Last Deglaciation—Holocene Australian-Indonesian Monsoon Rainfall Changes Off Southwest Sumba, Indonesia
Previous studies suggested the multi-millennial scale changes of Australian-Indonesian monsoon (AIM) rainfall, but little is known about their mechanism. Here, AIM rainfall changes since the Last Deglaciation (~18 ka BP) are inferred from geochemical elemental ratios (terrigenous input) and palynolo...
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MDPI AG
2020-08-01
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| Series: | Atmosphere |
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| Online Access: | https://www.mdpi.com/2073-4433/11/9/932 |
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| author | Ryan Dwi Wahyu Ardi Aswan Khoiril Anwar Maryunani Eko Yulianto Purna Sulastya Putra Septriono Hari Nugroho Istiana |
| author_facet | Ryan Dwi Wahyu Ardi Aswan Khoiril Anwar Maryunani Eko Yulianto Purna Sulastya Putra Septriono Hari Nugroho Istiana |
| author_sort | Ryan Dwi Wahyu Ardi |
| collection | DOAJ |
| description | Previous studies suggested the multi-millennial scale changes of Australian-Indonesian monsoon (AIM) rainfall, but little is known about their mechanism. Here, AIM rainfall changes since the Last Deglaciation (~18 ka BP) are inferred from geochemical elemental ratios (terrigenous input) and palynological proxies (pollen and spores). Pollen and spores indicate drier Last Deglaciation (before ~11 ka BP) and wetter Holocene climates (after ~11 ka BP). Terrigenous input proxies infer three drier periods (i.e., before ~17, ~15–13.5, and 7–3 ka BP) and three wetter periods (i.e., ~17–15, ~13.5–7, and after ~3 ka BP) which represent the Australian-Indonesian summer monsoon (AISM) rainfall changes. Pollen and spores were highly responsive to temperature changes and showed less sensitivity to rainfall changes due to their wider source area, indicating their incompatibility as rainfall proxy. During the Last Deglaciation, AISM rainfall responded to high latitude climatic events related to the latitudinal shifts of the austral summer ITCZ. Sea level rise, solar activity, and orbitally-induced insolation were most likely the primary driver of AISM rainfall changes during the Holocene, but the driving mechanisms behind the latitudinal shifts of the austral summer ITCZ during this period are not yet understood. |
| first_indexed | 2024-03-10T16:41:43Z |
| format | Article |
| id | doaj.art-3e06d594c83142e48704745127fcd65f |
| institution | Directory Open Access Journal |
| issn | 2073-4433 |
| language | English |
| last_indexed | 2024-03-10T16:41:43Z |
| publishDate | 2020-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Atmosphere |
| spelling | doaj.art-3e06d594c83142e48704745127fcd65f2023-11-20T11:56:05ZengMDPI AGAtmosphere2073-44332020-08-0111993210.3390/atmos11090932Last Deglaciation—Holocene Australian-Indonesian Monsoon Rainfall Changes Off Southwest Sumba, IndonesiaRyan Dwi Wahyu Ardi0Aswan1Khoiril Anwar Maryunani2Eko Yulianto3Purna Sulastya Putra4Septriono Hari Nugroho5Istiana6Geological Engineering Study Program, Faculty of Earth Sciences and Technology, Institut Teknologi Bandung, Bandung 40132, IndonesiaGeological Engineering Study Program, Faculty of Earth Sciences and Technology, Institut Teknologi Bandung, Bandung 40132, IndonesiaGeological Engineering Study Program, Faculty of Earth Sciences and Technology, Institut Teknologi Bandung, Bandung 40132, IndonesiaResearch Center for Geotechnology, Indonesian Institute of Sciences, Bandung 40135, IndonesiaGeological Engineering Study Program, Faculty of Earth Sciences and Technology, Institut Teknologi Bandung, Bandung 40132, IndonesiaGeological Engineering Study Program, Faculty of Earth Sciences and Technology, Institut Teknologi Bandung, Bandung 40132, IndonesiaMining Engineering Study Program, Faculty of Engineering, Universitas Muhammadiyah Tasikmalaya, Tasikmalaya 46196, IndonesiaPrevious studies suggested the multi-millennial scale changes of Australian-Indonesian monsoon (AIM) rainfall, but little is known about their mechanism. Here, AIM rainfall changes since the Last Deglaciation (~18 ka BP) are inferred from geochemical elemental ratios (terrigenous input) and palynological proxies (pollen and spores). Pollen and spores indicate drier Last Deglaciation (before ~11 ka BP) and wetter Holocene climates (after ~11 ka BP). Terrigenous input proxies infer three drier periods (i.e., before ~17, ~15–13.5, and 7–3 ka BP) and three wetter periods (i.e., ~17–15, ~13.5–7, and after ~3 ka BP) which represent the Australian-Indonesian summer monsoon (AISM) rainfall changes. Pollen and spores were highly responsive to temperature changes and showed less sensitivity to rainfall changes due to their wider source area, indicating their incompatibility as rainfall proxy. During the Last Deglaciation, AISM rainfall responded to high latitude climatic events related to the latitudinal shifts of the austral summer ITCZ. Sea level rise, solar activity, and orbitally-induced insolation were most likely the primary driver of AISM rainfall changes during the Holocene, but the driving mechanisms behind the latitudinal shifts of the austral summer ITCZ during this period are not yet understood.https://www.mdpi.com/2073-4433/11/9/932Australian-Indonesian monsoonelemental ratiomarine palynologypaleoclimateLesser Sunda Islands |
| spellingShingle | Ryan Dwi Wahyu Ardi Aswan Khoiril Anwar Maryunani Eko Yulianto Purna Sulastya Putra Septriono Hari Nugroho Istiana Last Deglaciation—Holocene Australian-Indonesian Monsoon Rainfall Changes Off Southwest Sumba, Indonesia Atmosphere Australian-Indonesian monsoon elemental ratio marine palynology paleoclimate Lesser Sunda Islands |
| title | Last Deglaciation—Holocene Australian-Indonesian Monsoon Rainfall Changes Off Southwest Sumba, Indonesia |
| title_full | Last Deglaciation—Holocene Australian-Indonesian Monsoon Rainfall Changes Off Southwest Sumba, Indonesia |
| title_fullStr | Last Deglaciation—Holocene Australian-Indonesian Monsoon Rainfall Changes Off Southwest Sumba, Indonesia |
| title_full_unstemmed | Last Deglaciation—Holocene Australian-Indonesian Monsoon Rainfall Changes Off Southwest Sumba, Indonesia |
| title_short | Last Deglaciation—Holocene Australian-Indonesian Monsoon Rainfall Changes Off Southwest Sumba, Indonesia |
| title_sort | last deglaciation holocene australian indonesian monsoon rainfall changes off southwest sumba indonesia |
| topic | Australian-Indonesian monsoon elemental ratio marine palynology paleoclimate Lesser Sunda Islands |
| url | https://www.mdpi.com/2073-4433/11/9/932 |
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