One case study on how satellite and in situ ocean observations help to improve hurricane forecasts
Event: 2017 Ocean Surface Topography Science Team Meeting
Session: Application development for Operations
Presentation type: Type Poster
The tropical Atlantic basin is one of seven global regions where tropical cyclones (TCs) are commonly observed to originate and intensify. TCs translate through the region every year, frequently affecting coastal, highly populated areas. In an average year, 2 to 3 of them are categorized as intense hurricanes. Given the appropriate atmospheric conditions, TC intensification has been linked to the upper ocean heat conditions. While errors in hurricane track forecasts have been reduced during the last years, errors in intensity forecasts remain unchanged. Several studies have shown that upper ocean measurements, particularly of temperature and salinity, ahead of the passage of a TC, help identify areas where TCs may potentially intensify. More recently, studies have shown that the combined use of in situ and satellite observations has the potential to improve the representation of the ocean to correctly initialize hurricane intensity numerical forecast models. However, a sustained in situ ocean observing system in the tropical North Atlantic Ocean and Caribbean Sea dedicated to measuring subsurface density (thermal and salinity) fields in support of TC intensity studies and forecasts has yet to be designed and implemented. We highlight here current efforts to implement and maintain a suite of observational efforts that utilize data from satellite and autonomous platforms to better understand air-sea processes during high wind events. The example presented here corresponds to the joint use of underwater gliders and satellite altimetry, which have shown to improve the correct representation of ocean conditions and improved forecast for the Hurricane Gonzalo (2014). The impact study carried out for Hurricane Gonzalo (2014) showed that ocean observations helped reduced the error in intensity forecast by almost 50%. Observing System Experiments will be critical to assess the impact of different observing systems, including satellite altimetry and autonomous platforms, in hurricane intensity forecasts.