"It must be so pretty with all the dear little kangaroos flying about," says the Duchess of Berwick in Lady Windermere's Fan. . And indeed, judging by Home and Away and Neighbours, , most of us would agree that Australia seems to be a very pleasant little spot. But the ways of the weather there are rather strange.
The most obvious meteorological complication is that the seasons are reversed. Christmas comes in the middle of summer, and what passes for winter in Australia occurs in July and August. A northern visitor may also be confused by funny names; they sometimes call their hurricanes "willy-willies", , and they experience strange phenomena we have never heard of - like "Cock-eye Bob", a sudden squall associated with thunder and lightning that lurk around the northwest coast.
But there are real problems with the local weather map. We are all familiar with Buys Ballot's law as it applies in the vicinity of Europe: it dictates that if you stand with your back to the wind, low pressure is to your left, which translated on to the weather map means that the wind blows in an anti-clockwise direction around centres of low pressure, and clockwise around highs. All is reversed in the southern hemisphere: the winds blow clockwise around depressions, and anti-clockwise around anticyclones.
In Europe, too, the main frontal activity lies to the south of each depression. The typical low has a triangular wedge of warm air embedded in it in such a way that the apex of the triangle points to the north, towards the centre of the depression. This wedge, bounded by a warm front at its leading edge and a cold front to the rear, is what meteorologists call the "warm sector". But in the southern hemisphere, everything is reversed: over Australia, the warm sector is on the northern edge of a depression, with its apex pointing south, and the warm and cold fronts are swept in a clockwise direction around the low. Australian weather systems are, as it were, upsidedown and back-to-front.
It may be, for some reason, that you might like to know more about these meteorological idiosyncrasies in the antipodes, and if so, the Irish Meteorological Society provides you with an ideal opportunity later on today. Ann Farrell is a meteorologist with the Australian Bureau of Meteorology, currently on secondment to Met Eireann's Central Forecast Office in Glasnevin, Dublin. Her talk, at 8 p.m. this evening, is titled "The Weather Down Under", and will take place at the usual venue for such events, Room G32 in the Earlsfort Terrace premises of what we used to know as UCD.