Satellites measure the status of the Planet’s water resources.
2015-8-3
来源:未知
点击数: 3722 作者:未知
The cycle of meetings continues on the contribution of satellites to the protection of natural resources proposed by the United States Pavilion at Expo Milano 2015, and hosted the conference Where is the water? How NASA measures water resources from space. The exceptional speaker for the event was Gerald Bawden, Program Scientist at NASA Headquarters. The Universal Exposition visitors, greeted on the Pavilion’s terrace, listened to the latest information on NASA satellite missions directly from the voice of one of its expert scientists. In particular Dr. Bawden spoke of satellite technologies that allow monitoring the planet’s water cycle, i.e., for example the rain pattern, the level of the tides, the status of the glaciers and even the status of water reserves in the subsoil.
The eye of the satellite
How much groundwater is there still in California or in India? How much has the polar icecap melted? How much is it raining in Europe? Moreover, what about the sea currents? When will there be the next hurricane? These are some of the questions that NASA is able to answer through the information captured by the orbiting satellites, both its own and those launched by space agencies of other cooperating countries. A great deal of valuable information that is growing constantly and that space scientists collect and make available freely on the internet for anyone to access and use. Particularly important data on the state of freshwater reserves, a vital resource for human survival and life in general. Today, thanks to special radars and laser beams, satellites are able to measure parameters like the amount of water in the subsurface and the rainfall pattern. Technologies are constantly evolving and Dr. Bawden has announced that the next NASA missions will be able to collect data with such a precision that has never seen before. For example, they will calculate the amount of plant biomass in a forest or the state of the health of cultivation, at anytime and anywhere in the world.
The Planet’s water cycle is changing
Planet Earth’s water has its own life: it evaporates from the oceans, creates the clouds, and becomes rain, then rivers and then returns to the sea and starts all over again. However, in recent years, the cycle has been subject to changes that have modified the rhythm and intensity. In this context, the satellite technologies have proven to be very useful to understanding the entity and nature of changes. In particular, in 2010, when a particular phenomenon occurred: “Thanks to the satellites we realised that, in that year, the global water cycle seemed as if interrupted - explained Dr. Bawden - because there was a strong increase in humidity in two areas of the planet, Australia and northern part of South America, but a large mass of water was missing in the oceans. The causes are still unknown but we are carrying out studies to better understand the phenomenon”.
