Impact of the Rhône and Durance valleys on sea-breeze circulation in the Marseille area

Science.gov (United States)

Bastin, Sophie; Drobinski, Philippe; Dabas, Alain; Delville, Patricia; Reitebuch, Oliver; Werner, Christian

2005-03-01

Sea-breeze dynamics in the Marseille area, in the south of France, is investigated in the framework of the ESCOMPTE experiment conducted during summer 2001 in order to evaluate the role of thermal circulations on pollutant transport and ventilation. Under particular attention in this paper is the sea-breeze channelling by the broad Rhône valley and the narrow Durance valley, both oriented nearly-north-south, i.e., perpendicular to the coastline, and its possible impact on the sea-breeze penetration, intensity and depth, which are key information for air pollution issues. One situation of slight synoptic pressure gradient leading to a northerly flow in the Rhône valley (25 June 2001) and one situation of a weak onshore prevailing synoptic wind (26 June 2001) are compared. The impact of the Rhône and Durance valleys on the sea-breeze dynamics on these two typical days is generalized to the whole ESCOMPTE observing period. The present study shows by combining simple scaling analysis with wind data from meteorological surface stations and Doppler lidars that (i) the Durance valley always affects the sea breeze by accelerating the flow. A consequence is that the Durance valley contributes to weaken the temperature gradient along the valley and thus the sea-breeze circulation. In some cases, the acceleration of the channelled flow in the Durance valley suppresses the sea-breeze flow by temperature gradient inhibition; (ii) the Rhône valley does not generally affect the sea breeze significantly. However, if the sea breeze is combined with an onshore flow, it leads to further penetration inland and intensification of the low-level southerly flow. In this situation, lateral constriction may accelerate the sea breeze. Simple scaling analysis suggests that Saint Paul (44.35°N, about 100 km from the coastline) is the lower limit where sea breeze can be affected by the Rhône valley. These conclusions have implications in air quality topics as channelled sea breeze may

Analysis of Delayed Sea Breeze Onset for Fort Ord Prescribed Burning Operations

Science.gov (United States)

2015-12-01

DELAYED SEA BREEZE ONSET FOR FORT ORD PRESCRIBED BURNING OPERATIONS by Dustin D. Hocking December 2015 Thesis Advisor: Wendell Nuss Second...AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE ANALYSIS OF DELAYED SEA BREEZE ONSET FOR FORT ORD PRESCRIBED BURNING OPERATIONS 5...release; distribution is unlimited 12b. DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words) The U.S. Army conducts prescribed burns at Fort Ord

Modelling Local Sea-Breeze Flow and Associated Dispersion Patterns Over a Coastal Area in North-East Spain: A Case Study

Science.gov (United States)

Soler, M. R.; Arasa, R.; Merino, M.; Olid, M.; Ortega, S.

2011-07-01

The structure and evolution of the sea breeze in the north-west part of the Mediterranean (Catalonia, north-east Spain) is studied both experimentally and, predominantly, using numerical models to increase understanding of sea-breeze structure and three-dimensional (3D) pollution distributions in coastal environments. Sea-breeze components are modelled and analyzed using the fifth-generation Pennsylvania State University-National Centre for Atmospheric Research Mesoscale Model (MM5). The results show that the growth and structure of the sea-breeze circulation is modulated by the synoptic flow and especially by the complex topography of the area. 3D pollution transport in a sea breeze is modelled by coupling the MM5 to the Community Multiscale Air Quality (CMAQ) model, with results indicating that topography and synoptic flow are the main factors modulating horizontal and vertical pollutant transport in sea-breeze episodes. In this way, horizontal dispersion is limited by the complex topography of the area, whilst the sea-breeze flow is intensified by anabatic upslope winds that contribute to vertical pollutant transport. The numerical model results also indicate that the sea-breeze circulation with a weak return flow at upper levels grows due to a synoptic onshore wind component. However, such a sea-breeze circulation is capable of transporting pollutants towards the coast.

Nearshore Coastal Dynamics on a Sea-Breeze Dominated Micro-Tidal Beach (NCSAL)

Science.gov (United States)

Torres-Freyermuth, A.; Puleo, J. A.; Ruiz de Alegría-Arzaburu, A.; Figlus, J.; Mendoza, T.; Pintado-Patino, J. C.; Pieterse, A.; Chardon-Maldonado, P.; DiCosmo, N. R.; Wellman, N.; Garcia-Nava, H.; Palemón-Arcos, L.; Roberts, T.; López-González, J.; Bravo, M.; Ojeda, E.; Medellín, G.; Appendini, C. M.; Figueroa, B.; González-Leija, M.; Enriquez, C.; Pedrozo-Acuña, A.; Salles, P.

2014-12-01

A comprehensive field experiment devoted to the study of coastal processes on a micro-tidal beach was conducted from March 30th to April 12th 2014 in Sisal, Yucatán México. Wave conditions in the study area are controlled by local (i.e., sea-breezes) and meso-scale (i.e., Nortes) meteorological events. Simultaneous measurements of waves, tides, winds, currents, sediment transport, runup, and beach morphology were obtained in this experiment. Very dense nearshore instrumentation arrays allow us the study of the cross-/along- shore variability of surf/swash zone dynamics during different forcing conditions. Strong sea-breeze wind events produced a diurnal cycle with a maximum wind speed of 14 m/s. The persistent sea-breeze system forces small-amplitude (Hs1 m) Norte event, lasting 48 hours, reached the coast on April 8th generating a long-period swell (Tp>10 s) arriving from the NNW. This event induced an eastward net sediment transport across a wide surf zone. However, long-term observations of sand impoundment at a groin located near the study area suggests that the net sediment transport in the northern Yucatan peninsula is controlled by sea-breeze events and hence swash zone dynamics play an important role in the net sediment budget of this region. A comparative study of surf and swash zone dynamics during both sea-breeze and Norte events will be presented. The Institute of Engineering of UNAM, throughout an International Collaborative Project with the University of Delaware, and CONACYT (CB-167692) provided financial support. The first author acknowledges ONR Global for providing financial support throughout the Visiting Scientist Program.

Numerical simulation of sea breeze characteristics observed at ...

Indian Academy of Sciences (India)

R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

observed values except during night time wherein a small difference is seen in the wind speed. 1. Introduction .... opposing the sea breeze on the chosen day. So, the study is .... 3.3 TIBL height. The formation and growth of Thermal Internal.

A characterisation of sea-breeze events in the eastern Cantabrian coast (Spain) from observational data and WRF simulations

Science.gov (United States)

Arrillaga, Jon A.; Yagüe, Carlos; Sastre, Mariano; Román-Cascón, Carlos

2016-11-01

The behaviour of the sea breeze along the north coast of Spain is investigated using observations of two topographically contrasting sites together with simulations from the Weather Research and Forecasting (WRF) model. An objective and systematic selection method is used to detect sea-breeze days from a database of two summer months. The direction and intensity of the sea breeze are significantly affected by the topography of the area; indeed, the estimated sea-breeze intensity shows an opposite relationship with the cross-shore temperature gradient for both sites. WRF simulations reproduce the onset of the sea breeze, but some characteristics are not adequately simulated: they generally overestimate the wind speed, smooth the temperature evolution and they do not represent the correct interaction with the terrain-induced flows. Additionally, four sensitivity experiments are performed with the WRF model varying the Planetary Boundary Layer (PBL) scheme, as well as the grid analysis nudging for an anomalous case study which is incorrectly filtered. As the two simulations considering nudging reproduce an unreal (not observed) sea breeze, this day turns out to be of great interest: it allows to evaluate the influence of the passage of the sea-breeze front (SBF) in other variables mainly related to turbulence. Furthermore, the best model scores are obtained for the PBL scheme that does not use a TKE closure.

Impact of sea breeze on wind-seas off Goa, west coast of India

Indian Academy of Sciences (India)

during November–May, winds in the coastal regions of India are dominated by sea breeze. It has an impact on the daily cycle of the sea state near the coast. The impact is quite significant when large scale winds are weak. During one such event, 1–15 April 1997, a Datawell directional waverider buoy was deployed in 23m ...

Field Observations of Swash-Zone Dynamics on a Sea-Breeze Dominated Beach at the Yucatán Peninsula, México

Science.gov (United States)

Chardon-Maldonado, P.; Puleo, J. A.; Torres-Freyermuth, A.

2016-02-01

Sea breezes can modify the nearshore processes and alter beach morphology depending on the geographical location. Prior studies have shown that surf zone wave energy intensifies during strong sea-breeze conditions (wind speeds > 10 ms-1) and the impact on the coast can be similar to a small storm. However, few research efforts have investigated the coastal dynamics on sea-breeze dominated beaches (e.g., Masselink and Pattiaratchi, 1998, Mar. Geol.; Pattiaratchi et al., 1997, Cont. Shelf Res.) and, to the authors' knowledge, only one study has focused on swash-zone processes (Sonu et al., 1973, EOS). A field study was performed on a microtidal, low wave energy, sea-breeze dominated sandy beach in order to investigate the effects of local (sea breeze) and synoptic (storm) scale meteorological events on swash-zone dynamics. In-situ measurements of swash-zone hydrodynamics and sediment transport processes were collected from March 31st to April 12th, 2014 in Sisal, Yucatán located on the northern coast of the Yucatán Peninsula. Flow velocities and suspended sediment concentrations were measured concurrently, at multiple cross-shore and alongshore locations, using Vectrino-II profiling velocimeters and optical backscatter sensors, respectively. The high resolution data allowed the quantification of bed shear stress, turbulent dissipation rate, sediment loads and sediment flux during a mesoscale frontal system (cold-front passage referred to as an El Norte) and local sea-breeze cycles. Field observations showed that strong swash-zone bed shear stresses, turbulence intensity and sediment suspension occur during energetic conditions (i.e., El Norte event). On the other hand, despite milder energy conditions during the sea-breeze events, the alongshore component of bed-shear stresses and velocities can be significant owing to the high incidence wave angle associated with the sea-breeze system in the study area. The increased forcing in the swash zone induced sediment

Effect of sea breeze circulation on aerosol mixing state and radiative properties in a desert setting

Directory of Open Access Journals (Sweden)

Y. Derimian

2017-09-01

Full Text Available Chemical composition, microphysical, and optical properties of atmospheric aerosol deep inland in the Negev Desert of Israel are found to be influenced by daily occurrences of sea breeze flow from the Mediterranean Sea. Abrupt increases in aerosol volume concentration and shifts of size distributions towards larger sizes, which are associated with increase in wind speed and atmospheric water content, were systematically recorded during the summertime at a distance of at least 80 km from the coast. Chemical imaging of aerosol samples showed an increased contribution of highly hygroscopic particles during the intrusion of the sea breeze. Besides a significant fraction of marine aerosols, the amount of internally mixed marine and mineral dust particles was also increased during the sea breeze period. The number fraction of marine and internally mixed particles during the sea breeze reached up to 88 % in the PM1–2. 5 and up to 62 % in the PM2. 5–10 size range. Additionally, numerous particles with residuals of liquid coating were observed by SEM/EDX analysis. Ca-rich dust particles that had reacted with anthropogenic nitrates were evidenced by Raman microspectroscopy. The resulting hygroscopic particles can deliquesce at very low relative humidity. Our observations suggest that aerosol hygroscopic growth in the Negev Desert is induced by the daily sea breeze arrival. The varying aerosol microphysical and optical characteristics perturb the solar and thermal infrared radiations. The changes in aerosol properties induced by the sea breeze, relative to the background situation, doubled the shortwave radiative cooling at the surface (from −10 to −20.5 W m−2 and increased by almost 3 times the warming of the atmosphere (from 5 to 14 W m−2, as evaluated for a case study. Given the important value of observed liquid coating of particles, we also examined the possible influence of the particle homogeneity assumption on the

Urban effects of Chennai on sea breeze induced convection and ...

Indian Academy of Sciences (India)

gate the influence of Chennai urban land use on sea breeze initiated convection and precipitation. ... The larger surface temperature gradient along the coast due to urban effects increased onshore flow by 4.0m s. −1 ... Observational and modeling studies show the .... Explicit equations for cloud water, rainwater, ice.

Mesoscale model response to random, surface-based perturbations — A sea-breeze experiment

Science.gov (United States)

Garratt, J. R.; Pielke, R. A.; Miller, W. F.; Lee, T. J.

1990-09-01

The introduction into a mesoscale model of random (in space) variations in roughness length, or random (in space and time) surface perturbations of temperature and friction velocity, produces a measurable, but barely significant, response in the simulated flow dynamics of the lower atmosphere. The perturbations are an attempt to include the effects of sub-grid variability into the ensemble-mean parameterization schemes used in many numerical models. Their magnitude is set in our experiments by appeal to real-world observations of the spatial variations in roughness length and daytime surface temperature over the land on horizontal scales of one to several tens of kilometers. With sea-breeze simulations, comparisons of a number of realizations forced by roughness-length and surface-temperature perturbations with the standard simulation reveal no significant change in ensemble mean statistics, and only small changes in the sea-breeze vertical velocity. Changes in the updraft velocity for individual runs, of up to several cms-1 (compared to a mean of 14 cms-1), are directly the result of prefrontal temperature changes of 0.1 to 0.2K, produced by the random surface forcing. The correlation and magnitude of the changes are entirely consistent with a gravity-current interpretation of the sea breeze.

A climatological study of sea breeze clouds in the southeast of the Iberian Peninsula (Alicante, Spain)

Energy Technology Data Exchange (ETDEWEB)

Azorin-Molina, C. [Grupo de Climatologia, Universidad de Barcelona, Barcelona, Cataluna (Spain)]. E-mail: cazorin@ceam.es; Sanchez-Lorenzo, A. [Grupo de Climatologia, Universidad de Barcelona, Barcelona, Cataluna (Spain); Calbo, J. [Grupo de Fisica Ambiental, Universidad de Girona, Campus Montilivi, Cataluna (Spain)

2009-01-15

Sea breezes blow under anticyclonic weather types, weak surface pressure gradients, intense solar radiation and relatively cloud-free skies. Generally, total cloud cover must be less than 4/8 in order to cause a thermal and pressure difference between land and sea air which allows the development of this local wind circulation. However, many numerical and observational studies have analyzed the ability of sea breezes to generate clouds in the convective internal boundary layer and in the sea breeze convergence zone. Accordingly, the aim of this study is to statistically analyze the impact of sea breezes on cloud types in the convective internal boundary layer and in the sea breeze convergence zone. The study area is located in the southeast of the Iberian Peninsula (province of Alicante, Spain) and the survey corresponds to a 6-yr study period (2000-2005). This climatological study is mainly based on surface cloud observations at the Alicante-Ciudad Jardin station (central coastal plain) and on an extensive cloud observation field campaign at the Villena-Ciudad station (Prebetic mountain ranges) over a 3-yr study period (2003-2005). The results confirm the hypothesis that the effect of sea breezes on cloud genera is to increase the frequency of low (Stratus) and convective (Cumulus) clouds. Sea breezes trigger the formation of thunderstorm clouds (Cumulonimbus) at the sea breeze convergence zone, which also have a secondary impact on high-level (Cirrus, Cirrocumulus, Cirrostratus), medium-level (Altostratus, Altocumulus) and low-level clouds (Stratus, Stratocumulus, Nimbostratus) associated with the Cumulonimbus clouds (e.g., Cumulonimbus anvil). [Spanish] Las brisas marinas soplan bajo tipos de tiempo anticiclonicos, debiles gradientes de presion atmosferica, radiacion solar intensa y cielos practicamente despejados. Por lo general, la cobertura nubosa total debe ser inferior a 4/8 para que se genere un diferencial termico y de presion entre el aire sobre las

The influence of sea- and land-breeze circulations on the diurnal variability in precipitation over a tropical island

Directory of Open Access Journals (Sweden)

L. Zhu

2017-11-01

Full Text Available This study examines the diurnal variation in precipitation over Hainan Island in the South China Sea using gauge observations from 1951 to 2012 and Climate Prediction Center MORPHing technique (CMORPH satellite estimates from 2006 to 2015, as well as numerical simulations. The simulations are the first to use climatological mean initial and lateral boundary conditions to study the dynamic and thermodynamic processes (and the impacts of land–sea breeze circulations that control the rainfall distribution and climatology. Precipitation is most significant from April to October and exhibits a strong diurnal cycle resulting from land–sea breeze circulations. More than 60 % of the total annual precipitation over the island is attributable to the diurnal cycle with a significant monthly variability. The CMORPH and gauge datasets agree well, except that the CMORPH data underestimate precipitation and have a 1 h peak delay. The diurnal cycle of the rainfall and the related land–sea breeze circulations during May and June were well captured by convection-permitting numerical simulations with the Weather Research and Forecasting (WRF model, which were initiated from a 10-year average ERA-Interim reanalysis. The simulations have a slight overestimation of rainfall amounts and a 1 h delay in peak rainfall time. The diurnal cycle of precipitation is driven by the occurrence of moist convection around noontime owing to low-level convergence associated with the sea-breeze circulations. The precipitation intensifies rapidly thereafter and peaks in the afternoon with the collisions of sea-breeze fronts from different sides of the island. Cold pools of the convective storms contribute to the inland propagation of the sea breeze. Generally, precipitation dissipates quickly in the evening due to the cooling and stabilization of the lower troposphere and decrease of boundary layer moisture. Interestingly, the rather high island orography is not a

Identification of the Sea-Land Breeze Event and Influence to the Convective Activities on the Coast of Deli Serdang

Science.gov (United States)

Saragih, I. J. A.; Putra, A. W.; Nugraheni, I. R.; Rinaldy, N.; Yonas, B. W.

2017-12-01

Located close to the sea indicates that there are influences of the sea-land breeze circulation on the weather condition in Deli Serdang. The purpose of this study is to simulate sea-land breeze occurrence and its influence on the convective activities in Deli Serdang. The research area covers the area of Deli Serdang Regency and the surrounding ocean region in the coordinates 02°57‧-03°16‧N & 98°33‧-99°27‧E where Kualanamu Meteorological Station is the centre of the research area at coordinate 03°34‧N & 98°44‧E and the elevation about 27MAMSL. The research time is a day with the highest rainfall in the highest peak rainy month. The raw data consist of the Himawari-8 satellite image from BMKG, FNL (Final Analysis) data from http://rda.ucar.edu, and meteorological observation data from Kualanamu Meteorology Station. This study indicates that WRF-ARW can simulate the sea-land breeze occurrence on the coast of Deli Serdang well. The existence of the convective index cover in the convergence area proves the sea-land breeze occurred in the coast of Deli Serdang can form the convergence area as the interacted result with the wind from other directions that support convective activities.

A numerical study of sea breeze circulation observed at a tropical ...

Indian Academy of Sciences (India)

and roughness occur in the air adjacent to the coast and lead to formation of a thermal inter- nal boundary layer (TIBL) (Stull 1988). This effec- tively reduces the mixing height in the coastal regions in the daytime. Land–sea breeze circula- tion and TIBL are the two important phenomena that influence the pollution plume ...

Evaluation of the atmospheric model WRF on the Qatar peninsula for a converging sea-breeze event

Science.gov (United States)

Balan Sobhana, Sandeepan; Nayak, Sashikant; Panchang, Vijay

2016-04-01

Qatar, a narrow peninsula covering an area of 11437 sq km, extends northwards into the Arabian Gulf for about 160km and has a maximum width of 88km. The convex shape of the coast-line and narrowness of the peninsula results in the Qatar region experiencing complex wind patterns. The geometry is favorable for formation of the land-sea breeze from both coastal sides of the peninsula. This can lead to the development of sea breeze convergence zones in the middle of the country. Although circulations arising from diurnal thermal contrast of land and water are amongst most intensively studied meteorological phenomena, there is no reported study for the Qatar peninsula and very few studies are reported for the Arabian Gulf region as whole. It is necessary to characterize the wind field for applications such as assessing air pollution, renewable energy etc. A non-hydrostatic mesoscale model, Weather Research and Forecast (WRF) with a nested high resolution grid permits the investigation of such fine scale phenomena. Data from eighteen land based Automated Weather Stations (AWS) and two offshore buoys deployed and maintained by the Qatar Meteorological Department were analyzed. Based on the analysis a clear case of sea breeze convergence were seen on 18 September 2015. Model simulations were used to investigate the synoptic conditions associated with the formation of this event. The season is characterized by week ambient north westerly wind over the Arabian Gulf. The WRF model performance is validated using observed in-situ data. Model simulations show that vertical extent of sea breeze cell was up to 1 km and the converging sea breeze regions were characterized with high vertical velocities. The WRF simulation also revealed that with high resolution, the model is capable of reproducing the fine scale patterns accurately. The error of predictions in the inner domain (highest resolution) are found to be relatively lower than coarse resolution domain. The maximum wind speed

Nearshore circulation on a sea breeze dominated beach during intense wind events

Science.gov (United States)

Torres-Freyermuth, Alec; Puleo, Jack A.; DiCosmo, Nick; Allende-Arandía, Ma. Eugenia; Chardón-Maldonado, Patricia; López, José; Figueroa-Espinoza, Bernardo; de Alegria-Arzaburu, Amaia Ruiz; Figlus, Jens; Roberts Briggs, Tiffany M.; de la Roza, Jacobo; Candela, Julio

2017-12-01

A field experiment was conducted on the northern Yucatan coast from April 1 to April 12, 2014 to investigate the role of intense wind events on coastal circulation from the inner shelf to the swash zone. The study area is characterized by a micro-tidal environment, low-energy wave conditions, and a wide and shallow continental shelf. Furthermore, easterly trade winds, local breezes, and synoptic-scale events, associated with the passage of cold-fronts known as Nortes, are ubiquitous in this region. Currents were measured concurrently at different cross-shore locations during both local and synoptic-scale intense wind events to investigate the influence of different forcing mechanisms (i.e., large-scale currents, winds, tides, and waves) on the nearshore circulation. Field observations revealed that nearshore circulation across the shelf is predominantly alongshore-directed (westward) during intense winds. However, the mechanisms responsible for driving instantaneous spatial and temporal current variability depend on the weather conditions and the across-shelf location. During local strong sea breeze events (W > 10 m s-1 from the NE) occurring during spring tide, westward circulation is controlled by the tides, wind, and waves at the inner-shelf, shallow waters, and inside the surf/swash zone, respectively. The nearshore circulation is relaxed during intense land breeze events (W ≈ 9 m s-1 from the SE) associated with the low atmospheric pressure system that preceded a Norte event. During the Norte event (Wmax≈ 15 m s-1 from the NNW), westward circulation dominated outside the surf zone and was correlated to the Yucatan Current, whereas wave breaking forces eastward currents inside the surf/swash zone. The latter finding implies the existence of large alongshore velocity shear at the offshore edge of the surf zone during the Norte event, which enhances mixing between the surf zone and the inner shelf. These findings suggest that both sea breezes and Nortes play

Vertical Structure of the Urban Boundary Layer over Marseille Under Sea-Breeze Conditions

Science.gov (United States)

Lemonsu, Aude; Bastin, Sophie; Masson, Valéry; Drobinski, Philippe

2006-03-01

During the UBL-ESCOMPTE program (June July 2001), intensive observations were performed in Marseille (France). In particular, a Doppler lidar, located in the north of the city, provided radial velocity measurements on a 6-km radius area in the lowest 3 km of the troposphere. Thus, it is well adapted to document the vertical structure of the atmosphere above complex terrain, notably in Marseille, which is bordered by the Mediterranean sea and framed by numerous massifs. The present study focuses on the last day of the intensive observation period 2 (26 June 2001), which is characterized by a weak synoptic pressure gradient favouring the development of thermal circulations. Under such conditions, a complex stratification of the atmosphere is observed. Three-dimensional numerical simulations, with the Méso-NH atmospheric model including the town energy balance (TEB) urban parameterization, are conducted over south-eastern France. A complete evaluation of the model outputs was already performed at both regional and city scales. Here, the 250-m resolution outputs describing the vertical structure of the atmosphere above the Marseille area are compared to the Doppler lidar data, for which the spatial resolution is comparable. This joint analysis underscores the consistency between the atmospheric boundary layer (ABL) observed by the Doppler lidar and that modelled by Méso-NH. The observations and simulations reveal the presence of a shallow sea breeze (SSB) superimposed on a deep sea breeze (DSB) above Marseille during daytime. Because of the step-like shape of the Marseille coastline, the SSB is organized in two branches of different directions, which converge above the city centre. The analysis of the 250-m wind fields shows evidence of the role of the local topography on the local dynamics. Indeed, the topography tends to reinforce the SSB while it weakens the DSB. The ABL is directly affected by the different sea-breeze circulations, while the urban effects appear

On the use of GPS tomography to investigate water vapor variability during a Mistral/sea breeze event in southeastern France

Science.gov (United States)

Bastin, Sophie; Champollion, Cédric; Bock, Olivier; Drobinski, Philippe; Masson, Frédéric

2005-03-01

Global Positioning System (GPS) tomography analyses of water vapor, complemented by high-resolution numerical simulations are used to investigate a Mistral/sea breeze event in the region of Marseille, France, during the ESCOMPTE experiment. This is the first time GPS tomography has been used to validate the three-dimensional water vapor concentration from numerical simulation, and to analyze a small-scale meteorological event. The high spatial and temporal resolution of GPS analyses provides a unique insight into the evolution of the vertical and horizontal distribution of water vapor during the Mistral/sea-breeze transition.

Short range forecasting of sea breeze generated thunderstorms at the Kennedy Space Center: A real-time experiment using a primitive equation mesoscale numerical model

Science.gov (United States)

Lyons, Walter A.; Schuh, Jerome A.; Moon, Dennis; Pielke, Roger A.; Cotton, William; Arritt, Raymond

1987-01-01

The operational efficiency of using guidance from a mesoscale numerical model to improve sea breeze thunderstorm forecasts at and around the Shuttle landing strip was assessed. The Prognostic Three-Dimensional Mesoscale (P3DM) model, developed as a sea breeze model, reveals a strong correlation between regions of mesoscale convergence and the triggering of sea breeze convection thunderstorms. The P3DM was modified to generate stability parameters familiar to the operational forecaster. In addition to the mesoscale fields of wind, vertical motion, moisture, temperature, a stability indicator, a combination of model-predicted K and Lifted Indices and the maximum grid cell vertical motion, were proposed and tested. Results of blind tests indicate that a forecaster, provided with guidance derived from model output, could improve local thunderstorm forecasts.

Numerical analysis of air pollution in a combined field of land/sea breeze and mountain/valley wind

International Nuclear Information System (INIS)

Kitada, T.; Igarashi, K.; Owada, M.

1986-01-01

Air pollution in the presence of two types of local flows (i.e., land/sea breeze and mountain/valley wind) was studies by advection simulation of the cluster of hypothetical fluid particles, and transport/chemistry calculation employing a three-dimensional Eulerian model for 20 advected species and about 90 chemical reactions. Three-dimensional flow fields over the River Yahagi basin in Japan were estimated for 48 h using an objective method with routine wind observations. Those obtained showed characteristics of the combined local flows such that in the daytime sea breeze and valley wind tend to form one united flow with substantial wind velocity in the whole region and, in contrast, land breeze and mountain wind during the nighttime form two separated circulating flows with a clear weak-wind area between the two local flow regimes. The results of the advection simulation of fluid particles and the transport/chemistry calculation using those flows as inputs elucidated how the features found in the diurnally varying, complex local flows contribute to produce characteristic time-variations of the concentrations of both primary and secondary pollutants. Among others, dynamics of NO 2 , HNO 3 , PAN, O 3 , SO 2 , and SO 4 /sup =/ concentrations are discussed

Atmospheric diffusion at coastal site in presence of sea-breeze

International Nuclear Information System (INIS)

Messaci, M.

1987-03-01

The coastal sites present special features so much by the dominant wind system then by the lower layers of the atmosphere. Two types of experiments were handled on a coastal site in presence of sea breeze. First, vertical atmospheric sounding by radiosounding and by throwing experimental balloons; then the discharge of tracer: the SF6. The first experiment lead us to put in a prominent position the Internal Boundary Layer and the determination of its height. Whereas the second experiment allowed us to estimate the diffusion parameters of the site as well as to obtain interesting conclusions on diffusivity of the environment studied and the influence of certain factors

When land breezes collide: Converging diurnal winds over small bodies of water

OpenAIRE

Gille, ST; Llewellyn Smith, SG

2014-01-01

© 2013 Royal Meteorological Society. Over enclosed and semi-enclosed bodies of water, the land-breeze/sea-breeze circulation is expected to be modified by the presence of opposing coastlines. These effects are studied using satellite scatterometer surface wind observations from the QuikSCAT and ADEOS-2 tandem mission from April-October 2003. Winds are studied for six bodies of water: the Red Sea, the Gulf of California, the Mediterranean, the Adriatic Sea, the Black Sea and the Caspian Sea. T...

The influence of the summer sea breeze on thermal comfort in Funchal (Madeira). A contribution to tourism and urban planning.

Energy Technology Data Exchange (ETDEWEB)

Lopes, Antonio; Lopes, Sergio; Joao Alcoforado, Maria [Univ. de Lisboa (Portugal). Centro der Estudos Geograficos; Matzarakis, Andreas [Freiburg Univ. (Germany). Meteorological Inst.

2011-10-15

Tourism plays a crucial role for the development of coastal areas. Despite the mildness of Madeira's climate, very hot days can occur during summer, a situation to which most tourists from northern Europe (the majority of foreign tourists) are poorly adapted. As sea breezes strongly contribute to moderate heat stress in urban environments, their influence on the thermal comfort on the island has been studied. Sea breezes occurred on 84 % of the days during the period under study (May to October 2006). They usually start around 09:30 h and end after 22:00 h, with an average duration of about 12:50 hours and a mean velocity of 2.9 m/s. Physiologically Equivalent Temperature (PET) was used to evaluate the thermal comfort of a sample of days during the summer of 2006. It was concluded that most of the sites in the city are ''slightly comfortable'' during normal days with sea breeze, but only shore sites and the highest green areas offer some comfort during hot days. Inside the city, the thermal perception is generally ''hot'' and strong heat stress can occur. As sea breezes are important to mitigate heat stress, some basic guidelines were presented: urban planners should take advantage of this wind system avoiding dense construction near the shoreline that would act as a barrier to the renewal of the air inside the city. In terms of tourism, planners and local authorities should provide solutions to mitigate the negative effects during hot periods, creating a system to warn and relocate more vulnerable tourists to places near the shore line, to the mountains, to gardens and air-conditioned buildings. In combination with other components (beauty of the island, gastronomy, cultural values and safety), climate information can be a factor of attractiveness to tourists. (orig.)

Observed and simulated sea breeze characteristics over Rayong coastal area, Thailand

Science.gov (United States)

Phan, Tung Thanh; Manomaiphiboon, Kasemsan

2012-05-01

This work presents the detailed characterization of sea breeze (SB) over the Rayong coastal area, one of the most rapidly developed and highly industrialized areas during the last decade in Thailand, using observation data analysis and fine-resolution (2 km) mesoscale meteorological modeling with incorporation of new land cover and satellite-derived vegetation fraction data sets. The key characteristics considered include frequency of SB occurrence, sea-breeze day (SBD) identification, degree of inland penetration, and boundary layer development. It was found that SBs occur frequently in the winter due mainly to relatively large land-sea temperature contrasts and minimally in the wet season. Monthly mean SB onset and cessation times are at around 12-15 local time (LT) and 18-21 LT, respectively, and its strength peaks during the early- to mid-afternoon. Monthly SB hodographs generally exhibit clockwise rotations, and SB inland penetration (at PCD-T tower) ranges widely with the monthly means of 25-55 km from the coast. Mesoscale MM5 modeling was performed on two selected SBDs (13 January and 16 March 2006), on which the SBs are under weak and onshore strong influences from background winds, respectively. Simulated near-surface winds and temperature were found to be in fair-to-acceptable agreement with the observations. The SB circulation along the Rayong coast is clearly defined with a return flow aloft and a front on 13 January, while it is enhanced by the onshore background winds on 16 March. Another SB along the Chonburi coast also develops separately, but their fronts merge into one in the mid-afternoon, resulting in large area coverage by the SB. Simulated planetary boundary layer height over the land area is significantly affected by a thermal internal boundary layer (TIBL) induced by an SB, which is found to be low near the coast and increases toward the front (up to 800-1,000 m along the Rayong coast).

Modeling mesoscale diffusion and transport processes for releases within coastal zones during land/sea breezes

International Nuclear Information System (INIS)

Lyons, W.A.; Keen, C.S.; Schuh, J.A.

1983-12-01

This document discusses the impacts of coastal mesoscale regimes (CMRs) upon the transport and diffusion of potential accidental radionuclide releases from a shoreline nuclear power plant. CMRs exhibit significant spatial (horizontal and vertical) and temporal variability. Case studies illustrate land breezes, sea/lake breeze inflows and return flows, thermal internal boundary layers, fumigation, plume trapping, coastal convergence zones, thunderstorms and snow squalls. The direct application of a conventional Gaussian straight-line dose assessment model, initialized only by on-site tower data, can potentially produce highly misleading guidance as to plume impact locations. Since much is known concerning CMRs, there are many potential improvements to modularized dose assessment codes, such as by proper parameterization of TIBLs, forecasting the inland penetration of convergence zones, etc. A three-dimensional primitive equation prognostic model showed excellent agreement with detailed lake breeze field measurements, giving indications that such codes can be used in both diagnostic and prognostic studies. The use of relatively inexpensive supplemental meteorological data especially from remote sensing systems (Doppler sodar, radar, lightning strike tracking) and computerized data bases should save significantly on software development costs. Better quality assurance of emergency response codes could include systems of flags providing personnel with confidence levels as to the applicability of a code being used during any given CMR

Interaction between turbulent flow and sea breeze front over urban-like coast in large-eddy simulation

Science.gov (United States)

Jiang, Ping; Wen, Zhiping; Sha, Weiming; Chen, Guixing

2017-05-01

Turbulent flow and its interaction with a sea breeze front (SBF) over an urban-like coast with a regular block array were investigated using a building-resolving computational fluid dynamics model. It was found that during daytime with an offshore ambient flow, streaky turbulent structures tended to grow within the convective boundary layer (CBL) over a warm urban surface ahead of the SBF. The structures were organized as streamwise streaks at an interval of a few hundred meters, which initiated at the rooftop level with strong wind shear and strengthens in the CBL with moderate buoyancy. The streaks then interacted with the onshore-propagating SBF as it made landfall. The SBF, which was initially characterized as a shallow and quasi-linear feature over the sea, developed three-dimensional structures with intensified updrafts at an elevated frontal head after landfall. Frontal updrafts were locally enhanced at intersections where the streaks merged with the SBF, which greatly increased turbulent fluxes at the front. The frontal line was irregular because of merging, tilting, and transformation effects of vorticity associated with streaky structures. Inland penetration of the SBF was slowed by the frictional effect of urban-like surfaces and turbulent flow on land. The overall SBF intensity weakened after the interaction with turbulent flow. These findings aid understanding of local weather over coastal cities during typical sea breeze conditions.

The monsoon system: Land-sea breeze or the ITCZ?

Science.gov (United States)

Gadgil, Sulochana

2018-02-01

For well over 300 years, the monsoon has been considered to be a gigantic land-sea breeze driven by the land-ocean contrast in surface temperature. In this paper, this hypothesis and its implications for the variability of the monsoon are discussed and it is shown that the observations of monsoon variability do not support this popular theory of the monsoon. An alternative hypothesis (whose origins can be traced to Blanford's (1886) remarkably perceptive analysis) in which the basic system responsible for the Indian summer monsoon is considered to be the Intertropical Convergence Zone (ITCZ) or the equatorial trough, is then examined and shown to be consistent with the observations. The implications of considering the monsoon as a manifestation of the seasonal migration of the ITCZ for the variability of the Indian summer monsoon and for identification of the monsoonal regions of the world are briefly discussed.

Utilizing TRMM to Analyze Sea Breeze Thunderstorm Patterns During El Nino Southern Oscillations and Their Effects upon Available Fresh Water for South Florida Agricultural Planning and Management

Science.gov (United States)

Cooley, Clayton; Billiot, Amanda; Lee, Lucas; McKee, Jake

2010-01-01

Water is in high demand for farmers regardless of where you go. Unfortunately, farmers in southern Florida have fewer options for water supplies than public users and are often limited to using available supplies from surface and ground water sources which depend in part upon variable weather patterns. There is an interest by the agricultural community about the effect weather has on usable surface water, however, research into viable weather patterns during La Nina and El Nino has yet to be researched. Using rainfall accumulation data from NASA Tropical Rainfall Measurement Mission (TRMM) satellite, this project s purpose was to assess the influence of El Nino and La Nina Oscillations on sea breeze thunderstorm patterns, as well as general rainfall patterns during the summer season in South Florida. Through this research we were able to illustrate the spatial and temporal variations in rainfall accumulation for each oscillation in relation to major agricultural areas. The study period for this project is from 1998, when TRMM was first launched, to 2009. Since sea breezes in Florida typically occur in the months of May through October, these months were chosen to be the months of the study. During this time, there were five periods of El Nino and two periods of La Nina, with a neutral period separating each oscillation. In order to eliminate rainfall from systems other than sea breeze thunderstorms, only days that were conducive to the development of a sea breeze front were selected.

The seasonal characteristics of the breeze circulation at a coastal Mediterranean site in South Italy

DEFF Research Database (Denmark)

Federico, S.; Pasqualoni, L.; Sempreviva, Anna Maria

2010-01-01

We present a study on the characteristics of the sea breeze flow at a coastal site located in the centre of the Mediterranean basin at the southern tip of Italy. This study is finalized to add new data on breeze circulations over a narrow peninsula and present a unique experimental coastal site...... at about 600 m from the coastline in a flat open area at the foot of a mountain chain located in a region of complex orography. We study the seasonal behaviour of the sea-land breeze circulation by analysing two years of hourly data of wind speed and direction, temperature, radiation and relative humidity...

Spatial and Temporal Changes in Air Pollution Along the Gulf Coast Observed During BRACE: A Case Study of the Land-Sea Breeze

Science.gov (United States)

Wellman, D.; Luke, W.; Arnold, J.; Watson, T.; Gunter, L.

2003-12-01

NOAA's Air Resources Laboratory conducted airborne measurements of trace gases and aerosols in the Bay Region Atmospheric Chemistry Experiment (BRACE) using the NOAA Twin Otter. The Twin Otter flew more than 90 hours in 21 flights in and around the Tampa metropolitan region in May, 2002, at altitudes of 60-3000 m MSL. Flights were conducted over rural and suburban areas, over the centers of Tampa and St. Petersburg, and over Tampa Bay and the Gulf of Mexico. One objective of the aircraft flights was to investigate the role of the sea breeze circulation in determining patterns of nutrient deposition and pollutant loads in the Tampa Bay watershed. Results will be presented from a May 8 flight designed to investigate the effect of the sea breeze recirculation upon Tampa's air quality. The Twin Otter took off at 1425 UTC and after performing a spiral ascent over the Sydney ground site, proceeded to fly north, at 200 feet above mean sea level (MSL) just off the Gulf coast, west of St. Petersburg. Back trajectory analysis suggested the dominance of a northerly rotation in the sea breeze; thus, air sampled over the Gulf passed some hours earlier to the south of the Tampa metropolitan area, in an area largely devoid of major pollution sources, before being advected eastward in the afternoon return flow. Ozone levels in this air mass ranged from 40 to 50 ppbv. Farther north the Twin Otter encountered the advected urban plume from Tampa, displaced to the north by the combination of southeasterly sea breeze flow and westerly return flow, and tracked this plume inland. Ozone levels quickly jumped to 60 ppbv, and increased to as high as 90 ppbv as photochemical processing continued in the advected plume. Nitric acid levels, which approached 4 ppbv in the aged urban air at the coast, dropped rapidly to as low as 1 ppbv inland. A final flight leg to the east of downtown Tampa encountered fresh anthropogenic pollution from the afternoon rush hour; ozone was rapidly produced in the

Interactions between the thermal internal boundary layer and sea breezes

Energy Technology Data Exchange (ETDEWEB)

Steyn, D.G. [The Univ. of British Columbia, Dept. of Geography, Atmospheric Science Programme, Vancouver (Canada)

1997-10-01

In the absence of complex terrain, strongly curved coastline or strongly varying mean wind direction, the Thermal Internal Boundary Layer (TIBL) has well known square root behaviour with inland fetch. Existing slab modeling approaches to this phenomenon indicate no inland fetch limit at which this behaviour must cease. It is obvious however that the TIBL cannot continue to grow in depth with increasing fetch, since the typical continental Mixed Layer Depths (MLD) of 1500 to 2000 m must be reached between 100 and 200 km from the shoreline. The anticyclonic conditions with attendant strong convection and light winds which drive the TIBL, also drive daytime Sea Breeze Circulations (SBC) in the coastal zone. The onshore winds driving mesoscale advection of cool air are at the core of TIBL mechanisms, and are invariably part of a SBC. It is to be expected that TIBL and SBC be intimately linked through common mechanisms, as well as external conditions. (au)

Temperature And Wind Velocity Oscillations Along a Gentle Slope During Sea-Breeze Events

Science.gov (United States)

Bastin, Sophie; Drobinski, Philippe

2005-03-01

The flow structure on a gentle slope at Vallon d’Ol in the northern suburbs of Marseille in southern France has been documented by means of surface wind and temperature measurements collected from 7 June to 14 July 2001 during the ESCOMPTE experiment. The analysis of the time series reveals temperature and wind speed oscillations during several nights (about 60--90 min oscillation period) and several days (about 120-180 min oscillation period) during the whole observing period. Oscillating katabatic winds have been reported in the literature from theoretical, experimental and numerical studies. In the present study, the dynamics of the observed oscillating katabatic winds are in good agreement with the theory.In contrast to katabatic winds, no daytime observations of oscillating anabatic upslope flows have ever been published to our knowledge, probably because of temperature inversion break-up that inhibits upslope winds. The present paper shows that cold air advection by a sea breeze generates a mesoscale horizontal temperature gradient, and hence baroclinicity in the atmosphere, which then allows low-frequency oscillations, similar to a katabatic flow. An expression for the oscillation period is derived that accounts for the contribution of the sea-breeze induced mesoscale horizontal temperature gradient. The theoretical prediction of the oscillation period is compared to the measurements, and good agreement is found. The statistical analysis of the wind flow at Vallon d’Ol shows a dominant north-easterly to easterly flow pattern for nighttime oscillations and a dominant south-westerly flow pattern for daytime oscillations. These results are consistent with published numerical simulation results that show that the air drains off the mountain along the maximum slope direction, which in the studied case is oriented south-west to north-east.

Investigation of enhanced cross-city transport and trapping of air pollutants by coastal and urban land-sea breeze circulations

Science.gov (United States)

Lo, Jeff C. F.; Lau, Alexis K. H.; Fung, Jimmy C. H.; Chen, Fei

2006-07-01

Recent satellite observations show that a layer of haze perpetually hangs over the Pearl River Delta (PRD) region and surface observations show numerous violations of the Hong Kong Air Quality Objective. This layer of haze mostly concentrates in the Pearl River Estuary and a narrow (20 km wide) band along the shoreline, in particular during weak wind situations. Although researchers suspect the land-sea breeze (LSB) circulations "concentrate" or "trap" various pollutants in this region, the physical mechanism of the phenomenon has never been fully explained or quantified. In this paper, a mesoscale atmospheric model (MM5) coupled with the Noah land surface model (LSM), which has bulk urban land use treatments along with a detailed Pearl River Delta land use map, is used to investigate the unique feature and mechanism of this land-sea breeze effect and the temporal evolution. A three-dimensional particle trajectory model is used to understand its associated pollutant transport, trapping and accumulation. A conceptual model is then developed for the perpetual air pollution phenomenon in the region. Further sensitivity experiments are used to illustrate the impact of urbanization and large-scale winds on the pollution processes. Results show that urbanization enhances the pollutant trapping and therefore contributes to the overall poor air quality in the region.

Modelling study of sea breezes in a complex coastal environment

Science.gov (United States)

Cai, X.-M.; Steyn, D. G.

This study investigates a mesoscale modelling of sea breezes blowing from a narrow strait into the lower Fraser valley (LFV), British Columbia, Canada, during the period of 17-20 July, 1985. Without a nudging scheme in the inner grid, the CSU-RAMS model produces satisfactory wind and temperature fields during the daytime. In comparison with observation, the agreement indices for surface wind and temperature during daytime reach about 0.6 and 0.95, respectively, while the agreement indices drop to 0.4 at night. In the vertical, profiles of modelled wind and temperature generally agree with tethersonde data collected on 17 and 19 July. The study demonstrates that in late afternoon, the model does not capture the advection of an elevated warm layer which originated from land surfaces outside of the inner grid. Mixed layer depth (MLD) is calculated from model output of turbulent kinetic energy field. Comparison of MLD results with observation shows that the method generates a reliable MLD during the daytime, and that accurate estimates of MLD near the coast require the correct simulation of wind conditions over the sea. The study has shown that for a complex coast environment like the LFV, a reliable modelling study depends not only on local surface fluxes but also on elevated layers transported from remote land surfaces. This dependence is especially important when local forcings are weak, for example, during late afternoon and at night.

Florida Agriculture - Utilizing TRMM to Analyze Sea Breeze Thunderstorm Patterns During El Nino Southern Oscillations and Their Effects Upon Available Fresh Water for South Florida Agricultural Planning and Management

Science.gov (United States)

Billiot, Amanda; Lee, Lucas; McKee, Jake; Cooley, Zachary Clayton; Mitchell, Brandie

2010-01-01

This project utilizes Tropical Rainfall Measuring Mission (TRMM) and Landsat satellite data to assess the impact of sea breeze precipitation upon areas of agricultural land use in southern Florida. Water is a critical resource to agriculture, and the availability of water for agricultural use in Florida continues to remain a key issue. Recent projections of statewide water use by 2020 estimate that 9.3 billion gallons of water per day will be demanded, and agriculture represents 47% of this demand (Bronson 2003). Farmers have fewer options for water supplies than public users and are often limited to using available supplies from surface and ground water sources which depend in part upon variable weather patterns. Sea breeze thunderstorms are responsible for much of the rainfall delivered to Florida during the wet season (May-October) and have been recognized as an important overall contributor of rainfall in southern Florida (Almeida 2003). TRMM satellite data was used to analyze how sea breeze-induced thunderstorms during El Nino and La Nina affected interannual patterns of precipitation in southern Florida from 1998-2009. TRMM's Precipitation Radar and Microwave Imager provide data to quantify water vapor in the atmosphere, precipitation rates and intensity, and the distribution of precipitation. Rainfall accumulation data derived from TRMM and other microwave sensors were used to analyze the temporal and spatial variations of rainfall during each phase of the El Nino Southern Oscillation (ENSO). Through the use of TRMM and Landsat, slight variations were observed, but it was determined that neither sea breeze nor total rainfall patterns in South Florida were strongly affected by ENSO during the study period. However, more research is needed to characterize the influence of ENSO on summer weather patterns in South Florida. This research will provide the basis for continued observations and study with the Global Precipitation Measurement Mission.

Changes in nearshore waves during the active sea/land breeze period off Vengurla, central west coast of India

Digital Repository Service at National Institute of Oceanography (India)

Amrutha, M.M.; SanilKumar, V.; Singh, J.

zones with use of mechanized boats and this area is also extensively used for tourism-related activities. Therefore, it is important to un- derstand the changes in wave parameters during the active land/sea breeze system in the nearshore region... and interaction. The wave computations in Delft3D-wave are stable due to the fully implicit schemes that have been implemented. In the Delft3D-wave module, the governing equation of wave transformation is based on action balance spectrum, in ge- ographical space...

Identifying and tracking plumes affected by an ocean breeze in support of emergency preparedness

International Nuclear Information System (INIS)

Schwartz, P.E.

1989-01-01

To better support emergency preparedness, General Public Utilities (GPU) Nuclear has investigated the frequency of occurrence of the mesoscale ocean breeze at the Oyster Creek Nuclear Generating Station (OCNGS). Through the analysis of the horizontal wind direction and temperature patterns, simple identification of the ocean breeze along with a plume tracking procedure has been developed and incorporated into the site's emergency plant to better safeguard the public with sophisticated protective action measures in case of a nonroutine release. The ocean breeze will frequently produce wind trajectory fields within the plant's emergency planning zone that are different from the normal gradient wind flow. This could greatly alter proper protective action measures since most utilities employ straight-line trajectory air dispersion models. Knowledge of the existence of the ocean breeze and the location of the ocean breeze front become important in the results generated from the straight-line Gaussian dose calculation methodology and in the further development of a more complex dose assessment model. This paper describes the verification and existence of the sea breeze phenomenon and the incorporation of its effects into the OCNGS emergency plan

A Coastal Bay Summer Breeze Study, Part 1: Results of the Quiberon 2006 Experimental Campaign

Science.gov (United States)

Mestayer, Patrice G.; Calmet, Isabelle; Herlédant, Olivier; Barré, Sophie; Piquet, Thibaud; Rosant, Jean-Michel

2018-04-01

The Quiberon 2006 experiment was launched to document the onset and development of land and sea breezes over a semi-circular coastal bay propitious to inshore sailing competitions. The measurements were taken during the 2 weeks of 16-28 June 2006. Micrometeorological variables were recorded at three shore sites around the bay using turbulence sensors on 10-30-m high masts, on four instrumented catamarans at selected sites within the bay, and at a fourth shore site with a Sodar. Synoptic data and local measurements are analyzed here from the point of view of both micrometeorologists and competition skippers, testing in particular the empirical rules of breeze veering and backing according to the wind direction with respect to the coastline orientation at the mesoscale (the quadrant theory). Our analysis focuses on the patterns of lower-altitude wind direction and speed around the bay and over the water basin, and the temporal variations during the periods of the breeze onset, establishment and thermal reinforcement. In offshore synoptic-flow conditions (quadrants 1 and 2), the clockwise rotation of the surface flow had a very large amplitude, reaching up to 360°. The breeze strength was negatively correlated to that of the synoptic wind speed. In conditions of onshore synoptic flow from the west (quadrant 3) at an angle to the mainland coast but perpendicular to the Quiberon peninsula, the rotation of the flow was backwards in the early morning and clockwise during the day with a moderate amplitude (40°-50°) around the synoptic wind direction. As the surface wind speed was much larger than the synoptic wind speed, such a case we have designated as a "synoptic breeze". The breeze onset was shown to fail several times under the influence of weak non-thermal events, e.g., the passage of an occluded front or clouds or an excess of convection. Finally, several local-scale influences of the complex coastal shape appeared in our measurements, e.g., wind fanning in the

Uma teoria termodinâmica para brisas: teste utilizando simulações numéricas A thermodynamic theory for breezes: test using numeric simulations

Directory of Open Access Journals (Sweden)

Clênia Rodrigues Alcântara

2008-03-01

Full Text Available O objetivo deste trabalho foi testar uma teoria termodinâmica em brisas marítimas-terrestres acopladas com brisas de vale-montanha através de simulações numéricas tridimensionais em uma região da costa leste do Nordeste Brasileiro, considerando a presença e a ausência da topografia. Embora o contraste de temperatura entre as superfícies seja importante na formação da brisa, a eficiência termodinâmica é fundamental na determinação da sua intensidade. Tem-se que a inclinação faz com que a diferença de pressão entre dois pontos fique maior durante o dia e menor durante a noite contribuindo para a formação de brisas marítimas mais intensas e de brisas terrestres menos intensas, respectivamente. A máxima queda de pressão ocorre por volta de três horas antes da máxima intensidade da brisa. Isso porque grande parte da energia disponibilizada para as circulações é gasta para vencer dissipação, principalmente, no período diurno, quando esses processos são realmente efetivos. Do ponto de vista puramente termodinâmico a inclinação da montanha atua para intensificar a brisa durante o dia e para enfraquecê-la durante a noite.In this work we test a thermodynamic theory for sea-land breeze coupled with valley-mountain breeze through tri-dimensional numeric simulations. We verify the presence of such a breeze in Northeast Brazil's east coast and perform experiments with and without the topography of the region. Although the temperature contrast between two surfaces is important in forming the breezes, the thermodynamic efficiency is a key parameter for the breeze intensity. The presence of the slope causes the pressure difference between two points to increase during the day and to decrease during the night. This contributes for more intense daytime breeze and less intense nighttime ones. The maximum pressure drop occurs about three hours prior the maximum intensity of the sea breeze. This is because most of the available

Radial diffusive samplers for determination of 8-h concentration of BTEX, acetone, ethanol and ozone in ambient air during a sea breeze event

Science.gov (United States)

Roukos, Joelle; Locoge, Nadine; Sacco, Paolo; Plaisance, Hervé

2011-01-01

The radial diffusive sampler Radiello ® filled with Carbograph 4 was evaluated for monitoring BTEX, ethanol and acetone concentrations for 8-hour exposure time. The sampling rates were first evaluated in an exposure chamber under standard conditions. Benzene and toluene showed the highest sampling rates with satisfactory standard deviations. Ethylbenzene and xylenes showed medium sampling rates but higher standard deviations that can be attributed to a low affinity of these compounds with the adsorbent medium for short sampling time. Acetone has a fair result because of the increase of its partial pressure in the vicinity of the adsorbent surface in the course of sampling. The Carbograph 4 adsorbent does not seem to be suitable for sampling ethanol, likely because of its high volatility. The influences of three environmental factors (temperature (T), relative humidity (RH) and concentration level (C)) on the sampling rates were also evaluated, following a fractional factorial design at two factor levels (low and high). Results were only investigated on benzene, toluene and acetone. Temperature and relative humidity are found to be the most important factors leading to variability of the benzene and toluene sampling rates. The applicability of the sampler for 8-hour sampling was demonstrated by the results of a measurement campaign carried out during a sea breeze event. Mapping of benzene, toluene and acetone concentrations showed the highest concentrations in the industrial zone following the wind direction coming from the North. Nevertheless, the sea breeze tends to reduce the spread of the industrial plumes. On the contrary, the ozone map presents the lowest concentrations at the same industrial area indicating a net consumption of ozone. The highest ozone concentrations were found in the southeastern zone suggesting a local ozone formation.

Granulation of coke breeze fine for using in the sintering process

Directory of Open Access Journals (Sweden)

Mohamed F.M.

2010-01-01

Full Text Available Coke breeze is the main fuel used in the sintering process. The value of -3+1 mm. represents the most favorable particle size for coke breeze in the sintering process. About 20% of total coke fines (-0.5 mm are produced during different steps of preparation. Introducing these fines during the sintering process proves to be very harmful for different operating parameters. Thus ,this study aims at investigating the production of granules resulting from these fines using molasses as organic binder and its application in sintering of an iron ore. The results showed that the granules having the highest mechanical properties were obtained with 14.5 wt % molasses addition. The sintering experiments were performed by using coke breeze in different shapes (-3+1 mm in size, coke breeze without sieving and coke breeze granules -3+1 mm. The reduction experiments, microscopic structure and X-ray analysis for the produced sinter were carried out. The results revealed that, all sinter properties (such as shatter test, productivity of sinter machine and blast furnace, reduction time and chemical composition for produced sinter by using coke breeze with size -3+1 mm and coke breeze granules were almost the same. The iron ore sinter which was produced by using coke breeze without sieving yielded low productivity for both sinter machine and blast furnace. Furthermore, using coke breeze without sieving in sintering of an iron ore decreases the vertical velocity of sinter machine and increases the reduction time.

3D Structures of the Sea-Breeze Front in Dual-Doppler Lidar Analysis and a State-of-the-Art Modeling System

Science.gov (United States)

Chen, G.; Iwai, H.; Seko, H.; Saito, K. K.; Sha, W.; Iwasaki, T.

2017-12-01

Sea breeze occurs at coastal regions around the world, with great impacts on the weather and air quality. Observations and forecasts of the fine-scale structures and local impacts of sea-breeze front (SBF) are a challenge. Three-dimensional structures of a quasi-stationary SBF were observed by dual-Doppler lidar over Sendai Airport in June 2007. Using a state-of-the-art local prediction system in which a computational fluid dynamics model is nested to a mesoscale model with data assimilation, we perform a realistic simulation of the observed SBF structures at 10-m resolution. Numerical simulations reproduce the detailed features of the SBF, such as frontal lobes/clefts, intense updrafts, rear downdrafts, and Kelvin-Helmholtz billows, consistent with lidar observations. Several localized maxima of updrafts occur at the active SBF lobes with ascending marine air mass and adjacent windward sides, where the ambient warm flows encounter a steep front face and penetrate SBF aloft. Strong downdrafts of marine cool air dominate at the SBF rear where they trap a high concentration of air pollutants. These features are regularly activated by the arc-shaped gravity currents at a horizontal scale of several kilometers and a period of 30 minutes. They are also influenced by the coastal buildings and strongly regulate the spatio-temporal variations of local winds near surface. The findings suggest that a novel full-scale nested prediction system has potential for forecasting coastal weather and environment at high precision, which are valuable for aviation safety, marine activities, and air quality monitoring. AcknowledgmentsThis study was supported by the Strategic Programs for Innovative Research (SPIRE) funded by the Japan Ministry of Education, Culture, Sports, Science and Technology (MEXT). The numerical calculations were performed using the K computer at RIKEN Advanced Institute for Computational Science (Proposal numbers hp130012 and hp140220). The observational data were

Observations of Lake-Breeze Events During the Toronto 2015 Pan-American Games

Science.gov (United States)

Mariani, Zen; Dehghan, Armin; Joe, Paul; Sills, David

2018-01-01

Enhanced meteorological observations were made during the 2015 Pan and Parapan American Games in Toronto in order to measure the vertical and horizontal structure of lake-breeze events. Two scanning Doppler lidars (one fixed and one mobile), a C-band radar, and a network including 53 surface meteorological stations (mesonet) provided pressure, temperature, humidity, and wind speed and direction measurements over Lake Ontario and urban areas. These observations captured the full evolution (prior, during, and after) of 27 lake-breeze events (73% of observation days) in order to characterize the convective and dynamic processes driving lake breezes at the local scale and mesoscale. The dominant signal of a passing lake-breeze front (LBF) was an increase in dew-point temperature of 2.3 ± 0.3°C, coinciding with a 180° shift in wind direction and a decrease in air temperature of 2.1 ± 0.2°C. Doppler lidar observations over the lake detected lake breezes 1 hour (on average) before detection by radar and mesonet. On days with the synoptic flow in the offshore direction, the lidars observed wedge-shaped LBFs with shallow depths, which inhibited the radar's ability to detect the lake breeze. The LBF's ground speed and inland penetration distance were found to be well-correlated (r = 0.78), with larger inland penetration distances occurring on days with non-opposing (non-offshore) synoptic flow. The observed enhanced vertical motion ({>} 1 m s^{-1}) at the LBF, observed by the lidar on 54% of lake-breeze days, was greater (at times {>} 2.5 m s^{-1}) than that observed in previous studies and longer-lasting over the lake than over land. The weaker and less pronounced lake-breeze structure over land is illustrated in two case studies highlighting the lifetime of the lake-breeze circulation and the impact of propagation distance on lake-breeze intensity.

