All issues
Volume 62, Issue 2
June
Displaying 1-4 of 4 articles from this issue
- |<
- <
- 1
- >
- >|
Full Papers
-
Sanghun LEE, Shuji YAMAKAWA2006 Volume 62 Issue 2 Pages 53-63
Published: 2006
Released on J-STAGE: March 30, 2007
JOURNAL FREE ACCESSThis study identifies different wintertime climatic regions in South Korea based on precipitation and snowfall data. We investigated the primary features of wintertime climate via cluster analysis of monthly precipitation and snowfall data. Regional classifications are based on a comparison of both daily data and the top ten daily totals for precipitation and snowfall for each region over the last 30 years. Regional classification by precipitation and by precipitation mechanism leads to the recognition of six climatic areas, while local classification on the basis of snowfall defined six areas, and local classification on the basis of snowfall mechanism defines five areas. Empirical orthogonal function (EOF) analysis supports the regional classification. Each of the classified areas has a characteristic distribution of atmospheric pressure. A close relationship exists between the distribution of classified areas and geographical features. Additionally, the ocean around South Korea plays an important role in wintertime climate.View full abstractDownload PDF (1344K) -
Jun'ichi TESHIMA, Yosuke HIRAYAMA, Tetsuo KOBAYASHI, Hiroyuki CHO2006 Volume 62 Issue 2 Pages 65-74
Published: 2006
Released on J-STAGE: March 30, 2007
JOURNAL FREE ACCESSEvapotranspiration (ET) from a small area on a grass-covered slope with an inclination of 8.7 degrees was estimated using the bucket-with-a-bottom-hole (BBH) model of soil hydrology. The BBH model has seven parameters, two of which were determined by experiment. The other five parameters were identified by trial and error, based on the decision criterion that the root mean square (RMS) of the difference between the predicted and measured values of soil moisture contained in the active soil surface layer (ASSL) takes a minimum value. Estimates of ET made using the BBH model were compared to the measurements taken using the Bowen ratio method. If the measurements can be regarded as the true values, the results are summarized as follows:
- The estimates of annual ET made using the BBH model are reliable, although they may be somewhat smaller than the true values.
- The estimates of monthly ET made using the BBH model can be used in analyses of water balance if an accuracy of better than ±10% is not required.
- The accuracy of estimating daily ET using the BBH model was about ±60%.
The main characteristics of water balance on the grass-covered slope obtained using the BBH model were summarized as follows:
- Only less than one quarter of precipitation was allotted to ET on the slope.
- Spatial variation in ET within an area several meters in size on the grass-covered slope was shown to be rather large, especially in the summer months. During the winter months, however, it was insignificant. The variation in annual ET among the three observation points within the area was about 20% as great as their mean.View full abstractDownload PDF (1041K) -
Kenji SUZUKI, Yuki OHNISHI, Seiji HAYAKAWA2006 Volume 62 Issue 2 Pages 75-81
Published: 2006
Released on J-STAGE: March 30, 2007
JOURNAL FREE ACCESSIn this study we examined winter precipitation patterns in Yamaguchi, a relatively warm region of Japan, using Japan Meteorological Agency weather radar data from 1989 to 1998. During cold air outbreaks, radar echoes commonly revealed the formation of cloud streets. We classified band-shaped patterns of cloud streets into four different groups on the basis of band-transverse directions. The WNW and NW band-transverse directions were dominant, accounting for 70% of all occurrences. The band-transverse directions corresponded with the 850 hPa wind direction, as was similarly observed in northern Japan. Local winter precipitation was strongly related to the band-transverse direction of radar echoes. High concentrations of radar echoes were characterized by their directions in relation to the orientation of the coastline.View full abstractDownload PDF (880K) -
Hiroaki KOMODA, Tetsuo KOBAYASHI, Makito MORI, Takemasa KANEKO2006 Volume 62 Issue 2 Pages 83-91
Published: 2006
Released on J-STAGE: March 30, 2007
JOURNAL FREE ACCESSObservations of cold-air-drainage (CAD) winds were made on a geometrically simple grass-covered slope of Mt. Kuju (Oita, 1,787 m ASL), with the average inclination of 7°. Observations were made on 12 nights, with the results summarized as follows:
(a) The direction of CAD winds at an observation station differed from that at another station on the slope, and the change in the angle of direction between the two stations had a bimodal frequency distribution.
(b) When a mixed layer is capped by a strong inversion, CAD winds accelerated on the leeward slope and decelerated on the windward slope.
(c) When ambient potential temperature increased linearly with altitude, CAD winds decelerated on the leeward slope and accelerated on the windward slope.
The mechanisms responsible for these phenomena are shown, based on a few hypotheses.View full abstractDownload PDF (2205K)
- |<
- <
- 1
- >
- >|