Measurement of snow surface emissivity     

Junsei Kondo  Hiromi Yamazawa 《Boundary-Layer Meteorology》1986,34(4):415-416

Measurements of the snow surface emissivity for infrared radiation have been made with an infrared radiation thermometer. The mean value of the emissivity is estimated at = 0.970 ± 0.008.  相似文献   

Bulk transfer coefficient over a snow surface   总被引：1，自引：0，他引：1  

Junsei Kondo  Hiromi Yamazawa 《Boundary-Layer Meteorology》1986,34(1-2):123-135

The drag coefficient C _D and the bulk transfer coefficient for sensible heat C _H over a flat snow surface were determined experimentally. Theoretical considerations reveal that C _D depends on the friction velocity u _* as well as on the geometrical roughness h of the snow surface. It is found that C _D increases with increasing u _* and/or h. The dependency of C _H on u _* and h is so small that it is possible to consider C _H as a constant for practical purposes: C _{H, 1} = 2.0 × 10^–3 for a reference height of 1 m. The bulk transfer coefficient for water vapor is estimated at C _{E, 1} = 2.1 × 10^–3 for a reference height of 1 m.  相似文献   

Observation and modeling of thermally induced upslope flow     

Tsuneo Kuwagata  Junsei Kondo 《Boundary-Layer Meteorology》1989,49(3):265-293

Thermally induced upslope flows were observed on several slopes and in valleys, and a simple one-layer model of upslope flow was developed. In this model, the thickness and speed of upslope flow are expressed in terms of sensible heat flux from the slope surface, drag coefficient of the slope surface, slope steepness and stability of the ambient atmosphere. Model results compare favorably with the observations.The development process in the upslope direction of a steady upslope flow was investigated with this model. A steadily developing state in the upslope direction is expressed by the dimensionless equations together with a unique parameter associated with momentum advection. The vertical distance of the slope required for well-developed upslope flow has a minimum value for a moderate slope steepness, but increases monotonously with decreasing ambient stability. The effect of unsteadiness on upslope flow was also investigated. The transient time required to reach a steady state becomes shorter with increasing ambient stability and slope steepness.  相似文献   

On the importance of accurately ray-traced troposphere corrections for Interferometric SAR data     

Thomas Hobiger  Youhei Kinoshita  Shingo Shimizu  Ryuichi Ichikawa  Masato Furuya  Tetsuro Kondo  Yasuhiro Koyama 《Journal of Geodesy》2010,84(9):537-546

Numerical weather models offer the possibility to compute corrections for a variety of space geodetic applications, including remote sensing techniques like interferometric SAR. Due to the computational complexity, exact ray-tracing is avoided in many cases and mapping approaches are applied to transform vertically integrated delay corrections into slant direction. Such an approach works well as long as lateral atmospheric gradients are small enough to be neglected. But since such an approximation holds only for very rare cases it is investigated how horizontal gradients of different atmospheric constituents can evoke errors caused by the mapping strategy. Moreover, it is discussed how sudden changes of wet refractivity can easily lead to millimeter order biases when simplified methods are applied instead of ray-tracing. By an example, based on real InSAR data, the differences of the various troposphere correction schemes are evaluated and it is shown how the interpretation of the geophysical signals can be affected. In addition, it is studied to which extend troposphere noise can be reduced by applying the exact ray-tracing solution.  相似文献   

Asymmetric tropospheric delays from numerical weather models for UT1 determination from VLBI Intensive sessions on the baseline Wettzell–Tsukuba     

Johannes Böhm  T. Hobiger  R. Ichikawa  T. Kondo  Y. Koyama  A. Pany  H. Schuh  K. Teke 《Journal of Geodesy》2010,84(5):319-325

One-baseline 1-h Very Long Baseline Interferometry (VLBI) Intensive sessions are carried out every day to determine Universal Time (UT1). Azimuthal asymmetry of tropospheric delays around the stations is usually ignored and not estimated because of the small number of observations. In this study we use external information about the asymmetry for the Intensive sessions between Tsukuba (Japan) and Wettzell (Germany), which are carried out on Saturdays and Sundays (1) from direct ray-tracing for each observation at Tsukuba and (2) in the form of linear horizontal north and east gradients every 6 h at both stations. The change of the UT1 estimates is at the 10 μs level with maximum differences of up to 50 μs, which is clearly above the formal uncertainties of the UT1 estimates (between 5 and 20 μs). Spectral analysis reveals that delays from direct ray-tracing for the station Tsukuba add significant power at short periods (1–2 weeks) w.r.t. the state-of-the-art approach, and comparisons with length-of-day (LOD) estimates from Global Positioning System (GPS) indicate that these ray-traced delays slightly improve the UT1 estimates from Intensive sessions.  相似文献   