Teoria para o trabalho de expansão aplicada às brisas do nordeste Brasileiro Theory for expansion work applied to breezes of Northeast of Brazil

Directory of Open Access Journals (Sweden)

Clênia R. Alcântara

2009-12-01

Full Text Available Neste artigo investiga-se numericamente a interação entre brisas marítima-terrestre e de vale-montanha, que ocorrem no nordeste brasileiro devido à presença do Planalto da Borborema, aplicando o trabalho de expansão associado ao ramo inferior das circulações. Resultados da teoria da máquina térmica são comparados aos resultados 3D, obtidos com a versão brasileira do modelo RAMS. Os resultados indicaram que o efeito do contraste de temperatura no trabalho ligado às circulações (Wa, isoladamente, contribui para a formação de brisas marítimas mais intensas e de brisas terrestres menos intensas. Na realidade, o que se observa são brisas terrestres com intensidades iguais ou até maiores que das brisas marítimas. Assim, a contribuição da montanha para a intensidade das circulações de brisa no período noturno mostra-se extremamente não-linear. O trabalho de expansão que realmente está ligado às circulações, contribui em apenas 7% para o trabalho total. Dessa forma, a maior parte do trabalho total está associada ao trabalho de compressão que a atmosfera realiza para compensar a perda por resfriamento radiativo, e muito da energia disponibilizada para as circulações é gasta para vencer os processos dissipativos.The purpose of this work is to further understand the interactions between sea-land breeze and valley-mountain breeze that occur at the coast of Northeast Brazil due to the presence of the Borborema plateau, using the associated expansion work at the lower branch of these circulations. Results of the thermal machine theory are compared to the 3D results obtained from the Brazilian RAMS model version. The results indicate that the sole effect of temperature contrast on the work associated with circulations (Wa is more intense sea breezes and weaker land breezes. Actually, one can observe land breezes whose intensities are equal or even larger than sea breezes. Thus, the mountain contribution for the intensity of

Inclusion of the ocean breeze in Oyster Creek emergency off-site dose assessment

International Nuclear Information System (INIS)

Heck, W.

1986-01-01

The Oyster Creek Nuclear Generating Station (OCNGS) is located 6 mi west of the Atlantic Ocean. From spring through late summer, atmospheric transport in the vicinity of OCNGS is periodically affected by the ocean breeze. The ocean breeze produces large differences in wind direction within the OCNGS emergency planning zone during the morning to evening hours. In addition, trajectory reversals can occur near the ocean breeze front. These two characteristics of the ocean breeze must be taken into account when interpreting results from conventional atmospheric dispersion models. The purpose of the study was to determine the flow characteristics of the ocean breeze and to apply these characteristics to an emergency preparedness implementing procedure (EPIP). The EPIP would be used to determine the radiological plume impact region if an accidental release occurred during an ocean breeze

NASA's Newest SeaWinds Instrument Breezes Into Operation

Science.gov (United States)

2003-01-01

One of NASA's newest Earth-observing instruments, the SeaWinds scatterometer aboard Japan's Advanced Earth Observing Satellite (Adeos) 2--now renamed Midori 2--has successfully transmitted its first radar data to our home planet, generating its first high-quality images.From its orbiting perch high above Earth, SeaWinds on Midori 2 ('midori' is Japanese for the color green, symbolizing the environment) will provide the world's most accurate, highest resolution and broadest geographic coverage of ocean wind speed and direction, sea ice extent and properties of Earth's land surfaces. It will complement and eventually replace an identical instrument orbiting since June 1999 on NASA's Quick Scatterometer (QuikScat) satellite. Its three- to five-year mission will augment a long-term ocean surface wind data series that began in 1996 with launch of the NASA Scatterometer on Japan's first Adeos spacecraft.Climatologists, meteorologists and oceanographers will soon routinely use data from SeaWinds on Midori 2 to understand and predict severe weather patterns, climate change and global weather abnormalities like El Nino. The data are expected to improve global and regional weather forecasts, ship routing and marine hazard avoidance, measurements of sea ice extent and the tracking of icebergs, among other uses.'Midori 2, its SeaWinds instrument and associated ground processing systems are functioning very smoothly,' said Moshe Pniel, scatterometer projects manager at NASA's Jet Propulsion Laboratory, Pasadena, Calif. 'Following initial checkout and calibration, we look forward to continuous operations, providing vital data to scientists and weather forecasters around the world.' 'These first images show remarkable detail over land, ice and oceans,' said Dr. Michael Freilich, Ocean Vector Winds Science Team Leader, Oregon State University, Corvallis, Ore. 'The combination of SeaWinds data and measurements from other instruments on Midori 2 with data from other international

Surf Zone Sediment Size Variation, Morphodynamics, and Hydrodynamics During Sea/Land Breeze and El-Norte Storm in Sisal, Yucatan, Mexico

Science.gov (United States)

Alrushaid, T.; Figlus, J.; Torres-Freyermuth, A.; Puleo, J. A.; Dellapenna, T. M.

2016-02-01

Coastlines around the world are under ever-increasing pressure due to population trends, commerce, and geophysical processes like tropical storms and erosion. This multi-institutional field campaign was conducted to improve our understanding of complex nearshore processes under varying forcing conditions on a microtidal, sandy beach located in Sisal, Yucatan from 3/27 to 4/12/2014. Hydrodynamics, morphodynamics, and textural variability were investigated during: (1) a cold front event (referred to as El-Norte); (2) land breeze (LB); and (3) sea breeze (SB). The instrumentation layout included three surf/swash zone cross-shore transects where water elevation, suspended sediment concentration, bed load, and current velocities were measured, as well as several offshore ADCP for hydrodynamic measurements. TKE, τb, ɛ and were estimated using the data obtained from surf zone ADV. In addition, Hs and Tsin the surf zone were computed using measurements from ADV pressure sensors, while a separate pressure transducer was used to obtain water free-surface elevation within the swash zone. During SB cycles the study area experienced wind velocities reaching up to 12ms-1, and 15ms-1 during El-Norte. Elevated wind stress during El-Norte resulted in Hs of 1.5m and 0.6m in water depths of 10m and 0.4m, respectively. Surface sediment grab samples during SB/LB cycles showed that the swash zone had a moderately well sorted distribution with a mean grain size of 0.5mm, while poor sorting and a mean grain size of 0.7mm were found during El-Norte. Additionally, measured bathymetry data showed evidence for offshore sandbar migration during strong offshore currents (0.4ms-1) during El-Norte, while onshore sandbar migration was evident during SB/LB periods (0.3ms-1 and 0.1ms-1, respectively). This study highlights how different weather forcing conditions affect hydrodynamics, morphodynamics, and textural variability on a sandy beach. Aside from furthering our knowledge on these complex

Study of the thermal internal boundary layer during sea-breeze events in the complex coastal area of Marseille

Science.gov (United States)

Calmet, Isabelle; Mestayer, Patrice

2016-02-01

A revisit of two sea-breeze episodes is presented, based on higher spatial resolution large eddy simulations (LES) of the lower atmosphere over the coastal area of Marseille and measurements obtained during the June 2001 experimental campaign UBL-ESCOMPTE. The focus is on the development of thermal internal boundary layers (TIBL) over a complex topography: the dynamic and thermal mechanisms that contribute to the TIBL growth and its further degeneration into a convective mixed layer, the respective influences of the coast shape, the large-scale flow above and the local low-level slope flows. The high-resolution LES permits exploring the potential temperature and turbulent kinetic energy fields in relation with the evolution of TIBL depth and heat fluxes along representative streamlines. Several theoretical TIBL depth models are further compared to the LES-deduced inversion height and other parameters, leading to a discussion of the relationships between the values of these parameters, the respective influences of the governing physical phenomena, and the TIBL behaviour. A threshold value of 0.35 is proposed for the friction velocity to convective velocity scale ratio u */ w * between the two regimes where the TIBL is either dominated by dynamical kinetic energy production or controlled by buoyancy.

Regional Hydrological Cycle over the Red Sea in ERA-Interim

KAUST Repository

Zolina, Olga; Dufour, Ambroise; Gulev, Sergey K.; Stenchikov, Georgiy L.

2016-01-01

The major sources of atmospheric moisture over the Red Sea are analyzed using ERA-Interim for the 1979-2013 period. The vertical structure of moisture transports across the coastlines has been computed separately for the western and eastern coasts of the Red Sea. The vertical structure of the moisture transport from the Red Sea to the continents is dominated by a breeze-like circulation in the near-surface layer and the Arabian high above 850 hPa. The lower-layer, breeze-like circulation is acting to export the moisture to the northwest of Africa and to the Arabian Peninsula and contributes about 80% of the moisture exports from the Red Sea, dominating over the transport in the upper layer, where the moisture is advected to the Arabian Peninsula in the northern part of the sea and to the African continent in the southern part. Integrated moisture divergence over the Red Sea decreased from the early 1980s to 1997 and then increased until the 2010s. Associated changes in the moisture export were provided primarily by the increasing intensity of the breeze-associated transports. The transports above the boundary layer, while being strong across the western and the eastern coasts, have a smaller effect on the net moisture export. The interannual variability of the moisture export in the near-surface layer was found to be closely correlated with the variability in sea surface temperature, especially in summer. Implications of the observed changes in the moisture advection for the hydrological cycle of the Middle East are discussed.

Regional Hydrological Cycle over the Red Sea in ERA-Interim

KAUST Repository

Zolina, Olga

2016-09-30

The major sources of atmospheric moisture over the Red Sea are analyzed using ERA-Interim for the 1979-2013 period. The vertical structure of moisture transports across the coastlines has been computed separately for the western and eastern coasts of the Red Sea. The vertical structure of the moisture transport from the Red Sea to the continents is dominated by a breeze-like circulation in the near-surface layer and the Arabian high above 850 hPa. The lower-layer, breeze-like circulation is acting to export the moisture to the northwest of Africa and to the Arabian Peninsula and contributes about 80% of the moisture exports from the Red Sea, dominating over the transport in the upper layer, where the moisture is advected to the Arabian Peninsula in the northern part of the sea and to the African continent in the southern part. Integrated moisture divergence over the Red Sea decreased from the early 1980s to 1997 and then increased until the 2010s. Associated changes in the moisture export were provided primarily by the increasing intensity of the breeze-associated transports. The transports above the boundary layer, while being strong across the western and the eastern coasts, have a smaller effect on the net moisture export. The interannual variability of the moisture export in the near-surface layer was found to be closely correlated with the variability in sea surface temperature, especially in summer. Implications of the observed changes in the moisture advection for the hydrological cycle of the Middle East are discussed.

Observational analysis of air-sea fluxes and sea water temperature offshore South China Sea

Science.gov (United States)

Bi, X.; Huang, J.; Gao, Z.; Liu, Y.

2017-12-01

This paper investigates the air-sea fluxes (momentum flux, sensible heat flux and latent heat flux) from eddy covariance method based on data collected at an offshore observation tower in the South China Sea from January 2009 to December 2016 and sea water temperature (SWT) on six different levels based on data collected from November 2011 to June 2013. The depth of water at the tower over the sea averages about 15 m. This study presents the in-situ measurements of continuous air-sea fluxes and SWT at different depths. Seasonal and diurnal variations in air-sea fluxes and SWT on different depths are examined. Results show that air-sea fluxes and all SWT changed seasonally; sea-land breeze circulation appears all the year round. Unlike winters where SWT on different depths are fairly consistent, the difference between sea surface temperature (SST) and sea temperature at 10 m water depth fluctuates dramatically and the maximum value reaches 7 °C during summer.

Meteorological observations of the coastal boundary layer structure by remote measurement methods for determining the impact of meteorological conditions on the breeze circulation

Science.gov (United States)

Barantiev, D.

2010-09-01

Continuous measurements of the characteristics of atmospheric boundary layer and the characteristics of breeze circulation were initiated at the meteorological observatory of Ahtopol on the Black Sea coast (south-east Bulgaria) under a Bulgarian-Russian collaborative programme. Research observations started in July 2008 and go on. These observations are the start of high resolution atmospheric boundary layer vertical structure climatology at a Bulgarian Black Sea coastal site. Automatic weather station «MK-15» with an acoustic anemometer (mounted at 4,5m height) and Flat Array Sodar without RASS extension «Scintec» were installed on polygon of Ahtopol. A preliminary analysis was made of the experimental data on the thermodynamic structure of the atmospheric boundary layer in the coastal zone. Vertical profiles of wind speed, direction and spatio-temporal sectional were constructed according to the sodar data. Graphs of temporal variations of the direction and modulus of wind velocity, vertical velocity, the standard deviation of the acoustic temperature and time variation of air temperature (at a height of 2m - standard synoptic measurements) were constructed according MK-15. The momentum u* = " - w-'u' and sensible heat H = w'T' surface turbulent fluxes were calculated from MK-15 raw data. Prevailing weather conditions contributing to breeze circulation in the area were investigated. Blurred pressure field of high pressure with warm air mass, clear and (or) the overcast weather was characterized for treatment cases. The average wind speed near the ground was did not exceed 3 m/s, with a ripple rate of up to 4 m/s according to MK-15. The nature of the wind changed direction during the day has been practically the same (i.e., diurnal repeats) in all cases. The breeze front location was also detected based on standard measurements in the surface layer (mean values of temperature at 2 m and wind speed and direction from MK-15). In the zone of the front the wind

WARM BREEZE FROM THE STARBOARD BOW: A NEW POPULATION OF NEUTRAL HELIUM IN THE HELIOSPHERE

Energy Technology Data Exchange (ETDEWEB)

Kubiak, M. A.; Bzowski, M.; Sokół, J. M.; Swaczyna, P.; Grzedzielski, S. [Space Research Centre of the Polish Academy of Sciences, Warsaw (Poland); Alexashov, D. B.; Izmodenov, V. V. [Space Research Institute (IKI) of the Russian Academy of Sciences, Moscow (Russian Federation); Möbius, E.; Leonard, T. [Space Research Center and Department of Physics, University of New Hampshire, Durham, NH (United States); Fuselier, S. A.; McComas, D. J. [Southwest Research Institute, San Antonio, TX (United States); Wurz, P. [Physics Institute, University of Bern, Bern (Switzerland)

2014-08-01

We investigate the signals from neutral helium atoms observed in situ from Earth orbit in 2010 by the Interstellar Boundary Explorer (IBEX). The full helium signal observed during the 2010 observation season can be explained as a superposition of pristine neutral interstellar He gas and an additional population of neutral helium that we call the Warm Breeze. The Warm Breeze is approximately 2 times slower and 2.5 times warmer than the primary interstellar He population, and its density in front of the heliosphere is ∼7% that of the neutral interstellar helium. The inflow direction of the Warm Breeze differs by ∼19° from the inflow direction of interstellar gas. The Warm Breeze seems to be a long-term, perhaps permanent feature of the heliospheric environment. It has not been detected earlier because it is strongly ionized inside the heliosphere. This effect brings it below the threshold of detection via pickup ion and heliospheric backscatter glow observations, as well as by the direct sampling of GAS/Ulysses. We discuss possible sources for the Warm Breeze, including (1) the secondary population of interstellar helium, created via charge exchange and perhaps elastic scattering of neutral interstellar He atoms on interstellar He{sup +} ions in the outer heliosheath, or (2) a gust of interstellar He originating from a hypothetic wave train in the Local Interstellar Cloud. A secondary population is expected from models, but the characteristics of the Warm Breeze do not fully conform to modeling results. If, nevertheless, this is the explanation, IBEX-Lo observations of the Warm Breeze provide key insights into the physical state of plasma in the outer heliosheath. If the second hypothesis is true, the source is likely to be located within a few thousand AU from the Sun, which is the propagation range of possible gusts of interstellar neutral helium with the Warm Breeze characteristics against dissipation via elastic scattering in the Local Cloud. Whatever the

Ocean breeze monitoring network at the Oyster Creek Nuclear Plant

International Nuclear Information System (INIS)

Heck, W.

1987-01-01

The Oyster Creek Nuclear Generating Station (OCNGS) is located in New Jersey 10 km west of the Atlantic Ocean. Routine meteorological monitoring at the station has consisted of a single meteorological tower 120 m high and instrumented at the 10-m, 46-m, and 116-m levels. An analysis of 5 yr of data from this tower showed the OCNGS is affected by an ocean breeze ∼ 1 day out of 4 during May through August. This suggested the need for meteorological monitoring in addition to the single met tower at OCNGS. As a result of the 1985 OCNGS meteorological monitoring study, GPU Nuclear established an ocean breeze monitoring network in the fall of 1986. It is a permanent part of OCNGS meteorological monitoring and consists of the same sites as used in the 1985 field study. Meteorological towers are located at the ocean site, the inland site, and at OCNGS. The ocean tower is 13 m (43 ft) high, the inland tower 10 m (33 ft), and the OCNGS tower 116 m (380 ft). Wind speed, wind direction, and temperature are measured on each tower; delta-temperature is also measured on the main tower. The instruments are calibrated in the spring, summer, and fall. The network is operated and maintained by GPU Nuclear Environmental Controls. The ocean breeze monitoring network and meteorological information system forms the basis for including the effects of the ocean breeze in OCNGS emergency off-site dose assessment

Analysis of hydrodynamic characteristics of unmanned underwater vehicle moving close to the sea bottom

Directory of Open Access Journals (Sweden)

Xiao-xu Du

2014-03-01

Full Text Available The accurate research on the hydrodynamics of unmanned underwater vehicle (UUV, which moves close to the sea bottom, has a great significance for its maneuverability. The structured grid of the computational models with different distances to the sea bottom and attack angles is generated by Ansys ICEM, and the flow field near the sea bottom is simulated using CFX. The characteristics of the drag, lift, pitching moment influenced by the distance to sea bottom and the attack angle are studied. The result shows that the drag coefficient increases with the decrease of distance, while it increases with the increase of attack angle. There exists attraction force when UUV moves close to the sea bottom, and the attraction force increases with the decrease in distance. The lift coefficient increases with the increase in attack angle. The absolute value of the pitching moment coefficient increases with the decrease in distance and the increase in attack angle.

Bay breeze climatology at two sites along the Chesapeake bay from 1986-2010: Implications for surface ozone.

Science.gov (United States)

Stauffer, Ryan M; Thompson, Anne M

Hourly surface meteorological measurements were coupled with surface ozone (O 3 ) mixing ratio measurements at Hampton, Virginia and Baltimore, Maryland, two sites along the Chesapeake Bay in the Mid-Atlantic United States, to examine the behavior of surface O 3 during bay breeze events and quantify the impact of the bay breeze on local O 3 pollution. Analyses were performed for the months of May through September for the years 1986 to 2010. The years were split into three groups to account for increasingly stringent environmental regulations that reduced regional emissions of nitrogen oxides (NO x ): 1986-1994, 1995-2002, and 2003-2010. Each day in the 25-year record was marked either as a bay breeze day, a non-bay breeze day, or a rainy/cloudy day based on the meteorological data. Mean eight hour (8-h) averaged surface O 3 values during bay breeze events were 3 to 5 parts per billion by volume (ppbv) higher at Hampton and Baltimore than on non-bay breeze days in all year periods. Anomalies from mean surface O 3 were highest in the afternoon at both sites during bay breeze days in the 2003-2010 study period. In conjunction with an overall lowering of baseline O 3 after the 1995-2002 period, the percentage of total exceedances of the Environmental Protection Agency (EPA) 75 ppbv 8-h O 3 standard that occurred on bay breeze days increased at Hampton for 2003-2010, while remaining steady at Baltimore. These results suggest that bay breeze circulations are becoming more important to causing exceedance events at particular sites in the region, and support the hypothesis of Martins et al. (2012) that highly localized meteorology increasingly drives air quality events at Hampton.

Recent studies on wind seas and swells in the Indian Ocean: A review

Digital Repository Service at National Institute of Oceanography (India)

Vethamony, P.; Rashmi, R.; Samiksha, S.V.; Aboobacker, V.M.

resolution winds are necessary to understand the effect of land-sea breeze on wind-sea generation in the coastal regions We have used atmospheric models such as MM5 and WRF to generate fine resolution winds, and the same will be used in wave models...

Surface current dynamics under sea breeze conditions observed by simultaneous HF radar, ADCP and drifter measurements

Science.gov (United States)

Sentchev, Alexei; Forget, Philippe; Fraunié, Philippe

2017-04-01

Ocean surface boundary layer dynamics off the southern coast of France in the NW Mediterranean is investigated by using velocity observations by high-frequency (HF) radars, surface drifting buoys and a downward-looking drifting acoustic Doppler current profiler (ADCP). The analysis confirms that velocities measured by HF radars correspond to those observed by an ADCP at the effective depth z f = k -1, where k is wavenumber of the radio wave emitted by the radar. The radials provided by the radars were in a very good agreement with in situ measurements, with the relative errors of 1 and 9 % and root mean square (RMS) differences of 0.02 and 0.04 m/s for monostatic and bistatic radar, respectively. The total radar-based velocities appeared to be slightly underestimated in magnitude and somewhat biased in direction. At the end of the survey period, the difference in the surface current direction, based on HF radar and ADCP data, attained 10°. It was demonstrated that the surface boundary layer dynamics cannot be reconstructed successfully without taking into the account velocity variation with depth. A significant misalignment of ˜30° caused by the sea breeze was documented between the HF radar (HFR-derived) surface current and the background current. It was also found that the ocean response to a moderate wind forcing was confined to the 4-m-thick upper layer. The respective Ekman current attained the maximum value of 0.15 m/s, and the current rotation was found to be lagging the wind by approximately 40 min, with the current vector direction being 15-20° to the left of the wind. The range of velocity variability due to wind forcing was found comparable with the magnitude of the background current variability.

Air pollution studies in Chicago considering lake breeze events and land use

Science.gov (United States)

Schmeling, M.; Treering, D. J.

2008-12-01

Trace elemental, ionic species and reactive trace gases were monitored and measured in Chicago air during the summers of 2002 to 2005. Weather data obtained for the same time periods provided information about major wind patterns. Sampling times and duration were selected to coincide with lake breezes, which occur with highest frequency in summer. Lake breezes were observed between 14 and 47 percent of total collection days per summer and appeared to be more frequent in the cooler summers of 2003 and 2004. Depending on the predominant wind direction on the day before, pollutants increased briefly during a lake breeze event. On days without the occurrence of a lake breeze, it was found that the highest concentrations of pollutants were transported by southerly wind currents. Some major sources, such as brick and cement manufacturing, steel industry and heavy road traffic, lay in the path of this wind current. Chicago area land use and transportation maps were analyzed using a Geographic Information System (GIS) to identify major industrial complexes, intermodal terminals, highways and railroads. We also included demographic information in the GIS maps to analyze whether certain population groups are disproportionally exposed to air pollution. Our results will not only be interesting for the science community, but also to policy makers when considering air pollutant exposure and are expected to inform decisions regarding air pollution policy in the future.

A breeze-driven current on sloped littoral waters

Science.gov (United States)

Tohidi, A.; Jamali, M.

2017-12-01

Various natural phenomena, e. g. uniform/non-uniform solar radiation and diurnal cycles, affect water circulation patterns through aquatic canopies, that is (usually shallow) shorelines of the rivers, lakes, and lagoons. Amongst these factors is vegetation that, plays a crucial role in conserving and dispersing the nutrients, oxygen, temperature, and generally regulating the life and interactions of organisms with each other (ecology) in aquatic canopies. So far, however, very little attention has been paid to the effects of very low, breeze-like, winds over the water surface in these vegetated regions. In this exploratory study, the evolution of a breeze-driven gravity current traveling up the slope towards the shorelines is shown, experimentally. The flow is characterized using Particle Image Velocimetry (PIV) technique. In addition, a detailed dimensional analysis of the parameter space of the phenomenon is conducted. The results strongly corroborate the experimental observations.

Mesoscale modeling of smoke transport over the Southeast Asian Maritime Continent: Interplay of sea breeze, trade wind, typhoon, and topography

Science.gov (United States)

Wang, Jun; Ge, Cui; Yang, Zhifeng; Hyer, Edward J.; Reid, Jeffrey S.; Chew, Boon-Ning; Mahmud, Mastura; Zhang, Yongxin; Zhang, Meigen

2013-03-01

The online-coupled Weather Research and Forecasting model with Chemistry (WRFchem) is used to simulate the transport of smoke particles over the Southeast Asian Maritime Continent during September-October 2006. In this period, dry conditions associated with the moderate El Niño event caused the largest regional biomass burning outbreak since 1997. Smoke emission in WRFchem is specified according to the Fire Locating and Modeling of Burning Emissions (FLAMBE) database derived from Moderate Resolution Imaging Spectroradiometer (MODIS) fire products. The modeled smoke transport pathway is found to be consistent with the MODIS true color images and measured mass concentration of surface PM10 (particulate matter with diameter less than 10 μm). The interplay of sea/land breezes, typhoons and storms over the subtropical western Pacific Ocean, trade winds, and topographic effects, can be clearly seen in the model simulation. The most severe smoke events in 1-5 October 2006 are found to be associated with the meteorological responses to the typhoon Xangsane (#18) over the western subtropical Pacific Ocean, which moved smoke from Sumatra eastward in the lower troposphere (below 700 hPa), forming smoke layers mixed with and above the boundary layer clouds over Borneo. In contrast, the second largest week-long smoke transport event of 15-18 October 2006 was associated with the seasonal monsoonal transition period, during which smoke plumes were wide spread over the 5°S-5°N zone as a result of (a) the near surface divergence coupled with the 700 hPa bifurcation of wind (flowing both to the west and to the east), and (b) the near-surface southeasterly and easterly winds along the equator transporting smoke from Borneo to Sumatra and Peninsular Malaysia. Analysis of data from the Cloud-Aerosol Lidar with Orthogonal Polarisation (CALIOP) shows that smoke particles in October 2006 were primarily located within 3.5 km above the surface. Smoke particles contributed roughly half

78 FR 62300 - Prairie Breeze Wind Energy LLC; Supplemental Notice That Initial Market-Based Rate Filing...

Science.gov (United States)

2013-10-15

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER14-25-000] Prairie Breeze Wind Energy LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request for Blanket... Breeze Wind Energy LLC's application for market-based rate authority, with an accompanying rate schedule...

Breeze Gravity Current in a Uniform Flow of Air

Directory of Open Access Journals (Sweden)

M.V. Shokurov

2017-02-01

Full Text Available Breeze circulation is often observed nearby the water basin coasts and usually accompanied by a background synoptic wind. One of the basic dynamically important components of the breeze circulation is gravity current. In the present paper the latter is used as the breeze simplified model. The theory of interaction of gravity current and a uniform synoptic wind are developed. The gravity current in the domain of infinite height in a stationary environment and environment with background flow was considered. To solve this problem the law of conservation of mass and universal property of the Froude number was used, which is true in the steady state. It is shown that increase of a tail-wind is followed by growth of the gravity current velocity and decrease of its height. The opposite situation is observed at increase of a head wind: the current velocity reduces and its height increases. Using a Taylor series expansion for small values of the background flow velocity a linear dependence of gravity current velocity on background flow velocity can be obtained. The factor determining the slope of the velocity of gravity current propagation on the background wind speed, which is equal 2/3, is a universal constant. The theory explains the results of numerical simulation previously obtained by numerous authors. A physical interpretation of dependence of the height and velocity of the gravity current on the background flow velocity is presented.

Impact of Bay-Breeze Circulations on Surface Air Quality and Boundary Layer Export

Science.gov (United States)

Loughner, Christopher P.; Tzortziou, Maria; Follette-Cook, Melanie; Pickering, Kenneth E.; Goldberg, Daniel; Satam, Chinmay; Weinheimer, Andrew; Crawford, James H.; Knapp, David J.; Montzka, Denise D.;

Impact of sea breeze on the wind-seas off Goa, west coast of India

Digital Repository Service at National Institute of Oceanography (India)

Neetu, S.; Shetye, S.R.; Chandramohan, P.

, and fitted a theoretical equilibrium spectrum. The theoretical spectrum chosen was the TMA spectrum (Bouws et al 1985), formulated as an extension of the JONSWAP spec- trum (Hasselmann et al 1973) for wind-generated seas in a finite water depth. The depth... with the dispersion relationship for waves in finite water depth. The TMA spectrum that could provide the best fit for the sea-related observed spectrum off Goa, was determined by choosing the equivalent fetch and wind speed that minimized the sum of squares...

Examining the eastern Amazon Basin breeze circulations, channeling and boundary layer properties using altitude controlled meteorological balloons

Science.gov (United States)

Fitzjarrald, D. R.; Voss, P. B.; Silva, R. D.; Callahan, S.; Dewald, A.; do Vale, R. S.

2017-12-01

During the period August 24-28, 2016, in a delayed component the GO-Amazon Project, we launched nine altitude-controlled free balloons (CMET). Smaller than typical rawinsondes, CMET are equipped with altitude control, global communication via Iridium satellite, and aspirated sensors. The aims of our effort were to examine the interactions among convective boundary layer and dual river breeze circulations near the confluence of the Tapajos and Amazon Rivers in the eastern Basin. The week-long field campaign was timed to examine the reestablishment of the breeze circulations shortly after the passage of a strong instability line on August 22. Nine CMET were launched at the Curua-Una hydroelectric dam (2.8S; 54.3W), timed to encounter the Tapajos river breeze front by late afternoon. Soundings were made to establish the thickness of interface between the easterly trade and westerly Tapajos breeze circulation. Careful use of sounding strategies allowed these free balloons to track along the northerly channeled flow in the lowest 300 m above the River. Following the river encounter, balloons tracked to the west, sounding to describe the diurnal course of boundary layer in the forest west of the Tapajos River. The longest flight traveled more than 770 km over three days and twice rested overnight in the rain forest canopy. Ancillary data from surface climate and flux stations as well as the Santarem radiosonde, satellite images will be used to illustrate how the breeze circulations are seen near the surface and how they were disrupted by larger-scale events. Comparisons with HYSPLIT trajectories will illustrate how sensitive real trajectories are to the refraction that the encounter with the breeze effects.

The monsoon system: Land–sea breeze or the ITCZ?

Indian Academy of Sciences (India)

Sulochana Gadgil

2018-01-27

Jan 27, 2018 ... ocean contrast is one of the main drivers of the monsoon rainfall, in the 5th Assessment Report of the Inter-governmental Panel on Climate Change. (IPCC Climate Change 2013), the likely enhance- ment of monsoon rainfall has been attributed to increased land–sea contrast, and more abundant.

Thermal Internal Boundary Layer characteristics at a tropical coastal ...

Indian Academy of Sciences (India)

R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

reduction in the momentum fluxes gives rise to decrease in the turbulence intensity. Updraft in the sea breeze front ... upper level synoptic flow and the sea breeze. Ver- tical velocity ...... the sea breezes over south Florida; Mon. Weather Rev.

Severe Weather Guide - Mediterranean Ports. 4. Augusta Bay

Science.gov (United States)

1988-03-01

the year. The track o-f strong extratropical storms has moved northward and poses little tiireat to Augusta Bay. Sea breezes are daily occurrences...as temperatures, begin to moderate. Extratropi cal systems begin to transit Europe as the storm track moves southward in advance of the winter...SUB-GROUP 18. SUBJECT TERMS {Continue on reverse if necessary and identify by block number) Storm haven Mediterranean meteorology Augusta Bay

Investigation of local meteorological events and their relationship with ozone and aerosols during an ESCOMPTE photochemical episode

Directory of Open Access Journals (Sweden)

P. Augustin

2006-11-01

Full Text Available The international ESCOMPTE campaign, which took place in summer 2001 in the most highly polluted French region, was devoted to validate air pollution prediction models. Surface and remote sensing instruments (Lidar, Radar and Sodar were deployed over the Marseille area, along the Mediterranean coast, in order to investigate the fine structure of the sea-breeze circulation and its relationship with the pollutant concentrations. The geographical situation of the Marseille region combines a complex coastline and relief which both lead to a peculiar behaviour of the sea-breeze circulation. Several local sea breezes, perpendicular to the nearest coastline, settled in during the morning. In the afternoons, when the thermal gradient between the continental and marine surface grows up, a southerly or a westerly sea breeze may dominate. Their respective importance is then a function of time, space and altitude. Furthermore, an oscillation of the westerly sea breeze with a period of about 3 h is also highlighted. We show that these dynamical characteristics have profound influences on the atmospheric boundary-layer (ABL development and on pollutant concentrations. In fact, the direction and intensity of the sea-breeze determine the route and the transit time of the stable marine air flow over the continental surface. Thus, the ABL depth may exhibit several collapses correlated with the westerly sea-breeze pulsation. The ozone and aerosol concentrations are also related to the dynamical features. In the suburbs and parts of the city under pulsed sea breezes, a higher ABL depth and higher ozone concentrations are observed. In the city centre, this relationship between pulsed sea-breeze intensity and ozone concentration is different, emphasising the importance of the transit time and also the build-up of pollutants in the marine air mass along the route. Finally, the variations of aerosol concentration are also described according to the breeze direction.

Investigation of local meteorological events and their relationship with ozone and aerosols during an ESCOMPTE photochemical episode

Science.gov (United States)

Augustin, P.; Delbarre, H.; Lohou, F.; Campistron, B.; Puygrenier, V.; Cachier, H.; Lombardo, T.

2006-11-01

The international ESCOMPTE campaign, which took place in summer 2001 in the most highly polluted French region, was devoted to validate air pollution prediction models. Surface and remote sensing instruments (Lidar, Radar and Sodar) were deployed over the Marseille area, along the Mediterranean coast, in order to investigate the fine structure of the sea-breeze circulation and its relationship with the pollutant concentrations. The geographical situation of the Marseille region combines a complex coastline and relief which both lead to a peculiar behaviour of the sea-breeze circulation. Several local sea breezes, perpendicular to the nearest coastline, settled in during the morning. In the afternoons, when the thermal gradient between the continental and marine surface grows up, a southerly or a westerly sea breeze may dominate. Their respective importance is then a function of time, space and altitude. Furthermore, an oscillation of the westerly sea breeze with a period of about 3 h is also highlighted. We show that these dynamical characteristics have profound influences on the atmospheric boundary-layer (ABL) development and on pollutant concentrations. In fact, the direction and intensity of the sea-breeze determine the route and the transit time of the stable marine air flow over the continental surface. Thus, the ABL depth may exhibit several collapses correlated with the westerly sea-breeze pulsation. The ozone and aerosol concentrations are also related to the dynamical features. In the suburbs and parts of the city under pulsed sea breezes, a higher ABL depth and higher ozone concentrations are observed. In the city centre, this relationship between pulsed sea-breeze intensity and ozone concentration is different, emphasising the importance of the transit time and also the build-up of pollutants in the marine air mass along the route. Finally, the variations of aerosol concentration are also described according to the breeze direction.

Investigation of local meteorological events and their relationship with ozone and aerosols during an ESCOMPTE photochemical episode

Directory of Open Access Journals (Sweden)

P. Augustin

2006-11-01

Full Text Available The international ESCOMPTE campaign, which took place in summer 2001 in the most highly polluted French region, was devoted to validate air pollution prediction models. Surface and remote sensing instruments (Lidar, Radar and Sodar were deployed over the Marseille area, along the Mediterranean coast, in order to investigate the fine structure of the sea-breeze circulation and its relationship with the pollutant concentrations.

The geographical situation of the Marseille region combines a complex coastline and relief which both lead to a peculiar behaviour of the sea-breeze circulation. Several local sea breezes, perpendicular to the nearest coastline, settled in during the morning. In the afternoons, when the thermal gradient between the continental and marine surface grows up, a southerly or a westerly sea breeze may dominate. Their respective importance is then a function of time, space and altitude. Furthermore, an oscillation of the westerly sea breeze with a period of about 3 h is also highlighted.

We show that these dynamical characteristics have profound influences on the atmospheric boundary-layer (ABL development and on pollutant concentrations. In fact, the direction and intensity of the sea-breeze determine the route and the transit time of the stable marine air flow over the continental surface. Thus, the ABL depth may exhibit several collapses correlated with the westerly sea-breeze pulsation. The ozone and aerosol concentrations are also related to the dynamical features. In the suburbs and parts of the city under pulsed sea breezes, a higher ABL depth and higher ozone concentrations are observed. In the city centre, this relationship between pulsed sea-breeze intensity and ozone concentration is different, emphasising the importance of the transit time and also the build-up of pollutants in the marine air mass along the route. Finally, the variations of aerosol concentration are also described according to the

Reducibility mill scale industrial waste via coke breeze at 850-950ºC

Directory of Open Access Journals (Sweden)

Gaballah N.M.

2015-01-01

Full Text Available Mill scale is a very attractive industrial waste due to its elevated iron content (about = 69.33% Fe besides being suiTab. for direct recycling to the blast furnace via sintering plant. In this paper the characteristics of raw materials and the briquettes produced from this mill scale were studied by different methods of analyses. The produced briquettes were reduced with different amounts of coke breeze at varying temperatures, and the reduction kinetics was determined. The activation energy of this reaction ≈ 61.5 kJ/mole for reduction of mill scale with coke breeze in the form of briquettes with 2% molasses where the chemical reaction interface model is applicable.

Wave transformation and attenuation along the west coast of India: Measurements and numerical simulations

Digital Repository Service at National Institute of Oceanography (India)

Aboobacker, V.M.; Vethamony, P.; Samiksha, S.V.; Rashmi, R.; Jyoti, K.

] “Impact of sea-breeze on wind-seas off Goa, west coast of India,” Journal of Earth System Science,115(2), 229-234. Rani, S.I., Radhika, R., Subrahamanyam, D.B., Denny, P.A., Kunhikrishnan, P.K. [2010] “Characterization of sea/land breeze circulation...., Praveena, K. [2001] “Study of sea breeze and land breeze along the west coast of Indian sub-continent over the latitude range 15°N to 8°N during INDOEX IFP-99 (SK-141) cruise,”Current Science, 80, 85-88. Sullivan, P.P., Edson. J.B., Hristov, T., Mc...

Mesoscale energetics and flows induced by sea-land and mountain-valley contrasts

Directory of Open Access Journals (Sweden)

S. Federico

2000-02-01

Full Text Available We study the relative importance of sea-land and mountain-valley thermal contrasts in determining the development of thermally forced mesoscale circulations (TFMCs over a mountainous peninsula. We first analyse the energetics of the problem, and using this theory, we interprete the numerical simulations over Calabria, a mountainous peninsula in southern Italy. The CSU 3-D nonlinear numerical model is utilised to simulate the dynamics and the thermodynamics of the atmospheric fields over Calabria. Results show the importance of orography in determining the pattern of the flow and the local climate in a region as complex as Calabria. Analysis of the results shows that the energetics due to the sea-land interactions are more efficient when the peninsula is flat. The importance of the energy due to the sea-land decreases as the mountain height of the peninsula increases. The energy stored over the mountain gains in importance, untill it is released by the readjustment of the warm mountain air as it prevails over the energy released by the inland penetration of the sea breeze front. For instance, our results show that over a peninsula 100 km wide the energy over the mountain and the energy in the sea-land contrast are of the same order when the height of the mountain is about 700 m, for a 1500 m convective boundary layer (CBL depth. Over the Calabrian peninsula, the energy released by the hot air in the CBL of the mountain prevails over the energy released by the inland penetration of the sea air. Calabria is about 1500 m high and about 50 km wide, and the CBL is of the order of 1500 m. The energy over the mountain is about four time larger than the energy contained in the sea-land contrast. Furthermore, the energetics increase with the patch width of the peninsula, and when its half width is much less than the Rossby radius, the MAPE of the sea breeze is negligible. When its half width is much larger than the Rossby radius, the breezes from the two

Reducibility study of Rossetta ilmenite ore briquettes and powder with coke breeze at 800-1100°C

Directory of Open Access Journals (Sweden)

Abd el Gawad Hala H.

2013-01-01

Full Text Available Ilmenite ore fine and coke breeze as reduced material were briquetted with different amounts of organic materials such as molasses or pitch were studied in this investigation. The produced briquettes at reasonable condition were reduced in nitrogen atmosphere at temperature range 800 - 1100oC to determine the factors controlling the reduction and to determine the controlling mechanism. Also ilmenite ore fine with coke breeze were reduced at the same temperature range in nitrogen atmosphere without briquetting process, for the sake of comparison.

A Simple Technique for Creating Regional Composites of Sea Surface Temperature from MODIS for Use in Operational Mesoscale NWP

Science.gov (United States)

Knievel, Jason C.; Rife, Daran L.; Grim, Joseph A.; Hahmann, Andrea N.; Hacker, Joshua P.; Ge, Ming; Fisher, Henry H.

2010-01-01

This paper describes a simple technique for creating regional, high-resolution, daytime and nighttime composites of sea surface temperature (SST) for use in operational numerical weather prediction (NWP). The composites are based on observations from NASA s Moderate Resolution Imaging Spectroradiometer (MODIS) aboard Aqua and Terra. The data used typically are available nearly in real time, are applicable anywhere on the globe, and are capable of roughly representing the diurnal cycle in SST. The composites resolution is much higher than that of many other standard SST products used for operational NWP, including the low- and high-resolution Real-Time Global (RTG) analyses. The difference in resolution is key because several studies have shown that highly resolved SSTs are important for driving the air sea interactions that shape patterns of static stability, vertical and horizontal wind shear, and divergence in the planetary boundary layer. The MODIS-based composites are compared to in situ observations from buoys and other platforms operated by the National Data Buoy Center (NDBC) off the coasts of New England, the mid-Atlantic, and Florida. Mean differences, mean absolute differences, and root-mean-square differences between the composites and the NDBC observations are all within tenths of a degree of those calculated between RTG analyses and the NDBC observations. This is true whether or not one accounts for the mean offset between the skin temperatures of the MODIS dataset and the bulk temperatures of the NDBC observations and RTG analyses. Near the coast, the MODIS-based composites tend to agree more with NDBC observations than do the RTG analyses. The opposite is true away from the coast. All of these differences in point-wise comparisons among the SST datasets are small compared to the 61.08C accuracy of the NDBC SST sensors. Because skin-temperature variations from land to water so strongly affect the development and life cycle of the sea breeze, this

Wind effect on currents in a thin surface layer of coastal waters faced open-sea

International Nuclear Information System (INIS)

Nakano, Masanao; Isozaki, Hisaaki; Isozaki, Tokuju; Nemoto, Masashi; Hasunuma, Keiichi; Kitamura, Takashi

2009-01-01

Two-years of continuous observation of wind and current were carried out to investigate the relationship between them in the coastal waters off Tokai-mura, Ibaraki prefecture. Three instruments to measure the current were set in a thin surface layer of 3 m above the strong pycnocline, which is a common feature in coastal waters. Both of the power spectra of wind and currents showed very similar features, an outstanding high peak at 24-hour period and a range of high peaks longer than several-days period. The long term variation of the wind field always contained north-wind component, which contributed to forming the southward current along the shore throughout the year. A high correlation coefficient (0.64) was obtained between the wind and the current at a depth of 0.5 m on the basis of the two-year observation. Harmonic analysis revealed that an outstanding current with 24-hour period was the S 1 component (meteorological tide), and was driven by land and sea breezes. These breezes also contained solar tidal components such as K 1 , P 1 and S 2 . These wind components added their own wind driven currents on the original tidal currents. This meant that land and sea breezes generated wind driven currents with solar tidal periods which behaved like astronomical tidal currents. As result, coastal currents contained pseudo tidal currents which behaved like astronomical tidal currents. (author)

Local and Regional Winds: Their Names and Attributes,

Science.gov (United States)

1982-03-30

bryza morska ("sea breeze"), but it is weaker than it, blowing across the surface of a large lake toward the shore during the daylight hours, mainly...city toward its center, with a simultaneous increase in convection movements above it. Bryza morska ("sea breeze") -- a wind blowing from off the sea...during the summer season for several days during the month; the bryza morska ("sea breeze") may be felt, depending on its intensity, up to distances of

Investigating erosion of building materials used in an installation for pneumatic transport of coke breeze and coal

Energy Technology Data Exchange (ETDEWEB)

Bandrowski, J.; Kot-Borkowska, Z.; Misztal, M.; Raczek, J.; Kaczmarzyk, G.

1980-09-01

This article investigates the influence of the following factors on erosion of building material used in pneumatic transport of coal and coke breeze: intensity of coal or coke breeze flow within the range of 47 to 120 kg/h for coke and 99 to 165 kg/h for coal; speed of solid material particles within the range 3.71 to 7.97 m/s for coke, and 3.30 to 7.58 m/s for coal; duration of the experiments 0.5 to 1.5 h for coke and 2.0 to 5.0 for coal; angle of inclination of the sample of building material 30 to 60 degrees for both coal and coke breeze. Three types of construction material used in pneumatic transport were tested: steel, concrete and chamotte bricks. Investigations show that concrete is characterized by the highest erosion, chamotte bricks by medium erosion and steel by the lowest erosion. As a result of mathematical processing of experimental data, empirical models of erosion of the three materials are constructed. (7 refs.)

Influence of winds on temporally varying short and long period gravity waves in the near shore regions of the eastern Arabian Sea

Digital Repository Service at National Institute of Oceanography (India)

Glejin, J.; SanilKumar, V.; Nair, T.M.B.; Singh, J.

pro- vided by the NOAA-CIRES (Cooperative Institute for Re- search in the Environmental Sciences) Climate Diagnostics Center in Boulder, Colorado (http://www.cdc.noaa.gov/). To determine the sea/land breeze system at Ratnagiri during the study period...

Variability in the air–sea interaction patterns and timescales within the south-eastern Bay of Biscay, as observed by HF radar data

Directory of Open Access Journals (Sweden)

A. Fontán

2013-04-01

Full Text Available Two high-frequency (HF radar stations were installed on the coast of the south-eastern Bay of Biscay in 2009, providing high spatial and temporal resolution and large spatial coverage of currents in the area for the first time. This has made it possible to quantitatively assess the air–sea interaction patterns and timescales for the period 2009–2010. The analysis was conducted using the Barnett–Preisendorfer approach to canonical correlation analysis (CCA of reanalysis surface winds and HF radar-derived surface currents. The CCA yields two canonical patterns: the first wind–current interaction pattern corresponds to the classical Ekman drift at the sea surface, whilst the second describes an anticyclonic/cyclonic surface circulation. The results obtained demonstrate that local winds play an important role in driving the upper water circulation. The wind–current interaction timescales are mainly related to diurnal breezes and synoptic variability. In particular, the breezes force diurnal currents in waters of the continental shelf and slope of the south-eastern Bay. It is concluded that the breezes may force diurnal currents over considerably wider areas than that covered by the HF radar, considering that the northern and southern continental shelves of the Bay exhibit stronger diurnal than annual wind amplitudes.

Co-existence of wind seas and swells along the west coast of India during non-monsoon season

Digital Repository Service at National Institute of Oceanography (India)

Rashmi, R.; Aboobacker, V.M.; Vethamony, P; John, M.P

-dimensional significant wind sea heightH ∗S and peak wind sea period T ∗P have been calculated (Fig. 9). The best fit between log (H ∗Sws) and log (T ∗Pws) has been es- timated and resolved as follows: Fig. 7. (a), (b), (c), (d), (e) and (f) are wave energy spectrum, wave... of shallow water waves along Indian coast, J. Coastl. Res., 19, 1052–1065, 2003. Neetu, S., Shetye, S., and Chandramohan, P.: Impact of sea-breeze on wind seas off Goa, west coast of India, J. Earth Sys. Sci., 115, 229–234, 2006. Peterson, E. W. and Hennessey...

Journal of Earth System Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

... seas spectra very well when the sea-breeze was active and the fetch corresponding to equilibrium spectrum was found to be 77 ± 43 km during such occasions. We emphasize on the diurnal cycle of sea-breeze-related sea off the coast of Goa and write an equation for the energy of the seas as a function of the local wind.

Sea-town interactions over Marseille: 3D urban boundary layer and thermodynamic fields near the surface

Science.gov (United States)

Lemonsu, A.; Pigeon, G.; Masson, V.; Moppert, C.

2006-02-01

3D numerical simulations with the Meso-NH atmospheric model including the Town Energy Balance urban parameterization, are conducted over the south-east of France and the one million inhabitants city of Marseille in the frameworks of the ESCOMPTE-UBL program. The geographic situation of the area is relatively complex, because of the proximity of the Mediterranean Sea and the presence of numerous massifs, inducing complex meteorological flows. The present work is focused on six days of the campaign, characterized by the development of strong summer sea-breeze circulations. A complete evaluation of the model is initially realized at both regional- and city-scales, by using the large available database. The regional evaluation shows a good behavior of the model, during the six days of simulation, either for the parameters near the surface or for the vertical profiles describing the structure of the atmosphere. The urban-scale evaluation indicates that the fine structure of the horizontal fields of air temperature above the city is correctly simulated by the model. A specific attention is then pointed to the 250-m horizontal resolution outputs, focused on the Marseille area, for two days of the campaign. From the study of the vertical structure of the Urban Boundary Layer and the thermodynamic fields near the surface, one underscores the important differences due to the regional and local flows, and the complex interactions that occur between the urban effects and the effects of sea breezes.

The characteristics of local atmospheric circulation around the Wolsung NPP in Korea

International Nuclear Information System (INIS)

Lee, G.B.; Lee, M.C.; Song, Y.I.

1998-01-01

The transport of air pollutants in coastal regions has been known to be strongly affected by the mesoscale atmospheric circulations such as sea-land breezes. These mesoscale atmospheric circulations depend on synoptic weather conditions. In this study, a three-dimensional sea-land breeze model was developed to evaluate the effects of the sea and land breezes on the atmospheric dispersion of radioactive materials released from nuclear power plants in Korea. In the model, the hydrostatic primitive equations in the terrain-following coordinate system were used. The mesoscale atmospheric circulation simulation were carried out under various synoptic weather conditions for all seasons around the Wolsung nuclear power plant site

Influence of Indian summer monsoon variability on the surface waves in the coastal regions of eastern Arabian Sea

Digital Repository Service at National Institute of Oceanography (India)

SanilKumar, V.; Jesbin, G.

–885, 2016 www.ann-geophys.net/34/871/2016/ doi:10.5194/angeo-34-871-2016 © Author(s) 2016. CC Attribution 3.0 License. Influence of Indian summer monsoon variability on the surface waves in the coastal regions of eastern Arabian Sea V. Sanil Kumar and Jesbin... of the period. The annual average value is ∼ 1.5 m (Anoop et al., 2015). During the non-monsoon period, the land and sea breeze has a signif- icant influence on the wave climate of eastern AS (Glejin Ann. Geophys., 34, 871–885, 2016 www.ann-geophys.net/34...

Ozone pollution around a coastal region of South China Sea: interaction between marine and continental air

Science.gov (United States)

Wang, Hao; Lyu, Xiaopu; Guo, Hai; Wang, Yu; Zou, Shichun; Ling, Zhenhao; Wang, Xinming; Jiang, Fei; Zeren, Yangzong; Pan, Wenzhuo; Huang, Xiaobo; Shen, Jin

2018-03-01

Marine atmosphere is usually considered to be a clean environment, but this study indicates that the near-coast waters of the South China Sea (SCS) suffer from even worse air quality than coastal cities. The analyses were based on concurrent field measurements of target air pollutants and meteorological parameters conducted at a suburban site (Tung Chung, TC) and a nearby marine site (Wan Shan, WS) from August to November 2013. The observations showed that the levels of primary air pollutants were significantly lower at WS than those at TC, while the ozone (O3) value was greater at WS. Higher O3 levels at WS were attributed to the weaker NO titration and higher O3 production rate because of stronger oxidative capacity of the atmosphere. However, O3 episodes were concurrently observed at both sites under certain meteorological conditions, such as tropical cyclones, continental anticyclones and sea-land breezes (SLBs). Driven by these synoptic systems and mesoscale recirculations, the interaction between continental and marine air masses profoundly changed the atmospheric composition and subsequently influenced the formation and redistribution of O3 in the coastal areas. When continental air intruded into marine atmosphere, the O3 pollution was magnified over the SCS, and the elevated O3 ( > 100 ppbv) could overspread the sea boundary layer ˜ 8 times the area of Hong Kong. In some cases, the exaggerated O3 pollution over the SCS was recirculated to the coastal inshore by sea breeze, leading to aggravated O3 pollution in coastal cities. The findings are applicable to similar mesoscale environments around the world where the maritime atmosphere is potentially influenced by severe continental air pollution.

Advanced SAR Interferometric Analysis to Support Geomorphological Interpretation of Slow-Moving Coastal Landslides (Malta, Mediterranean Sea

Directory of Open Access Journals (Sweden)

Matteo Mantovani

2016-05-01

Full Text Available An advanced SAR interferometric analysis has been combined with a methodology for the automatic classification of radar reflectors phase histories to interpret slope-failure kinematics and trend of displacements of slow-moving landslides. To accomplish this goal, the large dataset of radar images, acquired in more than 20 years by the two European Space Agency (ESA missions ERS-1/2 and ENVISAT, was exploited. The analysis was performed over the northern sector of Island of Malta (central Mediterranean Sea, where extensive landslides occur. The study was assisted by field surveys and with the analysis of existing thematic maps and landslide inventories. The outcomes allowed definition of a model capable of describing the geomorphological evolution of slow-moving landslides, providing a key for interpreting such phenomena that, due to their slowness, are usually scarcely investigated.

A multi-stage oil-water-separating process design for the sea oil spill recovery robot

Science.gov (United States)

Zhang, Min-ge; Wu, Jian-guo; Lin, Xinhua; Wang, Xiao-ming

2018-03-01

Oil spill have the most common pollution to the marine ecological environment. In the late stage of physical method recovery, because of the thin oil and the strong sea breeze, the recovery vessels has low efficiency and high energy consumption. This paper develops a multi-stage oil-water-separating process carried by the sea oil spill recovery robot in severe conditions. This design consists of three separation process, among which both the first and third process adopt corrugated sheets horizontal oil-water separator, while the second is hydraulic rotary breaker. This design also equiptment with rectifier and cyclone separator and other important components. This process has high flexibility and high recovery efficiency. The implement effect is significant.

Gathering by the Red Sea highlights links between environment and epigenetics

KAUST Repository

Li, Mo

2017-06-06

The number of conferences on epigenetics has been increasing in the past decade, underscoring the impact of the field on a variety of areas in biology and medicine. However, the mechanistic role of the epigenome in adaptation and inheritance, and how the environment may impinge on epigenetic control, are topics of growing debate. Those themes were the focus of the inaugural international King Abdullah University of Science and Technology (KAUST) Research Conference on Environmental Epigenetics in Saudi Arabia, where more than 100 participants from 19 countries enjoyed vibrant scientific discussions and a pleasant February breeze from the Red Sea.

Remote sensing of PBL meteorology and air quality: the outcome of the ESCOMPTE experiment

Energy Technology Data Exchange (ETDEWEB)

Drobinski, P [Institut Pierre Simon Laplace/Laboratoire de Meteorologie Dynamique, Ecole Polytechnique, Palaiseau (France)], E-mail: philippe.drobinski@lmd.polytechnique.fr

2008-05-01

In the French Mediterranean basin, the large city of Marseille and its industrialized suburbs (oil plants in the Fos-Berre area) are major pollutant sources which cause frequent and hazardous pollution episodes especially in summer when intense solar heating enhances the photochemical activity and when sea-breeze circulation redistributes pollutants further north in the countryside. This paper summarizes the findings of five years of research on the sea-breeze in southeastern France and related mesoscale transport and dilution of pollutants within the ESCOMPTE program held in June and July 2001 (field experiment to constraint models of atmospheric pollution and emissions transport), obtained thanks to a composite observing system and a combination of remote sensing and in situ systems which produced a wealth of data. Indeed, the combination of established and novel and highly sophisticated remote sensing instruments with conventional in situ measurements (dense surface network and radiosondes) allowed to capture previously unseen details of the fine structure of the sea breeze, allowed unprecedented insight into the structure of the sea breeze flow and its contribution to ozone redistribution and allowed the validation of ultrahigh-resolution numerical research and weather prediction models as well as chemistry transport models.

Remote sensing of PBL meteorology and air quality: the outcome of the ESCOMPTE experiment

International Nuclear Information System (INIS)

Drobinski, P

2008-01-01

In the French Mediterranean basin, the large city of Marseille and its industrialized suburbs (oil plants in the Fos-Berre area) are major pollutant sources which cause frequent and hazardous pollution episodes especially in summer when intense solar heating enhances the photochemical activity and when sea-breeze circulation redistributes pollutants further north in the countryside. This paper summarizes the findings of five years of research on the sea-breeze in southeastern France and related mesoscale transport and dilution of pollutants within the ESCOMPTE program held in June and July 2001 (field experiment to constraint models of atmospheric pollution and emissions transport), obtained thanks to a composite observing system and a combination of remote sensing and in situ systems which produced a wealth of data. Indeed, the combination of established and novel and highly sophisticated remote sensing instruments with conventional in situ measurements (dense surface network and radiosondes) allowed to capture previously unseen details of the fine structure of the sea breeze, allowed unprecedented insight into the structure of the sea breeze flow and its contribution to ozone redistribution and allowed the validation of ultrahigh-resolution numerical research and weather prediction models as well as chemistry transport models

Tides in three enclosed basins: the Baltic, Black and Caspian seas

Directory of Open Access Journals (Sweden)

Igor P Medvedev

2016-04-01

Full Text Available Tides are the main type of sea level variability in the world ocean. However, oceanic tides penetrate weakly, or do not penetrate at all, into enclosed basins such as the Baltic, Black and Caspian seas. Consequently, only directly forced tides are formed in these basins. Long observation time series (up to 123 years in the Baltic Sea and 38 years in the Black and Caspian seas at numerous stations were used to precisely estimate tidal constituents. High-resolution spectra revealed fine structure of discrete peaks at tidal frequencies. The diurnal radiational constituent S1 (1 cpd, apparently associated with breeze winds, was found to play an important role in general tidal dynamics in these seas. Harmonic analysis of tides for individual yearly series with consecutive vector averaging over the entire observational period was applied to estimate mean amplitudes and phases of tidal constituents. Our findings indicate that the formation and predominance of diurnal or semidiurnal tides in these seas appears to depend on the frequency-selective properties of the basins. Thus, in the Baltic Sea with fundamental modal period of about 27 h, diurnal tides dominate in the major eastern gulfs. In the Black Sea resonant amplification of semidiurnal tides is observed in the northwestern part. The predominance of semidiurnal tides in the Caspian Sea has also probably a resonant nature. Maximum tidal heights estimated for a 100-year period are 23 cm in the Baltic Sea, 18 cm in the Black Sea and 21 cm in the southern Caspian Sea.

