Ocean Climate Shift Derived from Northwest Atlantic Regional Climatology
Abstract
The Northwest Atlantic (NWA) is one of the key regions of the World Ocean where ocean climate change may be critical for the Atlantic Meridional Overturning Circulation. Therefore additional efforts are required to assess thermohaline structure and variability in this region. In support of such efforts, Regional Climatology Team at the National Centers for Environmental Information developed a new Northwest Atlantic Regional Climatology (NWARC). It comprises a set of annual, seasonal, and monthly mean temperature and salinity fields for six decades from 1955 to 2012 on one-, quarter- and one-tenth-degree grids. Using the decadal temperature fields from NWARC, we computed ocean heat content (OHC) of the upper 700- meter layer for two 30-year periods of 1955 - 1984 and 1985 - 2012. Comparison of these fields showed substantial warming of the water south of the Gulf Stream and in the Labrador Sea. Although there are some areas with noticeable decreases in OHC, distinct overall warming in the NWA region is evident. In support of the OHC analysis, the 30- and 60-year trends of upper ocean temperature were computed using pentadal sliding averages, which confirmed the results of the climatic shift in the OHC, compiled using NWARC. The one-tenth-degree resolution fields reveal more fine-scale structures that may be expected to match the fields obtained in present-day eddy-resolving ocean models. To verify this contention we show preliminary results of a direct comparison between the NWARC and the modeled ocean climatologies derived from NEMO (Nucleus for European Modelling of the Ocean) eddy-resolving simulations.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.A23G0295M
- Keywords:
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- 3305 Climate change and variability;
- ATMOSPHERIC PROCESSESDE: 0402 Agricultural systems;
- BIOGEOSCIENCESDE: 1622 Earth system modeling;
- GLOBAL CHANGEDE: 4215 Climate and interannual variability;
- OCEANOGRAPHY: GENERAL