A5000577714- 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
- Geophysics and Gravity Measurements
- Atmospheric Ozone and Climate
- Geological and Geophysical Studies
- Atmospheric aerosols and clouds
- Atmospheric chemistry and aerosols
- Ionosphere and magnetosphere dynamics
- Arctic and Antarctic ice dynamics
- Aeolian processes and effects
- Cryospheric studies and observations
- Solar and Space Plasma Dynamics
- Marine and coastal ecosystems
- Soil Moisture and Remote Sensing
- GNSS positioning and interference
- Environmental Changes in China
- Maritime Transport Emissions and Efficiency
- Soil and Unsaturated Flow
- Climate change and permafrost
- Atmospheric and Environmental Gas Dynamics
- Urban Heat Island Mitigation
Japan Agency for Marine-Earth Science and Technology
2013-2024
United States Global Change Research Program
2011
Institute for Global Environmental Strategies
2004
Hokkaido Agricultural Research Center
1995-2002
Hokkaido University
1990-1991
Abstract Raindrop size distribution (RSD) characteristics in summer season rainfall of two observational sites (Taiwan (24°58′N, 121°10′E) and Palau (7°20′N, 134°28′E)) western Pacific are studied by using five years impact type disdrometer data. In addition to data, Tropical Rainfall Measuring Mission, Moderate Resolution Imaging Spectroradiometer, ERA‐Interim data sets used illustrate the dynamical microphysical associated with Taiwan Palau. Palau's raindrop spectra showed a significant...
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...
The long-term variability of Philippine summer monsoon onset from 1903 to 2013 was investigated. date is defined by daily rainfall data at eight stations in the northwestern Philippines. Summer monsoons tended start earlier May after mid-1990s. Other early periods were found during 1900s, 1920s, and 1930s, an interdecadal identified. Independent surface wind observed ships South China Sea (SCS) revealed prevailing westerly period. To identify atmospheric structures that trigger onset, we...
In order to reveal the characteristics of convective clouds over Tibetan Plateau, we carried out Doppler radar observations in suburbs Naqu city (4500 m ASL), which is located central part from 27 May 19 September 1998, during intensive observation period GEWEX Asian Monsoon Experiment Tibet. Diurnal variation echo are and echo-top height were remarkable throughout indicating formation development daytime their decaying at night. The area, extracted objectively grid data reflectivity, larger...
The present study investigates modulation by the Madden-Julian Oscillation (MJO) of storm track activity (STA) over North Pacific (NP) during boreal winter for El Nino and La Nina periods. STA defined vertically averaged synoptic eddy kinetic energy (EKE) greatly intensifies western (WNP) central eastern years, respectively, when MJO convection is located Indian Ocean (IO)-Maritime Continent. When moves into Pacific, in years suppressed (enhanced) at higher (lower) latitudes than years....
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...
Due to the severe threat of tropical cyclones human life, recent years have witnessed an increase in investigations on raindrop size distributions improve their quantitative precipitation estimation algorithms and modeling simulations. So far, using disdrometer measurements been conducted at coastal inland stations, but such studies are still missing for oceanic locations. To authors’ knowledge, current study examines—for first time—the fourteen observed (during 2003–2007) station, Aimeliik,...
The Hydrometeorological ARray for Isv-Monsoon AUtomonitoring (HARIMAU), a 5-year project under the Japan EOS Promotion Program (JEPP) contributing to Global Earth Observation System of Systems (GEOSS), has begun in 2005 set up radar-profiler network observing world's most active convective activities over Indonesian Maritime Continent (IMC). Rainfall and wind distributions are displayed nearly real time on internet. Both scientific understanding practical concepts intraseasonal variations...
The future changes in the Madden-Julian Oscillation (MJO) and its extratropical teleconnection East Asia during boreal winter are examined by analyzing 12 climate models with good simulation skills of MJO convective signal Coupled Model Intercomparison Project phase 3 (CMIP3). convection increases over western to central Indian Ocean (IO) under warming seven (MJO-plus models). However, it decreases other five (MJO-minus wintertime sea surface temperature (SST) exhibits more El Niño-like...
The authors investigate the interannual rainfall variability over eastern maritime continent using station data in Republic of Palau during 1923-2009 and Eastern Indonesia 1973-2008. Two possible mechanisms are proposed to explain associated with El Niño/Southern Oscillation surrounding region Banda Arafura seas.During Niño developing year, starts decrease, first close equator summer than off-equatorial autumn, such as mainland Palau. has a dry season boreal general, becomes significantly...
