Science of Aerosols and Precipitation

Aerosols and clouds play a key role in climate.

• Clouds are brighter in when the droplets condense in the presence of aerosols. This is known as the Toomey effect and makes ship tracks visible from space.
• Aerosols can also suppress cloud formation by absorbing solar radiation and heating the atmosphere.
• There is growing evidence that aerosols can reduce precipitation by making cloud drops smaller so they coagulate slower

The ACE payload is design to provide much more information on aerosol-cloud interaction than any previous NASA mission.

To measure aerosols and clouds, ACE must have instruments operating from the visible through the infrared into the microwave. The visible light is affected by clouds, the infrared radiation tells the temperature of the clouds and the microwave measures cloud droplets. The ACE mission payload will include a radar and a lidar as well as passive imagers.

Science of Ocean Ecosystems

Ocean ecosystems are sensitive to changes in temperature and available nutrients such as iron rich dust. As climate changes, the ocean evosystems are expected to respond. ACE measurements of water leaving light can be used to characterize the phytoplankton content as well and the dissolved organic matter.

Four key science questions requiring ACE observations:

• How are ocean ecosystems and the biodiversity they support influenced by climate and environmental variability and change, and how will these changes occur over time?
• How do carbon and other elements transition between ocean pools and pass through the Earth System, and how do biogeochemical fluxes impact the ocean and Earth\'s climate over time?
• How (and why) is the diversity and geographical distribution of coastal marine habitats changing, and what are the implications for the well-being of human society?
• How do hazards and pollutants impact the hydrography and biology of the coastal zone? How do they affect us, and can we mitigate their effects?