ANZICE

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What is ANZICE? The ANZICE Group ANZICE News

What is ANZICE?

ANZICE (Antarctica-New Zealand Interglacial Climate Extremes) is a scientific research programme funded by the NZ Foundation for Research Science and Technology and operating from the Antarctic Research Centre at Victoria University of Wellington. It is closely aligned with the FRST-funded “Global Change Through Time” programme at GNS Science and links with the ice core, gas analysis group at NIWA.

It seeks to understand the likely response of the New Zealand - Antarctic region to a warmer world. To achieve this aim, the project focuses on environmental changes that occurred during peak warm periods in the past when the atmosphere and surface ocean were up to 3 degrees C warmer than now. Such temperature increases are in line with those indicated for the next century by the Intergovernmental Panel on Climate Change or IPCC. We believe that by deciphering detailed environmental records of the previous warm periods, we can provide a template for the future.

A record of greenhouse gases [carbon dioxide, methane] for the past 400,000 years as preserved in the Vostok Ice Core from Antarctica. Temperatures derived from the core show ice ages when average temperatures were 6 to 8 degrees C cooler than now. Such periods were punctuated by warm phases such as Stage 5e (red arrow) when temperatures were around 2 degrees C warmer than today’s average. ANZICE will focus on those warm phases as case studies for what to expect in the future.

By evaluating past warm phases (ANZICE) aims to:

• provide reconstructions of environment responses to rises in temperature;
• develop the reconstructions into models to help identify potential changes and consequences for a projected warmer world;
• apply model results to guide policy for New Zealand’s future.

To achieve these goals, ANZICE will take a three pronged approach:

• Antarctic drivers of ocean-climate will use new and existing records from ice cores to determine how Antarctica’s climate and ocean behaved during past warm phases such as occurred around 7,000-9,000 years ago (Holocene Climatic Optimum) and 125,000 years ago (Last Interglacial Period or Stage 5e).
• Southern Ocean-NZ responses will rely on environmental data contained within sediment cores from the Southern Ocean to identify past responses of ocean waters and currents. The impact of such changes on New Zealand will be gauged from glacial and lake records preserved onshore.
• Analogue and computer models will draw on the above research results to develop models that help clarify our view of the future.

ANZICE introduces new innovations that greatly improve the ability to analyse, interpret and apply records of previous warmer climates.

Ice cores, collected from coastal sites, contain information with annual detail similar to tree rings. The cores are expected to recover ice at least 10,000 years old, and so will include the Holocene Climatic Optimum. Contained within the ice is a host of environmental clues:

• gases reveal the composition of the atmosphere;
• isotopes of hydrogen and oxygen fingerprint atmospheric temperatures;
• major and trace chemical elements reflect changes in the atmospheric circulation and storminess;
• dust contents shed light on winds, and the state of lands bordering Antarctic continent;
• sulphates, fluoride and chloride identify volcanic activity;
• the compound, methylsuphonate, is a measure of sea-ice concentration.

The business end; an ice core is partly extruded from the corer. Source: Nancy Bertler, VUW/GNS.

In cold, ultra-clean conditions an ice core is prepared for sampling. Source: Nancy Bertler, VUW/GNS.

Ice cores and samples will be stored and processed in the newly established, state-of-the-art NZ Ice Core Research Laboratory at the National Isotope Centre in Lower Hutt. This laboratory is a joint venture between GNS Science and Victoria University of Wellington, with assistance from NIWA. The ice will be analysed in laboratories at GNS Science, Victoria University, the National Institute of Water and Atmosphere, universities of Maine and Hawaii (US) and the Alfred Wegener Institute (Germany).

