What is CALIPSO Mission?

About CALIPSO Mission

• CALIPSO (Cloud-Aerosol LIDAR and Infrared Pathfinder Satellite Observations) is a mission dedicated to studying how clouds and aerosols impact the Earth’s climate. 
• It is a joint project between NASA (National Aeronautics and Space Administration) and CNES (Centre National d'Études Spatiales), the French space agency.
• Launched in 2006, CALIPSO is a satellite-based observatory.
• Scientists are using data from CALIPSO to construct 3D models of the atmosphere that improve our ability to predict future climate change. 
• CALIPSO has been part of a constellation of spacecraft called the "A-Train," including Aqua, Aura, and PARASOL spacecraft, dedicated to studying the Earth’s weather and environment.
• Instrumentation:
  • It carries CALIOP, a two-wavelength, polarization-sensitive lidar, along with two passive sensors operating in the visible and thermal infrared spectral regions.
  • The lidar emitted pulses of laser light and measured the amount of light that was scattered back by clouds and aerosols. This information was used to create vertical profiles of cloud and aerosol properties, such as their height, thickness, and optical depth.
  • CALIOP is the first lidar to provide long-term atmospheric measurements from Earth's orbit.
  • This information helps scientists create three-dimensional profiles of cloud and aerosol distributions.
  • The mission recorded more than 10 billion LIDAR measurements and helped create thousands of scientific reports over its 17 years of operation. 

Q1) What are aerosols?

Aerosols are tiny particles or droplets suspended in the air or another gas. They can be solid or liquid and vary in size from microscopic (nanometers) to larger particles that can be seen with the naked eye. Aerosols are ubiquitous in the Earth's atmosphere and can originate from natural sources as well as human activities. 

Source: NASA’s CALIPSO mission stops blasting lasers at Earth after 17 years