A5064446174- Climate variability and models
- Meteorological Phenomena and Simulations
- Tropical and Extratropical Cyclones Research
- Oceanographic and Atmospheric Processes
- Ocean Waves and Remote Sensing
- Precipitation Measurement and Analysis
- Atmospheric aerosols and clouds
- Geophysics and Gravity Measurements
- Solar and Space Plasma Dynamics
- Satellite Communication Systems
- Ionosphere and magnetosphere dynamics
- Aeolian processes and effects
- Seismic Waves and Analysis
- Geological and Geophysical Studies
- Atmospheric and Environmental Gas Dynamics
- Arctic and Antarctic ice dynamics
- Atmospheric chemistry and aerosols
- High-pressure geophysics and materials
- Atmospheric Ozone and Climate
- Seismic Imaging and Inversion Techniques
- Scientific Research and Discoveries
- Plasma and Flow Control in Aerodynamics
- Environmental Changes in China
- Antenna Design and Optimization
- Management and Optimization Techniques
University of Toyama
2013-2024
Japan Agency for Marine-Earth Science and Technology
2009-2020
Lamont-Doherty Earth Observatory
2020
Goddard Institute for Space Studies
2020
Universities Space Research Association
2020
Columbia University
2020
University of Michigan
2020
NOAA Geophysical Fluid Dynamics Laboratory
2018
University Corporation for Atmospheric Research
2018
University of Miami
2018
Abstract This study analyzes data obtained by intensive observation during a pilot field campaign of the Years Maritime Continent Project (Pre-YMC) to investigate diurnal cycle precipitation in western coastal area Sumatra Island. The period (November–December 2015) is found have number similarities with statistical behavior as revealed previous studies, such afternoon over land, nighttime offshore migration zone, and dependency on Madden–Julian oscillation (MJO) phase. Composite analyses...
The Mirai Indian Ocean cruise for the Study of Madden-Julian oscillation (MJO)-convection Onset (MISMO) was a field experiment that took place in central equatorial during October–December 2006, using research vessel Mirai, moored buoy array, and landbased sites at Maldive Islands. aim MISMO to capture atmospheric oceanic features when convection MJO initiated. This article describes details as well some selected early results. Intensive observations Doppler radar, radiosonde, surface...
Abstract Precipitation-related differences in different types of convectively coupled equatorial waves are examined here and a companion paper. Here the authors show spectra cross-spectra among tropical-belt time sections satellite-derived surface rain, infrared brightness temperature Tb, precipitable water (PW), Japan Meteorological Agency reanalysis divergence PW. Cross-spectra between rain at 1000- 200-hPa levels significant coherence peaks oriented along dispersion curves Kelvin, n = 1...
Abstract A new diagnostic framework is developed and applied to ERA-Interim quantitatively assess vertical velocity (omega) profiles in the wavenumber–frequency domain. Two quantities are defined with first two EOF–PC pairs of omega tropical ocean: a top-heaviness ratio tilt ratio. The ratios defined, respectively, as cospectrum quadrature spectrum PC1 PC2 divided by power PC1. They represent how top-heavy an profile at convective maximum, much contain spatiotemporal evolution wave. reveals...
Abstract This paper describes an analysis of multiyear satellite datasets to characterize the modulations convective versus stratiform rain, rain system size, and column water vapor by convectively coupled equatorial waves. Composites are built around space–time filtered equatorial-belt data from Tropical Rainfall Measuring Mission (TRMM) 3B42 rainfall product, while TRMM Precipitation Radar (PR) passive microwave composited variables. The results consistent with more reanalysis-dependent...
Abstract Tropospheric moisture is a key factor controlling the global climate and its variability. For instance, moistening of lower troposphere necessary to trigger convective phase Madden–Julian oscillation (MJO). However, relative importance processes this has yet be quantified. Among these processes, by shallow convection still debated. The authors use high-frequency observations humidity from Research Vessel (R/V) Mirai that was located in Indian Ocean ITCZ during Cooperative Experiment...
