Science Source

Trend Analysis with a New Global Record of Tropical Cyclone Intensity

States the historical global ‘‘best track’’ records of tropical cyclones extend back to the mid-nineteenth century in some regions, but formal analysis of these records is encumbered by temporal heterogeneities in the data
Holds this is particularly problematic when attempting to detect trends in tropical cyclone metrics that may be attributable to climate change
Applies a state-of-the-art automated algorithm to a globally homogenized satellite data record to create a more temporally consistent record of tropical cyclone intensity within the period 1982–2009
Utilizes this record to investigate the robustness of trends found in the best track data
Calculates the lifetime maximum intensity (LMI) achieved by each reported storm
Tests the frequency distribution of LMI for changes over this period
Applies a direct homogenization procedure in which post-1998 data are degraded to pre-1998 standards to address the unique issues in regions around the Indian Ocean, which result from a discontinuity introduced into the satellite data in 1998
Finds this additional homogenization step measurably reduces LMI trends, but the global trends in the LMI of the strongest storms remain positive, with amplitudes of around +1 m s-1 decade-1 and p value = 0.1
Finds regional trends, in m s-1 decade-1, vary from –2 (p = 0.03) in the western North Pacific, +1.7 (p = 0.06) in the south Indian Ocean, +2.5 (p = 0.09) in the South Pacific, to +8 (p < 0.001) in the North Atlantic