Fig. 6: Tropical cyclone genesis frequency (TCGF) in response to circulation anomalies forced by different oceanic modes.
From: Lapsed El Niño impact on Atlantic and Northwest Pacific tropical cyclone activity in 2023
a–c Scatter plots of North Atlantic (NA) TCGF and (a) westerly wind anomalies (unit: m s−1) averaged over 5°S-15°N; 10°-70°W, (b) 850 hPa relative vorticity anomalies (unit: 10−6 s−1) averaged over the 5°-30°N; 10°-70°W, and (c) vertical zonal wind shear (VZWS; unit: m s−1) between 200 hPa and 850 hPa averaged over 0°-15°N; 10°-70°W. d–f Scatter plots of TCGF over the east part of the western North Pacific (E_WNP) and (d) westerly wind anomalies (unit: m s−1) averaged over 5°S-15°N; 140°E-180°, (e) 850 hPa relative vorticity anomalies (unit: 10−6 s−1) averaged over the 5°-30°N; 140°E-180°, and (f) vertical zonal wind shear (VZWS; unit: m s−1) between 200 hPa and 850 hPa averaged over 0°-15°N; 140°E-180°. The JJASON-averaged anomalies of wind, vorticity and VZWS are derived from the different between Sensitive (PMM, TNA, PMM_TNA, No_ElNiño, No_GW and Reconstruction) Runs and Clim Run. The correlation coefficient between TCGF and circulation anomalies, and significance level are marked in each subplot. The green dots indicate results from the No_GW experiment, the purple dots from the Reconstruction Run, and the blue dots from the other 4 (PMM, TNA, PMM_TNA and No_ElNiño) Runs that do not contain the El Niño signal.
