Travis Swaggerty, Melanie Wetzel and Dorothea Ivanova
1
Use of Research Aircraft Data to Validate Mesoscale Model Forecasts Travis Swaggerty, Melanie Wetzel and Dorothea Ivanova Department of Applied Aviation Sciences, College of Aviation, Embry-Riddle Aeronautical University, Prescott, AZ 2. Case Study Approach 5. Conclusions 1. Research Objective 3. Forecast Model Simulations Acknowledgements • Meteorological observations and modeling have been used to address the question: “Can a mesoscale model accurately predict frontal passage events that pose a risk to student pilots at ERAU?” • Pilot training operations based at the Embry-Riddle Prescott campus would benefit from forecasts of wind shear and other flight hazards • The Student Training in Airborne Research and Technology (START) program provided research aircraft measurements during a two-week field program in spring 2014 • Aircraft data analysis provides a valuable tool for verification of model case study simulations This research was supported by the National Science Foundation, the Embry- Riddle College of Aviation, the University of Wyoming King Air Facility, and the NASA/Arizona Space Grant program at Embry-Riddle. • The Advanced Research Weather Research and Forecasting mesoscale model (ARW-WRF), version 3.6.1, was implemented for a case study of 2 April 2014 • Aircraft cloud physics, thermodynamics and kinematics were obtained by the University of Wyoming instrumented King Air (UWKA) (Wetzel and Ivanova, 2014; Wetzel et al., 2015) • Features of the boundary layer thermodynamic profiles, such as wind or hydrometeors were simulated and compared with aircraft, radar, radiosonde and other forecast products • Inner domain centered over Prescott airport (KPRC) with a 10km horizontal grid resolution • Outer domain centered over southwestern U.S. with a 30km grid resolution • A convective parameterization was used with specification of entrainment (Weisman et al., 2008) • A Rapid Update Cycle (RUC) land-surface model was used for topographical features 4. Verification and Analysis 6. References Fig. 10. Temperature, dew point and wind barb vertical profiles obtained by ERAU radiosonde launch team. Fig. 8. Time series of air temperature (trf, deg C) and aircraft altitude (GALT, m MSL) during UW King Air flight. Fig. 2. UW King Air 3- dimensional flight track segment for case study, showing the multiple levels measured over the same flight track. Fig. 1. UW King Air flight track, 02 April 2014, tracks 10km apart and approximately 15km in length. Wind barbs obtained from instantaneous aircraft measurements. Fig. 5. 18hr forecast valid at 0000 UTC 03 Apr 14. Total cloud mixing ratio (g/kg) is shown at 700 mb. Wetzel, M.A., D. Ivanova, J. French, L. Oolman, and T. Drew, 2015: Educational deployment of a research aircraft for interdisciplinary education, 24th Symposium on Education, Annual Meeting of the American Meteorological Society, Phoenix, AZ, Amer. Meteor. Soc., 4-8 January 2015. Wetzel, M., and D. Ivanova, 2014: Campus-based Training in Airborne Atmospheric Research. Aviation, Aeronautics and Aerospace International Research Conference, Litchfield Park, AZ, 17-18 January 2014. Weisman, M., et al., 2008: Experiences with 0-36-h Explicit Convective Forecasts with the WRF-ARW Model. Weather and Forecasting, 23: 407-436 Fig. 3. 18hr forecast valid 0000 UTC 3 Apr 14. Air temperature ( o C, shaded), wind velocity (m/s, barbs) and geopotential height (m, contours) are shown at 500 mb. Fig. 4. 18hr forecast valid 0000 UTC 3 Apr 14. Air temperature ( o C, shaded), wind velocity (m/s, barbs) and geopotential height (m, contours) are shown at 700 mb. Fig. 11. Doppler Velocity (m/s) for KFSX radar at 22 UTC 2 Apr 14. Fig. 9. GALT, winds, wind direction plotted from UW King Air flight. Fig. 6. 18hr forecast valid at 0000 UTC 03 Apr 14. Total cloud mixing ratio (g/kg) is shown at 750 mb. Email: [email protected] • Model results shown (Fig. 3 – Fig. 6) depict wind fields and total cloud mixing ratio (condensed liquid and ice) for 00:00 UTC 3 Apr 14 • At both 500 mb and 700 mb the wind field is indicative of a sharp transition of the winds from SW to N associated with a frontal boundary. Vertical wind shear is also apparent in comparing the wind velocities at the two pressure levels. • The difference between the cloud mixing ratio field in (Fig. 5 and Fig. 6) suggest a cloud base above 750 mb • The linear characteristics of the NE to SW line (E Central Utah to NW Arizona) of total cloud mixing ratio in Fig. 5 provides evidence for the frontal boundary mentioned above • Fig. 8 presents the aircraft altitude and temperature conditions along aircraft transects ; temperatures at 5.5 km indicate agreement with predicted pattern in temperature at 500 mb (Fig. 3) • Along-track variation in wind velocity and direction (Fig. 9) matches the wind barbs shown in Fig. 3 (500 mb; approx. 5.5 km) and Fig. 4 (700 mb ; approx. 3.2 km) • The radiosonde launched from Embry-Riddle campus shows an inversion and shallow cloud layer above 750 mb, as predicted in the model (compare Fig. 5 and Fig. 6) • The Doppler Velocity radar scan (Fig. 11) indicates the area and movement of precipitation, which appears to be more widespread than in the model (Fig. 5). • Aircraft physical measurements demonstrate skill of the WRF model in predicting the temperature, wind and cloud field conditions during a frontal passage with significant wind shear • Additional validation research is ongoing, and will utilize the NWS dual-polarization radar data archive
Transcript of Travis Swaggerty, Melanie Wetzel and Dorothea Ivanova
Use of Research Aircraft Data to Validate Mesoscale Model Forecasts
Travis Swaggerty, Melanie Wetzel and Dorothea IvanovaDepartment of Applied Aviation Sciences, College of Aviation, Embry-Riddle Aeronautical University, Prescott, AZ
2. Case Study Approach
5. Conclusions
1. Research Objective 3. Forecast Model Simulations
Acknowledgements
• Meteorological observations and modeling have been used to address the question: “Can a mesoscale model accurately predict frontal passage events that pose a risk to student pilots at ERAU?”
