Antarctic Research

[dbeyat45]

A 308-year record of climate variability in West Antarctica

• Abstract:
  
  We present a new stable isotope record from Ellsworth Land which provides a valuable 308-year record (1702-2009) of climate variability from coastal West Antarctica. Climate variability at this site is strongly forced by sea surface temperatures (SSTs) and atmospheric pressure in the tropical Pacific and related to local sea ice conditions. The record shows that this region has warmed since the late 1950s, at a similar magnitude to that observed in the Antarctic Peninsula and central West Antarctica, however, this warming trend is not unique. More dramatic isotopic warming (and cooling) trends occurred in the mid-19th and 18th centuries, suggesting that at present the effect of anthropogenic climate drivers at this location has not exceeded the natural range of climate variability in the context of the past ~300 years.

Researchers:

• Elizabeth R Thomas, Thomas J Bracegirdle, John Turner: British Antarctic Survey, Cambridge, UK
  Eric W Wolff: Department of Earth Sciences, University of Cambridge, Cambridge, UK

http://onlinelibrary.wiley.com/doi/10.1002/2013GL057782/abstract

 

[Diwundrin]

The carbon tax must be working then?

 

[dbeyat45]

Some new stuff from the British Antarctic Survey, reported on the BBC:

http://www.antarctica.ac.uk/bas_research/our_research/az/bedmap2/index.php

Scientists have their best measure yet for the amount of ice in Antarctica.
A detailed analysis of data compiled during 50 years of exploration shows the White Continent to contain about 26-and-a-half-million cubic km.
It is a colossal volume, and to put that in some sort of context: if this ice was all converted to liquid water, it would be sufficient to raise the height of the world's oceans by 58m.
These numbers come out of an international project known as Bedmap2.
This large cooperative effort - involving 60 scientists from 35 institutions based in 14 countries - has sought to put tighter constraints on some of Antarctica's fundamental statistics.
Bedmap2's new figure for the volume of ice is 4.5% more than previously thought.

 

[Warrigal]

Bedmap2's new figure for the volume of ice is 4.5% more than previously thought.Bedmap2's new figure for the volume of ice is 4.5% more than previously thought.

This does not mean that the amount of grown. It says there is more than previously estimated. The valleys are deeper than previously thought.

Improved ice bed, surface and thickness datasets for Antarctica

Bedmap2 is a new suite of gridded products describing surface elevation, ice-thickness and the sea floor and subglacial bed elevation of the Antarctic south of 60◦ S. We derived these products using data from a variety of sources, including many substantial surveys completed since the original Bedmap compilation (Bedmap1) in 2001. In particular, the Bedmap2 ice thickness grid is made from 25 million measurements, over two orders of magnitude more than were used in Bedmap1.

In most parts of Antarctica the subglacial landscape is visible in much greater detail than was previously available and the improved data coverage has in many areas revealed the full scale of mountain ranges, valleys, basins and troughs, only fragments of which were previously indicated in local surveys. The derived statistics for Bedmap2 show that the volume of ice contained in the Antarctic ice sheet (27 million km3) and its potential contribution to sea-level rise (58 m) are similar to those of Bedmap1, but the mean thickness of the ice sheet is 4.6 % greater, the mean depth of the bed beneath the grounded ice sheet is 72 m lower and the area of ice sheet grounded on bed below sea level is increased by 10 %.

The Bedmap2 compilation highlights several areas beneath the ice sheet where the bed elevation is substantially lower than the deepest bed indicated by Bedmap1. These products, along with grids of data coverage and uncertainty, provide new opportunities for detailed modelling of the past and future evolution of the Antarctic ice sheets.

 

[dbeyat45]

Can we rejoice in the fact that it hasn't shrunk?

.... or is that taking things too far?

It's a good thing there's no Arctic continent.