The Kepler Mission: Astrophysics and Eclipsing Binaries     

D. Koch  W. Borucki  G. Basri  T. Brown  D. Caldwell  J. Christensen-Dalsgaard  W. Cochran  E. Dunham  T. N. Gautier  J. Geary  R. Gilliland  J. Jenkins  Y. Kondo  D. Latham  J. Lissauer  D. Monet 《Astrophysics and Space Science》2006,304(1-4):391-395

The Kepler Mission is a photometric space mission that will continuously observe a single 100 square degree field of view (FOV) of the sky of more than 100,000 stars in the Cygnus-Lyra region for four or more years with a precision of 14 parts per million (ppm) for a 6.5 hour integration including shot noise for a twelfth magnitude star. The primary goal of the mission is to detect Earth-size planets in the habitable zone of solar-like stars. In the process, many eclipsing binaries (EB) will also be detected. Prior to launch, the stellar characteristics will have been determined for all the stars in the FOV with K<14.5. As part of the verification process, stars with transits (about 5%) will need to have follow-up radial velocity observations performed to determine the component masses and thereby separate grazing eclipses caused by stellar companions from transits caused by planets. The result will be a rich database on EBs. The community will have access to the archive for uses such as for EB modeling of the high-precision light curves. A guest observer program is also planned for objects not already on the target list.  相似文献   

A New Parametrization of Mixing Length in an Urban Canopy Derived from a Large-Eddy Simulation Database for Tokyo   总被引：1，自引：1，他引：0  

H. Kondo  A. Inagaki  M. Kanda 《Boundary-Layer Meteorology》2015,156(1):131-144

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Characteristics and formation of rain forest soils derived from late Quaternary basaltic rocks in Leyte,Philippines     

Ian A. Navarrete  Kiyoshi Tsutsuki  Victor B. Asio  Renzo Kondo 《Environmental Geology》2009,58(6):1257-1268

This study was conducted to evaluate the physical, chemical, and mineralogical characteristics of rain forest soils derived from late Quaternary basaltic rocks in Leyte, Philippines. Four sites along a catena were selected at an elevation of 75–112 m above sea level with an average annual rainfall of 3,000 mm and an average temperature of 28°C. Results indicate that the soils are deep, clayey, and reddish in color, which is indicative of the advanced stage of soil development. They also posses excellent physical condition (friable and highly porous) although they are plastic and sticky when wet as is usual for clayey soils. In terms of chemical characteristics, the soils are acidic with low CEC values and generally low in organic matter and nutrient contents. The clay mineralogy of the soils is dominated by halloysite and kaolinite with minor amounts of goethite and hematite, and they also have generally high dithionite-extractable Fe contents confirming the advanced stage of their development. The soils in the more stable slope positions (PL-1, PL-2, and PL-4) have generally similar characteristics and appeared more developed than the one in the less stable position (PL-3). The most important pedogenic processes that formed the soils appear to be weathering, loss of bases and acidification, desilification, ferrugination, clay formation and translocation, and structure formation. The nature of the parent rock and climatic conditions prevailing in the area as well as slope position appear to have dominant effects on the development of the soils.  相似文献   

The SOLAR-A mission: An overview     

Y. Ogawara  T. Takano  T. Kato  T. Kosugi  S. Tsuneta  T. Watanabe  I. Kondo  Y. Uchida 《Solar physics》1991,136(1):1-16

The SOLAR-A spacecraft is to be launched by the Institute of Space and Astronautical Science, Japan (ISAS) in August, 1991. As a successor of HINOTORI, this mission is dedicated principally to the study of solar flares, especially of high-energy phenomena observed in the X- and gamma-ray ranges. The SOLAR-A will be the unique space solar observatory during the current activity maximum period (1989–1992). With a coordinated set of instruments including hard X-ray and soft X-ray imaging telescopes as well as spectrometers with advanced capabilities, it will reveal many new aspects of flares and help better understand their physics, supporting international collaborations with ground-based observatories as well as theoretical investigations. An overview of this mission, including the satellite, its scientific instruments, and its operation, is given in this paper. Also the scientific objectives are briefly discussed.After the launch the name of SOLAR-A has been changed to YOHKOH.  相似文献   

Possible solar neutron events recorded by the ground-based neutron monitor     

Yoshimori  M.  Takahashi  K.  Wada  M.  Kusunose  M.  Kondo  I. 《Solar physics》1987,113(1-2):319-325

Solar Physics - Possible solar neutron emission associated with five SMM gamma-ray events on 7 June 1980, 21 June 1980, 6 November 1980, 26 November 1982 and 25 April 1984 was found from analysis...  相似文献