@article {thatcher_iberian_2022,
	title = {Iberian hydroclimate variability and the Azores High during the last 1200 years: evidence from proxy records and climate model simulations},
	journal = {Climate Dynamics},
	year = {2022},
	month = {08/2022},
	pages = {1{\textendash}23},
	abstract = {The state of the atmospheric circulation and the associated hydroclimate in the North Atlantic during the last millennium remain the subject of considerable debate in both proxy- and model-based studies. Of particular interest in the Iberian region is the Azores High (AH) system, the southern node of the North Atlantic Oscillation (NAO), an atmospheric dipole closely tied to regional hydroclimate. Hydroclimate-sensitive proxy reconstructions from this region offer some insights into atmospheric dynamics, but large spatiotemporal gaps in these data inhibit a robust evaluation of hydroclimate variability. In this study, we present a continuous, sub-decadally-resolved composite stalagmite carbon isotopic record from three partially overlapping stalagmites from Buraca Gloriosa (BG) cave, western Portugal, situated within the center of the AH, that preserves evidence of regional hydroclimate variability from approximately 800 CE to the present. Chronologies are derived from U/Th dating and annual laminae. Stalagmite carbon isotopic values primarily reflect the amount of effective moisture and reveal generally dry conditions during the Medieval Climate Anomaly (MCA; 850{\textendash}1250 CE) and Modern Climate/Industrial Era (1850 CE-present), and wetter conditions during the Little Ice Age (LIA; 1400{\textendash}1850 CE). Multidecadal to centennial variability in the BG record and state-of-the-art last millennium climate model simulations show considerable coherence with precipitation-sensitive records from Spain and Morocco that, like BG, are strongly influenced by the intensity, size, and location of the AH. Model-proxy synthesis suggests that western Portugal was persistently dry during much of the MCA consistent with other NAO reconstructions; however, even considering age uncertainties, the apparent timing in the transition from a relatively dry MCA to a wetter LIA is spatially variable and confirms the non-stationary behavior of the AH system indicated by model output.},
	keywords = {Azores High, Hydroclimate, last millennium, Last Millennium Ensemble, Paleoclimate, Stalagmite},
	doi = {10.1007/s00382-022-06427-6},
	url = {https://app.dimensions.ai/details/publication/pub.1150271437},
	author = {Thatcher, Diana L. and Wanamaker, A. D. and Denniston, R. F. and Ummenhofer, C. C. and Asmerom, Y. and Polyak, V. J. and Cresswell-Clay, N. and Hasiuk, F. and Haws, J. and Gillikin, D. P.}
}
@article {2827,
	title = {Equilibrium line altitudes along the Andes during the Last millennium: Paleoclimatic implications},
	journal = {The Holocene},
	volume = {27},
	year = {2017},
	month = {Feb-07-2018},
	pages = {1019 - 1033},
	abstract = {Deciphering the climate changes that influenced the glacial fluctuations of the last millennium requires documenting the spatial and temporal patterns of these glacial events. Here, we estimate the change in equilibrium line altitudes (ELAs) between the most prominent glacial advance of the last millennium and the present for four alpine glaciers located in different climatic regimes along the Andes. For each glacier, we reconstruct scenarios of climatic conditions (temperature and precipitation anomalies) that accommodate the observed ELA changes. We focus on the following glaciers: an alpine glacier in the Cordillera Vilcanota (13{\textdegree}S), Tapado glacier (30{\textdegree}S), Cipreses glacier (34{\textdegree}S), and Tranquilo glacier (47{\textdegree}S). Our results show that the range of possible temperature and precipitation anomalies that accommodate the observed ELA changes overlap significantly at three of the four sites (i.e. Vilcanota, Cipreses, and Tranquilo). Only Tapado glacier exhibits a set of climate anomalies that differs from the other three sites. Assuming no change in precipitation, the estimated ELA changes require a cooling of at least 0.7{\textdegree}C in the Cordillera Vilcanota, 1.0{\textdegree}C at Tapado glacier, 0.6{\textdegree}C at Cipreses glacier, and 0.7{\textdegree}C at Tranquilo glacier. Conversely, assuming no change in temperature, the estimated ELA changes are explained by increases in precipitation exceeding 0.52 m yr-1 (64\% of the annual precipitation) in the Cordillera Vilcanota, 0.31 m yr-1 (89\%) at Tapado glacier, 0.22 m yr-1 (27\%) at Cipreses glacier, and 0.3 m yr-1 (27\%) at Tranquilo glacier. By mapping the ELA changes and modeling the potential climate forcing across diverse climate settings, we aim to contribute toward documenting the spatial variability of climate conditions during the last millennium, a key step to decipher the mechanisms underlying the glacial fluctuation that occurred during this period.},
	keywords = {Andes, equilibrium line altitude, glacial fluctuations, glacial reconstruction, Holocene, last millennium},
	issn = {0959-6836},
	doi = {10.1177/0959683616678458},
	url = {http://journals.sagepub.com/doi/10.1177/0959683616678458},
	author = {Sagredo, Esteban A and Lowell, Thomas V and Kelly, Meredith A and Rupper, Summer and Aravena, Juan Carlos and Ward, Dylan J and Malone, Andrew GO}
}
