Buoy System Research Articles

Development of Buoy System for Meteorology and Oceanographic Purposes

This research is part of the development of buoy system specially designed for meteorology and oceanographic purposes. The control system design and the brief operation of the buoy will be discussed in this paper.

Computational Methods of Average Wind Speed and Direction

Wind speed and wind direction are usually taken using two parameters: wind speed and wind direction. This paper studies the average wind speed and direction calculation methods. The paper first introduces to basic wind's knowledge, and then presents several methods in calculating average wind speed and direction. Lastly some graphs are plotted base on these computational methods and the implementation of these methods in an actual buoy system.

An alternative method for in-flight absolute radiometric calibration of thermal infrared channels of Chinese geostationary meteorological satellites

The aim of this study was to explore the feasibility of an alternative method for in-flight absolute radiometric calibration of the thermal infrared (TIR) channels of the Chinese meteorological satellites FengYun-2B (FY-2B) and FengYun-2C (FY-2C). The alternative method substituted radiosonde atmospheric profiles with those from the National Centers for Environmental Prediction (NCEP) reanalysis and the water surface brightness temperatures from TIR radiometers (CE312) with those from an automated hydrometeorological buoy (AHMB) system over Qinghai Lake (QHL), China. These data were then used to calculate the calibration coefficients and their uncertainty for the TIR channels of FY-2B and FY-2C. The at-sensor radiance (ASR) and at-sensor brightness temperature (ASBT) of the TIR channels of FY-2B and FY-2C were calculated by using 14 atmospheric profiles as measured by radiosonde over QHL in August 2003 and the corresponding NCEP reanalysis data, respectively. In addition, we conducted sensitivity tests to different atmospheric profiles of varying relative humidity and air temperatures on the ASR and ASBT of the TIR channels of FY-2B and FY-2C. Differences in gains between the regular and alternative methods are less than 0.005 mW m–2 sr−1 cm−1 DN−1. The sensitivity tests show that the ASR and ASBT are more sensitive to the relative humidity than the temperature in the atmospheric profile. Our results show that the proposed alternative method, of which the uncertainty is about 1.5 K for the TIR channels of FY-2B and FY-2C, is feasible for the TIR channels of various remote sensors. One of the major benefits of this alternative method is the potential for more frequent, reliable and inexpensive calibrations of the TIR sensors in operational conditions.

A Study of Forecasting the Seawater Temperature in Japanese Scallop Aquaculture Sea Area by Using Ubiquitous Buoy System

A Study of Forecasting the Seawater Temperature in Japanese Scallop Aquaculture Sea Area by Using Ubiquitous Buoy System

Precision Test of the Estimated Sea Surface Temperature by NOAA/AVHRR Data-Comparison with the Mutsu bay marine environment buoy system data-

Precision Test of the Estimated Sea Surface Temperature by NOAA/AVHRR Data-Comparison with the Mutsu bay marine environment buoy system data-

Management and research applications of real-time and archival passive acoustic sensors over varying temporal and spatial scales

Defining the appropriate scale over which to conduct a study in the marine environment is critical to achieving appropriate scientific, management, mitigation and conservation objectives. This paper focuses on applications of passive acoustic technologies over a range of spatial and temporal scales. It is divided into sections dealing with archival and real-time passive acoustic sensor applications. Each section assesses the principles behind using the respective technology and pro- vides recent examples of research and management applications for marine mammals and fish. The section on archival sensors highlights the need for continued development of automated acoustic detectors to assess large data sets. Case studies are presented of detectors developed for determining seasonal occurrence and distribution of haddock sounds and humpback whale vocalizations. Also presented are studies of other applications using archival sensors: tracking singing humpback whales in Brazil, using vocalizations to assess the reproductive strategies of Arctic bearded seals and assessing regional variability in call patterns for North Atlantic right whales. The section on real-time passive acoustic sensors focuses on real-time buoys and towed arrays. Case studies presented include a real-time buoy system used for monitoring endangered North Atlantic right whales and a station- ary autonomous array providing real-time access to Antarctic acoustic data. The value of using towed arrays for real-time applications is also assessed, and a case study is provided on the use of towed arrays to improve abundance estimates of North Pacific cetaceans and to better understand vocaliza- tion behaviors.

