1. Image Interpretation for Weather Analysis Part I 21 October 2010 Dr. Steve Decker

2. Two Kinds  Polar Orbiting –Polar-orbiting Operational Environmental Satellite (POES)  NOAA-19 (2009) [NOAA-18 and older provide backup]  MetOp-A (2006)  Two in operation at one time –Sun-synchronous - 2:30 and 7:30  To be replaced by NPOES in 2014  Geostationary –Geostationary Operational Environmental Satellite (GOES) –How does a geostationary orbit work?

3. Meet the GOES Satellites  GOES 11, 2000/2006, 135°W, 2 nd gen. –Current GOES-West  GOES 12, 2001/2003, 60°W, 2 nd gen. –Was GOES-East, now covering South America  GOES 13, 2006/2010, 75°W, 3 rd gen. –Current GOES-East  GOES 14, 2009, 3 rd gen.  GOES 15, 2010, 3 rd gen.  Fourth generation (GOES-R / GOES-NEXT) scheduled for launch in 2014

5. Meet the GOES Satellites  GOES 11, 2000/2006, 135°W, 2 nd gen. –Current GOES-West  GOES 12, 2001/2003, 60°W, 2 nd gen. –Was GOES-East, now covering South America  GOES 13, 2006/2010, 75°W, 3 rd gen. –Current GOES-East  GOES 14, 2009, 3 rd gen.  GOES 15, 2010, 3 rd gen.  Fourth generation (GOES-R / GOES-NEXT) scheduled for launch in 2014

7. Meet the GOES Satellites  GOES 11, 2000/2006, 135°W, 2 nd gen. –Current GOES-West  GOES 12, 2001/2003, 60°W, 2 nd gen. –Was GOES-East, now covering South America  GOES 13, 2006/2010, 75°W, 3 rd gen. –Current GOES-East  GOES 14, 2009, 3 rd gen.  GOES 15, 2010, 3 rd gen.  Fourth generation (GOES-R / GOES-NEXT) scheduled for launch in 2014

9. Improvement Example  Registration GOES-12 vs. GOES-13 Registration GOES-12 vs. GOES-13 Registration GOES-12 vs. GOES-13

10. GOES Image Frequency  Standard Operations –Every 30 minutes for CONUS –Every three hours for full disk (takes 26 minutes)  Rapid Scan Operations –Every 5 to 15 minutes for CONUS  Super Rapid Scan Operations –Every minute for small region –Example: Hurricane Frances Hurricane FrancesHurricane Frances

11. Common Channels  Visible –0.65 μm (red)  Infrared (IR) –10.7 μm  Water Vapor –6.7 μm  Shortwave IR –3.9 μm

12. Visible Channel  Measures amount of sunlight reflected –Approximates Earth’s albedo  Clouds –Thick: High albedo  White –Thin: Moderate albedo  Light or medium gray  Ocean: Low albedo  Black  Land: Variable albedo  Shades of gray

13. Sun Angle Effects  Brightness varies by time of day  “Terminator”: sunrise/sunset line  Cloud shadows –Bumpy cloud top  lumpy depiction –Flat cloud top  smooth depiction  Sunglint –Brighter  smoother sea

15. Sun Angle Effects  Brightness varies by time of day  “Terminator”: sunrise/sunset line  Cloud shadows –Bumpy cloud top  lumpy depiction –Flat cloud top  smooth depiction  Sunglint –Brighter  smoother sea

17. Infrared Channel  Amount of radiation received by satellite with λ=10.7 μm  Combination of surface and cloud-top temperatures  For monochrome images, colder temperatures are brighter –Why?  Snow vs low clouds vs land

18. IR Enhancement

24. Geographic Features  Background for the weather features  Coasts –Vis: Sudden change from dark (ocean) to light (land) –IR: At night, land is often colder (brighter) than water. Vice versa during daytime.  Lakes –Vis: Shows ice-cover (bright)

