The Effect of Measured Whipping and Springing on LNG Vessels

2013 ◽  
Author(s):  
Gaute Storhaug ◽  
Narve Oma ◽  
Bjarne Blomberg ◽  
Kazuhiro Hirota
Keyword(s):  
Fatigue Damage ◽  
North Atlantic ◽  
Wind Waves ◽  
Point Of View ◽  
Strain Sensors ◽  
General Level ◽  
Structural Members ◽  
The North ◽  
The Relationship ◽  
The North Pacific

Strain measurements of structural members onboard two LNG vessels have been collected for a period of 5 years. The vessels have been sailing in the world wide trade except for the North Pacific area. The time spent in the North Atlantic is about 40%, which is higher than for typical LNG vessels. The vessel speed has been relatively low in average and well below the service speed, still the effect of springing and whipping has been significant on the fatigue and extreme loading. Previously, results from the strain sensors have been presented versus the fatigue and extreme loading on a general level, independent on the environmental conditions. In this paper the focus is more towards how the vessel behaves in wind/waves with respect to springing and whipping in order to understand more of the relationship between accumulated fatigue damage, heading and loading condition. The vessels have been equipped with wave radars and wind sensors. The effect of whipping and springing on accumulated or part fatigue damage versus relative heading is demonstrated. The effect as a function of the wave height/wind speed is shown for selected headings. One of the objectives is to check if the wind sensor can be a useful alternative to the wave sensor to capture the physics. Some of the data is studied for ballast and cargo condition separately in order to see if these loading conditions can be merged, which is desirable from an assessment point of view.

The Role of Oscillating Southern Hemisphere Westerly Winds: Global Ocean Circulation

2020 ◽  
Vol 33 (6) ◽  
pp. 2111-2130
Author(s):  
Woo Geun Cheon ◽  
Jong-Seong Kug
Keyword(s):  
Ocean Circulation ◽  
North Atlantic ◽  
North Pacific ◽  
Global Ocean ◽  
The North ◽  
Westerly Winds ◽  
The North Atlantic ◽  
Global Ocean Circulation ◽  
The Antarctic ◽  
The North Pacific

AbstractIn the framework of a sea ice–ocean general circulation model coupled to an energy balance atmospheric model, an intensity oscillation of Southern Hemisphere (SH) westerly winds affects the global ocean circulation via not only the buoyancy-driven teleconnection (BDT) mode but also the Ekman-driven teleconnection (EDT) mode. The BDT mode is activated by the SH air–sea ice–ocean interactions such as polynyas and oceanic convection. The ensuing variation in the Antarctic meridional overturning circulation (MOC) that is indicative of the Antarctic Bottom Water (AABW) formation exerts a significant influence on the abyssal circulation of the globe, particularly the Pacific. This controls the bipolar seesaw balance between deep and bottom waters at the equator. The EDT mode controlled by northward Ekman transport under the oscillating SH westerly winds generates a signal that propagates northward along the upper ocean and passes through the equator. The variation in the western boundary current (WBC) is much stronger in the North Atlantic than in the North Pacific, which appears to be associated with the relatively strong and persistent Mindanao Current (i.e., the southward flowing WBC of the North Pacific tropical gyre). The North Atlantic Deep Water (NADW) formation is controlled by salt advected northward by the North Atlantic WBC.

scholarly journals On the Relationship between Synoptic Wintertime Atmospheric Variability and Path Shifts in the Gulf Stream and the Kuroshio Extension

2009 ◽  
Vol 22 (12) ◽  
pp. 3177-3192 ◽  
Author(s):  
Terrence M. Joyce ◽  
Young-Oh Kwon ◽  
Lisan Yu
Keyword(s):  
North Atlantic ◽  
North Pacific ◽  
Gulf Stream ◽  
Kuroshio Extension ◽  
Storm Track ◽  
Western Boundary ◽  
Atmospheric Variability ◽  
The North ◽  
The Kuroshio ◽  
The North Pacific

