九州大学 · 環境科学
本研究室は、気象・大気現象の高精度な観測と解析を目的とし、レーダー・ライダーを用いた雲・降水の微物理的・動力学的特性の同時推定に注力しています。特に、95GHzレーダーとライダーの連携による氷雲の微粒子特性や垂直風上昇運動の同時推定アルゴリズムの開発が特徴です。また、偏光比やリモートセンシング信号の多重散乱効果を精密に再現する物理モデルの構築にも貢献しています。
Figures are computed from collected data and may differ slightly.
Although the prior literature has examined the relationship between work schedule characteristics and worker mental health, establishing the causal effect of work schedule characteristics is challenging because of endogeneity issues. This paper investigates how various work schedule characteristics affect workers' mental health using employee surveys and actual working hours recorded over seventeen months in a Japanese manufacturing company. Our sample includes 1334 white-collar workers and 786
[1] This work improved on the lidar and radar retrieval algorithm developed by Okamoto et al. to extend the applicability of the microphysical retrieval scheme from the cloud region with lidar-radar overlap to lidar- or radar-only cloud regions with an available radar-lidar overlap area in the vertical profile by use of the Levenberg-Marqardt method. The algorithm was formulated to efficiently reflect the information from the lidar-radar overlap region to the microphysical retrieval at the radar
Effect of density, shape, and orientation on radar reflectivity factor ( Z e ) and linear depolarization ratio ( LDR ) at 95 GHz are investigated by using the discrete dipole approximation (DDA) for ice cloud studies. We consider hexagonal plate, hollow hexagonal column, and hollow bullet rosette in horizontal (2‐D) or three‐dimensional (3‐D) random orientation. We first validate a widely used method to take into account the density and shape effects by the combinational use of Mie theory with t
The backscattering optical properties of an ensemble of randomly oriented dust particles at a wavelength of 355 nm were comprehensively studied by examining the invariant imbedding T-matrix results of the super-spheroid dust model. In particular, we focused on the lidar ratio ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:mrow><mml:mi>S</mml:mi></mml:mrow> </mml:mrow> </mml:math> ) and depolarization ratio ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <m
We introduce a combined 95‐GHz radar multi‐parameter (radar reflectivity Z e , Doppler velocity V D , and/or linear depolarization ratio LDR ) and lidar backscatter coefficient β bk algorithm for the simultaneous retrieval of ice cloud microphysics and in‐cloud vertical air motion V air within a single radar volume. Unlike earlier methods, our new approach is not limited to a specific temporal or spatial scale of V air , which makes it applicable to the interaction between cloud dynamics and ice
A physical model was extended with a polarization function to create a vectorized physical model (VPM) to analyze the vertical profile of the observed depolarization ratio due to multiple scattering from water clouds by space-borne lidar. The depolarization ratios due to single scattering, on-beam multiple scattering, and pulse stretching mechanisms are treated separately in the VPM. The VPM also includes a high-order scattering matrix and accommodates mechanisms that modify the polarization sta
A practical model for determining the time-dependent lidar attenuated backscattering coefficient β was developed for application to global lidar data. An analytical expression for the high-order phase function was introduced to reduce computational cost for simulating the angular distribution of the multiple scattering irradiance. The decay rate of the multiple scattering backscattered irradiance was expressed by incorporating the dependence on the scattering angle and the scattering order based
Thyroid damage was more severe, recovery slower and the rate of relapse higher in the immunological than in the chemical type of reversible hypothyroidism.
Abstract A more accurate representation of ice‐phase processes in numerical models necessitates an enhanced understanding of ice‐particle microphysics and their respective formation conditions. Prior in situ measurements have noted distinctive ice‐particle shape characteristics associated with different cloud systems and geographical locations. The recent advancement in ice‐particle backscattering theories enables a more comprehensive exploration of the geographical distribution and seasonal dep
This study analyzed 95‐GHz radar/lidar data collected from the R/V Mirai over the tropical western Pacific to characterize the vertical distribution of ice cloud effective radius r eff , ice water content IWC, and in‐cloud vertical velocity of the region in conjunction with weather regimes classified by International Satellite Cloud Climatology Project (ISCCP) cluster analysis. Ice clouds observed from the Mirai were roughly consistent with the ISCCP weather regimes; more convectively active reg
Studies have shown that half of Japanese midwives experience depression ( Akizuki and Fujimura, 2006 ), but the stress experienced by them is not well understood. This study examines job stress among midwives in hospitals and clinics in the Tokyo area. The Brief Job Stress Questionnaire (BJSQ) was distributed to 1397 midwives at 90 facilities. Responses were received from 606, and the valid responses of 556 respondents were analysed. The results showed that 442 midwives (79.5%) experienced a qua
Abstract. This study introduces the primary products and features of active-sensor-based Level 2 cloud microphysics products of the Japanese Aerospace Exploration Agency (JAXA; i.e., the cloud radar standalone cloud product (CPR_CLP), the radar–lidar synergy cloud product (AC_CLP), and the radar–lidar–imager cloud product (ACM_CLP)). Combined with the 94 GHz Doppler cloud profiling radar (CPR), 355 nm high-spectral-resolution lidar (Atmospheric Lidar, ATLID) and Multi-Spectral Imager (MSI), thes
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