Impact of biomass burning on Ocean water quality in Southeast Asia through atmospheric deposition: Field observations

10.5194/acp-10-11323-2010Atmospheric Chemistry and Physics102311323-1133

Modelling of tsunami-like wave run-up, breaking and impact on a vertical wall by SPH method

Natural Hazards and Earth System Sciences13123457-346

Storm surges in the Singapore Strait due to winds in the South China Sea

Among the semi-enclosed basins of the world ocean, the South China Sea (SCS) is unique in its configuration as it lies under the main southwest-northeast pathway of the seasonal monsoons. The northeast (NE) monsoon (November–February) and southwest (SW) monsoon (June–August) dominate the large-scale sea level dynamics of the SCS. Sunda Shelf at the southwest part of SCS tends to amplify Sea Level Anomalies (SLAs) generated by winds over the sea. The entire region, bounded by Gulf of Thailand on the north, Karimata Strait on the south, east cost of Peninsular Malaysia on the west, and break of Sunda Shelf on the east, could experience positive or negative SLAs depending on the wind direction and speed. Strong sea level surges during NE monsoon, if coincide with spring tide, usually lead to coastal floods in the region. To understand the phenomena, we analyzed the wind-driven sea level anomalies focusing on Singapore Strait (SS), laying at the most southwest point of the region. An analysis of Tanjong Pagar tide gauge data in the SS, as well as satellite altimetry and reanalyzed wind in the region, reveals that the wind over central part of SCS is arguably the most important factor determining the observed variability of SLAs at hourly to monthly scales. Climatological SLAs in SS are found to be positive, and of the order of 30 cm during NE monsoon, but negative, and of the order of 20 cm during SW monsoon. The largest anomalies are associated with intensified winds during NE monsoon, with historical highs exceeding 50 cm. At the hourly and daily time-scales, SLA magnitude is correlated with the NE wind speed over central part of SCS with an average time lag of 36–42 h. An exact solution is derived by approximating the elongated SCS shape with one-dimensional two-step channel. The solution is utilized to derive simple model connecting SLAs in SS with the wind speeds over central part of SCS. Due to delay of sea level anomaly in SS with respect to the remote source at SCS, the simplified solutions could be used for storm surge forecast, with a lead time exceeding 1 day.Singapore. National Research Foundation (Singapore MIT Alliance for Research and Technology)Singapore-MIT Alliance for Research and Technology. Center for Environmental Sensing and Modelin

Design of Field Experiments for Adaptive Sampling of the Ocean with Autonomous Vehicles

Due to the highly non-linear and dynamical nature of oceanic phenomena, the predictive capability of various ocean models depends on the availability of operational data. A practical method to improve the accuracy of the ocean forecast is to use a data assimilation methodology to combine in-situ measured and remotely acquired data with numerical forecast models of the physical environment. Autonomous surface and underwater vehicles with various sensors are economic and efficient tools for exploring and sampling the ocean for data assimilation; however there is an energy limitation to such vehicles, and thus effective resource allocation for adaptive sampling is required to optimize the efficiency of exploration. In this paper, we use physical oceanography forecasts of the coastal zone of Singapore for the design of a set of field experiments to acquire useful data for model calibration and data assimilation. The design process of our experiments relied on the oceanography forecast including the current speed, its gradient, and vorticity in a given region of interest for which permits for field experiments could be obtained and for time intervals that correspond to strong tidal currents. Based on these maps, resources available to our experimental team, including Autonomous Surface Craft (ASC) are allocated so as to capture the oceanic features that result from jets and vortices behind bluff bodies (e.g., islands) in the tidal current. Results are summarized from this resource allocation process and field experiments conducted in January 2009.Singapore. National Research Foundatio

Impact of mass redistribution on regional sea level changes over the South China Sea shelves

This study investigates long-term sea level changes in the South China Sea (SCS) using a validated high-resolution regional ocean model simulation for the Maritime Continent. The contributions of ocean mass redistribution and steric sea level are examined to understand the sea level variations. The ocean bottom pressure (OBP) serves as an indicator of sea level variations linked to alterations in ocean mass flux. The OBP accounts for over 80% of the total sea level change over the shelves, while the steric sea level emerges as the dominant factor, contributing over 50% to the sea level change in the deep SCS. Luzon Strait transport shows a weakening trend in the last six decades, resulting in higher heat accumulation and larger steric expansion in the deep SCS. The ocean mass redistribution acts as a mechanism to balance the contrasting steric induced sea level changes over the deep SCS and shallow continental shelves

