Weather balloons

Weather balloons have been released for decades around New Zealand to record data throughout the lower layers of the atmosphere. They have been used to measure everything from the base of low cloud to atmospheric wind and temperature profiles. One of the first people to use weather balloons was French Meteorologist Léon Teisserenc de Bort. He released hundreds of weather balloons from his observatory in Trappes, France. His experiments lead to the discovery of the tropopause and the stratosphere.

Christmas past

Christmas Day in New Zealand can be a hit and miss affair, weather wise. Some years, a High arrives in time for Santa. Christmas Day 2009 was beautifully fine and warm across the country, with Dunedin hitting 32°C, and many other centres approaching  25°C.

Midday analysis for 25th December 2009. Midday analysis for 25th December 2009.

Radar and mariners – a long relationship

The development of modern radar started in 1886, when German physicist Heinrich Hertz showed that radio waves could be reflected from solid objects. In 1904, another German, Huelsmeyer, was the first to build a simple ship detection device, successfully detecting a ship in dense fog. In the pre-war period (the 1930s), many nations were working on radar devices. A major advance occurred once systems were developed that allowed short ‘pulses’ of radio energy to be generated, allowing the range of the object to be determined by timing the pulses.