26. Geographic Features  Background for the weather features  Coasts –Vis: Sudden change from dark (ocean) to light (land) –IR: At night, land is often colder (brighter) than water. Vice versa during daytime.  Lakes –Vis: Shows ice-cover (bright)

29. Geographic Features  Background for the weather features  Coasts –Vis: Sudden change from dark (ocean) to light (land) –IR: At night, land is often colder (brighter) than water. Vice versa during daytime.  Lakes –Vis: Shows ice-cover (bright)

30. Another Example

32. Geographic Features  Land type –Wooded  Darker on Vis –Sandy; little vegetation  Brighter on Vis  Heat islands –Dark spots in IR at night  Snow –Vis: Distinguishable from clouds in animations –Vis: Brighter in treeless areas

34. Geographic Features  Land type –Wooded  Darker on Vis –Sandy; little vegetation  Brighter on Vis  Heat islands –Dark spots in IR at night  Snow –Vis: Distinguishable from clouds in animations –Vis: Brighter in treeless areas

36. Geographic Features  Land type –Wooded  Darker on Vis –Sandy; little vegetation  Brighter on Vis  Heat islands –Dark spots in IR at night  Snow –Vis: Distinguishable from clouds in animations –Vis: Brighter in treeless areas

38. Cloud Patterns  Cloud shield –Broad pattern with similar width in any direction  Cloud band –Continuous formation with a distinct long axis  Cloud line –Narrow cloud band (less than 60 n mi wide)  Cloud street –Narrow cloud band with distinct elements –Often come closely packed in parallel  Cloud element –Smallest resolvable cloud in imagery  Comma cloud –Spiraling cloud with at least one band, often shaped like a comma

40. Cloud Streets

41. Cloud Identification  Compare visible and infrared images  Brightness –Height and thickness  Texture –Visible only; shadows  Pattern  Edge definition  Size  Shape

42. Identifying Stratiform Clouds  Stratus –Smooth, flat tops; low altitude –IR: Difficult to see –Vis: Often quite bright  Altostratus  Fog –Difficult to distinguish from stratus using Vis and IR –Motionless; evaporates from outside in –Valley fog

45. Identifying Stratiform Clouds  Stratus –Smooth, flat tops; low altitude –IR: Difficult to see –Vis: Often quite bright  Altostratus  Fog –Difficult to distinguish from stratus using Vis and IR –Motionless; evaporates from outside in –Valley fog

48. Identifying Cumuliform Clouds  Cumulus –Vis: Medium bright; lumpy –IR: Dark to medium gray; hard to see individual elements

52. Identifying Cumuliform Clouds  Cumulus –Vis: Medium bright; lumpy –IR: Dark to medium gray; hard to see individual elements  Stratocumulus –Vis: Bright; often cellular –IR: Dark; can be hard to detect

54. Identifying Cumuliform Clouds  Cumulus –Vis: Medium bright; lumpy –IR: Dark to medium gray; hard to see individual elements  Stratocumulus –Vis: Bright; often cellular –IR: Dark; can be hard to detect  Cumulonimbus –Very bright in both Vis and IR

57. Identifying Cirriform Clouds  Cirrus –Vis: Dark/medium gray; wispy; thin –IR: Light gray; not as fibrous

60. Identifying Cirriform Clouds  Cirrus –Vis: Dark/medium gray; wispy; thin –IR: Light gray; not as fibrous  Cirrostratus –Vis: Smooth; light gray; thicker –IR: Light gray to white

64. Identifying Cirriform Clouds  Cirrus –Vis: Dark/medium gray; wispy; thin –IR: Light gray; not as fibrous  Cirrostratus –Vis: Smooth; light gray; thicker –IR: Light gray to white  Cirrocumulus

66. Identifying Cirriform Clouds  Cirrus –Vis: Dark/medium gray; wispy; thin –IR: Light gray; not as fibrous  Cirrostratus –Vis: Smooth; light gray; thicker –IR: Light gray to white  Cirrocumulus  Anvil Cirrus