Local scale atmospheric diffusion at a coastal site in the presence of breeze effect (phase III: data elaboration and model development). Volume 1

International Nuclear Information System (INIS)

Cagnetti, P.; Ferrara, V.; Pellegrini, A.

1985-01-01

The aim of this contract is the characterization, from the thermal and anemological point of view, of the lower layers of the atmosphere at a coastal site, affected by breeze circulation. Data are utilized to set up diffusion models for accidental releases of airborne materials, both of short and prolonged duration. Five inland meteorological campaigns, starting from Jan. 82 (Jan., Apr., Jul., Oct. 1982, Jan. 1983), have been carried out; an appropriate extension of the contract allowed the execution of two more campaigns in the open sea (Apr., Jul. 1983), utilizing the oceanographic ship ''Bannock'' kindly supplied by CNR. The analysis of the data showed the development of a well defined IBL during on-shore flow only in Spring and Summer, while an inversion layer was detectable aloft independently of the season (provided that an anticyclonic situation was present). According to those relevant features a simple diffusion model has been developed for short duration releases at local scale. Finally, the analysis and elaboration of the data, collected on site by a meteorological automatic station, allowed the extension of the model to prolonged releases

Extreme Vertical Gusts in the Atmospheric Boundary Layer

Science.gov (United States)

2015-07-01

Density Currents Sea breezes, thunderstorm outflows and cold fronts are all physically similar, but differ in size22. They cause lift as the cold air...the consideration of sea breezes and other density currents. Moreover, some thunderstorm outflows run far ahead of their parent storm and may even...substantially opaque to these frequencies means most of the infra- red radiation from water molecules to space is coming from the top of the cloud. On

A high-resolution assessment of wind and wave energy potentials in the Red Sea

KAUST Repository

Langodan, Sabique

2016-08-24

This study presents an assessment of the potential for harvesting wind and wave energy from the Red Sea based on an 18-year high-resolution regional atmospheric reanalysis recently generated using the Advanced Weather Research Forecasting model. This model was initialized with ERA-Interim global data and the Red Sea reanalysis was generated using a cyclic three-dimensional variational approach assimilating available data in the region. The wave hindcast was generated using WAVEWATCH III on a 5 km resolution grid, forced by the Red Sea reanalysis surface winds. The wind and wave products were validated against data from buoys, scatterometers and altimeters. Our analysis suggests that the distribution of wind and wave energy in the Red Sea is inhomogeneous and is concentrated in specific areas, characterized by various meteorological conditions including weather fronts, mesoscale vortices, land and sea breezes and mountain jets. A detailed analysis of wind and wave energy variation was performed at three hotspots representing the northern, central and southern parts of the Red Sea. Although there are potential sites for harvesting wind energy from the Red Sea, there are no potential sites for harvesting wave energy because wave energy in the Red Sea is not strong enough for currently available wave energy converters. Wave energy should not be completely ignored, however, at least from the perspective of hybrid wind-wave projects. (C) 2016 Elsevier Ltd. All rights reserved.

Investigating a high ozone episode in a rural mountain site

International Nuclear Information System (INIS)

Monteiro, A.; Strunk, A.; Carvalho, A.; Tchepel, O.; Miranda, A.I.; Borrego, C.; Saavedra, S.; Rodríguez, A.; Souto, J.; Casares, J.; Friese, E.; Elbern, H.

2012-01-01

A very high ozone episode with observed hourly values above 350 μg m −3 occurred in July 2005 at the Lamas d’Olo air quality monitoring station, located in a mountainous area in the north of Portugal. Aiming to identify the origin and formation of this ozone-rich episode, a statistical analysis and a modelling approach were applied. A cross-spectrum analysis in the frequency domain and a synoptic analysis of the meteorological and air quality time series were performed. In order to go further in this analysis, a numerical modelling approach was applied. The results indicate that the transport of ozone and its precursors is the main responsible for the high ozone concentrations. Together with the local mountain breeze and subsidence conditions, the sea-breeze circulation transporting pollutants from the coastal urban and industrialized areas that reach the site during late afternoon turn out to be the driving forces for the ozone peaks. - Highlights: ► A very high ozone episode occurred in a rural mountain site of Portugal in 2004. ► Data cross-spectrum analysis in the frequency domain was performed. ► A numerical modelling approach was also applied. ► The sea-breeze circulation transported pollutants from the urban and industrialized coast. ► The mountain breeze and subsidence conditions were also driving forces for ozone peaks. - The sea-breeze transporting pollutants from the coast, the mountain breeze and subsidence conditions, were the driving forces for the ozone episode occurred in a rural mountain site.

Variability of currents in front of the Venice Lagoon, Northern Adriatic Sea

Energy Technology Data Exchange (ETDEWEB)

Cosoli, S.; Gacic, M. [Istituto Nazionale di Oceanografia e di Geofisica Sperimentale - OGS, Sgonico (Trieste) (Italy); Mazzoldi, A. [Consiglio Nazionale delle Ricerche - ISMAR-CNR, Venice (Italy). Ist. di Scienze Marine

2008-07-01

Time scales and modes of variability of the flow in the water column in the Northern Adriatic Sea for late summer 2002 are described based on current record from a single bottom-mounted ADCP in the shallow-water area in front of the Venice Lagoon. The time averaged flow was directed 277 E (CCW), roughly aligned with the coastline, with typical magnitudes in the range 4-6 cm/s and a limited, not significant clockwise veering with depth. Tidal forcing was weak and mainly concentrated in the semidiurnal frequency band, with a barotropic (depth-independent) structure. On a diurnal time scale, tidal signal was biased by the sea-breeze regime and was characterized by a clockwise veering with depth according to the Ekman spiral. A complex EOF analysis on the velocity profile time series extracted two dominant spatial modes of variability, which explained more than 90% of the total variance in the current field. More than 78% of the total variance was accounted for by the first EOF mode, with a barotropic structure that contained the low-frequency components and the barotropic tidal signal at semidiurnal and diurnal frequencies. The second mode had a baroclinic structure with a zero-crossing at mid-depth, which was related with the response of the water column to the high-frequency wind-driven diurnal sea breeze variability. The response of low-passed non-tidal currents to local wind stress was fast and immediate, with negligible temporal lag up to mid-depth. Currents vectors were pointing to the right of wind stress, as expected from the surface Ekman veering, but with angles smaller than the expected ones. A time lag in the range 10 to 11 h was found below 8 m depth, with current vectors pointing to the left of wind stress and a counterclockwise veering towards the bottom. The delay was consistent with the frictional adjustment time scale describing the dynamics of a frictionally dominated flow in shallow water, thus suggesting the importance of bottom friction on the

Effect of urbanization in a coastal region on sea breeze and urban thermal environment

OpenAIRE

河原, 能久; 川又, 孝太郎; 玉井, 信行

1994-01-01

Effect of land use development in a coastal region on heat island phenomenon is studied numerically by an urban climate model that employs the k-e turbulence model and an eddy diffusivity model for the transport of momentum, temperature and moisture in the Eckman layer together with a heat balance model for the surface boundary layer and the soil layer. Numerical simulations are carried out for a simplified terrain which consists of sea and land. Changes in wind velocity, temperature and heat...

How to Move in a Jostling Crowd

Indian Academy of Sciences (India)

For people living in big cities it is an ordeal to walk in a bus stand or a railway station. They get stuck helplessly in a crowd. They are simply pushed around and all their efforts to move forward appear futile. Only the most energetic can wade through the constantly moving sea of people. How about the weaker ones?

The role of sea–land air thermal difference, shape of the coastline and sea surface temperature in the nocturnal offshore convection

Directory of Open Access Journals (Sweden)

Jordi Mazón

2013-01-01

Full Text Available Nocturnal precipitation cells and lines occur near the coastline in the whole Mediterranean basin in all seasons. The precipitation events are mainly located in areas where coastal mountain ranges and rivers enhance convergence though the interaction of nocturnal mesoscale and local flows (land breeze, katabatic and drainages winds with prevailing synoptic wind or with other mesoscale and local flows. The methodology used here to study this phenomenon consists of three stages. First, the Tropical Rainfall Measuring Mission (TRMM radar satellite database is used to detect nocturnal precipitation near the coastline, from 18 to 09 UTC. An event is included in the study if the 3 hours accumulated precipitation detected by TRMM is stationary near the coast, or has moved slightly onshore or offshore, and has lasted no more than six consecutive hours. Second, the NCEP reanalysis database is used to describe the synoptic conditions and to discard precipitation associated with synoptic events (large low pressure areas, dynamic polar fronts, or troughs, for example. In the final step by using the version 3 of the Weather Research Forecast model, we simulate and analyse some of the selected events to determine the role of the land–sea temperature differences, the curvature of the coastline and the sea surface temperature.The simulations confirm that the nocturnal precipitation studied in the Mediterranean basin near the coastline is formed from the interaction between relatively warm and wet sea-air with the cold air mass from drainage winds, as well as from the convergence of several drainage winds offshore. The mechanism is the same that is used to explain nocturnal precipitation in tropical areas.

Analysis of the wind rose at Itaorna, Brazil

International Nuclear Information System (INIS)

Nicolli, D.

1982-05-01

The Angra-I nuclear power plant is located on the southeastern coast of Brazil, in a bowl-shaped area with hills on three sides and a bay on the fourth side. To the north the surrounding hills rise to more than 600 meters, in the other directions they are lower. At the botton of this area a meteorological mast 50 meters high was installed. Hourly measurements of temperature differences between two levels, as well as wind speed and direction at 50m height were carried out. The wind speed and direction are analysed. The daily air flow at the site shows two distinct characteristics: one nocturnal flow from NE due to the combined effects of the trade and the katabatic winds and a diurnal flow from SW-W generated by the sea breezes. Throughout the year this 'normal' condition is disturbed by low pressure systems that move over the region. For about 10% of the time these weather systems account for the disturbed flow regime in which the winds change direction in a counterclockwise sense. During the day the sea breezes are suppressed by the backing of the winds as well as the trade and katabatic winds during the night. (Author) [pt

SEA and planning

DEFF Research Database (Denmark)

Stoeglehner, G.; Brown, A.L.; Kørnøv, Lone

2009-01-01

, and the relationship of the SEA to the planning activity itself. This paper focuses on the influence that planners have in these implementation processes, postulating the hypothesis that these are key players in achieving effectiveness in SEA. Based upon implementation theory and empirical experience, the paper......As the field of strategic environmental assessment (SEA) has matured, the focus has moved from the development of legislation, guidelines and methodologies towards improving the effectiveness of SEA. Measuring and of course achieving effectiveness is both complex and challenging. This paper...

Regional transport and dilution during high-pollution episodes in southern France: Summary of findings from the Field Experiment to Constraint Models of Atmospheric Pollution and Emissions Transport (ESCOMPTE)

Science.gov (United States)

Drobinski, P.; SaïD, F.; Ancellet, G.; Arteta, J.; Augustin, P.; Bastin, S.; Brut, A.; Caccia, J. L.; Campistron, B.; Cautenet, S.; Colette, A.; Coll, I.; Corsmeier, U.; Cros, B.; Dabas, A.; Delbarre, H.; Dufour, A.; Durand, P.; GuéNard, V.; Hasel, M.; Kalthoff, N.; Kottmeier, C.; Lasry, F.; Lemonsu, A.; Lohou, F.; Masson, V.; Menut, L.; Moppert, C.; Peuch, V. H.; Puygrenier, V.; Reitebuch, O.; Vautard, R.

2007-07-01

In the French Mediterranean basin the large city of Marseille and its industrialized suburbs (oil plants in the Fos-Berre area) are major pollutant sources that cause frequent and hazardous pollution episodes, especially in summer when intense solar heating enhances the photochemical activity and when the sea breeze circulation redistributes pollutants farther north in the countryside. This paper summarizes the findings of 5 years of research on the sea breeze in southern France and related mesoscale transport and dilution of pollutants within the Field Experiment to Constraint Models of Atmospheric Pollution and Emissions Transport (ESCOMPTE) program held in June and July 2001. This paper provides an overview of the experimental and numerical challenges identified before the ESCOMPTE field experiment and summarizes the key findings made in observation, simulation, and theory. We specifically address the role of large-scale atmospheric circulation to local ozone vertical distribution and the mesoscale processes driving horizontal advection of pollutants and vertical transport and mixing via entrainment at the top of the sea breeze or at the front and venting along the sloped terrain. The crucial importance of the interactions between processes of various spatial and temporal scales is thus highlighted. The advances in numerical modeling and forecasting of sea breeze events and ozone pollution episodes in southern France are also underlined. Finally, we conclude and point out some open research questions needing further investigation.

Regional transport and dilution during high-pollution episodes in southern France: Summary of findings from the Field Experiment to Constraint Models of Atmospheric Pollution and Emissions Transport (ESCOMPTE)

International Nuclear Information System (INIS)

Drobinski, P.; Menut, L.; Ancellet, G.; Bastin, S.; Colette, A.; Said, F.; Brut, A.; Campistron, B.; Cros, B.; Durand, P.; Lohou, F.; Moppert, C.; Puygrenier, V.; Arteta, J.; Cautenet, S.; Augustin, P.; Delbarre, H.; Caccia, J.L.; Guenard, V.; Coll, I.; Lasry, F.; Corsmeier, U.; Hasel, M.; Kalthoff, N.; Kottmeier, C.; Dabas, A.; Dufour, A.; Lemonsu, A.; Masson, V.; Peuch, V.H.; Reitebuch, O.; Vautard, R.

2007-01-01

In the French Mediterranean basin the large city of Marseille and its industrialized suburbs (oil plants in the Fos-Berre area) are major pollutant sources that cause frequent and hazardous pollution episodes, especially in summer when intense solar heating enhances the photochemical activity and when the sea breeze circulation redistributes pollutants farther north in the countryside. This paper summarizes the findings of 5 years of research on the sea breeze in southern France and related mesoscale transport and dilution of pollutants within the Field Experiment to Constraint Models of Atmospheric Pollution and Emissions Transport (ESCOMPTE) program held in June and July 2001. This paper provides an overview of the experimental and numerical challenges identified before the ESCOMPTE field experiment and summarizes the key findings made in observation, simulation, and theory. We specifically address the role of large-scale atmospheric circulation to local ozone vertical distribution and the mesoscale processes driving horizontal advection of pollutants and vertical transport and mixing via entrainment at the top of the sea breeze or at the front and venting along the sloped terrain. The crucial importance of the interactions between processes of various spatial and temporal scales is thus highlighted. The advances in numerical modeling and forecasting of sea breeze events and ozone pollution episodes in southern France are also underlined. Finally, we conclude and point out some open research questions needing further investigation. (authors)

Regional transport and dilution during high-pollution episodes in southern France: Summary of findings from the Field Experiment to Constraint Models of Atmospheric Pollution and Emissions Transport (ESCOMPTE)

Energy Technology Data Exchange (ETDEWEB)

Drobinski, P.; Menut, L. [Ecole Polytechnique, Inst Pierre Simon Laplace, Laboratoire de Meteorologie Dynamique, F-91128 Palaiseau (France); Ancellet, G.; Bastin, S.; Colette, A. [Universite Pierre et Marie Curie, Institut Pierre Simon Laplace, Service d' aeronomie, 4 place Jussieu, F-75252 Paris, (France); Said, F.; Brut, A.; Campistron, B.; Cros, B.; Durand, P.; Lohou, F.; Moppert, C.; Puygrenier, V. [Univ Toulouse, Lab Aerol, F-31400 Toulouse, (France); Arteta, J.; Cautenet, S. [Univ Clermont Ferrand, Lab Meteorol Phys, F-63174 Aubiere, (France); Augustin, P.; Delbarre, H. [Univ Littoral Cote d' Opale, Lab Physicochim Atmosphere, F-59140 Dunkerque, (France); Caccia, J.L.; Guenard, V. [Univ Toulon and Var, Lab Sondages Electromagnet Environm Terr, F-83957 La Garde, (France); Coll, I.; Lasry, F. [Fac Sci and Technol, Lab Interuniv Syst Atmospher, F-94010 Creteil, (France); Corsmeier, U.; Hasel, M.; Kalthoff, N.; Kottmeier, C. [Univ Karlsruhe, Inst Meteorol and Klimaforsch, Forschungszentrum, D-76133 Karlsruhe, (Germany); Dabas, A.; Dufour, A.; Lemonsu, A.; Masson, V.; Peuch, V.H. [Ctr Natl Rech Meteorol, F-31057 Toulouse, (France); Reitebuch, O. [Deutsch Zentrum Luft and Raumfahrt, Inst Atmospher Phys, D-82234 Wessling, (Germany); Vautard, R. [Inst Pierre Simon Laplace, CEA Saclay, Lab Sci Climat and Environm, F-91191 Gif Sur Yvette, (France)

2007-07-01

In the French Mediterranean basin the large city of Marseille and its industrialized suburbs (oil plants in the Fos-Berre area) are major pollutant sources that cause frequent and hazardous pollution episodes, especially in summer when intense solar heating enhances the photochemical activity and when the sea breeze circulation redistributes pollutants farther north in the countryside. This paper summarizes the findings of 5 years of research on the sea breeze in southern France and related mesoscale transport and dilution of pollutants within the Field Experiment to Constraint Models of Atmospheric Pollution and Emissions Transport (ESCOMPTE) program held in June and July 2001. This paper provides an overview of the experimental and numerical challenges identified before the ESCOMPTE field experiment and summarizes the key findings made in observation, simulation, and theory. We specifically address the role of large-scale atmospheric circulation to local ozone vertical distribution and the mesoscale processes driving horizontal advection of pollutants and vertical transport and mixing via entrainment at the top of the sea breeze or at the front and venting along the sloped terrain. The crucial importance of the interactions between processes of various spatial and temporal scales is thus highlighted. The advances in numerical modeling and forecasting of sea breeze events and ozone pollution episodes in southern France are also underlined. Finally, we conclude and point out some open research questions needing further investigation. (authors)

Study of the coastal atmospheric boundary layer during ESCOMPTE 2001. Evaluation and improvement of the efficiency of a UHF radar; Etude de la couche limite atmospherique cotiere durant ESCOMPTE 2001. Evaluation et amelioration des performances d'un radar UHF

Energy Technology Data Exchange (ETDEWEB)

Puygrenier, V

2005-12-15

Forecasting of pollution events was the main objective of the ESCOMPTE-2001 campaign, which took place in the Marseille/Fos/Berre heterogeneous area (southeastern France) in the early summer 2001. This goal requires good understanding and taking into account, by physico-chemical numerical models, of the physical processes in the Atmospheric Boundary Layer (ABL), in which pollutants are emitted, transported and diffused. In the ESCOMPTE-2001 campaign context, this work was devoted to study the low troposphere during sea breeze events, related to meteorological conditions responsible for poor air quality of coastal areas. It presents notably an oscillation of the sea breeze intensity and competitions of locals and regional sea breeze, which change the advective time of the marine air above the continental surface and thus influence the ABL development and its pollutants concentration. This study is based principally on the network of four UHF wind profilers radars set up on the coastal area of Marseille/Fos/Berre, allowing a continuous three-dimensional description of the sea breeze flow and the ABL. For the needs of this phenomenological work, methodological developments was realized to improve the measurement of ABL turbulent properties with UHF radars (terms of turbulent kinetic energy budget) and the use of wind profilers network for the study of pollutants plumes trajectory-graphy. (author)

Study of the coastal atmospheric boundary layer during ESCOMPTE 2001. Evaluation and improvement of the efficiency of a UHF radar; Etude de la couche limite atmospherique cotiere durant ESCOMPTE 2001. Evaluation et amelioration des performances d'un radar UHF

Energy Technology Data Exchange (ETDEWEB)

Puygrenier, V.

2005-12-15

Forecasting of pollution events was the main objective of the ESCOMPTE-2001 campaign, which took place in the Marseille/Fos/Berre heterogeneous area (southeastern France) in the early summer 2001. This goal requires good understanding and taking into account, by physico-chemical numerical models, of the physical processes in the Atmospheric Boundary Layer (ABL), in which pollutants are emitted, transported and diffused. In the ESCOMPTE-2001 campaign context, this work was devoted to study the low troposphere during sea breeze events, related to meteorological conditions responsible for poor air quality of coastal areas. It presents notably an oscillation of the sea breeze intensity and competitions of locals and regional sea breeze, which change the advective time of the marine air above the continental surface and thus influence the ABL development and its pollutants concentration. This study is based principally on the network of four UHF wind profilers radars set up on the coastal area of Marseille/Fos/Berre, allowing a continuous three-dimensional description of the sea breeze flow and the ABL. For the needs of this phenomenological work, methodological developments was realized to improve the measurement of ABL turbulent properties with UHF radars (terms of turbulent kinetic energy budget) and the use of wind profilers network for the study of pollutants plumes trajectory-graphy. (author)

Modeling the feedback between aerosol and boundary layer processes: a case study in Beijing, China.

Science.gov (United States)

Miao, Yucong; Liu, Shuhua; Zheng, Yijia; Wang, Shu

2016-02-01

Rapid development has led to frequent haze in Beijing. With mountains and sea surrounding Beijing, the pollution is found to be influenced by the mountain-plain breeze and sea-land breeze in complex ways. Meanwhile, the presence of aerosols may affect the surface energy balance and impact these boundary layer (BL) processes. The effects of BL processes on aerosol pollution and the feedback between aerosol and BL processes are not yet clearly understood. Thus, the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) is used to investigate the possible effects and feedbacks during a haze episode on 23 September 2011. Influenced by the onshore prevailing wind, sea-breeze, and upslope breeze, about 45% of surface particulate matter (PM)2.5 in Beijing are found to be contributed by its neighbor cities through regional transport. In the afternoon, the development of upslope breeze suppresses the growth of BL in Beijing by imposing a relatively low thermal stable layer above the BL, which exacerbates the pollution. Two kinds of feedback during the daytime are revealed as follows: (1) as the aerosols absorb and scatter the solar radiation, the surface net radiation and sensible heat flux are decreased, while BL temperature is increased, resulting in a more stable and shallower BL, which leads to a higher surface PM2.5 concentration in the morning and (2) in the afternoon, as the presence of aerosols increases the BL temperature over plains, the upslope breeze is weakened, and the boundary layer height (BLH) over Beijing is heightened, resulting in the decrease of the surface PM2.5 concentration there.

Coupling of convection and circulation at various resolutions

Directory of Open Access Journals (Sweden)

Cathy Hohenegger

2015-03-01

Full Text Available A correct representation of the coupling between convection and circulation constitutes a prerequisite for a correct representation of precipitation at all scales. In this study, the coupling between convection and a sea breeze is investigated across three main resolutions: large-eddy resolution where convection is fully explicit, convection-permitting resolution where convection is partly explicit and coarse resolution where convection is parameterised. The considered models are the UCLA-LES, COSMO and ICON. Despite the use of prescribed surface fluxes, comparison of the simulations reveals that typical biases associated with a misrepresentation of convection at convection-permitting and coarser resolutions significantly alter the characteristics of the sea breeze. The coarse-resolution simulations integrated without convective parameterisation and the convection-permitting simulations simulate a too slow propagation of the breeze front as compared to the large-eddy simulations. From the various factors affecting the propagation, a delayed onset and intensification of cold pools primarily explains the differences. This is a direct consequence of a delayed development of convection when the grid spacing is coarsened. Scaling the time the sea breeze reaches the centre of the land patch by the time precipitation exceeds 2 mm day−1, used as a measure for significant evaporation, yields a collapse of the simulations onto a simple linear relationship although subtle differences remain due to the use of different turbulence and microphysical schemes. Turning on the convection scheme significantly disrupts the propagation of the sea breeze due to a misrepresented timing (too early triggering and magnitude (too strong precipitation evaporation in one of the tested convection schemes of the convective processes.

Seasonal Cycle of the Near-Surface Diurnal Wind Field Over the Bay of La Paz, Mexico

Science.gov (United States)

Turrent, Cuauhtémoc; Zaitsev, Oleg

2014-05-01

The results of numerical simulations of the troposphere over the Bay of La Paz, calculated for the months of January, April, July and October during the period 2006-2010 with the Weather Research and Forecast (WRF v3.5) regional model, are used to describe the seasonal features of the diurnal cycle of planetary boundary-layer winds. Two distinct near-surface diurnal flows with strong seasonal variability were identified: (1) a nocturnal and matutinal breeze directed from the subtropical Pacific Ocean, over the Baja California peninsula and the Bay of La Paz, into the Gulf of California that is associated with the regional sea-surface temperature difference between those two major water bodies; and (2) a mid to late afternoon onshore sea-breeze related to the peninsula's daily cycle of insolation heating that evolves with counter-clockwise rotation over the Bay of La Paz. The model results reveal the interaction over Baja California of opposing afternoon sea-breeze fronts that originate from the subtropical Pacific Ocean and the Gulf of California, with a convergence line forming over the peaks of the peninsula's topography and the associated presence of a closed vertical circulation cell over the Bay of La Paz and the adjacent Gulf. The collision of the opposing sea-breeze fronts over the narrow peninsula drives convection that is relatively weak due to the reduced heat source and only appears to produce precipitation sporadically. The spatial structure of the sea-breeze fronts over the Bay of La Paz region is complex due to shoreline curvature and nearby topographic features. A comparison of the numerical results with available meteorological near-surface observations indicates that the modelling methodology adequately reproduced the observed features of the seasonal variability of the local planetary boundary-layer diurnal wind cycle and confirms that the low-level atmospheric circulation over the Bay of La Paz is dominated by kinetic energy in the diurnal band

Local scale atmospheric diffusion at a coastal site in the presence of breeze effect (Phase I and II: data collection at a coastal site and off shore)

International Nuclear Information System (INIS)

Cagnetti, P.; Ferrara, V.; Pellegrini, A.

1985-01-01

The aim of this contract is the characterization, from the thermal and anemological point of view of the lower layers of the atmosphere at a coastal site, affected by breeze circulation. Data are utilized to set up diffusion models for accidental releases of airborne materials, both of short and prolonged duration. Five inland meteorological campaigns, starting from Jan. 82 (Jan., Apr., Jul., Oct. 1982, Jan. 1983), have been carried out; an appropriate extension of the contract allowed the execution of two more campaigns in the open sea (Apr., Jul. 1983), utilizing the oceanographic ship ''Bannock'' kindly supplied by CNR. The analysis of the data showed the development of a well defined IBL during on-shore flow only in Spring and Summer, while an inversion layer was detectable aloft independently of the season (provided that an anticyclonic situation was present). According to those relevant features a simple diffusion model has been developed for short duration releases at local scale. Finally, the analysis and elaboration of the data, collected on site by a meteorological automatic station, allowed the extension of the model to prolonged releases

Coastal-inland solar radiation difference study. Final report

Energy Technology Data Exchange (ETDEWEB)

Bach, W.D. Jr.; Vukovich, F.M.

1980-04-01

The purpose of this study was to quantify the characteristics of solar insolation in the coastal zone and to determine the effect of the sea breeze circulation on the global insolation. In order to satisfy these objectives, a six station sampling network was established in the coastal plain of southeastern North Carolina, where previous evidence has indicated that the sea breeze circulation is almost a daily occurrence from late May through October. Three sites (Sloop Point, Onslow Beach, and Cape Fear Technical Institute (CFTI)) were located near the coast (coastal sites) to assess the insolation at the coast. A site (Clinton) was located in an area seldom affected by the sea breeze (about 100 km from the coast). Two additional sites, Wallace and Ellis Airport, located between the coastal sites and the control site, were to be used to assess the transient impact of the sea breeze upon the insolation. Pyranometers were located at each site to measure the global insolation. Direct normal insolation measured by a pyrheliometer and ultraviolet radiation measured by uv radiometers were observed at the Sloop Point and Clinton sites only. Data were collected during the calendar year 1978. The results of the study indicated that the global insolation had greater variability over the network during the summer season (June, July, and August). During the summer, there was a systematicdiurnal variation of the difference in global insolation between the inland and the coastal sites.

Variability of currents in front of the Venice Lagoon, Northern Adriatic Sea

Directory of Open Access Journals (Sweden)

S. Cosoli

2008-05-01

Full Text Available Time scales and modes of variability of the flow in the water column in the Northern Adriatic Sea for late summer 2002 are described based on current record from a single bottom-mounted ADCP in the shallow-water area in front of the Venice Lagoon.

The time averaged flow was directed 277° E (CCW, roughly aligned with the coastline, with typical magnitudes in the range 4–6 cm/s and a limited, not significant clockwise veering with depth. Tidal forcing was weak and mainly concentrated in the semidiurnal frequency band, with a barotropic (depth-independent structure. On a diurnal time scale, tidal signal was biased by the sea-breeze regime and was characterized by a clockwise veering with depth according to the Ekman spiral.

A complex EOF analysis on the velocity profile time series extracted two dominant spatial modes of variability, which explained more than 90% of the total variance in the current field. More than 78% of the total variance was accounted for by the first EOF mode, with a barotropic structure that contained the low-frequency components and the barotropic tidal signal at semidiurnal and diurnal frequencies. The second mode had a baroclinic structure with a zero-crossing at mid-depth, which was related with the response of the water column to the high-frequency wind-driven diurnal sea breeze variability.

The response of low-passed non-tidal currents to local wind stress was fast and immediate, with negligible temporal lag up to mid-depth. Currents vectors were pointing to the right of wind stress, as expected from the surface Ekman veering, but with angles smaller than the expected ones. A time lag in the range 10 to 11 h was found below 8 m depth, with current vectors pointing to the left of wind stress and a counterclockwise veering towards the bottom. The delay was consistent with the frictional adjustment time scale describing the dynamics of a frictionally dominated flow in shallow water, thus

Variability of currents in front of the Venice Lagoon, Northern Adriatic Sea

Directory of Open Access Journals (Sweden)

S. Cosoli

2008-05-01

Full Text Available Time scales and modes of variability of the flow in the water column in the Northern Adriatic Sea for late summer 2002 are described based on current record from a single bottom-mounted ADCP in the shallow-water area in front of the Venice Lagoon. The time averaged flow was directed 277° E (CCW, roughly aligned with the coastline, with typical magnitudes in the range 4–6 cm/s and a limited, not significant clockwise veering with depth. Tidal forcing was weak and mainly concentrated in the semidiurnal frequency band, with a barotropic (depth-independent structure. On a diurnal time scale, tidal signal was biased by the sea-breeze regime and was characterized by a clockwise veering with depth according to the Ekman spiral. A complex EOF analysis on the velocity profile time series extracted two dominant spatial modes of variability, which explained more than 90% of the total variance in the current field. More than 78% of the total variance was accounted for by the first EOF mode, with a barotropic structure that contained the low-frequency components and the barotropic tidal signal at semidiurnal and diurnal frequencies. The second mode had a baroclinic structure with a zero-crossing at mid-depth, which was related with the response of the water column to the high-frequency wind-driven diurnal sea breeze variability. The response of low-passed non-tidal currents to local wind stress was fast and immediate, with negligible temporal lag up to mid-depth. Currents vectors were pointing to the right of wind stress, as expected from the surface Ekman veering, but with angles smaller than the expected ones. A time lag in the range 10 to 11 h was found below 8 m depth, with current vectors pointing to the left of wind stress and a counterclockwise veering towards the bottom. The delay was consistent with the frictional adjustment time scale describing the dynamics of a frictionally dominated flow in shallow water, thus suggesting the importance of

Coastal atmospheric circulation assessment for emergency off-site dose considerations

International Nuclear Information System (INIS)

Burda, T.J.; Kasprak, A.; Daverio, C.; Martin, G.; Matura, A.D.

1985-01-01

More than 40 nuclear facilities are located near large bodies of water and are influenced by seasonal and diurnal lake/sea breeze phenomena. Atmospheric transport in the vicinity of the Shoreham nuclear power plant is affected, in part, by the sound breeze generated by Long Island Sound and/or the ocean breeze generated by the Atlantic Ocean. The sound and ocean breeze phenomena produce spatial discrepancies in the wind field within the Shoreham Emergency Planning Zone (EPZ) during the morning to early evening hours throughout the spring to early autumn. In addition, there is a potential trajectory reversal to the sound/ocean breeze front. Two simple, easy-to-use procedures were developed that could be used by plant personnel to determine in real time (a) the presence of a sound and/or ocean breeze front located within the Shoreham EPZ and (b) the significant plume impact region resulting from an unscheduled release during this condition

Sea Legs

Science.gov (United States)

Macdonald, Kenneth C.

Forty-foot, storm-swept seas, Spitzbergen polar bears roaming vast expanses of Arctic ice, furtive exchanges of forbidden manuscripts in Cold War Moscow, the New York city fashion scene, diving in mini-subs to the sea floor hot srings, life with the astronauts, romance and heartbreak, and invading the last bastions of male exclusivity: all are present in this fast-moving, non-fiction account of one woman' fascinating adventures in the world of marine geology and oceanography.

Analysis of complex wind regimes at Kennedy Space Center for radiological assessment

International Nuclear Information System (INIS)

Taylor, G.E.; Parks, C.R.; Atchison, M.K.

1989-01-01

Galileo and Ulysses will be launched from the Kennedy Space Center (KSC) during October 1989 and October 1990, respectively. These deep-space probes will contain a radioactive thermoelectric generator as a power source. An accidental breach of the containment vessel housing the generator could cause a leak of radioactive material to the atmosphere. If this occurred, the radioactive cloud would move with the prevailing wind flow pattern and pose a serious health threat to all in its path. Since the KSC/Cape Canaveral (KSC/CC) area of Florida is located in a coastal environment with several different land/water interfaces, complex low-level wind circulation patterns exist throughout the year. Thus, if any transport and diffusion model is to correctly predict the movement of effluent near KSC, it must be able to accurately portray the characteristics of the land/sea breeze flow pattern. To evaluate models used at KSC, the KSC Atmospheric Boundary Layer Experiment (KABLE) has been designed to provide a data set to better define the characteristics of these mesoscale circulations. Data collection for KABLE occurred from November 1, 1988, to October 31, 1989. This paper presents analyses for 1 day during November 1988 that demonstrate the complexity of the local meteorological conditions at KSC/CC. The NUS Corporation has used these data and empirical sea breeze parameters to evaluate their Emergency Dose Assessment System, EMERGE

Influence of flow velocity on motor behavior of sea cucumber Apostichopus japonicus.

Science.gov (United States)

Pan, Yang; Zhang, Libin; Lin, Chenggang; Sun, Jiamin; Kan, Rentao; Yang, Hongsheng

2015-05-15

The influence of flow velocity on the motor behavior of the sea cucumber, Apostichopus japonicus was investigated in the laboratory. Cameras were used to record sea cucumber movements and behavior analysis software was used to measure the distance traveled, time spent, upstream or downstream of the start position and the speed of movements. In general, the mean velocity of A. japonicus was below 0.7mms(-1). The maximum velocity recorded for all the sea cucumbers tested was for a large individual (89.25±17.11g), at a flow rate of 4.6±0.5cms(-1). Medium sized (19.68±5.53g) and large individuals moved significantly faster than small individuals (2.65±1.24g) at the same flow rate. A. japonicus moved significantly faster when there was a moderate current (4.6±0.5cms(-1) and 14.7±0.3cms(-1)), compared with the fast flow rate (29.3±3.7cms(-1)) and when there was no flow (0cms(-1)). Sea cucumbers did not show positive rheotaxis in general, but did move in a downstream direction at faster current speeds. Large, medium and small sized individuals moved downstream at the fastest current speed tested, 29.3±3.7cms(-1). When there was no water flow, sea cucumbers tended to move in an irregular pattern. The movement patterns show that the sea cucumber, A. japonicus can move across the direction of flow, and can move both upstream and downstream along the direction of flow. Copyright © 2015. Published by Elsevier Inc.

The role of mesoscale meteorology in modulating the (222)Rn concentrations in Huelva (Spain)--impact of phosphogypsum piles.

Science.gov (United States)

Hernández-Ceballos, M A; Vargas, A; Arnold, D; Bolívar, J P

2015-07-01

The combined analysis of (222)Rn activity concentrations and mesoscale meteorological conditions at Huelva city (Spain) was addressed in this study to understand the potential impact of phosphogypsum piles on the (222)Rn activity concentrations registered at this area. Hourly mean data from April 2012 to February 2013 registered at two sampling sites (Huelva city and in the background station of El Arenosillo, located 27 km to the south-east) have been used in the study. The results of the present study showed a large difference in mean radon concentrations between the two stations during the sampling period, 6.3 ± 0.4 Bq m(-3) at Huelva and 3.0 ± 0.2 Bq m(-3) at El Arenosillo. The analysis has demonstrated that hourly (222)Rn concentrations at Huelva city above 22 Bq m(-3), with nocturnal peaks up to 50 Bq/m(3), mainly coincided with the occurrence of a pure sea-land breeze cycle. Mesoscale circulations in this region are mainly characterized by two patterns of sea-land breeze, pure and non-pure, with the phosphosypsum piles directly upstream (south) of the city during the afternoon on pure sea-breeze days. The difference between mean (222)Rn activity concentrations at Huelva city were 9.9 ± 1.5 Bq m(-3) for the pure pattern and 3.3 ± 0.5 Bq m(-3) for the non-pure pattern, while in the background station concentrations were 3.9 ± 0.4 Bq m(-3) and 2.8 ± 0.4 Bq m(-3) respectively. Considering these large differences, a detailed analysis of composites and case studies of representative sea-land breeze cycles of both types and their impact on (222)Rn activity concentration was performed. The results suggested that the presence of the phosphogypsum piles was necessary in order to justify the high (222)Rn activity concentrations observed at Huelva compared with the background station in the afternoons on pure sea breeze days (1.5-2.0 Bq m(-3)). On the other hand, large night time differences between the two sites on these days were

Some Observational and Modeling Studies of the Atmospheric Boundary Layer at Mississippi Gulf Coast for Air Pollution Dispersion Assessment

Directory of Open Access Journals (Sweden)

Anjaneyulu Yerramilli

2008-12-01

Full Text Available Coastal atmospheric conditions widely vary from those over inland due to the land-sea interface, temperature contrast and the consequent development of local circulations. In this study a field meteorological experiment was conducted to measure vertical structure of boundary layer during the period 25-29 June, 2007 at three locations Seabee base, Harrison and Wiggins sites in the Mississippi coast. A GPS Sonde along with slow ascent helium balloon and automated weather stations equipped with slow and fast response sensors were used in the experiment. GPS sonde were launched at three specific times (0700 LT, 1300 LT and 1800 LT during the experiment days. The observations indicate shallow boundary layer near the coast which gradually develops inland. The weather research and forecasting (WRF meso-scale atmospheric model and a Lagrangian particle dispersion model (HYSPLIT are used to simulate the lower atmospheric flow and dispersion in a range of 100 km from the coast for 28-30 June, 2007. The simulated meteorological parameters were compared with the experimental observations. The meso-scale model results show significant temporal and spatial variations in the meteorological fields as a result of development of sea breeze flow, its coupling with the large scale flow field and the ensuing alteration in the mixing depth across the coast. Simulated ground-level concentrations of SO2 from four elevated point sources located along the coast indicate diurnal variation and impact of the local sea-land breeze on the direction of the plume. Model concentration levels were highest during the stable morning condition and during the sea-breeze time in the afternoon. The highest concentrations were found up to 40 km inland during sea breeze time. The study illustrates the application of field meteorological observations for the validation of WRF which is coupled to HYSPLIT for dispersion assessment in the coastal region.

On the radar cross section (RCS) prediction of vehicles moving on the ground

Energy Technology Data Exchange (ETDEWEB)

Sabihi, Ahmad [Department of Mathematical Sciences, Sharif University of Technology, Tehran (Iran, Islamic Republic of)

2014-12-10

As readers should be aware, Radar Cross Section depends on the factors such as: Wave frequency and polarization, Target dimension, angle of ray incidence, Target’s material and covering, Type of radar system as monostatic or bistatic, space in which contains target and propagating waves, and etc. Having moved or stationed in vehicles can be effective in RCS values. Here, we investigate effective factors in RCS of moving targets on the ground or sea. Image theory in electromagnetic applies to be taken into account RCS of a target over the ground or sea.

On the radar cross section (RCS) prediction of vehicles moving on the ground

International Nuclear Information System (INIS)

Sabihi, Ahmad

2014-01-01

As readers should be aware, Radar Cross Section depends on the factors such as: Wave frequency and polarization, Target dimension, angle of ray incidence, Target’s material and covering, Type of radar system as monostatic or bistatic, space in which contains target and propagating waves, and etc. Having moved or stationed in vehicles can be effective in RCS values. Here, we investigate effective factors in RCS of moving targets on the ground or sea. Image theory in electromagnetic applies to be taken into account RCS of a target over the ground or sea

Forecast of sea surface temperature off the Peruvian coast using an autoregressive integrated moving average model

Directory of Open Access Journals (Sweden)

Carlos Quispe

2013-04-01

Full Text Available El Niño connects globally climate, ecosystems and socio-economic activities. Since 1980 this event has been tried to be predicted, but until now the statistical and dynamical models are insuffi cient. Thus, the objective of the present work was to explore using an autoregressive moving average model the effect of El Niño over the sea surface temperature (TSM off the Peruvian coast. The work involved 5 stages: identifi cation, estimation, diagnostic checking, forecasting and validation. Simple and partial autocorrelation functions (FAC and FACP were used to identify and reformulate the orders of the model parameters, as well as Akaike information criterium (AIC and Schwarz criterium (SC for the selection of the best models during the diagnostic checking. Among the main results the models ARIMA(12,0,11 were proposed, which simulated monthly conditions in agreement with the observed conditions off the Peruvian coast: cold conditions at the end of 2004, and neutral conditions at the beginning of 2005.

Assessment of radiological impact due to a hypothetical core disruptive accident for PFBR using an advanced atmospheric dispersion system

International Nuclear Information System (INIS)

Srinivas, C.V.; Venkatesan, R.; Natarajan, A.

2004-01-01

Radiological impact due to air borne effluent dispersion from a hypothetical Core Disruptive Accident (CDA) scenario for Prototype Fast Breeder Reactor (PFBR) at Kalpakkam coastal site is estimated using an advanced system consisting of a 3-d meso-scale atmospheric model and a random walk particle dispersion model. A simulation of dispersion for CDA carried out for a typical summer day on 24th May 2003 predicted development of land-sea breeze circulation and Thermal Internal Boundary Layer (TIBL) at Kalpakkam site, which have been confirmed by observations. Analysis of dose distribution corresponding to predicted atmospheric conditions shows maximum dose from stack releases beyond the site boundary at about 4 km during TIBL fumigation and stable conditions respectively. A multi mode spatial concentration distribution has been noticed with diurnal meandering of wind under land sea breeze circulation. Over a meso-scale range of 25 km, turning of plume under sea breeze and maximum concentration along plume centerline at distances of 3 to 10 km have been noticed. The study has enabled to simulate the more complex meteorological situation that is actually present at the site. (author)

A heavy sea fog event over the Yellow Sea in March 2005: Analysis and numerical modeling

Science.gov (United States)

Gao, Shanhong; Lin, Hang; Shen, Biao; Fu, Gang

2007-02-01

In this paper, a heavy sea fog episode that occurred over the Yellow Sea on 9 March 2005 is investigated. The sea fog patch, with a spatial scale of several hundred kilometers at its mature stage, reduced visibility along the Shandong Peninsula coast to 100 m or much less at some sites. Satellite images, surface observations and soundings at islands and coasts, and analyses from the Japan Meteorology Agency (JMA) are used to describe and analyze this event. The analysis indicates that this sea fog can be categorized as advection cooling fog. The main features of this sea fog including fog area and its movement are reasonably reproduced by the Fifth-generation Pennsylvania State University/National Center for Atmospheric Research Mesoscale Model (MM5). Model results suggest that the formation and evolution of this event can be outlined as: (1) southerly warm/moist advection of low-level air resulted in a strong sea-surface-based inversion with a thickness of about 600 m; (2) when the inversion moved from the warmer East Sea to the colder Yellow Sea, a thermal internal boundary layer (TIBL) gradually formed at the base of the inversion while the sea fog grew in response to cooling and moistening by turbulence mixing; (3) the sea fog developed as the TIBL moved northward and (4) strong northerly cold and dry wind destroyed the TIBL and dissipated the sea fog. The principal findings of this study are that sea fog forms in response to relatively persistent southerly warm/moist wind and a cold sea surface, and that turbulence mixing by wind shear is the primary mechanism for the cooling and moistening the marine layer. In addition, the study of sensitivity experiments indicates that deterministic numerical modeling offers a promising approach to the prediction of sea fog over the Yellow Sea but it may be more efficient to consider ensemble numerical modeling because of the extreme sensitivity to model input.

Coastal precipitation formation and discharge based on TRMM observations

OpenAIRE

R. H. Heiblum; I. Koren; O. Altaratz

2011-01-01

The interaction between breezes and synoptic gradient winds creates persistent convergence zones nearby coastlines. The low level convergence of moist air promotes the dynamical and microphysical processes responsible for the formation of clouds and precipitation.

Our work focuses on the winter seasons of 1998–2011 in the Eastern Mediterrenean. During the winter the Mediterrenean sea is usually warmer than the adjacent land, resulting in frequent occurence of land breeze ...

Some atmospheric dispersion, wind and temperature statistics from Jervis Bay, Australian Capital Territory 1972 to 1974

International Nuclear Information System (INIS)

Clark, G.H.

1985-07-01

A meteorological study of winds, temperatures and Pasquill stability categories was conducted in the coastal conditions at Jervis Bay. Three Pasquill stability categorisation schemes were compared. These indicated a predominance of neutral to slightly unstable conditions. During the daytime, north bay breezes and north-east sea breezes were most common together with on-shore south-east winds. Off-shore south-west winds prevailed during winter and were observed most frequently at night

Snow bands over the Gulf of Finland in wintertime

Directory of Open Access Journals (Sweden)

Jordi Mazon

2015-01-01

Full Text Available Large shore-parallel, quasi-stationary snow bands are occasionally observed over the Gulf of Finland during wintertime when the sea is not frozen. On the basis of Weather Research and Forecasting mesoscale model experiments and radar observations of snow bands formed in January 2006 and February 2012, we show that their dynamics share common characteristics: (1 the sea gulf that produces the known lake effect, (2 cold easterly large-scale flow along the gulf and (3 a cold local flow from the two near and opposite coastlines of Estonia and Finland in the form of two land-breeze cells which collide offshore. The associated fronts, which have strong rising motions, are maintained by the convergence of the land-breeze cells. In addition to these factors, the concave shape of the coast in the eastern part of the Gulf of Finland promotes offshore convergence and the formation of several secondary bands of precipitation that are adjacent to the eastern part of the main band. When the easterlies turn to southerlies, horizontal convective rolls appear over the sea. The Estonian land breeze is enhanced while the cold air remains stagnant inland over the Finnish coast, acting as an orographic barrier lifting the marine air mass upwards. Consequently, a line of convective precipitation composed of several cells is formed along the Finnish coast. In both events, the simulations also show two low-level jets generated by the combined effects of the land-breeze cells and baroclinicity over the coast of Finland and Estonia.

A study on atmospheric dispersion around Kalpakkam coastal site using a non-hydrostatic model and comparison with field data

International Nuclear Information System (INIS)

Jamima, P.; Lakshminarasimhan, J.; Venkatesan, R.

2002-01-01

Study of the sea breeze characteristics and Thermal Internal Boundary Layer (TIBL) is very important to understand the dispersion characteristics of air pollutants near coastal area. In the present paper, dispersion characteristics near Kalpakkam coastal area are studied and discussed by simulating sea breeze characteristics and TIBL using a non-hydrostatic mesoscale model in its two dimensional form. The model is run with surface physics, simplified radiation physics and turbulent kinetic energy (TKE) closure scheme for diffusion. A joint meteorological field experiment was carried out by IITM-Pune at Kalpakkam by deploying state of art sensors and tether balloon systems for observing the height profiles of meteorological parameters. The data taken from the field experiment is used here to compare the simulations. Results shows that the onset of sea breeze is one hour before as observed from the field experiment. Slight difference is also seen in wind speed and temperature. Spatial variation of the dispersion pattern could be understood from the simulated TKE profile. From the study, it is shown that the model gives only a over all picture of the real scenario and successful simulations require the inclusion of more atmospheric dynamics such as microphysics, cumulus parameterization and atmospheric radiation. (author)

Analyzing coastal precipitation using TRMM observations

Directory of Open Access Journals (Sweden)

R. H. Heiblum

2011-12-01

Full Text Available The interaction between breezes and synoptic gradient winds, and surface friction increase in transition from sea to land can create persistent convergence zones nearby coastlines. The low level convergence of moist air promotes the dynamical and microphysical processes responsible for the formation of clouds and precipitation.

Our work focuses on the winter seasons of 1998–2011 in the Eastern Mediterranean. During the winter the Mediterranean sea is usually warmer than the adjacent land, resulting in frequent occurrence of land breeze that opposes the common synoptic winds. Using rain-rate vertical profiles from the Tropical Rainfall Measurement Mission (TRMM satellite, we examined the spatial and temporal distribution of average hydrometeor mass in clouds as a function of the distance from coastlines.

Results show that coastlines in the Eastern Mediterranean are indeed favored areas for precipitation formation. The intra-seasonal and diurnal changes in the distribution of hydrometeor mass indicate that the land breeze may likely be the main responsible mechanism behind our results.

Spectral Growth of Hurricane Generated Seas

National Research Council Canada - National Science Library

Finlayson, William

1997-01-01

The characteristics of a growing sea during hurricanes are significantly different from those observed in ordinary storms since the source of energy generating waves is moving and the rate of change...

The influence of terrain forcing on the initiation of deep convection over Mediterranean islands

Science.gov (United States)

Barthlott, Christian; Kirshbaum, Daniel

2013-04-01

The influence of mountainous islands on the initiation of deep convection is investigated using the Consortium for Small-scale Modeling (COSMO) model. The study day is 26 August 2009 on which moist convection occurred over both the Corsica and Sardinia island in the Mediterranean Sea. Sensitivity runs with systematically modified topography are explored to evaluate the relative importance of the land-sea contrast and the terrain height for convection initiation. Whereas no island precipitation is simulated when the islands are completely removed, all simulations that represent these land surfaces develop convective precipitation. Although convection initiates progressively earlier in the day over taller islands, the precipitation rates and accumulations do not show a fixed relationship with terrain height. This is due to the competing effects of different physical processes. First, whereas the forcing for low-level ascent increases over taller islands, the boundary-layer moisture supply decreases, which diminishes the conditional instability and precipitable water. Second, whereas taller islands enhance the inland propagation speeds of sea-breeze fronts, they also mechanically block these fronts and prevent them from reaching the island interior. As a result, the island precipitation is rather insensitive to island terrain height except for one particular case in which the island precipitation increases considerably due to an optimal superposition of the sea breeze and upslope flow. These results demonstrate the complexity of interactions between sea breezes and orography and reinforce that an adequate representation of detailed topographic features is necessary to account for thermally induced wind systems that initiate deep convection.

Effect of Land-Use Change on the Urban Heat Island in the Fukuoka–Kitakyushu Metropolitan Area, Japan

Directory of Open Access Journals (Sweden)

Yoichi Kawamoto

2017-08-01

Full Text Available In coastal cities, the effect of the sea breeze in mitigating the urban heat island (UHI phenomenon has attracted attention. This study targeted the Fukuoka–Kitakyushu metropolitan area, the fourth largest metropolitan area in Japan which is also coastal. Doppler Light Detection And Ranging (LiDAR observations were conducted in the summer of 2015 to clarify the transition of the wind field over the targeted area. To investigate the effects on the UHI of land-use change related to urbanization, the National Land Numerical Information (NLNI land-use datasets for Japan in 1976 (NLNI-76 and 2009 (NLNI-09 were used in the Weather Research and Forecasting (WRF model. The results of the simulation showed that most of the northern part of the Kyushu region became warmer, with an average increase of +0.236 °C for the whole simulation period. Comparing the two simulations and the Doppler LiDAR observations, the simulation results with the NLNI-09 dataset (for the year closest to the study period in 2015 showed closer conformity with the observations. The results of the simulation using NLNI-76 showed faster sea breeze penetration and higher wind velocity than the observations. These results suggest that the land-use change related to urbanization weakened the sea breeze penetration in this area.

On the sea surface temperature high in the Lakshadweep Sea before the onset of the southwest monsoon

Digital Repository Service at National Institute of Oceanography (India)

Shenoi, S.S.C.; Shankar, D.; Shetye, S.R.

The north Indian Ocean becomes the warmest area of the world oceans prior to the onset of southwest monsoon in June. During this period a zonal band of high sea surface temperature (SST), the ``thermal equator'' (TE), moves over this region...

Atmospheric electrical field measurements near a fresh water reservoir and the formation of the lake breeze

Directory of Open Access Journals (Sweden)

Francisco Lopes

2016-06-01

Full Text Available In order to access the effect of the lakes in the atmospheric electrical field, measurements have been carried out near a large man-made lake in southern Portugal, the Alqueva reservoir, during the ALqueva hydro-meteorological EXperiment 2014. The purpose of these conjoint experiments was to study the impact of the Alqueva reservoir on the atmosphere, in particular on the local atmospheric electric environment by comparing measurements taken in the proximity of the lake. Two stations 10 km apart were used, as they were located up- and down-wind of the lake (Amieira and Parque Solar, respectively, in reference to the dominant northwestern wind direction. The up-wind station shows lower atmospheric electric potential gradient (PG values than the ones observed in the down-wind station between 12 and 20 UTC. The difference in the atmospheric electric PG between the up-wind and the down-wind station is ~30 V/m during the day. This differential occurs mainly during the development of a lake breeze, between 10 and 18 UTC, as a consequence of the surface temperature gradient between the surrounding land and the lake water. In the analysis presented, a correlation is found between the atmospheric electric PG differences and both wind speed and temperature gradients over the lake, thus supporting the influence of the lake breeze over the observed PG variation in the two stations. Two hypotheses are provided to explain this observation: (1 The air that flows from the lake into the land station is likely to increase the local electric conductivity through the removal of ground dust and the transport of cleaner air from higher altitudes with significant light ion concentrations. With such an increase in conductivity, it is expected to see a reduction of the atmospheric electric PG; (2 the resulting air flow over the land station carries negative ions formed by wave splashing in the lake's water surface, as a result of the so-called balloelectric effect

Diurnal Variation of Rainfall Associated with Tropical Depression in South China and its Relationship to Land-Sea Contrast and Topography

Directory of Open Access Journals (Sweden)

Yuchun Zhao

2013-12-01

Full Text Available Convective precipitation associated with tropical depression (TD is one primary type of post-flooding season rainfall in South China (SC. Observations of the Tropical Rainfall Measuring Mission (TRMM satellite have shown specific diurnal features of convective rainfall in South China, which is somewhat different from that in other seasons or regions of China. Convective precipitation is usually organized into a rainfall band along the southeastern coast of South China in the early morning hours. The rainfall band develops and intensifies quickly in the morning, then moves inland in the afternoon and, finally, diminishes at night. The daily convective rainfall along the coast is much more than that in the inland region, and heavy rainfall is often found along the coast. A long-duration heavy rainfall event associated with tropical depression “Fitow” during the period from 28 August to 6 September 2001, is selected in this study to explore the diurnal feature of convective rainfall and its formation mechanism. Modeling results of the 10-day heavy rainfall event are compared with both rain-gauge observation and satellite-retrieved rainfall. Total precipitation and its spatial distribution, as well as diurnal variations are reasonably simulated and agree well with observations. Further analysis reveals that the development and movement of convective precipitation is mainly related to the land and sea breezes. The anomalous height-latitudinal circulation in the morning-to-noon hours is completely reversed in the afternoon-to-late-evening hours, with the convective rainfall swinging back and forth, following its updraft branch. Sensitivity experiments show that the afternoon convective rainfall in the inland region of SC is caused by the diurnal variation of solar radiation forcing. The mountain range along the coast and the complex topography in the inland region of SC plays a critical role in the enhancement of diurnal convective rainfall

Development and propagation of a pollution gradient in the marine ...

Indian Academy of Sciences (India)

are significantly influenced by the diurnal cycle of coastal sea-land breeze circulations along India's west coast. Transport of ... cloud bands during INDOEX were in fact pollu- tion gradients ...... State Climate Office of North Carolina. We thank.

Portrait of a Warming Ocean and Rising Sea Levels: Trend of Sea Level Change 1993-2008

Science.gov (United States)

2008-01-01

Warming water and melting land ice have raised global mean sea level 4.5 centimeters (1.7 inches) from 1993 to 2008. But the rise is by no means uniform. This image, created with sea surface height data from the Topex/Poseidon and Jason-1 satellites, shows exactly where sea level has changed during this time and how quickly these changes have occurred. It's also a road map showing where the ocean currently stores the growing amount of heat it is absorbing from Earth's atmosphere and the heat it receives directly from the Sun. The warmer the water, the higher the sea surface rises. The location of heat in the ocean and its movement around the globe play a pivotal role in Earth's climate. Light blue indicates areas in which sea level has remained relatively constant since 1993. White, red, and yellow are regions where sea levels have risen the most rapidly up to 10 millimeters per year and which contain the most heat. Green areas have also risen, but more moderately. Purple and dark blue show where sea levels have dropped, due to cooler water. The dramatic variation in sea surface heights and heat content across the ocean are due to winds, currents and long-term changes in patterns of circulation. From 1993 to 2008, the largest area of rapidly rising sea levels and the greatest concentration of heat has been in the Pacific, which now shows the characteristics of the Pacific Decadal Oscillation (PDO), a feature that can last 10 to 20 years or even longer. In this 'cool' phase, the PDO appears as a horseshoe-shaped pattern of warm water in the Western Pacific reaching from the far north to the Southern Ocean enclosing a large wedge of cool water with low sea surface heights in the eastern Pacific. This ocean/climate phenomenon may be caused by wind-driven Rossby waves. Thousands of kilometers long, these waves move from east to west on either side of the equator changing the distribution of water mass and heat. This image of sea level trend also reveals a significant

Journal of Earth System Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Volume 115, Issue 2. April 2006, pages 185-265. pp 185-201. Transitions in the surface energy balance during the life cycle of a monsoon season · T N Krishnamurti Mrinal .... pp 229-234. Impact of sea breeze on wind-seas off Goa, west coast of India · S Neetu Satish Shetye P Chandramohan · More Details Abstract Fulltext ...

