scholarly journals Surface Current Patterns in the Northeastern Chukchi Sea and Their Response to Wind Forcing

2017 ◽  
Vol 122 (12) ◽  
pp. 9530-9547 ◽  
Author(s):  
Ying‐Chih Fang ◽  
Rachel A. Potter ◽  
Hank Statscewich ◽  
Thomas J. Weingartner ◽  
Peter Winsor ◽  
...  
2015 ◽  
Vol 20 (1) ◽  
pp. 115-131 ◽  
Author(s):  
Ivica Vilibić ◽  
Hrvoje Kalinić ◽  
Hrvoje Mihanović ◽  
Simone Cosoli ◽  
Martina Tudor ◽  
...  

2020 ◽  
Vol 8 (11) ◽  
pp. 931
Author(s):  
Syeda Rafiq ◽  
Charitha Pattiaratchi ◽  
Ivica Janeković

The land–sea breeze (LSB) system, driven by the thermal contrast between the land and the adjacent ocean is a widely known atmospheric phenomenon, which occurs in coastal regions globally. South-west Australia experiences a persistent and one of the strongest LSB systems globally with maximum wind speeds associated with the LSB system often exceeding 15 ms−1. In this paper, using field measurements and numerical simulations, we examine: (1) the local winds associated with the land–sea breeze with an emphasis on the ocean; and, (2) the response of the surface currents to the diurnal wind forcing. The measurements indicated that the wind speeds decreased between midnight and 0400 and increased rapidly after 1100, reaching maxima >10 ms−1 around 1800) associated with the sea breeze and decreased to midnight. Wind directions were such that they were blowing from south-east (120°) in the morning and changed to almost southerly (~200°) in the afternoon. Decomposition of the wind record to the diurnal and synoptic components indicated that the diurnal component of winds (i.e., LSB) was oriented along the south-west to north-east axis. However, the stronger synoptic winds were from the south-east to south quadrant and in combination with the LSB, the winds consisted of a strong southerly component. We examined the evolution, horizontal extent, and propagation properties of sea breeze fronts for characteristic LSB cycles and the sea breeze cell propagating offshore and inland. The results indicated that the sea breeze cell was initiated in the morning in a small area, close to 33° S, 115.5° E, with a width of ~25 km and expanded onshore, offshore and alongshore. The sea breeze cell expanded faster (30 kmh−1) and farther (120 km) in the offshore direction than in the onshore direction (10 kmh−1 and 30–40 km). Winds during the LSB cycle followed a counterclockwise rotation that was also reflected in the surface currents. The winds and surface currents rotated anticlockwise with the surface currents responding almost instantaneously to changes in wind forcing but were modified by topography. The diurnal surface currents were enhanced due to the resonance between the LSB forcing and the inertial response.


2018 ◽  
Vol 48 (3) ◽  
pp. 723-738 ◽  
Author(s):  
Kai Håkon Christensen ◽  
Ann Kristin Sperrevik ◽  
Göran Broström

AbstractA high-resolution reanalysis of the circulation in the Kattegat and Skagerrak is used to investigate the mechanisms that control the variability in the onset of the Norwegian Coastal Current. In the reanalysis, the authors have used all available in situ and remote sensing observations of salinity and temperature and use surface current observations from two coastal high-frequency radars that were ideally placed to monitor the exchange between the two basins. This study finds a strong correlation between the variability in the wind forcing in the Skagerrak and the transport in the Norwegian Coastal Current through the Torungen–Hirtshals section. Two cases with winds into and out of the Skagerrak are studied in more detail, and the results suggest asymmetries in the forcing mechanisms. For winds out of the Skagerrak, strong outflows of Baltic Sea Water associated with a deflection of the Kattegat–Skagerrak Front may disrupt local processes in the Skagerrak, which is not accounted for in previously published conceptual models for the variability of the coastal currents in this region.


