scholarly journals Steric Sea Level Change in the Northern Seas

2007 ◽  
Vol 20 (3) ◽  
pp. 403-417 ◽  
Author(s):  
Michael Steele ◽  
Wendy Ermold
Keyword(s):  
Arctic Ocean ◽  
Sea Level ◽  
North Atlantic ◽  
North Pacific ◽  
North Atlantic Ocean ◽  
North Pacific Ocean ◽  
Steric Height ◽  
The North ◽  
Flow Through ◽  
The North Atlantic

Abstract Ocean temperature and salinity data over the period 1950–2000 in the Northern Seas, defined here as the North Atlantic Ocean (north of 50°N), North Pacific Ocean (north of 40°N), and Arctic Oceans, are combined to diagnose the steric (i.e., density) contribution to sea level variation. The individual contributions to steric height from temperature (thermosteric height) and salinity (halosteric height) are also analyzed. It is found that during 1950–2000, steric height rose over the study’s domain, mostly as a result of halosteric increases (i.e., freshening). Over a shorter time period (late 1960s to early 1990s) during which climate indices changed dramatically, steric height gradients near the Nordic Seas minimum were reduced by 18%–32%. It is speculated that this may be associated with a local slowing of both the Meridional Overturning Circulation and the southward flow through Fram Strait. However, steric height increases in the North Pacific Ocean during this time imply a possible acceleration of flow through the poorly measured Canadian Arctic. Evidence that the Great Salinity Anomaly of the late 1960s and 1970s had two distinct Arctic Ocean sources is also found: a late 1960s export of sea ice, and a delayed but more sustained 1970s export of liquid (ocean) freshwater. A simple calculation indicates that these Arctic Ocean freshwater sources were not sufficient to create the 1970s freshening observed in the North Atlantic Ocean.

Satellite-Derived Tropical Cyclone Intensity in the North Pacific Ocean Using the Deviation-Angle Variance Technique

2014 ◽  
Vol 29 (3) ◽  
pp. 505-516 ◽  
Author(s):  
Elizabeth A. Ritchie ◽  
Kimberly M. Wood ◽  
Oscar G. Rodríguez-Herrera ◽  
Miguel F. Piñeros ◽  
J. Scott Tyo
Keyword(s):  
Tropical Cyclone ◽  
North Atlantic ◽  
North Pacific ◽  
Western North Pacific ◽  
North Pacific Ocean ◽  
Deviation Angle ◽  
Intensity Estimation ◽  
The North ◽  
The North Atlantic ◽  
The North Pacific

Abstract The deviation-angle variance technique (DAV-T), which was introduced in the North Atlantic basin for tropical cyclone (TC) intensity estimation, is adapted for use in the North Pacific Ocean using the “best-track center” application of the DAV. The adaptations include changes in preprocessing for different data sources [Geostationary Operational Environmental Satellite-East (GOES-E) in the Atlantic, stitched GOES-E–Geostationary Operational Environmental Satellite-West (GOES-W) in the eastern North Pacific, and the Multifunctional Transport Satellite (MTSAT) in the western North Pacific], and retraining the algorithm parameters for different basins. Over the 2007–11 period, DAV-T intensity estimation in the western North Pacific results in a root-mean-square intensity error (RMSE, as measured by the maximum sustained surface winds) of 14.3 kt (1 kt ≈ 0.51 m s−1) when compared to the Joint Typhoon Warning Center best track, utilizing all TCs to train and test the algorithm. The RMSE obtained when testing on an individual year and training with the remaining set lies between 12.9 and 15.1 kt. In the eastern North Pacific the DAV-T produces an RMSE of 13.4 kt utilizing all TCs in 2005–11 when compared with the National Hurricane Center best track. The RMSE for individual years lies between 9.4 and 16.9 kt. The complex environment in the western North Pacific led to an extension to the DAV-T that includes two different radii of computation, producing a parametric surface that relates TC axisymmetry to intensity. The overall RMSE is reduced by an average of 1.3 kt in the western North Pacific and 0.8 kt in the eastern North Pacific. These results for the North Pacific are comparable with previously reported results using the DAV for the North Atlantic basin.

scholarly journals Seasonal Barotropic Modulation of the Deep-Water Overflow through the Faroe Bank Channel

2006 ◽  
Vol 36 (12) ◽  
pp. 2328-2339 ◽  
Author(s):  
Iréne Lake ◽  
Peter Lundberg
Keyword(s):  
North Atlantic ◽  
Deep Water ◽  
Satellite Altimetry ◽  
North Atlantic Ocean ◽  
Norwegian Sea ◽  
The North ◽  
Flow Through ◽  
The North Atlantic ◽  
Water Overflow

Abstract As a joint Nordic project, an upward-looking ADCP has been maintained at the sill of the Faroe Bank Channel from 1995 onward. Records from a period in 1998 with three current meters deployed across the channel were used to demonstrate that the Faroe Bank Channel deep-water transport from the Norwegian Sea into the North Atlantic Ocean proper can be reasonably well estimated from one centrally located ADCP. The long-term average of this transport over the period 1995–2001 was found to be 2.1 Sv (Sv ≡ 106 m−3 s−1). The transport record demonstrates a pronounced seasonality. Satellite altimetry shows that this is caused by the northbound Atlantic surface water inflow giving rise to a barotropic modulation of the deep-water flow through the Faroe–Shetland Channel and the southern reaches of the Norwegian Sea.