Multi-layer model simulation and data assimilation in the Serangoon Harbor of Singapore

In June of 2009, a sea trial was carried out around Singapore to study and monitor physical, biological and chemical oceanographic parameters. Temperature, salinity and velocities were collected from multiple vehicles. The extensive data set collected in the Serangoon Harbour provides an opportunity to study barotropic and baroclinic circulation in the harbour and to apply data assimilation methods in the estuarine area. In this study, a three-dimensional, primitive equation coastal ocean model (FVCOM) with a number of vertical layers is used to simulate barotropic and baroclinic flows and reconstruct the vertical velocity structures. The model results are validated with in situ ADCP observations to assess the realism of the model simulations. EnKF data assimilation method is successively implemented to assimilate all the available ADCP data, and thus correct for the model forecast deficiencies.Singapore. National Research FoundationSingapore-MIT AllianceSingapore-MIT Alliance. Center for Environmental Sensing and Monitorin

Multi-vehicle oceanographic feature exploration

URL to conference page. Scroll down to 2009 conference (June 21-26), click "Paper and session list," and search under Patrikalakis' name.Oceanographic features such as jets and vortices are often found downstream of obstacles and landforms such as islands or peninsulas. Such features have high spatial and temporal variability and are, hence, interesting but difficult to measure and quantify. This paper discusses an experiment to identify and resolve such oceanographic features in Selat Pauh, in the Straits of Singapore. The deployment formation for multiple robotic vehicles (Autonomous Surface Craft - ASC), the measurement instruments, and the algorithms developed in extracting oceanographic field variables are described. These were based on two ocean field predictions from well-known geophysical flow dynamic models. Field experiments were carried out and comparison of the forecasts with measurements was attempted. To investigate an unexpected behaviour of one ASC, hindcasts with wind effects and simulation with vortex feature extraction on a larger domain with more involved bathymetry were also partially carried out.Singapore-MIT Alliance for Research and TechnologySingapore. National Research Foundation (SMART/CENSAM initiative

СПОНТАННИЙ ПНЕВМОТОРАКС ПІД ЧАС ВАГІТНОСТІ. ОСНОВНІ АСПЕКТИ ДІАГНОСТИКИ, ТАКТИКИ ЛІКУВАННЯ ПНЕВМОТОРАКСУ І ВЕДЕННЯ ПОЛОГІВ