NASA Applied Sciences' DEVELOP National Program: Summer 2010 Florida Agriculture

Science.gov (United States)

Cooley, Zachary C.; Billiot, Amanda; Lee, Lucas; McKee, Jake

2010-01-01

The main agricultural areas in South Florida are located within the fertile land surrounding Lake Okeechobee. The Atlantic Watershed monthly rainfall anomalies showed a weak but statistically significant correlation to the Oceanic Nino Index (ONI). No other watershed s anomalies showed significant correlations with ONI or the Southern Oscillation Index (SOI). During La Nina months, less sea breeze days and more disturbed days were found to occur compared to El Nino and neutral months. The increase in disturbed days can likely by attributed to the synoptic pattern during La Nina, which is known to be favorable for tropical systems to follow paths that affect South Florida. Overall, neither sea breeze rainfall patterns nor total rainfall patterns in South Florida s main agricultural areas were found to be strongly influenced by the El Nino Southern Oscillation during our study time.

Impact of Lake Okeechobee Sea Surface Temperatures on Numerical Predictions of Summertime Convective Systems over South Florida

Science.gov (United States)

Case, Jonathan L.; Splitt, Michael E.; Fuell, Kevin K.; Santos, Pablo; Lazarus, Steven M.; Jedlovec, Gary J.

2009-01-01

The NASA Short-term Prediction Research and Transition (SPoRT) Center, the Florida Institute of Technology, and the NOAA/NWS Weather Forecast Office at Miami, FL (MFL) are collaborating on a project to investigate the impact of using high-resolution, 2-km Moderate Resolution Imaging Spectroradiometer (MODIS) sea surface temperature (SST) composites within the Weather Research and Forecasting (WRF) prediction system. The NWS MFL is currently running WRF in real-time to support daily forecast operations, using the National Centers for Environmental Prediction Nonhydrostatic Mesoscale Model dynamical core within the NWS Science and Training Resource Center's Environmental Modeling System (EMS) software. Twenty-seven hour forecasts are run daily initialized at 0300, 0900, 1500, and 2100 UTC on a domain with 4-km grid spacing covering the southern half of Florida and adjacent waters of the Gulf of Mexico and Atlantic Ocean. The SSTs are initialized with the NCEP Real-Time Global (RTG) analyses at 1/12deg resolution. The project objective is to determine whether more accurate specification of the lower-boundary forcing over water using the MODIS SST composites within the 4-km WRF runs will result in improved sea fluxes and hence, more accurate e\\olutiono f coastal mesoscale circulations and the associated sensible weather elements. SPoRT conducted parallel WRF EMS runs from February to August 2007 identical to the operational runs at NWS MFL except for the use of MODIS SST composites in place of the RTG product as the initial and boundary conditions over water. During the course of this evaluation, an intriguing case was examined from 6 May 2007, in which lake breezes and convection around Lake Okeechobee evolved quite differently when using the high-resolution SPoRT MODIS SST composites versus the lower-resolution RTG SSTs. This paper will analyze the differences in the 6 May simulations, as well as examine other cases from the summer 2007 in which the WRF

In situ airborne measurements of aerosol optical properties during photochemical pollution events

Science.gov (United States)

Mallet, M.; van Dingenen, R.; Roger, J. C.; Despiau, S.; Cachier, H.

2005-02-01

Dry aerosol optical properties (scattering, absorbing coefficients, and single scattering albedo) were derived from in situ airborne measurements during two photochemical pollution events (25 and 26 June) observed during the Experience sur Site pour Contraindre les Modeles de Pollution atmospherique et de Transport d'Emissions (ESCOMPTE) experiment. Two flights were carried out during daytime (one during the morning and one at noon) over a domain, allowing the investigation of how an air pollution event affects the particle optical properties. Both horizontal distribution and vertical profiles are presented. Results from the horizontal mapping show that plumes of enhanced scattering and absorption are formed in the planetary boundary layer (PBL) during the day in the sea breeze-driven outflow of the coastal urban-industrial area of Marseille-Fos de Berre. The domain-averaged scattering coefficient (at 550 nm) over land σs changes from 35 (28) Mm-1 during land breeze to 63 (43) Mm-1 during sea breeze on 25 June (26 June), with local maxima reaching > 100 Mm-1. The increase in the scattering coefficient is associated with new particle formation, indicative of secondary aerosol formation. Simultaneously, the domain-averaged absorption coefficient increases from 5.6 (3.4) Mm-1 to 9.3 (8.0) Mm-1. The pollution plume leads to strong gradients in the single scattering albedo ωo over the domain studied, with local values as low as 0.73 observed inside the pollution plume. The role of photochemistry and secondary aerosol formation during the 25 June case is shown to increase ωo and to make the aerosol more `reflecting' while the plume moves away from the sources. The lower photochemical activity, observed in the 26 June case, induces a relatively higher contribution of black carbon, making the aerosol more absorbing. Results from vertical profiles at a single near-urban location in the domain indicate that the changes in optical properties happen almost entirely within

Allied Forces, Mediterranean Theater, Western Task Force Operation Plan Number 4-44, Volume 1

Science.gov (United States)

1944-07-24

breezes. Of the teo the sea breeze is usually the stronger, at times attaining a velocity of 14-10 knots for one to two hours in the early part of...30, 575t 895, 1205, and 1*125 kcs . Ships desiring calibration should make arrangements With the station communication officer one day prior to...in KSGO, para­ graph SAID LETTERS GA GB GO Hi KB HC JA JB JC KA KB KC LA LB LC MA MB MC NA NB NC OA OB 00 PA PB PC 0> Q3 QC RA HB RC SA

Observations of vegetation induced breezes and their impact on convection

Science.gov (United States)

Garcia-Carreras, Luis; Parker, Douglas J.; Taylor, Christopher M.; Reeves, Claire; Murphy, Jennifer

2010-05-01

Aircraft observations over Benin during the early afternoon of 17 August 2006 are used to look at the impact of heterogeneities in vegetation cover, primarily between crop and forest/shrub, on the thermodynamic and dynamical properties of the planetary boundary layer (PBL). Isoprene, a biogenic organic compound emitted primarily by woody vegetation species, was measured and is used to link the vegetation patterns to the PBL properties. The aircraft observations show the presence of a persistent mesoscale organization of the winds persisting over two hours, controlling the pattern of cumulus congestus cloud in the area. The mesoscale flows are closely linked to temperature anomalies that mirror the vegetation patterns at the surface. These results are consistent with the presence of higher Bowen ratios over forested areas, associated with higher evapotranspiration and isoprene emissions, producing negative PBL temperature anomalies over the forested area compared to adjacent cropland. The temperature gradients that thus arise at vegetation boundaries are then sufficient to initiate vegetation breezes. The relationships between PBL temperatures and isoprene, linking the land-surface to the PBL, and PBL temperatures and winds are very significant for length-scales above 10 and 8km respectively. The convergence zones, and therefore clouds, associated with the land-induced mesoscale flows tend to occur on the southern edge of the warm temperature anomalies. This is attributed to the presence of a northerly synoptic flow, which strengthens the southerly parts of the mesoscale flow, as well as displacing the convergence zones southward. A visible satellite climatology for the whole season shows an enhancement of cloud over the cropland during the early afternoon, consistent with the presence of land-induced flows. These results suggest that the presence of these flows have a climatological impact on the initiation of convection in the region.

Exchanges in boundary layer and low troposphere and consequences on pollution of Fos-Berre-Marseille area (ESCOMPTE experiment)

International Nuclear Information System (INIS)

Moppert, C.

2006-02-01

The aim of this study is to analyse the vertical structure of the low troposphere during the ESCOMPTE campaign in relation with transport and diffusion of pollutants. This analysis shows the difficulty to define a boundary layer. It allows us to highlight a complex superposition of several internal boundary layers, particularly near the coast. The study of the layer where pollution may be accumulated or diluted pointed out the fact that pollution is trapped near the surface, close to the coastline under sea-breeze conditions whereas it is advected over the mountains where the boundary layers are deeper. During sea-breeze conditions, the ozone concentration is paradoxically weak near the sources at the coastline (titration). Over the mountains, the strong developments of the boundary layers result in a mixing between the highly polluted low troposphere and the surface which enhances the ozone concentration. (author)

Exchanges in boundary layer and low troposphere and consequences on pollution of Fos-Berre-Marseille area (ESCOMPTE experiment); Echanges dans la couche limite et la base troposphere et consequences sur la pollution dans la region de Fos-Berre-Marseille (Experience ESCOMPTE)

Energy Technology Data Exchange (ETDEWEB)

Moppert, C

2006-02-15

The aim of this study is to analyse the vertical structure of the low troposphere during the ESCOMPTE campaign in relation with transport and diffusion of pollutants. This analysis shows the difficulty to define a boundary layer. It allows us to highlight a complex superposition of several internal boundary layers, particularly near the coast. The study of the layer where pollution may be accumulated or diluted pointed out the fact that pollution is trapped near the surface, close to the coastline under sea-breeze conditions whereas it is advected over the mountains where the boundary layers are deeper. During sea-breeze conditions, the ozone concentration is paradoxically weak near the sources at the coastline (titration). Over the mountains, the strong developments of the boundary layers result in a mixing between the highly polluted low troposphere and the surface which enhances the ozone concentration. (author)

The behaviour of ozone and peroxyacetyl nitrate concentrations for different wind regimes during the MEDCAPHOT-TRACE campaign in the greater area of Athens, Greece

DEFF Research Database (Denmark)

Suppan, P.; Fabian, P.; Vyras, L.

1998-01-01

As a part of an international experimental field campaign, the association of air pollution with sea breeze circulation in the Greater Athens Area (GAA) is discussed on the basis of the behaviour of ozone and peroxyacetyl nitrate (PAN). During typical sea breeze days inside the Athens basin the o...... a straight line across the Athens basin ranging From the island of Aegina in the Gulf of Saronikos to the northern border of the GAA show distinct peaks due to the pollution cloud NEPHOS. (C) 1998 Published by Elsevier Science Ltd. All rights reserved....... the ozone levels reach values up to 66% greater than values outside the basin. There is also an increase in ozone and PAN mixing ratios from the south to the north and from lower to higher locations, within the GAA. On-line PAN-measurements with a time resolution of 5 min at three sites located almost along...

Cloud Formation, Sea-Air-Land Interaction, Mozambique, Africa

Science.gov (United States)

1991-01-01

This rare depiction of the physical interactions of air land and sea in cloud formation was seen over Mozambique (12.0S, 40.5E). Moist low air, heated as it moves over land, rises and forms clouds. Even the coastal islands have enough heat to initiate the process. Once begun, the circulation is dynamic and the descending motion suppresses cloud formation on either side of the cloud stream. As clouds move inland, they rise to follow the land upslope.

Characteristics of local winds in northwest Hawaii

International Nuclear Information System (INIS)

Schroeder, T.A.

1981-01-01

During the period 22--29 June 1978, meteorological data were collected at six stations arranged in nearly linear transection extending from the coast at Anaehoomalu, Hawaii to Waimea Airport, 25 km inland and 800 m higher. Sea breeze response to synoptic-scale weather patterns was documented

Persistency of atmospheric diffusion conditions in Angra dos Reis - Brazil

International Nuclear Information System (INIS)

Nicolli, D.

1981-12-01

Based on a 2 year observation period, the diffusion conditions at the Almirante Alvaro Alberto N.P.P. site, in Angra dos Reis, are analized with respect to persistency as a function of the wind direction, the Pasquill stability class and the time of the day. The Pasquill stability class relates to the bulk vertical temperature gradient measured between 2m and 50m in the atmosphere; the wind direction is measured at 50m height. The persistency is defined in this report as the probability that the wind direction will remain longer than a given time in a sector without change in the diffusion category by more than a certain stage. During the day the persistency is mostly affected by the sea breeze with predominance of the unstable and neutral categories. At night the stable categories dominate. The alternating sea and land breezes disturb daily the trade wind field resulting in low persistency of the diffusion conditions. (Author) [pt

The inland boundary layer at low latitudes

Science.gov (United States)

Garratt, J. R.

1985-08-01

Observations from the Koorin boundary-layer experiment in Australia (latitude 16 °S) were analysed in a study of the nocturnal jet development. For geostrophic winds in the range 10 20 m s-1, ageostrophic wind magnitudes of 5 10m s-1 were common above the surface layer near sunset, with cross-isobar flow angles of about 40 °. The jet that then developed by midnight was probably the result of these large ageostrophic winds, strong surface cooling and favourable baroclinity and sloping terrain. The analysis is supported by numerical model calculations with special emphasis on the role of long-wave radiative cooling on turbulent decay. Decay is rapid in the presence of radiation, although there is little influence on stress divergence levels. Evidence of sea-breeze influences on the jet evolution, and on features of deeply penetrating sea breezes in general, will be presented and discussed in part 2 of this study (submitted to Boundary-Layer Meteorol.).

Comparison between HF radar current data and moored ADCP currentmeter

International Nuclear Information System (INIS)

Cosoli, S.

2005-01-01

A preliminary assessment of accuracy of a two-sites shore-based HF Radar network along the Venice Lagoon littoral was attempted by means of comparison with a 57.5 day-long ADCP current time series for the period September-October 2002. Results showed that radar measurements were accurate ( O . The main differences between the HF radar and surface ADCP currents can be explained in terms of random errors affecting the measurement technique and the daily sea breeze forcing, since low-pass filtering of current time series significantly improved the correlation and decreased the RMS of the differences between the two measured data set. Comparison of the semidiurnal (M2, S2) tidal band suggested good agreement between tidal ellipse amplitudes. Wind forcing on a daily time-scale (sea-breeze) was associated with larger differences between radar and ADCP currents at a diurnal band due to the presence of a vertical shear in the surface layer

The use of fractionated fly ash of thermal power plants as binder for production of briquettes of coke breeze and dust

Science.gov (United States)

Temnikova, E. Yu; Bogomolov, A. R.; Lapin, A. A.

2017-11-01

In this paper, we propose to use the slag and ash material of thermal power plants (TPP) operating on pulverized coal fuel. The elemental and chemical composition of fly ash of five Kuzbass thermal power plants differs insignificantly from the composition of the mineral part of coking coal because coke production uses a charge, whose composition defines the main task: obtaining coke with the required parameters for production of iron and steel. These indicators are as follows: CRI reactivity and strength of the coke residue after reaction with CO2 - CSR. The chemical composition of fly ash of thermal power plants and microsilica with bulk density of 0.3-0.6 t/m3 generated at production of ferroalloys was compared. Fly ash and microsilica are the valuable raw material for production of mineral binder in manufacturing coke breeze briquettes (fraction of 2-10 mm) and dust (0-200 μm), generated in large quantities during coking (up to 40wt%). It is shown that this binder is necessary for production of smokeless briquettes with low reactivity, high strength and cost, demanded for production of cupola iron and melting the silicate materials, basaltic rocks in low-shaft furnaces. It is determined that microsilica contains up to 90% of silicon oxide, and fly ash contains up to 60% of silicon oxide and aluminum oxide of up to 20%. On average, the rest of fly ash composition consists of basic oxides. According to calculation by the VUKHIN formula, the basicity index of briquette changes significantly, when fly ash is introduced into briquette raw material component as a binder. The technology of coke briquette production on the basis of the non-magnetic fraction of TPP fly ash in the ratio from 3.5:1 to 4.5:1 (coke breeze : coke dust) with the addition of the binder component to 10% is proposed. The produced briquettes meet the requirements by CRI and require further study on CSR requirements.

A case study in atmospheric lead pollution of Northern-German coastal regions

Energy Technology Data Exchange (ETDEWEB)

Kapitza, H.; Eppel, D.P. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Gewaesserphysik

1998-12-31

Transport and deposition of atmospheric lead over the coastal zone of Northern Germany are investigated. It is shown that marked differences in the impact of the ecologically valuable wadden sea areas can occur between summer and winter time. Due to the formation of sea breeze systems in summer the coastal zone is likely to be less stressed than in winter when the pollutant is confined to a shallow layer above ground. (orig.) 10 refs.

Analyzing coastal precipitation using TRMM observations

OpenAIRE

R. H. Heiblum; I. Koren; O. Altaratz

2011-01-01

The interaction between breezes and synoptic gradient winds, and surface friction increase in transition from sea to land can create persistent convergence zones nearby coastlines. The low level convergence of moist air promotes the dynamical and microphysical processes responsible for the formation of clouds and precipitation.

Our work focuses on the winter seasons of 1998–2011 in the Eastern Mediterranean. During the winter the Mediterranean sea is usually warmer than t...

Wind and thermodynamic profiler observations of a late-mature gust ...

Indian Academy of Sciences (India)

ground level during the gust front passage. These updrafts were present from above the nose level to top of the head. ... Land/sea breezes, thunderstorm outflows, and some shallow cold ..... orological events that accompanied GFs: a rise in pressure, a ...... ation, organization, and lifetime associated with Florida boundary ...

Observational evidence for remote forcing of the west India coastal current

Digital Repository Service at National Institute of Oceanography (India)

Shetye, S.R.; Suresh, I.; Shankar, D.; Sundar, D.; Jayakumar, S.; Mehra, P.; Desai, R.G.P.; Pednekar, P.S.

OF THE WICC and Shetye, 1997] was forced both remotely and locally at periods exceeding 10 days; at periods less than 10 days, the WICC was locally forced. The next section describes the data used; Section 3 de- scribes the relationship between sea level... in the vicinity of the anemome- ter. The along-shore component of the wind is shown in Fig- ure 3; also plotted is the along-shore wind decimated with a 0.75 day −1 (∼ 32 hours) filter to remove the sea-breeze cycle. During the ICMAM observations, sea level...

Impacts of Detailed Land-Use Types and Urban Heat in an Urban Canopy Model on Local Meteorology and Ozone Levels for Air Quality Modeling in a Coastal City, Korea

Directory of Open Access Journals (Sweden)

Yoon-Hee Kang

2016-01-01

Full Text Available An urban canopy model (UCM, with detailed urban land-use and anthropogenic heat information, is required to reproduce and understand the urbanization process and its impact on regional climate and urban air quality. This study investigates the UCM impact on simulated meteorology and surface ozone in the coastal city of Busan using the WRF-SMOKE-CMAQ model coupled with (UCM case, and without the UCM (NOUCM case. The UCM and NOUCM case results suggest that UCM case generally produces warmer temperatures and deeper planetary boundary layer (PBL heights, especially in the early morning and night time, than the NOUCM case. Owing to urban heating and enhanced turbulent mixing incorporation in the center of the city, the sea breeze in the UCM case tends to penetrate faster and more strongly than in the NOUCM case. After sea breeze arrival at the urban center, the urban heat island effect prevents its penetration further inland. In the UCM case in the late afternoon, local meteorological changes induce remarkable increases in simulated O3 concentrations over the downwind (up to 17.1 ppb and downtown (up to 10.6 ppb areas. This is probably due to an increase in temperature in the urban areas and the wind convergence zone movement due to the sea breeze interaction and offshore flows. The increase in O3 concentration in the late afternoon results in the model bias reduction under previously underestimated O3 conditions due to high NOx emissions. The simulated O3 concentrations in the UCM case are more similar to the observed O3 concentrations compared to those of the NOUCM case.

Physico-Chemical behaviour analysis of air pollutants in a complex coastal site: Castellon; Analisis fisico-quimico de los valores de concentracion de contaminantes en un emplazamiento costero complejo: Castellon

Energy Technology Data Exchange (ETDEWEB)

Andres, M D; Martin, M; Plaza, J; Millan, M

1989-07-01

In January, July and August 1988 two experimental campaigns were launched in the surroundings of the Castellon industrial area located at the Spanish East coast and considered as a complex coastal site. The objective was to complement the mosaic on meso-scale flows on the pollutants concentration fields. A careful study of pollutants concentration cycles related to meteorological parameters, enables the characterization of concentration patterns at the chosen location. Surface atmospheric dynamic in this area in controlled by local cycles of NW nocturnal drainage and E-SSE diumal sea-breeze lows. These cycles are also affected by the formation of thermal low over the center of thee peninsula on summer days. Large scale synoptic conditions appear more frequently during the winter. A transportable laboratory was used to register ten minutes averaged values of O{sub 3} , NO, HO{sub 2} and SO{sub 2}. This unit was placed in the zone of influence of the coastal industries during the sea-breeze regime. The temporal evolution of the pollutant concentrations was analyzed and shows the existence of repeated patters of ground level concentrations under similar meteorological conditions. High ozone values have been detected to be associated with the sea-breeze onset. On the basis of short-term backward trajectories, it has been possible to identity the source of the SO{sub 2} and NO{sub 2} peaks. The obtained concentration values can have a broad origin: rural, marine, traffic, oil fired power plant and refinery emissions, and urban plume. Summer and winder data obtained under similar meteorological conditions have been compared. The temporal evolution of the pollutant concentrations is very similar. (Author) 15 refs.

Physico-Chemical behaviour analysis of air pollutants in a complex coastal site: Castellon

International Nuclear Information System (INIS)

Andres, M. D.; Martin, M.; Plaza, J.; Millan, M.

1989-01-01

In January, July and August 1988 two experimental campaigns were launched in the surroundings of the Castellon industrial area located at the Spanish East coast and considered as a complex coastal site. The objective was to complement the mosaic on meso-scale flows on the pollutants concentration fields. A careful study of pollutants concentration cycles related to meteorological parameters, enables the characterization of concentration patterns at the chosen location. Surface atmospheric dynamic in this area in controlled by local cycles of NW nocturnal drainage and E-SSE diumal sea-breeze lows. These cycles are also affected by the formation of thermal low over the center of thee peninsula on summer days. Large scale synoptic conditions appear more frequently during the winter. A transportable laboratory was used to register ten minutes averaged values of O 3 , NO, HO 2 and SO 2 . This unit was placed in the zone of influence of the coastal industries during the sea-breeze regime. The temporal evolution of the pollutant concentrations was analyzed and shows the existence of repeated patters of ground level concentrations under similar meteorological conditions. High ozone values have been detected to be associated with the sea-breeze onset. On the basis of short-term backward trajectories, it has been possible to identity the source of the SO 2 and NO 2 peaks. The obtained concentration values can have a broad origin: rural, marine, traffic, oil fired power plant and refinery emissions, and urban plume. Summer and winder data obtained under similar meteorological conditions have been compared. The temporal evolution of the pollutant concentrations is very similar. (Author) 15 refs

Physico-chemical behaviour analysis of air pollutants in a complex coastal site: Castellon

International Nuclear Information System (INIS)

Andres, M.D.; Martin, M.; Plaza, J.; Millan, M.

1989-01-01

In Jaunary, July and August 1988 two experimental campaigns were launched in the surroundings of the Castellon industrial area located at the Spanish East coast and considered as a complex coastal site. The objetive was to complement the mosaic on meso-scale flows on the pollutants concentration fields. A careful study of pollutants concentration cycles related to meteorological parameters, enables the characterization of concentration patterns at the chose location. Surface atmospheric dynamic in this area in controlled by local cycles of NW nocturnal drainage and E-SSE diumal sea-breeze flows. These cycles arae also affected by the formation of thermal low over the center of the peninsula on summer days. Large scale synoptic conditions appear more frequently during the winter. A transportable laboratory was used to register ten minutes averaged values of O 3 , NO, NO 2 and SO 2 . This unit was placed in the zone of influence of the coastal industries during the sea-breeze regime. The temporal evolution of the pollutant concentrations was analyzed and shows the existence of repeated patterns of ground level concentrations under similar meteorological conditions. High ozone values have been detected to be associated with the sea-breeze onset. On the basis of short-term backward trajectories, it has been possible ot identify the source of the SO 2 and NO 2 peaks. The obtained concentration values can have a broad origin: rural, marine, traffic, oil fired power plant and refinery emissions, and urban plume. Summer and winter data obtained under similar meteorological conditions have been compared. The temporal evolution of the pollutant concentrations is very similar. (Author)

PM2.5 and Associated Ionic Species in a Sub-urban Coastal Area of Kuala Terengganu, Southern South China Sea (Malaysia)

International Nuclear Information System (INIS)

Norhayati Mohd Tahir; Meikee, Koh; Suhaimi Suratman

2013-01-01

PM 2.5 mass concentration and associated water-soluble ionic species in a sub-urban coastal area of Kuala Terengganu, Malaysia were investigated intermittently from year 2006 to 2009. A total of 78 weekly PM 2.5 samples were analyzed. The mass concentration of PM 2.5 exhibited annual, seasonal and diurnal variations. Temporal distributions of rainfall, sporadic haze episodes and local air flow (sea breeze circulation) were factors controlling PM 2.5 mass variations in the study area. Although the PM 2.5 concentrations were increased during haze episodes in 2006 (August and October) and 2007 (October), their concentrations however, were still within the international guidelines. The average concentration of individual ions was in decreasing trend; SO 4 2- > NH 4 + > K + > Na + > NO 3 - > Cl - > Ca 2+ . The concentrations of SO 42- and NH 4 + accounted for > 70 % of the water-soluble aerosol mass. More than 80 % of ionic species associated with PM 2.5 are from non-marine sources. Major processes affecting the ionic composition of PM 2.5 are biomass burning, crustal loading and sea spray. Air quality mitigation strategies should focus on anthropogenic activities emitting SO 2 , which promotes aerosol SO 4 2- formation. (author)

Arctic sea ice a major determinant in Mandt's black guillemot movement and distribution during non-breeding season

Science.gov (United States)

Divoky, G.J.; Douglas, David C.; Stenhouse, I. J.

2016-01-01

Mandt's black guillemot (Cepphus grylle mandtii) is one of the few seabirds associated in all seasons with Arctic sea ice, a habitat that is changing rapidly. Recent decreases in summer ice have reduced breeding success and colony size of this species in Arctic Alaska. Little is known about the species' movements and distribution during the nine month non-breeding period (September–May), when changes in sea ice extent and composition are also occurring and predicted to continue. To examine bird movements and the seasonal role of sea ice to non-breeding Mandt's black guillemots, we deployed and recovered (n = 45) geolocators on individuals at a breeding colony in Arctic Alaska during 2011–2015. Black guillemots moved north to the marginal ice zone (MIZ) in the Beaufort and Chukchi seas immediately after breeding, moved south to the Bering Sea during freeze-up in December, and wintered in the Bering Sea January–April. Most birds occupied the MIZ in regions averaging 30–60% sea ice concentration, with little seasonal variation. Birds regularly roosted on ice in all seasons averaging 5 h d−1, primarily at night. By using the MIZ, with its roosting opportunities and associated prey, black guillemots can remain in the Arctic during winter when littoral waters are completely covered by ice.

Sea breeze-induced wind sea growth in the central west coast of India.

Digital Repository Service at National Institute of Oceanography (India)

Aboobacker, V.M.; Seemanth, M.; Samiksha, S.V.; Sudheesh, K.; Kerkar, J.; Vethamony, P.

breaking and bottom friction, and refraction and shoaling due to depth variations. The formulation is based on the wave action conservation equation [Komen et al., 1994; Young, 1999], where the directional-frequency wave action spectrum is the dependent... using a fractional step approach where a multi-sequence explicit method is applied for the propagation of wave action [DHI, 2009]. 5    MIKE 21 SW model includes two different formulations: a directional decoupled parametric formulation and a fully...

Bangkok and its air pollution problem

Energy Technology Data Exchange (ETDEWEB)

Panich, S.

1995-12-31

Bangkok is the city on a former river delta and is a very flat area. The topography is unremarkable but being only a few kilometers (about 20) from the sea in the Gulf of Bangkok, the City experiences the sea breeze every afternoon and evening. The natural phenomenon is caused by the uplifting of hot air from the sun-baked ground and heat generation in the city, to be replaced by the cooler air from the sea, which is to the south. During the nighttime the sea breeze ceases to operate as the ground temperature cools down. The late night and early morning is characterized by the calm or no wind. With 2.1 million vehicles, the city has a serious problem of carbon monoxide from the gasoline vehicles stuck in the traffic on start and stop cycles, while particulate matter is the result of diesel vehicles. Hydrocarbons mainly result from two-stroke motorcycles and tuk-tuk (three-wheeled) taxis. Air pollution in Bangkok and major cities of Thailand is the result of emissions from gasoline, diesel, and LPG fueled vehicles, which contribute to the observed levels of carbon monoxide, lead, particulate matter, sulfur dioxide, nitrogen dioxide, ozone and hydrocarbons. The industrial activities contribute smaller share due to tall stacks and more efficient combusting processes and pollution control.

Theory versus practice in Strategic Environmental Assessment (SEA)

Energy Technology Data Exchange (ETDEWEB)

Lobos, Víctor, E-mail: vlobosg@gmail.com [CEG-IST, Instituto Superior Técnico, Universidade de Lisboa, Research Group on Strategic Approaches to Environment and Sustainability (SENSU), 1049-001 Lisboa (Portugal); Centro de Estudios del Desarrollo, San Crescente 551, Las Condes, Santiago (Chile); Partidario, Maria [CEG-IST, Instituto Superior Técnico, Universidade de Lisboa, Research Group on Strategic Approaches to Environment and Sustainability (SENSU), 1049-001 Lisboa (Portugal)

2014-09-15

Could the theory of Strategic Environmental Assessment (SEA) be ahead of its time and decoupled from its practice? This paper evolved in search for this leading research question. Over the years the discourse on SEA experienced a gradual shift from the technocratic and rationalist thinking that supported its origin to more strategic approaches and integrated concepts, suggested since the mid 1990's. In this paper we share the results of our analysis of international thinking and practical experience with SEA. Results reveal that SEA practice changes very slowly when compared to advanced thinking supporting the noted shift. Current SEA practice shows to be still predominantly rooted in the logic of projects' environmental impact assessment (EIA). It is strongly bound to legal and regulatory requirements, and the motivation for its application persists being the delivery of environmental (or final) reports to meet legal obligations. Even though advanced SEA theoretical thinking claim its potential to help decisions to look forward, change mind-sets and the rationale of decision-making to meet sustainability challenges and enhance societal values, we note a weak relationship between the theoretical development of SEA and its practice. Why is this happening? Which factors explain this apparent inertia, resistance to change, in the SEA practice? Results appear to demonstrate the influence of assumptions, understandings, concepts, and beliefs in the use of SEA, which in turn suggest the political sensitivity of the instrument. - Highlights: • Theoretical thinking in SEA is ahead of its time. • SEA international practice reveals inertia to move out of project’ EIA comfort zone. • World current SEA practice show similar understandings of 30 years ago. • 100 world reports and survey of practitioners supported world review. • SEA great challenge is to change paradigms into new scientific complexity theories.

Theory versus practice in Strategic Environmental Assessment (SEA)

International Nuclear Information System (INIS)

Lobos, Víctor; Partidario, Maria

2014-01-01

Could the theory of Strategic Environmental Assessment (SEA) be ahead of its time and decoupled from its practice? This paper evolved in search for this leading research question. Over the years the discourse on SEA experienced a gradual shift from the technocratic and rationalist thinking that supported its origin to more strategic approaches and integrated concepts, suggested since the mid 1990's. In this paper we share the results of our analysis of international thinking and practical experience with SEA. Results reveal that SEA practice changes very slowly when compared to advanced thinking supporting the noted shift. Current SEA practice shows to be still predominantly rooted in the logic of projects' environmental impact assessment (EIA). It is strongly bound to legal and regulatory requirements, and the motivation for its application persists being the delivery of environmental (or final) reports to meet legal obligations. Even though advanced SEA theoretical thinking claim its potential to help decisions to look forward, change mind-sets and the rationale of decision-making to meet sustainability challenges and enhance societal values, we note a weak relationship between the theoretical development of SEA and its practice. Why is this happening? Which factors explain this apparent inertia, resistance to change, in the SEA practice? Results appear to demonstrate the influence of assumptions, understandings, concepts, and beliefs in the use of SEA, which in turn suggest the political sensitivity of the instrument. - Highlights: • Theoretical thinking in SEA is ahead of its time. • SEA international practice reveals inertia to move out of project’ EIA comfort zone. • World current SEA practice show similar understandings of 30 years ago. • 100 world reports and survey of practitioners supported world review. • SEA great challenge is to change paradigms into new scientific complexity theories

Gas nad mud volcanism formation as a result of geodynamic development of the Black sea region

International Nuclear Information System (INIS)

Dmitrievsky, A.N.; Karakin, A.V.; Kazmin, V.G.

2002-01-01

Full text : Fluidodynamic model of moving of gas-mud mixture accompanied by eruptions of mud volcanoes and gas bursts is firstly demonstrated by the example of the Black sea basin. The entire spectrum of gas bursts can be divided into gas and mud-fluid volcanoes. Emanation of hydrocarbon gases during the eruptions accompanied by powerful exploison, bursts of gas, water and fragments of rocks as well as by issue of breccia are typical for the first type of volcanoes. It was suggested that the eastern part of the Black sea forms block or subplate moving to the northeast. This conclusion is important for estimation of seismic and connected geological hazard in the studied region. It was established that deformations and seismicity were mainly confined to the edges of the East Black sea subplate while in its inner part the level of seismic activity is considerably lower.

Two years observations on the diurnal evolution of coastal atmospheric boundary layer features over Thiruvananthapuram (8.5∘ N, 76.9∘ E), India

Science.gov (United States)

Anurose, T. J.; Subrahamanyam, D. Bala; Sunilkumar, S. V.

2018-01-01

The atmospheric boundary layer (ABL) over a given coastal station is influenced by the presence of mesoscale sea breeze circulation, together with the local and synoptic weather, which directly or indirectly modulate the vertical thickness of ABL ( z ABL). Despite its importance in the characterization of lower tropospheric processes and atmospheric modeling studies, a reliable climatology on the temporal evolution of z ABL is not available over the tropics. Here, we investigate the challenges involved in determination of the ABL heights, and discuss an objective method to define the vertical structure of coastal ABL. The study presents a two year morphology on the diurnal evolution of the vertical thickness of sea breeze flow ( z SBF) and z ABL in association with the altitudes of lifting condensation level ( z LCL) over Thiruvananthapuram (8.5∘ N, 76.9∘ E), a representative coastal station on the western coastline of the Indian sub-continent. We make use of about 516 balloon-borne GPS sonde measurements in the present study, which were carried out as part of the tropical tropopause dynamics field experiment under the climate and weather of the sun-earth system (CAWSES)-India program. Results obtained from the present study reveal major differences in the temporal evolution of the ABL features in relation to the strength of sea breeze circulation and monsoonal wind flow during the winter and summer monsoon respectively. The diurnal evolution in z ABL is very prominent in the winter monsoon as against the summer monsoon, which is attributed to the impact of large-scale monsoonal flow over the surface layer meteorology. For a majority of the database, the z LCL altitudes are found to be higher than that of the z ABL, indicating a possible decoupling of the ABL with the low-level clouds.

Investigation of the atmospheric boundary layer dynamics during the ESCOMPTE campaign

Science.gov (United States)

Saïd, F.; Brut, A.; Campistron, B.; Cousin, F.

2007-03-01

This paper presents some results about the behavior of the atmospheric boundary layer observed during the ESCOMPTE experiment. This campaign, which took place in south-eastern France during summer 2001, was aimed at improving our understanding of pollution episodes in relation to the dynamics of the lower troposphere. Using a large data set, as well as a simulation from the mesoscale non-hydrostatic model Meso-NH, we describe and analyze the atmospheric boundary layer (ABL) development during two specific meteorological conditions of the second Intensive Observation Period (IOP). The first situation (IOP2a, from 22 June to 23 June) corresponds to moderate, dry and cold northerly winds (end of Mistral event), coupled with a sea-breeze in the lower layer, whereas sea-breeze events with weak southerly winds occurred during the second part of the period (IOP2b, from 24 June to 26 June). In this study, we first focus on the validation of the model outputs with a thorough comparison of the Meso-NH simulations with fields measurements on three days of the IOP: 22 June, 23 June and 25 June. We also investigate the structure of the boundary layer on IOP2a when the Mistral is superimposed on a sea breeze. Then, we describe the spatial and diurnal variability of the ABL depths over the ESCOMPTE domain during the whole IOP. This step is essential if one wants to know the depth of the layer where the pollutants can be diluted or accumulated. Eventually, this study intends to describe the ABL variability in relation to local or mesoscale dynamics and/or induced topographic effects, in order to explain pollution transport processes in the low troposphere.

Investigation of the atmospheric boundary layer dynamics during the ESCOMPTE campaign

Directory of Open Access Journals (Sweden)

F. Saïd

2007-03-01

Full Text Available This paper presents some results about the behavior of the atmospheric boundary layer observed during the ESCOMPTE experiment. This campaign, which took place in south-eastern France during summer 2001, was aimed at improving our understanding of pollution episodes in relation to the dynamics of the lower troposphere. Using a large data set, as well as a simulation from the mesoscale non-hydrostatic model Meso-NH, we describe and analyze the atmospheric boundary layer (ABL development during two specific meteorological conditions of the second Intensive Observation Period (IOP. The first situation (IOP2a, from 22 June to 23 June corresponds to moderate, dry and cold northerly winds (end of Mistral event, coupled with a sea-breeze in the lower layer, whereas sea-breeze events with weak southerly winds occurred during the second part of the period (IOP2b, from 24 June to 26 June.

In this study, we first focus on the validation of the model outputs with a thorough comparison of the Meso-NH simulations with fields measurements on three days of the IOP: 22 June, 23 June and 25 June. We also investigate the structure of the boundary layer on IOP2a when the Mistral is superimposed on a sea breeze. Then, we describe the spatial and diurnal variability of the ABL depths over the ESCOMPTE domain during the whole IOP. This step is essential if one wants to know the depth of the layer where the pollutants can be diluted or accumulated. Eventually, this study intends to describe the ABL variability in relation to local or mesoscale dynamics and/or induced topographic effects, in order to explain pollution transport processes in the low troposphere.

Investigation of the atmospheric boundary layer dynamics during the ESCOMPTE campaign

Energy Technology Data Exchange (ETDEWEB)

Said, F.; Campistron, B. [Centre de Recherches Atmospheriques, UMR CNRS 5560, Campistrous (France); Brut, A. [Centre d' Etudes Spatiales de la BIOsphere UMR 5126, Toulouse (France); Cousin, F. [Lab. d' Aerologie, UMR CNRS 5560, Toulouse (France)

2007-07-01

This paper presents some results about the behavior of the atmospheric boundary layer observed during the ESCOMPTE experiment. This campaign, which took place in south-eastern France during summer 2001, was aimed at improving our understanding of pollution episodes in relation to the dynamics of the lower troposphere. Using a large data set, as well as a simulation from the mesoscale non-hydrostatic model Meso-NH, we describe and analyze the atmosphere boundary layer (ABL) development during two specific meteorological conditions of the second Intensive Observation Period (IOP). The first situation (IOP2a, from 22 June to 23 June) corresponds to moderate, dry and cold northerly winds (end of Mistral event), coupled with a sea-breeze in the lower layer, whereas sea-breeze events with weak southerly winds occurred during the second part of the period (IOP2b, from 24 June to 26 June). In this study, we first focus on the validation of the model outputs with a thorough comparison of the Meso-NH simulations with fields measurements on three days of the IOP: 22 June, 23 June and 25 June. We also investigate the structure of the boundary layer on IOP2a when the Mistral is superimposed on a sea breeze. Then, we describe the spatial and diurnal variability of the ABL depths over the ESCOMPTE domain during the whole IOP. This step is essential if one wants to know the depth of the layer where the pollutants can be diluted or accumulated. Eventually, this study intends to describe the ABL variability in relation to local or mesoscale dynamics and/or induced topographic effects, in order to explain pollution transport processes in the low troposphere. (orig.)

Investigation of the atmospheric boundary layer dynamics during the ESCOMPTE campaign

Directory of Open Access Journals (Sweden)

F. Saïd

2007-03-01

Full Text Available This paper presents some results about the behavior of the atmospheric boundary layer observed during the ESCOMPTE experiment. This campaign, which took place in south-eastern France during summer 2001, was aimed at improving our understanding of pollution episodes in relation to the dynamics of the lower troposphere. Using a large data set, as well as a simulation from the mesoscale non-hydrostatic model Meso-NH, we describe and analyze the atmospheric boundary layer (ABL development during two specific meteorological conditions of the second Intensive Observation Period (IOP. The first situation (IOP2a, from 22 June to 23 June corresponds to moderate, dry and cold northerly winds (end of Mistral event, coupled with a sea-breeze in the lower layer, whereas sea-breeze events with weak southerly winds occurred during the second part of the period (IOP2b, from 24 June to 26 June. In this study, we first focus on the validation of the model outputs with a thorough comparison of the Meso-NH simulations with fields measurements on three days of the IOP: 22 June, 23 June and 25 June. We also investigate the structure of the boundary layer on IOP2a when the Mistral is superimposed on a sea breeze. Then, we describe the spatial and diurnal variability of the ABL depths over the ESCOMPTE domain during the whole IOP. This step is essential if one wants to know the depth of the layer where the pollutants can be diluted or accumulated. Eventually, this study intends to describe the ABL variability in relation to local or mesoscale dynamics and/or induced topographic effects, in order to explain pollution transport processes in the low troposphere.

The influence of the Amundsen Sea Low on the winds in the Ross Sea and surroundings: Insights from a synoptic climatology

Science.gov (United States)

Coggins, Jack H. J.; McDonald, Adrian J.

2015-03-01

The Amundsen Sea Low (ASL) is an area of climatologically low atmospheric pressure situated over the Southern Ocean. The depth and location of this feature have significant effects on winds, temperature, moisture transport, and sea ice in its vicinity. In this article, we quantify the modulating effect of this feature on winds over the Ross Sea and Ross Ice Shelf. We examine composites of surface winds sampled according to extrema in ASL depth, longitude, and latitude. We employ the output of a previously developed synoptic climatology to identify the explanatory synoptic-scale forcings. In autumn, winter, and spring (AWS) we find that the impact of the depth of the ASL is smaller than that of its location. The ASL moves eastward when it is deep, thereby reducing its influence on Ross Sea winds. When the ASL is northward, we find strongly enhanced southerly flows over the Ross Sea and Ice Shelf, forced by greater cyclonic activity in the north of the Ross Sea. In summer, we find increased cyclonic flow coinciding with a deeper ASL, despite the ASL being located in the Bellingshausen Sea at this time. The responses to the ASL longitude and latitude are profoundly different to those in AWS, suggesting that relationships are strongly dependent on the varying seasonal location of the low. We examine two metrics of the ASL depth and identify that the absolute mean sea level pressure (MSLP) has a more widespread response than that of the relative MSLP.

The mechanism of coking pressure generation I: Effect of high volatile matter coking coal, semi-anthracite and coke breeze on coking pressure and plastic coal layer permeability

Energy Technology Data Exchange (ETDEWEB)

Seiji Nomura; Merrick Mahoney; Koichi Fukuda; Kenji Kato; Anthony Le Bas; Sid McGuire [Nippon Steel Corporation, Chiba (Japan). Environment and Process Technology Center

2010-07-15

One of the most important aspects of the cokemaking process is to control and restrain the coking pressure since excessive coking pressure tends to lead to operational problems and oven wall damage. Therefore, in order to understand the mechanism of coking pressure generation, the permeability of the plastic coal layer and the coking pressure for the same single coal and the same blended coal were measured and the relationship between them was investigated. Then the 'inert' (pressure modifier) effect of organic additives such as high volatile matter coking coal, semi-anthracite and coke breeze was studied. The coking pressure peak for box charging with more uniform bulk density distribution was higher than that for top charging. It was found that the coking pressure peaks measured at different institutions (NSC and BHPBilliton) by box charging are nearly the same. The addition of high volatile matter coking coal, semi-anthracite and coke breeze to a low volatile matter, high coking pressure coal greatly increased the plastic layer permeability in laboratory experiments and correspondingly decreased the coking pressure. It was found that, high volatile matter coking coal decreases the coking pressure more than semi-anthracite at the same plastic coal layer permeability, which indicates that the coking pressure depends not only on plastic coal layer permeability but also on other factors. Coking pressure is also affected by the contraction behavior of the coke layer near the oven walls and a large contraction decreases the coal bulk density in the oven center and hence the internal gas pressure in the plastic layer. The effect of contraction on coking pressure needs to be investigated further. 33 refs., 18 figs., 5 tabs.

Currents in the Eastern Irish Sea

International Nuclear Information System (INIS)

Howarth, M.J.

1983-01-01

Low level radioactive waste is discharged from the nuclear re-processing plant at Sellafield, Cumbria. Its movement away from the discharge point is determined by the Irish Sea's dynamics, both for the soluble compounds and for those compounds which become attached to the sediment. Near Sellafield the tidal currents are weak and parallel to the shore, becoming stronger east/west to the north and south of the Isle of Man. Wind driven currents near Sellafield are predominantly north-westward, strongest near the coast, and oppose the other low frequency currents. Hence, the soluble effluent will initially be dispersed parallel to the shore by the weak tidal currents, moving episodically, southeastward during weak winds and northwestward during storms. Eventually it will leave the Irish Sea, flowing northward through the North Channel. (author)

Influence of sea ice cover and icebergs on circulation and water mass formation in a numerical circulation model of the Ross Sea, Antarctica

Science.gov (United States)

Dinniman, Michael S.; Klinck, John M.; Smith, Walker O.

2007-11-01

Satellite imagery shows that there was substantial variability in the sea ice extent in the Ross Sea during 2001-2003. Much of this variability is thought to be due to several large icebergs that moved through the area during that period. The effects of these changes in sea ice on circulation and water mass distributions are investigated with a numerical general circulation model. It would be difficult to simulate the highly variable sea ice from 2001 to 2003 with a dynamic sea ice model since much of the variability was due to the floating icebergs. Here, sea ice concentration is specified from satellite observations. To examine the effects of changes in sea ice due to iceberg C-19, simulations were performed using either climatological ice concentrations or the observed ice for that period. The heat balance around the Ross Sea Polynya (RSP) shows that the dominant term in the surface heat budget is the net exchange with the atmosphere, but advection of oceanic warm water is also important. The area average annual basal melt rate beneath the Ross Ice Shelf is reduced by 12% in the observed sea ice simulation. The observed sea ice simulation also creates more High-Salinity Shelf Water. Another simulation was performed with observed sea ice and a fixed iceberg representing B-15A. There is reduced advection of warm surface water during summer from the RSP into McMurdo Sound due to B-15A, but a much stronger reduction is due to the late opening of the RSP in early 2003 because of C-19.

Statistical Modeling of Sea Ice Concentration Using Satellite Imagery and Climate Reanalysis Data in the Barents and Kara Seas, 1979–2012

Directory of Open Access Journals (Sweden)

Jihye Ahn

2014-06-01

Full Text Available Extensive sea ice over Arctic regions is largely involved in heat, moisture, and momentum exchanges between the atmosphere and ocean. Some previous studies have been conducted to develop statistical models for the status of Arctic sea ice and showed considerable possibilities to explain the impacts of climate changes on the sea ice extent. However, the statistical models require improvements to achieve better predictions by incorporating techniques that can deal with temporal variation of the relationships between sea ice concentration and climate factors. In this paper, we describe the statistical approaches by ordinary least squares (OLS regression and a time-series method for modeling sea ice concentration using satellite imagery and climate reanalysis data for the Barents and Kara Seas during 1979–2012. The OLS regression model could summarize the overall climatological characteristics in the relationships between sea ice concentration and climate variables. We also introduced autoregressive integrated moving average (ARIMA models because the sea ice concentration is such a long-range dataset that the relationships may not be explained by a single equation of the OLS regression. Temporally varying relationships between sea ice concentration and the climate factors such as skin temperature, sea surface temperature, total column liquid water, total column water vapor, instantaneous moisture flux, and low cloud cover were modeled by the ARIMA method, which considerably improved the prediction accuracies. Our method may also be worth consideration when forecasting future sea ice concentration by using the climate data provided by general circulation models (GCM.

The Dead Sea

Science.gov (United States)

2006-01-01

The Dead Sea is the lowest point on Earth at 418 meters below sea level, and also one of the saltiest bodies of water on Earth with a salinity of about 300 parts-per-thousand (nine times greater than ocean salinity). It is located on the border between Jordan and Israel, and is fed by the Jordan River. The Dead Sea is located in the Dead Sea Rift, formed as a result of the Arabian tectonic plate moving northward away from the African Plate. The mineral content of the Dead Sea is significantly different from that of ocean water, consisting of approximately 53% magnesium chloride, 37% potassium chloride and 8% sodium chloride. In the early part of the 20th century, the Dead Sea began to attract interest from chemists who deduced that the Sea was a natural deposit of potash and bromine. From the Dead Sea brine, Israel and Jordan produce 3.8 million tons potash, 200,000 tons elemental bromine, 45,000 tons caustic soda, 25, 000 tons magnesium metal, and sodium chloride. Both countries use extensive salt evaporation pans that have essentially diked the entire southern end of the Dead Sea. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining

THE METHOD OF TRANSHIPMENT OF GOODS BETWEEN SHIPS IN OPEN SEA (STS

Directory of Open Access Journals (Sweden)

Ali BAIAZIT

2013-05-01

Full Text Available The transhipment method is using a cable trolley system. The two ships are moving on parallel way inthe same direction, between them is suspended carrying the trolley wire. Transhipment of goods is made usingcontainer boxes which are caught by the trolley load jacks. The method offers the advantage of highproductivity, regardless of sea conditions. Basically, the system is usable at high degree of agitation of the sea.Slack in the cable carrier is assured by an automatic tension-adjusting device.

Journal of Earth System Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

The strong NW and SW winds (3.2–3.7ms−1) and wind-driven waves and currents seem to have acted effectively at the mouth of the estuary in developing turbidity maximum. The impact of sea breeze appears nearly same as that of trade winds and cannot be underestimated in sediment resuspension and deposition.

Moving In, Moving Through, and Moving Out: The Transitional Experiences of Foster Youth College Students

Science.gov (United States)

Gamez, Sara I.

2017-01-01

The purpose of this qualitative study was to explore the transitional experiences of foster youth college students. The study explored how foster youth experienced moving into, moving through, and moving out of the college environment and what resources and strategies they used to thrive during their college transitions. In addition, this study…

Acoustic Doppler Current Profiler observations in the southern Caspian Sea: shelf currents and flow field off Feridoonkenar Bay, Iran

Directory of Open Access Journals (Sweden)

P. Ghaffari

2010-07-01

Full Text Available The results of offshore bottom-mounted ADCP measurements and wind records carried out from August to September 2003 in the coastal waters off Feridoon-kenar Bay (FB in the south Caspian Sea (CS are examined in order to characterize the shelf motion, the steady current field and to determine the main driving forces of currents on the study area. Owing to closed basin and absence of the astronomical tide, the atmospheric forcing plays an important role in the flow field of the CS. The lasting regular sea breeze system is present almost throughout the year. This system performs the forcing in diurnal and semi-diurnal bands similar to tides in other regions. In general, current field in the continental shelf could be separated into two distinguishable schemes, which in cross-shelf direction is dominated by high frequencies (1 cpd and higher frequencies, and in along-shelf orientation mostly proportional to lower frequencies in synoptic weather bands. Long-period wave currents, whose velocities are much greater than those of direct wind-induced currents, dominates the current field in the continental shelf off FB. The propagation of the latter could be described in terms of shore-controlled waves that are remotely generated and travel across the shelf in the southern CS. It has also been shown that long term displacements in this area follow the classic cyclonic, circulation pattern in the southern CS.

Simulation of the convective mixed layer in Athens

Energy Technology Data Exchange (ETDEWEB)

Frank, H.P. [Risoe National Lab., Roskilde (Denmark)

1997-10-01

The region of Athens, Greece, has a highly complicated terrain with irregular coastline and mountains next to the sea. This results in complex flow fields. A case study of a simulation of a sea breeze with the Karlsruhe Atmospheric Mesoscale model KAMM is presented together with remarks on the advection of mixed layer air. The valley of Athens is open to the sea towards the south-west and surrounded by mountains on the other sides. Gaps between the mountains channel the flow into the valley. Simulations were done for 14 September 1994 to compare them with measurements at 6 masts by Risoe during the MEDCAPHOT-TRACE experiment. (au)

Sea level trends in South East Asian Seas (SEAS)

Science.gov (United States)

Strassburg, M. W.; Hamlington, B. D.; Leben, R. R.; Manurung, P.; Lumban Gaol, J.; Nababan, B.; Vignudelli, S.; Kim, K.-Y.

2014-10-01

Southeast Asian Seas (SEAS) span the largest archipelago in the global ocean and provide a complex oceanic pathway connecting the Pacific and Indian Oceans. The SEAS regional sea level trends are some of the highest observed in the modern satellite altimeter record that now spans almost two decades. Initial comparisons of global sea level reconstructions find that 17 year sea level trends over the past 60 years exhibit good agreement in areas and at times of strong signal to noise associated decadal variability forced by low frequency variations in Pacific trade winds. The SEAS region exhibits sea level trends that vary dramatically over the studied time period. This historical variation suggests that the strong regional sea level trends observed during the modern satellite altimeter record will abate as trade winds fluctuate on decadal and longer time scales. Furthermore, after removing the contribution of the Pacific Decadal Oscillation (PDO) to sea level trends in the past twenty years, the rate of sea level rise is greatly reduced in the SEAS region. As a result of the influence of the PDO, the SEAS regional sea level trends during 2010s and 2020s are likely to be less than the global mean sea level (GMSL) trend if the observed oscillations in wind forcing and sea level persist. Nevertheless, long-term sea level trends in the SEAS will continue to be affected by GMSL rise occurring now and in the future.

Engaging a moving target: Adapting to rates of climate change

Science.gov (United States)

Shayegh, S.; Caldeira, K.; Moreno-Cruz, J.

2015-12-01

Climate change is affecting the planet and its human and natural systems at an increasing rate. As temperatures continue to rise, the international community has increasingly been considering adaptation measures to prepare for future climate change. However, most discussion around adaptation strategies has focused on preparedness for some expected amount of climate change impacts, e.g. 2 meters sea level rise. In this study, we discuss adaptation to rates of change as an alternative conceptual framework for thinking about adaptation. Adaptation is not only about adapting to amounts of change, but the rate at which these changes occur is also critically important. We ground our discussion with an example of optimal coastal investment in the face of ongoing sea level rise. Sea level rise threatens coastal assets. Finite resources could be devoted to building infrastructure further inland or to building coastal defense systems. A possible policy response could be to create a "no-build" coastal buffer zone that anticipates a future higher sea level. We present a quantitative model that illustrates the interplay among various important factors (rate of sea level rise, discount rate, capital depreciation rate, attractiveness of coastal land, etc). For some cases, strategies that combine periodic defensive investments (e.g. dikes) with planned retreat can maximize welfare when adapting to rates of climate change. In other cases, planned retreat may be optimal. It is important to prepare for ongoing increasing amounts of climate change. Preparing for a fixed amount of climate change can lead to a suboptimal solution. Climate is likely to continue changing throughout this century and beyond. To reduce adverse climate impacts, ecosystems and human systems will need to continuously adapt to a moving target.

Method of decommissioning nuclear reactor building by utilizing sea water buyoancy

International Nuclear Information System (INIS)

Iwashima, Sumio; Ogoshi, Shigeru; Kobari, Shin-ichi.

1989-01-01

Upon dismantling nuclear reactor buildings, peripheral yards are excavated and channels leading to sea shore are formed. Since the outer walls of the reactor buildings are made of iron-reinforced concretes, the opening poritons are grouted with concretes to attain a tightly such closed structure that radioactive wastes, etc. in the inside are not flown out upon reactor discommisioning. Peripheral buildings at relatively low level of radiation contaminations are dismantled and withdrawn. The fundations of the nuclear reactor buildings were dug out and jacked to separate base rocks and the reactor buildings. Then, sea water is introduced into the water channels to entirely float up the buildings. A water gate is disposed in the water channel on the side of sea shore to control the level of sea water. The buildings are moved and guided to the sea shore and towed to a site optimum as a permanent storage area and then burried in that place. The operation period for the discommissioning work can greatly be shortened and the radiation dose and the amount of the wastes can be reduced. (T.M.)

Physical approach to air pollution climatological modelling in a complex site

Energy Technology Data Exchange (ETDEWEB)

Bonino, G [Torino, Universita; CNR, Istituto di Cosmo-Geofisica, Turin, Italy); Longhetto, A [Ente Nazionale per l' Energia Elettrica, Centro di Ricerca Termica e Nucleare, Milan; CNR, Istituto di Cosmo-Geofisica, Turin, Italy); Runca, E [International Institute for Applied Systems Analysis, Laxenburg, Austria

1980-09-01

A Gaussian climatological model which takes into account physical factors affecting air pollutant dispersion, such as nocturnal radiative inversion and mixing height evolution, associated with land breeze and sea breeze regimes, has been applied to the topographically complex area of La Spezia. The measurements of the dynamic and thermodynamic structure of the lower atmosphere obtained by field experiments are utilized in the model to calculate the SO/sub 2/ seasonal average concentrations. The model has been tested on eight three-monthly periods by comparing the simulated values with the ones measured at the SO/sub 2/ stations of the local air pollution monitoring network. Comparison of simulated and measured values was satisfactory and proved the applicability of the model for urban planning and establishment of air quality strategies.

Meteorological research studies at Jervis Bay, Australia

International Nuclear Information System (INIS)

Clark, G.H.; Bendun, E.O.K.

