Figure 5
(a) The atmospheric blocking high system that formed over the Bering Sea in September 2018. The anomaly of the geopotential height at 500 hPa pressure level (z500) was calculated from the ERA5 dataset for September of 1979–2018. (b) The time series of September monthly z500 averaged over the study area enclosed by the red lines in (a) for the period of 1979–2018. The red circle indicates the year 2018. The blue solid line indicates the climatological mean from 1979–2018. The blue dashed line indicates one standard deviation above or below the long-term mean. The map is created by the MATLAB_R2020a with the mapping package M_MAP v1.4 h using the m_coast function (http://www.eoas.ubc.ca/~rich/map.html).