Factors influencing trematode parasite burdens in mussels (Mytilus spp) from the north Atlantic ocean across to the north Pacific

2013 ◽  
Vol 132 ◽  
pp. 87-93 ◽  
Author(s):  
J.G. Wilson ◽  
K.V. Galaktionov ◽  
A.A. Sukhotin ◽  
K. Skirnisson ◽  
K.E. Nikolaev ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
North Atlantic ◽  
North Pacific ◽  
North Atlantic Ocean ◽  
Trematode Parasite ◽  
The North ◽  
Factors Influencing ◽  
The North Atlantic ◽  
The North Pacific

scholarly journals An Atlantic-driven rapid circulation change in the North Pacific Ocean during the late 1990s

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Chau-Ron Wu ◽  
Yong-Fu Lin ◽  
You-Lin Wang ◽  
Noel Keenlyside ◽  
Jin-Yi Yu
Keyword(s):  
North Atlantic ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Kuroshio Current ◽  
Climate Trends ◽  
North Pacific Subtropical Gyre ◽  
Inter Tropical Convergence Zone ◽  
The North ◽  
The North Atlantic ◽  
The North Pacific

Abstract Interbasin interactions have been increasingly emphasized in recent years due to their roles in shaping climate trends and the global warming hiatus in the northern hemisphere. The profound influence from the North Atlantic on the Tropical Pacific has been a primary focus. In this study, we conducted observational analyses and numerical modeling experiments to show that the North Atlantic has also strongly influenced the Extratropical North Pacific. A rapid and synchronous change in the atmospheric and oceanic circulations was observed in the North Pacific during the late 1990s. The change was driven by the transbasin influence from the Atlantic Ocean. During the positive phase of the Atlantic Multidecadal Oscillation (AMO) since the 1990s, the anomalously warm North Atlantic triggers a series of zonally symmetric and asymmetric transbasin teleconnections involving the Inter-tropical Convergence Zone (ITCZ), Walker and Hadley circulations, and Rossby wave propagation that lead to a decrease in wind stress curls over the Pacific subtropics, resulting in an abrupt weakening in the North Pacific subtropical gyre (NPSG) and the Kuroshio Current.

Nordic Seas Hydrography in the Context of Arctic and North Atlantic Ocean Dynamics

2021 ◽  
Vol 51 (1) ◽  
pp. 101-114
Author(s):  
J. S. Kenigson ◽  
M.-L. Timmermans
Keyword(s):  
Atlantic Ocean ◽  
Arctic Ocean ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
Ocean Dynamics ◽  
Nordic Seas ◽  
Convective Mixing ◽  
The North ◽  
Unified View ◽  
The North Atlantic

AbstractThe hydrography of the Nordic seas, a critical site for deep convective mixing, is controlled by various processes. On one hand, Arctic Ocean exports are thought to freshen the North Atlantic Ocean and the Nordic seas, as in the Great Salinity Anomalies (GSAs) of the 1970s–1990s. On the other hand, the salinity of the Nordic seas covaries with that of the Atlantic inflow across the Greenland–Scotland Ridge, leaving an uncertain role for Arctic Ocean exports. In this study, multidecadal time series (1950–2018) of the Nordic seas hydrography, Subarctic Front (SAF) in the North Atlantic Ocean [separating the water masses of the relatively cool, fresh Subpolar Gyre (SPG) from the warm, saline Subtropical Gyre (STG)], and atmospheric forcing are examined and suggest a unified view. The Nordic seas freshwater content is shown to covary on decadal time scales with the position of the SAF. When the SPG is strong, the SAF shifts eastward of its mean position, increasing the contribution of subpolar relative to subtropical source water to the Atlantic inflow, and vice versa. This suggests that Arctic Ocean fluxes primarily influence the hydrography of the Nordic seas via indirect means (i.e., by freshening the SPG). Case studies of two years with anomalous NAO conditions illustrate how North Atlantic Ocean dynamics relate to the position of the SAF (as indicated by hydrographic properties and stratification changes in the upper water column), and therefore to the properties of the Atlantic inflow and Nordic seas.

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