1. Short Course on Satellite Meteorology 11 January 1998 Phoenix, Arizona Applications and Interpretation: Part 3 - Sounder Products and Applications Donald G. Gray NOAA/NESDIS Office of Research and Applications Washington, DC AMS 78th Annual Meeting

2. Presentation Outline I. Brief review of remote sensing fundamentals, including absorption spectra and weighting functions II. Characteristics of GOES soundings ( spatial coverage, production methodology, derived parameters) and validation) III. Applications of GOES sounding products to weather analysis and forecasting.

3. Absorption Spectra Transmittances, Weighting Functions Examples of GOES Sounder Channels Remote Sensing Fundamentals - Satellite Soundings Longwave CO2 Mid-wave H2O Shortwave CO2 Visible

4. Characteristics of GOES Satellite Soundings Spatial Coverage, Frequency Resolution, Effects of Clouds Use of NWP Model Forecast (ETA) Production Methodology Radiosonde Comparison Statistics ETA Forecast Model Impact Study Quality Assessment

5. Applications/Examples of GOES Sounding Products Nowcasting/Forecasting of Severe Weather Horizontal Fields of Derived Products Individual Soundings and Associated Parameters Derived Product Images Gradient Winds Sounder Water Vapor Winds Effective Cloud Amount and Cloud Top Pressure

6. Summary GOES Soundings Provide 24 Hour High Resolution Coverage for CONUS and Adjacent Ocean Areas Horizontal Resolution of ~50KM (~30KM Currently in Experimental Mode) Provide Information on Mesoscale Features of Moisture and Stability in Pre-Convective Environments Case Studies Indicate Strong Correlation Between GOES Soundings’ Fields and Convective Development Other Applications: Depiction of Moisture: Eastern Pacific, Gulf of Mexico Return Flow, Southwest Monsoons, East Coast Winter Storms Positive impact demonstrated using GOES TPW in ETA Forecast Model

7. Summary (cont’d) Limitations : Coarse vertical resolution (~3 - 4 km) Soundings Precluded in Cloudy Areas Geographic Coverage Limited by Slow Scan Rate Retrieval of Boundary Layer T/Td Not Possible

8. http://orbit7i.nesdis.noaa.gov:8080/temp.html Acknowledgments Tim Schmit, Tony Schreiner, CIMSS, University of Wisconsin Bill Smith, Kit Hayden and Paul Menzel Jaime Daniels (NOAA), Gary Gray (Raytheon/Hughes) Web Addresses (NOAA/NESDIS/ORA) http://orbit7i.nesdis.noaa.gov:8080/goes.html GOES Sounder Products Other GOES Quantitative Products http://orbit7i.nesdis.noaa.gov:8080/index.html POES/GOES Satellite Products

9. Resolution and Effects of Clouds GOES Sounder Field of View (FOV) - 10 km at nadir Sounder Radiances Processed Using Arrays 5x5 FOV’s - Operational 3x3 FOV’s - Experimental Individual FOV’s Screened for Clouds Clouds Act as a Radiating Surface, Contaminate IR Measurements Cloud-Free Sounder FOV’s Used to Generate Sounding 9 - 25 Clear FOV’s Required - Operational 1 - 9 Clear FOV’s Required - Experimental

10. GOES-9 Total Precipitable Water (mm) Tan: 0 - 9 mm Yellow: 10 - 19 mm Green: 20 - 29 mm 8 JAN 1998 1500 GMT

11. Regional Display - GOES-9 TPW (mm) Phoenix, AZ

12. Central and Eastern Kansas, July 13-14, 1997 GOES Visible Movie Loop Severe Weather Reports Precipitable Water and Lifted Index Fields ETA Forecast GOES Soundings Time Tendency Analyses ETA Precipitation Forecast

