Fig. 6: Mid-latitude circulation changes during 1981–2022.
From: Recent two decades witness an uptick in monsoon depressions over the northern Arabian Sea
a JJAS mean 200 hPa meridional wind trends (shaded, m s−1/decade) and zonal wind trends (contours: negative denote westerlies in black dashed, positive denote easterlies in blue solid) are overlaid with green contours indicating climatological zonal wind (U200 > 20 m s−1) for 1981–2022. The magenta box marks the East Asian jet (EAJ). Black arrows show the meridional gradient of the westerly jet. b Year-to-year EAJ variation (bars) with a 17-year running standard deviation. c Similar to (b), but for the 200 hPa meridional wind (m s−1) over 0°–160°E and 20° 60°N, showing the leading mode of EOF PC1 (bars) with a 17-year running mean. d Epochal difference (2001–2022 vs 1981–2000) in the standard deviation of U200, with the same magenta box in (d) as in (a).
