NOAA/WDS Paleoclimatology - Taiwan 748 Year March-August Precipitation Reconstruction

From the late 1920s to the early 21st century, meteorological observations indicate a decreasing trend of precipitation in Taiwan, an island in the low latitudes of East Asia, with global warming. However, it is still unclear whether the decreasing trend of Taiwan precipitation can be physically linked to an increase in temperature. Here, we present an annually resolved precipitation reconstruction for Taiwan for 1259-2006 AD based on tree-ring width and oxygen isotope indices, which both reflect a high sensitivity to climatic changes. Over the past 748 years both, extremely dry and wet years accounted for 2.8% of all years and Taiwan precipitation can reflect the large-scale precipitation in the low latitudes of East Asia. Before the onset of global warming, the precipitation reconstruction exhibited four other significant decreasing trends during the 1380s-1440s, 1640s-1700s, 1720s-1790s and 1790s-1860s, and each decreasing trend was accompanied by an increase in Northern Hemisphere temperature. This implies that the decreasing trends in precipitation were affected by increasing temperature. We also found that large volcanic eruptions in the low latitudes of the globe played an important role in precipitation changes by influencing the El Nino/Southern Oscillation and Asian summer monsoon. Precipitation usually decreased in the second year after large tropical volcanic eruptions. Our reconstruction is the longest annual-resolution precipitation reconstruction for the low latitudes of East Asia, and it is useful not only for understanding past hydroclimate changes but also for providing basic data to project future precipitation changes through climate modeling.