Dynamical impact of anomalous East-Asian winter monsoon on zonal wind over the equatorial western Pacific

Abstract Zonal wind anomaly over the equatorial western Pacific plays an important role in the occurrence of ENSO. The mechanism to produce zonal wind anomaly over the equatorial western Pacific is studied in this paper. It is shown clearly that zonal wind anomaly over the equatorial western Pacific is closely related to the anomaly of EastAsian winter monsoon. Anomalous strong （weak） East-Asian winter monsoon can excite not only the westerly （easterly）anomaly over the equatorial western Pacific but also a cyclonic （an anticyclonic） circulation over the east of the Philippines. The above anomalous circulation results from dynamical impacts of anomalous pressure pattern due to the East-Asian winter monsoon. Because there is westward （eastward） pressure gradient over the equatorial western Pacific, i.e. there is αp/αx 〈 0 （〉 0）, during strong （weak） East-Asian winter monsoon.     

太平洋地区地球主磁场长期变化特征的研究

研究太平洋地区主磁场的长期变化特征,对揭示该地区的“偶极子窗”的时间演变和长期变化规律有重要意义.作者使用最新的国际地磁参考场IGRF13模型资料,分析1900—2020年期间太平洋地区主磁场的长期变化特征.结果表明1900—2020年太平洋地区主磁场的空间展布符合“太平洋偶极子窗”的分布特征.该地区主磁场的长期变化在赤道以北为缓慢变化,以南则是较快变化.偶极子场成分变化缓慢,非偶极子场成分变化较快.非偶极子场的长期变化以西向漂移为主,但各分量的西漂速率有显著的差异.垂直分量（Z）和北向分量（X）的西漂速率分别为0.23°/a和0.21°/a,均接近于0.2°/a的全球非偶极子西漂速率;东向分量（Y）的西漂速率为0.17°/a,低于全球非偶极子西漂速率. Y分量的长期变化在34°N附近发生扭曲并且在北太平洋表现为缓慢东漂,这一长期变化特征可能与太平洋北部的30°N和45°N之间在核幔边界处存在的古板块的俯冲过程有关.     

西太平洋洋底高原内部结构与形成演化

洋底高原是在深海盆地中最显著的大火成岩省,记录着海洋大规模的岩浆活动,对研究地壳结构、板块构造、地幔动力学乃至地球演化历史都具有重要意义。西太平洋是洋底高原分布最密集的区域,是研究洋底高原内部结构与形成演化的最佳场所。选取西太平洋中最具代表性的6座洋底高原——沙茨基海隆、赫斯海隆、麦哲伦海隆、翁通爪哇高原、马尼希基高原以及希古朗基高原,通过对这6座洋底高原地质概况的简要描述,归纳近年来获得的地球物理与地球化学重要观测结果,揭示其内部结构的共性,包括大面积地形隆起、异常厚的地壳、异常负的地幔重力异常以及形成于洋中脊之上或者附近的位置特征;探索了其形成机制,即地幔柱与洋中脊的相互作用可能是洋底高原的主要成因。     

Analysis of thiols by microchip capillary electrophoresis for in situ planetary investigations

The detection of thiols on extraterrestrial bodies could provide evidence for life, as well as a host of potential prebiological or abiological processes. Here, we report a novel protocol to analyze organic thiols by microchip CE with LIF detection. Thiols were labeled with Pacific Blue C5 maleimide and analyzed by MEKC. The separation buffer consisted of 15 mM tetraborate pH 9.2 and 25 mM SDS. The optimized method provided LODs ranging from 1.4 to 15 nM. The method was validated using samples collected from geothermal pools at Hot Creek Gorge, California, which were found to contain 2‐propanethiol and 1‐butanethiol in the nanomolar concentration range. These samples serve as chemical analogues to material potentially present in the reducing environment of primitive Earth and also at sulfurous regions of Mars. Hence, the protocol developed here enables highly sensitive thiol analysis in samples with complexity comparable to that expected in astrobiologically relevant extraterrestrial settings. This new protocol could be readily added to the existing suite of microfluidic chemical analyses developed for in situ planetary exploration; all that is required is the incorporation of two new reagents to the payload of an existing instrument concept.     