1974-07-01

A climatological study of the winds and temperature from the Jervis Bay region which commenced in October 1970 has shown the presence of a coastal sea breeze and secondary bay breeze circulation system. In an attempt to define the influence of the Murray's Beach site on the local atmospheric dispersion, special smoke plume photography studies were conducted in the lower atmosphere. In June 1972 a meteorological acoustic sounding research programme was initiated at the Jervis Bay settlement. The aims of the research are to calibrate the sounder in terms of surface wind, turbulence and temperature measurements pertinent to a description of the lower atmospheric dispersion potential. Preliminary results on six months' data have shown encouraging correlations between the acoustic sounder patterns and particularly the wind direction turbulence traces. (author)

Job Surfing: Move On to Move Up.

Science.gov (United States)

Martin, Justin

1997-01-01

Looks at the process of switching jobs and changing careers. Discusses when to consider options and make the move as well as the need to be flexible and open minded. Provides a test for determining the chances of promotion and when to move on. (JOW)

33 CFR 165.812 - Security Zones; Lower Mississippi River, Southwest Pass Sea Buoy to Mile Marker 96.0, New Orleans...

Science.gov (United States)

2010-07-01

... River, Southwest Pass Sea Buoy to Mile Marker 96.0, New Orleans, LA. 165.812 Section 165.812 Navigation..., Southwest Pass Sea Buoy to Mile Marker 96.0, New Orleans, LA. (a) Location. Within the Lower Mississippi... Lower Mississippi River mile marker 96.0 in New Orleans, Louisiana. These moving security zones...

The multiphase physics of sea ice: a review for model developers

Directory of Open Access Journals (Sweden)

E. C. Hunke

2011-11-01

Full Text Available Rather than being solid throughout, sea ice contains liquid brine inclusions, solid salts, microalgae, trace elements, gases, and other impurities which all exist in the interstices of a porous, solid ice matrix. This multiphase structure of sea ice arises from the fact that the salt that exists in seawater cannot be incorporated into lattice sites in the pure ice component of sea ice, but remains in liquid solution. Depending on the ice permeability (determined by temperature, salinity and gas content, this brine can drain from the ice, taking other sea ice constituents with it. Thus, sea ice salinity and microstructure are tightly interconnected and play a significant role in polar ecosystems and climate. As large-scale climate modeling efforts move toward "earth system" simulations that include biological and chemical cycles, renewed interest in the multiphase physics of sea ice has strengthened research initiatives to observe, understand and model this complex system. This review article provides an overview of these efforts, highlighting known difficulties and requisite observations for further progress in the field. We focus on mushy layer theory, which describes general multiphase materials, and on numerical approaches now being explored to model the multiphase evolution of sea ice and its interaction with chemical, biological and climate systems.

Meteorological Research Institute multivariate ocean variational estimation (MOVE) system: Some early results

Science.gov (United States)

Usui, Norihisa; Ishizaki, Shiro; Fujii, Yosuke; Tsujino, Hiroyuki; Yasuda, Tamaki; Kamachi, Masafumi

The Meteorological Research Institute multivariate ocean variational estimation (MOVE) System has been developed as the next-generation ocean data assimilation system in Japan Meteorological Agency. A multivariate three-dimensional variational (3DVAR) analysis scheme with vertical coupled temperature salinity empirical orthogonal function modes is adopted. The MOVE system has two varieties, the global (MOVE-G) and North Pacific (MOVE-NP) systems. The equatorial Pacific and western North Pacific are analyzed with assimilation experiments using MOVE-G and -NP, respectively. In each system, the salinity and velocity fields are well reproduced, even in cases without salinity data. Changes in surface and subsurface zonal currents during the 1997/98 El Niño event are captured well, and their transports are reasonably consistent with in situ observations. For example, the eastward transport in the upper layer around the equator has 70 Sv in spring 1997 and weakens in spring 1998. With MOVE-NP, the Kuroshio transport has 25 Sv in the East China Sea, and 40 Sv crossing the ASUKA (Affiliated Surveys of the Kuroshio off Cape Ashizuri) line south of Japan. The variations in the Kuroshio transports crossing the ASUKA line agree well with observations. The Ryukyu Current System has a transport ranging from 6 Sv east of Taiwan to 17 Sv east of Amami. The Oyashio transport crossing the OICE (Oyashio Intensive observation line off Cape Erimo) line south of Hokkaido has 14 Sv southwestward (near shore) and 11 Sv northeastward (offshore). In the Kuroshio Oyashio transition area east of Japan, the eastward transport has 41 Sv (32 36°N) and 12 Sv (36 39°N) crossing the 145°E line.

Estimating the Ocean Flow Field from Combined Sea Surface Temperature and Sea Surface Height Data

Science.gov (United States)

Stammer, Detlef; Lindstrom, Eric (Technical Monitor)

2002-01-01

This project was part of a previous grant at MIT that was moved over to the Scripps Institution of Oceanography (SIO) together with the principal investigator. The final report provided here is concerned only with the work performed at SIO since January 2000. The primary focus of this project was the study of the three-dimensional, absolute and time-evolving general circulation of the global ocean from a combined analysis of remotely sensed fields of sea surface temperature (SST) and sea surface height (SSH). The synthesis of those two fields was performed with other relevant physical data, and appropriate dynamical ocean models with emphasis on constraining ocean general circulation models by a combination of both SST and SSH data. The central goal of the project was to improve our understanding and modeling of the relationship between the SST and its variability to internal ocean dynamics, and the overlying atmosphere, and to explore the relative roles of air-sea fluxes and internal ocean dynamics in establishing anomalies in SST on annual and longer time scales. An understanding of those problems will feed into the general discussion on how SST anomalies vary with time and the extend to which they interact with the atmosphere.

Aerosol number size distributions over a coastal semi urban location: Seasonal changes and ultrafine particle bursts

Energy Technology Data Exchange (ETDEWEB)

Babu, S. Suresh, E-mail: s_sureshbabu@vssc.gov.in [Space Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram 695022 (India); Kompalli, Sobhan Kumar [Space Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram 695022 (India); Moorthy, K. Krishna [Centre for Atmospheric and Oceanic Sciences, Indian Institute of Science, Bangalore 560 012 (India)

2016-09-01

Number-size distribution is one of the important microphysical properties of atmospheric aerosols that influence aerosol life cycle, aerosol-radiation interaction as well as aerosol-cloud interactions. Making use of one-yearlong measurements of aerosol particle number-size distributions (PNSD) over a broad size spectrum (~ 15–15,000 nm) from a tropical coastal semi-urban location-Trivandrum (Thiruvananthapuram), the size characteristics, their seasonality and response to mesoscale and synoptic scale meteorology are examined. While the accumulation mode contributed mostly to the annual mean concentration, ultrafine particles (having diameter < 100 nm) contributed as much as 45% to the total concentration, and thus constitute a strong reservoir, that would add to the larger particles through size transformation. The size distributions were, in general, bimodal with well-defined modes in the accumulation and coarse regimes, with mode diameters lying in the range 141 to 167 nm and 1150 to 1760 nm respectively, in different seasons. Despite the contribution of the coarse sized particles to the total number concentration being meager, they contributed significantly to the surface area and volume, especially during transport of marine air mass highlighting the role of synoptic air mass changes. Significant diurnal variation occurred in the number concentrations, geometric mean diameters, which is mostly attributed to the dynamics of the local coastal atmospheric boundary layer and the effect of mesoscale land/sea breeze circulation. Bursts of ultrafine particles (UFP) occurred quite frequently, apparently during periods of land-sea breeze transitions, caused by the strong mixing of precursor-rich urban air mass with the cleaner marine air mass; the resulting turbulence along with boundary layer dynamics aiding the nucleation. These ex-situ particles were observed at the surface due to the transport associated with boundary layer dynamics. The particle growth rates from

Aerosol number size distributions over a coastal semi urban location: Seasonal changes and ultrafine particle bursts

International Nuclear Information System (INIS)

Babu, S. Suresh; Kompalli, Sobhan Kumar; Moorthy, K. Krishna

2016-01-01

Number-size distribution is one of the important microphysical properties of atmospheric aerosols that influence aerosol life cycle, aerosol-radiation interaction as well as aerosol-cloud interactions. Making use of one-yearlong measurements of aerosol particle number-size distributions (PNSD) over a broad size spectrum (~ 15–15,000 nm) from a tropical coastal semi-urban location-Trivandrum (Thiruvananthapuram), the size characteristics, their seasonality and response to mesoscale and synoptic scale meteorology are examined. While the accumulation mode contributed mostly to the annual mean concentration, ultrafine particles (having diameter < 100 nm) contributed as much as 45% to the total concentration, and thus constitute a strong reservoir, that would add to the larger particles through size transformation. The size distributions were, in general, bimodal with well-defined modes in the accumulation and coarse regimes, with mode diameters lying in the range 141 to 167 nm and 1150 to 1760 nm respectively, in different seasons. Despite the contribution of the coarse sized particles to the total number concentration being meager, they contributed significantly to the surface area and volume, especially during transport of marine air mass highlighting the role of synoptic air mass changes. Significant diurnal variation occurred in the number concentrations, geometric mean diameters, which is mostly attributed to the dynamics of the local coastal atmospheric boundary layer and the effect of mesoscale land/sea breeze circulation. Bursts of ultrafine particles (UFP) occurred quite frequently, apparently during periods of land-sea breeze transitions, caused by the strong mixing of precursor-rich urban air mass with the cleaner marine air mass; the resulting turbulence along with boundary layer dynamics aiding the nucleation. These ex-situ particles were observed at the surface due to the transport associated with boundary layer dynamics. The particle growth rates from

Physical climatology of Indonesian maritime continent: An outline to comprehend observational studies

Science.gov (United States)

Yamanaka, Manabu D.

2016-09-01

The Indonesian maritime continent (IMC) is a miniature of our land-sea coexisting planet Earth. Firstly, without interior activity, the Earth becomes an even-surfaced "aqua-planet" with both atmosphere and ocean flowing almost zonally, and solar differential heating generates (global thermal tides and) Hadley's meridional circulations with the inter-tropical convergence zone (ITCZ) along the equator as observed actually over the open (Indian and Pacific) oceans on the both sides of the IMC. The ITCZ involves intraseasonal variations or super cloud clusters moving eastward with hierarchical substructures moving also westward. Secondly, the lands and seas over the actual Earth have been keeping the area ratio of 3:7 (similar to that of islands and inland/surrounding seas in the IMC), but their displacements have produced the IMC near the equator, which turns equatorial Pacific easterly ocean current northward (Kuroshio) and reflects equatorial oceanic waves that affect coupled ocean-atmosphere interannual variations such as ENSO and IOD, or displacements of Walker's zonal circulations. Thirdly, because the IMC consists of many large/small islands with very long coastlines, many narrow straits control the global (Pacific to Indian) ocean circulation, and the land-sea heat capacity contrasts along the coastlines generate the world's largest rainfall with diurnal cycles (sea-land breeze circulations). The diurnal cycles are dominant even in the rainy season (austral summer in Jawa and Bali), because rainfall-induced sprinkler-like land cooling reverses the trans-coastal temperature gradient before sunrise, and subsequent clear sky on land until around noon provides solar heating dependent on season. These processes lead to rapid land/hydrosphere-atmosphere water exchange, local air pollutant washout, and transequatorial boreal winter monsoon (cold surge). In El Niño years, for example, the cooler sea-surface temperature suppresses the morning coastal-sea rainfall, and

An observational study of the evolution of the atmospheric boundary-layer over Cabo Frio, Brazil

Directory of Open Access Journals (Sweden)

S. H. Franchito

2007-08-01

Full Text Available The effect of coastal upwelling on the evolution of the atmospheric boundary layer (ABL in Cabo Frio (Brazil is investigated. For this purpose, radiosounding data collected in two experiments made during the austral summer (upwelling case and austral winter (no upwelling case are analysed. The results show that during the austral summer, cold waters that crop up near the Cabo Frio coast favour the formation of an atmospheric stable layer, which persists during the upwelling episode. Due to the low SSTs, the descending branch of the sea-breeze circulation is located close to the coast, inhibiting the development of a mixed layer mainly during the day. At night, with the reduction of the land-sea thermal contrast the descending motion is weaker, allowing a vertical mixing. The stable ABL favours the formation of a low level jet, which may also contribute to the development of a nocturnal atmospheric mixed layer. During the austral winter, due to the higher SSTs observed near the coast, the ABL is less stable compared with that in the austral summer. Due to warming, a mixed layer is observed during the day. The observed vertical profiles of the zonal winds show that the easterlies at low levels are stronger in the austral summer, indicating that the upwelling modulates the sea-breeze signal, thus confirming model simulations.

Relation between aerosol sources and meteorological parameters for inhalable atmospheric particles in Sao Paulo City, Brazil

Science.gov (United States)

Andrade, Fatima; Orsini, Celso; Maenhaut, Willy

Stacked filter units were used to collect atmospheric particles in separate coarse and fine fractions at the Sao Paulo University Campus during the winter of 1989. The samples were analysed by particle-induced X-ray emission (PIXE) and the data were subjected to an absolute principal component analysis (APCA). Five sources were identified for the fine particles: industrial emissions, which accounted for 13% of the fine mass; emissions from residual oil and diesel, explaining 41%; resuspended soil dust, with 28%; and emissions of Cu and of Mg, together with 18%. For the coarse particles, four sources were identified: soil dust, accounting for 59% of the coarse mass; industrial emissions, with 19%; oil burning, with 8%; and sea salt aerosol, with 14% of the coarse mass. A data set with various meteorological parameters was also subjected to APCA, and a correlation analysis was performed between the meteorological "absolute principal component scores" (APCS) and the APCS from the fine and coarse particle data sets. The soil dust sources for the fine and coarse aerosol were highly correlated with each other and were anticorrelated with the sea breeze component. The industrial components in the fine and coarse size fractions were also highly positively correlated. Furthermore, the industrial component was related with the northeasterly wind direction and, to a lesser extent, with the sea breeze component.

Role of the Atmospheric General Circulation on the Temporal Variability of the Aerosol Distribution over Dakar (Senegal)

Science.gov (United States)

Senghor, Habib; Machu, Eric; Hourdin, Frederic; Thierno Gaye, Amadou; Gueye, Moussa; Simina Drame, Mamadou

2016-04-01

The natural or anthropogenic aerosols play an important role on the climate system and the human health through their optical and physical properties. To evaluate the potential impacts of these aerosols, it is necessary to better understand their temporal variability in relation with the atmospheric ciculation. Some previous case studies have pointed out the influence of the sea-breeze circulation on the vertical distribution of the aerosols along the Western African coast. In the present work, Lidar (Ceilometer CL31; located at Dakar) data are used for the period 2012-2014 together with Level-3 data from CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) between 2007 and 2014 for studying the seasonal cycle of the vertical distribution of aerosols over Dakar (17.5°W, 14.74°N). Both instruments show strong seasonal variability with a maximum of aerosol occurrence in May over Dakar. The CL31 shows a crucial impact of sea-breeze circulation on the diurnal cycle of the Mixed Atmospheric Boundary Layer and a strong dust signal in spring in the nocturnal low-level jet (LLJ) located between 500 and 1000 m altitudes over Dakar.

Test of a non-physical barrier consisting of light, sound, and bubble screen to block upstream movement of sea lamprey in an experimental raceway

Science.gov (United States)

Miehls, Scott M.; Johnson, Nicholas S.; Hrodey, Pete J.

2017-01-01

Control of the invasive Sea Lamprey Petromyzon marinus is critical for management of commercial and recreational fisheries in the Laurentian Great Lakes. Use of physical barriers to block Sea Lampreys from spawning habitat is a major component of the control program. However, the resulting interruption of natural streamflow and blockage of nontarget species present substantial challenges. Development of an effective nonphysical barrier would aid the control of Sea Lampreys by eliminating their access to spawning locations while maintaining natural streamflow. We tested the effect of a nonphysical barrier consisting of strobe lights, low-frequency sound, and a bubble screen on the movement of Sea Lampreys in an experimental raceway designed as a two-choice maze with a single main channel fed by two identical inflow channels (one control and one blocked). Sea Lampreys were more likely to move upstream during trials when the strobe light and low-frequency sound were active compared with control trials and trials using the bubble screen alone. For those Sea Lampreys that did move upstream to the confluence of inflow channels, no combination of stimuli or any individual stimulus significantly influenced the likelihood that Sea Lampreys would enter the blocked inflow channel, enter the control channel, or return downstream.

Daytime avoidance of chemosensory alarm cues by adult sea lamprey (Petromyzon marinus)

Science.gov (United States)

Di Rocco, Richard; Belanger, Cowan; Imre, István; Brown, Grant; Johnson, Nicholas S.

2014-01-01

Sea lamprey (Petromyzon marinus) avoid damage-released and predator chemosensory cues at night, but their response to these cues during the day is unknown. Here, we explored (i) whether sea lamprey avoid these cues during the day and (ii) the effect of water temperature on the avoidance of chemosensory alarm cues in two diurnal laboratory experiments. We hypothesized that daytime activity would be temperature-dependent and that only sea lamprey vulnerable to predation (i.e., not hiding) would behaviourally respond to chemosensory alarm cues. Ten groups of ten sea lamprey were exposed to one of a variety of potential chemosensory cues. The experiments were conducted over a range of temperatures to quantify the effect of temperature on avoidance behaviour. Consistent with our hypothesis, a higher proportion of animals were active during daytime as water temperature increased. Moving sea lamprey showed an avoidance response to 2-phenylethylamine (a compound found in mammalian urine) and human saliva once water temperatures had risen to mean (±SD) = 13.7 (±1.4) °C. Resting and hiding sea lamprey did not show an avoidance response to any of the experimental stimuli.

Moving related to separation : who moves and to what distance

NARCIS (Netherlands)

Mulder, Clara H.; Malmberg, Gunnar

We address the issue of moving from the joint home on the occasion of separation. Our research question is: To what extent can the occurrence of moves related to separation, and the distance moved, be explained by ties to the location, resources, and other factors influencing the likelihood of

Dead Sea evaporation by eddy covariance measurements vs. aerodynamic, energy budget, Priestley-Taylor, and Penman estimates

Science.gov (United States)

Metzger, Jutta; Nied, Manuela; Corsmeier, Ulrich; Kleffmann, Jörg; Kottmeier, Christoph

2018-02-01

The Dead Sea is a terminal lake, located in an arid environment. Evaporation is the key component of the Dead Sea water budget and accounts for the main loss of water. So far, lake evaporation has been determined by indirect methods only and not measured directly. Consequently, the governing factors of evaporation are unknown. For the first time, long-term eddy covariance measurements were performed at the western Dead Sea shore for a period of 1 year by implementing a new concept for onshore lake evaporation measurements. To account for lake evaporation during offshore wind conditions, a robust and reliable multiple regression model was developed using the identified governing factors wind velocity and water vapour pressure deficit. An overall regression coefficient of 0.8 is achieved. The measurements show that the diurnal evaporation cycle is governed by three local wind systems: a lake breeze during daytime, strong downslope winds in the evening, and strong northerly along-valley flows during the night. After sunset, the strong winds cause half-hourly evaporation rates which are up to 100 % higher than during daytime. The median daily evaporation is 4.3 mm d-1 in July and 1.1 mm d-1 in December. The annual evaporation of the water surface at the measurement location was 994±88 mm a-1 from March 2014 until March 2015. Furthermore, the performance of indirect evaporation approaches was tested and compared to the measurements. The aerodynamic approach is applicable for sub-daily and multi-day calculations and attains correlation coefficients between 0.85 and 0.99. For the application of the Bowen ratio energy budget method and the Priestley-Taylor method, measurements of the heat storage term are inevitable on timescales up to 1 month. Otherwise strong seasonal biases occur. The Penman equation was adapted to calculate realistic evaporation, by using an empirically gained linear function for the heat storage term, achieving correlation coefficients between 0

Different migration patterns of sea urchin and mouse sperm revealed by a microfluidic chemotaxis device.

Directory of Open Access Journals (Sweden)

Haixin Chang

Full Text Available Chemotaxis refers to a process whereby cells move up or down a chemical gradient. Sperm chemotaxis is known to be a strategy exploited by marine invertebrates such as sea urchins to reach eggs efficiently in moving water. Less is understood about how or whether chemotaxis is used by mammalian sperm to reach eggs, where fertilization takes place within the confinement of a reproductive tract. In this report, we quantitatively assessed sea urchin and mouse sperm chemotaxis using a recently developed microfluidic model and high-speed imaging. Results demonstrated that sea urchin Arbacia punctulata sperm were chemotactic toward the peptide resact with high chemotactic sensitivity, with an average velocity Vx up the chemical gradient as high as 20% of its average speed (238 μm/s, while mouse sperm displayed no statistically significant chemotactic behavior in progesterone gradients, which had been proposed to guide mammalian sperm toward eggs. This work demonstrates the validity of a microfluidic model for quantitative sperm chemotaxis studies, and reveals a biological insight that chemotaxis up a progesterone gradient may not be a universal strategy for mammalian sperm to reach eggs.

Wind Forecasting for Yacht Racing at the 1991 Pan American Games.

Science.gov (United States)

Powell, Mark D.

1993-01-01

The U.S. Sailing Team competed successfully at the 1991 Pan American Games despite having no previous experience with the sailing conditions off Havana, Cuba. One of the key factors in the team's success was meteorological support in the form of wind climate analysis; application of sea breeze forecasting typical of the south Florida area, modified by tropical weather systems; and effective preregatta briefing.

Observed 1970-2005 cooling of summer daytime temperatures in coastal California

Energy Technology Data Exchange (ETDEWEB)

Lebassi, B.; Gonzalez, J.; Fabris, D.; Maurer, E.; Miller, N.; Milesi, C.; Bornstein, R.

2009-05-15

The study evaluated 1948-2004 summer (JJA) mean monthly air temperatures for two California air basins: SoCAB and SFBA. The study focuses on the more rapid post-1970 warming period, and its daily T{sub min} and T{sub max} values were used to produce average monthly values and spatial distributions of trends for each air basins. Additional analyses included T{sub D} values at two NWS sites, SSTs, NCEP reanalysis sea-level pressures, and GCM T{sub ave}-values. Results for all California COOP sites together showed increased JJA T{sub ave}-values; asymmetric warming, as T{sub min}-values increase faster than T{sub max}-values; and thus decreased DTR values. The spatial distribution of observed SoCAB and SFBA T{sub max} values exhibited a complex pattern, with cooling in low-elevation coastal-areas open to marine air penetration and warming at inland areas. Results also showed that decreased DTR values in the valleys arose from small increases at 'inland' sites combined with large decreases at 'coastal' sites. Previous studies suggest that cooling JJA T{sub max}-values in coastal California were due to increased irrigation, coastal upwelling, or cloud cover, while the current hypothesis is that they arises from GHG-induced global-warming of 'inland' areas, which results in increased sea breeze flow activity. Sea level pressure trends showed increases in the oceanic Pacific High and decreases in the central-California Thermal Low. The corresponding gradient thus showed a trend of 0.02 hPa 100-km{sup -1} decade{sup -1}, supportive of the hypothesis of increased sea breeze activity. Trends in T{sub D} values showed a larger value at coastal SFO than at inland SEC, which indicative of increased sea breeze activity; calculated SST trends (0.15 C decade{sup -1}) could also have increase T{sub D}-values. GCM model Tave-values showed warming that decreases from 0.13 C decade{sup -1} at inland California to 0.08 C decade{sup -1} at coastal areas

Measuring the Rate of Change in Sea Level and Its Adherence to USACE Sea Level Rise Planning Scenarios Using Timeseries Metrics

Science.gov (United States)

White, K. D.; Huang, N.; Huber, M.; Veatch, W.; Moritz, H.; Obrien, P. S.; Friedman, D.

2017-12-01

In 2013, the United States Army Corps of Engineers (USACE) issued guidance for all Civil Works activities to incorporate the effects of sea level change as described in three distinct planning scenarios.[1] These planning scenarios provided a useful framework to incorporate these effects into Civil Works activities, but required the manual calculation of these scenarios for a given gage and set of datum. To address this need, USACE developed the Sea Level Change Curve Calculator (SLCCC) in 2014 which provided a "simple, web-based tool to provide repeatable analytical results."[2]USACE has been developing a successor to the SLCCC application which retains the same, intuitive functionality to calculate these planning scenarios, but it also allows the comparison of actual sea level change between 1992 and today against the projections, and builds on the user's ability to understand the rate of change using a variety of timeseries metrics (e.g. moving averages, trends) and related visualizations. These new metrics help both illustrate and measure the complexity and nuances of sea level change. [1] ER 1000-2-8162. http://www.publications.usace.army.mil/Portals/76/Publications/EngineerRegulations/ER_1100-2-8162.pdf. [2] SLCC Manual. http://www.corpsclimate.us/docs/SLC_Calculator_Manual_2014_88.pdf.

Forced wave induced by an atmospheric pressure disturbance moving towards shore

Science.gov (United States)

Chen, Yixiang; Niu, Xiaojing

2018-05-01

Atmospheric pressure disturbances moving over a vast expanse of water can induce different wave patterns, which can be determined by the Froude number Fr. Generally, Fr = 1 is a critical value for the transformation of the wave pattern and the well-known Proudman resonance happens when Fr = 1. In this study, the forced wave induced by an atmospheric pressure disturbance moving over a constant slope from deep sea to shore is numerically investigated. The wave pattern evolves from a concentric-circle type into a triangular type with the increase of the Froude number, as the local water depth decreases, which is in accord with the analysis in the unbounded flat-bottom cases. However, a hysteresis effect has been observed, which implies the obvious amplification of the forced wave induced by a pressure disturbance can not be simply predicted by Fr = 1. The effects of the characteristic parameters of pressure disturbances and slope gradient have been discussed. The results show that it is not always possible to observe significant peak of the maximum water elevation before the landing of pressure disturbances, and a significant peak can be generated by a pressure disturbance with small spatial scale and fast moving velocity over a milder slope. Besides, an extremely high run-up occurs when the forced wave hits the shore, which is an essential threat to coastal security. The results also show that the maximum run-up is not monotonously varying with the increase of disturbance moving speed and spatial scale. There exists a most dangerous speed and scale which may cause disastrous nearshore surge.

Move up,Move out

Institute of Scientific and Technical Information of China (English)

Guo Yan

2007-01-01

@@ China has already become the world's largest manufacturer of cement,copper and steel.Chinese producers have moved onto the world stage and dominated the global consumer market from textiles to electronics with amazing speed and efficiency.

Fine-scale pathways used by adult sea lampreys during riverine spawning migrations

Science.gov (United States)

Holbrook, Christopher; Bergstedt, Roger A.; Adams, Noah S.; Hatton, Tyson; McLaughlin, Robert L.

2015-01-01

Better knowledge of upstream migratory patterns of spawning Sea Lampreys Petromyzon marinus, an invasive species in the Great Lakes, is needed to improve trapping for population control and assessment. Although trapping of adult Sea Lampreys provides the basis for estimates of lake-wide abundance that are used to evaluate the Sea Lamprey control program, traps have only been operated at dams due to insufficient knowledge of Sea Lamprey behavior in unobstructed channels. Acoustic telemetry and radiotelemetry were used to obtain movement tracks for 23 Sea Lampreys in 2008 and 18 Sea Lampreys in 2009 at two locations in the Mississagi River, Ontario. Cabled hydrophone arrays provided two-dimensional geographic positions from acoustic transmitters at 3-s intervals; depth-encoded radio tag detections provided depths. Upstream movements occurred at dusk or during the night (2015–0318 hours). Sea Lampreys were closely associated with the river bottom and showed some preference to move near banks in shallow glide habitats, suggesting that bottom-oriented gears could selectively target adult Sea Lampreys in some habitats. However, Sea Lampreys were broadly distributed across the river channel, suggesting that the capture efficiency of nets and traps in open channels would depend heavily on the proportion of the channel width covered. Lack of vertical movements into the water column may have reflected lamprey preference for low water velocities, suggesting that energy conservation was more beneficial for lampreys than was vertical searching in rivers. Improved understanding of Sea Lamprey movement will assist in the development of improved capture strategies for their assessment and control in the Great Lakes.

Sea-level rise risks to coastal cities

Science.gov (United States)

Nicholls, Robert J.

2017-04-01

Understanding the consequence of sea-level rise for coastal cities has long lead times and huge political implications. Civilisation has emerged and developed during a period of several thousand years during which in geological terms sea level has been unusually stable. We have now moved out of this period and the challenge will be to develop a long-term proactive assessment approach to manage this challenge. In 2005 there were 136 coastal cities with a population exceeding one million people and a collective population of 400 million people. All these coastal cities are threatened by flooding from the sea to varying degrees and these risks are increasing due to growing exposure (people and assets), rising sea levels due to climate change, and in some cities, significant coastal subsidence due to human agency (drainage and groundwater withdrawals from susceptible soils). In these cities we wish to avoid major flood events, with associated damage and potentially deaths and ultimately decline of the cities. Flood risks grow with sea-level rise as it raises extreme sea levels. As sea levels continue to rise, protection will have to be progressively upgraded. Even with this, the magnitude of losses when flood events do occur would increase as coastal cities expand, and water depths and hence unit damage increase with sea-level rise/subsidence. This makes it critical to also prepare for larger coastal flood disasters than we experience today and raises questions on the limits to adaptation. There is not an extensive literature or significant empirical information on the limits to adaptation in coastal cities. These limits are not predictable in a formal sense - while the rise in mean sea level raises the likelihood of a catastrophic flood, extreme events are what cause damage and trigger a response, be it abandonment, a defence upgrade or something else. There are several types of potential limits that could be categorised into three broad types: • Physical

Role of moving planes and moving spheres following Dupin cyclides

KAUST Repository

Jia, Xiaohong

2014-03-01

We provide explicit representations of three moving planes that form a μ-basis for a standard Dupin cyclide. We also show how to compute μ-bases for Dupin cyclides in general position and orientation from their implicit equations. In addition, we describe the role of moving planes and moving spheres in bridging between the implicit and rational parametric representations of these cyclides. © 2014 Elsevier B.V.

Role of moving planes and moving spheres following Dupin cyclides

KAUST Repository

Jia, Xiaohong

2014-01-01

We provide explicit representations of three moving planes that form a μ-basis for a standard Dupin cyclide. We also show how to compute μ-bases for Dupin cyclides in general position and orientation from their implicit equations. In addition, we describe the role of moving planes and moving spheres in bridging between the implicit and rational parametric representations of these cyclides. © 2014 Elsevier B.V.

Automatic Moving Object Segmentation for Freely Moving Cameras

Directory of Open Access Journals (Sweden)

Yanli Wan

2014-01-01

Full Text Available This paper proposes a new moving object segmentation algorithm for freely moving cameras which is very common for the outdoor surveillance system, the car build-in surveillance system, and the robot navigation system. A two-layer based affine transformation model optimization method is proposed for camera compensation purpose, where the outer layer iteration is used to filter the non-background feature points, and the inner layer iteration is used to estimate a refined affine model based on the RANSAC method. Then the feature points are classified into foreground and background according to the detected motion information. A geodesic based graph cut algorithm is then employed to extract the moving foreground based on the classified features. Unlike the existing global optimization or the long term feature point tracking based method, our algorithm only performs on two successive frames to segment the moving foreground, which makes it suitable for the online video processing applications. The experiment results demonstrate the effectiveness of our algorithm in both of the high accuracy and the fast speed.

Moving event and moving participant in aspectual conceptions

Directory of Open Access Journals (Sweden)

Izutsu Katsunobu

2016-06-01

Full Text Available This study advances an analysis of the event conception of aspectual forms in four East Asian languages: Ainu, Japanese, Korean, and Ryukyuan. As earlier studies point out, event conceptions can be divided into two major types: the moving-event type and the moving-participant type, respectively. All aspectual forms in Ainu and Korean, and most forms in Japanese and Ryukyuan are based on that type of event conception. Moving-participant oriented Ainu and movingevent oriented Japanese occupy two extremes, between which Korean and Ryukyuan stand. Notwithstanding the geographical relationships among the four languages, Ryukyuan is closer to Ainu than to Korean, whereas Korean is closer to Ainu than to Japanese.

Odor-conditioned rheotaxis of the sea lamprey: modeling, analysis and validation

International Nuclear Information System (INIS)

Choi, Jongeun; Jeon, Soo; Johnson, Nicholas S; Brant, Cory O; Li, Weiming

2013-01-01

Mechanisms for orienting toward and locating an odor source are sought in both biology and engineering. Chemical ecology studies have demonstrated that adult female sea lamprey show rheotaxis in response to a male pheromone with dichotomous outcomes: sexually mature females locate the source of the pheromone whereas immature females swim by the source and continue moving upstream. Here we introduce a simple switching mechanism modeled after odor-conditioned rheotaxis for the sea lamprey as they search for the source of a pheromone in a one-dimensional riverine environment. In this strategy, the females move upstream only if they detect that the pheromone concentration is higher than a threshold value and drifts down (by turning off control action to save energy) otherwise. In addition, we propose various uncertainty models such as measurement noise, actuator disturbance, and a probabilistic model of a concentration field in turbulent flow. Based on the proposed model with uncertainties, a convergence analysis showed that with this simplistic switching mechanism, the lamprey converges to the source location on average in spite of all such uncertainties. Furthermore, a slightly modified model and its extensive simulation results explain the behaviors of immature female lamprey near the source location. (paper)

North Sea oil and gas: a geographical perspective

Energy Technology Data Exchange (ETDEWEB)

Chapman, K

1976-01-01

Only ten years after the first rig moved into position, British oil has been piped ashore from the North Sea and, by 1980, will be making a substantial contribution to UK energy supplies. The discovery of natural gas in 1967--for initially gas was the primary objective--has transformed the gas supply so that 90% of the UK's needs already come from the North Sea. The speed and concentration of exploration pinpoints the vital importance of this new energy source. Until now the major oil 'pipeline' in the world has been led between the Middle East and Western Europe, so this new energy source has far reaching implications, both political and economic. Keith Chapman examines these implications starting from events in the North Sea itself; the geological background, agreement on the division of the North Sea, relations between oil companies, and government embodied in offshore mining legislation. The latter part of the book concentrates on the onshore repercussions of offshore activities; how North Sea oil fits into the international oil system, the various options open for its utilisation, the attitude of the EEC towards Scottish-based resources, government policy for the North coast of Scotland--an area which planners classed as ''peripheral'' but which must now accommodate extensive support facilities and service industries for the oil sites. There is also the question of relations between national and commercial interests--government versus the giant multi-national companies which took the initial gamble in the North Sea and are now responsible for the development of a resource vital to the economic well-being of Western Europe.

Fate of microplastics and mesoplastics carried by surface currents and wind waves: A numerical model approach in the Sea of Japan.

Science.gov (United States)

Iwasaki, Shinsuke; Isobe, Atsuhiko; Kako, Shin'ichiro; Uchida, Keiichi; Tokai, Tadashi

2017-08-15

A numerical model was established to reproduce the oceanic transport processes of microplastics and mesoplastics in the Sea of Japan. A particle tracking model, where surface ocean currents were given by a combination of a reanalysis ocean current product and Stokes drift computed separately by a wave model, simulated particle movement. The model results corresponded with the field survey. Modeled results indicated the micro- and mesoplastics are moved northeastward by the Tsushima Current. Subsequently, Stokes drift selectively moves mesoplastics during winter toward the Japanese coast, resulting in increased contributions of mesoplastics south of 39°N. Additionally, Stokes drift also transports micro- and mesoplastics out to the sea area south of the subpolar front where the northeastward Tsushima Current carries them into the open ocean via the Tsugaru and Soya straits. Average transit time of modeled particles in the Sea of Japan is drastically reduced when including Stokes drift in the model. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

An overview of sea otter studies

Science.gov (United States)

Ballachey, Brenda E.; Bodkin, James L.; DeGange, Anthony R.; Loughlin, Thomas R.

1994-01-01

The Exxron Valdez oil spill (EVOS) on 24 March 1989 threatened extensive areas of prime sea otter (Enhydra lutris) habitat along the coasts of south-central Alaska. The spill occurred in northeastern Prince William Sound (PWS), and oil moved rapidly south and west through PWS into the Gulf of Alaska. Much of the coastline of western PWS was heavily oiled, and the slick eventually spread as far southwest as Kodiak Island and the Alaska Peninsula (Galt and Payton 1990; Morris and Loughlin, Chapter 1). All coastal waters affected by the spill were inhabited by sea otters.Concern for the survival of sea otters following the oil spill was immediate and well founded. Sea otters are particularly vulnerable to oil contamination because they rely on pelage rather than blubber for insulation, and oiling drastically reduces the insulative value of the fur (Costa and Kooyman 1982; Siniff et al. 1982; Geraci and Williams 1990). Within days of the spill, recovery of oiled live otters and carcasses began. During the several months following the spill, sea otters became symbolic of the mortality associated with the spilled oil, and of the hope for rescue and recovery of injured wildlife (Batten 1990).An extensive sea otter rescue and rehabilitation effort was mounted in the weeks and months following the spill. Handling and treatment of the captive sea otters posed an enormous and difficult challenge, given the large number of otters held at the facilities and minimal prior experience in caring for oiled sea otters. Rehabilitation of sea otters was a separate effort from the postspill studies designed to evaluate injury to the otter populations and is not addressed in this chapter only as it relates to evaluation of damage assessment studies. Detailed information on the rehabilitation effort is presented in Bayha and Kormendy (1990) and Williams and Davis (1990).Sea otters retained a high profile in the Natural Resource Damage Assessment (NRDA) studies largely because the initial

Maritime Strike Operations Tactics Development and Evaluation, Eglin Air Force Base, Florida. Final Environmental Assessment

Science.gov (United States)

2013-05-01

Strike missions would be delayed or rescheduled if the sea state is greater than moderate breeze~ winds 11 to 16 knots; wave height 3.5 to 6 feet...including but not limited to migration, surfacing, nursing , breeding, feeding, or sheltering, to a point where such behavioral patterns are abandoned...users of the surface and the offshore nature of EGTTR waters, rescheduling of tests rarely occurs. Affected Environment and Safety/Restricted Access

Investigation of local meteorological events and their relationship with ozone and aerosols during an ESCOMPTE photochemical episode

OpenAIRE

Augustin , P.; Delbarre , H.; Lohou , F.; Campistron , B.; Puygrenier , V.; Cachier , H.; Lombardo , T.

2006-01-01

The international ESCOMPTE campaign, which took place in summer 2001 in the most highly polluted French region, was devoted to validate air pollution prediction models. Surface and remote sensing instruments (Lidar, Radar and Sodar) were deployed over the Marseille area, along the Mediterranean coast, in order to investigate the fine structure of the sea-breeze circulation and its relationship with the pollutant concentrations.

The geographical situation of the Marseille ...

Convection anomalies associated with warm eddy at the coastal area

Science.gov (United States)

Shi, R.; Wang, D.

2017-12-01

A possible correlation between a warm eddy and thunderstorms and convective precipitations are investigated at the coastal area in the northwestern South China Sea. Compared to the climatological mean in August from 2006 to 2013, an extreme enhancement of thunderstorm activities and precipitation rate are identified at the southern offshore area of Hainan island in August 2010 when a strong and long-live warm eddy was observed near the coastline at the same time. The 3 hourly satellite data (TRMM) indicate that the nocturnal convections is strong offshore and that could be responsible for the extreme positive anomalies of thunderstorms and rainfall in August 2010. The TRMM data also show a small reduction of thunderstorm activities and rainfall on the island in the afternoon. Meanwhile, the Weather Research and Forecasting (WRF) model was applied to simulate the change of rainfall in August 2010. The WRF simulation of rainfall rate is comparable with the observation results while there is some difference in the spatial distribution. The WRF simulation successfully captured the strong offshore rainfall and the diurnal variation of rainfall in August 2010. The WRF simulation indicated that the different convergence induced by sea/land breeze could be one essential reason for the adjustment of thunderstorms and rainfall in 2010. The substantial connection between sea/land breeze and upper layer heat content modified by the warm eddy is still on ongoing and will be reported in the future work.

Sea level during storm surges as seen in tide-gauge records along the east coast of India

Digital Repository Service at National Institute of Oceanography (India)

Sundar, D.; Shankar, D.; Shetye, S.R.

and crossed the north Orissa coast later that day; it weakened and moved westward subsequent to landfall. Sea-level variations due to surges triggered by storm winds form a noise superimposed on the highly periodic tides, which have astronomical origins.... In the next section we describe the analysis used to 1326 CURRENT SCIENCE, VOL. 77, NO. 10, 25 NOVEMBER 1999 COMPUTATIONAL ENGINEERING SCIENCE Figure 1b. Astronomical tide and dehyphenminustided sea level during Event 1. The dark blue vertical lines...

Chinese Assertiveness in the South China Sea and Southeast Asian Responses

Directory of Open Access Journals (Sweden)

Carlyle A. Thayer

2011-01-01

Full Text Available This article reviews Chinese assertive behaviour towards the Philippines and Vietnam over South China Sea issues in 2011. The article compares and contrasts Chinese diplomatic behaviour in the period before and after the adoption by ASEAN member states and China of Guidelines for the Implementation the Declaration on Conduct of Parties in the South China Sea in July. In the first period China aggressively asserted its claims to sovereignty by interfering with commercial fishing and oil exploration activities of vessels operating in the Exclusive Economic Zones of Vietnam and the Philippines. Both states resisted Chinese actions. The Philippines allocated increased funding for defence modernization, lobbied ASEAN states and shored up its alliance with the United States. Vietnam too protested Chinese action and undertook symbolic steps to defend national sovereignty. In the second period all states moved to contain South China Sea tensions from affecting their larger bilateral relations. It remains to be seen, however, if proposed confidence building measures will ameliorate Chinese assertiveness.

Sea level trends in Southeast Asian seas

Science.gov (United States)

Strassburg, M. W.; Hamlington, B. D.; Leben, R. R.; Manurung, P.; Lumban Gaol, J.; Nababan, B.; Vignudelli, S.; Kim, K.-Y.

2015-05-01

Southeast Asian seas span the largest archipelago in the global ocean and provide a complex oceanic pathway connecting the Pacific and Indian oceans. The Southeast Asian sea regional sea level trends are some of the highest observed in the modern satellite altimeter record that now spans almost 2 decades. Initial comparisons of global sea level reconstructions find that 17-year sea level trends over the past 60 years exhibit good agreement with decadal variability associated with the Pacific Decadal Oscillation and related fluctuations of trade winds in the region. The Southeast Asian sea region exhibits sea level trends that vary dramatically over the studied time period. This historical variation suggests that the strong regional sea level trends observed during the modern satellite altimeter record will abate as trade winds fluctuate on decadal and longer timescales. Furthermore, after removing the contribution of the Pacific Decadal Oscillation (PDO) to sea level trends in the past 20 years, the rate of sea level rise is greatly reduced in the Southeast Asian sea region. As a result of the influence of the PDO, the Southeast Asian sea regional sea level trends during the 2010s and 2020s are likely to be less than the global mean sea level (GMSL) trend if the observed oscillations in wind forcing and sea level persist. Nevertheless, long-term sea level trends in the Southeast Asian seas will continue to be affected by GMSL rise occurring now and in the future.

Source water quality shaping different fouling scenarios in a full-scale desalination plant at the Red Sea

KAUST Repository

Khan, Muhammad; Manes, Carmem Lara De O; Aubry, Cyril; Croue, Jean-Philippe

2013-01-01

produced at a seawater RO desalination plant installed on a floating mobile barge. The plant was moved along the coastline of the Red Sea in Saudi Arabia. The two locations where the barge was anchored showed different water quality. At the second location

A comparison of moving object detection methods for real-time moving object detection

Science.gov (United States)

Roshan, Aditya; Zhang, Yun

2014-06-01

Moving object detection has a wide variety of applications from traffic monitoring, site monitoring, automatic theft identification, face detection to military surveillance. Many methods have been developed across the globe for moving object detection, but it is very difficult to find one which can work globally in all situations and with different types of videos. The purpose of this paper is to evaluate existing moving object detection methods which can be implemented in software on a desktop or laptop, for real time object detection. There are several moving object detection methods noted in the literature, but few of them are suitable for real time moving object detection. Most of the methods which provide for real time movement are further limited by the number of objects and the scene complexity. This paper evaluates the four most commonly used moving object detection methods as background subtraction technique, Gaussian mixture model, wavelet based and optical flow based methods. The work is based on evaluation of these four moving object detection methods using two (2) different sets of cameras and two (2) different scenes. The moving object detection methods have been implemented using MatLab and results are compared based on completeness of detected objects, noise, light change sensitivity, processing time etc. After comparison, it is observed that optical flow based method took least processing time and successfully detected boundary of moving objects which also implies that it can be implemented for real-time moving object detection.

A Case Study On the Relative Influence of Free Tropospheric Subsidence, Long Range Transport and Local Production in Modulating Ozone Concentrations over Qatar

Science.gov (United States)

Ayoub, Mohammed; Ackermann, Luis; Fountoukis, Christos; Gladich, Ivan

2016-04-01

The Qatar Environment and Energy Research Institute (QEERI) operates a network of air quality monitoring stations (AQMS) around the Doha metropolitan area and an ozonesonde station with regular weekly launches and occasional higher frequency launch experiments (HFLE). Six ozonesondes were launched at 0700 LT/0400 UTC and 1300 LT/1000 UTC over a three day period between 10-12 September, 2013. We present the analysis of the ozonesonde data coupled with regional chemical transport modeling over the same time period using WRF-Chem validated against both the ozonesonde and surface AQMS measurements. The HFLE and modeling show evidence of both subsidence and transboundary transport of ozone during the study period, coupled with a strong sea breeze circulation on the 11th of September resulting in elevated ozone concentrations throughout the boundary layer. The development of the sea breeze during the course of the day and influence of the early morning residual layer versus daytime production is quantified. The almost complete titration of ozone in the morning hours of 11 September, 2013 is attributed to local vehicular emissions of NOx and stable atmospheric conditions prevailing over the Doha area. The relative contribution of long range transport of ozone along the Arabian Gulf coast and local urban emissions are discussed.

Response of the Atmospheric Boundary Layer and Soil Layer to a High Altitude, Dense Aerosol Cover.

Science.gov (United States)

Garratt, J. R.; Pittock, A. B.; Walsh, K.

1990-01-01

The response of the atmospheric boundary layer to the appearance of a high-altitude smoke layer has been investigated in a mesoscale numerical model of the atmosphere. Emphasis is placed on the changes in mean boundary-layer structure and near-surface temperatures when smoke of absorption optical depth (AOD) in the, range 0 to 1 is introduced. Calculations have been made at 30°S, for different soil thermal properties and degrees of surface wetness, over a time period of several days during which major smoke-induced cooling occurs. The presence of smoke reduces the daytime mixed-layer depth and, for large enough values of AOD, results in a daytime surface inversion with large cooling confined to heights of less than a few hundred meters. Smoke-induced reductions in daytime soil and air temperatures of several degrees are typical, dependent critically upon soil wetness and smoke AOD. Locations near the coast experience reduced cooling whenever there is a significant onshore flow related to a sea breeze (this would also be the case with a large-scale onshore flow). The sea breeze itself disappears for large enough smoke AOD and, over sloping coastal terrain, a smoke-induced, offshore drainage flow may exist throughout the diurnal cycle.

Building more effective sea level rise models for coastal management

Science.gov (United States)

Kidwell, D.; Buckel, C.; Collini, R.; Meckley, T.

2017-12-01

For over a decade, increased attention on coastal resilience and adaptation to sea level rise has resulted in a proliferation of predictive models and tools. This proliferation has enhanced our understanding of our vulnerability to sea level rise, but has also led to stakeholder fatigue in trying to realize the value of each advancement. These models vary in type and complexity ranging from GIS-based bathtub viewers to modeling systems that dynamically couple complex biophysical and geomorphic processes. These approaches and capabilities typically have the common purpose using scenarios of global and regional sea level change to inform adaptation and mitigation. In addition, stakeholders are often presented a plethora of options to address sea level rise issues from a variety of agencies, academics, and consulting firms. All of this can result in confusion, misapplication of a specific model/tool, and stakeholder feedback of "no more new science or tools, just help me understand which one to use". Concerns from stakeholders have led to the question; how do we move forward with sea level rise modeling? This presentation will provide a synthesis of the experiences and feedback derived from NOAA's Ecological Effects of Sea level Rise (EESLR) program to discuss the future of predictive sea level rise impact modeling. EESLR is an applied research program focused on the advancement of dynamic modeling capabilities in collaboration with local and regional stakeholders. Key concerns from stakeholder engagement include questions about model uncertainty, approaches for model validation, and a lack of cross-model comparisons. Effective communication of model/tool products, capabilities, and results is paramount to address these concerns. Looking forward, the most effective predictions of sea level rise impacts on our coast will be attained through a focus on coupled modeling systems, particularly those that connect natural processes and human response.

Arctic continental shelf morphology related to sea-ice zonation, Beaufort Sea, Alaska

Science.gov (United States)

Reimnitz, E.; Toimil, L.; Barnes, P.

1978-01-01

Landsat-1 and NOAA satellite imagery for the winter 1972-1973, and a variety of ice and sea-floor data were used to study sea-ice zonation and dynamics and their relation to bottom morphology and geology on the Beaufort Sea continental shelf of arctic Alaska. In early winter the location of the boundary between undeformed fast ice and westward-drifting pack ice of the Pacific Gyre is controlled by major coastal promontories. Pronounced linear pressure- and shear-ridges, as well as hummock fields, form along this boundary and are stabilized by grounding, generally between the 10- and 20-m isobaths. Slippage along this boundary occurs intermittently at or seaward of the grounded ridges, forming new grounded ridges in a widening zone, the stamukhi zone, which by late winter extends out to the 40-m isobath. Between intermittent events along the stamukhi zone, pack-ice drift and slippage is continuous along the shelf edge, at average rates of 3-10 km/day. Whether slippage occurs along the stamukhi zone or along the shelf edge, it is restricted to a zone several hundred meters wide, and ice seaward of the slip face moves at uniform rates without discernible drag effects. A causal relationship is seen between the spatial distribution of major ice-ridge systems and offshore shoals downdrift of major coastal promontories. The shoals appear to have migrated shoreward under the influence of ice up to 400 m in the last 25 years. The sea floor seaward of these shoals within the stamukhi zone shows high ice-gouge density, large incision depths, and a high degree of disruption of internal sedimentary structures. The concentration of large ice ridges and our sea floor data in the stamukhi zone indicate that much of the available marine energy is expended here, while the inner shelf and coast, where the relatively undeformed fast ice grows, are sheltered. There is evidence that anomalies in the overall arctic shelf profile are related to sea-ice zonation, ice dynamics, and bottom

Sea Surface Height Variability and Eddy Statistical Properties in the Red Sea

KAUST Repository

Zhan, Peng

2013-05-01

Satellite sea surface height (SSH) data over 1992-2012 are analyzed to study the spatial and temporal variability of sea level in the Red Sea. Empirical orthogonal functions (EOF) analysis suggests the remarkable seasonality of SSH in the Red Sea, and a significant correlation is found between SSH variation and seasonal wind cycle. A winding-angle based eddy identification algorithm is employed to derive the mesoscale eddy information from SSH data. Totally more than 5500 eddies are detected, belonging to 2583 eddy tracks. Statistics suggest that eddies generate over the entire Red Sea, with two regions in the central basin of high eddy frequency. 76% of the detected eddies have a radius ranging from 40km to 100km, of which both intensity and absolute vorticity decrease with eddy radius. The average eddy lifespan is about 5 weeks, and eddies with longer lifespan tend to have larger radius but less intensity. Different deformation rate exists between anticyclonic eddies (AEs) and cyclonic eddies (CEs), those eddies with higher intensity appear to be less deformed and more circular. Inspection of the 84 long-lived eddies suggests the AEs tend to move a little more northward than CEs. AE generation during summer is obviously lower than that during other seasons, while CE generation is higher during spring and summer. Other features of AEs and CEs are similar with both vorticity and intensity reaching the summer peaks in August and winter peaks in January. Inter-annual variability reveals that the eddies in the Red Sea are isolated from the global event. The eddy property tendencies are different from the south and north basin, both of which exhibit a two-year cycle. Showing a correlation coefficient of -0.91, Brunt–Väisälä frequency is negatively correlated with eddy kinetic energy (EKE), which results from AE activities in the high eddy frequency region. Climatological vertical velocity shear variation is identical with EKE except in the autumn, suggesting the

Prediction of South China sea level using seasonal ARIMA models

Science.gov (United States)

Fernandez, Flerida Regine; Po, Rodolfo; Montero, Neil; Addawe, Rizavel

2017-11-01

Accelerating sea level rise is an indicator of global warming and poses a threat to low-lying places and coastal countries. This study aims to fit a Seasonal Autoregressive Integrated Moving Average (SARIMA) model to the time series obtained from the TOPEX and Jason series of satellite radar altimetries of the South China Sea from the year 2008 to 2015. With altimetric measurements taken in a 10-day repeat cycle, monthly averages of the satellite altimetry measurements were taken to compose the data set used in the study. SARIMA models were then tried and fitted to the time series in order to find the best-fit model. Results show that the SARIMA(1,0,0)(0,1,1)12 model best fits the time series and was used to forecast the values for January 2016 to December 2016. The 12-month forecast using SARIMA(1,0,0)(0,1,1)12 shows that the sea level gradually increases from January to September 2016, and decreases until December 2016.

Boundary Layer Depth In Coastal Regions

Science.gov (United States)

Porson, A.; Schayes, G.

The results of earlier studies performed about sea breezes simulations have shown that this is a relevant feature of the Planetary Boundary Layer that still requires effort to be diagnosed properly by atmospheric models. Based on the observations made during the ESCOMPTE campaign, over the Mediterranean Sea, different CBL and SBL height estimation processes have been tested with a meso-scale model, TVM. The aim was to compare the critical points of the BL height determination computed using turbulent kinetic energy profile with some other standard evaluations. Moreover, these results have been analysed with different mixing length formulation. The sensitivity of formulation is also analysed with a simple coastal configuration.

The Helium Warm Breeze in IBEX Observations As a Result of Charge-exchange Collisions in the Outer Heliosheath

Energy Technology Data Exchange (ETDEWEB)

Bzowski, Maciej; Kubiak, Marzena A.; Czechowski, Andrzej; Grygorczuk, Jolanta, E-mail: bzowski@cbk.waw.pl [Space Research Centre PAS (CBK PAN) Bartycka 18A 00-716 Warsaw (Poland)

2017-08-10

We simulated the signal due to neutral He atoms, observed by the Interstellar Boundary Explorer ( IBEX ), assuming that charge-exchange collisions between neutral He atoms and He{sup +} ions operate everywhere between the heliopause and a distant source region in the local interstellar cloud, where the neutral and charged components are in thermal equilibrium. We simulated several test cases of the plasma flow within the outer heliosheath (OHS) and investigated the signal generation for plasma flows both in the absence and in the presence of the interstellar magnetic field (ISMF). We found that a signal in the portion of IBEX data identified as being due to the Warm Breeze (WB) does not arise when a homogeneous plasma flow in front of the heliopause is assumed, but it appears immediately when any reasonable disturbance in its flow due to the presence of the heliosphere is assumed. We obtained a good qualitative agreement between the data selected for comparison and the simulations for a model flow with the velocity vector of the unperturbed gas and the direction and intensity of magnetic field adopted from recent determinations. We conclude that direct-sampling observations of neutral He atoms at 1 au from the Sun are a sensitive tool for investigating the flow of interstellar matter in the OHS, that the WB is indeed the secondary population of interstellar helium, which was hypothesized earlier, and that the WB signal is consistent with the heliosphere distorted from axial symmetry by the ISMF.

On the Application of an Enthalpy Method to the Evolution of Fluvial Deltas Under Sea-Level Changes

Science.gov (United States)

Anderson, W.; Lorenzo-Trueba, J.; Voller, V. R.

2017-12-01

Fluvial deltas are composites of two primary sedimentary environments: a depositional fluvial region and an offshore region. The fluvial region is defined by two geomorphic moving boundaries: an alluvial-bedrock transition (ABT), which separates the sediment prism from the non-erodible bedrock basement, and the shoreline (SH), where the delta meets the ocean. The trajectories of these boundaries in time and space define the evolution of the shape of the sedimentary prism, and are often used as stratigraphic indicators, particularly in seismic studies, of changes in relative sea level and the identification of stratigraphic sequences. In order to better understand the relative role of sea-level variations, tectonics, and sediment supply on the evolution of these boundaries, we develop a forward stratigraphic model that captures the dynamic behavior of the fluvial surface and treats the SH and ABT as moving boundaries (i.e., internal boundaries whose location must be determined as part of the solution to the overall morphological evolution problem). This forward model extends a numerical technique from heat transfer (i.e., enthalpy method), previously applied to the evolution of sedimentary basins, to account for sea-level changes. The mathematics of the approach are verified by comparing predictions from the numerical model with both existing and newly developed closed form analytical solutions. Model results support previous work, which suggests that the migration of the ABT can respond very differently to the sea-level signal. This response depends on factors such as sediment supply and delta length, which can vary greatly between basins. These results can have important implications for the reconstruction of past sea-level changes from the stratigraphic record of sedimentary basins.

Embodied affectivity: On moving and being moved

Directory of Open Access Journals (Sweden)

Thomas eFuchs

2014-06-01

Full Text Available There is a growing body of research indicating that bodily sensation and behaviour strongly influences one’s emotional reaction towards certain situations or objects. On this background, a framework model of embodied affectivity is suggested: we regard emotions as resulting from the circular interaction between affective qualities or affordances in the environment and the subject’s bodily resonance, be it in the form of sensations, postures, expressive movements or movement tendencies. Motion and emotion are thus intrinsically connected: one is moved by movement (perception; impression; affection and moved to move (action; expression; e-motion. Through its resonance, the body functions as a medium of emotional perception: it colours or charges self-experience and the environment with affective valences while it remains itself in the background of one’s own awareness. This model is then applied to emotional social understanding or interaffectivity which is regarded as an intertwinement of two cycles of embodied affectivity, thus continuously modifying each partner’s affective affordances and bodily resonance. We conclude with considerations of how embodied affectivity is altered in psychopathology and can be addressed in psychotherapy of the embodied self.

Method and apparatus for a combination moving bed thermal treatment reactor and moving bed filter

Energy Technology Data Exchange (ETDEWEB)

Badger, Phillip C.; Dunn, Jr., Kenneth J.

