Fig. 3: Composite maps of the differences in environmental factors.
From: Recent increase in the potential threat of western North Pacific tropical cyclones
The environmental factors include a 600-hPa relative humidity (RH, %), b 200- and 850-hPa vertical wind shear (VWS, m/s), c 850-hPa relative vorticity (Vort, 10−5 s−1), d 200-hPa divergence (Div, 10−5 s−1), e sea surface temperature (SST, °C), and f tropical cyclone heat potential (TCHP, 107 J m−2) between Groups A and B. Data were obtained from the ERA5 and GLORYS reanalyses for atmospheric and oceanic variables, respectively. The atmospheric factors were averaged 1 day to 0 h prior to TC passage, while the oceanic factors were averaged 5 to 2 days before TC approaching. The unit for the x- and y-axes is degrees. Black dots indicate statistically significant differences at the 99% confidence level based on Student’s t-test. The three circles are placed at radii of 2°, 5°, and 10° from the TC center.