Abstract Coherent, large-scale shifts in the paths of the Gulf Stream (GS) and the Kuroshio Extension (KE) occur on interannual to decadal time scales. Attention has usually been drawn to causes for these shifts in the overlying atmosphere, with some built-in delay of up to a few years resulting from propagation of wind-forced variability within the ocean. However, these shifts in the latitudes of separated western boundary currents can cause substantial changes in SST, which may influence the synoptic atmospheric variability with little or no time delay. Various measures of wintertime atmospheric variability in the synoptic band (2–8 days) are examined using a relatively new dataset for air–sea exchange [Objectively Analyzed Air–Sea Fluxes (OAFlux)] and subsurface temperature indices of the Gulf Stream and Kuroshio path that are insulated from direct air–sea exchange, and therefore are preferable to SST. Significant changes are found in the atmospheric variability following changes in the paths of these currents, sometimes in a local fashion such as meridional shifts in measures of local storm tracks, and sometimes in nonlocal, broad regions coincident with and downstream of the oceanic forcing. Differences between the North Pacific (KE) and North Atlantic (GS) may be partly related to the more zonal orientation of the KE and the stronger SST signals of the GS, but could also be due to differences in mean storm-track characteristics over the North Pacific and North Atlantic.

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.

Enhanced warming of the subtropical mode water in the North Pacific and North Atlantic

2017 ◽  
Vol 7 (9) ◽  
pp. 656-658 ◽  
Author(s):  
Shusaku Sugimoto ◽  
Kimio Hanawa ◽  
Tomowo Watanabe ◽  
Toshio Suga ◽  
Shang-Ping Xie
Keyword(s):  
North Atlantic ◽  
North Pacific ◽  
Mode Water ◽  
Subtropical Mode Water ◽  
The North ◽  
The North Pacific

scholarly journals Study on the Association of Casualties and Classification of Heat Wave Weather Patterns in South Korea Using K-Means Clustering Analysis

2020 ◽  
Vol 20 (3) ◽  
pp. 11-18
Author(s):  
Hyeon-Cheol Lee ◽  
Young-Jun Cho ◽  
Byunghwan Lim ◽  
Seung-Bum Kim
Keyword(s):  
South Korea ◽  
Heat Wave ◽  
North Pacific ◽  
Korean Peninsula ◽  
Clustering Analysis ◽  
Weather Patterns ◽  
The North ◽  
The Relationship ◽  
The North Pacific

In this study, weather patterns (WPs) associated with the heat wave in South Korea are objectively classified by applying <i>K</i>-means clustering analysis. The representative weather patterns that caused the heat wave were divided into three WPs, namely WP 1, WP 2, and WP 3. The heat wave over the Korean Peninsula was mainly related to the expansion of the North Pacific High (NPH). Moreover, we analyzed the relationship between casualties and WPs of the heat wave. In WP 1, the isobar of NPH was located in the southern part of South Korea. Most casualties (18 people) occurred in this region. In WP 2, NPH was distributed throughout South Korea, with nationwide casualties of 44 people. Moreover, the duration of the heat wave for WP 2 was the longest, at 4.5 days. WP 3 occurred mainly in June, when the NPH was not yet developed, presenting the smallest number of casualties.

scholarly journals The relationship between Le Van Duyet and Minh Mang in the first 30 years of the power concentration process in the Nguyen Dynasty

2016 ◽  
Vol 19 (2) ◽  
pp. 5-18
Author(s):  
Thuan Tran ◽  
Toan Phuc Vo
Keyword(s):  
Central Government ◽  
Point Of View ◽  
Great Power ◽  
National Defense ◽  
The North ◽  
Political Relations ◽  
Administrative Unit ◽  
Administrative Units ◽  
The Relationship ◽  
North And South

Upon founding the dynasty, Gia Long upheld a politico-military on a vast territory with two administrative units of power ruling over the two areas now named the North and South of Vietnam respectively. Gia Dinh Citadel – the administrative unit ruling the South of Vietnam with a very important role in economy, national defense, and diplomacy – was headed by Le Van Duyet. In the first 30 years of the Nguyen Dynasty, along with the transfer of power from the Gia Long to the Minh Mang was the position assertion of Le Van Duyet in Gia Dinh Citadel, making him one of the most powerful figures. However, the transfer of the throne also marked the concentration of power into the hands of the central government ruled by the emperor; thus, leading to the elimination of administrative units upholding great power such as Gia Dinh Citadel. This process took place in a quite complex manner due to intrinsic problems revolving around the relationship between Minh Mang and Le Van Duyet – the relationship between a king and a high-ranking mandarin with great power. The paper describes the maneuver of political relations between the two characters in the 30 years of power concentration from a fresher point of view.

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