15-20 Nov. 20107 th IWTC, La Reunion Island1. 15-20 Nov. 20107 th IWTC, La Reunion Island2 Ken Knapp David Levinson Michael Kruk Howard Diamond Ethan

15-20 Nov. 20107th IWTC, La Reunion Island 1

Special Focus Session 2b:IBTrACS Activities and Updates


International Best Track Archive for Climate Stewardship

Ken KnappDavid Levinson

Michael KrukHoward Diamond

Ethan GibneyPaula Hennon

Carl Schreck, IIINOAA/NCDC


1630 -1645 IBTrACS Introduction

Discussions: 1645 – 1705 Best track parameters &

data quality 1705 - 1725 Best track continuity 1725 - 1745 Global Reanalysis

Conclusions: 1745 - 1800 IBTrACS wrap up

Outline


Introduction


Reanalysis using:◦ current understanding ◦ new techniques

WMO◦ Incorporate BT datasets into unified database◦ Make more homogeneous◦ Include metadata◦ New working group

BT experts define standards Establish reanalysis procedures

Operational agencies◦ Continue revising historical BT data◦ Denote how BT data were derived (e.g., wind/pres.)◦ Uncertainties in BT record should be determined and recorded

IWTC-VI – Costa Rica, 2006: Recommendations

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International◦ Many nations and agencies working together

Best Track◦ Information on tropical cyclones◦ Enormous impact on life and property worldwide

Archive◦ One-stop-shop

Climate◦ Global distribution◦ Cyclone intensity◦ Temporal variability

Stewardship◦ Maintaining data for future generations

What is IBTrACS?


What IBTrACS is not …◦ A reanalysis◦ Absolutely, every storm, that ever occurred

What IBTrACS is…◦ Collection◦ Combination◦ Collaboration◦ Centralization◦ Scalable◦ WMO-recognized


Data providers:◦ RSMCs: CPHC, IMD, JMA, La Reunion, Nadi, NHC◦ TCWCs: BoM, Wellington◦ Other: HKO, JTWC, CMA/STI

At WDC:◦ IBTrACS Team

Around the world:◦ Users providing feedback

IBTrACS: Who we are

915-20 Nov. 20107th IWTC, La Reunion Island

IBTrACS Data FormatsMultiple intensities possible 1 intensity per report

netCDF CSV

WMO HURDAT ATCF cXML GIS shapefile

Ver

. 1 Mean position

Mean intensityMean position JAOTMean intensity Kruk et al., 2010

Ver

. 2 Mean position BAMS

Mean intensity Knapp el al., 2010

Mean positionMean intensityOriginal positions & intensity

Ver

. 3 Original positions & intensityOther parameters as available

WMO position In prep.WMO intensity


IBTrACS: By the numbers 14 sources 31,002 total tracks 500,000+

observations

~11,774 storms 6757 TCs with MSW>30

1848-2009 1907-2009

1877-2009

1884-2009

1949-2009

1851-2009

1848 - 2009


5-7 May 2009 Participants worldwide Topics

◦ Operational Best tracking procedures◦ Wind-pressure relationships◦ Wind speed conversions◦ Global Reanalysis◦ IBTrACS improvements

Meeting summary in March 2010, BAMS

IBTrACS Workshop


The IBTrACS team should…◦ Document BT procedures,

Work with agencies Through a survey

◦ Provide all parameters as provided by original agency in IBTrACS

◦ Distribute official and unofficial datasets of other TC related data

◦ Archive all ancillary data◦ Get involved with the IWTC

IBTrACS Workshop recommendations


Best tracking agencies should …◦ Report more parameters and use WMO format

◦ Document current and historic BT practices

◦ Standardize definitions of winds and wind conversions

◦ Rescue and archive documents relevant to BT data

◦ “Best track” throughout life cycle (through ET)

◦ Encourage best track data discussions at IWTC

IBTrACS Workshop recommendations


Best Track Parameters and

Data Quality


A balancing act…

User needs

AvailableData

Forecaster/Analyst

Time


Storm name 11 ü ü ü ü ü ü ü ü ü ü üDate 15 ü ü ü ü ü ü ü ü ü ü ü ü ü ü üTime 15 ü ü ü ü ü ü ü ü ü ü ü ü ü ü ülatitude 15 ü ü ü ü ü ü ü ü ü ü ü ü ü ü ülongitude 15 ü ü ü ü ü ü ü ü ü ü ü ü ü ü ü

max avg wind speed 14 ü ü ü ü ü ü ü ü ü ü ü ü ü ücentral pressure 13 ü ü ü ü ü ü ü ü ü ü ü ü ücyclone type 13 ü ü ü ü ü ü ü ü ü ü ü ü üWind Radii by quadrant 5 ü ü ü ü üsource code 4 ü ü ü üRMW 4 ü ü ü üRMW quality 3 ü ü üpos_confidence 3 ü ü üwind units 3 ü ü üT-number 3 ü ü üCI-number 2 ü ütime interval for ws avg 2 ü ümax gust 2 ü üpressure quality 2 ü üunits of length 1 ügust period 1 üwind quality 1 ü ROCI 3 ü ü üEye diameter 3 ü ü üPressure _OCI 2 ü ü

# of Variables provided from WMO 17 10 7 3 3 3 3 3 4 4 2 3 9 5

Parameters in useW

MO

Par

amet

ers


From all agencies◦ Time, Latitude, longitude◦ Wind & Pressure◦ Cyclone type

From some agencies◦ Wind radii (5)◦ Radius of Maximum Winds (4)◦ Radius of outermost closed isobar (3)◦ Pressure of outermost closed isobar (2)◦ Dvorak Parameters: T-num and CI (2)

Parameter summary


IBTrACS requested users to identify their needs

Results…◦ Storm size information

RMW, Wind radii, ROCI◦ Higher temporal resolution

More the just 6 hourly Landfall, maximum intensity, etc.

