Derived Motion Winds Scott Bachmeier Scott Lindstrom Cooperative

Derived Motion Winds Scott Bachmeier, Scott Lindstrom Cooperative Institute for Meteorological Satellite Studies (CIMSS) University of Wisconsin - Madison Contributors: Jaime Daniels (NOAA/NESDIS/STAR) Steve Wanzong, Dave Stettner, Chris Velden (CIMSS) June 2016

Lesson Objectives • How Derived Motion Winds (also known as Atmospheric Motion Vectors) are created • Height assignment of Derived Motion Winds • Validation, accuracy and precision of DMW • Uses and examples of Derived Motion Winds

n Derived Motion Winds Algorithm • Uses a set of 3 sequential images to estimate atmospheric motion • Follows sets of algorithm-identified tracers or “targets” (Visible/Infrared/Water Vapor cloud edges, or clearsky Water Vapor gradients) • DMW are calculated using 6 ABI bands: – Band 2 (Visible, 0. 64 µm) – Band 7 (Shortwave Infrared, 3. 9 µm) – Band 9 (Upper-level Water Vapor, 6. 2 µm) – Band 10 (Mid-level Water Vapor, 6. 9 µm) – Band 11 (Lower-level Water Vapor, 7. 3 µm) – Band 14 (Longwave Infrared, 11. 2 µm) • Coverage area (time interval): Full disk (60 minutes), CONUS (15 minutes), Mesoscale (5 minutes) • AHI data are used in this training as an excellent proxy for ABI data

Derived Motion Winds Algorithm A “nested tracking” technique is used for Visible, Infrared, and cloudy Water Vapor images • Using an image triplet, each Nx. N (size can vary) Target Scene is searched, both backward and forward in time • A cluster analysis program is then used to derive the “Dominant motion vector” for that entire Target Scene • A height value is assigned to the Dominant motion vector

DMW Height Assignment • Uses GOES-R ABI Cloud Height Algorithm (ACHA) products: Cloud Mask, Cloud Type, Cloud Top Pressure, Cloud Top Temperature

DMW Verification statistics: Himawari-8/AHI vs Aircraft Compares favorably with GOES-R DMW specification: Mean Vector Difference (DMW vs RAOB/Aircraft/Model) Standard Deviation about the mean vector difference

INTRODUCTION AND SATELLITE METEOROLOGY BACKGROUND Himawari-8/AHI Visible and Infrared winds Operational Himawari-8 AMV Using 10 min. and 2 km resolution Himawari-8 Rapid Scan AMV Using 2. 5 min. and 0. 5 km (2 km for IR) ü Increase of data quality and quantity -> Improvement to DMW temporal and spatial resolution

INTRODUCTION AND SATELLITE METEOROLOGY BACKGROUND Super Typhoon Soudelor (05 August 2015) Himawari-8/AHI Visible winds and Water Vapor winds Visible winds Hurricane force winds (> 75 mph) Water Vapor winds

INTRODUCTION AND SATELLITE METEOROLOGY BACKGROUND Several studies have shown that better methods of DMW assimilation improves NWP model performance

INTRODUCTION AND SATELLITE METEOROLOGY BACKGROUND Model Verification: Jet Streak Intensity (Underestimated By RUC)

INTRODUCTION AND SATELLITE METEOROLOGY BACKGROUND Model Verification: Cloud-Top (200 -400 MB) Water Vapor Winds (Large Differences) Himawari-8/AHI Winds GFS Winds

INTRODUCTION AND SATELLITE METEOROLOGY BACKGROUND Model Verification: Low-level (850 -950 MB) Shortwave and Longwave IR Winds Himawari-8/AHI Winds (850 -950 mb) GFS Forecast Winds (900 mb)

INTRODUCTION AND SATELLITE METEOROLOGY BACKGROUND Application: Identification of a favorable vertical wind shear profile in the pre-storm environment

INTRODUCTION AND SATELLITE METEOROLOGY BACKGROUND Application: Identification of a favorable vertical wind shear profile in the pre-storm environment

INTRODUCTION AND SATELLITE METEOROLOGY BACKGROUND Application: identification of a pre-frontal trough axis across Arkansas, Texas

INTRODUCTION AND SATELLITE METEOROLOGY BACKGROUND Himawari-8/AHI Winds Displayed in AWIPS Low Level (P > 700 mb) Winds derived using Shortwave IR - Band 7 (3. 9 µm) – used at night Visible - Band 2 (0. 64 µm) - used in daytime > 48 kts 34 – 48 kts < 34 kts

INTRODUCTION AND SATELLITE METEOROLOGY BACKGROUND Himawari-8/AHI Winds Displayed in AWIPS Upper Level (250 -350 mb) Winds derived using Longwave Infrared - Band 14 (11. 2 µm) - day/night > 48 kts 34 – 48 kts < 34 kts 17

Summary • Derived Motion Winds calculated using 6 ABI bands: – – – Band 2 Band 7 Band 9 Band 10 Band 11 Band 14 (Visible, 0. 64 µm) (Shortwave Infrared, 3. 9 µm) (Upper-level Water Vapor, 6. 2 µm) (Mid-level Water Vapor, 6. 9 µm) (Lower-level Water Vapor, 7. 3 µm) (Longwave Infrared, 11. 2 µm) • Coverage area/time: Full Disk (60 minutes), CONUS (15 minutes), Mesoscale (5 minutes) • Accuracy compares well with RAOB/Aircraft/Models • Proper assimilation improves NWP model performance • Applications: model verification, mesoscale feature identification/tracking

Internet Resources • ATBD on Derived Motion Wind Vectors • ATBD on Cloud Heights • HWT Blog Post on Pre-Frontal Trough in DMWs • HWT Blog Post on Vertical Wind Shear in DMWs – Case over Texas referred to in training – Case over Missouri • All HWT Blogs on Derived Motion Wind Vectors • GOES-R Website