西北太平洋打转台风的时空规律

以西北太平洋打转台风(分为顺时针与逆时针两类)为例,研究了1949～2011年期间打转台风的时空规律.结果表明:打转台风主要发生在洋面,主要分布在110°E～150°E、10°N～30°N区域范围内.台风打转后的发展方向以偏北为主,也有一部分打转后西行,绝大多数顺时针打转台风的打转中心位置随纬度的增加而偏东.打转台风生成的高发期为7～10月,占总数的73.7%,8月份生成次数最多,2月份生成次数最少.我国的南海区域和菲律宾以东洋面是生成打转台风的两个高频区,夏季和秋季是打转台风活动的高发期,夏季的打转台风生成次数稍低于秋季,但是其深入内陆的范围广于秋季,并且台风打转中心位置在夏季达到最北.     

Gravity at sea--A memoir of a marine geophysicist

A history of studies on the gravity measurements at sea in Japan is reviewed with an emphasis on the contribution of the author. The first successful measurements at sea were made in 1923 by Vening Meinesz in the Netherlands using the pendulum apparatus installed in a submarine. However, the gravity measurements using a submarine are not convenient because the access to a submarine is limited. Professor Chuji Tsuboi made a number of unsuccessful attempts at developing a gravity meter that can be operated on a normal surface ship by reducing the noise by minimizing the motion of the gravity meter through a mechanical design. I have chosen a new approach toward the measurements of gravity on a surface ship by simplifying the mechanical part using a string gravity meter that was installed directly on a vertical gyroscope in combination with the numerical and/or electronic reduction of noises. With this gravity meter TSSG (Tokyo Surface Ship Gravity Meter), we firstly succeeded in measuring gravity at sea onboard a surface ship in July 1961 and the measurements have been extended to the northwestern Pacific and beyond. The results reveal the fine structures of gravity field in and around trenches that provide important clues as to a number of geodynamic issues including the nature of the trench-trench interaction and the interaction of trenches with seamounts.     

Relationship between real meridional volume transport and Sverdrup transport in the North Subtropical Pacific

The meridional volume transport (MVT) associated with the wind-driven gyre is an important index for ocean general circulations because it is closely related to the poleward oceanic heat transport. In particular, the mass transport by the subtropical gyre…     

Deposition of Sulfate,Chloride and Sodium at Japanese Meteorological Observatories and on the Western North Pacific

Abstract

A simple plastic sampler was tested to get the information on the deposition amount of chemical components throughout Japan and the neighbouring regions. Polypropylene cylinders of diameter 117 mm which contained 300ml pure water were set in the observation fields and kept open for one month. At the end of the month the samplers were covered with caps and sent to Meteorological College, Kashiwa, Chiba. The sample solutions were filtered through Millipore filter (0.45μm pore size) and used for the determination by ion chromatography, atomic absorption and flame emission analyses. Monthly deposition amounts of sulfate, chloride and sodium ions were determined simultaneously at 21 Japanese meteorological observatories in June and October 1987. Similar samples were also set on the upper deck of RV Ryofu-maru for 4–7 days during cruises across the western North Pacific in 1987 and 1988. The deposition amount of SO₄(excess) (SO₄–Na × SO₄(seasalt)/Na(seasalt)) was calculated. The strongest source regions of SO₄(excess) were found to be on the Pacific side of Honshu, where big cities such as Tokyo and Osaka are situated. The deposition amount generally decreased depending upon the distance from these sources. Another strong source region of SO₄ (excess) was Kagoshima. It is suggested that the deposition at this station was influenced by the volcanic activity of Mt. Sakurajima, because the deposition amount of Cl(excess) was also found to be high, reflecting the composition of the volcanic gases of this region.     

全球气候变暖对西北太平洋热带气旋的影响

通过对全球地面温度与西北太平洋热带气旋的分析表明：随着全球气候变暖，西北太平洋上热带气旋的频数减少，极端中心气压增加、极端最大中心风速减小，即热带气旋强度减弱；在增暖最快的20世纪90年代，这种关系尤为突出。     

西北太平洋环流和海温数值模拟

基于Ecom-si建立了一个西北太平洋海洋数值模式,综合考虑了侧边界通量、海表面风应力、热通量、蒸发和降水等因素,模拟并分析了西北太平洋环流和海温的基本特征.模式验证结果表明,模式计算的海温与日本2008年西北太平洋实测温度走航断面资料吻合良好.模式再现了低纬度海区表层自东向西流动的北赤道流、强西边界流黑潮、东海的台湾...