13. GOES-8 Visible Imagery 1915Z 7/13/97 - 0115Z 7/14/97

14. Severe Weather Reports: 23Z 7/13/97 - 05Z 7/14/97

15. ETA 00-12 Hour Precip Forecast (mm) Valid 00Z 7/14/97 GOES-8 Visible Image 00Z 7/14/97

16. ETA Forecast TPW 18Z-00Z 7/13/97 (2 Hour Intervals)

17. GOES TPW 18Z-00Z 7/13/97 (2 Hour Intervals)

18. ETA Forecast LI 18Z - 00Z 7/13/97 (2 Hour Intervals)

19. GOES LI 18Z - 00Z, 7/13/97 (2 Hour Intervals)

20. ETA/GOES 4 Hour Time Tendency (LI) 18Z-22Z

21. ETA/GOES 4 Hour Time Tendency (TPW) 18Z - 22Z Back to AWIPS

22. Spatial Coverage/Frequency: GOES Soundings Scan cycle : One Hour Two scans each - GOES-8 and GOES-9 GOES-8: 35 Minutes - Eastern CONUS 20 Minutes - Selectable Atlantic Sector GOES-9: 20 Minutes - Western CONUS 35 Minutes - Pacific Sector No Southern Hemisphere Coverage at this Time

23. Composite GOES-8/9 Hourly Sounder Coverage 9 9 8 8A 8B 8C

24. Absorption Spectra - Infrared Sounders Primary absorbing atmospheric constituents: o Carbon Dioxide Longwave: 11 - 18 microns (Surface/ Atmospheric Temperature) Shortwave: 4 - 6 microns (Surface/Lower Atmospheric Temperature) o Water Vapor Midwave: 6 - 10 microns (Atmospheric Moisture) o Ozone 9.6 microns: (Total Column Atmospheric Ozone)

26. GOES-8/9 Sounder - Channel 8

28. GOES-8/9 Sounder - Channel 7

29. GOES-8/9 Sounder - Channel 6

30. GOES-8/9 Sounder - Channel 5

31. GOES-8/9 Sounder - Channel 4

32. GOES-8/9 Sounder - Channel 3

33. GOES-8/9 Sounder - Channel 2

34. GOES-8/9 Sounder - Channel 1

35. GOES-8/9 Sounder Channel 11 (Water Vapor)

36. Return to COMET AWIPS presentation

37. Transmittances and Weighting Functions Transmittance: Percent of radiation of particular wavelength transmitted through atmosphere. Transmittance = 1 - Emmisivity Weighting Function: Derivative of transmittance with respect to height (lnP). Larger values correspond to atmospheric layers with the greatest contribution to radiance values.

38. Example: GOES-8 Transmittances for 3 Longwave Channels

39. Weighting Functions for GOES Longwave Channels

40. Weighting Functions for GOES Midwave Channels

41. Weighting Functions for GOES Shortwave Channels

42. ETA Forecast Used as Initial Conditions for Sounding Forecast Temperature and Moisture Profiles Interpolated to GOES Sounding Location and Time 00Z06Z12Z18Z00Z 12Z ETA 12,18hr Fcst 00Z ETA 06,12hr Fcst 00Z ETA 12,18hr Fcst 12Z ETA 06,12hr Fcst Sounder Radiances Computed from ETA Forecast Observed Radiances Corrected for Bias Relative to Forecast Differences Between Computed and Observed Radiances Used to Modify Initial ETA Profile Adjustments Made Primarily to Moisture Profile

43. GOES-9 Sounding - Phoenix, AZ 6 JAN 98 15 GMT Little Modification to Initial ETA T/Td Forecast

44. GOES-8 Sounding - Gainesville, FL 6 JAN 98 15 GMT Significant Modification to Initial ETA Td Forecast

45. GOES-8/9 Brightness Temperature Differences GOES Observed BT’s - ETA Computed BT’s Larger differences are observed in Gainesville sounding, particularly in channels sensitive to atmospheric moisture

46. Colocation Statistics - Total Precipitable Water (mm) Radiosondes vs. ETA Forecast and GOES Soundings Root Mean Square Error

47. ETA Model Impact Study (NCEP) August 1997 Equitable Threat Score - Precipitation

49. Phoenix, Arizona 6 Jan 98 20 GMT - 7 Jan 98 19GMT

51. GOES-8 500mb Gradient Winds - Montserrat

52. GOES-8 Derived Product Image - TPW (mm) 6 Jan 98 21 GMT