Abstract This study investigates the climatological relationship between diurnal rainfall migration and ambient wind over southern Sumatra by using observation reanalysis of 15 years data from Tropical Rainfall Measuring Mission satellite precipitation radar. When winds in lower troposphere (1000–500 hPa) are westerly, convective systems migrate eastward, while dominated stratiform propagate to west association with mid‐upper level easterly winds. throughout troposphere, both only west....
Abstract The budget of column-integrated moist static energy (MSE) is examined in wavenumber–frequency transforms longitude–time sections over the tropical belt. Cross-spectra with satellite-derived precipitation (TRMM-3B42) are used to emphasize precipitation-coherent signals reanalysis [ERA-Interim (ERAI)] estimates each term equation. Results reveal different balances convectively coupled equatorial waves (CCEWs) as well Madden–Julian oscillation (MJO) and depression (TD)-type...
The Baiu (Mei-yu) front over East Asia in the global warming climate as well that present one, is studied using outputs of a non-hydrostatic regional model with horizontal grid size 5 km (NHM). NHM was run June and July for ten years, applying spectral boundary coupling method to reduce phase differences large-scale disturbances 20 km. In climate, likely stay southern Japan Islands around latitudes 30 N-32 N will not move northward. Therefore, activity maintains longer than precipitation...
Abstract A field observational campaign [i.e., the Mirai Indian Ocean cruise for Study of MJO-convection Onset (MISMO)] was conducted over central equatorial in October–December 2006. During MISMO, large-scale organized convection associated with a weak Madden–Julian oscillation (MJO) broke out, and some other notable variations were observed. Water vapor precipitation data show prominent 3–4-day-period cycle meridional wind υ variations. Filtered anomalies at midlevels reanalysis Japan...
We used a three‐year dataset from an impact disdrometer to study the diurnal interannual variation of raindrop size distribution (DSD) over Palau in Western Pacific warm pool. The DSD variability was primarily seasonal, with secondary contribution due El Niño Southern Oscillation (ENSO) cycle. did not find evidence In seasonal cycle, mean drop diameters tended increase during westerly monsoon period. Within this period, generally increased year and decreased La Niña year. However, within...
Abstract This paper describes the propagation of influence radiosonde observations made during MISMO (Mirai Indian Ocean cruise for Study Madden–Julian oscillation‐convection Onset), which was conducted over in boreal autumn 2006. The impact these assessed using an experimental reanalysis called ‘ALERA’ that produced by local ensemble transform Kalman filter with atmospheric global circulation model Earth Simulator. difference analysis mean between cycles and without used to quantify on...
To study crustal rock seismic anisotropy and its effect on wave propagation, we measure the velocity of two amphibolites, one biotite gneiss schist from Hidaka metamorphic belt in central Hokkaido, Japan, under confining pressures up to 150 MPa. The microstructures show foliation lineation characterized by lattice preferred orientation (LPO) hornblende or biotite. P‐ S‐wave velocities are measured along direction perpendicular plane directions plane: parallel lineation. We assume...
Abstract The spectral boundary coupling (SBC) method, which is an approach used to couple a limited-area model with large-scale model, was introduced into nonhydrostatic model. To investigate whether the SBC method works well in long-term integration of high-resolution two numerical experiments were conducted having horizontal grid interval 5 km. In one experiment, employed, while it not other experiment. time both over 40-day period. nested objectively analyzed fields, instead forecasts...
Abstract In this study, cloud profiling radar and lidar were used to determine the frequency distribution of base heights cloudy layers with little (or no) falling condensate particles. The data obtained from stationary observations conducted Research Vessel Mirai over tropical western Pacific (around 1.85°N, 138°E) 9 November December 2001. observed had predominantly in range 4.5–6.5 km. Almost all a km thickness thinner than 500 m, peak measured is considered represent common occurrence...
