Climate scientists have turned to the United States and Australian navies to deploy robotic measuring devices in the Indian Ocean where pirates have made the area too dangerous for researchers.

About a quarter of the Indian Ocean is now off limits to climate scientists trying to complete a network of deep ocean devices that gather data crucial to climate change studies and weather forecasts.

We can't send anybody in that area. Research voyages have been canceled and I know there's a report of at least one ship that hired an armed escort, said Ann Thresher, an oceanographer with Australia's Commonwealth Scientific and Industrial Research Organization.

That's pretty extreme when you're talking about climate research, she told Reuters from Hobart.

Thresher said the northwest Indian Ocean played a crucial role in weather patterns in Australia and South Asia, where droughts or floods can cause major disruption to global food prices and trigger large insurance losses.

In particular, data from the Indian Ocean such as salinity and water temperatures and weather observations from ships were crucial for long-range forecasts.

Without those observations, we can't monitor that as accurately. Which means the predictions that scientists make that tells farmers how much rain are going to get or if there is going to be flooding in Queensland is not as accurate, she said.

The robotic measuring devices, called Argos, are about two meters (six feet) long and drift between the ocean surface to a depth of about 2,000 meters, before resurfacing to send data via satellite.

The Argos measure salinity and temperature and form part of a global monitoring effort to see how the world's oceans, which soak up large amounts of heat, are responding to a warming world. Oceans shift heat around the globe and drive the world's weather.

About 30 countries contribute to the multi-million dollar program that deploys and replaces the $19,000 floats.

The program is heavily reliant on commercial shipping and chartered vessels to deploy Argos globally but the threat from Somali pirates meant navies were the only option this time.

The devices will be deployed over the next few months in parts of the northwest Indian Ocean.

(Reporting by David Fogarty; Editing by Sugita Katyal)