User needs…


Based on the WMO best track format parameters, which parameter could be most easily added to the BT record from your agency?

What next parameter would be of the most use for users? (researchers, etc.)

What would it take to add:◦ Confidence flags?◦ Quality indicators?

Best Track Parameter Questions:


Best Track Continuity


An attempt to record historical operational “best tracking” practices

Questions include:◦ Are best track positions smoothed? If so, how?◦ Which year did your agency first begin acquiring

SSM/I (other microwave imagery)?◦ What other changes to in situ, radiosondes or

remote sensing data affected forecast and best tracking capability?

◦ How was the cyclone maximum sustained wind speed determined?

IBTrACS Community Survey


“There are limits to how precisely we can measure the locations and intensities even with in situ data, and the in situ sampling can be problematic. These problems get progressively worse the farther back in time one looks in the data. Satellite observations don’t exist before the 1960’s, and in situ data becomes far less systematic with time when looking back.”

Survey response:


Source of Best Tracks

Year Paper

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1959 (Chan and Shi, 1996) WP X

Var. (Henderson-Sellers et al., 1998) Global X X

1966 (Lander and Guard, 1998) Global X X

1958 (Emanuel, 2000) NA/WP X X

1945 (Emanuel, 2005) Global X X

1970 (Webster et al., 2005) Global X X X

1960 (Chan, 2006) WP X

1965 (Wu et al., 2006) WP X X X

1986 (Klotzbach, 2006) Global X X X

1970 (Hui et al., 2007) WP X X X

1989 (Knaff and Zehr, 2007) Global X X

1983 (Kossin et al., 2007) Global X X

1969 (Kuleshov et al., 2008) SH X X X

1979 (Lau et al., 2008) NA/WP X X

1945 (Lowry et al., 2008) WP X X X X

1965 (Wang et al., 2008) WP X X

IBTrACS Global X X X X X X X X X X X X

What areresearchersusing?

19441945195819601964196519651965197019701986


Regarding JTWC: Chu et al. 2002

◦ “The authors rate the 1985-2000 best-tracks to be of high quality and urge users to use older data with caution.”

Could a similar analysis be performed for other agencies/basins?

Data continuity and reliability


Assess dataset maturity based on the data◦ In use by the satellite data community

Assessment criteria include:◦ Algorithm stability◦ Metadata & Quality Assurance◦ Documentation◦ Validation◦ Scientific Applications

Could best track data be assessed with similar criteria?

Best Tracks as aClimate Data Record


IBTrACS 1st year Frequency Start◦ Global 1848 ?◦ NI 1877 ?◦ SI 1848 ?◦ WP 1945 ?◦ EP 1949 ?◦ SP 1907 ?◦ NA 1851 ?

What is a good starting year for analyzing TC frequency?


What criteria are used to decide an appropriate starting year?

What is a good starting year for analyzing TC frequency?◦ When do counts become reliable?

What is a good starting year for analyzing TC intensity?◦ When do intensities become reliable?

What’s the best road forward to analyze continuity in each basin?

Questions:


Global Reanalysis


Number of agencies “best tracking” each storm

Combining multiple sources


Increasing or decreasing?

Trends: Western Pacific

Emanuel, 2005

Wu et al., 2006


Application:Prioritize Reanalysis

Maximum intensity? Accumulated uncertainty!

Western North Pacific

Year Name

1951 Marge

1952 Bess

1954 June

1959 Tilda

1969 Ida

Max MSW ( kt)

175 - 88 = 87

146 - 88 = 58

165 - 114 = 51

165 - 110 = 55

156 - 100 = 56

ΔACE(104 kt2) ΔPDI (106kt3)

40 66

20 30

25 40

23 40

21 34

Annual PDI ~ 150

175 kt @ 10-min

88kt @ 10-min


Application: Prioritize Reanalysis

Year Name Max MSW (kt) ΔACE(104 kt2)

ΔPDI (106kt3)

1971 Sally 88 - 40 = 48 8 5

1971 Sheila/Sophia

110 - 62 = 48 8 8

1985 Isobel 84 - 44 = 40 10 8

1987 Elsie 97 - 53 = 44 8 6

1992 Irna/Jane 126 - 75 = 51 19 22

Southern Indian Ocean

Year Name Max MSW (kt) ΔACE(104 kt2)

ΔPDI (106kt3)

1972 Carlotta 97 - 57 = 40 28 23

1972 Gail 92 - 55 = 37 12 10

1972 Wendy 106 – 70 = 36 19 16

1972 Emily 92 - 57 = 35 8 7

2004 Fay 106 – 79 = 27 19 19

South Pacific

Annual PDI ~ 70

Annual PDI ~ 39


North Atlantic◦ HURDAT reanalysis effort◦ Currently ~1940s ◦ Moving forward

South Indian Ocean (MeteoFrance)◦ Dvorak Reanalysis of AVHRR data prior to 1998

Others??

