ABSTRACT
Using the International Best Track Archive for Climate Stewardship (IBTrACS), the climatology of
tropical cyclones is compared between two global best track datasets: 1) the World Meteorological Organization
(WMO) subset of IBTrACS (IBTrACS-WMO) and 2) a combination of data from the National
Hurricane Center and the Joint Typhoon Warning Center (NHC1JTWC). Comparing the climatologies
between IBTrACS-WMO and NHC1JTWC highlights some of the heterogeneities inherent in these datasets
for the period of global satellite coverage 1981–2010. The results demonstrate the sensitivity of these climatologies
to the choice of best track dataset. Previous studies have examined best track heterogeneities in
individual regions, usually the North Atlantic and west Pacific. This study puts those regional issues into their
global context. The differences between NHC1JTWC and IBTrACS-WMO are greatest in the west Pacific,
where the strongest storms are substantially weaker in IBTrACS-WMO. These disparities strongly affect the
global measures of tropical cyclone activity because 30% of the world’s tropical cyclones form in the west
Pacific. Because JTWC employs similar procedures throughout most of the globe, the comparisons in this
study highlight differences between WMO agencies. For example, NHC1JTWC has more 96-kt (;49 m s21
)
storms than IBTrACS-WMO in the west Pacific but fewer in the Australian region. This discrepancy probably
points to differing operational procedures between the WMO agencies in the two regions. Without better
documentation of historical analysis procedures, the only way to remedy these heterogeneities will be through
systematic reanalysis.