Exploring the signatures and causes of climate change

North Pacific Climate Change over the Holocene

The main goal of these collaborative Dartmouth-UMaine-UNH-GSC projects is to reconstruct the history of atmospheric circulation, temperature and precipitation in Alaska and the North Pacific region during the Holocene, and evaluate their forcing mechanisms, using an array of ice core records. In May-June 2013, we collected two new ice cores to bedrock (208 m) from the Mt. Hunter Plateau in the Alaska Range of Denali National Park. These cores have been sampled with our continuous ice core melter, and analyzed for chemical concentrations and stable water isotopes to reconstruct past temperature, snow accumulation and storminess. These new records are being combined with an existing array of ice cores collected from the Wrangell, Saint Elias (Eclipse and Mt. Logan cores), and Brooks Range (McCall Glacier). Much of this research focuses on the changing strength of the Aleutian Low, which dominates wintertime climate in the North Pacific (see figure) and responds to tropical Pacific conditions (El Nino/La Nina). The project focuses on climate patterns during the Medieval Climate Anomaly (~800 to 1,200 years ago), the Little Ice Age (~200 to 600 years ago), and the modern industrial warming (last ~150 years). Check out the story and pictures of our 2013 drilling season on Mt. Hunter.

Publications: Polashenski et al., 2018; Winski et al., 2018; Osterberg et al., 2017; Osterberg et al., 2014; Zdanowicz et al., 2014; Campbell et al., 2013; Campbell et al., 2012a; Winski et al., 2012; Campbell et al., 2012b; Kelsey et al., 2010, Fisher et al., 2008; Fisher et al., 2004

Northeast USA Climate Change and Impacts

We are studying the record of temperature and precipitation change in the Northeastern USA since 1900 to evaluate the signature and pace of climate change, and assess its causes. Our current research is focused on the increase in extreme storms (determined by precipitation) in the Northeast over recent decades, and understanding its spatial variability (more along the coast or inland?), seasonality (more during winter or summer?), and underlying causes. We are also developing a next-generation model to study the effects of climate change, land-use patterns, and host dynamics on the spread of Lyme Disease. Our aim is to understand the relative importance of these factors in the rapid northward spread of the disease over recent years (see figure).

Publications: Huang et al., 2021; Winter et al., 2020; Wallace et al., 2019; Huang et al., 2019; Huang et al., 2018; Huang et al., 2017