Reanalysis underway


HURSAT-AVHRR 1978-present 4km resolution ~12 hourly netCDF

HURSAT: A tool for reanalysisHURSAT-MW 1987-present ~ 25 km resolution ~ 12 hourly (or better) netCDF & imagery

HURSAT-B1• 1978-present• 8km resolution• 3 hourly• netCDF &

MPG movies

GridSat – Globally Gridded Satellite

• 1978-present• 8km resolution• 3 hourly• netCDF

HR Mitch

HR WilmaHR IvanHR JeanneHR KarlHR Lisa

Typhoon Tip


What data could be prepared to aid a global reanalysis?

How could the TC community start the process of a global reanalysis?

Are there overlaps/synergies that can be exploited?

How would a reanalysis best be coordinated?

Global Reanalysis Questions


Conclusion


http://www.ncdc.noaa.gov/oa/ibtracs/ Google: IBTrACS

Finding IBTraCS

http://www.ncdc.noaa.gov/oa/ibtracs/


120+ registered users Kudos

◦ “Even though IBTrACS is still evolving, your efforts at homogenization on a global scale are very important.”

◦ “Congratulations for getting this complete and publicly available! Keep up the great work!”

Feedback◦ Error corrections◦ Parameter requests – radius maximum winds, etc.

Contact Us at [email protected]

User feedback


Take the survey online:www.surveymonkey.com/s/ibtracs

Or complete the survey via◦ Email◦ Word document◦ Phone◦ Talk with us at a conference◦ …

IBTrACS Community Survey


Include more variables◦ “If they provide it, so do we”◦ ROCI, RMW, Eye Diameter, T num, CI, …

Include non-developing storms◦ Forecast aid development

Document tropical cloud clusters Other agencies as available

Planned improvements


11-15 April 2011 Honolulu, Hawaii Discussions on:

◦ Operational best tracking procedures◦ Best track parameters◦ Best track data continuity◦ User needs ◦ Global reanalysis

IBTrACS 2nd Workshop


Backup slides


IBTrACS structure

IBTrACS Team

RSMCsTCWCsOthers

IBTrACSData

Users

Feedback

Create data

Data access

Data providers

Feedback

Publications

Peerreview

Workshop

Recommendations

Recommendations


Track of 1992 Typhoon Yvette

IBTrACS MergingPosition Pressure Wind Speed


Direct interactions BT Panel

New structure ideas

WMO-recognizedIBTrACS Team

RSMCsTCWCsOthers

IBTrACSData

Users

Feedback

Create data

Data access

Data providersRecommendations

Feedback

Pubs

Peerreview

Workshops:- IWTC- IBTrACS-

Conferences

Recommendations

Recommendations

WMO-recognizedIBTrACS Team

RSMCsTCWCsOthers

IBTrACSData

Users

Feedback

Create data

Data access

Data

Feedback

Pubs

Peerreview

ResultsRecommendations

WMO-BT Expert

PanelMembership

Workshops:- IWTC- IBTrACS-

Conferences

Requirements

Recommendatio

ns


Storms per decade

Storm frequency


Maximum intensity

Mean Intensity (kt)

StormIntensity


Range in wind speed (kt)

Relative range (%)

InteragencyDifferences


Changes in interagency differences


Interagency differences:North Indian Ocean


Interagency differences:South Indian Ocean


Interagency differences:South Indian Ocean through time


Interagency differences:Western Pacific Ocean


Interagency differences:Western Pacific Ocean through time


Interagency differences:South Pacific Ocean


Interagency differences:South Pacific Ocean through time


Global coverage Geostationary and polar orbiting 1979 to present

HURSAT Samples

Cyclone Daryl-Agnielle11/21/1995 03:00 UTC

Strongest TC in Indian Ocean

885 mb

Hurricane Wilma10/19/2005 09:00 UTCStrongest TC in North

Atlantic

882 mb

Cyclone Zoe12/28/2002 03:00 UTC

Strongest TC in Southern Pacific

879 mb

Typhoon Gay (Western Pacific)11/20/1992 20:15 UTC

Strongest TC on Earth since 1979

872 mb


More reanalysis needed… Landsea et al (2006)

hypothesize:“subjective measurements and variable procedures lead to biases in the tropical cyclone intensity record”

Support by showing 5 storms over Indian Ocean

Storms were stronger than analyzed


Reanalyzing AVHRR


Reanalyzing AVHRR


Documents

15-20 Nov. 20107 th IWTC, La Reunion Island1. 15-20 Nov. 20107 th IWTC, La Reunion Island2 Ken Knapp David Levinson Michael Kruk Howard Diamond Ethan