Duckhole Lake, Tasmania 950 Year Sediment Reflectance and Temperature Reconstruction Saunders, K.M.; Grosjean, M.; Hodgson, D.A. Saunders, K.M. Grosjean, M. Hodgson, D.A. Air Temperature Reconstruction earth science/paleoclimate/climate reconstructions|paleolimnology (surface temperature,null,null,degree Celsius,annual,climate reconstructions|paleolimnology,filtered,null,N,based on sediment reflectance; 5 year filtered; calibrated model: R=-0.56 pauto<0.05 0.21C root mean squared error) earth science/paleoclimate/paleolimnology (depth,null,null,centimeter,null,paleolimnology,null,null,N,null) earth science/paleoclimate/climate reconstructions|paleolimnology (age,null,null,year Common Era,null,climate reconstructions|paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (age,null,null,year Common Era,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (age,null,null,calendar year before present,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (reflectance,sediment,null,dimensionless,null,paleolimnology,null,spectrophotometry,N,Trough area between 650 and 700 nm wavelength=Relative concentration of chlorins) earth science/paleoclimate/paleolimnology earth science/paleoclimate/paleolimnology (Duckhole Lake>LATITUDE -43.3647>LONGITUDE 146.875) A lack of quantitative high resolution paleoclimate data from the Southern Hemisphere limits the ability to examine current trends within the context of long-term natural climate variability. This study presents a temperature reconstruction for southern Tasmania based on analyses of a sediment core from Duckhole Lake (43.365S, 146.875E). The relationship between non-destructive whole core scanning reflectance spectroscopy measurements in the visible spectrum (380-730 nm) and the instrumental temperature record (ad 1911-2000) was used to develop a calibration-in-time reflectance spectroscopy-based temperature model. Results showed that a trough in reflectance from 650 to 700 nm, which represents chlorophyll and its derivatives, was significantly correlated to annual mean temperature. A calibration model was developed (R = -0.56, p auto < 0.05, root mean squared error of prediction (RMSEP) = 0.21C, five-year filtered data, calibration period 1911-2000) and applied down-core to reconstruct annual mean temperatures in southern Tasmania over the last c. 950 years. This indicated that temperatures were initially cool c. ad 1050, but steadily increased until the late ad 1100s. After a brief cool period in the ad 1200s, temperatures again increased. Temperatures steadily decreased during the ad 1600s and remained relatively stable until the start of the 20th century when they rapidly decreased, before increasing from ad 1960s onwards. Comparisons with high resolution temperature records from western Tasmania, New Zealand and South America revealed some similarities, but also highlighted differences in temperature variability across the mid-latitudes of the Southern Hemisphere. These are likely due to a combination of factors including the spatial variability in climate between and within regions, and differences between records that document seasonal (i.e. warm season/late summer) versus annual temperature variability. This highlights the need for further records from the mid-latitudes of the Southern Hemisphere in order to constrain past natural spatial and seasonal/annual temperature variability in the region, and to accurately identify and attribute changes to natural variability and/or anthropogenic activities. STUDY NOTES: Sediment reflectance data (650-700 nm trough, a proxy for Total chlorin) and temperature reconstruction for the past 950 years from Duckhole Lake, southern Tasmania, Australia. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Saunders, K.M. Investigator : Grosjean, M. Investigator : Hodgson, D.A. 2016-08-29 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/20452 https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/australia/duckhole2013refl.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/australia/duckhole2013temp.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/australia/duckhole2013refl.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/australia/duckhole2013temp.txt English https://www.ncdc.noaa.gov/paleo/study/20452 https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/australia/duckhole2013refl.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/australia/duckhole2013temp.txt KM Saunders, M Grosjean, DA Hodgson2013A 950 yr temperature reconstruction from Duckhole Lake, southern Tasmania, AustraliaThe Holocene236771-78310.1177/0959683612470176http://hol.sagepub.com/content/23/6/771.abstract START YEAR: 1067 AD * END YEAR: 2008 AD 146.875 -43.3647 146.875 -43.3647