The blizzard that clobbered the eastern United States two weeks ago dumped more than a metre of snow in parts with 11 states declaring states of emergency, threatened more than 100 million people, cancelled more than 13,000 flights, closed hundreds of schools and government offices and led to economic loss estimated as high as $3 billion and at least 40 deaths.
It could have been worse. A heads-up from the squadron of weather satellites circulating the Earth allowed the US National Weather Service to gave a full week’s warning. Plenty of time to clear the roads, close the airports, put National Guardsman on standby and stockpile road salt.
Around 20 weather satellites – more if you count the all-important back-ups, waiting in the wings to take measurements should the originals fail – are currently zooming around the Earth.
They monitor everything from lightning strikes to sea surface temperature to particles flung by the Sun. Their orbits are deliberately staggered so that no point on Earth escapes their scrutiny. And whereas each country has the final word on what satellites and instrumentation they send up, it’s usually coordinated with the United Nations’ World Meteorological Organisation. All data is shared.
It’s those eyes in the sky, streaming petabytes of data into global weather prediction models run on supercomputers, such as the Australian Bureau of Meteorology’s Australis, that makes life-saving forecasts possible.
It wasn’t always like this …
TIROS-1 Television Infrared Observation Satellite-1
ESSA-1 Environmental Science Services Administration-1
GOES-A Geostationary Operational Environmental Satellite-A
TIROS-N next-generation Television Infrared Operational Satellite
OSTM/Jason-2 Ocean Surface Topography Mission/Jason-2
NOAA-N’ National Oceanic and Atmospheric Administration-N’
DSCOVR Deep Space Climate Observatory
CYGNSS Cyclone Global Navigation Satellite System