Field: So when we look at a global picture of fire, you can see fire everywhere
on all continents. And at some level they're similar
in that it's vegetation that's burning, but the drivers of those can be
very different. In North America, for example,
fires can be started by lightning, by natural factors, by
people, often accidentally, and the explosive fires
there that we see on TV are driven by the variability
in the weather, so high winds at the surface for example. In other
areas, in South America for example, wind-driven fires are less
of an issue. It's primarily related to the land use. So
using fire for land clearing and land preparation.
In those cases, it's getting an accurate picture of the overall dryness
of that area. VO: NASA has a long history of monitoring fire
and smoke using different satellites in the Earth Observing System. Data from the
Global Precipitation Measurement mission, or GPM, and other satellites and
models gives us information on rainfall, temperature and land cover, which
in turn, create a more complete picture of a vegetation fire starting and spreading.
That's the thinking behind the Global Fire Weather Database, the first
globally consistent fire weather dataset for fire researchers and managers.
Field: So the Global Fire Weather Database is designed to get at the
underlying conditions that drive those fires. Really focused
on the meteorological aspect and to be used alongside some
of the other risk factors. As we learn how to make use of the
satellite data in driving these calculations, from GPM in particular,
that can translate into actual operational products used, for example,
by the meteorological services in different countries
for their localized fire weather products.
A good example is in Indonesia, which has a very serious fire problem.
It's all related to land clearing, and one issue there
is that it's happening in very remote regions. And in those places
there's very little data. It's not a data-rich environment, and so you're limited
by the accuracy of the picture you can get.
So in that case, when we use calculations based on GPM data,
it fills in all of those gaps. And we've seen that over
the past couple of years for some of its severe fire episodes
that we get a much better picture of where the dry regions are compared
to where it's very rainy. And those can be very close together
because of how localized rainfall can be in the tropics.
VO: Far away from the tropics, the Global Fire Weather Database is used
to assess risk in Canada. In 2017, abnormally
hot and dry weather, combined with stressed forests, led to severe
fires throughout British Columbia. Through July and August, stretches of high
fire risk in the interior led to periods of extreme fire behavior
and the highest annual recorded burned area for the province.
The impact from these fires isn't just on the ground. Plumes of smoke
can travel and pollute the air beyond the source. Field: In some cases we
can see smoke plumes from Northern Canada transported over the
Atlantic and arriving in Europe. In the most extreme cases, when
those fires are really hot, the smoke from those fires can be
ejected directly into the lower stratosphere.
It's like a small volcano. And then can persist in
the lower stratosphere for months. VO: Fire weather data based on satellites like
GPM continue to help researchers understand the conditions under which those extreme
fire events occur and how things may change over time.