FROM NATURE, A PAST AND FUTURE

ON THE OPEN OCEAN, a small fishing boat bobs on the rolling waves. The team of scientists on board has set out from a remote atoll in Fiji, and they are out to find new chemistry in the inky Pacific depths. That takes some specialized tools, including a 6-foot-long metal probe with a precisely calibrated system of weights and small buoys, not to mention a lot of patience. Devised by William Fenical and a team of engineers at Scripps Institution of Oceanography, the probe is designed to plunge to the ocean floor, pick up a sediment sample, and then drop its weights and float back to the surface. Fenical has a variety of such devices, each with its own nickname—the “mud snapper,” for example, or the “mud missile.” Fenical’s coworker, microbiologist Paul Jensen, is aboard the boat, and he knows it can take nearly half an hour for the probe to descend to the bottom, ...

BASIC DESIGN OF JAPANESE NATIONWIDE GPS BUOY NETWORK WITH MULTI-PURPOSE OFFSHORE OBSERVATION SYSTEM

This paper introduces a basic design of GPS buoy multi-purpose data processing system using numerical filtering analysis. GPS buoy system and future plan of the GPS buoy network in Japan are introduced. Tsunami detection system with time series is considered. Directional wave analysis and offshore wind and current analysis methods are also investigated.

An autonomous, near-real-time buoy system for automatic detection of North Atlantic right whale calls.

A moored buoy system for automatic detection of endangered North Atlantic right whale (NARW) upcalls was developed to provide near-real-time information on the presence of whales. The marine components include the WHOI buoy platform (mooring, hydrophone, power system, surface expression, and antennae) and Cornell buoy electronics (housing, analog interface hardware, GPS, embedded computer, detection engine, and telemetry hardware). Shore-side Cornell components include telemetry equipment, server hardware and processing software, database, and interfaces for data annotation, access, and visualization. The buoy hardware/software system is capable of capturing and ranking NARW upcall candidates as 2 s, 2000 Hz sampled audio clips. GPS location, timestamp, and other metadata associated with each audio clip are bundled together and uploaded via satellite for processing. Human analysts regularly annotate incoming data, resulting in a curated database of NARW detections. Periodic “health and status” data allow for confirmation that buoys are functional. Regular voltage reporting helps predict required maintenance. Following initial implementations of the system in 2005, a series of successes and failures have led to system improvements. Deployments have progressed from prototype near-shore units to an operational network continuously monitoring the shipping lanes off Boston to meet ship strike mitigation requirements. Upcoming features and capabilities will be discussed.

Autonomous seafloor recorders and autodetection buoys to monitor whale activity for long-term and near-real-time applications.

Biologists and engineers from Cornell have installed arrays of autonomous seafloor recorders in multiple ocean habitats. These systems are designed to continuously monitor for the occurrence of endangered whales, particularly right whales; provide critical data on whale seasonal occurrence, distribution and relative numbers; and evaluate potential noise impacts from manmade activities and commercial shipping. Recent studies have been conducted in Massachusetts Bay around commercial LNG ports, the Arctic Ocean at seismic study locations, and in New York waters extending to the shelf edge. In combination with Cornell-developed MATLAB- and JAVA-based software applications, these seafloor recorders have been utilized to evaluate seasonal whale presence, calculate levels of commercial shipping and construction noise, and locate and track the movements and behaviors of individual whales under different acoustic conditions. Cornell and ocean engineers from the Woods Hole Oceanographic Institution have installed an operational network of autodetection buoys off New England to provide near-real-time data on right whale presence to transiting LNG vessels, government agencies, and public entities. When combined, the seafloor and autodetection buoy systems provide a powerful mechanism for understanding whale behavioral ecology and describing their acoustic habitats, while mitigating the risks from ship strike and noise exposure.

Onboard Real-Time Absolute Radiometric Calibration for Thermal Infrared Channels of Chinese Geostationary Meteorological Satellites

Abstract Forty-one cloud-free images of Qinghai Lake (QHL) in China and the corresponding digital numbers (DNs) of FengYun-2C (FY-2C) at 0000, 0600, 1200, and 1800 UTC from 1 July to 30 September 2005 are analyzed. The corresponding surface water temperatures of QHL measured by the automated hydrometeorological buoy (AHMB) system and the atmospheric profiles over QHL from the National Centers for Environmental Prediction (NCEP) reanalysis data are inputted into the atmospheric transfer model MODTRAN3.7 to calculate the entrance pupil radiance and brightness temperatures for thermal infrared (TIR) channels of FY-2C. Then, the absolute radiometric calibration coefficients of FY-2C, which are used to calculate the equivalent blackbody (EBB) temperatures TEBB, are calculated by comparing the entrance pupil radiance and brightness temperatures with the corresponding DNs. In addition, the temperatures of onboard blackbody (OBB) TOBB, primary, secondary, refraction, and calibration mirrors on the multichannel scanning radiometer (MSR) of FY-2C are detected remotely. Based on the linear correlation between TEBB − TOBB and temperatures of various mirrors, the transform equations from TOBB to TEBB are developed. Finally, the onboard real-time absolute radiometric calibration for TIR channels of geostationary meteorological satellite FY-2C is implemented with an uncertainty of about 1.5 and 2.1 K for TIR 1 and TIR 2 of FY-2C, respectively.

