Northwest Atlantic regional ocean climatology.

• Main Author: Seidov, Dan, 1948-
• Format: Text
• Language: English
• Published: U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Environmental Satellite, Data, and Information Service, National Centers for Environmental Information 2016
• Subjects: Ocean currents > North Atlantic Ocean.; north atlantic current; North Atlantic; Northwest Atlantic
• Online Access: https://dx.doi.org/10.7289/v5/atlas-nesdis-80; https://repository.library.noaa.gov/view/noaa/12209

The Northwest Atlantic Ocean (NWA) plays a crucial role in global climate change. The Gulf Stream and North Atlantic Current System are the key elements of northward heat transport and the Meridional Overturning Circulation in the North Atlantic Ocean. The NWA includes a resource-rich coastal zone with abundant fisheries and other natural resources. Its economic significance and climatic importance resulted in many observational and research programs spanning over many decades. To provide a more solid and improved oceanographic foundation and reference for multidisciplinary studies of the NWA, the Regional Climatology Team at the National Centers for Environmental Information (NCEI), formerly the National Oceanographic Data Center (NODC) in Silver Spring, Maryland, USA, developed a new set of high-resolution, qualitycontrolled, long-term annual, seasonal, and monthly mean temperature and salinity fields at different depth levels in the NWA region. This new regional climatology is based on the temperature and salinity profiles from oceanographic in situ observations spanning more than one hundred years archived in the World Ocean Database (WOD). When computing anomalies from a climatology, i.e., from the temperature and salinity fields averaged over several decades, the mesoscale field is smoothed to prevent generation of spurious anomalies. The smoothing depends on the spatial grid resolution and thus can cause differences in climatological fields because of smoothing. On finer resolution grids with lesser smoothing, climatic residual of mesoscale eddies with spatial scale longer than grid cell sizes can be directly resolved and the remaining mesoscale background presumably represents the cumulative effect of mesoscale dynamics rather than a noise caused by objective analysis. The advantage of high-resolution analysis becomes obvious as the use of shorter influence radii in the objective interpolation procedure leads to less smoothing in the region of sharp frontal zones, especially in the coastal regions. In a sense, the finer-resolution analysis pursues the same goal as using progressively reduced grid sizes did in making headway from coarse-resolution to eddy-permitting and then to eddy-resolving numerical models of ocean circulation. The high-resolution regional climatologies are closing the gaps between observations and model simulations, which allows meaningful data-model comparisons in critical data-rich regions, such as the NWA.