Intercomparison of the Gulf Stream in ocean reanalyses: 1993−2010. (May 2018)

• Record Type: Journal Article
• Authors: Chi, Lequan; Wolfe, Christopher L.P.; Hameed, Sultan
• Is Part Of: Ocean modelling. Volume 125(2018)
• Page Start: 1
• Page End: 21
• Publication Date: 2018-05
• Subjects: North Atlantic Ocean -- Gulf Stream -- Ocean reanalysis -- Intercomparison; Oceanography -- Periodicals; Océanographie -- Périodiques; Oceanography; Periodicals; 551.46
• DOI: 10.1016/j.ocemod.2018.02.008
• Languages: English
• ISSNs: 1463-5003

Abstract

Highlights: The Gulf Stream in several ocean reanalysis products is examined. Velocity structure of the Gulf Stream from New York to Bermuda is discussed. The maximum Gulf Stream velocity is much weaker in reanalyses than in observations. HYCOM and GLORYS2v4 stand out for their superior performance in most metrics. Abstract: In recent years, significant progress has been made in the development of high-resolution ocean reanalysis products. This paper compares aspects of the Gulf Stream (GS) from the Florida Straits to south of the Grand Banks—particularly Florida Strait transport, separation of the GS near Cape Hatteras, GS properties along the Oleander Line (from New Jersey to Bermuda), GS path, and the GS north wall positions—in 13 widely used global reanalysis products of various resolutions, including two unconstrained products. A large spread across reanalysis products is found. HYCOM and GLORYS2v4 stand out for their superior performance by most metrics. Some common biases are found in all discussed models; for example, the velocity structure of the GS near the Oleander Line is too symmetrical and the maximum velocity is too weak compared with observations. Less than half of the reanalysis products show significant correlations (at the 95% confidence level) with observations for the GS separation latitude at Cape Hatteras, the GS transport, and net transport across Oleander Line. The cross-stream velocity structure is further discussed by a theoretical model idealizing GS as a smoothed PV front.