Proshutinsky, A., Krishfield, R., Toole, J. M., Timmermans, M. - L., Williams, W., Zimmermann, S., et al. (2019). Analysis of the Beaufort Gyre Freshwater Content in 2003-2018. J Geophys Res Oceans, 124(12), 9658–9689.
Abstract: Hydrographic data collected from research cruises, bottom-anchored moorings, drifting Ice-Tethered Profilers, and satellite altimetry in the Beaufort Gyre region of the Arctic Ocean document an increase of more than 6,400 km(3) of liquid freshwater content from 2003 to 2018: a 40% growth relative to the climatology of the 1970s. This fresh water accumulation is shown to result from persistent anticyclonic atmospheric wind forcing (1997-2018) accompanied by sea ice melt, a wind-forced redirection of Mackenzie River discharge from predominantly eastward to westward flow, and a contribution of low salinity waters of Pacific Ocean origin via Bering Strait. Despite significant uncertainties in the different observations, this study has demonstrated the synergistic value of having multiple diverse datasets to obtain a more comprehensive understanding of Beaufort Gyre freshwater content variability. For example, Beaufort Gyre Observational System (BGOS) surveys clearly show the interannual increase in freshwater content, but without satellite or Ice-Tethered Profiler measurements, it is not possible to resolve the seasonal cycle of freshwater content, which in fact is larger than the year-to-year variability, or the more subtle interannual variations.
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Rahaman, H., Srinivasu, U., Panickal, S., Durgadoo, J. V., Griffies, S. M., Ravichandran, M., et al. (2020). An assessment of the Indian Ocean mean state and seasonal cycle in a suite of interannual CORE-II simulations. Ocean Modelling, 145.
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Raulerson, A. E., Arguez, A., O'Brien, J. J., & Smith, S. R. (2005). Interannual to interdecadal surface temperature variability of Florida. In 15th Conference on Applied Climatology, American Meteorological Society, Savannah, Georgia, USA.
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Roads, J. (2003). International Research Institute/Applied Research Centers (IRI/ARCs) regional model intercomparison over South America. J. Geophys. Res., 108(D14).
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Roberts, M. J., Jackson, L. C., Roberts, C. D., Meccia, V., Docquier, D., Koenigk, T., et al. (2020). Sensitivity of the Atlantic Meridional Overturning Circulation to Model Resolution in CMIP6 HighResMIP Simulations and Implications for Future Changes. J. Adv. Model. Earth Syst., , Accepted.
Abstract: A multi‐model, multi‐resolution ensemble using CMIP6 HighResMIP coupled experiments is used to assess the performance of key aspects of the North Atlantic circulation. The Atlantic Meridional Overturning Circulation (AMOC), and related heat transport, tends to become stronger as ocean model resolution is enhanced, better agreeing with observations at 26.5°N. However for most models the circulation remains too shallow compared to observations, and has a smaller temperature contrast between the northward and southward limbs of the AMOC. These biases cause the northward heat transport to be systematically too low for a given overturning strength. The higher resolution models also tend to have too much deep mixing in the subpolar gyre.
In the period 2015‐2050 the overturning circulation tends to decline more rapidly in the higher resolution models, which is related to both the mean state and to the subpolar gyre contribution to deep water formation. The main part of the decline comes from the Florida Current component of the circulation. Such large declines in AMOC are not seen in the models with resolutions more typically used for climate studies, suggesting an enhanced risk for Northern Hemisphere climate change. However, only a small number of different ocean models are included in the study.
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Robinson, W., Speich, S., & Chassignet, E. (2018). Exploring the Interplay Between Ocean Eddies and the Atmosphere. Eos, 99.
Abstract: Climate models, for the first time, have sufficient resolution to capture mesoscale ocean eddies and their interactions with the atmosphere.New model results suggest that the atmosphere, at weather scales or larger, responds to cumulative effects of the much smaller ocean eddies. Intriguing new model results presented at the workshop suggested that the atmosphere, at weather scales or larger.
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Rodríguez, E., Bourassa, M., Chelton, D., Farrar, J. T., Long, D., Perkovic-Martin, D., et al. (2019). The Winds and Currents Mission Concept. Front. Mar. Sci., 6.
Abstract: The Winds and Currents Mission (WaCM) is a proposed approach to meet the need identified by the NRC Decadal Survey for the simultaneous measurements of ocean vector winds and currents. WaCM features a Ka-band pencil-beam Doppler scatterometer able to map ocean winds and currents globally. We review the principles behind the WaCM measurement and the requirements driving the mission. We then present an overview of the WaCM observatory and tie its capabilities to other OceanObs reviews and measurement approaches.
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Salapata, D., Higgins, W., Schemn, J., & O'Brien, J. J. (2002). Winter Temperature and Precipitation Verification of the NCEP Operational Climate Model. COAPS Technical Report 02-04b. Tallahassee, FL: Center for Ocean-Atmospheric Prediction Studies, Florida State University.
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Savage, A. C., Arbic, B. K., Alford, M. H., Ansong, J. K., Farrar, J. T., Menemenlis, D., et al. (2017). Spectral decomposition of internal gravity wave sea surface height in global models: INTERNAL GRAVITY WAVE SEA SURFACE HEIGHT. J. Geophys. Res. Oceans, 122(10), 7803–7821.
Abstract: Two global ocean models ranging in horizontal resolution from 1/128 to 1/488 are used to study the space and time scales of sea surface height (SSH) signals associated with internal gravity waves (IGWs). Frequency-horizontal wavenumber SSH spectral densities are computed over seven regions of the world ocean from two simulations of the HYbrid Coordinate Ocean Model (HYCOM) and three simulations of the Massachusetts Institute of Technology general circulation model (MITgcm). High wavenumber, high-frequency SSH variance follows the predicted IGW linear dispersion curves. The realism of high-frequency motions (>0:87 cpd) in the models is tested through comparison of the frequency spectral density of dynamic height variance computed from the highest-resolution runs of each model (1/258 HYCOM and 1/488 MITgcm) with dynamic height variance frequency spectral density computed from nine in situ profiling instruments. These high-frequency motions are of particular interest because of their contributions to the small-scale SSH variability that will be observed on a global scale in the upcoming Surface Water and Ocean Topography (SWOT) satellite altimetry mission. The variance at supertidal frequencies can be comparable to the tidal and low-frequency variance for high wavenumbers (length scales smaller than 50 km), especially in the higher-resolution simulations. In the highest-resolution simulations, the high-frequency variance can be greater than the low-frequency variance at these scales.
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Sharp, R. J., Bourassa, M. A., & O'Brien, J. J. (2003). Tropical cyclogenesis detection in the East Pacific Hurricane Basin (J. Cote, Ed.). CAS/JSC Working Group on Numerical Experimentation, Research Activities in Atmospheric and Oceanic Modeling. Geneva, Switzerland: World Meteorological Organization.
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