15-20 Nov th IWTC, La Reunion Island1

15-20 Nov th IWTC, La Reunion Island2 Ken Knapp David Levinson Michael Kruk Howard Diamond Ethan Gibney Paula Hennon Carl Schreck, III NOAA/NCDC

15-20 Nov th IWTC, La Reunion Island3  IBTrACS Introduction  Discussions:  1645 – 1705 Best track parameters & data quality  Best track continuity  Global Reanalysis  Conclusions:  IBTrACS wrap up

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15-20 Nov th IWTC, La Reunion Island5  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 }

15-20 Nov th IWTC, La Reunion Island6  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

15-20 Nov th IWTC, La Reunion Island7  What IBTrACS is not … ◦ A reanalysis ◦ Absolutely, every storm, that ever occurred  What IBTrACS is… ◦ Collection ◦ Combination ◦ Collaboration ◦ Centralization ◦ Scalable ◦ WMO-recognized

15-20 Nov th IWTC, La Reunion Island8  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

Nov th IWTC, La Reunion Island Multiple intensities possible1 intensity per report  netCDF  CSV  WMO  HURDAT  ATCF  cXML  GIS shapefile Ver. 1 Mean position Mean intensity Mean positionJAOT Mean intensity Kruk et al., 2010 Ver. 2 Mean positionBAMS Mean intensity Knapp el al., 2010 Mean position Mean intensity Original positions & intensity Ver. 3 Original positions & intensity Other parameters as available WMO positionIn prep. WMO intensity

Nov th IWTC, La Reunion Island  14 sources  31,002 total tracks  500,000+ observations ~11,774 storms 6757 TCs with MSW>

15-20 Nov th IWTC, La Reunion Island Oct Inception May 2009 – IBTrACS Workshop (Asheville) Aug – Asia Oceania Geosciences Society (Singapore) Nov – RSMC Meeting (Brisbane) July 2009 – version 2 release Jul – Beta release Autumn 2009 – Dataset update Apr – AMS Tropical Conf. (Orlando) Dec – version 1 release Dec – AGU Conf. (San Francisco) Jan – Annual AMS Meeting (Phoenix) Mar – Inter-departmental Hurricane Conf (FL) 1 st Indian Ocean Tropical Conf. (Oman) Jul – AGU Western Pacific Geo. (Cairns) Feb – Int. Conf. SH Meteorology (Melbourne) ESRI Users Conf. (Washington DC) Jun – Permission to distribute data received from providers Dec – Original request for data from RSMCs and other agencies Semiannual Updates International meetings, workshops & conferences Jan – Typhoon Committee Meeting (Singapore)

15-20 Nov th IWTC, La Reunion Island12  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

15-20 Nov th IWTC, La Reunion Island13  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

15-20 Nov th IWTC, La Reunion Island14  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

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15-20 Nov th IWTC, La Reunion Island16 User needs Available Data Forecaster/ Analyst Time

15-20 Nov th IWTC, La Reunion Island17 Storm name11 Date15 Time15 latitude15 longitude15 max avg wind speed14 central pressure13 cyclone type13 Wind Radii by quadrant5 source code4 RMW4 RMW quality3 pos_confidence3 wind units3 T-number3 CI-number2 time interval for ws avg2 max gust2 pressure quality2 units of length1 gust period1 wind quality1 ROCI3 Eye diameter3 Pressure _OCI2 # of Variables provided from WMO WMO Parameters

15-20 Nov th IWTC, La Reunion Island18 all  From all agencies ◦ Time, Latitude, longitude ◦ Wind & Pressure ◦ Cyclone type some  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)

15-20 Nov th IWTC, La Reunion Island19  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.

15-20 Nov th IWTC, La Reunion Island20  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?

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15-20 Nov th IWTC, La Reunion Island22  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?

15-20 Nov th IWTC, La Reunion Island23  “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.”

15-20 Nov th IWTC, La Reunion Island24 Source of Best Tracks Year Paper Target RSMC Miami RSMC Honolulu JTWC RSMC Tokyo CMA/STI HKO Neumann BoM RSMC La Reunion TCWC Wellington RSMC Nadi RSMC New Delhi 1959 (Chan and Shi, 1996)WPX Var. (Henderson-Sellers et al., 1998)GlobalXX 1966 (Lander and Guard, 1998)GlobalXX 1958 (Emanuel, 2000)NA/WPXX 1945 (Emanuel, 2005)GlobalXX 1970 (Webster et al., 2005)GlobalXXX 1960 (Chan, 2006)WPX 1965 (Wu et al., 2006)WPXXX 1986 (Klotzbach, 2006)GlobalXXX 1970 (Hui et al., 2007)WPXXX 1989 (Knaff and Zehr, 2007)GlobalXX 1983 (Kossin et al., 2007)GlobalXX 1969 (Kuleshov et al., 2008)SHXXX 1979 (Lau et al., 2008)NA/WPXX 1945 (Lowry et al., 2008)WPXXXX 1965 (Wang et al., 2008)WPXX IBTrACSGlobalXXXXXXXXXXXX

15-20 Nov th IWTC, La Reunion Island25  Regarding JTWC:  Chu et al ◦ “The authors rate the 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?

