A5077733164- Oceanographic and Atmospheric Processes
- Climate variability and models
- Arctic and Antarctic ice dynamics
- Tropical and Extratropical Cyclones Research
- Ocean Waves and Remote Sensing
- Marine and coastal ecosystems
- Meteorological Phenomena and Simulations
- Geology and Paleoclimatology Research
- Marine and fisheries research
- Atmospheric aerosols and clouds
- Methane Hydrates and Related Phenomena
- Ionosphere and magnetosphere dynamics
- Atmospheric Ozone and Climate
- Ocean Acidification Effects and Responses
- Fluid Dynamics Simulations and Interactions
- Coastal and Marine Dynamics
- Underwater Acoustics Research
- Indoor Air Quality and Microbial Exposure
- Food Industry and Aquatic Biology
- Geological and Geophysical Studies
- Maritime Navigation and Safety
- Urban and Freight Transport Logistics
- Solar Radiation and Photovoltaics
- Radioactive contamination and transfer
- Isotope Analysis in Ecology
Japan Agency for Marine-Earth Science and Technology
2013-2024
Nihon University
2009-2016
College of Industrial Technology
2016
Tohoku University
2000-2006
Scripps Institution of Oceanography
2004
Kanazawa Institute of Technology
1991
Recent observational surveys have shown significant oceanic bottom-water warming. However, the mechanisms causing such warming remain poorly understood, and their time scales are uncertain. Here, we report computer simulations that reveal a fast teleconnection between changes in surface air-sea heat flux off Adélie Coast of Antarctica North Pacific. In contrast to conventional estimates multicentennial scale, this link is established over only four decades through action internal waves....
[1] We calculated basin-scale and global ocean decadal temperature change rates from the 1990s to 2000s for waters below 3000 m. Large increases were detected around Antarctica, a relatively large increase was along northward path of Circumpolar Deep Water in Pacific. The heat content (HC) estimated m 0.8 × 1022 J decade−1; value that cannot be neglected precise estimation balance. We reproduced observed changes deep using data assimilation system examined virtual observations field evaluate...
[1] The Kuroshio Extension Observatory (KEO) is a highly instrumented moored reference station located at 32.3°N, 144.5°E in the recirculation gyre south of Extension. On 19 September 2009, eye Typhoon Choi-Wan (International designation: 0914) passed ∼40 km to southeast KEO surface mooring. Hourly meteorological and physical oceanographic measurements together with 3 hourly air-sea carbon dioxide observations telemetered from near real time show evolution upper ocean its associated fluxes...
Abstract Airborne bacteria have been shown to act as condensation and ice nuclei in mixed‐phase clouds are consequently hypothesized significant effects on atmospheric processes even the global climate. However, few data available regarding their concentration variation air over open ocean. Aerosol samples were collected during three cruises early summers of 2013, 2014, 2016 Kuroshio Extension region northwest Pacific Ocean. The concentrations viable nonviable bacterial cells marine surface...
In 2014, we measured activity concentration of radiocesium in the western North Pacific Ocean. north Kuroshio Front high Fukushima-derived surface mixed layer 2012 had been transported eastward by 2014. south front found a subsurface maximum 200-600 m depth, which was similar to that observed 2012. The spread southward from 18°N 15°N between and suggests spreading into whole subtropical area 2014 due formation subduction mode water.
We have produced global daily high‐resolution analytical sea surface temperature (SST) data for the latter half of 1990s from four kinds different satellite SST products, including microwave SST, 1998. The optimum interpolation (OI) method is applied to anomaly climatological annual signal with decorrelation scales first‐guess error less than 200 km. effective spatial resolution OI a few hundred kilometers due these scales. monthly mean difference between this and in situ averaged 60°S–60°N...
