(Tenki is the bulletin journal of the Meteorological Society of Japan in Japanese.)
TENKI, Vol. 56, No. 4, pp. 203-216, 2009
A trial of joint activity of meteorology with music in a primary school was performed on the topic of the rapid seasonal increase in air temperature and the relating "seasonal feeling" from March to April around Japan.
Firstly, features of the rapid seasonal increase in surface air temperature from March to April pointed out by H. Kato and K. Kato (2006) was reviewed, adding the new analyses on the seasonal change in the dominant surface pressure systems around Mongolia at that time based on the daily surface weather maps from 1981 to 1990. We also examined 506 of the Japanese children songs and school ones. Most of the songs which treat with spring were associated with natural sight or human lives around the period from March to April.
Based on these results, the successive three classes were carried out for 36 students in the fifth grade of Kotoura-Higashi Primary School in Kurashiki-city, including the practice of musical expression of the Japanese children's songs relating to the spring season mentioned above. In the first class, the activity for finding the meteorological aspects on the rapid temperature rise around the beginning of April was performed, in relation to the "seasonal feeling". In the latter half of the present paper, results of the first class are reported.
(Tenki is the bulletin journal of the Meteorological Society of Japan in Japanese.)
TENKI, Vol. 56, No. 4, pp. 217-222, 2009
In order to investigate the effects of the sea surface temperature (SST) of the Tosa Bay being influenced strongly by the Kuroshio on the behavior of sea breeze over the Kochi plain, 5 years weather data collected from 2003 to 2007 at three AMEDAS observation points of Aki, Nissho and Gomen having least influences of a heat island effects were analyzed. These recent results were then compared with the past sodar observation data made about 18 years ago (1989 to 1990) at the ABO (Atmospheric Boundary-Layer Observatory) observation point of Kochi University, as well as additional comparisons with the data of Nissho and of AMEDAS at Aki and Gomen. As a result, the intrusion of sea breeze delayed about 21 minutes on average in recent 5 years compared to the past averages, although the intruding speed of sea breeze did not show any significant difference such as 3.1 km/h in recent years compared to 2.9 km/h in 18 years ago.
(Tenki is the bulletin journal of the Meteorological Society of Japan in Japanese.)
TENKI, Vol. 56, No. 5, pp. 353-365, 2009
This study developed the warning criteria of gusts accompanied by a cold front in the coastal regions of the Sea of Japan, based on radar echo data in the winter (from November to March next year), for train operation control. Criteria for detection of a parent cloud which has the possibility of gust occurrence are as follows:
(1) The existence of 10 grid points (in a 1-km-mesh) of an echo intensity over 80 mm/h,
(2) The echo top height is more than 6 km.
These criteria could detect all of three gusts which caused injuries and fatalities in the coastal regions of the Sea of Japan and the Sea of Okhotsk during the 2005-2008 winter seasons, and could detect four of the seven gusts in these areas during these seasons.
This study designed the following train operation control method using the above criteria. When the radar echo satisfying the criteria appears, a warning area is specified as an area within a radius of approximately 38 km from the radar echo to the directions of the north to the southeast. If there is a railway line within the warning area, a dispatcher immediately stops trains in the area. When this method is applied to the Niitsu-Sakata section of the Uetsu Line and the Niigata-Shibata section of the Hakushin Line, these lines are included within the warning area for an average of 150 minutes and 4.0 times per year during the 2005-2008 winter seasons. Based on this verification, train operation control using this method has been conducted on a trial basis in these sections since January 28, 2008.
(Tenki is the bulletin journal of the Meteorological Society of Japan in Japanese.)
TENKI, Vol. 56, No. 7, pp. 495-507, 2009
Aiming at deconvolution of the dust event into local and remote elements, physical and chemical aerosol observations were carried out at the Meteorological Research Institute in Tsukuba, Japan in spring of 2006. During the observation there were two remarkable dust events with the maximum aerosol mass concentration attained to a few hundred μg/m3 (hourly value), which were selected for close scrutiny. Based on the meteorological observations over the Japanese islands, backward-trajectory analysis and the CTM calculations, it was concluded that they had different origins. One was Asian dust transported from the continent (Kosa) and the other was blowing dust from neighborhood. Therefore, physical and chemical characteristics of these were compared. For the case of the blowing dust event during its evolution (the dust mass was increasing), number concentrations of larger particles increased remarkably, while those increased concurrently by all particle size bins of the optical particle counter for the Kosa event. In the analysis of the water soluble ions, the Kosa dust showed about twice higher concentrations as well as the ratio of nss-Ca2+ and nss-SO42- to the total dust mass compared to those of the local blowing dust. NO3- also exhibited significantly high concentration for the Kosa dust. Further accumulation of such differences in physical and chemical nature of the dust may bring a potential criterion to distinguish the Kosa and the local blowing dust events over Japan.
(Tenki is the bulletin journal of the Meteorological Society of Japan in Japanese.)
TENKI, Vol. 56, No. 8, pp. 627-635, 2009
Statistical approaches were applied to the heat island phenomena occurring in Tokyo Metropolis in order to clarify how the diurnal temperature changing patterns vary according to season and weather. For each of the selected day, principal component analysis is applied to the temperature data that were measured every hour at 100 locations in Tokyo, and the diurnal temperature changing patterns are extracted. Days are selected from all the four seasons, i.e. spring, summer, autumn, and winter. Also, days from sunny, cloudy, and rainy days are selected.
By interpreting the obtained principal components and examining the geographical distributions of the principal component scores of the measured locations, the days are classified into three groups: a) sunny days in mid-summer, b) sunny days except in mid-summer, and c) cloudy days and rainy days. From the characteristics of these groups, it is found that the urban heat island phenomenon occurring in Tokyo appears differently according to season and weather in terms of diurnal temperature variation.
(Tenki is the bulletin journal of the Meteorological Society of Japan in Japanese.)
TENKI, Vol. 56, No. 9, pp. 755-761, 2009
A new method was developed for dealiasing Doppler velocities confined to in narrower azimuthal intervals collected in PPI (Plan Position Indicator) mode by a successive application of software-based two different algorithms proposed by Hennington (1981) and Yamada and Chong (1999). At first, the method of Hennington (1981) is employed to assign a Nyquist interval number to each valid velocity datum using a given vertical profile of horizontal winds. Each range bin without valid velocity datum is filled with a radial wind component computed from the wind profile, as a temporary datum. The dealiased velocities in the first step are subject to the correction by the algorithm of Yamada and Chong (1999) in order to mainly perform a quality control of Doppler velocities. In this second step, the essence is to derive a second-order Fourier development from the valid and temporary data ensemble in order to ensure the appropriate estimation of the Fourier coefficients at least at a gate which contains maximum number of valid velocity data. The performance of the newly developed method has been demonstrated by the application of this new technique to observed data collected for a deep tropical convective system.