Update Dec.19 2014
The first image was released showing the carbon dioxide levels measured by OCO-2. High values are in orange and red. Much of that appears from burning of biomass according to this release from NASA.
The Orbiting Carbon Observatory-2 was launched early July 2, 2014. This night-time long exposure from Vandenberg Air Force Base in California is interesting. Its mission is to monitor the carbon dioxide (CO2) in the atmosphere to better understand the sources of it and where it goes. The greenhouse gas is part of a natural carbon cycle that is depicted in the graphic below. The sources of CO2 from human activity has increased steadily. Levels in the atmosphere are at an all time high of >400 ppm and rising. The OCO-2 spacecraft will help us understand and plan more effective measures to deal with this problem in the future.
The Carbon Cycle
Carbon is found naturally is five main reservoirs. They include the atmosphere, the biosphere of surface plants and animals, dead and alive, along with the soil, the oceans, the sediments of the oceans, and lastly the mantle and crust of Earth. These natural reservoirs don’t include human influences. Carbon is exchanged between the oceans, sediments, atmosphere, and biosphere in natural processes that maintained a steady state balance over the eons of time. Since humans have been burning large amounts of fossil fuels, that has resulted in a buildup of carbon in the atmosphere. It is unable to be transported to other reservoirs. As a result, the atmosphere is trapping heat from the Sun and raising the temperatures world wide. We are seeing the phenomenon of global warming and resulting changes in climate patterns.
The field of view of the OCO-2 instrument is about the size of Central Park in New York City, or 3 square kilometers. The view needs to be small in order to avoid clouds in the view. They compromise the data returns. The best carbon dioxide observations via satellite now take 4 seconds to make one reading. That is fewer than 20,000 pieces of data per day. Only about 500 of those are highly useful. OCO-2 will collect 24 readings every second for about 1 million a day. About 100,000 of those will be highly useful.
The A-Train Group
The OCA-2 spacecraft joins a group called a satellite constellation. This constellation is called the Afternoon Train, or A-Train. They follow one another in polar orbit passing over the same locations within seconds of each other. Their nearly simultaneous data collection assures that atmospheric conditions have not changed for the ensemble of data. Their altitude and grouping allows for an equator crossing at about 1:30 pm each day and 1:30 am each night in addition to their others about 90 minutes apart.
The two year mission, which could be extended, will yield much valuable information about the CO2 sources and sinks around the world. Accuracy will be increased by about 10x. Currently, the globe has about 100 monitoring stations for CO2. Many areas have none. This spacecraft will have global coverage in high resolution.
Models will be improved describing the carbon content and transport around the world. These improvements will allow scientists to make better forecasts and predictions about global climate change.