High-resolution temperature and precipitation variability of southwest Anatolia since 1730 CE from Lake Gölcük sedimentary records

Abstract

We report high-resolution multi-proxy analyses (lithology, µXRF and magnetic susceptibility (MS)) of two short gravity sediment cores from the crater Lake Gölcük, southwest Turkey. Our results provide a detailed hydroclimatic record for the last ~290 years. Aided with factor analysis of µXRF data and 210 Pb and 137 Cs dating, our multi-proxy data show that the Lake Gölcük records documented a series of wet and dry periods between ~ 1730 (±71) and ~ 2018(±3) CE. Wet periods are evidenced by dark olive green mixed lithology (sandy, clay and silts) and high values in MS and log(Sr/Ca). On the other hand, dry periods are associated with light olive green clayey mud lithology and high values in log(Ca/K). We relate the wet periods to negative North Atlantic Oscillation (NAO-) and the dry periods to NAO+. Additionally, all wet periods are related with time of low solar activity and dry periods, except Dalton Minimum, are related with periods of high solar activity. Consequently, we suggest that hydroclimatic changes observed in the Lake Gölcük sedimentary records were caused by the influence of large scale atmospheric circulation and solar activity.

A Late Holocene climate reconstruction from the high-altitude Lake Gölcük sedimentary records, Isparta (SW Anatolia)

“…The justification is that warm summer temperatures lead to increase in precipitated calcium in water column. In fact, Danladi et al (2021) found the log(Ca/K) in Lake Gölcük to be a direct proxy for summer temperature. MS is a proxy for siliciclastic materials entering lacustrine environments and its high (low) values usually suggest high (low) input of siliciclastic materials in a lake (Thompson et al, 1976).…”

“…The relatively high δ 13 C and δ 18 O values between AD 450–730 imply dry climate conditions (Li and Ku, 1997; Roberts et al, 2008). The low log(Ca/K) values during this period indicate cold climate conditions (Danladi et al, 2021). Also supporting the multiproxy interpretation during this period, the dominance of Artemisia and Poaceae and low tree pollen ( Pinus , Juniperus type, Quercus [deciduous and evergreen]) suggest the prevalence of steppe vegetation under dry climate conditions.…”

“…The region is in a boundary close to the continental Anatolian and Mediterranean climate (Deniz et al, 2011). Instrumental records of the Isparta Province documented between 1929 and 2019 show an average annual temperature and precipitation of 12.2°C and 570.2 mm, respectively (Danladi et al, 2021). High pressure systems over Europe, North Africa, and monsoon regions combined with the Mediterranean SST influence the temperature and precipitation variations in the region (Bozkurt and Sen, 2011).…”

“…Because high (low) TSI in the Lake Gölcük record corresponds to wet (dry) periods, these climate changes may have been caused by solar activity, possibly through solar influence on mid-latitude westerlies. Danladi et al (2021) previously had demonstrated, through instrumental data and a 300-year paleoclimate reconstruction, that the Lake Gölcük climate changes are directly influenced by the TSI. Accordingly, the influence of solar activity on paleoclimate records has been observed in SW Anatolian Lake Salda (Akçer Ön, 2017; Danladi and Akçer-Ön, 2018), Lake Köyceğiz (Akçer Ön, 2017), and a tree-ring reconstruction in Antalya (Heinrich et al, 2013).…”