estimates when the Earth can be expected to reach a level of 2°C warming (3.5°F) of the atmosphere. The answer it seems is very soon. Mann assumes business as usual in carbon emissions, which are increasing in amount every year, and the effect of the carbon dioxide (CO2) already in the atmosphere. These numbers are easy to come by, but he has to come up with a climate sensitivity model to translate the increase of CO2 in the atmosphere into warming. He determines that an equilibrium climate sensitivity about midway between estimates of the IPCC best-fit recent climate data. From this he projects forward and estimates the year Earth’s atmosphere reaches 2°C warming is 2036, twenty-one years from now. This is much sooner than estimates by the IPCC.