Wednesday, November 25, 2009

NZ Glaciers Continue to Retreat: Report


A recently-released report on the state of New Zealand’s glaciers has found they have, once again, lost a significant portion of their ice mass.The National Institute of Water & Atmospheric Research (NIWA), the NZ-based organisation which conducts both commercial and non-commercial research in the field of environmental sciences, has found “continued loss of glacier mass” in its end-of-summer survey according to its news release.

The statement quoted NIWA Snow and Ice Scientist Dr Jordy Hendrikx as saying the cause of the loss of glacial ice was the weather patterns over the course of the year from April 2008 to March 2009.

Dr Hendrikx said a combination of factors were to blame.

“This was mainly due to the combination of above normal temperatures and near normal or below normal rainfall for the Southern Alps during winter, and La Niña-like patterns producing more northerly flows creating normal-to-above normal temperatures, above normal sunshine, and well below normal precipitation for the Southern Alps particularly during late summer,” said the NIWA release.

Surveys of the glaciers, which have been taking place since 1977, use images taken from a small fixed wing aircraft of over 50 glaciers in the Southern Alps and Kaikoura to assess the well being of the glaciers. Researchers can then analyse the pictures taken to determine the position of the snowline after the summer melt but before the first winter snowfall, providing an index of the mass balance or “health” of the glaciers of New Zealand, says NIWA.

Though glacial retreat has been used as an indicator of the effects of global warming elsewhere in the world, the Institute warns that the situation is more complex in New Zealand as the mass and volume of the country’s glaciers are “…sensitive to changing wind and precipitation patterns as well as to temperature.”.

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