15-20 Nov th IWTC, La Reunion Island26  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?

15-20 Nov th IWTC, La Reunion Island27  IBTrACS 1 st yearFrequency Start ◦ Global1848? ◦ NI1877? ◦ SI1848? ◦ WP1945? ◦ EP1949? ◦ SP1907? ◦ NA1851?

15-20 Nov th IWTC, La Reunion Island28  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?

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15-20 Nov th IWTC, La Reunion Island30  Number of agencies “best tracking” each storm

15-20 Nov th IWTC, La Reunion Island31 Increasing or decreasing? Emanuel, 2005 Wu et al., 2006

15-20 Nov th IWTC, La Reunion Island Maximum intensity? Accumulated uncertainty! Western North Pacific YearName 1951Marge 1952Bess 1954June 1959Tilda 1969Ida Max MSW (kt) = = = = =56 ΔACE(10 4 kt 2 )ΔPDI (10 6 kt 3 ) Annual PDI ~ min 10-min

15-20 Nov th IWTC, La Reunion Island YearNameMax MSW (kt)ΔACE(10 4 kt 2 ) ΔPDI (10 6 kt 3 ) 1971Sally = Sheila/Sophia = Isobel = Elsie = Irna/Jane = Southern Indian Ocean YearNameMax MSW (kt)ΔACE(10 4 kt 2 ) ΔPDI (10 6 kt 3 ) 1972Carlotta = Gail = Wendy106 – 70 = Emily = Fay106 – 79 = 2719 South Pacific Annual PDI ~ 70 Annual PDI ~ 39

15-20 Nov th IWTC, La Reunion Island34  North Atlantic ◦ HURDAT reanalysis effort ◦ Currently ~1940s ◦ Moving forward  South Indian Ocean (MeteoFrance) ◦ Dvorak Reanalysis of AVHRR data prior to 1998  Others??

15-20 Nov th IWTC, La Reunion Island35 HURSAT-AVHRR  1978-present  4km resolution  ~12 hourly  netCDF HURSAT-MW  1987-present  ~ 25 km resolution  ~ 12 hourly (or better)  netCDF & imagery HURSAT-B present 8km resolution 3 hourly netCDF & MPG movies GridSat – Globally Gridded Satellite 1978-present 8km resolution 3 hourly netCDF HR Mitch HR Wilma HR Ivan HR Jeanne HR Karl HR Lisa Typhoon Tip

15-20 Nov th IWTC, La Reunion Island36  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?

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15-20 Nov th IWTC, La Reunion Island38   Google: IBTrACS

15-20 Nov th IWTC, La Reunion Island39  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

15-20 Nov th IWTC, La Reunion Island40  Take the survey online:  Or complete the survey via ◦ ◦ Word document ◦ Phone ◦ Talk with us at a conference ◦ …

15-20 Nov th IWTC, La Reunion Island41  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

15-20 Nov th IWTC, La Reunion Island42  April 2011  Honolulu, Hawaii  Discussions on: ◦ Operational best tracking procedures ◦ Best track parameters ◦ Best track data continuity ◦ User needs ◦ Global reanalysis

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15-20 Nov th IWTC, La Reunion Island44 IBTrACS Team RSMCs TCWCs Others IBTrACS Data Users Feedback Create data Data access Data providers Feedback Publications Peer review Workshop Recommendations

15-20 Nov th IWTC, La Reunion Island45  Track of 1992 Typhoon Yvette Position PressureWind Speed

15-20 Nov th IWTC, La Reunion Island46 Direct interactions BT Panel WMO-recognized IBTrACS Team RSMCs TCWCs Others IBTrACS Data Users Feedback Create data Data access Data providers Recommendations Feedback Pubs Peer review Workshops: - IWTC - IBTrACS - Conferences Recommendations WMO-recognized IBTrACS Team RSMCs TCWCs Others IBTrACS Data Users Feedback Create data Data access Data Feedback Pubs Peer review Results Recommendations WMO- BT Expert Panel Membership Workshops: - IWTC - IBTrACS - Conferences Requirements Recommendations

15-20 Nov th IWTC, La Reunion Island47  Storms per decade

15-20 Nov th IWTC, La Reunion Island48 Maximum intensity Mean Intensity (kt)

15-20 Nov th IWTC, La Reunion Island49  Range in wind speed (kt)  Relative range (%)

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15-20 Nov th IWTC, La Reunion Island58  Global coverage  Geostationary and polar orbiting  1979 to present Cyclone Daryl-Agnielle 11/21/ :00 UTC Strongest TC in Indian Ocean 885 mb Hurricane Wilma 10/19/ :00 UTC Strongest TC in North Atlantic 882 mb Cyclone Zoe 12/28/ :00 UTC Strongest TC in Southern Pacific 879 mb Typhoon Gay (Western Pacific) 11/20/ :15 UTC Strongest TC on Earth since mb

15-20 Nov th IWTC, La Reunion Island59  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

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