Submarine eruption of the Myôjin reef     

R. Morimoto 《Bulletin of Volcanology》1960,23(1):151-160

  相似文献   

Green’s function approach for calibrating tides in a circulation model for the East Asian marginal seas     

Jae-Hong Moon  Naoki Hirose  Akihiko Morimoto 《Journal of Oceanography》2012,68(2):345-354

A simple effective method of inverse estimation provided by model Green’s functions is examined to calibrate tides in a regional circulation model for the East Asian marginal seas. The Green’s function optimization derived by perturbing the model parameters significantly improves the estimate relative to observation as compared with baseline integration. Among the optimized model parameters, the largest effects on cost function reduction come first from the harmonic constant of M₂ along the open boundaries with the optimized values of 89.7 ± 0.8% for amplitude, and second from the bottom friction with the optimized value of (3.06 ± 0.08) × 10⁻³.  相似文献   

Biweekly periodic variation of the Kuroshio axis northeast of Taiwan as revealed by ocean high-frequency radar     

Daisuke Takahashi  Xinyu Guo  Akihiko Morimoto  Shoichiro Kojima 《Continental Shelf Research》2009,29(15):1896-1907

An analysis of surface current data obtained from 2002 to 2005 using long-range high-frequency radar provides the first evidence for the presence of biweekly (11–14 day) periodic variations of the Kuroshio axis northeast of Taiwan. This analysis clarifies the spatiotemporal characteristics of these variations and reveals that cyclonic/anticyclonic eddies propagating along the shelf slope from the vicinity of the deep channel east of Taiwan induce these variations northeast of Taiwan. The behavior of the cyclonic/anticyclonic eddies on the shelf slope is well explained by 2nd-mode interior shelf waves advected by the Kuroshio's mean flow. Remote effects from the vicinity of the deep channel east of Taiwan, or from outside the East China Sea, are believed to play an important role in the generation of these biweekly periodic variations of the Kuroshio axis northeast of Taiwan. Moreover, on the shelf slope, these variations cause an onshore current across the shelf slope, suggesting topographically controlled upwelling. Therefore, the biweekly periodic variations of the Kuroshio axis northeast of Taiwan might contribute not only to the onshore transport of Kuroshio surface water but also to transport nutrient-rich Kuroshio subsurface water onto the shelf in the East China Sea.  相似文献   

A Low-Power High-Resolution Broad-Band Radar Using a Pulse Compression Technique for Meteorological Application     

Mega  T. Monden  K. Ushio  T. Okamoto  K. Kawasaki  Z.-I. Morimoto  T. 《Geoscience and Remote Sensing Letters, IEEE》2007,4(3):392-396

A new high-resolution Ku-band Doppler radar for meteorological applications has been developed. With the new system design, the radar can accurately measure the radar reflectivity factor with 4-m resolution over a range from 40 m to several kilometers for 100-mW power using a pulse compression technique. Details of the system design, signal processing algorithm, and data acquisition procedures are described. To demonstrate the accuracy of the system, the radar reflectivity measurements are compared with the Joss-Waldvogel disdrometer measurements, and fairly good agreement is shown. The ability of the system to capture the backscattered signal and Doppler spectrum from rain volume at low altitude with high resolution is demonstrated for both convective- and stratiform-type rain events.  相似文献   

Characteristics of water mass under the surface mixed layer in Tsushima Straits and the southwestern Japan Sea in autumn   总被引：1，自引：0，他引：1  

Tetsutaro Takikawa  Akihiko Morimoto  Goh Onitsuka  Atsushi Watanabe  Masatoshi Moku 《Journal of Oceanography》2008,64(4):585-594

Two different cold waters were found under the surface mixed layer in Tsushima Straits and the southwestern Japan Sea in autumn 2004. One is cold saline water with a low concentration of dissolved oxygen, and the other is cold less saline water with a high concentration of dissolved oxygen. The older saline water originates from the bottom of the East China Sea, strongly influenced by the Kuroshio water with high salinity. The bottom density in the eastern channel of the Tsushima Straits is coincident with that of the East China Sea in autumn, corresponding to the season when the cold saline water was frequently found in the Tsushima Straits. The newer less saline water originates from the front of Tsushima Warm Current between the Tsushima Warm Current water and the surface cold water in the Japan Sea. This water is formed by subduction above the isopycnal surface from the front of the Tsushima Warm Current.  相似文献