Placing the 2012-2015 California-Nevada drought into a paleoclimatic context: Insights from Walker Lake, California-Nevada, USA

Abstract

Assessing regional hydrologic responses to past climate changes can offer a guide for how water resources might respond to ongoing and future climate change. Here we employed a coupled water balance and lake evaporation model to examine Walker Lake behaviors during the Medieval Climate Anomaly (MCA), a time of documented hydroclimatic extremes. Together, a 14C‐based shoreline elevation chronology, submerged subfossil tree stumps in the West Walker River, and regional paleoproxy evidence indicate a ~50 year pluvial episode that bridged two 140+ year droughts. We developed estimates of MCA climates to examine the transient lake behavior and evaluate watershed responses to climate change. Our findings suggest the importance of decadal climate persistence to elicit large lake‐level fluctuations. We also simulated the current 2012–2015 California‐Nevada drought and found that the current drought exceeds MCA droughts in mean severity but not duration.

Winter Snow Level Rise in the Northern Sierra Nevada from 2008 to 2017

“…Precipitation reductions during a multiyear drought from WY2012 to WY2015 were found to be consistent with average conditions that were estimated during the extreme and persistent Medieval droughts [13], with anomalous positive temperature anomalies enhancing drought severity [14]. Conversely, WY2017 was the wettest year in the past century and followed a near-average WY2016.…”

“…A severe drought during WY2012-2015 [12,13] was followed by subsequent average and record wet years during WY2016 and WY2017, respectively. The 67-year calculation of nine-station …”

“…A severe drought during WY2012-2015 [12,13] was followed by subsequent average and record wet years during WY2016 and WY2017, respectively. The 67-year calculation of nine-station median snow fractions indicated that high or low snow fractions ( Figure 5), and thus snow levels ( Figure 2) could occur during either wet or dry winters, as consistent with [42].…”

“…We have provided evidence that the snow-level radar and snow-fraction estimates appear to offer reasonable metrics to observe and evaluate precipitation phase change in snow-dominated watersheds [1,5,[28][29][30]. These changes will have marked effects on warm season streamflow [4], especially during drought years [13]-with negative implications for urban, ecological, and agricultural water demands [13][14][15]64]. If such a connection between SSTs, moisture plume strength, and snow fractions does exist, it suggests that snow accumulation may further decline with continued regional warming.…”

Five centuries of U.S. West Coast drought: Occurrence, spatial distribution, and associated atmospheric circulation patterns

“…Proxies such as lake sediment records that are able to extend the climate record of western North America further in time have also suggested a stable transition zone at approximately 40–42°N latitude [ Carter et al , ; Mensing et al , ]. These longer proxy records have identified centennial‐length droughts over the Holocene, including both sustained north‐dry/south‐wet and north‐wet/south‐dry conditions [ Barron and Anderson , ; Mensing et al , ; Dingemans et al , ; Hatchett et al , ], that may be linked to ENSO dynamics [ Shuman et al , ] or persistent high‐pressure ridging [ Stine , ]. Multiproxy research to extend paleoclimate records further in time at a greater spatial resolution would provide additional insight into the occurrence and climatic drivers of sustained drought events.…”