Spotlight on: Macquarie Island
Macquarie Island weather station is one of a the network of stations used for climate change monitoring.
Where is it?
It is located in the Southern Ocean, about half-way between Australia and Antarctica (54°3' S 158°57' E).
What part does it play in the network?
Macquarie Island station is a part of the Australian Climate Observations Reference Network (ACORN). It provides high-quality, ground-based temperature and rainfall records which allow scientists to better analyse long-term trends and changes in the climate.
Geography
Macquarie Island is a long, narrow, steep-sided island forming a plateau, 34 km long and 5.5 km wide at its broadest point, lying approximately in a north-south direction. It is the only place on earth formed entirely of oceanic crust and rocks from the earth's mantle, deep beneath the earth's surface.
History
Macquarie Island is a Tasmanian State Reserve which is managed by the Tasmanian Parks and Wildlife Service. It was inscribed on the World Heritage List in 1997 as it is an island of great natural diversity and unique geological values.
The current meteorological station was established by the Australian National Antarctic Research Expeditions in March 1948 and is situated on the isthmus at the northern end of the island, at 6m above mean sea level.
Observations of temperature commenced in 1948. There was a change in the instrument enclosure (but not a relocation) in 1979. An automatic weather station was installed in August 1992 which was upgraded to a new type in April 2003. However, manual readings taken at the site are still used as the primary observations. The area within 20 m of the equipment is mostly covered by short natural grass, with low tussock beyond.
Climate
Macquarie Island has a maritime climate characterised by frequent rainfall, westerly gales and cloudy skies. Temperatures are moderated by the southern ocean with low day to day and seasonal variability. Temperatures in summer are typically near 10 °C during the day dropping to 5 °C at night. Winter temperatures typical vary from 5 °C during the day to around 2 °C at night.
The island has seen a significant increase in rainfall in recent decades, amounting to an increase of nearly 200 mm since the middle of the last century (around 20%). Temperatures have warmed by approximately 0.5 °C, a rate which is somewhat lower than mainland Australian stations further north.