The aim of the study – to learn the features of diagnosis and treatment of pneumothorax during pregnancy and further delivery.Materials and Methods. The first-born women at the age of 32 years was on treatment and under supervision in Kyiv City Hospital number 7 and Kyiv Maternity Home number 7 from 30.03.11 to 20.10.11. She underwent a complete clinical diagnostic complex of examinations and treatment according to the current protocols.Results and Discussion. The article presents a review of the literature on spontaneous pneumothorax in pregnant women and describes a clinical case; overview of the features of diagnosis, treatment of pneumothorax during pregnancy and childbirth in these patients. An X-ray of a pregnant woman's chest is safe for the fetus after the 8th week of pregnancy. Modern minimally invasive methods of surgical treatment is the method of choice in the treatment of pneumothorax in pregnant women. Cesarean section is performed exclusively on obstetric indications. Comprehensive post-examination of the parturient child in the postpartum period is necessary to establish the etiology of pneumothorax, which was during pregnancy. Specific measures to prevent pneumothorax still do not exist.Conclusions. Pneumothorax during pregnancy is a rare phenomenon and occurs in 1 case per 10.000 births. Pneumothorax in pregnant women is a high threat to the life of the mother and fetus, determines the urgency of timely diagnosis and proper treatment of this disease. Diagnosis of intense pneumothorax should be carried out at the stage of clinical examination, and medical measures should be urgent and preceded by an X-ray examination.Цель исследования – изучить особенности диагностики и лечения пневмоторакса во время беременности и дальнейшего родоразрешения.Материалы и методы. Первобеременная в возрасте 32 года находилась на лечении и под наблюдением в КГКБ № 17 и 7-м роддоме г. Киева с 30.03.11 по 20.10.11. Ей проводили полный клинико-диагностический комплекс обследований и лечение соответственно действующим протоколам.Результаты исследования и их обсуждение. В статье представлен обзор литературы по вопросу спонтанного пневмоторакса у беременных и дано описание клинического случая. Обобщены особенности диагностики, лечения пневмоторакса во время беременности и ведения родов у таких больных. Рентгеновский снимок грудной клетки беременной является безопасным для плода после 8-й недели беременности. Современные мини-инвазивные методики хирургического лечения являются методом выбора при лечении пневмоторакса у беременных. Кесарево сечение выполняется исключительно по акушерским показаниям. Всестороннее дообследование роженицы в послеродовом периоде необходимо для установления этиологии пневмоторакса, который был во время беременности. Специфических мер профилактики пневмоторакса до сих пор не существует.Выводы. Пневмоторакс во время беременности – редкое явление и встречается в 1 случае на 10 000 родов. Пневмоторакс у беременных составляет высокую угрозу жизни матери и плода, обуславливает актуальность своевременной диагностики и правильного лечения этого заболевания. Диагностика напряженного пневмоторакса должна осуществляться на этапе клинического обследования, а лечебные мероприятия должны быть неотложными и предшествовать рентгенологическому обследованию.Мета дослідження – вивчити особливості діагностики та лікування пневмотораксу під час вагітності й подальшого розродження.Матеріали та методи. Першовагітна віком 32 роки перебувала на лікуванні та спостереженні в КМКЛ № 17 і 7-му пологовому будинку м. Києва з 30.03.11 до 20.10.11. Їй проводили повний клініко-діагностичний комплекс обстежень та лікування відповідно до діючих протоколів.Результати дослідження та їх обговорення. У статті представлено огляд літератури з питання спонтанного пневмотораксу у вагітних та подано опис клінічного випадку. Узагальнено особливості діагностики, лікування пневмотораксу під час вагітності та ведення пологів у таких хворих. Рентгенівський знімок грудної клітки вагітної є безпечним для плода після 8-го тижня вагітності. Сучасні міні-інвазивні методики хірургічного лікування є методом вибору при лікуванні пневмотораксу у вагітних. Кесарів розтин виконують виключно за акушерськими показаннями. Всебічне дообстеження породіллі в післяпологовому періоді необхідне для встановлення етіології пневмотораксу, який був під час вагітності. Специфічних заходів з профілактики пневмотораксу дотепер не існує.Висновки. Пневмоторакс під час вагітності – рідкісне явище і зустрічається в 1 випадку на 10 000 пологів. Пневмоторакс у вагітних становить високу загрозу життю матері та плода, що зумовлює актуальність своєчасної діагностики та правильного лікування цього захворювання. Діагностику напруженого пневмотораксу необхідно здійснювати на етапі клінічного обстеження, а лікувальні заходи повинні бути невідкладними та передувати рентгенологічному обстеженню

The Role of Wind Waves in Dynamics of the Air-Sea Interface

Wind waves are considered as an intermediate small-scale dynamic process at the air-sea interface,which modulates radically middle-scale dynamic processes of the boundary layers in water and air. It is shown that with the aim of a quantitative description of the impact said, one can use the numerical wind wave models which are added with the blocks of the dynamic atmosphere boundary layer (DABL) and the dynamic water upper layer (DWUL). A mathematical formalization for the problem of energy and momentum transfer from the wind to the upper ocean is given on the basis of the well known mathematical representations for mechanisms of a wind wave spectrum evolution. The problem is solved quantitatively by means of introducing special system parameters: the relative rate of the wave energy input, IRE, and the relative rate of the wave energy dissipation, DRE. For two simple wave-origin situations, the certain estimations for values of IRE and DRE are found, and the examples of calculating an impact of a wind sea on the characteristics of both the boundary layer of atmosphere and the water upper layer are given. The results obtained permit to state that the models of wind waves of the new (fifth) generation, which are added with the blocks of the DABL and the DWUL, could be an essential chain of the general model describing the ocean-atmosphere circulation.Comment: 11 pages, 4 figures, 1 tabl

Magnetohydrodynamics in stationary and axisymmetric spacetimes: A fully covariant approach

Minor modifications (text only); published version (28 pages)This work was supported by JSPS Grant-in-Aid for Scientific Research(C) under Grant No. 20540275, MEXT Grant-in-Aid for Scientific Research on Innovative Area under Grant No. 20105004, NSF Grant No. PHY100155, and ANR Grant No. 06-2-134423 Me´thodes mathe´matiques pour la relativite´ ge´ne´ral