A5040939132- Climate variability and models
- Oceanographic and Atmospheric Processes
- Meteorological Phenomena and Simulations
- Tropical and Extratropical Cyclones Research
- Arctic and Antarctic ice dynamics
- Remote Sensing and Land Use
- Precipitation Measurement and Analysis
- Advanced Computational Techniques and Applications
- Marine and coastal ecosystems
- Semiconductor materials and devices
- Hydrological Forecasting Using AI
- Geology and Paleoclimatology Research
- Ocean Waves and Remote Sensing
- Advancements in Semiconductor Devices and Circuit Design
- Flood Risk Assessment and Management
- Pleistocene-Era Hominins and Archaeology
- Environmental and Agricultural Sciences
- Complex Systems and Time Series Analysis
- Time Series Analysis and Forecasting
- Organic Light-Emitting Diodes Research
- Urban Heat Island Mitigation
- Diverse Interdisciplinary Research Innovations
- Energy and Environmental Systems
- Earthquake Detection and Analysis
- Plant Physiology and Cultivation Studies
Kumamoto University
2014-2024
Osaka University
2019-2022
Osaka Research Institute of Industrial Science and Technology
2022
Graduate School USA
2016
Japan Agency for Marine-Earth Science and Technology
2001-2014
Sanyo (Japan)
2006
United States Global Change Research Program
2000-2002
University of Hawaiʻi at Mānoa
1998-2000
Pacific International Center for High Technology Research
2000
University of Hawaii System
2000
Using the National Centers for Environmental Predictions (NCEP)–National Center Atmospheric Research (NCAR) reanalysis, distributions of heat source Q1 and moisture sink Q2 between 50°N 50°S are determined a 15-yr period from 1980 to 1994. Heating mechanisms operating in various parts world examined by comparing horizontal vertically integrated 〈Q1〉 with those 〈Q2〉 outgoing longwave radiation (OLR) flux vertical Q2. In northern winter, major sources located (i) broad zone connecting tropical...
A 20-year integration by the nonhydrostatic icosahedral atmospheric model (NICAM) with a 14 km mesh was conducted for first time to obtain climatological mean and diurnal interannual variability of simulated atmosphere. Clouds were explicitly calculated using cloud microphysics scheme without cumulus convection scheme. The simulation performed under intercomparison project-type conditions, except that sea surface temperature nudged toward observed historical values slab ocean model. results...
The diagnostic study of the biennial oscillation (BO) ENSO/monsoon system is performed by using sea surface temperature (SST), wind, level pressure, and outgoing longwave radiation data. BO a prominent feature that results in modulation convective activity aroud maritime continent. tends to change its anomalous states during Northern Hemisphere spring. SST variation around South China Sea also has with phase transition occur about half year earlier, is, autumn. intensification northeast...
Baiu is a Japanese name for rain and the rainy season that occurs in boreal early summer western North Pacific (WNP). This work proposes methodology to determine onset closing dates using only an atmospheric parameter, equivalent potential temperature (θe) lower troposphere, reveal interannual variability of season. First, location front determined by maximum negative meridional gradient θe, which identifies zonal boundary air masses. Then, are fixed on basis northward movement development...
Abstract In recent decades, rise of sea surface temperature (SST) in the Kuroshio region East China Sea (ECS), which is associated with global warming, has attracted considerable attention. Despite its relevance to air‐sea interaction phenomena, atmospheric consequences this SST increase remain largely unexplored. Using ERA5 reanalysis data set conjunction a moisture budget analysis, we found that during 1979–2022, warming ECS‐Kuroshio contributed intensification Asian Meiyu‐Baiu rainband...
Previous studies have demonstrated that the strong East Asian summer monsoon results mainly from westward intensification of North Pacific subtropical high (NPSH), or equivalently, enhancement western high. However, during early July in 2011 a southerly southeasterly moist flow gave rise to large amount precipitation over southwestern Japan and Korea anomalous dry conditions central China because extraordinary NPSH north. The formation occurred east is very rare, its physical mechanisms are...
The upper ocean, atmosphere and their interaction over the North Pacific exhibit pronounced decadal to interdecadal variations. A diagnostic equation for analyzing heat budget variability in winter sea surface temperature (SST) is derived that can properly account subsurface geostrophic advection, strong seasonal cycle depth of ocean mixed layer. modelassimilated dataset, partially validated period TOPEX/Poseidon mission, used evaluate relative importance advection forcing due wind-induced...
Abstract Using observational and reanalysis data sets, we investigated interannual variability in the Kuroshio East China Sea (ECS‐Kuroshio). We exhibited that surface velocity position of ECS‐Kuroshio were synchronized on a quasi‐3‐year timescale during 2005–2016. further demonstrated that: (a) 2005–2016, wind stress curl related to El Niño–Southern Oscillation (ENSO) played leading role by exciting baroclinic Rossby waves along subtropical countercurrent (STCC) zone east Taiwan; (b)...
Abstract Early summer climate in the western North Pacific is largely represented by baiu phenomenon. The meridional fluctuations of front on interannual time scales and associated large-scale circulations are examined using empirical orthogonal function (EOF) analysis composite or correlation analyses based EOF coefficients. first mode indicates a 5- 6-yr low-frequency fluctuation (LF mode) appearing south 35°N. development concurrent with horseshoe sea surface temperature anomalies (SSTAs)...
