satellite monitoring of environmental change

• What is the primary method of observing the Earth mentioned in the material?

  From above
• What are two types of aerial vehicles used for Earth observation?

  Aircraft and UAV
• What is one type of satellite mentioned for Earth observation?

  NOAA GOES-E
• What does Earth observation involve?

  Gathering information about the physical world by detecting radiation reflected or emitted from it
• What is the temperature of the Sun's emissions mentioned in the material?

  6000K
• What is the wavelength range of visible light?

  0.4 - 0.7 μm
• At what wavelength does Earth peak emission occur?

  About 10 μm
• What is the wavelength range for UV radiation in the stratosphere?

  10 nm - 400 nm
• What are the wavelength ranges for vegetation in VIS and NIR?

  400 nm - 1400 nm
• What is the wavelength range for thermal infrared radiation?

  3 - 15 μm
• Why do satellites make images at multiple wavebands?

  For different applications
• What does ECV stand for in the context of climate observation?

  Essential Climate Variables
• How much carbon does vegetation take up annually through photosynthesis?

  Approximately 120 Pg per year
• How does the carbon uptake by land photosynthesis compare to human emissions?

  It is 15 times human emissions
• What are some processes that lead to the loss of carbon?

  Fire, land use change, respiration, and decomposition
• What does a healthy leaf indicate in terms of spectral signature?

  More absorption in visible light and higher reflection in NIR
• What is the formula for the Normalized Difference Vegetation Index (NDVI)?

  NDVI = (cnir - cvis) / (cnir + cvis)
• What is the NDVI value for a desert with cvis = 0.35 and cnir = 0.35?


  0
• What is the NDVI value for a temperate forest in summer with cvis = 0.05 and cnir = 0.35?

  0.75
• What does the NDVI indicate when calculated globally?

  It is proportional to light absorption by chlorophyll
• What are satellite datasets of light absorption and temperature used for?

  To model vegetation growth (Net Primary Productivity)
• How does emitted light change with temperature?

  It increases with temperature
• At what wavelengths can fire be detected?

  ~3-4 μm and ~10-12 μm
• What can satellites detect changes in due to fire?

  Temperature
• What is the accuracy of surface temperature measurements from satellites?

  Less than 0.2K
• How do aerosols affect the planet's temperature?

  They cool the planet by scattering light
• Why is it easier to detect aerosols over oceans or dark surfaces?

  Because they are more easily detected in those areas
• What is Aerosol Optical Depth (AOD) used for?

  For climate and air quality
• How is CO2 detected using satellite technology?

  Using Near IR absorption
• What can be combined with satellite measurements to enhance CO2 detection?

  Atmospheric models (assimilation)