Showing papers in "Geographical reports of Tokyo Metropolitan University in 2011"

Analysis of temperature and wind distribution using high-resolution data in Kanto Plain on August 16, 2007

Abstract: The Automated Meteorological Data Acquisition System (AMeDAS) stations that observed the daily maximum temperature on August 16, 2007, to be approximately 40°C were limited to the northern Kanto Plain. However, numerical studies (Watarai et al. 2009; Shinohara et al. 2009) indicated that the high-temperature area was located at the boundary between Saitama Prefecture and the Tokyo Metropolis. To verify the existence of an area of elevated temperature that was identified by the numerical study, this study analyzed the temperature distributions in the Kanto Plain using high-density temperature data (E-METROS). A boundary between the southerly and northerly winds was located in the southern Saitama Prefecture, and the temperature was elevated just north of this boundary. According to the E-METROS network, the area where the daily maximum temperature exceeded 40 °C was located near Kumagaya and the central Kanto Plain. Thus, the spatial scale of this area was somewhat smaller than that of the area observed by the AMeDAS stations. It is thought that this elevated temperature was influenced by the sea-breeze front that merged at the boundary between the northerly and southerly winds at 14:00 Japan Standard Time (JST). The convergence also became strong near the boundary. Because the convergence strengthened, down flow in front of the sea-breeze front may also have strengthened. The high-temperature area located at the central Kanto Plain may have been caused by enhanced downward flow in front of the sea-breeze front.

Observational study on regional climate of Izu Oshima Island, Tokyo

Abstract: To examine the regional climate of Izu Oshima Island, Tokyo, we observed precipitation and temperature from June 2009 to September 2010 in various places across the island. Using our observational data, AMeDAS (Automated Meteorological Data Acquisition System) data from the Japan Meteorological Agency and precipitation data from the Tokyo Metropolitan Government Bureau of Construction, we analyzed the altitudinal increase of precipitation and the spatial distribution of temperature associated with the prevailing winds. The rainfall amount increased with altitude due to the altitudinal increase in rainfall frequency, although the rainfall intensity did not increase with altitude. The prevailing wind direction over Izu Oshima Island is northeast (NE) or southwest (SW). When NE-wind days and SW-wind days were selected, the mean temperature in the leeward side of the island was found to be higher than that on the windward side.