A5091795301- Precipitation Measurement and Analysis
- Meteorological Phenomena and Simulations
- Soil Moisture and Remote Sensing
- Climate variability and models
- Geophysics and Gravity Measurements
- Atmospheric aerosols and clouds
- Radio Wave Propagation Studies
- Cryospheric studies and observations
- Tropical and Extratropical Cyclones Research
- Ocean Waves and Remote Sensing
- Atmospheric and Environmental Gas Dynamics
- Icing and De-icing Technologies
- Oil Spill Detection and Mitigation
- Ionosphere and magnetosphere dynamics
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Environmental and Agricultural Sciences
- Atmospheric Ozone and Climate
- Geophysical Methods and Applications
- GNSS positioning and interference
- Image Processing and 3D Reconstruction
- Computational Physics and Python Applications
- Advanced Optical Sensing Technologies
- Spectroscopy and Laser Applications
- Power Line Communications and Noise
- Environmental Monitoring and Data Management
Dokkyo University
2006-2023
Institute of Electrical and Electronics Engineers
2021
Alpha Omega Electromagnetics (United States)
2021
Nagoya University
2005-2016
Japan Aerospace Exploration Agency
2009-2010
Kanazawa University
2009
Norsk Hydro (Slovakia)
2009
Ministry of Internal Affairs and Communications
1990-2005
Japan Science and Technology Agency
2005
Chiba University
2005
Precipitation affects many aspects of our everyday life. It is the primary source freshwater and has significant socioeconomic impacts resulting from natural hazards such as hurricanes, floods, droughts, landslides. Fundamentally, precipitation a critical component global water energy cycle that governs weather, climate, ecological systems. Accurate timely knowledge when, where, how much it rains or snows essential for understanding Earth system functions improving prediction resources,...
The Tropical Rainfall Measuring Mission (TRMM) satellite was launched on 27 November 1997, and data from all the instruments first became available approximately 30 days after launch. Since then, much progress has been made in calibration of sensors, improvement rainfall algorithms, applications these results to areas such as assimilation model initialization. TRMM Microwave Imager (TMI) corrected verified account for a small source radiation leaking into TMI receiver. precipitation radar...
The rainfall‐elevation relationship in the central Himalayan region (CHR) for pre‐monsoon and monsoon seasons is analyzed utilizing 11‐year (1998–2008) high‐spatial‐resolution TRMM PR 2A25 near‐surface rainfall data. results indicate a strong between elevation during both seasons. investigation reveals relatively large amount of over higher elevations season. Interestingly, two significant peaks appear southern slope Himalayas summer first primary peak appears along Sub‐Himalayas (∼500–700 m...
Observations from the precipitation radar aboard Tropical Rainfall Measuring Mission satellite provide first opportunity to map vertical structure properties of rain over entire Tropics and subtropics. Storm height histograms reveal a distinct bimodal distribution oceans with lowest mode near 2 km upper at 5 km. The low is dominant feature regions previously associated precipitating marine stratocumulus/stratus trade wind cumulus. In those lognormal fits observed storm distributions quite...
The Global Precipitation Climatology Center global-precipitation-analyses rain gauge data have been used to validate the Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) over major climatic regions in Africa. threshold-matched index and TRMM-and-other-sources "best-estimate" (3B43) also compared with TRMM PR rainfall product. In 36-month climatological assessment of satellite products at a grid spacing 1.0°, continental Africa has categorized into five distinct regions:...
Rain rate estimation properties of multiparameter radar measurements combining reflectivity and microwave attenuations are studied through simulations using a two-year disdrometer dataset. In the first simulation, "complete" measurements, where error-free assumed for each resolution cell, investigated. The result indicates that dual-parameter (DP) provide an excellent accuracy in rain estimation. Most DP possible from space "semi-" (SDP) defined as which spatial attenuation measurement is...
Rainfall is a fundamental process within the Earth's hydrological cycle because it represents principal forcing term in surface water budgets, while its energetics corollary, latent heating, source of atmospheric diabatic heating well into middle latitudes. Latent heat production itself consequence phase changes between vapor, liquid, and frozen states water. The properties vertical distribution release modulate large-scale meridional zonal circulations Tropics, as modify energetic...
The spatial and diurnal variation of rainfall over Asia was investigated using the spaceborne radar data for four seasons during 1998–2003. regional prevailing precipitation systems most closely associated with maximum hourly shown by examining fine distribution amount scale‐based systems. Small (<10 2 km ) occurred frequently around early afternoon land. south facing slopes Himalayas, especially Mount Everest upper portion Brahmaputra valley, is obvious region daytime genesis convective...
Abstract The climatological features of the diurnal cycle and its spatial temporal variability are investigated around Himalayas using hourly, 0.05° × grid, near-surface rainfall data from Precipitation Radar (PR) aboard Tropical Rainfall Measuring Mission (TRMM) satellite during June–July–August (JJA) 1998–2002. Though sampling errors inherent to TRMM PR measurements could influence results, PR-observed precipitation show agreement with previous studies in this region. analysis...
Abstract Characteristics of raindrop size distribution (DSD) are studied during the southwest (SW) and northeast (NE) monsoon seasons using 4 1/2 years DSD measurements made at Gadanki (13.5°N, 79.2°E) by an impact‐type disdrometer. The observed is found to be distinctly different in NE from that SW monsoon. stratified (based on rain rate) shows more small drops fewer bigger than monsoon, particularly low rate regime. This feature not anomalous one, rather consistently all years. diurnal...