Changes in the Baiu frontal activity future climate are examined, making use of super-high-resolution global and cloud-resolving regional models (20-km-mesh AGCM 5-km-mesh NHM). In present study, focus is on lengthened duration Baiu, characteristics precipitation during season climate.First, 10-year global-scale simulations present, climates conducted by 20-km-mesh AGCM. The simulation accurately reproduces northward shift front with time, end around Japan. climate, Pacific anti-cyclone...
Regional climate experiments focusing on the Baiu frontal precipitation were performed Earth Simulator using a non-hydrostatic cloud-system-resolving atmospheric model (NHM) with horizontal resolution of 5 km (5km-NHM) and 1 (1km-NHM). The outputs an general circulation (AGCM) about 20 used as boundary 5km-NHM. time-slice method in both present future climates was applied for AGCM NHM. In experiments, it evaluated that distribution frequency spectrum (PFS; intensities) 5km-NHM well...
Under the Kyosei-4 Project, unprecedented high resolution global and regional climate models were developed on Earth Simulator to investigate effect of warming tropical cyclones, baiu frontal rainfall systems, heavy events that could not be resolved using conventional models. For model, a nonhydrostatic model (NHM) with horizontal 5 km was used in simulation during season Japan. Simulations June July executed for 10 years present future climates. It found that, due warming, mean is projected...
This study examines seasonal and regional variations in the amplitudes of convectively coupled equatorial waves (CCEWs), including Madden-Julian oscillation (MJO) tropical depression (TD) disturbances. The climatological n = 1 Rossby (ERn1) wave are similar to those MJO over Indian Ocean central Pacific. antisymmetric components CCEWs (mixed gravity, 0 eastward inertial 2 westward gravity waves; MRG, EIGn0, WIGn2 waves, respectively) show cycles Pacific with peaks during boreal summer...
Abstract Long-term changes in the monthly precipitation along coastal areas of Sea Japan are examined using operational observation data from Meteorological Agency. The December significantly increased mid-1980s to 2015, even though no remarkable were found January, February, or November. Significant positive trends extend widely over Japan, and amounts increase approximately 50% climatological at most observational stations. interannual variations other variables, including accumulated...
The present paper investigates the relationship between skin sea surface temperature (SSTskin) and precipitable water (PW) observed over tropical Indian Ocean. PW is derived from a shipborne Global Positioning System (GPS). Composite diurnal variations indicate that increase of radar echo coverage (rainfall) in daytime correspond to large SSTskin rise during undisturbed period (The statistically significant at 90% level). fluxes calculated using bulk flux algorithm are too small account for...
Abstract This paper describes an analysis of multiyear satellite datasets that subdivide two halves (faster and slower) the space–time spectral signal peaks corresponding to convectively coupled equatorial waves such as Kelvin inertia–gravity [n = 0 eastward wave (EIGn0 wave), n 1 2 westward (WIGn1 WIGn2 waves, respectively)]. The faster (slower) component is defined which has a peak in regions with deeper (shallower) equivalent depths. data obtained from Tropical Rainfall Measuring Mission...
The effect of the assimilation dropsonde data over tropical western Pacific was investigated in an objective analysis. In June 2005, 30 dropsondes were released on four separate flight days. impact assessed using analysis dataset “ALERA.” zonal wind field ALERA revealed large errors corresponding to active convection. These reduced by 1-3 m s-1 due dropsondes. signal propagated northward and appeared significantly around Japan. phase group speeds at 700 hPa approximately 3 12 s-1,...
Analyzing outputs of seven climate models participating in the fifth phase Climate Model Intercomparison Project, this study performs multi-model projection tropical cyclone (TC) genesis frequency over Western North Pacific basin, with an emphasis on spatial contrast. By evaluating reproducibility spatio-temporal distribution frequency, we select five to perform projection. All and ensemble project eastward shift Main Development Region (MDR) TCs located around Philippines. This is probably...