Abstract The multiscale structure of a super cloud cluster (SCC) over the equatorial Indian Ocean, observed in November and December 2006, was investigated using data from satellite microwave sensors surface-based radars. smaller-scale this SCC marked by complicated relationship between rainfall systems upper-tropospheric shields, which moved eastward westward, respectively, with cycle 2–4 days. In analyses, attention given to slow eastward-propagating (5–11 m s−1) precipitating related...
[1] Equatorial westerly wind bursts (WWBs) and their relationship with El Nino–Southern Oscillation (ENSO) in the 18 climate models presented World Climate Research Programme's Coupled Model Intercomparison Project phase 3 (CMIP3) are examined. Some depict a realistic eastward shift of collective occurrences WWBs over Pacific as warm pool expands eastward. These that frequent western preceding Nino peak, known to trigger or enhance Nino, tend reproduce background states ENSO more accurately....
[1] The cooperative Indian Ocean experiment on intraseasonal variability in the Year 2011 (CINDY2011) was conducted to capture atmospheric and oceanic characteristics of Madden-Julian Oscillation (MJO) central from late early 2012. During CINDY2011, research vessel (R/V) MIRAI stayed at 8°S, 80.5°E for two months during special observing period (SOP). Intraseasonal convection associated with MJO organized October November SOP. In middle November, both sea surface temperature (SST) mixed...
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 Cirrus cloud variability associated with n = 0 eastward inertio‐gravity equatorial waves and Kelvin (both the period of ~4 days) wave another periodicity (~16 were observed in tropical Indian Ocean (8.0°S, 80.5°E) November 2011 during Cooperative experiment on intraseasonal Year (CINDY2011)/Dynamics Madden‐Julian Oscillation (DYNAMO) field campaign using balloon‐borne cryogenic frostpoint hygrometers, Vaisala radiosondes, a shipborne high spectral resolution lidar system. During...
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...
During the GAME-Tibet Intensive Observation Period (IOP), precipitation radar (PR) of Tropical Rainfall Measuring Mission (TRMM) satellite detected a diurnal cycle rainfall in Tibet. Much was brought both by convection daytime and stratiform over wide rain area evening night. Two case studies were conducted to clarify structure nighttime. In Case 1 (7 8 July 1998), observed On 7 July, synoptic convergence developed southern part Plateau evening. Southwesterly wind dominated above 6 km ASL,...
The simulated Madden-Julian oscillation (MJO) in the climate of 20th Century (20C3M) experiment 23 models participating Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) is examined. having moisture-convergence-type convection schemes well simulate MJO signal precipitation. By analyzing data from these models, we confirm that active Indian Ocean to western Pacific, consistent with observations. However, analyses structure reveal convergence surface wind tends be...
Abstract In this study, the authors focused on seasonal variations of precipitation properties over western Pacific, particularly those associated with wind direction monsoon. An observational project Peleliu Island in Republic Palau was carried out, and data precipitation, equivalent cloud amount, precipitable water were collected from 28 June 2001 to 30 April 2002. First, monsoon season defined as a period 850-hPa zonal-wind sounding sustained winds exceeding 5 m s−1. The westerly regime...
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...
A simple model to estimate the daily mean soil temperature using routine meteorological data has been developed. The is based on a heat budget equation connected with Force-Restore Model, in which interdiurnal variation of at surface layer estimated. some advantages. First, it not necessary set up thermometric parameters and initial values deep layer. Second, sensitivities are low compared case estimating diurnal temperatures. Finally, boundary condition easy determine because annual...
We performed synergy observation of subvisual cirrus clouds (SVC) with 1064‐nm lidar, 95‐GHz cloud radar and radiosondes launched every 3 hours at 2°N, 138°E for one month from 9 November to December 2001. The estimated effective radius r eff SVC is 9–16 μm (5–9 in mode radius). This assumes that the shape particles spherical number concentration 10 5 m −3 . disappear when temperature anomalies exceed +1.5°C. fall velocity same as downward phase propagation Kelvin wave, terminal hexagonal...
This paper describes the structure and evolution of northward propagating mesoscale convective systems (MCSs) observed over tropical western Pacific on 15 June 2005. A wedge‐shaped cloud area, consisting three groups MCSs, was generated near equator to north New Guinea at around 0000 LST June, one MCSs propagated toward Palau (7°–8°N). Dropsonde analysis revealed that developed northern edge a cold air mass had horizontal scale more than 400 km. Global objective data from Japan...