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Microwave Imager TC Applications

Naval Research Laboratory, Monterey, CA2Jet Propulsion Laboratory, Pasadena, CA

3Science Applications Inc. International, Monterey, CA

Jeff Hawkins, Kim Richardson, Mindy Surratt, Tom Lee, Rich Bankert, Joe Turk2, Charles Sampson, Jeremy

Solbrig, Arunas Kuciauskas, John Kent3,

International Workshop on Satellite Analysis of Tropical Cyclones (IWSATC)

Honolulu, HIApril 15, 2010

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Exposed LLCC

Sheared Convection

Apparent LLCC

True LLCC

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Good central mass

Remove doubt

Large rain-free eye

Rainband structure

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Automated Tropical Cyclone Forecasting (ATCF) System warning graphic

Latest 1-km Visible/IR imagery

(GEO/LEO)

30 minute MTSAT refresh with

AVHRR/OLS as available

Vis/IR imagery

suite

Scatterometer & CloudSat

Storm Basins

& Names

Microwave imager/sounder product suite

http://www.nrlmry.navy.mil/TC.html

FNMOC: https://www.fnmoc.navy.mil/tcweb/cgi-bin/tc_home.cgi

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Microwave Imager Temporal Changes

512

km

Katrina

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14 d

eg

Tropical Cyclone Yasi

Microwave Imager Temporal Changes

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Concentric Mode 1: Evolve into one larger diameter eye

512

KM

Microwave Imager Temporal Changes

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Satellite – Aircraft Comparisons

North

NW

TMI 85H 9-22-05 1443Z

NOAA 43 1430-1520Z 10,000’

TMI Tb

Flt level wind

9Courtesy: Tom Lee

COMET Module – TC Microwave

http://meted.ucar.edu/npoess/ocean_winds/index.htm

TC specific focus with microwave sensors

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Microwave Imager Training

http://www.nrlmry.navy.mil/training-bin/training.cgi

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Automating TC Intensity???

Huge-Intense Shear - Weak Annular - Intense

Small-IntenseWrapping? Wrapping

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Microwave Imager TC Intensity Estimation

Machine LearningApplication

Leave-One(TC)-Out Cross Validation

Training and Testing

Atlantic Basin Data Set**319 samples from 60 TC’s**

RMSE: 13.1 kts

Segmented 85 GHz

Image feature extraction

Feature selection to reduce redundant and

irrelevant features

GOES Visible SSM/I 85 GHz

Microwave imager data provides structural characteristics not

always found in typical Vis/IR imagery.

Courtesy: Rich Bankert

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Microwave Imager Top Impact “Features”

6. Area coverage of pixels with less than 228 K Tb

7. Number of 1-km rings (within 1-deg radius) with at least 33% pixels with < 253 K Tb

8. Average % encirclement of the 1-km wide rings within 1-2-degree radius (pixels < 253 K)

9. Maximum summation of pixel Tb values along a 1-km ring for pixels with < 228K Tb

10. Number of 1-km rings (within 1-deg radius) with at least 50% pixels with Tb < 253 K

1. Symmetry measure – based on the 2-deg radius gradient vector angles relation to center

2. Average % encirclement of 1-km wide rings within 1-deg radius area (pixels < 253 K)

3. Difference in Tb of warmest center pixel and coldest surrounding pixel

4. Summation of pixel Tb in the SE quadrant of the “eye” region

5. Average of the maximum Tb on each ring in the 1-degree radius area

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IR Image GradientGradient DetailDetail

ArtificialArtificial Vortex Vortex GradientGradient DetailDetail

Ritchie: Gradient Vector Feature

15TIMELINE

RMSE (kts)

12.0

15.0

14.0

13.0

20.0

21.0

19.0

18.0

17.0

16.0

• Cubist (machine learning tool) Cross Validation (CCV) - all original features

• Manual estimation (Jeff)

• CCV - new feature set (modified original, new features added)

• CCV - feature selection (remove redundant and irrelevant features)

• CCV - new features added to total set, re-do feature selection

• CCV - 277 samples - high shear samples removed, re-do feature selection (Jeff RMSE – 16.7 kts)

• CCV - 319 samples – add gradient vector (Ritchie) feature

Automated Microwave Imager TC Intensity Estimates319 Atlantic basin samples [1995-2005]Features computed from SSM/I 85 GHz channel data

• Manual estimation (Jeff)

TC Intensity – Microwave Imager

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Problematic TC Structure Cases

High Shear Center Convection Dying Inner Eye

SSM/I 85 GHz images (BT)

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TC intensity – Microwave Imager (2006-2009 Data Sets)

Adding Near Real-Time Data Sets from NRL-TC Web Page Includes AMSR-E, TMI, SSMIS in addition to original SSM/I

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TC intensity – Microwave Imager (Adding 37 GHz Data)

85 GHz H-pol37 GHz H-pol

Tropical Cyclone Yasi (11P)

85 GHz H-pol37 GHz H-pol

Typhoon Sinlaku (15W)

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F-15 SSM/I 0723Z Aqua AMSR-E 0332Z

85 GHz H-pol 89 GHz H-pol

F-17 SSMIS 0750Z

91 GHz H-pol

Colder Tb at higher frequencies imply stronger storm: Incorrect

Microwave Channel Intercalibration

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Hurricane Bonnie TB Simulations

Passive Microwave Channel Intercalibration Process

TMI 85 GHz H

AMSR-E 89 GHz H

TMI 85 GHz H - AMSR-E 89 GHz H

8-10 K Differences In Deep Convection

Huge potential to create issues:

- Qualitative assessments

- Quantitative analyses (intensity alg)

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SSM/I

TRMM

TMI

AMSR-E

AMSR

WINDSAT

SSMIS

FY-3

MWRI

Russia MTVZA

YEAR 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20

Primary mission Extended mission March 2011

Hawkins

Passive Microwave Imager Missions

Launches Future

Megha

Tropiques MADRAS

GCOM AMSR

GPM

DWSS-1

Satellite sensors soon to cease functioning