Spilled Oil Tracking Autonomous Buoy System

Spilled oil damages not only the ocean environment but also the regional economy. In order to minimize such damages we are now developing a spilled oil tracking autonomous buoy system. The buoys used in this system are expected to send their location, and the meteorological and oceanographic data around them, to the land base in real-time while they drift with spilled oil. In the case that the buoy detaches from the spilled oil by external forces, it must be capable of detecting and tracking the spilled oil autonomously. In this paper, we first describe the concept of this system. This is followed by the development of two kinds of oil-detecting sensors installed on the buoy: a contact sensor and a non-contact sensor. The efficiencies of these sensors were verified by carrying out various water tank experiments. The buoy tracks spilled oil with descending and ascending procedures by controlling its buoyancy and movable wings. The developed control algorithm was validated with some water tank experiments using a simple buoy model. Finally, we carried out field experiments, such as data measurements and autonomous tracking experiments, using a new buoy model equipped with oil detecting sensors, GPS and an anemometer. The results of field experiments show the efficiency of this system.

Development of a Virtual Buoy System using Real-time Wave Prediction

This study developed a real-time virtual buoy system using wave predictions produced by SWAN with input data of hourly analysis GPV. Although real-time ocean information is provided by NOWPHAS, the location of wave observations is limited. The present virtual buoy system fulfills a function of wave instrument by providing current and near future ocean conditions at any location where wave observations are unavailable. Archives of hourly wave analysis can be extracted at any location within the computational domain, allowing immediate evaluation of hindcasts. No additional simulations are needed to analyze incident events such as coastal disasters and accidents caused by high winds and waves.

Developing a Water Temperature Observation Network based on a Ubiquitous Buoy System to Support Aquacultures

The authors have been working on the support of the fishery industry using the information and communication technology. A water temperature observation network is proposed for supporting aquacultures, and a ubiquitous buoy system developed for this purpose is described. The ubiquitous buoy system was created by leveraging ubiquitous sensing technology with water temperature observation buoys that can be executed for $1,000, a figure designed to meet the demands of scallop cultivation fishermen. Since there are no base stations and gateways in marine environments, we selected mobile phones for the Internet connection to send the water temperature data by email. The ubiquitous buoys developed are light weight and of a compact design, and can be easily installed in marine fishery environments. Furthermore, the economic cost allows the buoys to be used in multiple point observation systems. Consequently, not only does the system allow water temperature observations in real time, but it can also be used in future applications to build water temperature observation networks using multiple ubiquitous buoys that share water temperature data and allow analysis of multipoint, multi-layer water temperature data, and thus facilitate efforts to visualize the makeup of water temperature distributions below the surface. Forty ubiquitous buoys have been placed in scallop cultivation regions along the coast of Hokkaido, and the water temperature data is starting to be used.

多目的ブイを用いた津波警報システムの人的被害軽減効果と要求性能に関する研究 ( 安全で快適な都市システムの実現をめざして(ICUS))

多目的ブイを用いた津波警報システムの人的被害軽減効果と要求性能に関する研究 ( 安全で快適な都市システムの実現をめざして(ICUS))

In situ observation of phytoplankton productivity by an underwater profiling buoy system: use of fast repetition rate fluorometry

To gain a better understanding of variability in phytoplankton productivity in the oceans, we developed an underwater profiling buoy system that uses a fast repetition rate (FRR) fluorometer. We used the profiling buoy system to observe phytoplankton productivity in Sagami Bay, Japan, from 15 April to 10 May 2005. During the observation period, chlorophyll a (chl a) con- centration increased gradually, peaking at > 5 mg chl a m -3 at a depth of 10 m, indicating the occur- rence of phytoplankton blooms. Gross oxygen production (PO2), as determined by FRR fluorometry, increased with the development of phytoplankton blooms and peaked at 49.4 mmol O2 m -2 h -1 on 2 May 2005, when both the chl a concentration and surface irradiance were high. To validate FRR- based PO2, the light-utilization efficiency of a water column (ψO2) was calculated and compared with previous values determined for this location by the oxygen evolution method. The ψO2 derived from FRR fluorometry showed good agreement with those by the oxygen evolution method, suggesting that FRR fluorometry was able to roughly estimate in situ daily PO2. Our profiling buoy system has potential benefits for the measurement of oceanic phytoplankton productivity at a high resolution.

