Fig. 2
From: Dust and sandstorm: ecosystem perspectives on dryland hazards in Northeast Asia: a review
Annual variations in the frequency of DSS occurrences in Seoul and other metropolitan cities in South Korea (Gwangju, Daegu, Daejeon, Busan, Ulsan, and Incheon) from 1960 to mid-May 2021. The charts show the average frequency of DSS occurrences by a month, b year, c for March and April, and d for March to May and October to December. The insert graph in b is power of the cycles (year) for the DSS timeseries. DSS data was obtained from the official website of the Korea Meteorological Administration (https://www.weather.go.kr/w/dust/dust-obs-days.do)