FIGURE LEGENDS
Fig. 1 Typhoon migration route and the location of sampling station. The arrows roughly indicate the directions for the moisture transport. The purple arrow represents the continental moisture. The blue arrows represent the ocean-originated moisture including Pacific Ocean, Indian Ocean, and South China Sea.
Fig. 2 The variation of meteorological parameters, precipitation isotopes (δD and δ18O), and D-excess during the study period from June 2018 to August 2019. The data of meteorological parameters were obtained from China Meteorological Data Service Centre (http://data.cma.cn). The red box indicates the impact of typhoon processes on the study area, and the typhoon name is labeled in the figure. The dashed line of δD, δ18O, and D-excess represent monthly average value, which was calculated by a weighted average of precipitation amount, using the equation\(\delta=\sum_{i=1}^{n}{P_{i}\delta_{i}/\sum_{i=1}^{n}P_{i}}\), where \(P_{i}\) and \(\delta_{i}\) denote daily precipitation amount and its δ value.
Fig. 3 Typical time-series of different isotopic composition of precipitation with temperature and relative humidity in the normal condition.
Fig. 4 Time-series of isotopic composition of precipitation with temperature and relative humidity under the impact of (a) TD, (b) Typhoon Yutu, and (c) Typhoon Bailu.
Fig. 5 Local meteoric water line (MWLs) for the Xiamen, based on the data of (a) all individual samples, (b) typhoon-related precipitation samples, (c) summer monsoon samples from May to September, (d) winter monsoon samples from October to February, (e) seasonal shift period samples from March to April. The filled circles present typhoon precipitation samples, and the hollow circles present precipitation samples collected in normal condition. The red full line indicates global meteoric water line (GMWL, δD = 8δ18O + 10), and the black full line indicates China meteoric water line (CMWL, δD = 7.9δ18O + 8.2).
Fig. 6 The correlation (a) between δ18O and temperature, and (b) between δ18O and precipitation amount.
Fig. 7 Back trajectories (72 hours) of moisture sources calculated by HYSPLIT at 500 (red lines), 1000 (blue lines) and 2000 m (green lines) over Xiamen before the different typical precipitation.
Fig. 8 The correlation between δD and δ18O for different stages of typhoon-related precipitation.
Fig. 9 Back trajectories (72 hours) of moisture sources calculated by HYSPLIT at 500 (red lines), 1000 (blue lines) and 2000 m (green lines) over Xiamen before the precipitation during (a) Typhoon Maria, (b) TD, (c) Typhoon Yutu, and (d) Typhoon Bailu. The black dotted lines represent the migrate route of the typhoons.