八代海の潮流観測を目的とした漂流ブイの開発

Yatsushiro Sea is an enclosed water area, where the wave height is low and the tidal current is also quiet. Therefore, the seawater exchange with the open sea is not good. Furthermore, the driftage is running from Kumagawa River, and it drifts with the current of Yatushiro Sea. In this study, a drifting small buoy system equipped with a GPS receiver is used for the purpose of observing a tide of Yatsushiro Sea. The effect of current on the buoy was investigated experimentally and numerically, and it was developed the optimum shape of buoy.

Initial Assessment on Capability of Multi-Purpose Buoy System for Tsunami Warning

The authors assess the capability of multi-purpose buoy system for tsunami warning, by calculating the number of potential tsunami casualty. The method is developed by integration of tsunami numerical models and GIS analysis with population database and fragility functions. The present method is applied to the potential tsunami events along the Sunda megathrust to assess the effect of tsunami casualty mitigation by implementing international/regional tsunami observation network of multi-purpose buoy system. The results imply that the international tsunami observation network can contribute to reduce the tsunami casualty along the Indian Ocean countries up to 60% by expecting the lead time to issue the early warning.

제어봉에 의한 원형실린더 주위의 압력분포에 관한 수치해석

부표시스템 침수체의 주요형상인 실린더에 원형 제어봉을 부착하여 2차원 단면의 유동특성에 대해서 수치해석을 수행하였다. 유속을 0.1m/s에서 0.5m/s로 변화시키면서 부표시스템 주위의 유동현상을 파악하고, 부표시스템의 효과적인 유동제어를 위해 실린더 (D=50mm)에 제어봉의 직경을 0.1D 에서 0.5D까지 부착하여 조류에 의한 압력분포를 조사하였다. 유동장내의 속도분포는 PIV 계측기법 중 2프레림 입자추적 법을 사용하여 수치해석의 정도를 높이고자 0.3m/s에서 비교 평가하였다. 실린더 주위의 압력분포는 0.2D의 제어봉을 부착하였을 경우, 유속의 변화에 관계없이 가장 양호한 경향을 보이는 것을 알 수 있었다. The purpose in having a control rod on a buoy system is to control the motion of it. The system may be composed entirely of a single circular cylinder and a long mooring anchor cable. A control rod has one function to perform in meeting its purpose, and that is to develop a control force in consequence of its orientation and movement relative to the water. The forces and moments generated as a result of the effects of mutual interference. then determine the stability characteristics of the body. In this paper, the study of control-rod-attached buoy's 2-dimensional section was accomplished. model tests and numerical simulations had been carried out with different diameters of control rods. and varying the Reynolds number <TEX>$Re=5,000{\sim}25,000$</TEX> based on the cylinder diameter(D=50mm) to predict the performance of the body and the 2 frame particle tracking method Iud been used to obtain the velocity distribution in the flow field. 50mm circular cylinder Iud been used during the whole experiments and measured results had been compared with each other.

The M3A multi-sensor buoy network of the Mediterranean Sea

Abstract. A network of three multi-sensor timeseries stations able to deliver real time physical and biochemical observations of the upper thermocline has been developed for the needs of the Mediterranean Forecasting System during the MFSTEP project. They follow the experience of the prototype M3A system that was developed during the MFSPP project and has been tested during a pilot pre-operational period of 22 months (2000–2001). The systems integrate sensors for physical (temperature, salinity, turbidity, current speed and direction) as well as optical and chemical observations (dissolved oxygen, chlorophyll-a, PAR, nitrate). The south Aegean system (E1-M3A) follows a modular design using independent mooring lines and collects biochemical data in the upper 100 m and physical data in the upper 500 m of the water column. The south Adriatic buoy system (E2-M3A) uses similar instrumentation but on a single mooring line and also tests a new method of pumping water samples from relatively deep layers, performing analysis in the protected "dry" environment of the buoy interior. The Ligurian Sea system (W1-M3A) is an ideal platform for air-sea interaction processes since it hosts a large number of meteorological sensors while its ocean instrumentation, with real time transmission capabilities, is confined in the upper 50 m layer. Despite their different architecture, the three systems have common sampling strategy, quality control and data management procedures. The network operates in the Mediterranean Sea since autumn 2004 collecting timeseries data for calibration and validation of the forecasting system as well for process studies of regional dynamics.