Tracing Past to Predict Future: Hydroclimatological Changes in Southeastern Iran

Introduction: The Earth's climate has historically experienced natural variations driven by factors such as solar insolation, orbital motion, orogeny, and ocean circulation patterns (Bytnerowicz et al., ۲۰۰۷; Nakicenovic et al., ۲۰۰۰). However, the industrial revolution has triggered significant human-induced climate change, characterized by a sharp increase in greenhouse gas emissions and resulting in global warming and notable alterations in climatic conditions (Le Treut et al., ۲۰۱۰; IPCC ۲۰۱۹). This is evident in the substantial rise in atmospheric carbon dioxide levels, primarily due to activities like fossil fuel combustion (IPCC ۲۰۱۹, ۲۰۲۱). While global average surface temperatures have shown a discernible warming trend, precipitation records demonstrate a variable response in both frequency and intensity (Archer and Rahmstorf, ۲۰۱۱; Konapala et al., ۲۰۲۰), sparking ongoing debate about the potential impact of global warming on future precipitation and its implications for agriculture and food supply (Donat et al., ۲۰۱۶). With the livelihoods of over two billion people in South and West Asia intricately linked to summer monsoon precipitation (Clift and Plumb, ۲۰۰۸; Cullen et al., ۲۰۰۰), understanding the potential evolution of monsoons amidst increasing greenhouse gas emissions and rising temperatures is essential (Turner and Annamalai, ۲۰۱۲). However, General Circulation Models (GCMs) encounter challenges in accurately simulating the regional distribution and intensity of monsoons due to complex physical processes and interactions influencing precipitation (Sperber et al., ۲۰۱۳). The concentration of greenhouse gases is expected to intensify monsoonal activity, primarily due to amplified land-sea temperature differences and a northward shift of the Inter-Tropical Convergence Zone (ITCZ) (Cao and Zhao, ۲۰۲۰; Li and Ting, ۲۰۱۷; Sachs et al., ۲۰۰۹). Southeastern Iran, influenced by the Indian Ocean Summer Monsoon (IOSM) and the Mid-Latitude Westerlies (MLW) precipitation zones, is highly susceptible to changes in climatic conditions (Hamzeh et al., ۲۰۱۶; Rashki et al., ۲۰۲۱; Vaezi et al., ۲۰۱۹). Paleoclimate evidence demonstrates significant changes in the intensity and variability of IOSM and MLW since the late Pleistocene, impacting regional hydrological conditions (Vaezi et al., ۲۰۱۹; Clift & Plumb, ۲۰۰۸; Stevens et al., ۲۰۰۱). Therefore, a comprehensive understanding of atmospheric circulation patterns and ancient precipitation patterns holds the potential to enhance assessments of future climate change scenarios and variations in regional precipitation patterns (Mehterian et al., ۲۰۱۷).

کلیدواژه ها:

Climate change ، temperature ، precipitation ، paleoclimate ، Southeastern Iran