资讯

NASA28 天
Image of the Day - NASA Earth Observatory
The Earth Observatory shares images and stories about the environment, Earth systems, and climate that emerge from NASA research, satellite missions, and models.
NASA10 年
The Water Cycle - NASA Earth Observatory
The water, or hydrologic, cycle describes the pilgrimage of water as water molecules make their way from the Earth’s surface to the atmosphere and back again, in some cases to below the surface. This ...
NASA13 年
Climate and Earth’s Energy Budget - NASA Earth Observatory
Earth’s temperature depends on how much sunlight the land, oceans, and atmosphere absorb, and how much heat the planet radiates back to space. This fact sheet describes the net flow of energy through ...
NASA13 年
Seeing Forests for the Trees and the Carbon: Mapping the World’s Forests in Three Dimensions
Sassan Saatchi, a remote sensing scientist at NASA’s Jet Propulsion Laboratory, is one of several collaborators and friendly competitors working on that next draft of forest maps. He is working with ...
NASA1 年
Earth Observatory On This Day
The Earth Observatory shares images and stories about the environment, Earth systems, and climate that emerge from NASA research, satellite missions, and models.
NASA13 年
Monitoring Sea Ice - NASA Earth Observatory
Dating back to A.D. 870, intermittent records assembled by the Vikings record the number of weeks per year that ice occurred along the north coast of Iceland. Other, scattered records of Arctic sea ...
NASA8 年
A Delicate Balance: Signs of Change in the Tropics - NASA Earth Observatory
While NASA climate scientists were reviewing radiation data emanating from the tropics simply to test existing notions, they uncovered a phenomenon no one expected. They found that progressively more ...
NASA8 年
Defining Desertification - NASA Earth Observatory
A string of dry years shriveled vegetation in Africa's Sahel, causing some to fear that the Sahara Desert was shifting south. Satellite data spanning more than twenty years now shows that the Sahel is ...
NASA15 年
Global Warming - NASA Earth Observatory
Global Warming. Throughout its long history, Earth has warmed and cooled time and again. Climate has changed when the planet received more or less sunlight due to subtle shifts in its orbit, as the ...
NASA14 年
The Carbon Cycle - NASA Earth Observatory
Carbon flows between the atmosphere, land, and ocean in a cycle that encompasses nearly all life and sets the thermostat for Earth's climate. By burning fossil fuels, people are changing the carbon ...
NASA8月
Elegant Figures - How To Make a True-Color Landsat 8 Image - NASA Earth Observatory
Since its launch in February 2013, Landsat 8 has collected about 400 scenes of the Earth’s surface per day. Each of these scenes covers an area of about 185 by 185 kilometers (115 by 115 miles)—34,200 ...