As weather forecasters, here at MetService we spend a lot of our time poring through data: data from weather stations, data from satellites and radar, from weather balloons and also webcams. This information is all useful for understanding what the weather is doing right now – but how do we know what might happen in the future? Understanding the current weather helps us understand what might come next, but information from numerical weather models also plays a very important part.

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.

Written by Erick Brenstrum, Meteorologist

We remember our war dead on Anzac Day, 25th April, the anniversary of the landings at Gallipoli in World War I. But our heaviest losses in that war occurred on the Western Front. Our worst day was 12 October 1917 – the First Battle of Passchendaele. New Zealand lost 1,000 soldiers in two hours because the high command ignored the effect of heavy rain on the battlefield. The Ypres Salient, in Belgium, where the campaign took place was low lying. Prior to the war the water table was 35 centimetres below the surface.

What would New Zealand’s history be like without the First and Second World Wars? Blame the terrible Russian winter and Napoleon’s folly according to historian Adam Zamoyski in his riveting book 1812 Napoleon’s Fatal March on Moscow. The losses suffered in the invasion, particularly to his cavalry, ensured Napoleon’s downfall the following summer. That led to an aggressive Germany unified under a militaristic Prussia while in Russia, the Tsar came to believe he was God’s instrument on Earth.

Written by Erick Brenstrum and originally published in the New Zealand Geographic Issue 111 Sept-Oct 2011 

Written by Erick Brenstrum and first published in New Zealand Geographic 96, March-April 2009 

We think of Benjamin Franklin as American, but for the first seventy odd years of his life he thought of himself as British. In turn, the British thought him one of theirs and embraced Franklin’s ideas and inventions as British discoveries.

Rugby and fog do not go well together. Fortunately, in the days when rugby was played in the afternoon, they did not meet up much, except for the occasional test in Scotland when the All Blacks disappeared into the “gloom” as they scampered in a late try.

However, the introduction of night-time rugby gave fog a chance to get on the field for some game time. Especially in the United Kingdom, where evening games sometimes have to be cancelled when fog turns up.

The All Blacks were due to play Scotland in Auckland on 14 June 1975 when a major storm hit New Zealand. Torrential rain fell over many parts of the country inundating farmland from Northland to Canterbury. Roads in Northland were cut by floodwaters metres deep and the Mangakahia River rose 10 metres above normal.

The first test between the All Blacks and the Lions in 1930 was played at Dunedin’s Carisbrook Park just after a snowstorm. Rain started in the morning then turned to snow during the curtain raiser. It became almost impossible to make out the players and some of the crowd went home while others sheltered under blankets and umbrellas.