著者
Hiroyuki Ariyama Keisuke Mori
出版者
The Japanese Society of Systematic Zoology
雑誌
Species Diversity (ISSN:13421670)
巻号頁・発行日
vol.28, no.1, pp.31-44, 2023-01-26 (Released:2023-01-26)
参考文献数
30
被引用文献数
1

Two distinctive species of Amphipoda are described from the Ariake Sea in Japan. Scutischyrocerus japonicus sp. nov. (Family Ischyroceridae) is characterized by the cylindrical shape and the shield-like coxae 2–5. This new species differs from S. scutatus Myers, 1995 in the uropods with peduncles bearing many plumose setae. In the second species, Ledoyerella clavata (Hirayama, 1984) comb. nov. (Family Kamakidae), the lateral cephalic lobe is strongly produced, and the gnathopods 1, 2 of both sexes are the same size, with the propodus being almost as long as the carpus. This species can be distinguished from its congeners by the heavily setose posterior margins of pereopods 6, 7 bases. Ledoyerella spinosa Ren, 2006 is synonymized with this species.
著者
Keisuke MORI Tomonori SATO
出版者
Meteorological Society of Japan
雑誌
気象集誌. 第2輯 (ISSN:00261165)
巻号頁・発行日
vol.92, no.4, pp.327-346, 2014 (Released:2014-09-26)
参考文献数
39
被引用文献数
3 9

This study investigated the spatiotemporal characteristics of high-temperature events in Hokkaido, Japan, using observational data of 26 years. Statistical analyses revealed that the annual mean frequency of these events was lower (higher) at stations on the western (eastern) side of Hokkaido. The frequency of these events showed clear seasonal variation with two distinct peaks occurring in January and May. In addition, the local time of the high-temperature onset was strongly dependent on the season; the onset occurred more frequently from 1600 to 0400 Japan Standard Time (JST) in January and from 0700 to 1300 JST in May. The seasonal dependence mechanism of the high-temperature onset was investigated in eastern Hokkaido, where the frequencies of both January and May high-temperature events were the highest. In January, an extratropical cyclone passage caused intensified warm advection and increased precipitable water vapor, leading to weakened radiative cooling during the night. In May, the high-temperature events were triggered by two different mechanisms related to solar insolation. The first mechanism is explained by dynamic foehn, which forms the subsidence of the high potential temperature layer on the lee of mountains. However, the nocturnal inversion layer prevented vertical mixing of the foehn-induced warm air aloft and cold air near the ground. The surface air temperature dramatically increased after sunrise when the nocturnal inversion layer disappeared. The second mechanism is explained by the combination of airflow diabatically heated by surface sensible heat flux and dynamic foehn. Therefore, solar insolation is the key factor that controlled the diurnal variation in high-temperature events in May.