1. Methodology n Step 1: Identify MOG (EDR ≥ 0.25) observations at cruising altitude (≥ FL250). n Step 2: Account for ascending/descending flights by filtering out those with an altitude change of 333 ft/min. n Step 3: Identify events which occurred within +/- 15 mins and in the field-of-view of a Aqua or Terra MODIS scan. n Step 4: Correct EDR observations for parallax to better match satellite signatures n Step 5: Display IR, WV, and Visible imagery using McIDAS, overlaying and centering the intensity-rated EDR reports. n Step 6: Analyze each event and sort by phenomena associated with turbulence; mountain or gravity waves, transverse banding, shear zones, convection, etc. Cases Satellite Observed Signatures Associated With Moderate to Severe Turbulence Events 2013 NOAA Satellite Conference, College Park, MD Figure 2. MOG turbulence associated with convection; robust cores and developing cells. Introduction Moderate or greater (MOG) turbulence is one of the biggest weather related causes of aviation incidents. However given the subjective nature of Pilot Reports (PIREPs), identifying exactly where the turbulence actaully occurred and which phenomena may be responsible is a challenge. For this reason, several airlines have begun to use onboard equipment on various 737s and 757s to record information that can be used to infer the presence of turbulence is-situ. One such measurement is the calculation of Eddy Dissipation Rate (EDR), which provides valuable in-situ data regarding the nature and location of turbulence, and is based on the ‘sea state’ of the atmosphere rather than aircraft response Purpose Using the EDR data, specifically MOG observations, in conjunction with satellite imagery from the Moderate-resolution Imaging Spectro-radiometer (MODIS), allows for a more detailed study of turbulence and associated weather phenomena and highlights the benefit of higher spatial resolution satellite imagery that will be provided by GOES-R ABI. An overview of MOG EDR reports from 2010 – 2011 Delta Airlines flights and the associated satellite signatures observed by MODIS imagery are detailed in the following sections. References Bedka, K., J. Brunner, R. Dworak, W. Feltz, J. Otkin, T. Greenwald, 2010: Objective Satellite-Based Detection of Overshooting Tops Using Infrared Window Channel Brightness Temperature Gradients. J. Appl. Meteor. Climatol., 49, 181–202. Lenz, A., K. M. Bedka, W. F. Feltz, S. A. Ackerman, 2009: Convectively Induced Transverse Band Signatures in Satellite Imagery. Wea. Forecasting, 24, 1362–1373. Feltz, W. F., K. M. Bedka, J. A. Otkin, T. Greenwald, S. A. Ackerman, 2009: Understanding Satellite-Observed Mountain-Wave Signatures Using High-Resolution Numerical Model Data. Wea. Forecasting, 24, 76–86. Uhlenbrock, N. L., K. M. Bedka, W. F. Feltz, S. A. Ackerman, 2007: Mountain Wave Signatures in MODIS 6.7-μm Imagery and Their Relation to Pilot Reports of Turbulence. Wea. Forecasting, 22, 662–670. Conclusions Gravity waves or mountain waves, transverse banding, and shear zones (WV gradients) were the most prominent satellite signatures associated with MOG turbulence events. Features associated with intense convection, such as overshooting tops, are easily identified via visible imagery and generally avoided by aircraft. Thus there were very few MOG reports within robust convective cores. A number of cases showed MOG turbulence within developing convection. These cases were likely due to aircraft encountering the updraft within the developing convective cloud. There were a number of cases that showed no unique satellite signature, indicating other atmospheric conditions not seen from satellite as the cause. In these cases, NWP model fields must also be used. 2010 – 2011 EDR Statistics Figure 1. MOG turbulence associated with gravity waves, mountain waves, and transverse banding. 0.25 > EDR < 0.35 0.35 >= EDR <.45 EDR >=.45 0.25 > EDR < 0.35 0.35 >= EDR <.45 EDR >=.45 Main Phenomena Gravity or Mountain Waves Transverse Banding Convection – robust or developing cores Broad precipitation but no obvious IR or visible satellite feature Clear Air Turbulence Bad image (error or off MODIS swath Summary of EDR cases and associated phenomena a) Gravity waves in convective outflow b) Transverse banding along a jet axis c) Banded precipitation structures d) Mountain waves a) Robust convective core b) Developing convection Figure 3. MOG associated with a water vapor gradient, or shear zone. GOES-13 IR Window GOES-13 Visible GOES-13 Water Vapor MODIS IR WindowMODIS Visible MODIS IR WindowMODIS Visible