Implementation of the Ensemble Kalman Filter into a Northwest Pacific Ocean Circulation Model

2009 ◽  
pp. 341-351 ◽  
Author(s):  
Gwang-Ho Seo ◽  
Sangil Kim ◽  
Byoung-Ju Choi ◽  
Yang-Ki Cho ◽  
Young-Ho Kim
Keyword(s):  
Kalman Filter ◽  
Pacific Ocean ◽  
Ocean Circulation ◽  
Ensemble Kalman Filter ◽  
Circulation Model ◽  
Northwest Pacific ◽  
Ocean Circulation Model ◽  
Northwest Pacific Ocean

scholarly journals Investigation of the Internal Tides in the Northwest Pacific Ocean Considering the Background Circulation and Stratification

2020 ◽  
Vol 50 (11) ◽  
pp. 3165-3188
Author(s):  
Pengyang Song ◽  
Xueen Chen
Keyword(s):  
Pacific Ocean ◽  
Ocean Circulation ◽  
Conversion Rate ◽  
Internal Tide ◽  
Internal Tides ◽  
Global Ocean ◽  
Northwest Pacific ◽  
Northwest Pacific Ocean ◽  
Baroclinic Tide ◽  
The Northwest Pacific Ocean

AbstractA global ocean circulation and tide model with nonuniform resolution is used in this work to resolve the ocean circulation globally as well as mesoscale eddies and internal tides regionally. Focusing on the northwest Pacific Ocean (NWP, 0°–35°N, 105°–150°E), a realistic experiment is conducted to simulate internal tides considering the background circulation and stratification. To investigate the influence of a background field on the generation and propagation of internal tides, idealized cases with horizontally homogeneous stratification and zero surface fluxes are also implemented for comparison. By comparing the realistic cases with idealized ones, the astronomical tidal forcing is found to be the dominant factor influencing the internal tide conversion rate magnitude, whereas the stratification acts as a secondary factor. However, stratification deviations in different areas can lead to an error exceeding 30% in the local internal tide energy conversion rate, indicating the necessity of a realistic stratification setting for simulating the entire NWP. The background shear is found to refract propagating diurnal internal tides by changing the effective Coriolis frequencies and phase speeds, while the Doppler-shifting effect is remarkable for introducing biases to semidiurnal results. In addition, nonlinear baroclinic tide energy equations considering the background circulation and stratification are derived and diagnosed in this work. The mean flow–baroclinic tide interaction and nonlinear energy flux are the most significant nonlinear terms in the derived equations, and nonlinearity is estimated to contribute approximately 5% of the total internal tide energy in the greater Luzon Strait area.

scholarly journals Arrival of the Fukushima radioactivity plume in North American continental waters

2014 ◽  
Vol 112 (5) ◽  
pp. 1310-1315 ◽  
Author(s):  
John N. Smith ◽  
Robin M. Brown ◽  
William J. Williams ◽  
Marie Robert ◽  
Richard Nelson ◽  
...  
Keyword(s):  
Ocean Circulation ◽  
North American ◽  
North Pacific ◽  
Nuclear Reactor ◽  
Circulation Model ◽  
Ocean Current ◽  
Northwest Pacific ◽  
Reactor Accident ◽  
Northwest Pacific Ocean ◽  
The North

The large discharge of radioactivity into the northwest Pacific Ocean from the 2011 Fukushima Dai-ichi nuclear reactor accident has generated considerable concern about the spread of this material across the ocean to North America. We report here the first systematic study to our knowledge of the transport of the Fukushima marine radioactivity signal to the eastern North Pacific. Time series measurements of 134Cs and 137Cs in seawater revealed the initial arrival of the Fukushima signal by ocean current transport at a location 1,500 km west of British Columbia, Canada, in June 2012, about 1.3 y after the accident. By June 2013, the Fukushima signal had spread onto the Canadian continental shelf, and by February 2014, it had increased to a value of 2 Bq/m3 throughout the upper 150 m of the water column, resulting in an overall doubling of the fallout background from atmospheric nuclear weapons tests. Ocean circulation model estimates that are in reasonable agreement with our measured values indicate that future total levels of 137Cs (Fukushima-derived plus fallout 137Cs) off the North American coast will likely attain maximum values in the 3–5 Bq/m3 range by 2015–2016 before declining to levels closer to the fallout background of about 1 Bq/m3 by 2021. The increase in 137Cs levels in the eastern North Pacific from Fukushima inputs will probably return eastern North Pacific concentrations to the fallout levels that prevailed during the 1980s but does not represent a threat to human health or the environment.

