How did permafrost thaw affect regional climate and environment in continental Siberia?

目前关于西伯利亚永久冻土的研究旨在重建过去气候中永久冻土生长的历史，调查与南极海冰相关的永久冻土下降，并检查永久冻土与碳循环动力学的关系（Vaks et al. 2013; Vaks et al 2020; Lechleitner et al. 2020）。之前的研究集中在生态位时间尺度上，通常是过去50万年，以评估全球温度和永久冻土范围之间的关系（Vaks等人，2013年; Pacton等人，2013年），尽管有些研究是在相对较近的时间尺度上（即Vaks等人，2020年）。本研究的研究目标主要是从Lechleitner等人（2020）承认的局限性中提取，这些局限性涉及洞穴沉积物记录识别永久冻土退化的化学特征的能力，这种情况发生的时间尺度，以及重建过去气候和识别控制这些过程的化学信号的能力（Leichleitner等人2018）。然而，这项研究基本上是在现有文献的基础上发展起来的，它明确地侧重于约42万年前的间冰期永久冻土融化古气候记录，以确定过去气候动力学相关的反馈和不同气候条件（即温度）下永久冻土的时空行为。因此，为了解决工作问题，本研究将试图回答以下研究问题（RQ）：1）在不同的变暖情景下，西伯利亚中部的冻土融化的位置和速度是否可以重建？2)对水分输送和西伯利亚生态系统有什么影响？3)博托夫斯卡娅洞穴的洞穴沉积物能准确地重建过去的温度变化吗？4)洞穴沉积物代用指标与当地和全球气候条件的关系是什么？

Current studies concerning Siberian permafrost have aimed to reconstruct the history of permafrost growth in past climates, investigate permafrost decline in association with Antarctic sea ice, and examine the relationship of permafrost to carbon cycle dynamics (Vaks et al. 2013; Vaks et al 2020; Lechleitner et al. 2020). Prior studies have concentrated on niche timescales, typically the past 500,000 years to assess the relationship between global temperature and permafrost extent (Vaks et al. 2013; Pacton et al. 2013), although some studies are on relatively recent timescales (i.e. Vaks et al. 2020). The research aims of this study would primarily pick up from the limitations acknowledged by Lechleitner et al (2020) concerning the capability of speleothem records to identify the chemical signatures of permafrost degradation, the timescale that this occurs on, as well as the capability to reconstruct past climate and the identification of chemical signals governing these processes (Leichleitner et al. 2018). However, this study would essentially develop on existing literature by distinctly focusing on interglacial permafrost thawing paleoclimatic records from ~420,000 years ago to identify past climate dynamics associated feedbacks and the spatio-temporal behaviour of permafrost under different climate conditions (i.e. temperature). Therefore, to address the working question, this study would attempt to answer the following research questions (RQ): 1) Can the location and speed of permafrost thaw in Central Siberia be reconstructed under different warming scenarios? 2) What are the repercussions for moisture transport and Siberian ecosystems? 3) Can speleothems from Botovskaya cave accurately reconstruct past temperature changes?4) What is the relationship of speleothem proxies to local and global climate conditions?