Meteorology and Boundary Layer Structure Associated with Coastal Low-Level Jets During WFIP3

Wind energy is a form of renewable energy that has been growing in implementation and use over the past years. The Department of Energy (DOE)’s 2015 wind vision study projected that wind energy will provide over a third of the United States’ electricity by 2050. Even with wind energy’s booming progress, focus in the U.S. has been mainly on onshore wind energy, with relatively little development of offshore wind energy. However, this situation is rapidly changing, with a number of new offshore leases being issued to advance offshore wind energy generation. The National Oceanic and Atmospheric Administration (NOAA) and other organizations, including the DOE, have sponsored the third Wind Forecast Improvement Project (WFIP3), a coordinated field campaign and analysis designed to improve offshore wind forecasting. The field observation portion of WFIP3 was officially launched in February 2024.

This work focuses on the characterization of low-level jets (LLJs), jet streams found in the lower troposphere, that take place over both Block Island, RI and Nantucket, MA (two of the WFIP3 sites) during the spring and early summer season. Individual LLJ cases were analyzed using observations from various WFIP3 instruments including radar wind profilers, infrared spectrometers, and microwave radiometers. Additionally, the meteorological patterns associated with the LLJs were investigated. Preliminary results suggest, through analysis of the thermodynamic structure of the marine atmospheric boundary layer, that LLJs with predominantly southerly flow seem to correlate with warm air advection and periods of strengthened near-surface stability. The mechanisms that drive LLJs in regions off the U.S. east coast are relatively unknown making it an important area of study, especially since LLJ events seem to have larger errors in the High-Resolution Rapid Refresh (HRRR) model’s wind forecasts. Since the presence of LLJs and their levels of shear can both affect overall wind power generation as well as cause unwanted damage to wind turbines, it is important to learn to better forecast them.