Earth and Sky【24】

NASA's latest and most ambitious weather satellite is measuring Earth's water cycle. Learn more about the Aqua satellite —— today on Earth and Sky.

　　DB: I'm Deborah Byrd.

　　JB: And I'm Joel Block for Earth and Sky. This spring NASA launched a satellite called Aqua. Its mission is to measure the Earth's hydrological cycle —— the cycle water makes as it travels from the atmosphere, to land, to sea, and back again.

　　DB: Onboard satellite Aqua is a temperature sensing instrument called AIRS. It helps track the incredible journey of water vapor, going from the ocean surface to altitudes of nearly 32 kilometers, or about 20 miles. We spoke with Moustafa Chahine, Science Team Leader of the AIRS instrument, about the crucial role of water in Earth's climate.

　　Moustafa Chahine: Water vapor is the most active greenhouse gas we have, and therefore it has a lot to do with radiation. And water vapor ——when it rains in the form of precipitation —— redistributes the energy in our atmosphere and creates our weather…… Today we have about such 4,000 measurements daily, made mostly over land. AIRS will give us the equivalent of 400,000 measurements per day, covering not only land, but covering 70 percent of the Earth which is oceans.

　　JB: Chahine says this tremendous boost of information will greatly improve weather forecasting. And it might give climatologists the information they need to understand Earth's changing climate. More —— tomorrow. Special thanks today to NASA's Earth Science Enterprise. We're Block and Byrd for Earth and Sky.