Factors controlling isotopic composition of precipitation on Okinawa Island, Japan: Implications for paleoclimate reconstruction in the East Asian Monsoon region

Kuroshio subsurface water feeds the wintertime Taiwan Warm Current on the inner East China Sea shelf

“…The obtained slope of δ 18 O—salinity relationship in this study is similar to those previous results [ Zhang et al ., ; Kim et al ., ; Ye et al ., ], but the mixing line has a slightly higher intercept, which is attributed to relatively enriched δ 18 O value of the freshwater end‐member. In addition, it is interesting to note that some surface seawater samples (at 2 and 5 m depths) from the region (122.5°E, 31.25°N) have the isotopic and salinity values off the mixing line and point to the δ 18 O values of precipitation collected in Shanghai (Figure a), which falls within the range of δ 18 O values previously observed (−3.78‰ to −1.88‰ [ Peng et al ., ]; −4.3‰ to −1.61‰ [ Uemura et al ., ]) for wintertime precipitation in western pacific monsoon region. Such trend probably indicates the precipitation influence on the coastal water during the cruise period, consistent with the trend of surface water in eastern equatorial pacific [ Benway and Mix , ].…”

Characteristics of hydrogen and oxygen stable isotope ratios in precipitation collected in a snowfall region, Aomori Prefecture, Japan

“…The dexcess value has been used as a tracer of conditions affecting evaporation in oceanic moisture source regions, such as sea surface temperature and the relative humidity of the overlying air mass (Merlivat and Jouzel, 1979). Several studies have reported that d-excess values in precipitation in Japan vary seasonally (e.g., Waseda and Nakai, 1983;Satake et al, 1984;Uemura et al, 2012), and Uemura et al (2008) have shown that d-excess values of water vapor above the ocean surface correlate negatively with the relative humidity above the ocean and positively with sea surface temperature. In general, higher dexcess values indicate lower relative humidity in the oceanic moisture source region.…”

Factors controlling stable isotope composition of precipitation in arid conditions: an observation network in the Tianshan Mountains, central Asia

“…Jasechko et al, 2013Jasechko et al, , 2014 and reconstructing paleoclimate (e.g. Uemura et al, 2012;Thompson et al, 2013;Mariani et al, 2014). To investigate the basic spatiotemporal patterns of water isotopes, an in-situ observation network is a valuable resource.…”