Daniel M. Cleary

Pusan National University | PNU · IBS Center for Climate Physics

Currently there is a scarcity of paleo-records related to the North Atlantic Oscillation (NAO), particularly in East-Central Europe (ECE). Here we report δ15N analysis of guano from a cave in NW Romania with the intent of reconstructing past variation in ECE hydroclimate and examine NAO impacts on winter precipitation. We argue that the δ15N values...

Fewstudies have attributed δ15N values of guano to a factor other than diet. A δ15N record obtained froma 1.5-m core of bat guano deposit from Zidită Cave (western Romania) provides a record of anthropogenic and climatic influence on the regional nitrogen pool. Nitrogen content is nearly constant (%N N 9) for over 1 m of the core, indicating limite...

Due to multiple factors influencing orbital-scale variability of the East Asian Summer monsoon (EASM), the interpretation of speleothem-based climate reconstructions from this region has remained challenging. Using a 130,000-year accelerated astronomically-forced simulation conducted with the isotope-enabled Community Earth System Model, we determi...

Cryogenic cave carbonates have been described from several formerly or presently glaciated karst caves. In most of these occurrences, they precipitated as loose grains or aggregates with various morphologies and sizes. Here, we report on a new speleothem type ( cryogenic ridges ) identified in Sohodoalele Mici Cave (SW Romania) within a large chamb...

The results of this study demonstrate the utility of guano-derived δ13C and δ15N records originating in environments experiencing droughts over prolonged periods of time. The shifts in δ15N values largely track the local aridity, indicating its control for the local N-cycle. Therefore, longer guano-derived δ15N records from such environments could...

The rhizosphere is a highly dynamic zone bridging plant roots with needed nutrient resources in soil. While the rhizosphere may be small, it has a disproportionally large impact on plant success and biomass production. A suite of rhizosphere-hosted microbial and geochemical interactions facilitate nutrient acquisition by plant roots, and, in turn,...

Capillary Absorption Spectroscopy (CAS) is a relatively new analytical technique for performing stable isotope analysis. Here, we demonstrate the utility of CAS by recording and quantifying variation in ¹³C in controlled and biologically relevant applications. We calibrated CAS system response to increased ¹³CO2, with an observed ∼4‰ increase in me...

Stable isotope ratios of cave bat guano reflect environmental influences at the soil and plant level within the foraging range of the bats. Carbon, nitrogen and hydrogen isotopes have utility in reconstructing precipitation, temperature as well as in tracing the influence of large-scale atmospheric circulation and climate variability. Guano-derived...

Two cores of bat guano were recovered from Topolnița and Gura Ponicovei Caves in the south-west region of Romania and analyzed for δ ¹⁵ N, δ ¹³ C and pollen. Deposition of guano began in CE 1537 at Gura Ponicovei and CE 1694 at Topolnița, allowing for the development and interpretation of climate and vegetation records since the Little Ice Age. δ ¹...

A 285‐cm core of bat guano was recovered from Măgurici Cave in north‐west Romania and analyzed for δ¹³C, δ¹⁵N and pollen. Guano deposition occurred from AD 881 until 1240 and from AD 1651 to 2013, allowing for the interpretation of summer variations in precipitation and temperature during the Medieval Warm Period (MWP) and the Little Ice Age (LIA)....

δ13C and δ15N analysis was completed on a 285 cm guano deposit found in Măgurici Cave (NW Romania). A hiatus was found in the ~1.2 ka core between AD 1240 to AD 1651 that appears to correspond with the beginning of the Little Ice Age. δ13C values indicate that vegetation was exclusively C3 plants in the region since AD 800, therefore δ13C values of...