The impact of horizontal resolution on projected sea-level rise along US east continental shelf with the Community Earth System Model

Based on pre-industrial and historical-and-future climate simulations with the Community Earth System Model, we analyze the projected sea-level rise in the Northwest Atlantic Ocean with two sets of simulations at different horizontal resolutions. Compared with observations, the low resolution (LR) model simulated Gulf Stream does not separate from the shore but flows northward along the entire coast, causing large biases in regional dynamic sea level (DSL).

The high resolution (HR) model improves the Gulf Stream representation and reduces biases in regional DSL. Under the RCP8.5 future climate scenario, LR projects a DSL trend of 1.5-2 mm/yr along the northeast continental shelf (north of 40 degrees N), which is 2-3 times the trend projected by HR. Along the southeast shelf (south of 35 degrees N), HR projects a DSL trend of 0.5-1 mm/yr while the DSL trend in LR is statistically insignificant.