ESSIC/CISESS Scientist C. Max Stevens is co-author on a new paper in Nature that reveals summer and winter temperature changes through the last 11,000 years, a period known as the Holocene.
The researchers analyzed a continuous record of water-isotope ratios from the West Antarctic Ice Sheet Divide ice core. The recovery of long-term climate proxy records with seasonal resolution is rare because of natural smoothing processes, discontinuities and limitations in measurement resolution. Insolation forcing, or the amount of solar radiation received at the Earth’s surface, is a primary driver of climate change. Insolation forcing acts through seasonal variations with direct impacts on seasonal climate. Whether the sensitivity of seasonal climate to insolation matches theoretical predictions has not been assessed over long timescales.
Summer temperatures in West Antarctica increased through the early-to-mid-Holocene, reached a peak 4,100 years ago and then decreased to the present. Climate model simulations show that these variations primarily reflect changes in maximum summer insolation, confirming the general connection between seasonal insolation and warming and demonstrating the importance of insolation intensity rather than seasonally integrated insolation or season duration. Winter temperatures varied less overall, consistent with predictions from insolation forcing, but also fluctuated in the early Holocene, probably owing to changes in meridional heat transport.
The results demonstrate how seasonal climate factors can affect paleoclimate proxies, such as water isotopes from ice cores, and they help constrain the estimated thickness change of the West Antarctic Ice Sheet during the Holocene.
C. Max Stevens is an assistant research scientist with the Earth System Science Interdisciplinary Center (ESSIC) at the University of Maryland and is a member of the Cryospheric Sciences Laboratory at NASA Goddard. He received a B.A. in mathematics and physics from Colorado College in 2005 and a PhD in Earth and Space Sciences from the University of Washington in 2018. His research is focused on understanding firn densification and hydrology using models and observations. He is the lead developer of the Community Firn Model.
To access the article, click here: “Seasonal temperatures in West Antarctica during the Holocene”.