Data rescue of historical typhoon tracks over the western north Pacific back to late 19th century

Hisayuki KubotaResearch Institute for Global Change,

Japan Agency for Marine-Earth Science and Technology (JAMSTEC)

Background・ Typhoon activity appears to be affected by global warming(Oouchi et al. 2006).・ On the other hand, typhoon activity hasnatural interdecadal variability(Yumoto and Matsuura 2001) .・ Typhoon database is created over theAtlantic basin from 1851(Landsea et al. 2004).・ However, over the WNP, typhoon databaseis available from 1945 by JTWC (Joint Typhoon Warning Center) best track data.

1877-

1877-

1945-

1949-1851-

by NCAR

Available global typhoon database

Seasonality of typhoon track1893-1918

Visher 1922 MWR

Major four typhoon track datasetwere used(Philippines, Japan, Hong Kong,and Zi-ka-Wei)

“For understanding the typhoon activity through the 20th century over the western north Pacific“ funded by the Grant-in-Aid for Scientific Research for Young Scientists (A) of the Ministry of Education, Culture, Sports, Science and Technology (MEXT) in Japan period : 2009-2011 budget: US$ 125,000 leader: Hisayuki Kubota (JAMSTEC) collaborators: Prof. Bin Wang (Univ. of Hawaii) Prof. Johnny Chan (City Univ. of Hong Kong) Dr. Mong-Ming Lu (Central Weather Bureau, Taiwan) Dr. Kumi Kataoka (Shumei Univ., Japan) Mr. Edwin W. L. Ginn (Hong Kong Observatory) Dr. Zhao Bingke (Shanghai Typhoon Institute)

Monthly Bulletins of Philippines Weather Bureau(1901-1940)stored in Hamilton Library　 at University of Hawaii(1891-1900 stored in JMA library)

300 stations observation dataTyphoon tracks over the WNP

Udias (1996) BAMS Introducing 19th-20th century meteorological observation over the world

Philippine weather observationSpanish (from 1865)American (20th century)meteorologists

Typhoon track and surface isobar map on May 1913

Typhoon tracks were detected by using station observations, ship obs. reports,reports of typhoon eyes and damages.

Historical typhoon track data collected and digitized over the western north Pacific　　　　

digitizedcollected

available

Philippines(Univ. Hawaii)

Japan(JMA library)

Hong Kong(Hong Kong Observatory)（ 1958 reedited）

Shanghai(Zi-Ka-Wei)(Shanghai observatory)（ 1957 reedited）

　 Philippine Weather Bureau

Central Meteorological Observatory Tokyo Japan and Taiwan

Hong Kong Observatory

Zi-Ka-Wei (Shanghai) Observatory

period 1902-1940 Aug. 1892-1977 1884-1953 1884-1957 coverage WNP WNP WNP up to 30N WNP

typhoon definitionless than 750mmHg (1000hPa)

N/A more than 64kt and others N/A

dataTyphoon locations and date

Typhoon locations and date, (some) center pressure

Typhoon locations and date

Typhoon locations and date

interval daily (some 6 hourly)

daily (some 6 hourly)

6 hourly interpolated daily

reference

Monthly Bulletins of Philippine Weather Bureau 1902-1940

Geophysical Review 1900-1950, Wadachi 1952: Typhoon tracks 1940-1950, Xu, H. et al. 1973: 80 years typhoon track 1892-1977

. Chin, P. C., 1958: Tropical cyclones in the Western Pacific and China Sea area from 1884 to 1953

Gao 1957: Typhoon tracks and statistical analysis

Historical typhoon track data over western north Pacific

Digital Tropical Cyclone tracks over the Western North Pacific from 1902 to 1940

Data source Monthly Bulletins of the Philippine Weather Bureau 1901-1940Datasets TC (tropical cyclone) track locationsData files TYByyyymmdd.a.dat (for example: TYB19020706.a.dat) yyyymmdd: It is the first date of each TC track.

Data formatYYYYMMDDHH lat lon type flag1902 7 6 12 12.19 128.34 2 11902 7 7 12 12.25 125.63 2 11902 7 8 12 12.57 123.54 2 11902 7 9 12 13.36 121.16 2 11902 7 10 12 14.70 118.30 2 11903 7 11 12 17.09 114.66 2 1HH: Philippine local time (+8 hours GMT)

This data is available at http://www.jamstec.go.jp/drc/maps/e/kadai/mon/mon_tt.html

flag1: types of TC 2: Tropical Storm or Typhoon (center pressure less than 750mmHg (about 1000 hPa)) 4: its intensity is unknown (Typhoon or Tropical Depression or Extra Tropical Cyclone) 8: Tropical Depression 1: report the TC heading direction

flag2: Quality Check is performed 1: satisfied (compared to other best track data) 4: failed (high possibility of extra tropical cyclone) 6: questionable (possibility of tropical depression or extra tropical cyclone) 9: not checked (for flag1: 4, 8, and 1)

I recommend of using only satisfied typhoon data with 2 in flag1 and 1 in flag2.

• 1945-2005 when TS passed over Philippines Max wind speed >35kt (JTWC TS best track data) (JMA best track data used for comparison)• 1902-1939 when TS passed over Philippines ps <1000hPa observed at station using Monthly Bulletins of Philippines Weather Bureau

Comparison between two definitions Typhoon landfall from 1951-1978 by “Tropical Cyclones Summaries from 1948 to 1978” by Bonjoc (1978)Max wind speed >35kt TS 124(JTWC), 124(JMA) Ps<1000 hPa 107 105 (difference 13.7%, 15.3%)

To check the reliability of the historical datasets

Typhoon definition compared by landfall numbers in the Philippines

Kubota and Chan 2009

Satisfied tracksFailed tracks

JTWC

Remove extra tropical cyclones

Ensembles of multi typhoon track datasets

Hong Kong

Philippines

Japan

Shanghai

• Restrict the target area, within 600km radius of each weather station•Check typhoon passage through the perturbation of the station pressure data

80% of typhoons passed target area (JTWC, JMA)

▼ : typhoon by Philippines dataset▼: typhoon by Hong Kong dataset▼: typhoon by Japan dataset

▲ :typhoon landed Philippines

Count enough numbers of typhoons throughout the yearnear Philippines from 1908

Quality check of the density of typhoon numbers over the WNP

Density of historical typhoon numbers over the target area

Until 1909 not satisfied1910 Combination of 3 typhoon track dataset1911-1939 Philippine Weather Bureau1940 Central Meteorological Observatory Tokyo Japan After 1941 not satisfied

Daily pressure data are available over the whole target area from 1907 to 1941

Historical daily rainfall dataset created from early 20th century

Japan 1901-2009

Taiwan 1901-2009Philippines 1901-2009

South Seas Bureau & WNP islands1923-2009Hong Kong 1884-2010

Typhoon numbers of the target area over the Western North Pacific

MBP+combinationJTWCJMA

:10 years running mean

10-20N>20N

<10NMBP, JTWC

JMA

Summary

• Historical typhoon tracks over the WNP were collected from Philippine Weather Bureau, Central Meteorological Observatory of Japan, Hong Kong Observatory, and Shanghai Observatory from late 19th century.

• Digital dataset of typhoon track locations are created.• Quality check of the typhoon definition and typhoon density were

performed. • Counting typhoon numbers over the target area is possible from 1910.• Typhoon numbers have interdecadal variability over the target area of

WNP. However, low latitude typhoons have decreasing trend during the past 100 years.