A severe drought during the last millennium in East Java, Indonesia

The Little Ice Age (LIA) is characterized by widespread northern hemisphere cooling during a period of reduced radiative forcing. Sediment records from three crater lakes indicate that the most severe drought of the last 1200 years struck East Java at the end of the LIA. We use ¹⁴C and U-series dating applied to carbonate geochemical records from Lakes Lading, Logung, and Lamongan to demonstrate this drought occurred at 1790 Common Era (CE)±20 years. Drought occurred during a period of strong El Niño events and Asian monsoon failures in the late 1790s, yet our records indicate that drought conditions persisted well beyond this decade and reached peak intensity in East Java ca1810 CE±30 years. The continuation of severe drought into the 1800s may have resulted from the large volcanic eruptions that occurred in 1809, 1815 and 1835 CE, which likely caused brief, abrupt decreases in Indo-Pacific Warm Pool (IPWP) sea surface temperatures (SSTs), reducing local convection in East Java. Alternatively, broad changes in atmospheric circulation, such as a slowing of the Pacific Walker Circulation in response to decreased solar radiation during the LIA, could have produced several decades of drought in East Java. However, there is a lack of clear supporting evidence for such a change based upon paleohydrological records from the opposite ends of both the Indian and Pacific ocean zonal circulation systems. Based on the available evidence, we suggest severe multidecadal drought in East Java throughout the turn of the 19th century was driven by locally reduced convection resulting from a combination of heightened El Niño activity and volcanic eruptions.