1. Atmospheric Applications of Multi- and Hyperspectral Remote Sensing
Climate, Meteorology and Atmospheric Chemistry

3. Learning Objectives
Understand the advantages of different orbital patterns for meteorology.
What are the primary uses for visible vs. thermal RS in meteorology?
In general terms, how do we estimate atmospheric constituents with RS data?
What is the difference between tropospheric and stratospheric ozone?

4. Applications of satellites for atmospheric studies
Weather monitoring and forecasting
Cloud type identification
Active RS (e.g., radar)
Atmospheric Composition
Atmospheric chemistry
Pollution monitoring
Aerosols
Volcanic ash
Climate studies
Atmospheric role in climate
Land-atmosphere interactions
Ocean-atmosphere interactions

5. Von Karman Vortices
Named after Theodore von Karman. Caused by unsteady fluid flow around blunt objects (like islands in this image).

6. Hurricane Fran, 1996

7. MODIS Image
Saharan dust moving across Mediterranean to Turkey

8. Sulfur Dioxide Plume – Kahlua

9. Meteorological RS: Early History (Review)
Earliest man-made satellites were designed for weather observations
Vanguard 2 (1959) – designed to measure cloud cover but didn’t work well
TIROS 1 (1960) – crude weather observations allowed scientists to view earth’s weather as a system
Application Technology Satellites (1966) – full disk view of earth
Nimbus satellites (1964 – 78) – atmospheric temperature and ozone profiles and other atmospheric properties

11. Types of weather satellites
Defined by orbital characteristics
Polar orbiting – travel roughly over poles on each orbit
Typically two views/day of each place on earth
Relatively high spatial resolution due to lower altitude than geostationary
Geostationary – orbit parallel to the equator at an altitude of 22,300 miles; always over one place.
Full hemisphere or large area viewing but usually at lower resolution due to altitude

12. Modern weather satellites
GOES – Geostationary Operational Environmental Satellites
GOES 13 also called GOES East – over Brazil but captures imagery for our entire hemisphere
GOES 15 also called GOES West – over eastern Pacific Ocean
GOES 16 launched in November 2016
NOAA operates several polar orbiting weather satellites (NPOES)
Many other countries have their own weather satellites that are either polar orbiting and geostationary

13. GOES 16
As of early March, still undergoing testing before being declared operational.
Improvements over previous GOES include:
Higher spatial and spectral resolution
Lightning monitoring in real time
Better water vapor sensing
Geomagnetic storm forecasts
Solar flare monitoring

14. GOES 16 1-hour cumulative lightning optical emission
GOES 16 1-hour cumulative lightning optical emission. GOES can monitor lightning continuously. (NOAA image)

16. Spring snowstorm in Wyoming (April 15, 2016)
GOES Composite Image of US
Warm (low) clouds bluish, Cold (high) clouds yellow and red.
Spring snowstorm in Wyoming (April 15, 2016)

17. GOES West Image
Thermal IR
Full Disk
April 6, 2015

18. GOES East full disk
Visible
April 6, 2015

19. How are weather satellites used?
Interpretation of visible (panchromatic) images
Cloud and aerosol thicknesses
Interpretation of infrared images
Cloud temperatures and heights
Prognostication (prediction)
Time-lapse views that show movement of systems
Hurricane tracking and monitoring
Data inputs for weather models

20. Visible wavelength satellite imagery
Can see clouds (bright) and relative cloud thickness (brighter = thicker until saturation)
Can see haze and aerosol (relatively bright)
Cannot distinguish cloud heights (low, middle and high altitude clouds all look the same)
Visible can only be used in the daytime
Image from April 15, 2016

21. IR satellite imagery
Long-wave IR (thermal) allows sensing of the temperature of the cloud tops--related to height
Higher cloud tops colder than low cloud tops
IR Weather images are processed so that coldest places appear BRIGHT and warmest appear DARK
Opposite of normal thermal imagery!!
Can be used day or night.

22. Water vapor images
IR Satellite imagery can also be used to create images of the amount of water vapor in the atmosphere

24. Remote sensing for monitoring atmospheric constituents
Several satellites have bands that are used for atmospheric chemistry (e.g., MODIS) or are completely dedicated to the atmosphere (e.g., AURA)
Aura flies “in formation” about 15 minutes behind MODIS
Aura carries several instruments that measure the concentration of atmospheric constituents
Other satellites
TOMS – Total Ozone Mapping Spectrometer
UARS – Upper Atmosphere Research Satellite
AURA: NO2, ozone, sulfur dioxide, etc.

25. Human activities have changed the composition of the atmosphere since the pre- industrial era
Some sulfate is natural (e.g., volcanoes), but some is anthropogenic (e.g. from burning coal).

27. Photo by Mark Gocke, Casper Star Tribune.

28. Ground based sensors
Note: Ground based sensors are used more than satellite sensors for atmospheric chemistry (and pollution)
Can look outwards just as a satellite looks downwards and measure amount of light in various wavelengths
Atmospheric absorption of particular wavelengths indicative of particular chemicals
Strength of absorption relates to concentration of chemical
Value of space based sensors is more in getting whole- atmosphere view; Ground based sensors limited spatially

29. Air pollution monitoring with satellites
Satellites can measure and track plumes of air pollution
E.g., MOPITT – Measurements Of Pollution In The Troposphere
Measures amount of carbon monoxide and methane in the atmosphere
On same satellite as MODIS
Many satellites for atmospheric chemistry can also measure some pollutants

30. Global carbon monoxide during MOPITT’s first year of operation
CO produced by burning of fossil fuels, biomass, volcanoes, wildfire, etc.

31. Summary
Satellites are critical for weather forecasting and climate studies
Optical data primarily used for cloud studies
Thermal IR data also extremely useful (will discuss thermal later in semester)
Atmospheric scientists use satellites for global and local monitoring
Atmospheric pollution is a subset of atmospheric chemistry
Satellites allow mapping of general pattern of pollutant concentration and tracking of plumes, etc.