Weather Glossary - Y
The interval required for the earth to complete one revolution around the sun. A sidereal year, which is the time it takes for the earth to make one absolute revolution around the sun, is 365 days, 6 hours, 9 minutes and 9.5 seconds. The calendar year begins at 12 o'clock midnight local time on the night of December 31st-January 1st. Currently, the Gregorian calendar of 365 days is used, with 366 days every four years, a leap year. The tropical year, also called the mean solar year, is dependent on the seasons. It is the interval between two consecutive returns of the sun to the vernal equinox. In 1900, that took 365 days, 5 hours, 48 minutes, and 46 seconds, and it is decreasing at the rate of 0.53 second per century. This decrease is due to the slow precession of the Earth's axis of rotation.
Perth has recorded its fourth consecutive day of temperatures above 40 degrees Celsius, equalling a record that has stood for more than 80 years, as a heatwave continues to grip the city.
Farm Management Deposits changes will give farmers chance to help themselves, once they have cash to spare
The Federal Government has introduced legislation to overhaul the Farm Management Deposits scheme, which it says will help farmers to help themselves.
The first ten days of February have set a new record for Hobart with each day breaking the 21 degree mark, although a series of fronts on the forecast will bring a cooler change.