Intensification of southwestern Indonesian rainfall over the past millennium

Abstract

Modern precipitation in Indonesia is strongly correlated to variations in the Asian/Australasian monsoons, the Walker circulation, and migrations of the Intertropical Convergence Zone (ITCZ), but controls on multidecadal to millennial rainfall variations are less clear. We present a new, high‐resolution, precipitation proxy reconstruction from Lake Lading (8°S, 113°E), Java, from 850 Common Era (C.E.) to present, based on the δD of terrestrial plant waxes. We find that rainfall has steadily increased in Java over the past millennium. This increase persists into the twentieth century despite evidence from other tropical proxy records for a northward ITCZ migration during the last two centuries, which should introduce drier conditions to Java. Aspects of this long‐term increase in rainfall resemble records from the Northern Hemisphere, tropical Indo‐Pacific, suggesting that strengthening Walker circulation played an important role in this long‐term increase in rainfall and decrease in the δD of precipitation, while ITCZ variations may have been important to climate variations on multidecadal to centennial timescales.

ENSO and monsoon variability during the past 1.5 kyr as reflected in sediments from Lake Kalimpaa, Central Sulawesi (Indonesia)

“…Rodysill et al (2012) explain the trend as a consequence of migration of the Intertropical Convergence Zone (ITCZ) with increased precipitation during its southward displacement. In comparison, Konecky et al (2013) conclude that the migration of the ITCZ influences the climate variability on multidecadal to centennial time scales, while it is the strengthening of the Walker circulation and its associated changes in ENSO variability that produces the increasingly wetter climate during the last millennium. Yan et al (2011) arrive at similar conclusions, namely, precipitation changes in response to the combined influence of the migration of the ITCZ and the position and strength of the Pacific Walker circulation in the western tropical Pacific.…”

Intraseasonal Variability of δ¹⁸O of Precipitation over the Indonesian Maritime Continent Related to the Madden–Julian Oscillation

“…The isotopic content of precipitation or water vapor (δ 18 O and δD) has been used to reconstruct the atmospheric circulation (e.g., Burnett et al 2004), hydrological cycle, and paleoclimate (e.g., Konecky et al 2012). Dansgaard (1964) specifically mentioned an "amount effect" observed in tropical regions, which refers to the negative correlation between the precipitation amount and stable isotopes composition (Rozanski et al 1993;Araguás-Araguás and Froehlich 1998).…”

A Preliminary Study of Meteorological Drought Influences to Social Events over the Maritime Continent during The Last Millennium

“…Reinforced by the reconstruction of the 1,400-years-old lacustrine sediment proxy on the island of Java proves that Java is getting wetter. (Rodysill et al 2012;Konecky et al 2013). Yoden et al (2017) also state that the Last Millennium Intertropical Convergence Zone (ITCZ) migration moving over the Maritime Continent to the south causing intensification of rainfall in Java Island in the last two centuries.…”

“…2). This period is also noted as one of the most parched period in Java (1790( -1800( and 1840( -1900 based on the rainfall intensity reconstruction carried out by Konecky et al (2013). The The anomalies of the drought area are calculated using SPI-12 data in each category on each land grid.…”