Point-positioning GPS-based wave measurements were conducted by deep ocean (over 5,000 m) surface buoys moored in the North West Pacific Ocean 2009, 2012, and 2013. The observed elevation bears statistical characteristics of Gaussian, spectrally narrow waves. tail averaged spectrum follows frequency to power −4 slope, significant height period satisfies Toba's 3/2 law. observations compare well with a numerical hindcast. Two large freak waves exceeding 13 m October 2009 three extreme around...
Several research cruises were conducted across the Kuroshio Extension front to examine low-level atmospheric responses mesoscale variations in sea surface temperature (SST). Surface meteorological observations, including level pressure (SLP) and SST, collected at two moored buoys that located on either side of Extension, from a vessel, as it moved between during various cruises. Spatial perturbations SLP along ship transects, calculated by subtracting moored-buoy moving ship, tend be...
We investigated the impact of wave-ocean interaction on numerical predictions for Typhoon Hai-Tang in 2005 using a nonhydrostatic atmosphere model coupled with third-generation ocean wave and mixed-layer model. Here we address effect breaking surface waves entrainment induced at base, assuming that turbulent transport due to is expressed as function both wave-induced wind stresses. The introduction into enables us reproduce evolution Hai-Tang's central pressure sea-surface temperature (SST)...
Using advance satellite‐derived sea surface temperature (SST), solar radiation and wind speed products, we investigate hot events (HEs) associated with very high SST of around 30°C. Amplitude the diurnal variation (DSST) is obtained by an empirical formula downward shortwave (DSSR) speed. The HE defined as a connected region > time‐dependent threshold about 30°C having minimum areal size greater than 3 × 10 6 km 2 lasting for period longer days. Thirty‐one were detected from 1993 to 2003...
Abstract. To assess the differences between RS92 radiosonde and its improved counterpart, Vaisala RS41-SGP version with a pressure sensor, 36 twin-radiosonde launches were made over Arctic Ocean, Bering Sea, western North Pacific tropical Indian Ocean during two cruises of R/V Mirai in 2015. The biases, standard deviations, root mean squares (rms's) RS41 data all flights altitudes smaller than nominal combined uncertainties RS41, except that rms above 100 exceeded 0.6 hPa. A comparison...
On 19 September 2009, Typhoon Choi‐wan passed ∼40 km to the southeast of Kuroshio Extension Observatory (KEO) surface mooring, located at 32.3°N, 144.5°E. We use an atmosphere‐wave‐ocean coupled model that incorporated oceanic carbon equilibrium investigate typhoon‐induced CO 2 outgassing observed by KEO mooring. data are used provide atmospheric boundary conditions for partial pressure ( ) and validate numerical results. The simulated sea‐level variations reasonably well, although...
Abstract We performed a comprehensive analysis of satellite chlorophyll-a concentration (chl-a) data to detect all events in which chl-a rapidly increased on time scale 10 days or less. Our could successfully cases and sea surface temperature (SST) decreased after the passages tropical extratropical cyclones. The with large SST decreases tended occur south Japan, Sea Okhotsk, regions between 35° 45° N, especially Kuroshio–Oyashio Extension (KOE) region. Although contribution cyclones yearly...
From the moored buoy observation at $$33.9^{\circ }$$ N, $$144.9^{\circ E south of Kuroshio Extension (KE), we obtained Eulerian time series dissolved oxygen concentration (DO) 200, 400, and 600 m depths from June 2012 to March 2013. We observed ventilation by meso- submesoscale processes that transport water southward across KE jet. First, cyclonic mesoscale eddy in substantially depressed DO 400 but maintained 200 m, suggesting near-surface lateral high-DO derived north KE. Second,...
Abstract Interannual variations in upper ocean salinity the North Pacific Ocean (NP) were examined comprehensively over a period of 18 years (2004–2021) with gridded data sets considering vertical profiles salinity. The nearly half basin varied phase slight lag, and rest exhibited opposite on decadal scale. average above 400 dbar prominently increased eastern western mid‐latitude regions from approximately 2010 to latter 2010s, decreased central subarctic subtropics during same period. This...