2020 ◽  
Author(s):  
Jingkai Li

<p>The Stokes drift in the marginal ice zones (MIZ) of the Arctic Ocean is modelled by WAVEWATCH III. Applying two viscoelastic and one empirical frequency-dependent wave-ice models, the modelled wave parameters and spectrum are compared with field observations in the Beaufort-Chukchi Sea. Three wave-ice parameterizations show similar abilities to produce the surface Stokes drift estimated from buoy measurements. By using five-year (2015-2019) hindcasted directional spectra of the autumn Arctic, we present and discuss the monthly mean surface Stokes drift (1-10 cm/s), e-folding depth (1-14 m) and vertically integrated transport (0.1-0.4 m2/s) in the marginal ice zones, which are stronger in October than in September. When bulk wave parameters are adopted to estimate the Stokes drift fields, the surface Stokes drift will be underestimated by about 44-59% with mean ice concentration smaller than 60%, and the Stokes e-folding depth will be overestimated by about 1.4 to 5.0 times increasing from the interior to the edge of the ice cover. Since the Stokes drift may be an important component of the total surface current, we compare the modelled surface Stokes drift with the Eulerian current from reanalysis data, which shows that the mean surface Stokes drift is typically about 30% of the Eulerian current over large parts of the MIZ in Arctic Ocean, and is of the same order or even larger in some sea areas of the Chukchi, E. Siberian and Laptev Seas. It indicates that the Stokes drift is necessary to be considered to better model the dynamic processes of the sea ice, especially for the drift of ice floes.</p>


2018 ◽  
Vol 2 (2) ◽  
pp. 57-65 ◽  
Author(s):  
Mohammad Pakhirehzan ◽  
Maryam Rahbani ◽  
Hossein Malakooti ◽  
◽  
◽  
...  

2018 ◽  
Vol 48 (4) ◽  
pp. 795-805 ◽  
Author(s):  
Gianluca Meneghello ◽  
John Marshall ◽  
Mary-Louise Timmermans ◽  
Jeffery Scott

AbstractWe present observational estimates of Ekman pumping in the Beaufort Gyre region. Averaged over the Canada Basin, the results show a 2003–14 average of 2.3 m yr−1 downward with strong seasonal and interannual variability superimposed: monthly and yearly means range from 30 m yr−1 downward to 10 m yr−1 upward. A clear, seasonal cycle is evident with intense downwelling in autumn and upwelling during the winter months, despite the wind forcing being downwelling favorable year-round. Wintertime upwelling is associated with friction between the large-scale Beaufort Gyre ocean circulation and the surface ice pack and contrasts with previous estimates of yearlong downwelling; as a consequence, the yearly cumulative Ekman pumping over the gyre is significantly reduced. The spatial distribution of Ekman pumping is also modified, with the Beaufort Gyre region showing alternating, moderate upwelling and downwelling, while a more intense, yearlong downwelling averaging 18 m yr−1 is identified in the northern Chukchi Sea region. Implications of the results for understanding Arctic Ocean dynamics and change are discussed.


2020 ◽  
Vol 91 (3) ◽  
pp. 30901
Author(s):  
Yibo Tang ◽  
Longhui He ◽  
Jianming Xu ◽  
Hailang He ◽  
Yuhan Li ◽  
...  

A dual-band microwave metamaterial absorber with single-peak regulation and wide-angle absorption has been proposed and illustrated. The designed metamaterial absorber is consisted of hollow-cross resonators, solid-cross resonators, dielectric substrate and metallic background plane. Strong absorption peak coefficients of 99.92% and 99.55% are achieved at 8.42 and 11.31 GHz, respectively, which is basically consistent with the experimental results. Surface current density and changing material properties are employed to illustrate the absorptive mechanism. More importantly, the proposed dual-band metamaterial absorber has the adjustable property of single absorption peak and could operate well at wide incidence angles for both transverse electric (TE) and transverse magnetic (TM) waves. Research results could provide and enrich instructive guidances for realizing a single-peak-regulation and wide-angle dual-band metamaterial absorber.


2018 ◽  
Vol 44 (1) ◽  
pp. 7-12
Author(s):  
Amy L. Willoughby ◽  
Megan C. Ferguson ◽  
Janet T. Clarke ◽  
Amelia A. Brower

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