2015-09-01

A moving bed gasification/thermal treatment reactor includes a geometry in which moving bed reactor particles serve as both a moving bed filter and a heat carrier to provide thermal energy for thermal treatment reactions, such that the moving bed filter and the heat carrier are one and the same to remove solid particulates or droplets generated by thermal treatment processes or injected into the moving bed filter from other sources.

Preliminary study of the offshore wind and temperature profiles at the North of the Yucatan Peninsula

International Nuclear Information System (INIS)

Soler-Bientz, Rolando; Watson, Simon; Infield, David; Ricalde-Cab, Lifter

2011-01-01

Highlights: → This is the first study that reports the properties of the vertical wind resources for the offshore conditions of the North coast of the Yucatan Peninsula. → A significant and detailed analysis of the thermal patterns has revealed a complex structure of the atmospheric boundary layer close to the shore. → The structure of the diurnal wind patterns was assessed to produce an important reference for the wind resource availability in the study region. → It was identified that the sea breeze blows in directions almost parallel to the shoreline of the North of the Yucatan Peninsula during the majority of the 24 h cycle. → The analysis of the offshore data revealed a persistent non-uniform surface boundary layer developed as result of the advection of a warn air over a cold sea. - Abstract: The stability conditions in the atmospheric boundary layer, the intensity of the wind speeds and consequently the energy potential available in offshore conditions are highly influenced by the distance from the coastline and the differences between the air and sea temperatures. This paper presents a preliminary research undertook to study the offshore wind and temperature vertical profiles at the North-West of the Yucatan Peninsula coast. Ten minute averages were recorded over approximately 2 years from sensors installed at two different heights on a communication tower located at 6.65 km from the coastline. The results have shown that the offshore wind is thermally driven by differential heating of land and sea producing breeze patterns which veer to blow parallel to the coast under the action of the Coriolis force. To investigate further, a dataset of hourly sea surface temperatures derived from GEOS Satellite thermal maps was combined with the onsite measured data to study its effect on the vertical temperature profile. The results suggested largely unstable conditions and the potentially development of a shallow Stable Internal Boundary Layer which occurs

Climate And Sea Level: It's In Our Hands Now

Science.gov (United States)

Turrin, M.; Bell, R. E.; Ryan, W. B. F.

2014-12-01

Changes in sea level are measurable on both a local and a global scale providing an accessible way to connect climate to education, yet engaging teachers and students with the complex science that is behind the change in sea level can be a challenge. Deciding how much should be included and just how it should be introduced in any single classroom subject area can be an obstacle for a teacher. The Sea Level Rise Polar Explorer App developed through the PoLAR CCEP grant offers a guided tour through the many layers of science that impact sea level rise. This map-based data-rich app is framed around a series of questions that move the user through map layers with just the level of complexity they chose to explore. For a quick look teachers and students can review a 3 or 4 sentence introduction on how the given map links to sea level and then launch straight into the interactive touchable map. For a little more in depth look they can listen to (or read) a one-minute recorded background on the data displayed in the map prior to launching in. For those who want more in depth understanding they can click to a one page background piece on the topic with links to further visualizations, videos and data. Regardless of the level of complexity selected each map is composed of clickable data allowing the user to fully explore the science. The different options for diving in allow teachers to differentiate the learning for either the subject being taught or the user level of the student group. The map layers also include a range of complexities. Basic questions like "What is sea level?" talk about shorelines, past sea levels and elevations beneath the sea. Questions like "Why does sea level change?" includes slightly more complex issues like the role of ocean temperature, and how that differs from ocean heat content. And what is the role of the warming atmosphere in sea level change? Questions about "What about sea level in the past?" can bring challenges for students who have

Analysis of the Dose Distribution of Moving Organ using a Moving Phantom System

International Nuclear Information System (INIS)

Kim, Yon Lae; Park, Byung Moon; Bae, Yong Ki; Kang, Min Young; Bang, Dong Wan; Lee, Gui Won

2006-01-01

Few researches have been performed on the dose distribution of the moving organ for radiotherapy so far. In order to simulate the organ motion caused by respiratory function, multipurpose phantom and moving device was used and dosimetric measurements for dose distribution of the moving organs were conducted in this study. The purpose of our study was to evaluate how dose distributions are changed due to respiratory motion. A multipurpose phantom and a moving device were developed for the measurement of the dose distribution of the moving organ due to respiratory function. Acryl chosen design of the phantom was considered the most obvious choice for phantom material. For construction of the phantom, we used acryl and cork with density of 1.14 g/cm 3 , 0.32 g/cm 3 respectively. Acryl and cork slab in the phantom were used to simulate the normal organ and lung respectively. The moving phantom system was composed of moving device, moving control system, and acryl and cork phantom. Gafchromic film and EDR2 film were used to measure dose distributions. The moving device system may be driven by two directional step motors and able to perform 2 dimensional movements (x, z axis), but only 1 dimensional movement(z axis) was used for this study. Larger penumbra was shown in the cork phantom than in the acryl phantom. The dose profile and isodose curve of Gafchromic EBT film were not uniform since the film has small optical density responding to the dose. As the organ motion was increased, the blurrings in penumbra, flatness, and symmetry were increased. Most of measurements of dose distributions, Gafchromic EBT film has poor flatness and symmetry than EDR2 film, but both penumbra distributions were more or less comparable. The Gafchromic EBT film is more useful as it does not need development and more radiation dose could be exposed than EDR2 film without losing film characteristics. But as response of the optical density of Gafchromic EBT film to dose is low, beam profiles

Frentes de brisa en el Levante español

Directory of Open Access Journals (Sweden)

Olcina Cantos, Jorge

2004-03-01

Full Text Available Breeze regimes are main winds circulation during warm period of the year (April-September in the East of the Iberian Peninsula. This analysis offers a typology of sea breeze fronts in Spanish Mediterranean area and considers its close relationship with thermal features in Mediterranean sea all year along. The paper studies meteorological causes connected with this atmospheric phenomenon and emphasizes about pluviometric importance in contact with origin of instable sea breeze fronts in mountain areas near to Mediterranean coast.

[es] Los regímenes de brisas constituyen la principal circulación de vientos durante el semestre cálido del año (abril-septiembre en el Levante español. El presente estudio establece una tipología de frentes de brisa que se desarrollan en este espacio geográfico ibérico y su estrecha relación con los rasgos térmicos del mar Mediterráneo a lo largo del año. Se analizan las causas atmosféricas asociadas a este fenómeno meteorológico y se enfatiza en la importancia pluviométrica ligada al estallido de frentes de brisa inestables en las áreas montañosas próximas al litoral mediterráneo. [fr] Les circulations de brises constitue le mécanisme principal de vents pendant le semestre chaud de l'année (avril - septembre sur le Levant Espagnol. L'étude présente établit une typologie de fronts de brise qui développent dans cet espace géographique et son la relation étroite avec les caractéristiques thermales de la mer Méditerranée pendant l'année. Là sont analysé les raisons atmosphériques associées à ce phénomène météorologique et il est souligné dans l'importance pluviométrica lié à la formation de fronts instables de brise dans les secteurs montagneux près le littoral méditerranée espagnol.

Distinctive Microbial Community Structure in Highly Stratified Deep-Sea Brine Water Columns

KAUST Repository

Bougouffa, Salim; Yang, J. K.; Lee, O. O.; Wang, Y.; Batang, Zenon B.; Al-Suwailem, Abdulaziz M.; Qian, P. Y.

2013-01-01

Atlantis II and Discovery are two hydrothermal and hypersaline deep-sea pools in the Red Sea rift that are characterized by strong thermohalo-stratification and temperatures steadily peaking near the bottom. We conducted comprehensive vertical profiling of the microbial populations in both pools and highlighted the influential environmental factors. Pyrosequencing of the 16S rRNA genes revealed shifts in community structures vis-à-vis depth. High diversity and low abundance were features of the deepest convective layers despite the low cell density. Surprisingly, the brine interfaces had significantly higher cell counts than the overlying deep-sea water, yet they were lowest in diversity. Vertical stratification of the bacterial populations was apparent as we moved from the Alphaproteobacteria-dominated deep sea to the Planctomycetaceae- or Deferribacteres-dominated interfaces to the Gammaproteobacteria-dominated brine layers. Archaeal marine group I was dominant in the deep-sea water and interfaces, while several euryarchaeotic groups increased in the brine. Across sites, microbial phylotypes and abundances varied substantially in the brine interface of Discovery compared with Atlantis II, despite the near-identical populations in the overlying deep-sea waters. The lowest convective layers harbored interestingly similar microbial communities, even though temperature and heavy metal concentrations were very different. Multivariate analysis indicated that temperature and salinity were the major influences shaping the communities. The harsh conditions and the low-abundance phylotypes could explain the observed correlation in the brine pools.

Distinctive Microbial Community Structure in Highly Stratified Deep-Sea Brine Water Columns

KAUST Repository

Bougouffa, Salim

2013-03-29

Atlantis II and Discovery are two hydrothermal and hypersaline deep-sea pools in the Red Sea rift that are characterized by strong thermohalo-stratification and temperatures steadily peaking near the bottom. We conducted comprehensive vertical profiling of the microbial populations in both pools and highlighted the influential environmental factors. Pyrosequencing of the 16S rRNA genes revealed shifts in community structures vis-à-vis depth. High diversity and low abundance were features of the deepest convective layers despite the low cell density. Surprisingly, the brine interfaces had significantly higher cell counts than the overlying deep-sea water, yet they were lowest in diversity. Vertical stratification of the bacterial populations was apparent as we moved from the Alphaproteobacteria-dominated deep sea to the Planctomycetaceae- or Deferribacteres-dominated interfaces to the Gammaproteobacteria-dominated brine layers. Archaeal marine group I was dominant in the deep-sea water and interfaces, while several euryarchaeotic groups increased in the brine. Across sites, microbial phylotypes and abundances varied substantially in the brine interface of Discovery compared with Atlantis II, despite the near-identical populations in the overlying deep-sea waters. The lowest convective layers harbored interestingly similar microbial communities, even though temperature and heavy metal concentrations were very different. Multivariate analysis indicated that temperature and salinity were the major influences shaping the communities. The harsh conditions and the low-abundance phylotypes could explain the observed correlation in the brine pools.

High contributions of sea ice derived carbon in polar bear (Ursus maritimus) tissue.

Science.gov (United States)

Brown, Thomas A; Galicia, Melissa P; Thiemann, Gregory W; Belt, Simon T; Yurkowski, David J; Dyck, Markus G

2018-01-01

Polar bears (Ursus maritimus) rely upon Arctic sea ice as a physical habitat. Consequently, conservation assessments of polar bears identify the ongoing reduction in sea ice to represent a significant threat to their survival. However, the additional role of sea ice as a potential, indirect, source of energy to bears has been overlooked. Here we used the highly branched isoprenoid lipid biomarker-based index (H-Print) approach in combination with quantitative fatty acid signature analysis to show that sympagic (sea ice-associated), rather than pelagic, carbon contributions dominated the marine component of polar bear diet (72-100%; 99% CI, n = 55), irrespective of differences in diet composition. The lowest mean estimates of sympagic carbon were found in Baffin Bay bears, which were also exposed to the most rapidly increasing open water season. Therefore, our data illustrate that for future Arctic ecosystems that are likely to be characterised by reduced sea ice cover, polar bears will not only be impacted by a change in their physical habitat, but also potentially in the supply of energy to the ecosystems upon which they depend. This data represents the first quantifiable baseline that is critical for the assessment of likely ongoing changes in energy supply to Arctic predators as we move into an increasingly uncertain future for polar ecosystems.

Sea surface temperatures and salinities from platforms in the Barents Sea, Sea of Japan, North Atlantic Ocean, Philippine Sea, Red Sea, and the South China Sea (Nan Hai) from 1896-1950 (NODC Accession 0000506)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Surface temperatures and salinities were collected in the Barents Sea, Sea of Japan, North Atlantic Ocean, Philippine Sea, Red Sea, and South China Sea (Nan Hai)...

Bolsa Bay, California, Proposed Ocean Entrance System Study. Report 2. Comprehensive Shoreline Response Computer Simulation, Bolsa Bay, California

Science.gov (United States)

1990-04-01

Southern California Bight is affected by a land-sea breeze pattern. A variation in flow is caused by the heating of the land surface during the day, and...1980). 27. The success of the inlet channel at Agua Hedionda indicates that a stable non-navigable entrance at Bolsa Chica could be feasible provided a...dual jetty system similar to Agua Hedionda is incorporated into the design. However, structures that penetrate into the active surf zone are expected

Detection of moving objects from a moving platform in urban scenes

NARCIS (Netherlands)

Haar, F.B. ter; Hollander, R.J.M. den; Dijk, J.

2010-01-01

Moving object detection in urban scenes is important for the guidance of autonomous vehicles, robot navigation, and monitoring. In this paper moving objects are automatically detected using three sequential frames and tracked over a longer period. To this extend we modify the plane+parallax,

Identification of moving vehicle forces on bridge structures via moving average Tikhonov regularization

Science.gov (United States)

Pan, Chu-Dong; Yu, Ling; Liu, Huan-Lin

2017-08-01

Traffic-induced moving force identification (MFI) is a typical inverse problem in the field of bridge structural health monitoring. Lots of regularization-based methods have been proposed for MFI. However, the MFI accuracy obtained from the existing methods is low when the moving forces enter into and exit a bridge deck due to low sensitivity of structural responses to the forces at these zones. To overcome this shortcoming, a novel moving average Tikhonov regularization method is proposed for MFI by combining with the moving average concepts. Firstly, the bridge-vehicle interaction moving force is assumed as a discrete finite signal with stable average value (DFS-SAV). Secondly, the reasonable signal feature of DFS-SAV is quantified and introduced for improving the penalty function (∣∣x∣∣2 2) defined in the classical Tikhonov regularization. Then, a feasible two-step strategy is proposed for selecting regularization parameter and balance coefficient defined in the improved penalty function. Finally, both numerical simulations on a simply-supported beam and laboratory experiments on a hollow tube beam are performed for assessing the accuracy and the feasibility of the proposed method. The illustrated results show that the moving forces can be accurately identified with a strong robustness. Some related issues, such as selection of moving window length, effect of different penalty functions, and effect of different car speeds, are discussed as well.

Performance Evaluation of Moving Bed Bio Film Reactor in Saline Wastewater Treatment

Directory of Open Access Journals (Sweden)

M Ahmadi

2013-06-01

Full Text Available Background and purpose:Moving Bed Biofilm Reactor is an aerobic attached growth with better biofilm thickness control, lack of plugging and lower head loss. Consequently, this system is greatly used by different wastewater treatment plants. High TDS wastewater produced petrochemical, leather tanning, sea food processing, cannery, pickling and dairy industries. The aim of this study was to evaluate the performance of MBBR in saline wastewater treatment. Materials and methods: In this study, 50 percent of a cylindrical reactor with 9.5 liter occupied media with 650 m2.m-3. In the first step, hydraulic regime was evaluated and startup reactor was done by sanitary sludge. Bio film was generated with glucose as the sole carbon source in synthetic wastewater. MBBR performance evaluation was performed in 6:30 and 8:45 with saline wastewater after bio film produced on media. Results: After 83 days of passing MBBR operation with saline wastewater containing 3000-12000 mg.L-1 TDS, organic loading rate of 2.2-3.5 kg/m3.d COD removal efficiency reached 80-92%. Conclusion: Moving bed biofilm reactor is effective in organic load elimination from saline wastewater.

Error analysis of motion correction method for laser scanning of moving objects

Science.gov (United States)

Goel, S.; Lohani, B.

2014-05-01

The limitation of conventional laser scanning methods is that the objects being scanned should be static. The need of scanning moving objects has resulted in the development of new methods capable of generating correct 3D geometry of moving objects. Limited literature is available showing development of very few methods capable of catering to the problem of object motion during scanning. All the existing methods utilize their own models or sensors. Any studies on error modelling or analysis of any of the motion correction methods are found to be lacking in literature. In this paper, we develop the error budget and present the analysis of one such `motion correction' method. This method assumes availability of position and orientation information of the moving object which in general can be obtained by installing a POS system on board or by use of some tracking devices. It then uses this information along with laser scanner data to apply correction to laser data, thus resulting in correct geometry despite the object being mobile during scanning. The major application of this method lie in the shipping industry to scan ships either moving or parked in the sea and to scan other objects like hot air balloons or aerostats. It is to be noted that the other methods of "motion correction" explained in literature can not be applied to scan the objects mentioned here making the chosen method quite unique. This paper presents some interesting insights in to the functioning of "motion correction" method as well as a detailed account of the behavior and variation of the error due to different sensor components alone and in combination with each other. The analysis can be used to obtain insights in to optimal utilization of available components for achieving the best results.

Electrical guidance efficiency of downstream-migrating juvenile Sea Lamprey decreases with increasing water velocity

Science.gov (United States)

Miehls, Scott M.; Johnson, Nicholas; Haro, Alexander

2017-01-01

We tested the efficacy of a vertically oriented field of pulsed direct current (VEPDC) created by an array of vertical electrodes for guiding downstream-moving juvenile Sea Lampreys Petromyzon marinus to a bypass channel in an artificial flume at water velocities of 10–50 cm/s. Sea Lampreys were more likely to be captured in the bypass channel than in other sections of the flume regardless of electric field status (on or off) or water velocity. Additionally, Sea Lampreys were more likely to be captured in the bypass channel when the VEPDC was active; however, an interaction between the effects of VEPDC and water velocity was observed, as the likelihood of capture decreased with increases in water velocity. The distribution of Sea Lampreys shifted from right to left across the width of the flume toward the bypass channel when the VEPDC was active at water velocities less than 25 cm/s. The VEPDC appeared to have no effect on Sea Lamprey distribution in the flume at water velocities greater than 25 cm/s. We also conducted separate tests to determine the threshold at which Sea Lampreys would become paralyzed. Individuals were paralyzed at a mean power density of 37.0 µW/cm3. Future research should investigate the ability of juvenile Sea Lampreys to detect electric fields and their specific behavioral responses to electric field characteristics so as to optimize the use of this technology as a nonphysical guidance tool across variable water velocities.

MOVES regional level sensitivity analysis

Science.gov (United States)

2012-01-01

The MOVES Regional Level Sensitivity Analysis was conducted to increase understanding of the operations of the MOVES Model in regional emissions analysis and to highlight the following: : the relative sensitivity of selected MOVES Model input paramet...

The distribution and diversity of sea cucumbers in the coral reefs of the South China Sea, Sulu Sea and Sulawesi Sea

Science.gov (United States)

Woo, Sau Pinn; Yasin, Zulfigar; Ismail, Siti Hasmah; Tan, Shau Hwai

2013-11-01

A study on the distribution and diversity of sea cucumbers in the coral reefs of the South China Sea, Sulu Sea and Sulawesi Sea was carried out in July 2009. The survey was done using wandering transect underwater with SCUBA. Twelve species of sea cucumber were found from four different families and nine genera. The most dominant family was Holothuriidae (five species), followed by Stichopodidae (three species), Synaptidae (three species) and Cucumariidae with only one species. The most dominant species found around the island was Pearsonothuria graffei, which can be found abundantly on substrate of dead corals in a wide range of depth (6-15 m). The Sulawesi Sea showed a higher diversity of sea cucumber with seven different species compared to the South China Sea with only six different species and Sulu Sea with only two species. Ordination by multidimensional scaling of Bray-Curtis similarities clustered the sampling locations to three main clusters with two outgroups. Previous studies done indicated a higher diversity of sea cucumber as compared to this study. This can be indication that the population and diversity of sea cucumbers in the reef is under threat.

Assessing the impact of sea-level rise on a vulnerable coastal community in Accra, Ghana

Directory of Open Access Journals (Sweden)

Kwasi Appeaning Addo

2013-08-01

Full Text Available Climate change and its associated sea-level rise are expected to significantly affect vulnerable coastal communities. Although the extent of the impact will be localised, its assessment will adopt a monitoring approach that applies globally. The topography of the beach, the type of geological material and the level of human intervention will determine the extent of the area to be flooded and the rate at which the shoreline will move inland. Gleefe, a coastal community in Ghana, has experienced frequent flooding in recent times due to the increasing occurrence of storm surge and sea-level rise. This study used available geospatial data and field measurements to determine how the beach topography has contributed to the incidence of flooding at Gleefe. The topography is generally low-lying. Sections of the beach have elevations of around 1 m, which allows seawater to move inland during very high tide. Accelerated sea-level rise as predicted by the Intergovernmental Panel on Climate Change (IPCC will destroy homes of the inhabitants and inundate the Densu wetlands behind the beach. Destruction of infrastructure will render the inhabitants homeless, whilst flooding of the wetlands will destroy the habitats of migratory birds and some endangered wildlife species such as marine turtle. Effective adaptation measures should be adopted to protect this very important coastal environment, the ecology of the wetlands and the livelihoods of the community dwellers.

Diurnal Sea Breeze Effects on Nearshore Temperature Variability in Southern Monterey Bay

Science.gov (United States)

2017-12-01

from multi-year, single-location measurements of the velocity profiles (Fewings et al. 2008; Lentz et al. 2008; Hendrickson and MacMahan 2009) to...shorter O(0-2 months) experiments with multi-location moorings (Hally- Rosendahl et al. 2015; Reniers et al. 2009). Direct approaches for accounting for...zone (~5m). Two cross-shore arrays were deployed to account for the spatial heterogeneity of cross- shore flows associated with rip currents on the

Trapping fresh sea breeze in desert? Health status of Camanchaca, Atacama's fog.

Science.gov (United States)

Bonnail, Estefanía; Cunha Lima, Ricardo; Martínez Turrieta, Gladys

2018-05-24

Water fog composition was investigated at a fog harvesting installation in the coast of Atacama (North Chile). Chañaral is historically affected by mining contamination discharges. Hydro-chemical characterization of fog water from top of the mountain (where capture installation is located) and at the bottom of the mountain (after vertical transportation where an aquaponic system is located) revealed many compositional differences that compromise the use of water. High acidity and high concentrations in Cu and As in water collected on top of the mountain were found; meanwhile, acidity and Cu decreased, and As levels overpassed the drinking water standards after the vertical transportation. Collected data was assessed according to national and international regulatory standards, neutralization factors (NF), sodium adsorption ratio (SAR), and ion ratios to determine origin of contamination and suitability of destined for human consumption, irrigation, or aquaculture purposes.

The Nature of The Propagation of Sea Breeze Fronts in Central California

Science.gov (United States)

1990-09-01

propagation vector % ith stations in the southern portion of Monterey Bay shows that the front is curved on the mesoscale. 20 Distribution Availabilit of...solar radiation warms the land more than the adjacent water . The resulting temperature contrast produces a slight variation in pressure. The isobaric...surfaces bend upward over the land, producing an upper-level high. The upper-level air flows seaward increasing the surface pressure over the water . The

Moving Field Guides

Science.gov (United States)

Cassie Meador; Mark Twery; Meagan. Leatherbury

2011-01-01

The Moving Field Guides (MFG) project is a creative take on site interpretation. Moving Field Guides provide an example of how scientific and artistic endeavors work in parallel. Both begin with keen observations that produce information that must be analyzed, understood, and interpreted. That interpretation then needs to be communicated to others to complete the...

Model study of meteorology and photochemical air pollution over un urban area in south-eastern France (ESCOMPTE campaign).

Science.gov (United States)

Taghavi, M.; Cautenet, S.

2003-04-01

The ESCOMPTE Campaign has been conducted over Southern France (Provence region including the Marseille, Aix and Toulon cities and the Fos-Berre industrial center) in June and July of 2001. In order to study the redistribution of the pollutants emitted by anthropic and biogenic emissions and their impact on the atmospheric chemistry, we used meso-scale modeling (RAMS model, paralleled version 4.3, coupled on line with chemical modules : MOCA2.2 (Poulet et al, 2002) including 29 gaseous species). The hourly high resolution emissions were obtained from ESCOMPTE database (Ponche et al, 2002). The model was coupled with the dry deposition scheme (Walmsley and Weseley,1996). In this particular case of complex circulation (sea breeze associated with topography), the processes involving peaks of pollution were strongly non linear, and the meso scale modeling coupled on line with chemistry module was an essential step for a realistic redistribution of chemical species. Two nested grids satisfactorily describe the synoptic dynamics and the sea breeze circulations. The ECMWF meteorological fields provide the initial and boundary conditions. Different events characterized by various meteorological situations were simulated. Meteorological fields retrieved by modeling, also Modeled ozone, NOx, CO and SO2 concentrations, were compared with balloons, lidars, aircrafts and surface stations measurements. The chemistry regimes were explained according to the distribution of plumes. The stratified layers were examined.

The Biological Deep Sea Hydrothermal Vent as a Model to Study Carbon Dioxide Capturing Enzymes

Directory of Open Access Journals (Sweden)

Premila D. Thongbam

2011-04-01

Full Text Available Deep sea hydrothermal vents are located along the mid-ocean ridge system, near volcanically active areas, where tectonic plates are moving away from each other. Sea water penetrates the fissures of the volcanic bed and is heated by magma. This heated sea water rises to the surface dissolving large amounts of minerals which provide a source of energy and nutrients to chemoautotrophic organisms. Although this environment is characterized by extreme conditions (high temperature, high pressure, chemical toxicity, acidic pH and absence of photosynthesis a diversity of microorganisms and many animal species are specially adapted to this hostile environment. These organisms have developed a very efficient metabolism for the assimilation of inorganic CO2 from the external environment. In order to develop technology for the capture of carbon dioxide to reduce greenhouse gases in the atmosphere, enzymes involved in CO2 fixation and assimilation might be very useful. This review describes some current research concerning CO2 fixation and assimilation in the deep sea environment and possible biotechnological application of enzymes for carbon dioxide capture.

Physical Climatology of Indonesian Maritime Continent: An Overview of Observational Studies

Science.gov (United States)

Yamanaka, M. D.

2014-12-01

The Indonesian maritime continent (IMC) is a miniature of our land-sea coexisting planet Earth. Firstly, without interior activity, the Earth becomes an even-surfaced "aqua-planet" with both atmosphere and ocean flowing almost zonally, and solar differential heating generates (global thermal tides and) Hadley's meridional circulations with ITCZ along the equator as observed actually over open (Indian and Pacific) oceans in the both sides of IMC. ITCZ involves intraseasonal variations or super cloud clusters moving eastward. Secondly, the lands and seas over the actual Earth have been keeping the area ratio of 3:7 (similar to that of islands and inland/surrounding seas in IMC), but their displacements have produced IMC near the equator, which turns equatorial Pacific easterly current northward (Kuroshio) and reflects equatorial oceanic waves inducing coupled ocean-atmosphere interannual variations such as ENSO and IOD, or displacements of Walker's zonal circulations. Thirdly, because IMC consists of many large/small islands with very long coastlines, many narrow straits become a dam for the global (Pacific to Indian) ocean circulation, and the land-sea heat capacity contrasts along the coastlines generate the world's largest rainfall with diurnal cycles (sea-land breeze circulations). The diurnal cycles are dominant in the rainy season (austral summer in Jawa and Bali), because rainfall-induced sprinkler-like land cooling reverses the trans-coastal temperature gradient before sunrise, and subsequent clear sky on land until around noon provides solar heating dependent on season. These processes lead to rapid land/hydrosphere-atmosphere water exchange, local air pollutant washout, and transequatorial boreal winter monsoon (cold surge). In El Niño years the cooler sea-surface temperature suppresses the morning coastal-sea rainfall, and induces often serious smog over IMC. Lastly, high-resolution observations/models covering both over islands and seas are necessary. A

The ozone pollution and the climatology in a Mediterranean space: the Alpes-Maritimes

International Nuclear Information System (INIS)

Martin, N.

2008-12-01

surroundings. The appeal to the meteorological model RAMS allows then to understand better the spatial and temporal ozone variability led by the local climatic conditions. The meteorological variables the most correlated to the ozone concentrations are the wind speed, the turbulent kinetic energy, the planetary boundary layer height and the relative humidity. Everything indicates that less the volume of air in which primary pollutants are emitted is important, and less the air admixture intensity is strong, then more the ozone concentrations are raised. It would also seem that this local weather conditions have more influence on the ozone pollution levels than the macro-scale weather configurations. Although being necessary, presence of the anticyclone on the Western Europe is not sufficient to explain local ozone behaviour in the Alpes-Maritimes. At the same time as these various approaches, the spatial previous history of the photochemical pollution affecting this mountainous littoral space are looked for. The advection of important ozone quantities by the sea breeze during day, indicates that this pollutant accumulates above the sea; except the phenomenon of round trip of the air mass guided by the alternation between the sea breeze and the land breeze, the origin of the strong ozone concentrations above the sea is not clearly included. It would seem that a plan of recirculation of the air masses in three dimensions allows the creation of a pile of layers stratified on the sea. (author)

Defying Dissolution: Discovery of Deep-Sea Scleractinian Coral Reefs in the North Pacific.

Science.gov (United States)

Baco, Amy R; Morgan, Nicole; Roark, E Brendan; Silva, Mauricio; Shamberger, Kathryn E F; Miller, Kelci

2017-07-14

Deep-sea scleractinian coral reefs are protected ecologically and biologically significant areas that support global fisheries. The absence of observations of deep-sea scleractinian reefs in the Central and Northeast Pacific, combined with the shallow aragonite saturation horizon (ASH) and high carbonate dissolution rates there, fueled the hypothesis that reef formation in the North Pacific was improbable. Despite this, we report the discovery of live scleractinian reefs on six seamounts of the Northwestern Hawaiian Islands and Emperor Seamount Chain at depths of 535-732 m and aragonite saturation state (Ω arag ) values of 0.71-1.33. Although the ASH becomes deeper moving northwest along the chains, the depth distribution of the reefs becomes shallower, suggesting the ASH is having little influence on their distribution. Higher chlorophyll moving to the northwest may partially explain the geographic distribution of the reefs. Principle Components Analysis suggests that currents are also an important factor in their distribution, but neither chlorophyll nor the available current data can explain the unexpected depth distribution. Further environmental data is needed to elucidate the reason for the distribution of these reefs. The discovery of reef-forming scleractinians in this region is of concern because a number of the sites occur on seamounts with active trawl fisheries.

Radiotracers in the Black Sea: A Tool for Marine Environmental Assessments

International Nuclear Information System (INIS)

Gulin, S.B.; Egorov, V.N.; Polikarpov, G.G.; Stokozov, N.A.; Mirzoeva, N.Yu.; Tereshenko, N.N.; Gulina, L.V.; Proskurnin, V.Yu.; Osvath, I.

2011-01-01

Owing to its geographical location, the Black Sea has been one of the marine basins most contaminated with artificial radioactivity. During the pre-Chernobyl period, the main source of radioactive contamination of the Black Sea was the global fallout from the atmospheric nuclear weapon tests, which peaked in 1962 before the 1963 Test Ban Treaty was signed between the main nuclear states. As maximum global fallout was observed within the 40-50 o N latitude band that runs exactly across the Black Sea, this semi enclosed water body received high levels of the fallout radionuclides derived from the atmospheric weapons testing. Being a closest marine body to the Chernobyl site, the Black Sea and its broad drainage areas have received substantial amounts of the long-lived artificial radionuclides, particularly 90 Sr, 137 Cs, and plutonium isotopes, released into the atmosphere from the damaged nuclear reactor and delivered with the air masses moving south- and westward from the accident area. Besides direct atmospheric deposition, the Black Sea received (and continues to receive) additional radioactive input by river runoff, particularly to its northwestern area from the Danube and Dnieper Rivers. Resulting from contribution of the above-mentioned sources of radioactive contamination of the Black Sea, the 90 Sr concentration in its water ranks second after the Irish Sea, and third after the Baltic Sea with respect to 137 Cs concentration in seawater. Overview of results. Extensive radioecological studies performed during the last decades have showed that post-Chernobyl evolution and levels of man-made radioactivity in the Black Sea were governed, except radioactive decay, by the large-scale oceanographic, biogeochemical and ecological processes, which control the self-cleaning of the Black Sea environments against the radioactive contamination: first of all the vertical water mixing, which dilutes the surface radionuclide concentrations, the loss through the Bosporus

After continents divide: Comparative phylogeography of reef fishes from the Red Sea and Indian Ocean

KAUST Repository

Dibattista, Joseph D.; Berumen, Michael L.; Gaither, Michelle R.; Rocha, Luiz A.; Eble, Jeff A.; Choat, John Howard; Craig, Matthew T.; Skillings, Derek J.; Bowen, Brian W.

2013-01-01

Aim: The Red Sea is a biodiversity hotspot characterized by a unique marine fauna and high endemism. This sea began forming c. 24 million years ago with the separation of the African and Arabian plates, and has been characterized by periods of desiccation, hypersalinity and intermittent connection to the Indian Ocean. We aim to evaluate the impact of these events on the genetic architecture of the Red Sea reef fish fauna. Location: Red Sea and Western Indian Ocean. Methods: We surveyed seven reef fish species from the Red Sea and adjacent Indian Ocean using mitochondrial DNA cytochrome c oxidase subunit I and cytochrome b sequences. To assess genetic variation and evolutionary connectivity within and between these regions, we estimated haplotype diversity (h) and nucleotide diversity (π), reconstructed phylogenetic relationships among haplotypes, and estimated gene flow and time of population separation using Bayesian coalescent-based methodology. Results: Our analyses revealed a range of scenarios from shallow population structure to diagnostic differences that indicate evolutionary partitions and possible cryptic species. Conventional molecular clocks and coalescence analyses indicated time-frames for divergence between these bodies of water ranging from 830,000 years to contemporary exchange or recent range expansion. Colonization routes were bidirectional, with some species moving from the Indian Ocean to the Red Sea compared with expansion out of the Red Sea for other species. Main conclusions: We conclude that: (1) at least some Red Sea reef fauna survived multiple salinity crises; (2) endemism is higher in the Red Sea than previously reported; and (3) the Red Sea is an evolutionary incubator, occasionally contributing species to the adjacent Indian Ocean. The latter two conclusions - elevated endemism and species export - indicate a need for enhanced conservation priorities for the Red Sea. © 2013 Blackwell Publishing Ltd.

After continents divide: Comparative phylogeography of reef fishes from the Red Sea and Indian Ocean

KAUST Repository

Dibattista, Joseph D.

2013-01-07

Aim: The Red Sea is a biodiversity hotspot characterized by a unique marine fauna and high endemism. This sea began forming c. 24 million years ago with the separation of the African and Arabian plates, and has been characterized by periods of desiccation, hypersalinity and intermittent connection to the Indian Ocean. We aim to evaluate the impact of these events on the genetic architecture of the Red Sea reef fish fauna. Location: Red Sea and Western Indian Ocean. Methods: We surveyed seven reef fish species from the Red Sea and adjacent Indian Ocean using mitochondrial DNA cytochrome c oxidase subunit I and cytochrome b sequences. To assess genetic variation and evolutionary connectivity within and between these regions, we estimated haplotype diversity (h) and nucleotide diversity (π), reconstructed phylogenetic relationships among haplotypes, and estimated gene flow and time of population separation using Bayesian coalescent-based methodology. Results: Our analyses revealed a range of scenarios from shallow population structure to diagnostic differences that indicate evolutionary partitions and possible cryptic species. Conventional molecular clocks and coalescence analyses indicated time-frames for divergence between these bodies of water ranging from 830,000 years to contemporary exchange or recent range expansion. Colonization routes were bidirectional, with some species moving from the Indian Ocean to the Red Sea compared with expansion out of the Red Sea for other species. Main conclusions: We conclude that: (1) at least some Red Sea reef fauna survived multiple salinity crises; (2) endemism is higher in the Red Sea than previously reported; and (3) the Red Sea is an evolutionary incubator, occasionally contributing species to the adjacent Indian Ocean. The latter two conclusions - elevated endemism and species export - indicate a need for enhanced conservation priorities for the Red Sea. © 2013 Blackwell Publishing Ltd.

Photovoltaic at Hollywood and Desert Breeze Recreational Centers

Energy Technology Data Exchange (ETDEWEB)

Ammerman, Shane [Clark County Comprehensive Planning Department, NV (United States)

2015-09-24

Executive Summary Renewable Energy Initiatives for Clark County Parks and Recreation Solar Project DOE grant # DE-EE0003180 In accordance with the goals of the Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy for promoting solar energy as clean, carbon-free and cost-effective, the County believed that a recreational center was an ideal place to promote solar energy technologies to the public. This project included the construction of solar electricity generation facilities (40kW) at two Clark County facility sites, Desert Breeze Recreational Center and Hollywood Recreational Center, with educational kiosks and Green Boxes for classroom instruction. The major objectives and goals of this Solar Project include demonstration of state of the art technologies for the generation of electricity from solar technology and the creation of an informative and educational tool in regards to the benefits and process of generating alternative energy. Clark County partnered with Anne Johnson (design architect/consultant), Affiliated Engineers Inc. (AEI), Desert Research Institute (DRI), and Morse Electric. The latest photovoltaic technologies were used in the project to help create the greatest expected energy savings for60443 each recreational center. This coupled with the data created from the monitoring system will help Clark County and NREL further understand the real time outputs from the system. The educational portion created with AEI and DRI incorporates material for all ages with a focus on K - 12. The AEI component is an animated story telling the fundamentals of how sunlight is turned into electricity and DRI‘s creation of Solar Green Boxes brings environmental education into the classroom. In addition to the educational component for the public, the energy that is created through the photovoltaic system also translates into saved money and health benefits for the general public. This project has helped Clark County to further add to its own

High contributions of sea ice derived carbon in polar bear (Ursus maritimus tissue.

Directory of Open Access Journals (Sweden)

Thomas A Brown

Full Text Available Polar bears (Ursus maritimus rely upon Arctic sea ice as a physical habitat. Consequently, conservation assessments of polar bears identify the ongoing reduction in sea ice to represent a significant threat to their survival. However, the additional role of sea ice as a potential, indirect, source of energy to bears has been overlooked. Here we used the highly branched isoprenoid lipid biomarker-based index (H-Print approach in combination with quantitative fatty acid signature analysis to show that sympagic (sea ice-associated, rather than pelagic, carbon contributions dominated the marine component of polar bear diet (72-100%; 99% CI, n = 55, irrespective of differences in diet composition. The lowest mean estimates of sympagic carbon were found in Baffin Bay bears, which were also exposed to the most rapidly increasing open water season. Therefore, our data illustrate that for future Arctic ecosystems that are likely to be characterised by reduced sea ice cover, polar bears will not only be impacted by a change in their physical habitat, but also potentially in the supply of energy to the ecosystems upon which they depend. This data represents the first quantifiable baseline that is critical for the assessment of likely ongoing changes in energy supply to Arctic predators as we move into an increasingly uncertain future for polar ecosystems.

Improvement of a three-dimensional atmospheric dynamic model and examination of its performance over complex terrain

International Nuclear Information System (INIS)

Nagai, Haruyasu; Yamazawa, Hiromi

1994-11-01

A three-dimensional atmospheric dynamic model (PHYSIC) was improved and its performance was examined using the meteorological data observed at a coastal area with a complex terrain. To introduce synoptic meteorological conditions into the model, the initial and boundary conditions were improved. By this improvement, the model can predict the temporal change of wind field for more than 24 hours. Moreover, the model successfully simulates the land and sea breeze observed at Shimokita area in the summer of 1992. (author)

Predictive Sea State Estimation for Automated Ride Control and Handling - PSSEARCH

Science.gov (United States)

Huntsberger, Terrance L.; Howard, Andrew B.; Aghazarian, Hrand; Rankin, Arturo L.

2012-01-01

PSSEARCH provides predictive sea state estimation, coupled with closed-loop feedback control for automated ride control. It enables a manned or unmanned watercraft to determine the 3D map and sea state conditions in its vicinity in real time. Adaptive path-planning/ replanning software and a control surface management system will then use this information to choose the best settings and heading relative to the seas for the watercraft. PSSEARCH looks ahead and anticipates potential impact of waves on the boat and is used in a tight control loop to adjust trim tabs, course, and throttle settings. The software uses sensory inputs including IMU (Inertial Measurement Unit), stereo, radar, etc. to determine the sea state and wave conditions (wave height, frequency, wave direction) in the vicinity of a rapidly moving boat. This information can then be used to plot a safe path through the oncoming waves. The main issues in determining a safe path for sea surface navigation are: (1) deriving a 3D map of the surrounding environment, (2) extracting hazards and sea state surface state from the imaging sensors/map, and (3) planning a path and control surface settings that avoid the hazards, accomplish the mission navigation goals, and mitigate crew injuries from excessive heave, pitch, and roll accelerations while taking into account the dynamics of the sea surface state. The first part is solved using a wide baseline stereo system, where 3D structure is determined from two calibrated pairs of visual imagers. Once the 3D map is derived, anything above the sea surface is classified as a potential hazard and a surface analysis gives a static snapshot of the waves. Dynamics of the wave features are obtained from a frequency analysis of motion vectors derived from the orientation of the waves during a sequence of inputs. Fusion of the dynamic wave patterns with the 3D maps and the IMU outputs is used for efficient safe path planning.

Movement patterns of juvenile whale sharks tagged at an aggregation site in the Red Sea.

Directory of Open Access Journals (Sweden)

Michael L Berumen

Full Text Available Conservation efforts aimed at the whale shark, Rhincodon typus, remain limited by a lack of basic information on most aspects of its ecology, including global population structure, population sizes and movement patterns. Here we report on the movements of 47 Red Sea whale sharks fitted with three types of satellite transmitting tags from 2009-2011. Most of these sharks were tagged at a single aggregation site near Al-Lith, on the central coast of the Saudi Arabian Red Sea. Individuals encountered at this site were all juveniles based on size estimates ranging from 2.5-7 m total length with a sex ratio of approximately 1∶1. All other known aggregation sites for juvenile whale sharks are dominated by males. Results from tagging efforts showed that most individuals remained in the southern Red Sea and that some sharks returned to the same location in subsequent years. Diving data were recorded by 37 tags, revealing frequent deep dives to at least 500 m and as deep as 1360 m. The unique temperature-depth profiles of the Red Sea confirmed that several whale sharks moved out of the Red Sea while tagged. The wide-ranging horizontal movements of these individuals highlight the need for multinational, cooperative efforts to conserve R. typus populations in the Red Sea and Indian Ocean.

Movement patterns of juvenile whale sharks tagged at an aggregation site in the Red Sea.

Science.gov (United States)

Berumen, Michael L; Braun, Camrin D; Cochran, Jesse E M; Skomal, Gregory B; Thorrold, Simon R

2014-01-01

Conservation efforts aimed at the whale shark, Rhincodon typus, remain limited by a lack of basic information on most aspects of its ecology, including global population structure, population sizes and movement patterns. Here we report on the movements of 47 Red Sea whale sharks fitted with three types of satellite transmitting tags from 2009-2011. Most of these sharks were tagged at a single aggregation site near Al-Lith, on the central coast of the Saudi Arabian Red Sea. Individuals encountered at this site were all juveniles based on size estimates ranging from 2.5-7 m total length with a sex ratio of approximately 1∶1. All other known aggregation sites for juvenile whale sharks are dominated by males. Results from tagging efforts showed that most individuals remained in the southern Red Sea and that some sharks returned to the same location in subsequent years. Diving data were recorded by 37 tags, revealing frequent deep dives to at least 500 m and as deep as 1360 m. The unique temperature-depth profiles of the Red Sea confirmed that several whale sharks moved out of the Red Sea while tagged. The wide-ranging horizontal movements of these individuals highlight the need for multinational, cooperative efforts to conserve R. typus populations in the Red Sea and Indian Ocean.

Movement patterns of juvenile whale sharks tagged at an aggregation site in the Red Sea

KAUST Repository

Berumen, Michael L.

2014-07-30

Conservation efforts aimed at the whale shark, Rhincodon typus, remain limited by a lack of basic information on most aspects of its ecology, including global population structure, population sizes and movement patterns. Here we report on the movements of 47 Red Sea whale sharks fitted with three types of satellite transmitting tags from 2009-2011. Most of these sharks were tagged at a single aggregation site near Al-Lith, on the central coast of the Saudi Arabian Red Sea. Individuals encountered at this site were all juveniles based on size estimates ranging from 2.5-7 m total length with a sex ratio of approximately 1:1. All other known aggregation sites for juvenile whale sharks are dominated by males. Results from tagging efforts showed that most individuals remained in the southern Red Sea and that some sharks returned to the same location in subsequent years. Diving data were recorded by 37 tags, revealing frequent deep dives to at least 500 m and as deep as 1360 m. The unique temperature-depth profiles of the Red Sea confirmed that several whale sharks moved out of the Red Sea while tagged. The wide-ranging horizontal movements of these individuals highlight the need for multinational, cooperative efforts to conserve R. typus populations in the Red Sea and Indian Ocean. © 2014 Berumen et al.

Eddies in the Red Sea: A statistical and dynamical study

KAUST Repository

Zhan, Peng

2014-06-01

Sea level anomaly (SLA) data spanning 1992–2012 were analyzed to study the statistical properties of eddies in the Red Sea. An algorithm that identifies winding angles was employed to detect 4998 eddies propagating along 938 unique eddy tracks. Statistics suggest that eddies are generated across the entire Red Sea but that they are prevalent in certain regions. A high number of eddies is found in the central basin between 18°N and 24°N. More than 87% of the detected eddies have a radius ranging from 50 to 135 km. Both the intensity and relative vorticity scale of these eddies decrease as the eddy radii increase. The averaged eddy lifespan is approximately 6 weeks. AEs and cyclonic eddies (CEs) have different deformation features, and those with stronger intensities are less deformed and more circular. Analysis of long-lived eddies suggests that they are likely to appear in the central basin with AEs tending to move northward. In addition, their eddy kinetic energy (EKE) increases gradually throughout their lifespans. The annual cycles of CEs and AEs differ, although both exhibit significant seasonal cycles of intensity with the winter and summer peaks appearing in February and August, respectively. The seasonal cycle of EKE is negatively correlated with stratification but positively correlated with vertical shear of horizontal velocity and eddy growth rate, suggesting that the generation of baroclinic instability is responsible for the activities of eddies in the Red Sea.

Wind-sea surface temperature-sea ice relationship in the Chukchi-Beaufort Seas during autumn

Science.gov (United States)

Zhang, Jing; Stegall, Steve T.; Zhang, Xiangdong

2018-03-01

Dramatic climate changes, especially the largest sea ice retreat during September and October, in the Chukchi-Beaufort Seas could be a consequence of, and further enhance, complex air-ice-sea interactions. To detect these interaction signals, statistical relationships between surface wind speed, sea surface temperature (SST), and sea ice concentration (SIC) were analyzed. The results show a negative correlation between wind speed and SIC. The relationships between wind speed and SST are complicated by the presence of sea ice, with a negative correlation over open water but a positive correlation in sea ice dominated areas. The examination of spatial structures indicates that wind speed tends to increase when approaching the ice edge from open water and the area fully covered by sea ice. The anomalous downward radiation and thermal advection, as well as their regional distribution, play important roles in shaping these relationships, though wind-driven sub-grid scale boundary layer processes may also have contributions. Considering the feedback loop involved in the wind-SST-SIC relationships, climate model experiments would be required to further untangle the underlying complex physical processes.

Moving toroidal limiter

International Nuclear Information System (INIS)

Ikuta, Kazunari; Miyahara, Akira.

1983-06-01

The concept of the limiter-divertor proposed by Mirnov is extended to a toroidal limiter-divertor (which we call moving toroidal limiter) using the stream of ferromagnetic balls coated with a low Z materials such as plastics, graphite and ceramics. An important advantage of the use of the ferromagnetic materials would be possible soft landing of the balls on a catcher, provided that the temperature of the balls is below Curie point. Moreover, moving toroidal limiter would work as a protector of the first wall not only against the vertical movement of plasma ring but also against the violent inward motion driven by major disruption because the orbit of the ball in the case of moving toroidal limiter distributes over the small major radius side of the toroidal plasma. (author)

Transnational Sea-Ice Transport in a Warmer, More Mobile Arctic

Science.gov (United States)

Newton, R.; Tremblay, B.; Pfirman, S. L.; DeRepentigny, P.

2015-12-01

As the Arctic sea ice thins, summer ice continues to shrink in its area, and multi-year ice becomes rarer, winter ice is not disappearing from the Arctic Basin. Rather, it is ever more dominated by first year ice. And each summer, as the total coverage withdraws, the first year ice is able travel faster and farther, carrying any ice-rafted material with it. Micro-organisms, sediments, pollutants and river runoff all move across the Arctic each summer and are deposited hundreds of kilometers from their origins. Analyzing Arctic sea ice drift patterns in the context of the exclusive economic zones (EEZs) of the Arctic nations raises concerns about the changing fate of "alien" ice which forms within one country's EEZ, then drifts and melts in another country's EEZ. We have developed a new data set from satellite-based ice-drift data that allows us to track groups of ice "pixels" forward from their origin to their destination, or backwards from their melting location to their point of formation. The software has been integrated with model output to extend the tracking of sea ice to include climate projections. Results indicate, for example, that Russian sea ice dominates "imports" to the EEZ of Norway, as expected, but with increasing ice mobility it is also is exported into the EEZs of other countries, including Canada and the United States. Regions of potential conflict are identified, including several national borders with extensive and/or changing transboundary sea ice transport. These data are a starting point for discussion of transborder questions raised by "alien" ice and the material it may import from one nation's EEZ to another's.

Covering Ground: Movement Patterns and Random Walk Behavior in Aquilonastra anomala Sea Stars.

Science.gov (United States)

Lohmann, Amanda C; Evangelista, Dennis; Waldrop, Lindsay D; Mah, Christopher L; Hedrick, Tyson L

2016-10-01

The paths animals take while moving through their environments affect their likelihood of encountering food and other resources; thus, models of foraging behavior abound. To collect movement data appropriate for comparison with these models, we used time-lapse photography to track movements of a small, hardy, and easy-to-obtain organism, Aquilonastra anomala sea stars. We recorded the sea stars in a tank over many hours, with and without a food cue. With food present, they covered less distance, as predicted by theory; this strategy would allow them to remain near food. We then compared the paths of the sea stars to three common models of animal movement: Brownian motion, Lévy walks, and correlated random walks; we found that the sea stars' movements most closely resembled a correlated random walk. Additionally, we compared the search performance of models of Brownian motion, a Lévy walk, and a correlated random walk to that of a model based on the sea stars' movements. We found that the behavior of the modeled sea star walk was similar to that of the modeled correlated random walk and the Brownian motion model, but that the sea star walk was slightly more likely than the other walks to find targets at intermediate distances. While organisms are unlikely to follow an idealized random walk in all details, our data suggest that comparing the effectiveness of an organism's paths to those from theory can give insight into the organism's actual movement strategy. Finally, automated optical tracking of invertebrates proved feasible, and A. anomala was revealed to be a tractable, 2D-movement study system.

The Red Sea and Gulf of Aden Basins

Science.gov (United States)

Bosworth, William; Huchon, Philippe; McClay, Ken

2005-10-01

was slab-pull beneath the Urumieh-Doktar arc on the north side of the narrowing Neotethys. Drag of Arabia by the northward-moving Indian plate across the partially locked northern Owen fracture zone and the position of the Carlsberg oceanic ridge probably also influenced the geometry of the Aden rift. The trigger for the onset of rifting, though, was the impingement of the Afar plume at ˜31 Ma. The Red Sea propagated away from the plume head, perpendicular to the extensional stresses then operating in Arabia, and arrived at the bend in the African-Levant margin, which itself may have been a stress concentration ripe for rifting. The local geometry of the early Red Sea rift was strongly influenced by pre-existing basement structures, and as a consequence followed a complex path from Afar to Suez. Each segment of the rift was initially an asymmetric half graben, with well-defined accommodation zones between sub-basins. In the Gulf of Aden, the positions of accommodation zones were strongly influenced by older Mesozoic rift basins. Early rift structures can be restored to their original contiguous geometries along both the Red Sea and Gulf of Aden conjugate margins. In both basins, present-day shorelines restore to a separation of 40-60 km along most of their lengths. The initial rift basins were 60-80 km in width. Oceanic spreading initiated on the Sheba Ridge east of the Alula-Fartaq fracture zone at ˜19-18 Ma. After stalling at this fracture zone, the ridge probably propagated west into the central Gulf of Aden by ˜16 Ma. This matches the observed termination of syn-tectonic deposition along the onshore Aden margins at approximately the same time. At ˜14 Ma, a transform boundary cut through Sinai and the Levant continental margin, linking the northern Red Sea with the Bitlis-Zagros convergence zone. This corresponded with collision of Arabia and Eurasia, which resulted in a new plate geometry with different boundary forces. Red Sea extension changed from rift

Moving Matters: The Causal Effect of Moving Schools on Student Performance. Working Paper #01-15

Science.gov (United States)

Schwartz, Amy Ellen; Stiefel, Leanna; Cordes, Sarah A.

2015-01-01

The majority of existing research on mobility indicates that students do worse in the year of a school move. This research, however, has been unsuccessful in isolating the causal effects of mobility and often fails to distinguish the heterogeneous impacts of moves, conflating structural moves (mandated by a school's terminal grade) and…

The ACCENT-VOCBAS field campaign on biosphere-atmosphere interactions in a Mediterranean ecosystem of Castelporziano (Rome: site characteristics, climatic and meteorological conditions, and eco-physiology of vegetation

Directory of Open Access Journals (Sweden)

S. Fares

2009-06-01

Full Text Available Biosphere-atmosphere interactions were investigated on a sandy dune Mediterranean ecosystem in a field campaign held in 2007 within the frame of the European Projects ACCENT and VOCBAS. The campaign was carried out in the Presidential estate of Castelporziano, a peri-urban park close to Rome. Former campaigns (e.g. BEMA performed in Castelporziano investigated the emission of biogenic volatile organic compounds (BVOC. These campaigns focused on pseudosteppe and evergreen oak groves whereas the contribution of the largely biodiverse dune vegetation, a prominent component of the Mediterranean ecosystem, was overlooked. While specific aspects of the campaign will be discussed in companion papers, the general climatic and physiological aspects are presented here, together with information regarding BVOC emission from the most common plant species of the dune ecosystem. During the campaign regular air movements were observed, dominated by moderate nocturnal land breeze and diurnal sea breeze. A regular daily increase of ozone concentration in the air was also observed, but daily peaks of ozone were lower than those measured in summer on the same site. The site was ideal as a natural photochemical reactor to observe reaction, transport and deposition processes occurring in the Mediterranean basin, since the sea-land breeze circulation allowed a strong mixing between biogenic and anthropogenic emissions and secondary pollutants. Measurements were run in May, when plant physiological conditions were optimal, in absence of severe drought and heat stress. Foliar rates of photosynthesis and transpiration were as high as generally recorded in unstressed Mediterranean sclerophyllous plants. Most of the plant species emitted high level of monoterpenes, despite measurements being made in a period in which emissions of volatile isoprenoids could be restrained by developmental and environmental factors, such as leaf age and relatively low air temperature

Seismicity and stress state in the South China Sea, Indochina and their vicinity

Science.gov (United States)

Zang, Shaoxian; Wu, Zhongliang; Li, Aibing

1992-02-01

The distribution of earthquakes from 1973 to 1982 in the South China Sea, Indochina and their vicinity was studied using the data from I. S. C. It was found that the earthquakes are mainly concentrated along the boundaries of plates. Beside, some of shallow eartqhuakes are distributed in west part of Burma and the boundary between Burma and China, a few of earthquakes occurred in South China Sea. The features of Benioff zone along the boundaries between India plate, Philippine Sea plate and Eurasia plate were studied. The plate do not coupled well under the Java trench and the Philippine trench. The subducted India plate under Burmese range, Andaman—Nicobar arc moves NNE. The fault plane solutions of earthquakes were studied using the first motions of P wave. The stress state on subduction zones and within the area were deduced from the fault plane solutions and the fault movement. It was found that the direction of principal compression axis of stress is in the NNE in west part of Burma, in S—N in south and middle part of Bruma and Thailand, and in NNE or S—N in the South China Sea. It was also found that the stress state has close relation with the interaction of plates.

Long-distance swimming by polar bears (Ursus maritimus) of the southern Beaufort Sea during years of extensive open water

Science.gov (United States)

2014-01-01

Polar bears (Ursus maritimus Phipps, 1774) depend on sea ice for catching marine mammal prey. Recent sea-ice declines have been linked to reductions in body condition, survival, and population size. Reduced foraging opportunity is hypothesized to be the primary cause of sea-ice-linked declines, but the costs of travel through a deteriorated sea-ice environment also may be a factor. We used movement data from 52 adult female polar bears wearing Global Positioning System (GPS) collars, including some with dependent young, to document long-distance swimming (>50 km) by polar bears in the southern Beaufort and Chukchi seas. During 6 years (2004-2009), we identified 50 long-distance swims by 20 bears. Swim duration and distance ranged from 0.7 to 9.7 days (mean = 3.4 days) and 53.7 to 687.1 km (mean = 154.2 km), respectively. Frequency of swimming appeared to increase over the course of the study. We show that adult female polar bears and their cubs are capable of swimming long distances during periods when extensive areas of open water are present. However, long-distance swimming appears to have higher energetic demands than moving over sea ice. Our observations suggest long-distance swimming is a behavioral response to declining summer sea-ice conditions.

