Mainland Southeast Asia experiences complex and variable hydroclimatic conditions, mainly due to its location at the intersection of Asian monsoon subsystems. Predicting future changes requires an in-depth understanding of paleoclimatic conditions that is currently hindered by a paucity of records in some regions. In this paper, we present the first speleothem stable isotope records from western Thailand detailing the Bølling-Allerød interstadial, Younger Dryas termination, and early- to mid-Holocene period. We find evidence of higher precipitation during the Bølling-Allerød (14,321–12,824 years before present (1950: BP)) compared to a Younger Dryas termination that starts 11,702–11,674 BP, has a rapid shift centered on 11,660–11,641 BP, and ends 11,603–11,589 BP. In addition, our records show Holocene monsoon intensity peaking at 8250 BP or before, a multi-millennia delay from the Northern Hemisphere summer insolation peak, followed by a trend to drier conditions until at least 750 BP. Assessment of the timing of the Younger Dryas termination in paleoclimate records across Southeast Asia reveals an earlier shift of the Indian Summer Monsoon to global climate shifts when compared to East Asian Summer Monsoon records. The causes of this are currently unknown. Some potentially important aspects include: an Indian Summer Monsoon influence on East Asian Summer Monsoon strength via the Indian Ocean Dipole climate pattern, the role of the Tibetan Plateau in monsoon dynamics, and exposure of the Sundaland shoreline. More high-resolution paleoclimate records, especially on the pathway of Indian Summer Monsoon to East Asian Summer Monsoon, are required for further discussion on the mechanisms controlling the differences between climate regimes.

中文翻译：

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泰国西部的洞穴记录表明，在新仙女木期结束期间，印度夏季风发生了早期的快速转变

东南亚大陆地处亚洲季风子系统的交汇处，水文气候条件复杂多变。预测未来的变化需要深入了解古气候条件，而目前某些地区缺乏记录，这阻碍了这一点。在本文中，我们提出了来自泰国西部的第一个洞穴稳定同位素记录，详细介绍了 Bølling-Allerød 间质期、新仙女木终止期和全新世早期至中期。我们发现，与距今 11,702-11,674 年开始、以距今 11,660-11,641 年为中心并结束的新仙女木终止期相比，伯林-阿勒罗德期（距今 14,321-12,824 年（1950 年：BP））降水量更高的证据距今 11,603–11,589。此外，我们的记录显示，全新世季风强度在距今 8250 年或之前达到峰值，比北半球夏季日照峰值延迟了数千年，随后出现了干燥条件的趋势，直到至少距今 750 年。对东南亚古气候记录中新仙女木结束时间的评估表明，与东亚夏季风记录相比，印度夏季风向全球气候变化的转变更早。目前尚不清楚其原因。一些潜在的重要方面包括：印度夏季季风通过印度洋偶极子气候模式对东亚夏季季风强度的影响、青藏高原在季风动力学中的作用以及巽他海岸线的暴露。需要更多高分辨率的古气候记录，特别是关于印度夏季风到东亚夏季风路径的记录，以进一步讨论控制气候制度差异的机制。