ORONO — Research led by University of Maine glaciologist Kristin Schild to quantify and predict iceberg melting rates has received NASA New (Early Career) Investigator Program (NIP) in Earth Science funding.
Schild received one of 38 NASA NIP awards and is the first Maine-based researcher to receive the triennial recognition since 2003.
The assistant research professor with the School of Earth and Climate Sciences and the Climate Change Institute will use her $378,446 award to develop universal measuring strategies and a model for predicting how fast any iceberg would melt and discharge freshwater into the ocean. These tools could support remote sensing and iceberg melt studies and enhance how global-scale models forecast sea level rise and climate change as a result of glacial ice activity.
“I’m incredibly honored to be selected as one of the NASA NIP recipients,” Schild says. “This is such an exciting project that tackles one of the fundamental questions concerning the changing cryosphere: where is this meltwater going and what is the impact? I’m beyond thrilled to start working on this research.”
Freshwater flux, or when freshwater enters the ocean, from tidewater glaciers accelerates sea level rise, and their contribution to it has more than doubled since the early 2000s. According to Schild, icebergs constitute about 50 percent of that contribution. They also have been connected with abrupt climate events across the globe.
Freshwater flux from melting icebergs also has increased in recent years, affecting local climates, ecosystems and local-scale fjord circulation, and posing challenges to shipping and offshore installations, Schild says.
Despite its various effects, iceberg freshwater flux is not considered in coupled atmosphere-ocean global climate models (GCMs), which are crucial for establishing climate thresholds, or points at which increasing temperatures would alter climate systems. Schild says GCMs forgo evaluating iceberg freshwater flux in part because no all-inclusive parameters for measuring iceberg geometry and quantifying melt rates have been established. By not accounting for it, however, Schild says GCMs neglect at least 50% of freshwater input into oceans from glaciers and other ice forms, which could skew forecasts.
Designing global metrics and a predictive model to anticipate the rate at which freshwater enters the ocean from any melting iceberg, which would give scientists a more comprehensive look at the effects of glacial ice and global warming by allowing GCMs to factor in the contributions of icebergs.
“This project expands the communities’ knowledge by taking the first step toward creating a series of iceberg geometries and a freshwater flux module for regular use in GCMs and global ocean circulation models,” Schild says. “Through these models, we will be able to promote better decisions about our environment and water.”
To establish universal parameters for obtaining iceberg geometry and melt rate figures, Schild plans to use Landsat satellite imagery, a 2D iceberg melt model and 46 years of onsite, full-iceberg geometric data collected on icebergs of varying shapes and sizes. Once she identifies the parameters, Schild can create her model.
Field data Schild obtained from her 2017–19 expeditions to Greenland will validate her parameters and predictive iceberg freshwater flux model.
In addition to identifying metrics for iceberg geometry for remote sensing and modeling studies, Schild also hopes to pinpoint the relation between the speed at which icebergs melt and their geometry, and the spatiotemporal distribution of iceberg freshwater flux.
“By understanding when, where and how much meltwater is injected, we will have a better handle on what type of environment we may see in the future,” Schild says.
Learn more about Schild and her research at https://umaine.edu/research/2021/04/05/schild-examines-impact-of-icebergs-on-ocean-circulation-climate-coastal-communities/.