Past and present Aral Sea

Science.gov (United States)

Dukhovniy, Viktor; Stulina, Galina; Eshchanov, Odylbek

2013-04-01

The tragedy of disappearing of Aral Sea is well known to the World. Before and after collapse of Soviet Union, a huge quantity of scientific and popular editions described with grief the situation around the Aral Sea. After the NIS states became independent, World Bank, UNDP, UNEP in proper competition with each other had provided some assessment of the situation through presentation of some small and medium grants, but after 2000, the local population remained alone with own problems. Although on the eyes of the present generation a unique transformation of great water body into deserts took place, the global scientific community did not find forces and financing for real and detail investigation of the processes accompanying the Sea shrinking and land formation. We should acknowledge and give big respect to NATO, later to German Government that through GTZ (now GIZ) - German International Collaboration Agency - and GFZ (Potzdam) paid attention to this area of environment crisis and organized scientific and protective design in the so-called Priaralie - the territory around the drying Sea and delta of the two rivers - Amudarya and Syrdarya. Thank to this assistance, the local specialists in collaboration with limited a number of foreign scientists (N.Aladin, P.Zavialov, Joop de Schutter, Hans Wilps, Hedi Oberhansli) organized significant works for detail socioeconomic, ecological and hydrological assessment situation in Priaralie and on the Aral sea coast. On this base, Ministry of Agriculture and Water resources of Uzbekistan and State Committee of Water resources of Kazakhstan developed a plan of rehabilitation of Amudarya and Syrdarya deltas and started implementation of these projects. If Kazakh water authority moved ahead in wetland restoration faster, a forestation of delta and drying bed of Aral Sea got big success in Uzbek territory. 244 thousands hectares of saxsaul and tamarix were planted for protection of the Priaralie. By request of GTZ SIC, ICWC

Cloud Response to Arctic Sea Ice Loss and Implications for Feedbacks in the CESM1 Climate Model

Science.gov (United States)

Morrison, A.; Kay, J. E.; Chepfer, H.; Guzman, R.; Bonazzola, M.

2017-12-01

Clouds have the potential to accelerate or slow the rate of Arctic sea ice loss through their radiative influence on the surface. Cloud feedbacks can therefore play into Arctic warming as clouds respond to changes in sea ice cover. As the Arctic moves toward an ice-free state, understanding how cloud - sea ice relationships change in response to sea ice loss is critical for predicting the future climate trajectory. From satellite observations we know the effect of present-day sea ice cover on clouds, but how will clouds respond to sea ice loss as the Arctic transitions to a seasonally open water state? In this study we use a lidar simulator to first evaluate cloud - sea ice relationships in the Community Earth System Model (CESM1) against present-day observations (2006-2015). In the current climate, the cloud response to sea ice is well-represented in CESM1: we see no summer cloud response to changes in sea ice cover, but more fall clouds over open water than over sea ice. Since CESM1 is credible for the current Arctic climate, we next assess if our process-based understanding of Arctic cloud feedbacks related to sea ice loss is relevant for understanding future Arctic clouds. In the future Arctic, summer cloud structure continues to be insensitive to surface conditions. As the Arctic warms in the fall, however, the boundary layer deepens and cloud fraction increases over open ocean during each consecutive decade from 2020 - 2100. This study will also explore seasonal changes in cloud properties such as opacity and liquid water path. Results thus far suggest that a positive fall cloud - sea ice feedback exists in the present-day and future Arctic climate.

Observed Sea-Level Changes along the Norwegian Coast

Directory of Open Access Journals (Sweden)

Kristian Breili

2017-07-01

Full Text Available Norway’s national sea level observing system consists of an extensive array of tide gauges, permanent GNSS stations, and lines of repeated levelling. Here, we make use of this observation system to calculate relative sea-level rates and rates corrected for glacial isostatic adjustment (GIA along the Norwegian coast for three different periods, i.e., 1960 to 2010, 1984 to 2014, and 1993 to 2016. For all periods, the relative sea-level rates show considerable spatial variations that are largely due to differences in vertical land motion due to GIA. The variation is reduced by applying corrections for vertical land motion and associated gravitational effects on sea level. For 1960 to 2010 and 1984 to 2014, the coastal average GIA-corrected rates for Norway are 2.0 ± 0.6 mm/year and 2.2 ± 0.6 mm/year, respectively. This is close to the rate of global sea-level rise for the same periods. For the most recent period, 1993 to 2016, the GIA-corrected coastal average is 3.5 ± 0.6 mm/year and 3.2 ± 0.6 mm/year with and without inverse barometer (IB corrections, respectively, which is significantly higher than for the two earlier periods. For 1993 to 2016, the coastal average IB-corrected rates show broad agreement with two independent sets of altimetry. This suggests that there is no systematic error in the vertical land motion corrections applied to the tide-gauge data. At the same time, altimetry does not capture the spatial variation identified in the tide-gauge records. This could be an effect of using altimetry observations off the coast instead of directly at each tide gauge. Finally, we note that, owing to natural variability in the climate system, our estimates are highly sensitive to the selected study period. For example, using a 30-year moving window, we find that the estimated rates may change by up to 1 mm/year when shifting the start epoch by only one year.

On the sensitivity of mesoscale models to surface-layer parameterization constants

Science.gov (United States)

Garratt, J. R.; Pielke, R. A.

1989-09-01

The Colorado State University standard mesoscale model is used to evaluate the sensitivity of one-dimensional (1D) and two-dimensional (2D) fields to differences in surface-layer parameterization “constants”. Such differences reflect the range in the published values of the von Karman constant, Monin-Obukhov stability functions and the temperature roughness length at the surface. The sensitivity of 1D boundary-layer structure, and 2D sea-breeze intensity, is generally less than that found in published comparisons related to turbulence closure schemes generally.

PARALLEL MOVING MECHANICAL SYSTEMS

Directory of Open Access Journals (Sweden)

Florian Ion Tiberius Petrescu

2014-09-01

Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Moving mechanical systems parallel structures are solid, fast, and accurate. Between parallel systems it is to be noticed Stewart platforms, as the oldest systems, fast, solid and precise. The work outlines a few main elements of Stewart platforms. Begin with the geometry platform, kinematic elements of it, and presented then and a few items of dynamics. Dynamic primary element on it means the determination mechanism kinetic energy of the entire Stewart platforms. It is then in a record tail cinematic mobile by a method dot matrix of rotation. If a structural mottoelement consists of two moving elements which translates relative, drive train and especially dynamic it is more convenient to represent the mottoelement as a single moving components. We have thus seven moving parts (the six motoelements or feet to which is added mobile platform 7 and one fixed.

Influence of ice thickness and surface properties on light transmission through Arctic sea ice.

Science.gov (United States)

Katlein, Christian; Arndt, Stefanie; Nicolaus, Marcel; Perovich, Donald K; Jakuba, Michael V; Suman, Stefano; Elliott, Stephen; Whitcomb, Louis L; McFarland, Christopher J; Gerdes, Rüdiger; Boetius, Antje; German, Christopher R

2015-09-01

The observed changes in physical properties of sea ice such as decreased thickness and increased melt pond cover severely impact the energy budget of Arctic sea ice. Increased light transmission leads to increased deposition of solar energy in the upper ocean and thus plays a crucial role for amount and timing of sea-ice-melt and under-ice primary production. Recent developments in underwater technology provide new opportunities to study light transmission below the largely inaccessible underside of sea ice. We measured spectral under-ice radiance and irradiance using the new Nereid Under-Ice (NUI) underwater robotic vehicle, during a cruise of the R/V Polarstern to 83°N 6°W in the Arctic Ocean in July 2014. NUI is a next generation hybrid remotely operated vehicle (H-ROV) designed for both remotely piloted and autonomous surveys underneath land-fast and moving sea ice. Here we present results from one of the first comprehensive scientific dives of NUI employing its interdisciplinary sensor suite. We combine under-ice optical measurements with three dimensional under-ice topography (multibeam sonar) and aerial images of the surface conditions. We investigate the influence of spatially varying ice-thickness and surface properties on the spatial variability of light transmittance during summer. Our results show that surface properties such as melt ponds dominate the spatial distribution of the under-ice light field on small scales (sea ice-thickness is the most important predictor for light transmission on larger scales. In addition, we propose the use of an algorithm to obtain histograms of light transmission from distributions of sea ice thickness and surface albedo.

U.S. Warms to Law of the Sea Treaty

Science.gov (United States)

Showstack, Randy

The United States is moving closer to ratifying the United Nations Convention on the Law of the Sea, with the Bush Administration bestowing its blessings, and a broad spectrum of interest groups expressing support during recent U.S. Senate hearings. They said that the convention, with some minor clarification, supports U.S. defense, homeland security, resource, scientific, and environmental goals. John Turner, assistant secretary of the Bureau of Oceans and International Environmental and Scientific Affairs at the State Department, said that becoming a party to the convention ``represents the highest priority of United States international oceans policy.'' He spoke at a 21 October hearing of the Senate Committee on Foreign Relations.

The Moving image

DEFF Research Database (Denmark)

Hansen, Lennard Højbjerg

2014-01-01

Every day we are presented with bodily expressions in audiovisual media – by anchors, journalists and characters in films for instance. This article explores how body language in the moving image has been and can be approached in a scholarly manner.......Every day we are presented with bodily expressions in audiovisual media – by anchors, journalists and characters in films for instance. This article explores how body language in the moving image has been and can be approached in a scholarly manner....

Moving to Jobs?

OpenAIRE

Dave Maré; Jason Timmins

2003-01-01

This paper examines whether New Zealand residents move from low-growth to high-growth regions, using New Zealand census data from the past three inter-censal periods (covering 1986-2001). We focus on the relationship between employment growth and migration flows to gauge the strength of the relationship and the stability of the relationship over the business cycle. We find that people move to areas of high employment growth, but that the probability of leaving a region is less strongly relate...

Solving the Sea-Level Equation in an Explicit Time Differencing Scheme

Science.gov (United States)

Klemann, V.; Hagedoorn, J. M.; Thomas, M.

2016-12-01

In preparation of coupling the solid-earth to an ice-sheet compartment in an earth-system model, the dependency of initial topography on the ice-sheet history and viscosity structure has to be analysed. In this study, we discuss this dependency and how it influences the reconstruction of former sea level during a glacial cycle. The modelling is based on the VILMA code in which the field equations are solved in the time domain applying an explicit time-differencing scheme. The sea-level equation is solved simultaneously in the same explicit scheme as the viscoleastic field equations (Hagedoorn et al., 2007). With the assumption of only small changes, we neglect the iterative solution at each time step as suggested by e.g. Kendall et al. (2005). Nevertheless, the prediction of the initial paleo topography in case of moving coastlines remains to be iterated by repeated integration of the whole load history. The sensitivity study sketched at the beginning is accordingly motivated by the question if the iteration of the paleo topography can be replaced by a predefined one. This study is part of the German paleoclimate modelling initiative PalMod. Lit:Hagedoorn JM, Wolf D, Martinec Z, 2007. An estimate of global mean sea-level rise inferred from tide-gauge measurements using glacial-isostatic models consistent with the relative sea-level record. Pure appl. Geophys. 164: 791-818, doi:10.1007/s00024-007-0186-7Kendall RA, Mitrovica JX, Milne GA, 2005. On post-glacial sea level - II. Numerical formulation and comparative reesults on spherically symmetric models. Geophys. J. Int., 161: 679-706, doi:10.1111/j.365-246.X.2005.02553.x

Modeled Oceanic Response and Sea Surface Cooling to Typhoon Kai-Tak

Directory of Open Access Journals (Sweden)

Yu-Heng Tseng

2010-01-01

Full Text Available An ocean response to typhoon Kai-Tak is simulated using an accurate fourth-order, basin-scale ocean model. The surface winds of typhoon Kai-Tak were obtained from QuikSCAT satellite images blended with the ECMWF wind fields. An intense nonlinear mesoscale eddy is generated in the northeast South China Sea (SCS with a Rossby number of O(1 and on a 50 - 100 km horizontal scale. Inertial oscillation is clearly observed. Advection dominates as a strong wind shear drives the mixed layer flows outward, away from the typhoon center, thus forcing upwelling from deep levels with a high upwelling velocity (> 30 m day-1. A drop in sea surface temperature (SST of more than 9°C is found in both observation and simulation. We attribute this significant SST drop to the influence of the slow moving typhoon, initial stratification and bathymetry-induced upwelling in the northeast of the SCS where the typhoon hovered.

Impacts of typhoon megi (2010) on the South China Sea

Science.gov (United States)

Ko, Dong Shan; Chao, Shenn-Yu; Wu, Chun-Chieh; Lin, I.-I.

2014-07-01

In October 2010, typhoon Megi induced a profound cold wake of size 800 km by 500 km with sea surface temperature cooling of 8°C in the South China Sea (SCS). More interestingly, the cold wake shifted from the often rightward bias to both sides of the typhoon track and moved to left in a few days. Using satellite data, in situ measurements and numerical modeling based on the East Asian Seas Nowcast/Forecast System (EASNFS), we performed detailed investigations. To obtain realistic typhoon-strength atmospheric forcing, the EASNFS applied typhoon-resolving Weather Research and Forecasting (WRF) model wind field blended with global weather forecast winds from the U.S. Navy Operational Global Atmospheric Prediction System (NOGAPS). In addition to the already known impacts from the slow typhoon translation speed and shallow pre-exiting ocean thermocline, we found the importance of the unique geographical setting of the SCS and the NE monsoon. As the event happened in late October, NE monsoon already started and contributed to the southwestward ambient surface current. Together with the topographicβ effect, the cold wake shifted westward to the left of Megi's track. It was also found that Megi expelled waters away from the SCS and manifested as a gush of internal Kelvin wave exporting waters through the Luzon Strait. The consequential sea level depression lasted and presented a favorable condition for cold dome development. Fission of the north-south elongated cold dome resulted afterward and produced two cold eddies that dissipated slowly thereafter.

Intraseasonal sea surface temperature variability in Indonesian seas

Science.gov (United States)

Napitu, A. M.; Gordon, A. L.; Yuan, X.

2012-12-01

The satellite-derived sea surface temperature (SST) data, 1998-mid 2012, are used to examine intraseasonal variability (ISV; 20-90 days) across the Indonesian seas. The most energetic ISV is observed in the Banda Sea and across the Indo-Australia basin with an The satellite-derived sea surface temperature (SST) data, 1998-mid 2012, are used to examine intraseasonal variability (ISV; 20-90 days) across the Indonesian seas. The most energetic ISV is observed in the Banda Sea and across the Indo-Australia basin with an average SST standard deviation (STD) between 0.4-0.5°C, with strongest signature during boreal winter. What physical processes force the SST ISV variability within the Indonesian seas? Ocean process, sea-air interaction, or both? To help identify the main forcing, the satellite derived outgoing longwave radiation (OLR) and wind stress data in the region are examined. The OLR shows robust intraseasonal variations and is significantly correlated with the SST, particularly for variability with periods of 30-60 days, with OLR accounting for ~60-70% of the SST variance. The OLR is also maximum during boreal winter. Conversely, the surface wind may play insignificant role in perturbing the SST at intraseasonal timescales as shown by weak correlation between wind stress and SST. We thus suspect that the surface solar flux (suggested by the OLR) is likely more dominant than the surface turbulent heat flux (indicated by the surface wind) as the main source for the ISV in the SST in Indonesian seas. Furthermore the maximum OLR phase, coupled with a period of minimum mixed layer depth, may explain the strong SST variation during boreal winter in Indonesian seas. The influence of the Madden-Julian Oscillation (MJO) on the OLR and SST variability is currently being evaluated.

Observational study of atmospheric surface layer and coastal weather in northern Qatar

Science.gov (United States)

Samanta, Dhrubajyoti; Sadr, Reza

2016-04-01

Atmospheric surface layer is the interaction medium between atmosphere and Earth's surface. Better understanding of its turbulence nature is essential in characterizing the local weather, climate variability and modeling of turbulent exchange processes. The importance of Middle East region, with its unique geographical, economical and weather condition is well recognized. However, high quality micrometeorological observational studies are rare in this region. Here we show experimental results from micrometeorological observations from an experimental site in the coastal region of Qatar during August-December 2015. Measurements of winds are obtained from three sonic anemometers installed on a 9 m tower placed at Al Ghariyah beach in northern Qatar (26.08 °N, 51.36 °E). Different surface layer characteristics is analyzed and compared with earlier studies in equivalent weather conditions. Monthly statistics of wind speed, wind direction, temperature, humidity and heat index are made from concurrent observations from sonic anemometer and weather station to explore variations with surface layer characteristics. The results also highlights potential impact of sea breeze circulation on local weather and atmospheric turbulence. The observed daily maximum temperature and heat index during morning period may be related to sea breeze circulations. Along with the operational micrometeorological observation system, a camera system and ultrasonic wave measurement system are installed recently in the site to study coastline development and nearshore wave dynamics. Overall, the complete observational set up is going to provide new insights about nearshore wind dynamics and wind-wave interaction in Qatar.

Minimum Delay Moving Object Detection

KAUST Repository

Lao, Dong

2017-11-09

We present a general framework and method for detection of an object in a video based on apparent motion. The object moves relative to background motion at some unknown time in the video, and the goal is to detect and segment the object as soon it moves in an online manner. Due to unreliability of motion between frames, more than two frames are needed to reliably detect the object. Our method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

Minimum Delay Moving Object Detection

KAUST Repository

Lao, Dong

2017-01-08

We present a general framework and method for detection of an object in a video based on apparent motion. The object moves relative to background motion at some unknown time in the video, and the goal is to detect and segment the object as soon it moves in an online manner. Due to unreliability of motion between frames, more than two frames are needed to reliably detect the object. Our method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

Minimum Delay Moving Object Detection

KAUST Repository

Lao, Dong; Sundaramoorthi, Ganesh

2017-01-01

We present a general framework and method for detection of an object in a video based on apparent motion. The object moves relative to background motion at some unknown time in the video, and the goal is to detect and segment the object as soon it moves in an online manner. Due to unreliability of motion between frames, more than two frames are needed to reliably detect the object. Our method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

Relative sea-level changes and crustal movements in Britain and Ireland since the Last Glacial Maximum

Science.gov (United States)

Shennan, Ian; Bradley, Sarah L.; Edwards, Robin

2018-05-01

The new sea-level database for Britain and Ireland contains >2100 data points from 86 regions and records relative sea-level (RSL) changes over the last 20 ka and across elevations ranging from ∼+40 to -55 m. It reveals radically different patterns of RSL as we move from regions near the centre of the Celtic ice sheet at the last glacial maximum to regions near and beyond the ice limits. Validated sea-level index points and limiting data show good agreement with the broad patterns of RSL change predicted by current glacial isostatic adjustment (GIA) models. The index points show no consistent pattern of synchronous coastal advance and retreat across different regions, ∼100-500 km scale, indicating that within-estuary processes, rather than decimetre- and centennial-scale oscillations in sea level, produce major controls on the temporal pattern of horizontal shifts in coastal sedimentary environments. Comparisons between the database and GIA model predictions for multiple regions provide potentially powerful constraints on various characteristics of global GIA models, including the magnitude of MWP1A, the final deglaciation of the Laurentide ice sheet and the continued melting of Antarctica after 7 ka BP.

Minimum Delay Moving Object Detection

KAUST Repository

Lao, Dong

2017-05-14

This thesis presents a general framework and method for detection of an object in a video based on apparent motion. The object moves, at some unknown time, differently than the “background” motion, which can be induced from camera motion. The goal of proposed method is to detect and segment the object as soon it moves in an online manner. Since motion estimation can be unreliable between frames, more than two frames are needed to reliably detect the object. Observing more frames before declaring a detection may lead to a more accurate detection and segmentation, since more motion may be observed leading to a stronger motion cue. However, this leads to greater delay. The proposed method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms, defined as declarations of detection before the object moves or incorrect or inaccurate segmentation at the detection time. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

Sea-ice evaluation of NEMO-Nordic 1.0: a NEMO-LIM3.6-based ocean-sea-ice model setup for the North Sea and Baltic Sea

Science.gov (United States)

Pemberton, Per; Löptien, Ulrike; Hordoir, Robinson; Höglund, Anders; Schimanke, Semjon; Axell, Lars; Haapala, Jari

2017-08-01

The Baltic Sea is a seasonally ice-covered marginal sea in northern Europe with intense wintertime ship traffic and a sensitive ecosystem. Understanding and modeling the evolution of the sea-ice pack is important for climate effect studies and forecasting purposes. Here we present and evaluate the sea-ice component of a new NEMO-LIM3.6-based ocean-sea-ice setup for the North Sea and Baltic Sea region (NEMO-Nordic). The setup includes a new depth-based fast-ice parametrization for the Baltic Sea. The evaluation focuses on long-term statistics, from a 45-year long hindcast, although short-term daily performance is also briefly evaluated. We show that NEMO-Nordic is well suited for simulating the mean sea-ice extent, concentration, and thickness as compared to the best available observational data set. The variability of the annual maximum Baltic Sea ice extent is well in line with the observations, but the 1961-2006 trend is underestimated. Capturing the correct ice thickness distribution is more challenging. Based on the simulated ice thickness distribution we estimate the undeformed and deformed ice thickness and concentration in the Baltic Sea, which compares reasonably well with observations.

Error Analysis of Fast Moving Target Geo-location in Wide Area Surveillance Ground Moving Target Indication Mode

Directory of Open Access Journals (Sweden)

Zheng Shi-chao

2013-12-01

Full Text Available As an important mode in airborne radar systems, Wide Area Surveillance Ground Moving Target Indication (WAS-GMTI mode has the ability of monitoring a large area in a short time, and then the detected moving targets can be located quickly. However, in real environment, many factors introduce considerable errors into the location of moving targets. In this paper, a fast location method based on the characteristics of the moving targets in WAS-GMTI mode is utilized. And in order to improve the location performance, those factors that introduce location errors are analyzed and moving targets are relocated. Finally, the analysis of those factors is proved to be reasonable by simulation and real data experiments.

Sea level report

International Nuclear Information System (INIS)

Schwartz, M.L.

1979-01-01

Study of Cenozoic Era sea levels shows a continual lowering of sea level through the Tertiary Period. This overall drop in sea level accompanied the Pleistocene Epoch glacio-eustatic fluctuations. The considerable change of Pleistocene Epoch sea level is most directly attributable to the glacio-eustatic factor, with a time span of 10 5 years and an amplitude or range of approximately 200 m. The lowering of sea level since the end of the Cretaceous Period is attributed to subsidence and mid-ocean ridges. The maximum rate for sea level change is 4 cm/y. At present, mean sea level is rising at about 3 to 4 mm/y. Glacio-eustacy and tectono-eustacy are the parameters for predicting sea level changes in the next 1 my. Glacio-eustatic sea level changes may be projected on the basis of the Milankovitch Theory. Predictions about tectono-eustatic sea level changes, however, involve predictions about future tectonic activity and are therefore somewhat difficult to make. Coastal erosion and sedimentation are affected by changes in sea level. Erosion rates for soft sediments may be as much as 50 m/y. The maximum sedimentation accumulation rate is 20 m/100 y

Estimation of PV output power in moving and rocking hybrid energy marine ships

International Nuclear Information System (INIS)

Liu, Hongda; Zhang, Qing; Qi, Xiaoxia; Han, Yang; Lu, Fang

2017-01-01

Highlights: •A mathematical model for characterizing the ship PV output power is developed. •The impacts of the sea condition and ship type on the PV output power are analyzed. •The hybrid energy storage system is used to stabilize the PV fluctuation powers. •A SC configuration method based on maximum half period is applied. -- Abstract: In recent years, the application of solar energy and energy storage to ship power systems has shown promise as a method for both reducing annual carbon and nitrogen oxide emissions and improving ship energy efficiency in the maritime shipping industry. When a ship navigates at sea, it encounters a constant rocking motion that is affected by both the surrounding sea conditions and the ship’s navigation parameters. This motion increases the uncertainty involved in using solar energy and accelerates the aging of the ship’s energy storage battery to some extent. In this study, a universal mathematical model is established for the power generation by photovoltaic (PV) modules in which both the sea conditions and the ship’s integrated motion, including its basic movement along with the motion caused by rocking, are taken into account. Based on this model, the fluctuation characteristics of a ship’s PV output power are studied and determined using three different simulation scenarios. A binary energy storage scheme based on a decoupled PV output power is proposed in order to both stabilize the small-period PV power fluctuations and slow the aging of the actual battery caused by rocking. In addition, a super-capacitor (SC) configuration is constructed based on a maximum half cycle. Finally, the optimal energy storage capacities for this green ship are compared under both rocking and moving motion. In the case of rocking motion, the SCs are able to achieve an approximately 24.8–35.0% reduction in battery replacement. A shipping route between Shanghai, China and Sydney, Australia is considered to validate the practicality

Acoustic Conditioning System Development and Conditioning Experiments on Black Seabreams in the Xiangshan Bay Sea Ranch

Science.gov (United States)

Hu, Qingsong; Rahman, Hafiz Abd ur; Jiang, Yazhou; Zhang, Shouyu; Shentu, Jikang

2018-06-01

Attracting released hatchery-reared fish to designated areas during the growth process is vital to realize the objectives of sea ranching. Based on the bottom artificial reefs and surface kelp culture facilities in the Xiangshan Bay sea ranch, we proposed systematic techniques related to acoustic conditioning of the black seabream ( Sparus macrocephalus). Experiments conducted in 12 m × 10 m × 1.6 m ponds on Xixuan Island showed that black seabream was positively sensitive to 500-600 Hz periodic signals. Conditioned responses were apparent after 8 d. Two to three days were required for recovery of the memory of a conditioned response after a 20-day interval. According to the practical application requirements in the open sea, unattended acoustic conditioning equipment was developed. The ranching equipment was used in 12 m × 12 m × 2.5 m cages, and the behavior of black seabream juveniles was successfully guided after 7 days. Of the 16000 released fish, 82.5% of them were conditioned with a flexible grading net. To avoid inducing a stress response, the juveniles were released into the sea ranch in situ from the net cage. The acoustic conditioning equipments were moved into the open sea and the aggregation phenomenon of the released fish was observed when the sound was played. After 6 months of investigation and based on Sr+ marking, only one acoustically conditioned fish was found outside the 3.5-km2 sea ranch area, thereby reached the goal of guiding activity. The practical effect in the Xiangshan Bay sea ranch showed the validity of the acoustic conditioning system, which may contribute to improve the operation of the sea ranches in the East China Sea.

30 CFR 56.14107 - Moving machine parts.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Moving machine parts. 56.14107 Section 56.14107... Safety Devices and Maintenance Requirements § 56.14107 Moving machine parts. (a) Moving machine parts... takeup pulleys, flywheels, couplings, shafts, fan blades, and similar moving parts that can cause injury...

Reliability on the move: safety and reliability in transportation

International Nuclear Information System (INIS)

Guy, G.B.

1989-01-01

The development of transportation has been a significant factor in the development of civilisation as a whole. Our technical ability to move people and goods now seems virtually limitless when one considers for example the achievements of the various space programmes. Yet our current achievements rely heavily on high standards of safety and reliability from equipment and the human component of transportation systems. Recent failures have highlighted our dependence on equipment and human reliability. This book represents the proceedings of the 1989 Safety and Reliability Society symposium held at Bath on 11-12 October 1989. The structure of the book follows the structure of the symposium itself and the papers selected represent current thinking the the wide field of transportation, and the areas of rail (6 papers, three on railway signalling), air including space (two papers), road (one paper), road and rail (two papers) and sea (three papers) are covered. There are four papers concerned with general transport issues. Three papers concerned with the transport of radioactive materials are indexed separately. (author)

People on the Move

Science.gov (United States)

Mohan, Audrey

2018-01-01

The purpose of this 2-3 day lesson is to introduce students in Grades 2-4 to the idea that people move around the world for a variety of reasons. In this activity, students explore why people move through class discussion, a guided reading, and interviews. The teacher elicits student ideas using the compelling question (Dimension 1 of the C3…

Shear-controlled evolution of the Red Sea: pull apart model

Science.gov (United States)

Makris, J.; Rihm, R.

1991-11-01

Results of seismic and other geophysical investigations suggest that strike-slip processes controlled the break-up of the Arabian plate from Africa and initiated the Red Sea Rift. Early oceanisation was facilitated by nucleation of pull apart basins and massive intrusives. The evolution of the Red Sea has gone through different stages. It was a zone of structural weakness already during the Pan-African orogeny approximately 600 Ma. A major reactivation, however, that gradually led to the present-day configuration was initiated during the late Oligocene with intense magmatic activity and the development of a continental rift. Wrench faulting played a key role in the early evolution of the Red Sea, as it shaped most of its western flank as a sharp plate boundary and resulted in the generation and rapid oceanisation of linearly arranged pull apart basins. Spatial distribution of these basins reflects the geometry of the strike-slip zone, which was controlled by pre-existing fault systems like the Najd Shear System, the Central African Fault Zone or the Onib-Hamisana and Baraka suture zones. Strike-slip motion along the latter zones of weakness influenced mainly the Egyptian and Sudanese coastal areas. Arabia was therefore separated from Africa by oceanisation in those regions, where pull apart basins developed. They were still connected in the in-between segments by stretched continental crust. With Arabia as the "moving" and Africa as the "stable" plate the eastern Red Sea flank was formed by pure shear through stretching, thinning and diffuse extension. As a consequence, the eastern and western flanks of the Red Sea are asymmetrical. The acceleration of the movement of Arabia in early/middle Miocene could no longer be accommodated by the opening in the Gulf of Suez and consequently the Dead Sea strike-slip fault developed approximately 14 Ma ago. Since plate motion was still oblique to the major structural trends, the pull apart evolution on the western flank

The wind sea and swell waves climate in the Nordic seas

Science.gov (United States)

Semedo, Alvaro; Vettor, Roberto; Breivik, Øyvind; Sterl, Andreas; Reistad, Magnar; Soares, Carlos Guedes; Lima, Daniela

2015-02-01

A detailed climatology of wind sea and swell waves in the Nordic Seas (North Sea, Norwegian Sea, and Barents Sea), based on the high-resolution reanalysis NORA10, developed by the Norwegian Meteorological Institute, is presented. The higher resolution of the wind forcing fields, and the wave model (10 km in both cases), along with the inclusion of the bottom effect, allowed a better description of the wind sea and swell features, compared to previous global studies. The spatial patterns of the swell-dominated regional wave fields are shown to be different from the open ocean, due to coastal geometry, fetch dimensions, and island sheltering. Nevertheless, swell waves are still more prevalent and carry more energy in the Nordic Seas, with the exception of the North Sea. The influence of the North Atlantic Oscillation on the winter regional wind sea and swell patterns is also presented. The analysis of the decadal trends of wind sea and swell heights during the NORA10 period (1958-2001) shows that the long-term trends of the total significant wave height (SWH) in the Nordic Seas are mostly due to swell and to the wave propagation effect.

Moving and Being Moved: Implications for Practice.

Science.gov (United States)

Kretchmar, R. Scott

2000-01-01

Uses philosophical writings, a novel about baseball, and a nonfiction work on rowing to analyze levels of meaning in physical activity, showing why three popular methods for enhancing meaning have not succeeded and may have moved some students away from deeper levels of meaning. The paper suggests that using hints taken from the three books could…

Rearrangement moves on rooted phylogenetic networks.

Science.gov (United States)

Gambette, Philippe; van Iersel, Leo; Jones, Mark; Lafond, Manuel; Pardi, Fabio; Scornavacca, Celine

2017-08-01

Phylogenetic tree reconstruction is usually done by local search heuristics that explore the space of the possible tree topologies via simple rearrangements of their structure. Tree rearrangement heuristics have been used in combination with practically all optimization criteria in use, from maximum likelihood and parsimony to distance-based principles, and in a Bayesian context. Their basic components are rearrangement moves that specify all possible ways of generating alternative phylogenies from a given one, and whose fundamental property is to be able to transform, by repeated application, any phylogeny into any other phylogeny. Despite their long tradition in tree-based phylogenetics, very little research has gone into studying similar rearrangement operations for phylogenetic network-that is, phylogenies explicitly representing scenarios that include reticulate events such as hybridization, horizontal gene transfer, population admixture, and recombination. To fill this gap, we propose "horizontal" moves that ensure that every network of a certain complexity can be reached from any other network of the same complexity, and "vertical" moves that ensure reachability between networks of different complexities. When applied to phylogenetic trees, our horizontal moves-named rNNI and rSPR-reduce to the best-known moves on rooted phylogenetic trees, nearest-neighbor interchange and rooted subtree pruning and regrafting. Besides a number of reachability results-separating the contributions of horizontal and vertical moves-we prove that rNNI moves are local versions of rSPR moves, and provide bounds on the sizes of the rNNI neighborhoods. The paper focuses on the most biologically meaningful versions of phylogenetic networks, where edges are oriented and reticulation events clearly identified. Moreover, our rearrangement moves are robust to the fact that networks with higher complexity usually allow a better fit with the data. Our goal is to provide a solid basis for

Rearrangement moves on rooted phylogenetic networks.

Directory of Open Access Journals (Sweden)

Philippe Gambette

2017-08-01

Full Text Available Phylogenetic tree reconstruction is usually done by local search heuristics that explore the space of the possible tree topologies via simple rearrangements of their structure. Tree rearrangement heuristics have been used in combination with practically all optimization criteria in use, from maximum likelihood and parsimony to distance-based principles, and in a Bayesian context. Their basic components are rearrangement moves that specify all possible ways of generating alternative phylogenies from a given one, and whose fundamental property is to be able to transform, by repeated application, any phylogeny into any other phylogeny. Despite their long tradition in tree-based phylogenetics, very little research has gone into studying similar rearrangement operations for phylogenetic network-that is, phylogenies explicitly representing scenarios that include reticulate events such as hybridization, horizontal gene transfer, population admixture, and recombination. To fill this gap, we propose "horizontal" moves that ensure that every network of a certain complexity can be reached from any other network of the same complexity, and "vertical" moves that ensure reachability between networks of different complexities. When applied to phylogenetic trees, our horizontal moves-named rNNI and rSPR-reduce to the best-known moves on rooted phylogenetic trees, nearest-neighbor interchange and rooted subtree pruning and regrafting. Besides a number of reachability results-separating the contributions of horizontal and vertical moves-we prove that rNNI moves are local versions of rSPR moves, and provide bounds on the sizes of the rNNI neighborhoods. The paper focuses on the most biologically meaningful versions of phylogenetic networks, where edges are oriented and reticulation events clearly identified. Moreover, our rearrangement moves are robust to the fact that networks with higher complexity usually allow a better fit with the data. Our goal is to provide

Reasons for Moving in Nonmetro Iowa

OpenAIRE

Burke, Sandra Charvat; Edelman, Mark

2007-01-01

This study highlights the experiences of people who have recently moved to or from 19 selected nonmetropolitan counties of Iowa. This report highlights work, family, community, and housing reasons for moving. The purpose is to increase understanding about why people move so community leaders and citizens can develop actionable strategies for attracting and retaining population.

Investigating Arctic Sea Ice Survivability in the Beaufort Sea

Directory of Open Access Journals (Sweden)

Matthew Tooth

2018-02-01

Full Text Available Arctic sea ice extent has continued to decline in recent years, and the fractional coverage of multi-year sea ice has decreased significantly during this period. The Beaufort Sea region has been the site of much of the loss of multi-year sea ice, and it continues to play a large role in the extinction of ice during the melt season. We present an analysis of the influence of satellite-derived ice surface temperature, ice thickness, albedo, and downwelling longwave/shortwave radiation as well as latitude and airborne snow depth estimates on the change in sea ice concentration in the Beaufort Sea from 2009 to 2016 using a Lagrangian tracking database. Results from this analysis indicate that parcels that melt during summer in the Beaufort Sea reside at lower latitudes and have lower ice thickness at the beginning of the melt season in most cases. The influence of sea ice thickness and snow depth observed by IceBridge offers less conclusive results, with some years exhibiting higher thicknesses/depths for melted parcels. Parcels that melted along IceBridge tracks do exhibit lower latitudes and ice thicknesses, however, which indicates that earlier melt and breakup of ice may contribute to a greater likelihood of extinction of parcels in the summer.

Sea level change

Digital Repository Service at National Institute of Oceanography (India)

Church, J.A.; Clark, P.U.; Cazenave, A.; Gregory, J.M.; Jevrejeva, S.; Levermann, A.; Merrifield, M.A.; Milne, G.A.; Nerem, R.S.; Nunn, P.D.; Payne, A.J.; Pfeffer, W.T.; Stammer, D.; Unnikrishnan, A.S.

This chapter considers changes in global mean sea level, regional sea level, sea level extremes, and waves. Confidence in projections of global mean sea level rise has increased since the Fourth Assessment Report (AR4) because of the improved...

Air-sea exchange studies at the North Sea

NARCIS (Netherlands)

Leeuw, G. de; Eijk, A.M.J. van; Kunz, G.J.; Veefkind, P.J.

1996-01-01

The North Sea can be considered as a local 'inner' sea in which many processes are quite different from these over the open ocean. The surrounding land has a major influence, being the source for man-made aerosols and gases, whereas the North Sea acts as a sink for these. At the same time the North

Sea ice dynamics across the Mid-Pleistocene transition in the Bering Sea.

Science.gov (United States)

Detlef, H; Belt, S T; Sosdian, S M; Smik, L; Lear, C H; Hall, I R; Cabedo-Sanz, P; Husum, K; Kender, S

2018-03-05

Sea ice and associated feedback mechanisms play an important role for both long- and short-term climate change. Our ability to predict future sea ice extent, however, hinges on a greater understanding of past sea ice dynamics. Here we investigate sea ice changes in the eastern Bering Sea prior to, across, and after the Mid-Pleistocene transition (MPT). The sea ice record, based on the Arctic sea ice biomarker IP 25 and related open water proxies from the International Ocean Discovery Program Site U1343, shows a substantial increase in sea ice extent across the MPT. The occurrence of late-glacial/deglacial sea ice maxima are consistent with sea ice/land ice hysteresis and land-glacier retreat via the temperature-precipitation feedback. We also identify interactions of sea ice with phytoplankton growth and ocean circulation patterns, which have important implications for glacial North Pacific Intermediate Water formation and potentially North Pacific abyssal carbon storage.

Slow light in moving media

Science.gov (United States)

Leonhardt, U.; Piwnicki, P.

2001-06-01

We review the theory of light propagation in moving media with extremely low group velocity. We intend to clarify the most elementary features of monochromatic slow light in a moving medium and, whenever possible, to give an instructive simplified picture.

Understanding mechanism of sea cucumber Apostichopus japonicus aestivation: Insights from TMT-based proteomic study.

Science.gov (United States)

Chen, Muyan; Li, Xingke; Zhu, Aijun; Storey, Kenneth B; Sun, Lina; Gao, Tianxiang; Wang, Tianming

2016-09-01

Marine invertebrate aestivation is a unique strategy for summer survival in response to hot marine conditions. The sea cucumber, Apostichopus japonicus, is an excellent model marine invertebrate for studies of environmentally-induced aestivation. In the present study, we used a tandem mass tag (TMT)-coupled LC-MS/MS approach to identify and quantify the global proteome expression profile over the aestivation-arousal cycle of A. japonicus. A total of 3920 proteins were identified from the intestine of sea cucumber. Among them, 630 proteins showed significant differential expression when comparing three conditions of sea cucumbers: non-aestivating (active), deep-aestivation (at least 15days of continuous aestivation), and arousal after aestivation (renewed moving and feeding). Sea cucumbers in deep aestivation showed substantial differentially expressed proteins (143 up-regulated and 267 down-regulated proteins compared with non-aestivating controls). These differentially expressed proteins suggested that protein and phospholipid probably are major fuel sources during hypometabolism and a general attenuation of carbohydrate metabolism was observed during deep aestivation. Differentially expressed proteins also provided the first global picture of a shift in protein synthesis, protein folding, DNA binding, apoptosis, cellular transport and signaling, and cytoskeletal proteins during deep aestivation in sea cucumbers. A comparison of arousal from aestivation with deep aestivation, revealed a general reversal of the changes that occurred in aestivation for most proteins. Western blot detection further validated the significant up-regulation of HSP70 and down-regulation of methyltransferase-like protein 7A-like in deep-aestivation. Our results suggest that there is substantial post-transcriptional regulation of proteins during the aestivation-arousal cycle in sea cucumbers. Copyright © 2016 Elsevier Inc. All rights reserved.

Extreme heat event projections for a coastal megacity

Science.gov (United States)

Ortiz, L. E.; Gonzalez, J.

2017-12-01

As summers become warmer, extreme heat events are expected to increase in intensity, frequency, and duration. Large urban centers may affect these projections by introducing feedbacks between the atmosphere and the built environment through processes involving anthropogenic heat, wind modification, radiation blocking, and others. General circulation models are often run with spatial resolutions in the order of 100 km, limiting their skill at resolving local scale processes and highly spatially varying features such as cities' heterogeneous landscape and mountain topography. This study employs climate simulations using the Weather Research and Forecast (WRF) model coupled with a modified multi-layer urban canopy and building energy model to downscale CESM1 at 1 km horizontal resolution across three time slices (2006-2010, 2075-2079, and 2095-2099) and two projections (RCP 4.5 and 8.5). New York City Metropolitan area, with a population of over 20 million and a complex urban canopy, is used as a case study. The urban canopy model of WRF was modified to include a drag coefficient as a function of the building plant area fraction and the introduction of evaporative cooling systems at building roofs to reject the anthropogenic heat from the buildings, with urban canopy parameters computed from the New York City Property Land-Use Tax-lot Output (PLUTO). Model performance is evaluated against the input model and historical records from airport stations, showing improvement in the statistical characteristics in the downscaled model output. Projection results are presented as spatially distributed anomalies in heat wave frequency, duration, and maximum intensity from the 2006-2010 benchmark period. Results show that local sea-breeze circulations mitigate heat wave impacts, following a positive gradient with increasing distance from the coastline. However, end of century RCP 8.5 projections show the possibility of reversal of this pattern, sea surface temperatures increase

Nordic Seniors on the Move

DEFF Research Database (Denmark)

”I believe that all people need to move about. Actually, some have difficulties in doing so. They stay in their home neighbourhoods where they’ve grown up and feel safe. I can understand that, but my wife and I, we didn’t want that. We are more open to new ideas.” This anthology is about seniors...... on the move. In seven chapters, Nordic researchers from various disciplines, by means of ethnographic methods, attempt to comprehend the phenomenon of Nordic seniors who move to leisure areas in their own or in other countries. The number of people involved in this kind of migratory movement has grown...... above gives voice to one of these seniors, stressing the necessity of moving. The anthology contributes to the international body of literature about later life migration, specifically representing experiences made by Nordic seniors. As shown here, mobility and migration in later life have implications...

ACCELERATION OF SEA LEVEL RISE OVER MALAYSIAN SEAS FROM SATELLITE ALTIMETER

Directory of Open Access Journals (Sweden)

A. I. A. Hamid

2016-09-01

Full Text Available Sea level rise becomes our concern nowadays as a result of variously contribution of climate change that cause by the anthropogenic effects. Global sea levels have been rising through the past century and are projected to rise at an accelerated rate throughout the 21st century. Due to this change, sea level is now constantly rising and eventually will threaten many low-lying and unprotected coastal areas in many ways. This paper is proposing a significant effort to quantify the sea level trend over Malaysian seas based on the combination of multi-mission satellite altimeters over a period of 23 years. Eight altimeter missions are used to derive the absolute sea level from Radar Altimeter Database System (RADS. Data verification is then carried out to verify the satellite derived sea level rise data with tidal data. Eight selected tide gauge stations from Peninsular Malaysia, Sabah and Sarawak are chosen for this data verification. The pattern and correlation of both measurements of sea level anomalies (SLA are evaluated over the same period in each area in order to produce comparable results. Afterwards, the time series of the sea level trend is quantified using robust fit regression analysis. The findings clearly show that the absolute sea level trend is rising and varying over the Malaysian seas with the rate of sea level varies and gradually increase from east to west of Malaysia. Highly confident and correlation level of the 23 years measurement data with an astonishing root mean square difference permits the absolute sea level trend of the Malaysian seas has raised at the rate 3.14 ± 0.12 mm yr-1 to 4.81 ± 0.15 mm yr-1 for the chosen sub-areas, with an overall mean of 4.09 ± 0.12 mm yr-1. This study hopefully offers a beneficial sea level information to be applied in a wide range of related environmental and climatology issue such as flood and global warming.

Acceleration of Sea Level Rise Over Malaysian Seas from Satellite Altimeter

Science.gov (United States)

Hamid, A. I. A.; Din, A. H. M.; Khalid, N. F.; Omar, K. M.

2016-09-01

Sea level rise becomes our concern nowadays as a result of variously contribution of climate change that cause by the anthropogenic effects. Global sea levels have been rising through the past century and are projected to rise at an accelerated rate throughout the 21st century. Due to this change, sea level is now constantly rising and eventually will threaten many low-lying and unprotected coastal areas in many ways. This paper is proposing a significant effort to quantify the sea level trend over Malaysian seas based on the combination of multi-mission satellite altimeters over a period of 23 years. Eight altimeter missions are used to derive the absolute sea level from Radar Altimeter Database System (RADS). Data verification is then carried out to verify the satellite derived sea level rise data with tidal data. Eight selected tide gauge stations from Peninsular Malaysia, Sabah and Sarawak are chosen for this data verification. The pattern and correlation of both measurements of sea level anomalies (SLA) are evaluated over the same period in each area in order to produce comparable results. Afterwards, the time series of the sea level trend is quantified using robust fit regression analysis. The findings clearly show that the absolute sea level trend is rising and varying over the Malaysian seas with the rate of sea level varies and gradually increase from east to west of Malaysia. Highly confident and correlation level of the 23 years measurement data with an astonishing root mean square difference permits the absolute sea level trend of the Malaysian seas has raised at the rate 3.14 ± 0.12 mm yr-1 to 4.81 ± 0.15 mm yr-1 for the chosen sub-areas, with an overall mean of 4.09 ± 0.12 mm yr-1. This study hopefully offers a beneficial sea level information to be applied in a wide range of related environmental and climatology issue such as flood and global warming.

Aerosol meteorology of Maritime Continent for the 2012 7SEAS southwest monsoon intensive study - Part 2: Philippine receptor observations of fine-scale aerosol behavior

Science.gov (United States)

Reid, Jeffrey S.; Lagrosas, Nofel D.; Jonsson, Haflidi H.; Reid, Elizabeth A.; Atwood, Samuel A.; Boyd, Thomas J.; Ghate, Virendra P.; Xian, Peng; Posselt, Derek J.; Simpas, James B.; Uy, Sherdon N.; Zaiger, Kimo; Blake, Donald R.; Bucholtz, Anthony; Campbell, James R.; Chew, Boon Ning; Cliff, Steven S.; Holben, Brent N.; Holz, Robert E.; Hyer, Edward J.; Kreidenweis, Sonia M.; Kuciauskas, Arunas P.; Lolli, Simone; Oo, Min; Perry, Kevin D.; Salinas, Santo V.; Sessions, Walter R.; Smirnov, Alexander; Walker, Annette L.; Wang, Qing; Yu, Liya; Zhang, Jianglong; Zhao, Yongjing

2016-11-01

. Indeed, the Navy Aerosol Analysis and Prediction System (NAAPS) simulations captured longer period aerosol events quite well but largely failed to capture the timing of high-frequency phenomena. Ultimately, the research findings of these cruises demonstrate the real world challenges of satellite-based missions, significant aerosol life cycle questions such as those the future Aerosol/Clouds/Ecosystems (ACE) will investigate, and the importance of small-scale phenomena such as sea breezes, squall lines, and nucleation events embedded within SWM patterns in dominating aerosol life cycle and potential relationships to clouds.

Aerosol Meteorology of Maritime Continent for the 2012 7SEAS Southwest Monsoon Intensive Study - Part 2: Philippine Receptor Observations of Fine-Scale Aerosol Behavior

Science.gov (United States)

Reid, Jeffrey S.; Lagrosas, Nofel D.; Jonsson, Haflidi H.; Reid, Elizabeth A.; Atwood, Samuel A.; Boyd, Thomas J.; Ghate, Virendra P.; Xian, Peng; Posselt, Derek J.; Simpas, James B.;

Temperature, Salinity, Oxygen, Phosphate, pH and Alkalinity data collected in the North Atlantic Ocean, Baltic Sea, Barents Sea, Greenland Sea, North Sea, Norwegian Sea and White Sea from R/Vs Artemovsk, Atlantida, Okeanograf, Professor Rudovits, and ice observations, 1957 - 1995 (NODC Accession 0073674)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, Salinity, Oxygen, Phosphate, pH and Alkalinity data collected in the North Atlantic Ocean, Baltic Sea, Barents Sea, Greenland Sea, North Sea, Norwegian...

A moving experience !

CERN Document Server

2005-01-01

The Transport Service pulled out all the stops and, more specifically, its fleet of moving and lifting equipment for the Discovery Monday on 6 June - a truly moving experience for all the visitors who took part ! Visitors could play at being machine operator, twiddling the controls of a lift truck fitted with a jib to lift a dummy magnet into a wooden mock-up of a beam-line.They had to show even greater dexterity for this game of lucky dip...CERN-style.Those with a head for heights took to the skies 20 m above ground in a telescopic boom lift.Children were allowed to climb up into the operator's cabin - this is one of the cranes used to move the LHC magnets around. Warm thanks to all members of the Transport Service for their participation, especially B. Goicoechea, T. Ilkei, R. Bihery, S. Prodon, S. Pelletier, Y. Bernard, A.  Sallot, B. Pigeard, S. Guinchard, B. Bulot, J. Berrez, Y. Grandjean, A. Bouakkaz, M. Bois, F. Stach, T. Mazzarino and S. Fumey.

Adaptive moving mesh methods for simulating one-dimensional groundwater problems with sharp moving fronts

Science.gov (United States)

Huang, W.; Zheng, Lingyun; Zhan, X.

2002-01-01

Accurate modelling of groundwater flow and transport with sharp moving fronts often involves high computational cost, when a fixed/uniform mesh is used. In this paper, we investigate the modelling of groundwater problems using a particular adaptive mesh method called the moving mesh partial differential equation approach. With this approach, the mesh is dynamically relocated through a partial differential equation to capture the evolving sharp fronts with a relatively small number of grid points. The mesh movement and physical system modelling are realized by solving the mesh movement and physical partial differential equations alternately. The method is applied to the modelling of a range of groundwater problems, including advection dominated chemical transport and reaction, non-linear infiltration in soil, and the coupling of density dependent flow and transport. Numerical results demonstrate that sharp moving fronts can be accurately and efficiently captured by the moving mesh approach. Also addressed are important implementation strategies, e.g. the construction of the monitor function based on the interpolation error, control of mesh concentration, and two-layer mesh movement. Copyright ?? 2002 John Wiley and Sons, Ltd.

First biological measurements of deep-sea corals from the Red Sea.

Science.gov (United States)

Roder, C; Berumen, M L; Bouwmeester, J; Papathanassiou, E; Al-Suwailem, A; Voolstra, C R

2013-10-03

It is usually assumed that metabolic constraints restrict deep-sea corals to cold-water habitats, with 'deep-sea' and 'cold-water' corals often used as synonymous. Here we report on the first measurements of biological characters of deep-sea corals from the central Red Sea, where they occur at temperatures exceeding 20°C in highly oligotrophic and oxygen-limited waters. Low respiration rates, low calcification rates, and minimized tissue cover indicate that a reduced metabolism is one of the key adaptations to prevailing environmental conditions. We investigated four sites and encountered six species of which at least two appear to be undescribed. One species is previously reported from the Red Sea but occurs in deep cold waters outside the Red Sea raising interesting questions about presumed environmental constraints for other deep-sea corals. Our findings suggest that the present understanding of deep-sea coral persistence and resilience needs to be revisited.

First biological measurements of deep-sea corals from the Red Sea.

KAUST Repository

Roder, Cornelia

2013-10-03

It is usually assumed that metabolic constraints restrict deep-sea corals to cold-water habitats, with \\'deep-sea\\' and \\'cold-water\\' corals often used as synonymous. Here we report on the first measurements of biological characters of deep-sea corals from the central Red Sea, where they occur at temperatures exceeding 20°C in highly oligotrophic and oxygen-limited waters. Low respiration rates, low calcification rates, and minimized tissue cover indicate that a reduced metabolism is one of the key adaptations to prevailing environmental conditions. We investigated four sites and encountered six species of which at least two appear to be undescribed. One species is previously reported from the Red Sea but occurs in deep cold waters outside the Red Sea raising interesting questions about presumed environmental constraints for other deep-sea corals. Our findings suggest that the present understanding of deep-sea coral persistence and resilience needs to be revisited.

Moving beyond the age-depth model paradigm in deep-sea palaeoclimate archives: dual radiocarbon and stable isotope analysis on single foraminifera

Science.gov (United States)

Lougheed, Bryan C.; Metcalfe, Brett; Ninnemann, Ulysses S.; Wacker, Lukas

2018-04-01

Late-glacial palaeoclimate reconstructions from deep-sea sediment archives provide valuable insight into past rapid changes in ocean chemistry. Unfortunately, only a small proportion of the ocean floor with sufficiently high sediment accumulation rate (SAR) is suitable for such reconstructions using the long-standing age-depth model approach. We employ ultra-small radiocarbon (14C) dating on single microscopic foraminifera to demonstrate that the long-standing age-depth model method conceals large age uncertainties caused by post-depositional sediment mixing, meaning that existing studies may underestimate total geochronological error. We find that the age-depth distribution of our 14C-dated single foraminifera is in good agreement with existing bioturbation models only after one takes the possibility of Zoophycos burrowing into account. To overcome the problems associated with the age-depth paradigm, we use the first ever dual 14C and stable isotope (δ18O and δ13C) analysis on single microscopic foraminifera to produce a palaeoclimate time series independent of the age-depth paradigm. This new state of the art essentially decouples single foraminifera from the age-depth paradigm to provide multiple floating, temporal snapshots of ocean chemistry, thus allowing for the successful extraction of temporally accurate palaeoclimate data from low-SAR deep-sea archives. This new method can address large geographical gaps in late-glacial benthic palaeoceanographic reconstructions by opening up vast areas of previously disregarded, low-SAR deep-sea archives to research, which will lead to an improved understanding of the global interaction between oceans and climate.

Moving beyond the age–depth model paradigm in deep-sea palaeoclimate archives: dual radiocarbon and stable isotope analysis on single foraminifera

Directory of Open Access Journals (Sweden)

B. C. Lougheed

2018-04-01

Full Text Available Late-glacial palaeoclimate reconstructions from deep-sea sediment archives provide valuable insight into past rapid changes in ocean chemistry. Unfortunately, only a small proportion of the ocean floor with sufficiently high sediment accumulation rate (SAR is suitable for such reconstructions using the long-standing age–depth model approach. We employ ultra-small radiocarbon (14C dating on single microscopic foraminifera to demonstrate that the long-standing age–depth model method conceals large age uncertainties caused by post-depositional sediment mixing, meaning that existing studies may underestimate total geochronological error. We find that the age–depth distribution of our 14C-dated single foraminifera is in good agreement with existing bioturbation models only after one takes the possibility of Zoophycos burrowing into account. To overcome the problems associated with the age–depth paradigm, we use the first ever dual 14C and stable isotope (δ18O and δ13C analysis on single microscopic foraminifera to produce a palaeoclimate time series independent of the age–depth paradigm. This new state of the art essentially decouples single foraminifera from the age–depth paradigm to provide multiple floating, temporal snapshots of ocean chemistry, thus allowing for the successful extraction of temporally accurate palaeoclimate data from low-SAR deep-sea archives. This new method can address large geographical gaps in late-glacial benthic palaeoceanographic reconstructions by opening up vast areas of previously disregarded, low-SAR deep-sea archives to research, which will lead to an improved understanding of the global interaction between oceans and climate.

Phosphorus dynamics in the Black Sea and Baltic Sea

NARCIS (Netherlands)

Dijkstra, N.|info:eu-repo/dai/nl/372617034

2017-01-01

The dynamics of the key nutrient phosphorus (P) in hypoxic and anoxic marine basins are still incompletely understood. This thesis focuses on the cycling of P in two of such basins: the Baltic Sea and the Black Sea. Water column particulates and sediments from the deep basin of the Black Sea were

Poseidon: A marine environmental monitoring, forecasting and information system for the Greek seas

Directory of Open Access Journals (Sweden)

T.H. SOUKISSIAN

2000-06-01

Full Text Available The scope of this work is twofold: i to discuss and analyze some principles, issues and problems related to the development and advancement of Operational Oceanography in Greece and ii to present a real-time monitoring and forecasting system for the Aegean Sea, which is currently under implementation. Operational Oceanography in Greece has become a necessity today, since it can provide aid to find solutions on problems related to societal, economic, environmental and scientific issues. Most of the Greek coastal regions are under pressure, susceptible to damages due to the increasing tendency of the population to move from the inland to the coast, marine environmental pollution, competitive development of the coastal market sector, etc. Moreover, the complex geomorphology of the coastal areas and the interdependence between natural processes and human activities causes significant alterations in this delicate environment. A rational treatment of these problems can be based on integrated coastal zone management (ICZM. An absolutely necessary means for establishing ICZM is the operation of marine moni- toring systems. Such a system ("POSEIDON system" is under implementation by the National Centre for Marine Research. POSEIDON is a comprehensive marine monitoring and forecasting system, that aims to improve environmental surveillance and facilitate sea transport, rescue and safety of life at sea, fishing and aquaculture, protection of the marine ecosystem, etc. POSEIDON is expected to enhance considerably the capabilities to manage, protect and develop the marine resources of the Greek Seas and to promote Greek Operational Oceanography.

Move of ground water

International Nuclear Information System (INIS)

Kimura, Shigehiko

1983-01-01

As a ground water flow which is difficult to explain by Darcy's theory, there is stagnant water in strata, which moves by pumping and leads to land subsidence. This is now a major problem in Japan. Such move on an extensive scale has been investigated in detail by means of 3 H such as from rainfall in addition to ordinary measurement. The move of ground water is divided broadly into that in an unsaturated stratum from ground surface to water-table and that in a saturated stratum below the water-table. The course of the analyses made so far by 3 H contained in water, and the future trend of its usage are described. A flow model of regarding water as plastic fluid and its flow as channel assembly may be available for some flow mechanism which is not possible to explain with Darcy's theory. (Mori, K.)

Aerosol meteorology of Maritime Continent for the 2012 7SEAS southwest monsoon intensive study – Part 2: Philippine receptor observations of fine-scale aerosol behavior

Directory of Open Access Journals (Sweden)

J. S. Reid

2016-11-01

very difficult to model. Indeed, the Navy Aerosol Analysis and Prediction System (NAAPS simulations captured longer period aerosol events quite well but largely failed to capture the timing of high-frequency phenomena. Ultimately, the research findings of these cruises demonstrate the real world challenges of satellite-based missions, significant aerosol life cycle questions such as those the future Aerosol/Clouds/Ecosystems (ACE will investigate, and the importance of small-scale phenomena such as sea breezes, squall lines, and nucleation events embedded within SWM patterns in dominating aerosol life cycle and potential relationships to clouds.