Sediment cores from the ocean also hold a wealth of environmental information, much of which is tied up in the remains of plankton, in particular foraminifers. As these animals form their sand-sized shell, they incorporate chemical elements and isotopes from the ocean. For example, the ratio of magnesium to calcium (Mg/Ca) relates to ocean temperature, and the ratio of barium to aluminium (Ba/Al) gives an insight into ocean fertility that involves the production of plant and animal plankton – the foundation of the marine food chain. To unravel these chemical fingerprints ANZICE will deploy the University of Victoria’s laser ablation, inductively coupled plasma, mass spectrometer. This new analytical system deploys a laser beam to “drill” through minute objects, measuring liberated elements en route.

An electron microscopic view of a foraminifer shell, the size of a sand grain, that has been “drilled” with a laser to make over 140 analyses of elements per hole. Source: Professor S. Eggins, Australian National University.

A suite of analyses made by laser ablation as it “drilled” (from left to right) through the shell wall of the foraminiferal species, Neogloboquadrina dutertrei. As the laser passed through the 20 micron thick wall (a hair strand is 60-90 microns thick), a suite of measurements were made that included magnesium (Mg), strontium (Sr), manganese (Mn), barium (Ba) and zinc (Zn). Source: Professor S. Eggins, Australian National University.

The use of observation-based and computer-based models is another feature of ANZICE. Information from the ice and sediment core studies will be compiled to form observational models to help answer basic research questions, for example, “How did the Antarctic environment appear during the Last Interglacial period, 125,000 years ago, and what was the impact on the Southern Ocean and New Zealand?” Answers to such questions will help guide and verify the computer models to give a measure of confidence in their results. Once operational, the computer models will improve our ability to understand how an environment may change under various warmer world conditions. By changing the drivers that control a model such as ocean and air temperatures, greenhouse gas concentrations, wind strength and other factors, it becomes possible to gain an insight into potential environmental responses, all the while checking the results with observations of the past.

The future of New Zealand’s glaciers, such as the Franz Josef (pictured), will be evaluated in light of their importance to water resources, tourism and local climate. Using historical meteorological data, field observations and reconstructions of past environments, supplemented with computer models, ANZICE will be in a good position to advise on the fate of glaciers in a warmer New Zealand. Source: Peter Barrett, VUW.

As research results and computer models take shape, ANZICE will turn to communicating the information to the public and governmental agencies involved with climate change. This initiative is not only to inform, but to help shape policy.

An example of output from a computer-based model that is presently under development for the Southern Alps. Termed a “regional energy balance model”, it aims to quantify changes in snow fall and snow/ice melt that have occurred in the past, and predict what changes might occur as temperatures rise in the future. In this image (arrow indicates Tasman Glacier) the blue areas signify net accumulation of snow, while red areas signify net loss of snow and ice. The snowline (where accumulation equals melt) is shown in white. Source: Brian Anderson.

The ANZICE Group

The three objectives in ANZICE are led by:

• Nancy Bertler - Antarctic drivers of ocean-climate;
• Gavin Dunbar - Southern Ocean-NZ responses;
• Andrew Mackintosh – models;
• Sean Weaver – policy.

They will be supported by Brian Anderson (glacier modeling), Joel Baker (geochemistry), Peter Barrett (past Antarctic climates), Lionel Carter (past oceanic environments), Tamsin Falconer (project administration), Alex Pyne (ice core drilling) and Tim Naish (ANDRILL and past ice/ocean environments). ANZICE will also benefit from the postgraduate research of Annette Bolton (past ocean change), Jeremy Fyke (ice-ocean-climate modeling), Julia Bull (ice core chemistry) and Rachael Rhodes (ice core chemistry).

ANZICE programme leader is Lionel Carter.

ANZICE News

April 2009:

• ANZICE-GCT Briefing , 30 January 2009.
• The programme contract with the Foundation for Research Science and Technology signed.
• ANZICE presentations made to Sir David King, Science Advisor to the UK Government.
• Gavin Dunbar, Tamsin Falconer, Alex Pyne participate in the Antarctic Drilling (ANDRILL) Programme with which ANZICE has close research links.
• Nancy Bertler begins site surveys for ice core drilling in Antarctica.