On modeling the paleohydrologic response of closed‐basin lakes to fluctuations in climate: Methods, applications, and implications

Abstract

AbstractClimate reconstructions using tree rings and lake sediments have contributed significantly to the understanding of Holocene climates. Approaches focused specifically on reconstructing the temporal water‐level response of lakes, however, are much less developed. This paper describes a statistical correlation approach based on time series with Palmer Drought Severity Index (PDSI) values derived from instrumental records or tree rings as a basis for reconstructing stage hydrographs for closed‐basin lakes. We use a distributed lag correlation model to calculate a variable, ωt that represents the water level of a lake at any time t as a result of integrated climatic forcing from preceding years. The method was validated using both synthetic and measured lake‐stage data and the study found that a lake's “memory” of climate fades as time passes, following an exponential‐decay function at rates determined by the correlation time lag. Calculated trends in ωt for Moon Lake, Rice Lake, and Lake Mina from A.D. 1401 to 1860 compared well with the established chronologies (salinity, moisture, and Mg/Ca ratios) reconstructed from sediments. This method provides an independent approach for developing high‐resolution information on lake behaviors in preinstrumental times and has been able to identify problems of climate signal deterioration in sediment‐based climate reconstructions in lakes with a long time lag.