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Ocean Response to 2018 Atlantic Hurricane Season

Date: 
Wednesday, June 12, 2019

The 2018 Atlantic hurricane season featured 15 named storms. The season officially began on 25 May 2018 with the formation of Tropical Storm Alberto and ended on 31 October 2018 with the dissipation of Hurricane Oscar.

The evolution of the ocean response to the 2018 Atlantic tropical cyclones is evaluated using data from the NASA Multi-Scale Ultra-High Resolution (MUR) sea surface temperature (SST) and NASA Soil Moisture Active Passive (SMAP) sea surface salinity (SSS). The ocean response is clearly observed along the tracks of the 2018 Atlantic tropical cyclones with waters approximately 2°C cooler from normal along the hurricane track that persisted for several days. It is common to observe trails of cooler water, or cold wakes, along hurricane tracks as a result of wind-induced mixing and turbulence that brings cold waters at depth to the surface. Salinity freshening due to precipitation can also be seen along the hurricane tracks, as well as increased salinity from wind stress-generated vertical mixing. The ocean salinity response to hurricanes is a combination of two competing effects: 1) salinity freshening due to enhanced precipitation and 2) salinity increase due to wind stress-generated vertical mixing, wherein increased salinity from a mid-level maximum is brought to the surface.