By Anna-Marie Lever
Technology reporter, BBC News
Unmanned aircraft are to help scientists with research flights that are too dangerous or difficult for human pilots.
Robot planes have long been used by the military, but they are now being adapted for scientific use.
Noaa researchers (National Oceanic and Atmospheric Administration) say it could revolutionise the way the Earth's systems are monitored.
The agency has announced a $3m (£1.5m) investment into the technology.
"A big chunk of the atmosphere remains relatively unobserved. I think unmanned aircraft are a key to that solution and they will become ubiquitous in the coming decade," said Marty Ralph, a research meteorologist at Noaa's Earth System Research Laboratory, Colorado.
Co-worker Sandy MacDonald added: "They are great for the missions we call dirty, dull and dangerous."
The $3m will be invested into projects to use unmanned aircraft for three main purposes: to predict a hurricane's intensity, track how fast Arctic summer ice will melt and whether Pacific storms will flood the west coast of America.
Pilotless hurricane hunters
Pilotless hurricane hunters are able to sample continuously.
In November 2007 Noaa flew the first unmanned plane, called an Aerosonde, into hurricane force winds.
Scientists were able to monitor hurricane Noel using an "integrated observing concept" by combining data taken from manned aircraft, the Aerosondes and satellites.
Said Mr Ralph: "By getting these two looks at the same time and then the satellite looking from the top - we can really understand how the hurricane is getting its energy and maintaining it better."
Another advantage of the unmanned aircraft is continuous sampling, opposed to the snapshot values received from manned "hurricane hunters" which drop down tube-like, data-gathering devices to measure moisture, temperature and wind speed.
Mr Ralph explains: "What you can do with the Unmanned Aircraft System (UAS) is fly down in a continuous mode and keep sampling - essentially follow the storm so we can actually track changes. It is a very unique capability. We are getting the types of measurements we should not otherwise be able to get."
Spectrum of aircraft
August-October Hurricanes: small unmanned aircraft will fly into the eye of Atlantic and Caribbean hurricanes at low altitudes too risky for crewed aircraft.
Late 2008 Arctic climate change: large unmanned aircraft will observe sea ice conditions and track the locations of seal populations as the climate warms.
Spring 2009 Storms: low and high altitude unmanned vehicles will fly over the Pacific to study atmospheric rivers.
Future missions to monitor fisheries, track Greenland glaciers, preserve natural resources and examine murky plumes of volcanic emissions.
The scientists will investigate various unmanned aircraft models for the different mission needs.
The UAS used in hurricane Noel is know as a low altitude long endurance (LALE) plane. It is able to fly for a day, at 70 knots (129km/h) with a payload of a few pounds.
Mr MacDonald said: "Unmanned aircraft can go in so low that they get salt water on the wings."
On the other extreme is Global Hawk, which is a joint venture with Nasa. Global Hawk can fly up to 30 hours, approaches 300 knots (556km/h), and its creators claims it can cover half the planet in one mission while carrying a payload of 2000 pounds (907kg).
Mr Ralph added: "You can imagine the spectrum of different platforms in between those."