Argo data assimilation in ocean general circulation model of Northwest Pacific Ocean

2012 ◽  
Vol 62 (7) ◽  
pp. 1059-1071 ◽  
Author(s):  
Xunqiang Yin ◽  
Fangli Qiao ◽  
Yongzeng Yang ◽  
Changshui Xia ◽  
Xianyao Chen
Keyword(s):  
Pacific Ocean ◽  
Data Assimilation ◽  
General Circulation Model ◽  
General Circulation ◽  
Circulation Model ◽  
Ocean General Circulation Model ◽  
Northwest Pacific ◽  
Argo Data ◽  
Northwest Pacific Ocean ◽  
Ocean General Circulation

scholarly journals Aerosol iron and aluminum solubility in the northwest Pacific Ocean: Results from the 2002 IOC cruise

2006 ◽  
Vol 7 (4) ◽  
pp. n/a-n/a ◽  
Author(s):  
Clifton S. Buck ◽  
William M. Landing ◽  
Joseph A. Resing ◽  
Geoffrey T. Lebon
Keyword(s):  
Pacific Ocean ◽  
Northwest Pacific ◽  
Northwest Pacific Ocean ◽  
The Northwest Pacific Ocean ◽  
Aluminum Solubility

scholarly journals Analysis of Atmospheric and Ionospheric Variations Due to Impacts of Super Typhoon Mangkhut (1822) in the Northwest Pacific Ocean

2021 ◽  
Vol 13 (4) ◽  
pp. 661
Author(s):  
Mohamed Freeshah ◽  
Xiaohong Zhang ◽  
Erman Şentürk ◽  
Muhammad Arqim Adil ◽  
B. G. Mousa ◽  
...  
Keyword(s):  
Wind Speed ◽  
Pacific Ocean ◽  
Tropical Cyclone ◽  
Sea Level ◽  
Northwest Pacific ◽  
Northwest Pacific Ocean ◽  
Sea Level Pressure ◽  
Level Pressure ◽  
Super Typhoon ◽  
The Northwest Pacific Ocean

The Northwest Pacific Ocean (NWP) is one of the most vulnerable regions that has been hit by typhoons. In September 2018, Mangkhut was the 22nd Tropical Cyclone (TC) over the NWP regions (so, the event was numbered as 1822). In this paper, we investigated the highest amplitude ionospheric variations, along with the atmospheric anomalies, such as the sea-level pressure, Mangkhut’s cloud system, and the meridional and zonal wind during the typhoon. Regional Ionosphere Maps (RIMs) were created through the Hong Kong Continuously Operating Reference Stations (HKCORS) and International GNSS Service (IGS) data around the area of Mangkhut typhoon. RIMs were utilized to analyze the ionospheric Total Electron Content (TEC) response over the maximum wind speed points (maximum spots) under the meticulous observations of the solar-terrestrial environment and geomagnetic storm indices. Ionospheric vertical TEC (VTEC) time sequences over the maximum spots are detected by three methods: interquartile range method (IQR), enhanced average difference (EAD), and range of ten days (RTD) during the super typhoon Mangkhut. The research findings indicated significant ionospheric variations over the maximum spots during this powerful tropical cyclone within a few hours before the extreme wind speed. Moreover, the ionosphere showed a positive response where the maximum VTEC amplitude variations coincided with the cyclone rainbands or typhoon edges rather than the center of the storm. The sea-level pressure tends to decrease around the typhoon periphery, and the highest ionospheric VTEC amplitude was observed when the low-pressure cell covers the largest area. The possible mechanism of the ionospheric response is based on strong convective cells that create the gravity waves over tropical cyclones. Moreover, the critical change state in the meridional wind happened on the same day of maximum ionospheric variations on the 256th day of the year (DOY 256). This comprehensive analysis suggests that the meridional winds and their resulting waves may contribute in one way or another to upper atmosphere-ionosphere coupling.

scholarly journals Differences in cell viabilities of phytoplankton between spring and late summer in the northwest Pacific Ocean

2008 ◽  
Vol 360 (2) ◽  
pp. 63-70 ◽  
Author(s):  
Maki Hayakawa ◽  
Koji Suzuki ◽  
Hiroaki Saito ◽  
Kazutaka Takahashi ◽  
Shin-ichi Ito
Keyword(s):  
Pacific Ocean ◽  
Late Summer ◽  
Northwest Pacific ◽  
Northwest Pacific Ocean ◽  
The Northwest Pacific Ocean
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