Abstract Yanai and coauthors utilized the meteorological data collected from a sounding network to present pioneering work in 1973 on thermodynamic budgets, which are referred as apparent heat source (Q1) moisture sink (Q2). Latent heating (LH) is one of most dominant terms Q1. Yanai’s paper motivated development satellite-based LH algorithms provided theoretical background for imposing large-scale advective forcing into cloud-resolving models (CRMs). These CRM-simulated Q1 have been used...
Disdrometer data measured during the passage of tropical continental squall lines in Darwin, Australia, are analyzed to study characteristics raindrop size distribution (DSD). Fifteen were selected for DSD analysis. An observed line was partitioned into three regions based on radar reflectivity pattern, namely, convective line, stratiform, and trough. A further center, leading edge, trailing edge using a threshold rain rate 20 mm h−1. Statistics modified gamma parameters obtained by least...
Long‐term measurements of raindrop size distribution (DSD) made with the Joss‐Waldvogel disdrometers at two sites (Gadanki, an inland station, and Cuddalore, a coastal station) in southeast India are utilized to study seasonal spatial variations DSD. The stratified DSD data (based on rain rate R ) show significant variation both sites. Smaller‐drop concentration is higher northeast monsoon (NEM) than southwest (SWM) for same . Paucity smaller drops SWM increases mass weighted mean diameter (...
Abstract Tropical Rainfall Measuring Mission (TRMM) data during June–August 1998–2003 are used to investigate diurnal variations of rain and cloud systems over the tropics midlatitudes. The peak time coldest minimum brightness temperature derived from Visible Infrared Scanner (VIRS) maximum rate Precipitation Radar (PR) TRMM Microwave Imager (TMI) compared. Time distributions generally consistent with previous studies. However, it is found that systematic shifts in relative each sensor...
The diurnal cycle of rainfall over the central Tibetan Plateau was investigated by examining data acquired Tropical Rainfall Measuring Mission Precipitation Radar during summer monsoon season (June–August) from 1998–2007. High‐spatial‐resolution (∼5 km × 5 km) were used to identify role complex topographic features plateau. Diurnal variations in rain rate, frequency rain, conditional and storm‐height analyzed on a monthly basis determine characteristics precipitation. results are interpreted...
Abstract Rain radar measures instantaneous spatial-average rainfall, while conventional rain gauges directly measure point rainfall with low temporal resolution. Thus differences in the resolution of sensors create difficulties for validation, especially spaceborne radar. Accordingly, measurement by microwave link has been proposed several decades, as it estimates path-average rainfall. is expected that gauge will overcome, at least partly, problems toward which a 50-GHz band [the...
Rain gauge data for the period of 1998–2004 from Syangboche Automated Weather Station (S-AWS) site in Nepal Himalayas were compared with multi-satellite precipitation products 2003–2005, employing several retrieval algorithms: Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis (TMPA), Climate Prediction Center (CPC) morphing algorithm (CMORPH), Estimation Remote Sensing Information using an artificial neural network (PERSIANN), and Global Satellite Mapping...
Surface rain rates over the ocean derived from Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) and precipitation radar (PR) are compared systematic differences between TMI-derived PR-derived shown. Three plausible reasons for these were found. One is a problem in freezing-level assumption TMI algorithm midlatitude regions winter, which results underestimation of rates. Second inadequate Z–R or k–R relationships convective stratiform types PR algorithm. Third incorrect...
An aircraft experiment has been conducted with a dual-frequency (X/Ka-bands) radar to test various rainfall retrieval methods from space. The authors method derive raindrop size distribution (DSD) parameters the combination of reflectivity profile and path-integrated attenuation derived surface return, which may be available most spaceborne radars. results indicate feasibility dual-parameter measurement space in achieving better accuracy quantitative remote measurements.< <ETX...
The precipitation variability and circulation characteristics around the Himalayas are examined using Tropical Rainfall Measuring Mission (TRMM) data, Global Energy Water Cycle Experiment (GEWEX) Asian Monsoon (GAME) reanalysis, National Centers for Environmental Prediction–National Center Atmospheric Research (NCEP‐NCAR) some of Indian radiosonde data sets. observation by radar on board TRMM satellite reveals an afternoon maximum during premonsoon season midnight–early morning summer...
AB STRACTCon stel la tion Ob serv ing Sys tem for Me te o rol ogy Ion sphere and Cli mate (COS MIC), con sist of six Low Earth Or bit (LEO) Global Po si (GPS) re ceiv ers, on board the Formosat Sat el lite 3 (FORMOSAT-3) is pro vid dense ob ser va tions den sity, refractivity, per a ture wa ter por files neu tral at mo since mid dle July 2006.Spe cial ra dio sonde (Väisälä) cam paign was ducted Gadanki (13.48°N, 79.18°E), trop i cal site in In dia, dur 2006 to March 2007 val date these me ro...
Abstract The lower atmospheric wind profiler (LAWP) measurements made at Gadanki, India, have been used to develop an objective algorithm classify the tropical precipitating systems. A detailed investigation on existing classification scheme reveals major shortcomings in scheme. In present study, it is shown with examples that Doppler velocity gradient (DVG) criterion a necessary but certainly not sufficient condition identify radar bright band. Such gradients can exist other types of rain...
Seasonal and spatial variation of the vertical gradient rainfall rate was investigated using global precipitation data observed by Precipitation Radar (PR) on Tropical Rainfall Measuring Mission (TRMM) satellite. The rendered features downward decreasing (DD) or increasing (DI) in lower part profile. DD profiles dominated tropical interior landmasses such as Africa Brazilian Plateau summer. DI were over land winter ocean except for regions with very little rainfall. In addition, appeared...