From 1950 to 1988, 10 ENSO (El Niño-Southern Oscillation) events have occurred. These are defined by using the Southern Oscillation index (SOI) and sea surface temperature (SST) anomaly in central equatorial Pacific. The classified based on positive length of SST time series: about a year with one northern winter, or two more years winters. shorter (BO-ENSO) terminates following occurrence, longer (LF-ENSO) after occurrence. occurrence termination both types strong phase preference seasonal...
The global patterns associated with decadal‐scale variability (DSV) are examined by a lag correlation technique based on local anomaly indices, using the fields of measured sea surface temperature (SST) and 850 hPa geopotential height for last 50 years. three dominant identified, is examined; first spreads over entire Pacific, which concurrent modulation El Niño/Southern Oscillation (DES variability), second confined to midlatitude North Pacific (LNP third extends Atlantic decadal (NAO) (DNA...
Abstract Proposed in 1954, Alisov’s climate classification (CC) focuses on climatic changes observed January–July large-scale air mass zones and their fronts. Herein, data clustering by machine learning was applied to global reanalysis quantitatively objectively determine zones, which were then used classify the climate. The differences between two half-year seasons subdivided into continental or maritime regions according east–west differences. This study renews CC for first time almost 70...
Abstract The Baiu frontal activity (BFA) clearly shows spatiotemporal differences in its interannual variability. This work examines the physical mechanisms behind these differences. On time scales, front can be divided into three subregions: (1) western (WB), (2) central (CB), and (3) eastern (EB). Time series analysis revealed that dominant periods subregions are long eastward of approximately 2 years WB, 4 CB, 6 EB. biennial oscillation Asian monsoon controls variation WB through specific...
This work examines two physical mechanisms that control the interannual variability of Baiu precipitation from late May to mid-July, using objective analysis data atmospheric parameters including 1979 2010 and sea surface temperature (SST) 1982 2010. In June, this period, mean circulation produces is altered. early season (May 26-June 24) after a warm El Niño/Southern Oscillation (ENSO) event, an anomalous anticyclone appears in western North Pacific (WNP) through Pacific-East Asian...
In the Kuroshio region (KR), early summer surface heat flux (SHF) exhibits a rapid increase around 1990 as climate shift, which is rooted in oceanic interdecadal variability North Pacific. The sea temperature (SST) KR, where SST largely controlled by subsurface ocean circulations, positively correlated with local upward SHF. positive SHF anomalies 1990s reinforced Baiu frontal activity an atmospheric large‐scale meridional dipole western As such, has impact on circulation through coherent...
Abstract The Baiu front, a quasi‐stationary front that appears in early boreal summer near the northwestern rim of subtropical Pacific high, shows interannual variability characterised by polarity changes precipitation anomalies during subseasonal northward excursion western North (WNP). These are forced motion over fixed surface divergence/convergence WNP, which regulated atmospheric bridge or Pacific–East Asian (PEA) teleconnection. PEA teleconnection is caused tropical sea temperature...
Observations of tropical convection and cloud clusters with two X-band Doppler radars were carried out on Manus Island, Papua New Guinea for a half months from 12 November 1992 during the Intensive Observation Period (IOP) TOGA-COARE. Several different types clouds observed by period, such as squall lines, convective stratiform associated clusters, isolated over island in day time, etc. Outlines observations Island brief reviews results these are described. Preliminary summaries analyses...
Abstract In the North Pacific, wintertime sea surface temperature anomaly (SSTA), which is represented by March (SSTAMar), when upper-ocean mixed layer depth (hMar) reaches its maximum, formed anomalous forcing from fall to winter (S′). As a parameter of volume, hMar has potential modify impact S′ on SSTAMar. Introducing an heat budget equation, present study identifies physical relationship among spatial distributions hMar, S′, and The long-term mean adjusts distribution Without adjustment,...
We report on green polymer light emitting diodes with improved efficiency and lifetime using a cross-linked hole transporting layer in this study. The poly[(9,9-dioctylfluorene)-alt-(triphenylamine)], which was used as material, by UV irradiation. of copolymer, poly[(9,9-dioctylfluorene)-co-(benzodiathiazole)], spin coated from its solution the top to prepare multilayer device. By introducing layer, maximum luminance, efficiency, external quantum and, especially, device were greatly...
Abstract Gradual cooling in the evening forms a wintertime nocturnal urban heat island. This work, with mesoscale model involving canopy physics, is an examination of how four thermal and geometric controls—anthropogenic QF, capacity C, conductivity k, sky-view factor ψs—modify rate surface air temperature changes ΔT/Δt. In particular, time dependence diagnosed through numerical experiments. The controls QF k are major agents evening, when ΔT/Δt linearly logarithmic. effects C ψs large...
Interannual variations of both the Baiu precipitation and tropical cyclone (TC) activity in western North Pacific (WNP) are controlled by large-scale atmospheric circulations associated with El Niño/Southern oscillation (ENSO) tropospheric biennial (TBO) Asian monsoon. This work examines covariability between TC WNP through ENSO TBO.In years when sea surface temperature anomalies (SSTAs) negative eastern respect to ENSO, number TCs increases near Philippines season, June July. On other hand,...
Decadal-scale modulation (DSM) appears in the atmospheric circulation change around onset (July 20) of western North Pacific summer monsoon (WNPSM). This work examined DSM associated with precipitation increase (OPI), using global reanalysis datasets from 1979 to 2010 (32 years). The years 1985-1993 had positive decadal anomalies, and increased development specific meridional similar Pacific-Japan pattern. In subsequent negative term 1994-2000, was distinguished by a smaller OPI,...