• Pilot training operations based at the Embry-Riddle Prescott campus would benefit from forecasts of wind shear and other flight hazards
• The Student Training in Airborne Research and Technology (START) program provided research aircraft measurements during a two-week field program in spring 2014
• Aircraft data analysis provides a valuable tool for verification of model case study simulations
This research was supported by the National Science Foundation, the Embry-Riddle College of Aviation, the University of Wyoming King Air Facility, and the
NASA/Arizona Space Grant program at Embry-Riddle.
• The Advanced Research Weather Research and Forecasting mesoscale model (ARW-WRF), version 3.6.1, was implemented for a case study of 2 April 2014
• Aircraft cloud physics, thermodynamics and kinematics were obtained by the University of Wyoming instrumented King Air (UWKA) (Wetzel and Ivanova, 2014; Wetzel et al., 2015)
• Features of the boundary layer thermodynamic profiles, such as wind or hydrometeors were simulated and compared with aircraft, radar, radiosonde and other forecast products
• Inner domain centered over Prescott airport (KPRC) with a 10km horizontal grid resolution
• Outer domain centered over southwestern U.S. with a 30km grid resolution
• A convective parameterization was used with specification of entrainment (Weisman et al., 2008)
• A Rapid Update Cycle (RUC) land-surface model was used for topographical features
4. Verification and Analysis
6. References
Fig. 10. Temperature, dew point and wind barb vertical profiles obtained by ERAU radiosonde launch team.
Fig. 8. Time series of air temperature (trf, deg C) and aircraft altitude (GALT, m MSL) during UW King Air flight.
Fig. 2. UW King Air 3-dimensional flight track segment for case study, showing the multiple levels measured over the same flight track.
Fig. 1. UW King Air flight track, 02 April 2014, tracks 10km apart and approximately 15km in length. Wind barbs obtained from instantaneous aircraft measurements.
Fig. 5. 18hr forecast valid at 0000 UTC 03 Apr 14. Total cloud mixing ratio (g/kg) is shown at 700 mb.
Wetzel, M.A., D. Ivanova, J. French, L. Oolman, and T. Drew, 2015: Educational deployment of a research
aircraft for interdisciplinary education, 24th Symposium on Education, Annual Meeting of the American Meteorological
Society, Phoenix, AZ, Amer. Meteor. Soc., 4-8 January 2015.
Wetzel, M., and D. Ivanova, 2014: Campus-based Training in Airborne Atmospheric Research. Aviation,
Aeronautics and Aerospace International Research Conference, Litchfield Park, AZ, 17-18 January 2014.
Weisman, M., et al., 2008: Experiences with 0-36-h Explicit Convective Forecasts with the WRF-ARW Model.
Weather and Forecasting, 23: 407-436
Fig. 3. 18hr forecast valid 0000 UTC 3 Apr 14. Air temperature (oC, shaded), wind velocity (m/s, barbs) and geopotential height (m, contours) are shown at 500 mb.
Fig. 4. 18hr forecast valid 0000 UTC 3 Apr 14. Air temperature (oC, shaded), wind velocity (m/s, barbs) and geopotential height (m, contours) are shown at 700 mb.
Fig. 11. Doppler Velocity (m/s) for KFSX radar at 22 UTC 2 Apr 14.
Fig. 9. GALT, winds, wind direction plotted from UW King Air flight.
Fig. 6. 18hr forecast valid at 0000 UTC 03 Apr 14. Total cloud mixing ratio (g/kg) is shown at 750 mb.
Email: [email protected]
• Model results shown (Fig. 3 – Fig. 6) depict wind fields and total cloud mixing ratio (condensed liquid and ice) for 00:00 UTC 3 Apr 14
• At both 500 mb and 700 mb the wind field is indicative of a sharp transition of the winds from SW to N associated with a frontal boundary. Vertical wind shear is also apparent in comparing the wind velocities at the two pressure levels.
• The difference between the cloud mixing ratio field in (Fig. 5 and Fig. 6) suggest a cloud base above 750 mb
• The linear characteristics of the NE to SW line (E Central Utah to NW Arizona) of total cloud mixing ratio in Fig. 5 provides evidence for the frontal boundary mentioned above
• Fig. 8 presents the aircraft altitude and temperature conditions along aircraft transects ; temperatures at 5.5 km indicate agreement with predicted pattern in temperature at 500 mb (Fig. 3)
• Along-track variation in wind velocity and direction (Fig. 9) matches the wind barbs shown in Fig. 3 (500 mb; approx. 5.5 km) and Fig. 4 (700 mb ; approx. 3.2 km)
• The radiosonde launched from Embry-Riddle campus shows an inversion and shallow cloud layer above 750 mb, as predicted in the model (compare Fig. 5 and Fig. 6)
• The Doppler Velocity radar scan (Fig. 11) indicates the area and movement of precipitation, which appears to be more widespread than in the model (Fig. 5).
• Aircraft physical measurements demonstrate skill of the WRF model in predicting the temperature, wind and cloud field conditions during a frontal passage with significant wind shear
• Additional validation research is ongoing, and will utilize the NWS dual-polarization radar data archive
