Typhoon tracks shift during the 20th century over the western north Pacific

Hisayuki KubotaResearch Institute for Global Change,

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

(Helen Reef in Palau)

Acknowledgements• Data Integration & Analysis System (DIAS)• Global Environment Research Fund B-061• Grant-in-Aid for Scientific Research 20240075 and 21684028

Cooperation with• Central Weather Bureau, Dr. Mong-Ming Lu• Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA), Dr. Susan R.

Espinueva• Hong Kong Observatory, Mr. Edwin W. L. Ginn• Shanghai Typhoon Institute, Dr. Zhao Bingke

Collaborators• Prof. Bin Wang (International Pacific Research Center, University of Hawaii)• Prof. Johnny C. L. Chan (Guy Carpenter Asia-Pacific Climate Impact Centre, City University of Hong Kong)• Dr. Mong-Ming Lu (Central Weather Bureau)• Prof. Jun Matsumoto (JAMSTEC/ Tokyo Metropolitan University)• Dr. Kooiti Masuda (JAMSTEC)

Sharing historical data with• Dr. Kumi Kataoka (Shumei University)• Prof. Chih-Wen Hung (National Taiwan Normal University)• Dr. Joo-Hong Kim (National Taiwan University)

Intensified TC increases associated with the increase of SST

Emanuel (2005)

PDI: Power Dissipation Index

However Chan (2006) insists TC trends is a part of inter-decadal variability.Longer dataset is needed to understandTC variability further.

Atlantic Ocean temperature and TCs trends

Knutson et al. (2010)

Available global tropical cyclone track datasets

1877-

1877-

1945-

1949-1851-

by NCAR

Purpose

•Historical typhoon track data are collected back to 19th century over the western North Pacific.

•Typhoon track dataset for 100 years is created over the western north Pacific.

• Typhoon variability is investigated during the past 100 years.

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

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

collected 2007-2008

First observation of TC passage by instruments at Manila in Sep 26-28 1865

Deppermann (1939)

barometer

temperature

humidity

wind direction

Typhoon track and surface isobar map on May 1913

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

Taiwan TC track data

Available data: TC location, central surface pressure, maximum wind speed

Shieh et al. (1998)

1897 and 1898

received from CWB on 2008

Seasonality of typhoon track1893-1918

Visher 1922 MWR

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

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, CMOJ 1951: 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 and Zeng 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

• 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”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)

• 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

Typhoon track dataset over the target area 1910-2009

1910 Combination of Philippine and Japan dataset1911-1939 Philippine Weather Bureau1940 Japan (Central Meteorological Observatory of Tokyo Japan)1941-1944 data missing1945-2009 Joint Typhoon Warning Center

Historical daily rainfall dataset created from early 20th century

Japan 1888-2009

Taiwan 1897-2009Philippines 1891-2009 South Seas Bureau & WNP islands

1923-2009Hong Kong 1884-2010

Korea 1904-2008

Manila Central Observatory + PAGASA

South Sea Bureau+PACRAIN

Typhoon numbers of the target area over the Western North Pacific

MBP+CMOJJTWC

JMA

:10 years running mean

10-20N>20N

<10NMBP, JTWC

JMA

Trends in typhoon numbers

5°×5°boxes

▲ ： 95% significant▲ ： 99% significant

Typhoon numbers differences (1910-39), (1980-2009)

1910-391980-2009

▲ ： 90% significant▲ ： 95% significant

Total annual20.2 (1910-39)20.5 (1980-2009)

Typhoon frequency difference (El Niño – La Niña)•: 95% significant

Discussions

Weakening of Walker circulation during 20th century

Vecchi (2006)

SLP Trends from 1861 from 1992

Eastward intensification of low-level westerly wind over tropical western Pacific

Trends from 1950 to 2008

Tokinaga et al. 2011 submitted

Summary• Historical typhoon track dataset during the 20th century is created. Collect historical typhoon track data during the early 20th century Digitize the data reported in books Perform the quality check compared to the present data Connect the data with the present available data

• Typhoon variability during the past 100 years is investigated. Typhoon numbers have inter-decadal variability but no trend over the target

area of WNP. Typhoon tracks have trends during the 20th century . Typhoon track tends to shift northward from low latitude to higher latitude, and

eastward from coastal region along Philippines Sea to the eastern region during the past 80 years.

To explain the typhoon track shift pattern, we need further discussions.

謝謝

Taiwan and Okinawa, HadSLP sea level pressure JJA

HadSLPTaiwan, Okinawa21years running mean correlation

+1000hPa

Stored in JMA library1899-1956By US Weather Bureau

Historical northern hemisphere Weather map