歌词
From VOA Learning English,
this is the Technology Report.
Many Americans start to closely follow weather reports
in the early fall.
During the Atlantic hurricane season,
predicting the strength and movement of
these huge storm systems is of crucial importance.
Thanks to new supercomputers,
meteorologists for the National Oceanic
and Atmospheric Administration (NOAA)
are getting better at predicting the weather
as far as six days out.
Hurricane Sandy hit the East Coast last October,
and caused deaths and widespread damage,
it was one of the costliest storm in U.S. history.
At the time, some people blamed meteorologists
for not correctly predicting the path of the storm.
But weather forecasting is extremely difficult, says Ben Kyger.
He is the Director of Central Operations
at NOAA's National Centers for Environmental Prediction
in College Park, Maryland.
"You’ve got major patterns in the atmosphere,
like the jet stream,
but you’ve also got little eddies, little currents,
little things happening all over the place.
All these little changes are interacting with each other,
continuously, all day long.
So if you look at it from above, from a satellite,
you see the atmosphere moving
and churning in big ways and little ways."
Ben Kyger says oceans are another issue
because they closely interact with the atmosphere
and have a huge effect on storms.
NOAA has spent about $20 million on two new supercomputers,
in an effort to improve the dependability of the forecasts.
"These computers generate the initial model guidance
that the whole forecast process depends on,
for all the weather information that you see,
with snowstorms, tornadoes, hurricanes,
how hot it’s going to be today
— all of your weather forecasts start
with what comes off of these supercomputers."
It takes a huge amount of computational power
to examine data from weather satellites,
ground stations and other sources.
It then take a lot of power to predict temperature,
air pressure, humidity and wind speed.
But human brains and experience
are still very important to the process.
Meteorologists at the National Centers
for Environmental Prediction scan the same data
that the supercomputers get before issuing a weather report.
"They are looking at lots of different models run of different computers,
and then they are creating that five-day forecast.
They use lots of scientific and subjective knowledge
from doing it year after year.
They know where the models are strong, where they’re weak
and they give us significantly better forecasts
than the models would do by themselves."
NOAA issues worldwide forecasts every six hours every day of the year.
The reports are free and are helpful for many countries
that cannot afford their own weather service.
NOAA continues working to improve its weather-forecasting abilities,
another upgrade of its weather-predicting supercomputers
is planed for as earlier as 2015.
And that is the Technology Report from VOA Learning English.
I'm June Simms.