Aerosol meteorology of Maritime Continent for the 2012 7SEAS southwest monsoon intensive study – Part 2: Philippine receptor observations of fine-scale aerosol behavior

Energy Technology Data Exchange (ETDEWEB)

Reid, Jeffrey S.; Lagrosas, Nofel D.; Jonsson, Haflidi H.; Reid, Elizabeth A.; Atwood, Samuel A.; Boyd, Thomas J.; Ghate, Virendra P.; Xian, Peng; Posselt, Derek J.; Simpas, James B.; Uy, Sherdon N.; Zaiger, Kimo; Blake, Donald R.; Bucholtz, Anthony; Campbell, James R.; Chew, Boon Ning; Cliff, Steven S.; Holben, Brent N.; Holz, Robert E.; Hyer, Edward J.; Kreidenweis, Sonia M.; Kuciauskas, Arunas P.; Lolli, Simone; Oo, Min; Perry, Kevin D.; Salinas, Santo V.; Sessions, Walter R.; Smirnov, Alexander; Walker, Annette L.; Wang, Qing; Yu, Liya; Zhang, Jianglong; Zhao, Yongjing

2016-01-01

and very difficult to model. Indeed, the Navy Aerosol Analysis and Prediction System (NAAPS) simulations captured longer period aerosol events quite well but largely failed to capture the timing of high-frequency phenomena. Ultimately, the research findings of these cruises demonstrate the real world challenges of satellite-based missions, significant aerosol life cycle questions such as those the future Aerosol/Clouds/Ecosystems (ACE) will investigate, and the importance of small-scale phenomena such as sea breezes, squall lines, and nucleation events embedded within SWM patterns in dominating aerosol life cycle and potential relationships to clouds.

Student-Centered Coaching: The Moves

Science.gov (United States)

Sweeney, Diane; Harris, Leanna S.

2017-01-01

Student-centered coaching is a highly-effective, evidence-based coaching model that shifts the focus from "fixing" teachers to collaborating with them to design instruction that targets student outcomes. But what does this look like in practice? "Student-Centered Coaching: The Moves" shows you the day-to-day coaching moves that…

Moving Target Photometry Using WISE and NEOWISE

Science.gov (United States)

Wright, Edward L.

2015-01-01

WISE band 1 observations have a significant noise contribution from confusion. The image subtraction done on W0855-0714 by Wright et al. (2014) shows that this noise source can be eliminated for sources that move by much more than the beamsize. This paper describes an analysis that includes a pattern of celestially fixed flux plus a source moving with a known trajectory. This technique allows the confusion noise to be modeled with nuisance parameters and removed even for sources that have not moved by many beamwidths. However, the detector noise is magnified if the motion is too small. Examples of the method applied to fast moving Y dwarfs and slow moving planets will be shown.

Moving beyond the age-depth model paradigm in deep sea palaeoclimate archives: dual radiocarbon and stable isotope analysis on single foraminifera

NARCIS (Netherlands)

Lougheed, Bryan C.; Metcalfe, Brett; Ninnemann, Ulysses S.; Wacker, Lukas

2017-01-01

Late-glacial palaeoclimate reconstructions from deep-sea sediment archives provide valuable insight into past rapid changes in ocean chemistry, but only a small proportion of the ocean floor is suitable for such reconstructions using the existing state-of-the-art using the age-depth approach. We

Anadromous sea lampreys recolonize a Maine coastal river tributary after dam removal

Science.gov (United States)

Hogg, Robert; Coghlan, Stephen M.; Zydlewski, Joseph D.

2013-01-01

Sedgeunkedunk Stream, a third-order tributary to the Penobscot River, Maine, historically supported several anadromous fishes, including the Atlantic Salmon Salmo salar, AlewifeAlosa pseudoharengus, and Sea Lamprey Petromyzon marinus. However, two small dams constructed in the 1800s reduced or eliminated spawning runs entirely. In 2009, efforts to restore marine–freshwater connectivity in the system culminated with removal of the lowermost dam, thus providing access to an additional 4.6 km of lotic habitat. Because Sea Lampreys utilized accessible habitat prior to dam removal, they were chosen as a focal species with which to quantify recolonization. During spawning runs of 2008–2011 (before and after dam removal), individuals were marked with PIT tags and their activity was tracked with daily recapture surveys. Open-population mark–recapture models indicated a fourfold increase in the annual abundance of spawning-phase Sea Lampreys, with estimates rising from 59±4 () before dam removal (2008) to 223±18 and 242±16 after dam removal (2010 and 2011, respectively). Accompanying the marked increase in annual abundance was a greater than fourfold increase in nesting sites: the number of nests increased from 31 in 2008 to 128 and 131 in 2010 and 2011, respectively. During the initial recolonization event (i.e., in 2010), Sea Lampreys took 6 d to move past the former dam site and 9 d to expand into the furthest upstream reaches. Conversely, during the 2011 spawning run, Sea Lampreys took only 3 d to penetrate into the upstream reaches, thus suggesting a potential positive feedback in which larval recruitment into the system may have attracted adult spawners via conspecific pheromone cues. Although more research is needed to verify the migratory pheromone hypothesis, our study clearly demonstrates that small-stream dam removal in coastal river systems has the potential to enhance recovery of declining anadromous fish populations.

Monitoring sea level and sea surface temperature trends from ERS satellites

DEFF Research Database (Denmark)

Andersen, Ole Baltazar; Knudsen, Per; Beckley, B.

2002-01-01

Data from the two ESA satellites ERS-1 and ERS-2 are used in global and regional analysis of sea level and sea surface temperature trends over the last, 7.8 years. T he ERS satellites and in the future the ENVISAT satellite provide unique opportunity for monitoring both changes in sea level and sea...

Landfast sea ice break-out events in the Chukchi Sea: Two case studies illuminating long-term observations at Barrow, Alaska

Science.gov (United States)

Jones, J.; Eicken, H.; Mahoney, A. R.; Mv, R.; Kambhamettu, C.; Fukamachi, Y.; Ohshima, K. I.

2012-12-01

causal mechanisms for the two break-outs. The February 27 break-out appears driven by strong ocean currents, moving ice almost directly into the wind. In the March 24 break-out, the movement of the ice was in agreement with the dominant wind direction. Both events are associated with a drop in sea level. Further research will provide information on the relative contribution of different forces to the break-out in overcoming stabilizing features of a landfast ice cover.

Analysis on an illusion unexpected occurred on a moving statue leaving in fact but approaching by environmental judgment

Science.gov (United States)

He, Youwu; Li, Zhifang; Qiu, Yishen; Li, Hui

2017-08-01

Earlier this year we visited Sanya, Hainan Province, China. There is a huge statue, the South Sea Avalokitesvara (南海观世音菩萨), at Sanya Nanshan Buddhism Cultural Tourism Resort. When we were gazing at the statue on a leaving car on gradually rising road, an unexpected visual illusion took place in which the statue seemed running after us. In this presentation, an optical model is developed to explain the illusion occurred on a moving object leaving in fact but approaching by environmental judgement. Such an interesting illusion analysis will play a significant role in having students understood the main principles in geometrical optics.

Advances in deep-sea biology: biodiversity, ecosystem functioning and conservation. An introduction and overview

Science.gov (United States)

Cunha, Marina R.; Hilário, Ana; Santos, Ricardo S.

2017-03-01

Once considered as monotonous and devoid of life, the deep sea was revealed during the last century as an environment with a plethora of life forms and extremely high species richness (Rex and Etter, 2010). Underwater vehicle developments allowed direct observations of the deep, disclosing unique habitats and diverse seascapes, and other technological advances enabled manipulative experimentation and unprecedented prospects to pursue novel research topics (Levin and Sibuet, 2012; Danovaro et al., 2014). Alongside, the growing human population greatly increased the pressure on deep-sea ecosystems and the services they provide (Ramirez-Llodra et al., 2011; Thurber et al., 2014; Levin et al., 2016). Societal changes further intensified worldwide competition for natural resources, extending the present footprint of impacts over most of the global ocean (Halpern et al., 2008). In this socio-economic context, and in tandem with cutting edge technological advances and an unclear legal framework to regulate access to natural resources (Boyes and Elliott, 2014), the deep sea has emerged as a new opportunity for industrial exploitation and novel economic activities. The expanding use of the deep sea prompted a rapid reply from deep-sea scientists that recommended "a move from a frontier mentality of exploitation and single-sector management to a precautionary system that balances use of living marine resources, energy, and minerals from the deep ocean with maintenance of a productive and healthy marine environment, while improving knowledge and collaboration" and proposed "three directions to advance deep-ocean stewardship: i) protection and mitigation, ii) research, and iii) collaborative governance" (Mengerink et al., 2014). The European Marine Board position paper 22 (Rogers et al., 2015) further examined the key societal and environmental drivers confronting the deep sea and the role of deep-sea research to deliver future knowledge needs for science and society; a clear

Trading Fees and Slow-Moving Capital

OpenAIRE

Buss, Adrian; Dumas, Bernard J

2015-01-01

In some situations, investment capital seems to move slowly towards profitable trades. We develop a model of a financial market in which capital moves slowly simply because there is a proportional cost to moving capital. We incorporate trading fees in an infinite-horizon dynamic general-equilibrium model in which investors optimally and endogenously decide when and how much to trade. We determine the steady-state equilibrium no-trade zone, study the dynamics of equilibrium trades and prices a...

Winter sea ice export from the Laptev Sea preconditions the local summer sea ice cover and fast ice decay

Directory of Open Access Journals (Sweden)

P. Itkin

2017-10-01

Full Text Available Ice retreat in the eastern Eurasian Arctic is a consequence of atmospheric and oceanic processes and regional feedback mechanisms acting on the ice cover, both in winter and summer. A correct representation of these processes in numerical models is important, since it will improve predictions of sea ice anomalies along the Northeast Passage and beyond. In this study, we highlight the importance of winter ice dynamics for local summer sea ice anomalies in thickness, volume and extent. By means of airborne sea ice thickness surveys made over pack ice areas in the south-eastern Laptev Sea, we show that years of offshore-directed sea ice transport have a thinning effect on the late-winter sea ice cover. To confirm the preconditioning effect of enhanced offshore advection in late winter on the summer sea ice cover, we perform a sensitivity study using a numerical model. Results verify that the preconditioning effect plays a bigger role for the regional ice extent. Furthermore, they indicate an increase in volume export from the Laptev Sea as a consequence of enhanced offshore advection, which has far-reaching consequences for the entire Arctic sea ice mass balance. Moreover we show that ice dynamics in winter not only preconditions local summer ice extent, but also accelerate fast-ice decay.

Processes driving sea ice variability in the Bering Sea in an eddying ocean/sea ice model: Mean seasonal cycle

Science.gov (United States)

Li, Linghan; McClean, Julie L.; Miller, Arthur J.; Eisenman, Ian; Hendershott, Myrl C.; Papadopoulos, Caroline A.

2014-12-01

The seasonal cycle of sea ice variability in the Bering Sea, together with the thermodynamic and dynamic processes that control it, are examined in a fine resolution (1/10°) global coupled ocean/sea-ice model configured in the Community Earth System Model (CESM) framework. The ocean/sea-ice model consists of the Los Alamos National Laboratory Parallel Ocean Program (POP) and the Los Alamos Sea Ice Model (CICE). The model was forced with time-varying reanalysis atmospheric forcing for the time period 1970-1989. This study focuses on the time period 1980-1989. The simulated seasonal-mean fields of sea ice concentration strongly resemble satellite-derived observations, as quantified by root-mean-square errors and pattern correlation coefficients. The sea ice energy budget reveals that the seasonal thermodynamic ice volume changes are dominated by the surface energy flux between the atmosphere and the ice in the northern region and by heat flux from the ocean to the ice along the southern ice edge, especially on the western side. The sea ice force balance analysis shows that sea ice motion is largely associated with wind stress. The force due to divergence of the internal ice stress tensor is large near the land boundaries in the north, and it is small in the central and southern ice-covered region. During winter, which dominates the annual mean, it is found that the simulated sea ice was mainly formed in the northern Bering Sea, with the maximum ice growth rate occurring along the coast due to cold air from northerly winds and ice motion away from the coast. South of St Lawrence Island, winds drive the model sea ice southwestward from the north to the southwestern part of the ice-covered region. Along the ice edge in the western Bering Sea, model sea ice is melted by warm ocean water, which is carried by the simulated Bering Slope Current flowing to the northwest, resulting in the S-shaped asymmetric ice edge. In spring and fall, similar thermodynamic and dynamic

Sea Surface Height Variability and Eddy Statistical Properties in the Red Sea

KAUST Repository

Zhan, Peng

2013-01-01

Satellite sea surface height (SSH) data over 1992-2012 are analyzed to study the spatial and temporal variability of sea level in the Red Sea. Empirical orthogonal functions (EOF) analysis suggests the remarkable seasonality of SSH in the Red Sea

Highly variable Pliocene sea surface conditions in the Norwegian Sea

Directory of Open Access Journals (Sweden)

P. E. Bachem

2017-09-01

Full Text Available The Pliocene was a time of global warmth with small sporadic glaciations, which transitioned towards the larger-scale Pleistocene glacial–interglacial variability. Here, we present high-resolution records of sea surface temperature (SST and ice-rafted debris (IRD in the Norwegian Sea from 5.32 to 3.14 Ma, providing evidence that the Pliocene surface conditions of the Norwegian Sea underwent a series of transitions in response to orbital forcing and gateway changes. Average SSTs are 2 °C above the regional Holocene mean, with notable variability on millennial to orbital timescales. Both gradual changes and threshold effects are proposed for the progression of regional climate towards the Late Pliocene intensification of Northern Hemisphere glaciation. Cooling from 4.5 to 4.3 Ma may be linked to the onset of poleward flow through the Bering Strait. This cooling was further intensified by a period of cool summers due to weak obliquity forcing. A 7 °C warming of the Norwegian Sea at 4.0 Ma suggests a major increase in northward heat transport from the North Atlantic, leading to an enhanced zonal SST gradient in the Nordic Seas, which may be linked to the expansion of sea ice in the Arctic and Nordic Seas. A warm Norwegian Sea and enhanced zonal temperature gradient between 4.0 and 3.6 Ma may have been a priming factor for increased glaciation around the Nordic Seas due to enhanced evaporation and precipitation at high northern latitudes.

Contemporary Arctic Sea Level

Science.gov (United States)

Cazenave, A. A.

2017-12-01

During recent decades, the Arctic region has warmed at a rate about twice the rest of the globe. Sea ice melting is increasing and the Greenland ice sheet is losing mass at an accelerated rate. Arctic warming, decrease in the sea ice cover and fresh water input to the Arctic ocean may eventually impact the Arctic sea level. In this presentation, we review our current knowledge of contemporary Arctic sea level changes. Until the beginning of the 1990s, Arctic sea level variations were essentially deduced from tide gauges located along the Russian and Norwegian coastlines. Since then, high inclination satellite altimetry missions have allowed measuring sea level over a large portion of the Arctic Ocean (up to 80 degree north). Measuring sea level in the Arctic by satellite altimetry is challenging because the presence of sea ice cover limits the full capacity of this technique. However adapted processing of raw altimetric measurements significantly increases the number of valid data, hence the data coverage, from which regional sea level variations can be extracted. Over the altimetry era, positive trend patterns are observed over the Beaufort Gyre and along the east coast of Greenland, while negative trends are reported along the Siberian shelf. On average over the Arctic region covered by satellite altimetry, the rate of sea level rise since 1992 is slightly less than the global mea sea level rate (of about 3 mm per year). On the other hand, the interannual variability is quite significant. Space gravimetry data from the GRACE mission and ocean reanalyses provide information on the mass and steric contributions to sea level, hence on the sea level budget. Budget studies show that regional sea level trends over the Beaufort Gyre and along the eastern coast of Greenland, are essentially due to salinity changes. However, in terms of regional average, the net steric component contributes little to the observed sea level trend. The sea level budget in the Arctic

30 CFR 57.14107 - Moving machine parts.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Moving machine parts. 57.14107 Section 57.14107... Equipment Safety Devices and Maintenance Requirements § 57.14107 Moving machine parts. (a) Moving machine parts shall be guarded to protect persons from contacting gears, sprockets, chains, drive, head, tail...

Lattice Boltzmann methods for moving boundary flows

International Nuclear Information System (INIS)

Inamuro, Takaji

2012-01-01

The lattice Boltzmann methods (LBMs) for moving boundary flows are presented. The LBM for two-phase fluid flows with the same density and the LBM combined with the immersed boundary method are described. In addition, the LBM on a moving multi-block grid is explained. Three numerical examples (a droplet moving in a constricted tube, the lift generation of a flapping wing and the sedimentation of an elliptical cylinder) are shown in order to demonstrate the applicability of the LBMs to moving boundary problems. (invited review)

Lattice Boltzmann methods for moving boundary flows

Energy Technology Data Exchange (ETDEWEB)

Inamuro, Takaji, E-mail: inamuro@kuaero.kyoto-u.ac.jp [Department of Aeronautics and Astronautics, and Advanced Research Institute of Fluid Science and Engineering, Graduate School of Engineering, Kyoto University, Kyoto 606-8501 (Japan)

2012-04-01

The lattice Boltzmann methods (LBMs) for moving boundary flows are presented. The LBM for two-phase fluid flows with the same density and the LBM combined with the immersed boundary method are described. In addition, the LBM on a moving multi-block grid is explained. Three numerical examples (a droplet moving in a constricted tube, the lift generation of a flapping wing and the sedimentation of an elliptical cylinder) are shown in order to demonstrate the applicability of the LBMs to moving boundary problems. (invited review)

Sea Surface Temperature and Ocean Color Variability in the South China Sea

Science.gov (United States)

Conaty, A. P.

2001-12-01

The South China Sea is a marginal sea in the Southeast Asian region whose surface circulation is driven by monsoons and whose surface currents have complex seasonal patterns. Its rich natural resources and strategic location have made its small islands areas of political dispute among the neighboring nations. This study aims to show the seasonal and interannual variability of sea surface temperature and ocean color in South China Sea. It makes use of NOAA's Advanced Very High Resolution Radiometer (AVHRR) satellite data sets on sea surface temperature for the period 1981-2000 and NASA's Nimbus-7 Coastal Zone Color Scanner (CZCS) and Sea-viewing Wide Field-of-view Sensor (SeaWiFS) satellite data sets on pigment concentration (ocean color) for the period 1981-1996 and 1997-2000, respectively. Transect lines were drawn along several potential hotspot areas to show the variability in sea surface temperature and pigment concentration through time. In-situ data on sea surface temperature along South China Sea were likewise plotted to see the variability with time. Higher seasonal variability in sea surface temperature was seen at higher latitudes. Interannual variability was within 1-3 Kelvin. In most areas, pigment concentration was higher during northern hemisphere winter and autumn, after the monsoon rains, with a maximum of 30 milligrams per cubic meter.

Numerical study of the effects of local atmospheric circulations on a pollution event over Beijing-Tianjin-Hebei, China.

Science.gov (United States)

Miao, Yucong; Liu, Shuhua; Zheng, Yijia; Wang, Shu; Chen, Bicheng; Zheng, Hui; Zhao, Jingchuan

2015-04-01

Currently, the Chinese central government is considering plans to build a trilateral economic sphere in the Bohai Bay area, including Beijing, Tianjin and Hebei (BTH), where haze pollution frequently occurs. To achieve sustainable development, it is necessary to understand the physical mechanism of the haze pollution there. Therefore, the pollutant transport mechanisms of a haze event over the BTH region from 23 to 24 September 2011 were studied using the Weather Research and Forecasting model and the FLEXible-PARTicle dispersion model to understand the effects of the local atmospheric circulations and atmospheric boundary layer structure. Results suggested that the penetration by sea-breeze could strengthen the vertical dispersion by lifting up the planetary boundary layer height (PBLH) and carry the local pollutants to the downstream areas; in the early night, two elevated pollution layers (EPLs) may be generated over the mountain areas: the pollutants in the upper EPL at the altitude of 2-2.5 km were favored to disperse by long-range transport, while the lower EPL at the altitude of 1 km may serve as a reservoir, and the pollutants there could be transported downward and contribute to the surface air pollution. The intensity of the sea-land and mountain-valley breeze circulations played an important role in the vertical transport and distribution of pollutants. It was also found that the diurnal evolution of the PBLH is important for the vertical dispersion of the pollutants, which is strongly affected by the local atmospheric circulations and the distribution of urban areas. Copyright © 2015. Published by Elsevier B.V.

Vulnerability of marginal seas to sea level rise

Science.gov (United States)

Gomis, Damia; Jordà, Gabriel

2017-04-01

Sea level rise (SLR) is a serious thread for coastal areas and has a potential negative impact on society and economy. SLR can lead for instance to land loss, beach reduction, increase of the damage of marine storms on coastal infrastructures and to the salinization of underground water streams. It is well acknowledged that future SLR will be inhomogeneous across the globe, with regional differences of up to 100% with respect to global mean sea level (GMSL). Several studies have addressed the projections of SLR at regional scale, but most of them are based on global climate models (GCMs) that have a relatively coarse spatial resolution (>1°). In marginal seas this has proven to be a strong limitation, as their particular configurations require spatial resolutions that are not reachable by present GCMs. A paradigmatic case is the Mediterranean Sea, connected to the global ocean through the Strait of Gibraltar, a narrow passage of 14 km width. The functioning of the Mediterranean Sea involves a variety of processes including an overturning circulation, small-scale convection and a rich mesoscale field. Moreover, the long-term evolution of Mediterranean sea level has been significantly different from the global mean during the last decades. The observations of present climate and the projections for the next decades have lead some authors to hypothesize that the particular characteristics of the basin could allow Mediterranean mean sea level to evolve differently from the global mean. Assessing this point is essential to undertake proper adaptation strategies for the largely populated Mediterranean coastal areas. In this work we apply a new approach that combines regional and global projections to analyse future SLR. In a first step we focus on the quantification of the expected departures of future Mediterranean sea level from GMSL evolution and on the contribution of different processes to these departures. As a result we find that, in spite of its particularities

Deep-sea Hexactinellida (Porifera) of the Weddell Sea

Science.gov (United States)

Janussen, Dorte; Tabachnick, Konstantin R.; Tendal, Ole S.

2004-07-01

New Hexactinellida from the deep Weddel Sea are described. This moderately diverse hexactinellid fauna includes 14 species belonging to 12 genera, of which five species and one subgenus are new to science: Periphragella antarctica n. sp., Holascus pseudostellatus n. sp., Caulophacus (Caulophacus) discohexactinus n. sp., C. ( Caulodiscus) brandti n. sp., C. ( Oxydiscus) weddelli n. sp., and C. ( Oxydiscus) n. subgen. So far, 20 hexactinellid species have been reported from the deep Weddell Sea, 15 are known from the northern part and 10 only from here, while 10 came from the southern area, and five of these only from there. However, this apparent high "endemism" of Antarctic hexactinellid sponges is most likely the result of severe undersampling of the deep-sea fauna. We find no reason to believe that a division between an oceanic and a more continental group of species exists. The current poor database indicates that a substantial part of the deep hexactinellid fauna of the Weddell Sea is shared with other deep-sea regions, but it does not indicate a special biogeographic relationship with any other ocean.

Sea Ice Drift Monitoring in the Bohai Sea Based on GF4 Satellite

Science.gov (United States)

Zhao, Y.; Wei, P.; Zhu, H.; Xing, B.

2018-04-01

The Bohai Sea is the inland sea with the highest latitude in China. In winter, the phenomenon of freezing occurs in the Bohai Sea due to frequent cold wave influx. According to historical records, there have been three serious ice packs in the Bohai Sea in the past 50 years which caused heavy losses to our economy. Therefore, it is of great significance to monitor the drift of sea ice and sea ice in the Bohai Sea. The GF4 image has the advantages of short imaging time and high spatial resolution. Based on the GF4 satellite images, the three methods of SIFT (Scale invariant feature - the transform and Scale invariant feature transform), MCC (maximum cross-correlation method) and sift combined with MCC are used to monitor sea ice drift and calculate the speed and direction of sea ice drift, the three calculation results are compared and analyzed by using expert interpretation and historical statistical data to carry out remote sensing monitoring of sea ice drift results. The experimental results show that the experimental results of the three methods are in accordance with expert interpretation and historical statistics. Therefore, the GF4 remote sensing satellite images have the ability to monitor sea ice drift and can be used for drift monitoring of sea ice in the Bohai Sea.

77 FR 16566 - Submission for OMB Review, Comment Request, Proposed Collection: Let's Move Museums, Let's Move...

Science.gov (United States)

2012-03-21

..., Proposed Collection: Let's Move Museums, Let's Move Gardens AGENCY: Institute of Museum and Library..., comment request. SUMMARY: The Institute of Museum and Library Services announces that the following... functions of the agency, including whether the information will have practical utility; Evaluate the...

Seasonal variation of deep-sea bioluminescence in the Ionian Sea

International Nuclear Information System (INIS)

Craig, Jessica; Jamieson, Alan J.; Bagley, Philip M.; Priede, Imants G.

2011-01-01

The ICDeep (Image Intensified Charge Coupled Device for Deep sea research) profiler was used to measure the density of deep bioluminescent animals (BL) through the water column in the east, west and mid-Ionian Sea and in the Algerian Basin. A west to east decrease in BL density was found. Generalized additive modelling was used to investigate seasonal variation in the east and west Ionian Sea (NESTOR and NEMO neutrino telescope sites, respectively) from BL measurements in autumn 2008 and spring 2009. A significant seasonal effect was found in the west Ionian Sea (p<0.001), where a deep autumnal peak in BL density occurred between 500 and 2400 m. No significant seasonal variation in BL density was found in the east Ionian Sea (p=0.07). In both spring and autumn, significant differences in BL density were found through the water column between the east and west Ionian Sea (p<0.001).

Seasonal variation of deep-sea bioluminescence in the Ionian Sea

Energy Technology Data Exchange (ETDEWEB)

Craig, Jessica, E-mail: j.craig@abdn.ac.u [University of Aberdeen, Oceanlab, Main Street, Newburgh, Aberdeenshire, AB41 6AA (United Kingdom); Jamieson, Alan J.; Bagley, Philip M.; Priede, Imants G. [University of Aberdeen, Oceanlab, Main Street, Newburgh, Aberdeenshire, AB41 6AA (United Kingdom)

2011-01-21

The ICDeep (Image Intensified Charge Coupled Device for Deep sea research) profiler was used to measure the density of deep bioluminescent animals (BL) through the water column in the east, west and mid-Ionian Sea and in the Algerian Basin. A west to east decrease in BL density was found. Generalized additive modelling was used to investigate seasonal variation in the east and west Ionian Sea (NESTOR and NEMO neutrino telescope sites, respectively) from BL measurements in autumn 2008 and spring 2009. A significant seasonal effect was found in the west Ionian Sea (p<0.001), where a deep autumnal peak in BL density occurred between 500 and 2400 m. No significant seasonal variation in BL density was found in the east Ionian Sea (p=0.07). In both spring and autumn, significant differences in BL density were found through the water column between the east and west Ionian Sea (p<0.001).

Baltic Sea coastal erosion; a case study from the Jastrzębia Góra region

Directory of Open Access Journals (Sweden)

Uścinowicz Grzegorz

2014-12-01

Full Text Available The coastline in the Jastrzębia Góra area can be divided into three major zones of general importance: a beach and barrier section, a cliff section, and a section protected by a heavy hydrotechnical construction. These areas are characterised by a diverse geology and origin, and hence different vulnerability to erosion. In addition, observations have demonstrated a different pace of erosion within each zone. Based on the results obtained by remote sensing methods (analysis of aerial photographs and maps, it has been determined that the coastline in the barrier area, i.e., to the west of Jastrzębia Góra, moved landwards by about 130 m, in a period of 100 years, and 80 m over about 50 years. A smaller displacement of the shoreline could be observed within the cliff. Between the middle of the twentieth and the start of the twenty-first centuries the shore retreated by about 25 m. However, in recent years, an active landslide has led to the displacement of the uppermost part of the cliff locally up to 25 m. Another issue is, functioning since 2000, a heavy hydrotechnical construction which has been built in order to protect the most active part of the cliff. The construction is not stable and its western part, over a distance of 50 m, has moved almost 2 m vertically downwards and c. 2.5 m horizontally towards the sea in the past two years. This illustrates that the erosional factor does not comprise only marine abrasion, but also involves land-based processes determined by geology and hydrogeology. Changes in the shoreline at the beach and barrier part are constantly conditioned by rising sea levels, the slightly sloping profile of the sea floor and low elevation values of the backshore and dune areas. Cliffs are destroyed by mass wasting and repetitive storm surges that are responsible for the removal of the colluvium which protects the coast from adverse wave effects. Presumably, mass movements combined with groundwater outflow from the cliff

INTERSPECIFIC AGGRESSIVE BEHAVIOR OF THE CORALLIMORPHARIAN CORYNACTIS CALIFORNICA (CNIDARIA: ANTHOZOA): EFFECTS ON SYMPATRIC CORALS AND SEA ANEMONES.

Science.gov (United States)

Chadwick, Nanette E

1987-08-01

Corallimorpharians are sessile cnidarians that are morphologically similar to the actiniarian sea anemones and scleractinian corals. This study describes for the first time the behavioral mechanism and effects of aggression by a corallimorpharian. Polyps of the temperate clonal corallimorpharian Corynactis californica extruded their mesenteries and associated filaments onto members of certain species of sea anemones and corals. They did not exhibit this behavior intraspecifically, and members of different clones of C. californica remained expanded upon contact. In contrast, members of four species of corals and zoanthids responded to contact with C. californica by contracting their tentacles, and members of three sea anemone species bent or moved away, detached from the substrate, or attacked using their aggressive structures. When interspecific contact was prolonged, individuals of C. californica extruded filaments onto, and killed polyps of, the sea anemones Anthopleura elegantissima and Metridium senile within 3 weeks, and the corals Astrangia lajollaensis and Balanophyllia elegans within 4-10 months under laboratory conditions. The use of extruded mesenterial filaments by C. californica to attack members of other anthozoan species is similar to the aggressive behavior exhibited by many scleractinian reef corals. Field observations suggest that C. californica may use this agonistic behavior during interspecific competition for space on hard marine substrate.

Deep-sea geohazards in the South China Sea

Science.gov (United States)

Wu, Shiguo; Wang, Dawei; Völker, David

2018-02-01

Various geological processes and features that might inflict hazards identified in the South China Sea by using new technologies and methods. These features include submarine landslides, pockmark fields, shallow free gas, gas hydrates, mud diapirs and earthquake tsunami, which are widely distributed in the continental slope and reefal islands of the South China Sea. Although the study and assessment of geohazards in the South China Sea came into operation only recently, advances in various aspects are evolving at full speed to comply with National Marine Strategy and `the Belt and Road' Policy. The characteristics of geohazards in deep-water seafloor of the South China Sea are summarized based on new scientific advances. This progress is aimed to aid ongoing deep-water drilling activities and decrease geological risks in ocean development.

50 CFR 697.12 - At-sea sea sampler/observer coverage.

Science.gov (United States)

2010-10-01

... sampler/observer access to and use of the vessel's communications equipment and personnel upon request for...) Allow the sea sampler/observer to inspect and copy the vessel's log, communications log, and records... must: (1) Notify the sea sampler/observer of any sea turtles, marine mammals, or other specimens taken...

Measuring sea surface height with a GNSS-Wave Glider

Science.gov (United States)

Morales Maqueda, Miguel Angel; Penna, Nigel T.; Foden, Peter R.; Martin, Ian; Cipollini, Paolo; Williams, Simon D.; Pugh, Jeff P.

2017-04-01

A GNSS-Wave Glider is a novel technique to measure sea surface height autonomously using the Global Navigation Satellite System (GNSS). It consists of an unmanned surface vehicle manufactured by Liquid Robotics, a Wave Glider, and a geodetic-grade GNSS antenna-receiver system, with the antenna installed on a mast on the vehicle's deck. The Wave Glider uses the differential wave motion through the water column for propulsion, thus guaranteeing an, in principle, indefinite autonomy. Solar energy is collected to power all on-board instrumentation, including the GNSS system. The GNSS-Wave Glider was first tested in Loch Ness in 2013, demonstrating that the technology is capable of mapping geoid heights within the loch with an accuracy of a few centimetres. The trial in Loch Ness did not conclusively confirm the reliability of the technique because, during the tests, the state of the water surface was much more benign than would normally be expect in the open ocean. We now report on a first deployment of a GNSS-Wave Glider in the North Sea. The deployment took place in August 2016 and lasted thirteen days, during which the vehicle covered a distance of about 350 nautical miles in the north western North Sea off Great Britain. During the experiment, the GNSS-Wave Glider experienced sea states between 1 (0-0.1 m wave heights) and 5 (2.5-4 m wave heights). The GNSS-Wave Glider data, recorded at 5 Hz frequency, were analysed using a post-processed kinematic GPS-GLONASS precise point positioning (PPP) approach, which were quality controlled using double difference GPS kinematic processing with respect to onshore reference stations. Filtered with a 900 s moving-average window, the PPP heights reveal geoid patterns in the survey area that are very similar to the EGM2008 geoid model, thus demonstrating the potential use of a GNSS-Wave Glider for marine geoid determination. The residual of subtracting the modelled or measured marine geoid from the PPP signal combines information

Deglacial sea level history of the East Siberian Sea and Chukchi Sea margins

Science.gov (United States)

Cronin, Thomas M.; O'Regan, Matt; Pearce, Christof; Gemery, Laura; Toomey, Michael; Semiletov, Igor; Jakobsson, Martin

2017-09-01

Deglacial (12.8-10.7 ka) sea level history on the East Siberian continental shelf and upper continental slope was reconstructed using new geophysical records and sediment cores taken during Leg 2 of the 2014 SWERUS-C3 expedition. The focus of this study is two cores from Herald Canyon, piston core SWERUS-L2-4-PC1 (4-PC1) and multicore SWERUS-L2-4-MC1 (4-MC1), and a gravity core from an East Siberian Sea transect, SWERUS-L2-20-GC1 (20-GC1). Cores 4-PC1 and 20-GC were taken at 120 and 115 m of modern water depth, respectively, only a few meters above the global last glacial maximum (LGM; ˜ 24 kiloannum or ka) minimum sea level of ˜ 125-130 meters below sea level (m b.s.l.). Using calibrated radiocarbon ages mainly on molluscs for chronology and the ecology of benthic foraminifera and ostracode species to estimate paleodepths, the data reveal a dominance of river-proximal species during the early part of the Younger Dryas event (YD, Greenland Stadial GS-1) followed by a rise in river-intermediate species in the late Younger Dryas or the early Holocene (Preboreal) period. A rapid relative sea level rise beginning at roughly 11.4 to 10.8 ka ( ˜ 400 cm of core depth) is indicated by a sharp faunal change and unconformity or condensed zone of sedimentation. Regional sea level at this time was about 108 m b.s.l. at the 4-PC1 site and 102 m b.s.l. at 20-GC1. Regional sea level near the end of the YD was up to 42-47 m lower than predicted by geophysical models corrected for glacio-isostatic adjustment. This discrepancy could be explained by delayed isostatic adjustment caused by a greater volume and/or geographical extent of glacial-age land ice and/or ice shelves in the western Arctic Ocean and adjacent Siberian land areas.

Situation in the sea area between the North Sea and the Baltic Sea. Situationen i havsomraadet mellan Nordsjoen och Oestersjoen

Energy Technology Data Exchange (ETDEWEB)

Dybern, B.I.; Soederstroem, J.; Thorell, L.

1984-01-01

Due to the special topographical and hydrological features the seas surrounding Sweden are very sensitive to both natural changes and changes caused by man. The sea area between the North Sea and the Baltic Sea has come into focus during the last few decades due to problems with pollution and its impact on the ecosystems and to overfishing of some commer- cially important species. In order to elucidate the present situation from the Swedish viewpoint, the National Board of Fisheries, the National Environment Protection Board and the County Council of the County Goeteborg and Bohyslaen arranged a Symposium on the Situation in the Sea Area between the North Sea and the Baltic Sea in Goeteborg, 14-16 March, 1983. This volume contains lectures given at that Symposium. In most cases there are English summaries and English translations of texts to figures and tables.

Moving Horizon Estimation and Control

DEFF Research Database (Denmark)

Jørgensen, John Bagterp

successful and applied methodology beyond PID-control for control of industrial processes. The main contribution of this thesis is introduction and definition of the extended linear quadratic optimal control problem for solution of numerical problems arising in moving horizon estimation and control...... problems. Chapter 1 motivates moving horizon estimation and control as a paradigm for control of industrial processes. It introduces the extended linear quadratic control problem and discusses its central role in moving horizon estimation and control. Introduction, application and efficient solution....... It provides an algorithm for computation of the maximal output admissible set for linear model predictive control. Appendix D provides results concerning linear regression. Appendix E discuss prediction error methods for identification of linear models tailored for model predictive control....

Atmospheric studies with SODAR at Kalpakkam

International Nuclear Information System (INIS)

Somayaji, K.M.

1991-01-01

A doppler SODAR for measurement of wind characteristics at different heights has been installed at HASL, IGCAR, Kalpakkam and is in operation since January 1990. The technical specifications and the basic aspects of SODAR, siting considerations and installation details are given. The report also discusses some observations regarding the site selection, installation and operation of SODARs. The basic theory of SODARs, some aspects of turbulence and dispersion in atmosphere and the various stability classification schemes are outlined. Some details regarding land/sea-breeze circulations and inversions are also given. (author). 6 refs., 10 figs., 8 annextures

Where is the ideal location for a US East Coast offshore grid?

DEFF Research Database (Denmark)

Dvorak, Michael J.; Stoutenburg, Eric D.; Jacobson, Mark Z.

2012-01-01

to the Mid-Atlantic, and (4) have a smoothed power output, reduced hourly ramp rates and hours of zero power. Hourly, high-resolution mesoscale weather model data from 2006-2010 were used to approximate wind farm output. The offshore grid was located in the waters from Long Island, New York to the Georges...... Bank, ≈450 km east. Twelve candidate 500 MW wind farms were located randomly throughout that region. Four wind farms (2000 MW total capacity) were selected for their synergistic meteorological characteristics that reduced offshore grid variability. Sites likely to have sea breezes helped increase...

Effects on atmospheric diffusion of meterological processes in coastal zones

International Nuclear Information System (INIS)

Raynor, G.S.

1977-01-01

Meteorological processes in coastal zones differ from those inland because of the surface discontinuity between land and water. The difference in heating between the two surfaces gives rise to sea or lake breeze circulations which can transport pollutants in nongradient directions and recirculate them over source areas. The step change in surface characteristics at the land-water interface also causes formation of internal boundary layers having different transport velocities and diffusion rates than unmodified air upwind or above the boundary. These features require a more extensive measurement program and more versatile diffusion models than at inland sites

Neuro-fuzzy and neural network techniques for forecasting sea level in Darwin Harbor, Australia

Science.gov (United States)

Karimi, Sepideh; Kisi, Ozgur; Shiri, Jalal; Makarynskyy, Oleg

2013-03-01

Accurate predictions of sea level with different forecast horizons are important for coastal and ocean engineering applications, as well as in land drainage and reclamation studies. The methodology of tidal harmonic analysis, which is generally used for obtaining a mathematical description of the tides, is data demanding requiring processing of tidal observation collected over several years. In the present study, hourly sea levels for Darwin Harbor, Australia were predicted using two different, data driven techniques, adaptive neuro-fuzzy inference system (ANFIS) and artificial neural network (ANN). Multi linear regression (MLR) technique was used for selecting the optimal input combinations (lag times) of hourly sea level. The input combination comprises current sea level as well as five previous level values found to be optimal. For the ANFIS models, five different membership functions namely triangular, trapezoidal, generalized bell, Gaussian and two Gaussian membership function were tested and employed for predicting sea level for the next 1 h, 24 h, 48 h and 72 h. The used ANN models were trained using three different algorithms, namely, Levenberg-Marquardt, conjugate gradient and gradient descent. Predictions of optimal ANFIS and ANN models were compared with those of the optimal auto-regressive moving average (ARMA) models. The coefficient of determination, root mean square error and variance account statistics were used as comparison criteria. The obtained results indicated that triangular membership function was optimal for predictions with the ANFIS models while adaptive learning rate and Levenberg-Marquardt were most suitable for training the ANN models. Consequently, ANFIS and ANN models gave similar forecasts and performed better than the developed for the same purpose ARMA models for all the prediction intervals.

An ML-Based Radial Velocity Estimation Algorithm for Moving Targets in Spaceborne High-Resolution and Wide-Swath SAR Systems

Directory of Open Access Journals (Sweden)

Tingting Jin

2017-04-01

Full Text Available Multichannel synthetic aperture radar (SAR is a significant breakthrough to the inherent limitation between high-resolution and wide-swath (HRWS compared with conventional SAR. Moving target indication (MTI is an important application of spaceborne HRWS SAR systems. In contrast to previous studies of SAR MTI, the HRWS SAR mainly faces the problem of under-sampled data of each channel, causing single-channel imaging and processing to be infeasible. In this study, the estimation of velocity is equivalent to the estimation of the cone angle according to their relationship. The maximum likelihood (ML based algorithm is proposed to estimate the radial velocity in the existence of Doppler ambiguities. After that, the signal reconstruction and compensation for the phase offset caused by radial velocity are processed for a moving target. Finally, the traditional imaging algorithm is applied to obtain a focused moving target image. Experiments are conducted to evaluate the accuracy and effectiveness of the estimator under different signal-to-noise ratios (SNR. Furthermore, the performance is analyzed with respect to the motion ship that experiences interference due to different distributions of sea clutter. The results verify that the proposed algorithm is accurate and efficient with low computational complexity. This paper aims at providing a solution to the velocity estimation problem in the future HRWS SAR systems with multiple receive channels.

Moving carbonation fronts in concrete: a moving-sharp-interface approach

NARCIS (Netherlands)

Muntean, A.; Böhm, M.; Kropp, J.

2011-01-01

We present a new modeling strategy for predicting the penetration of carbonation reaction fronts in concrete. The approach relies on the assumption that carbonation reaction concentrates macroscopically on an a priori unknown narrow strip (called reaction front) moving into concrete gradually

Atmospheric Dispersion Simulation for Level 3 PSA at Ulchin Nuclear Site using a PUFF model

Energy Technology Data Exchange (ETDEWEB)

Lee, Seung Jun; Han, Seok-Jung; Jeong, Hyojoon; Jang, Seung-Cheol [KAERI, Daejeon (Korea, Republic of)

2015-05-15

Air dispersion prediction is a key in the level 3 PSA to predict radiation releases into the environment for preparing an effective strategy for an evacuation as a basis of the emergency preparedness. To predict the atmospheric dispersion accurately, the specific conditions of the radiation release location should be considered. There are various level 3 PSA tools and MACSS2 is one of the widely used level 3 PSA tools in many countries including Korea. Due to the characteristics of environmental conditions in Korea, it should be demonstrated that environmental conditions of Korea nuclear sites can be appropriately illustrated by the tool. In Korea, because all nuclear power plants are located on coasts, sea and land breezes might be a significant factor. The objectives of this work is to simulate the atmospheric dispersion for Ulchin nuclear site in Korea using a PUFF model and to generate the data which can be used for the comparison with that of PLUME model. A nuclear site has own atmospheric dispersion characteristics. Especially in Korea, nuclear sites are located at coasts and it is expected that see and land breeze effects are relatively high. In this work, the atmospheric dispersion at Ulchin nuclear site was simulated to evaluate the effect of see and land breezes in four seasons. In the simulation results, it was observed that the wind direction change with time has a large effect on atmospheric dispersion. If the result of a PLUME model is more conservative than most severe case of a PUFF model, then the PLUME model could be used for Korea nuclear sites in terms of safety assessment.

Sea-ice cover in the Nordic Seas and the sensitivity to Atlantic water temperatures

Science.gov (United States)

Jensen, Mari F.; Nisancioglu, Kerim H.; Spall, Michael A.

2017-04-01

Changes in the sea-ice cover of the Nordic Seas have been proposed to play a key role for the dramatic temperature excursions associated with the Dansgaard-Oeschger events during the last glacial. However, with its proximity to the warm Atlantic water, how a sea-ice cover can persist in the Nordic Seas is not well understood. In this study, we apply an eddy-resolving configuration of the Massachusetts Institute of Technology general circulation model with an idealized topography to study the presence of sea ice in a Nordic Seas-like domain. We assume an infinite amount of warm Atlantic water present in the south by restoring the southern area to constant temperatures. The sea-surface temperatures are restored toward cold, atmospheric temperatures, and as a result, sea ice is present in the interior of the domain. However, the sea-ice cover in the margins of the Nordic Seas, an area with a warm, cyclonic boundary current, is sensitive to the amount of heat entering the domain, i.e., the restoring temperature in the south. When the temperature of the warm, cyclonic boundary current is high, the margins are free of sea ice and heat is released to the atmosphere. We show that with a small reduction in the temperature of the incoming Atlantic water, the Nordic Seas-like domain is fully covered in sea ice. Warm water is still entering the Nordic Seas, however, this happens at depths below a cold, fresh surface layer produced by melted sea ice. Consequently, the heat release to the atmosphere is reduced along with the eddy heat fluxes. Results suggest a threshold value in the amount of heat entering the Nordic Seas before the sea-ice cover disappears in the margins. We study the sensitivity of this threshold to changes in atmospheric temperatures and vertical diffusivity.

Saltmarsh boundary modulates dispersal of mangrove propagules: implications for mangrove migration with sea-level rise.

Science.gov (United States)

Peterson, Jennifer M; Bell, Susan S

2015-01-01

Few studies have empirically examined the suite of mechanisms that underlie the distributional shifts displayed by organisms in response to changing climatic condition. Mangrove forests are expected to move inland as sea-level rises, encroaching on saltmarsh plants inhabiting higher elevations. Mangrove propagules are transported by tidal waters and propagule dispersal is likely modified upon encountering the mangrove-saltmarsh ecotone, the implications of which are poorly known. Here, using an experimental approach, we record landward and seaward dispersal and subsequent establishment of mangrove propagules that encounter biotic boundaries composed of two types of saltmarsh taxa: succulents and grasses. Our findings revealed that propagules emplaced within saltmarsh vegetation immediately landward of the extant mangrove fringe boundary frequently dispersed in the seaward direction. However, propagules moved seaward less frequently and over shorter distances upon encountering boundaries composed of saltmarsh grasses versus succulents. We uniquely confirmed that the small subset of propagules dispersing landward displayed proportionately higher establishment success than those transported seaward. Although impacts of ecotones on plant dispersal have rarely been investigated in situ, our experimental results indicate that the interplay between tidal transport and physical attributes of saltmarsh vegetation influence boundary permeability to propagules, thereby directing the initial phase of shifting mangrove distributions. The incorporation of tidal inundation information and detailed data on landscape features, such as the structure of saltmarsh vegetation at mangrove boundaries, should improve the accuracy of models that are being developed to forecast mangrove distributional shifts in response to sea-level rise.

Moving to a Modernized Height Reference System in Canada: Rationale, Status and Plans

Science.gov (United States)

Veronneau, M.; Huang, J.

2007-05-01

A modern society depends on a common coordinate reference system through which geospatial information can be interrelated and exploited reliably. For height measurements this requires the ability to measure mean sea level elevations easily, accurately, and at the lowest possible cost. The current national reference system for elevations, the Canadian Geodetic Vertical Datum of 1928 (CGVD28), offers only partial geographic coverage of the Canadian territory and is affected by inaccuracies that are becoming more apparent as users move to space- based technologies such as GPS. Furthermore, the maintenance and expansion of the national vertical network using spirit-levelling, a costly, time consuming and labour intensive proposition, has only been minimally funded over the past decade. It is now generally accepted that the most sustainable alternative for the realization of a national vertical datum is a gravimetric geoid model. This approach defines the datum in relation to an ellipsoid, making it compatible with space-based technologies for positioning. While simplifying access to heights above mean sea level all across the Canadian territory, this approach imposes additional demands on the quality of the geoid model. These are being met by recent and upcoming space gravimetry missions that have and will be measuring the Earth`s gravity field with increasing and unprecedented accuracy. To maintain compatibility with the CGVD28 datum materialized at benchmarks, the current first-order levelling can be readjusted by constraining geoid heights at selected stations of the Canadian Base Network. The new reference would change CGVD28 heights of benchmarks by up to 1 m across Canada. However, local height differences between benchmarks would maintain a relative precision of a few cm or better. CGVD28 will co-exist with the new height reference as long as it will be required, but it will undoubtedly disappear as benchmarks are destroyed over time. The adoption of GNSS

Variability and Trends in Sea Ice Extent and Ice Production in the Ross Sea

Science.gov (United States)

Comiso, Josefino; Kwok, Ronald; Martin, Seelye; Gordon, Arnold L.

2011-01-01

Salt release during sea ice formation in the Ross Sea coastal regions is regarded as a primary forcing for the regional generation of Antarctic Bottom Water. Passive microwave data from November 1978 through 2008 are used to examine the detailed seasonal and interannual characteristics of the sea ice cover of the Ross Sea and the adjacent Bellingshausen and Amundsen seas. For this period the sea ice extent in the Ross Sea shows the greatest increase of all the Antarctic seas. Variability in the ice cover in these regions is linked to changes in the Southern Annular Mode and secondarily to the Antarctic Circumpolar Wave. Over the Ross Sea shelf, analysis of sea ice drift data from 1992 to 2008 yields a positive rate of increase in the net ice export of about 30,000 sq km/yr. For a characteristic ice thickness of 0.6 m, this yields a volume transport of about 20 cu km/yr, which is almost identical, within error bars, to our estimate of the trend in ice production. The increase in brine rejection in the Ross Shelf Polynya associated with the estimated increase with the ice production, however, is not consistent with the reported Ross Sea salinity decrease. The locally generated sea ice enhancement of Ross Sea salinity may be offset by an increase of relatively low salinity of the water advected into the region from the Amundsen Sea, a consequence of increased precipitation and regional glacial ice melt.

Temporal and spatial variations of oceanic pCO2 and air-sea CO2 flux in th Greenland Sea and the Barents Sea

International Nuclear Information System (INIS)

Nakaoka, Shin-Ichiro; Aoki, Shuji; Nakazawa, Takakiyo; Yoshikawa-Inoue, Hisayuki

2006-01-01

In order to elucidate the seasonal and inter annual variations of oceanic CO 2 uptake in the Greenland Sea and the Barents Sea, the partial pressure of CO 2 in the surface ocean (pCO 2 sea ) was measured in all seasons between 1992 and 2001. We derived monthly varying relationships between pCO 2 sea and sea surface temperature (SST) and combined them with the SST data from the NCEP/NCAR reanalysis to determine pCO 2 sea and air-sea CO 2 flux in these seas. The pCO 2 sea values were normalized to the year 1995 by assuming that pCO 2 sea increased at the same growth rate (1.5 μatm/yr) of the pCO 2 in the air (pCO 2 air ) between 1992 and 2001. In 1995, the annual net air-sea CO 2 fluxes were evaluated to be 52 ± 20 gC/m 2 /yr in the Greenland Sea and 46 ± 18 gC/m 2 /yr in the Barents Sea. The CO 2 flux into the ocean reached its maximum in winter and minimum in summer. The wind speed and (delta)pCO 2 (=pCO 2 air -pCO 2 sea ) exerted a greater influence on the seasonal variation than the sea ice coverage. The annual CO 2 uptake examined in this study (70-80 deg N, 20 deg W-40 deg E) was estimated to be 0.050 ± 0.020 GtC/yr in 1995. The inter annual variation in the annual CO 2 uptake was found to be positively correlated with the North Atlantic Oscillation Index (NAOI) via wind strength but negatively correlated with (delta)pCO 2 and the sea ice coverage. The present results indicate that the variability in wind speed and sea ice coverage play a major role, while that in (delta)pCO 2 plays a minor role, in determining the interannual variation of CO 2 uptake in this area

Spatio-Temporal Queries for moving objects Data warehousing

OpenAIRE

Esheiba, Leila; Mokhtar, Hoda M. O.; El-Sharkawi, Mohamed

2013-01-01

In the last decade, Moving Object Databases (MODs) have attracted a lot of attention from researchers. Several research works were conducted to extend traditional database techniques to accommodate the new requirements imposed by the continuous change in location information of moving objects. Managing, querying, storing, and mining moving objects were the key research directions. This extensive interest in moving objects is a natural consequence of the recent ubiquitous location-aware device...

First biological measurements of deep-sea corals from the Red Sea

OpenAIRE

C. Roder; M. L. Berumen; J. Bouwmeester; E. Papathanassiou; A. Al-Suwailem; C. R. Voolstra

2013-01-01

It is usually assumed that metabolic constraints restrict deep-sea corals to cold-water habitats, with ?deep-sea? and ?cold-water? corals often used as synonymous. Here we report on the first measurements of biological characters of deep-sea corals from the central Red Sea, where they occur at temperatures exceeding 20?C in highly oligotrophic and oxygen-limited waters. Low respiration rates, low calcification rates, and minimized tissue cover indicate that a reduced metabolism is one of the ...

Assessment of ground transportation stress in juvenile Kemp's ridley sea turtles (Lepidochelys kempii).

Science.gov (United States)

Hunt, Kathleen E; Innis, Charles J; Kennedy, Adam E; McNally, Kerry L; Davis, Deborah G; Burgess, Elizabeth A; Merigo, Constance

2016-01-01

Sea turtle rehabilitation centres frequently transport sea turtles for long distances to move animals between centres or to release them at beaches, yet there is little information on the possible effects of transportation-related stress ('transport stress') on sea turtles. To assess whether transport stress is a clinically relevant concern for endangered Kemp's ridley sea turtles (Lepidochelys kempii), we obtained pre-transport and post-transport plasma samples from 26 juvenile Kemp's ridley sea turtles that were transported for 13 h (n = 15 turtles) or 26 h (n = 11 turtles) by truck for release at beaches. To control for effects of handling, food restriction and time of day, the same turtles were also studied on 'control days' 2 weeks prior to transport, i.e. with two samples taken to mimic pre-transport and post-transport timing, but without transportation. Blood samples were analysed for nine clinical health measures (pH, pCO2, pO2, HCO3, sodium, potassium, ionized calcium, lactate and haematocrit) and four 'stress-associated' parameters (corticosterone, glucose, white blood cell count and heterophil-to-lymphocyte ratio). Vital signs (heart rate, respiratory rate and cloacal temperature) were also monitored. Corticosterone and glucose showed pronounced elevations due specifically to transportation; for corticosterone, this elevation was significant only for the longer transport duration, whereas glucose increased significantly after both transport durations. However, clinical health measures and vital signs showed minimal or no changes in response to any sampling event (with or without transport), and all turtles appeared to be in good clinical health after both transport durations. Thus, transportation elicits a mild, but detectable, adrenal stress response that is more pronounced during longer durations of transport; nonetheless, Kemp's ridley sea turtles can tolerate ground transportation of up to 26 h in good health. These results are likely

Sea Urchin Embryogenesis as Bioindicators of Marine Pollution in Impact Areas of the Sea of Japan/East Sea and the Sea of Okhotsk.

Science.gov (United States)

Lukyanova, Olga N; Zhuravel, Elena V; Chulchekov, Denis N; Mazur, Andrey A

2017-08-01

The embryogenesis of the sea urchin sand dollar Scaphechinus mirabilis was used as bioindicators of seawater quality from the impact areas of the Sea of Japan/East Sea (Peter the Great Bay) and the Sea of Okhotsk (northwestern shelf of Sakhalin Island and western shelf of Kamchatka Peninsula). Fertilization membrane formation, first cleavage, blastula formation, gastrulation, and 2-armed and 4-armed pluteus formation have been analyzed and a number of abnormalities were calculated. Number of embryogenesis anomalies in sand dollar larvae exposed to sea water from different stations in Peter the Great Bay corresponds to pollution level at each area. The Sea of Okhotsk is the main fishing area for Russia. Anthropogenic impact on the marine ecosystem is caused by fishing and transport vessels mainly. But two shelf areas are considered as "hot spots" due to oil and gas drilling. Offshore oil exploitation on the northeastern Sakhalin Island has been started and at present time oil is being drill on oil-extracting platforms continuously. Significant reserves of hydrocarbons are prospected on western Kamchatka shelf, and exploitation drilling in this area was intensified in 2014. A higher number of abnormalities at gastrula and pluteus stages (19-36%) were detected for the stations around oil platforms near Sakhalin Island. On the western Kamchatka shelf number of abnormalities was 7-21%. Such anomalies as exogastrula, incomplete development of pairs of arms were not observed at all; only the delay of development was registered. Eggs, embryos, and larvae of sea urchins are the suitable bioindicators of early disturbances caused by marine pollution in impact ecosystems.

Sea ice algal biomass and physiology in the Amundsen Sea, Antarctica

Directory of Open Access Journals (Sweden)

Kevin R. Arrigo

2014-07-01

Full Text Available Abstract Sea ice covers approximately 5% of the ocean surface and is one of the most extensive ecosystems on the planet. The microbial communities that live in sea ice represent an important food source for numerous organisms at a time of year when phytoplankton in the water column are scarce. Here we describe the distributions and physiology of sea ice microalgae in the poorly studied Amundsen Sea sector of the Southern Ocean. Microalgal biomass was relatively high in sea ice in the Amundsen Sea, due primarily to well developed surface communities that would have been replenished with nutrients during seawater flooding of the surface as a result of heavy snow accumulation. Elevated biomass was also occasionally observed in slush, interior, and bottom ice microhabitats throughout the region. Sea ice microalgal photophysiology appeared to be controlled by the availability of both light and nutrients. Surface communities used an active xanthophyll cycle and effective pigment sunscreens to protect themselves from harmful ultraviolet and visible radiation. Acclimation to low light microhabitats in sea ice was facilitated by enhanced pigment content per cell, greater photosynthetic accessory pigments, and increased photosynthetic efficiency. Photoacclimation was especially effective in the bottom ice community, where ready access to nutrients would have allowed ice microalgae to synthesize a more efficient photosynthetic apparatus. Surprisingly, the pigment-detected prymnesiophyte Phaeocystis antarctica was an important component of surface communities (slush and surface ponds where its acclimation to high light may precondition it to seed phytoplankton blooms after the sea ice melts in spring.

Numerical simulations of local circulations and pollution transport over Reunion Island

Directory of Open Access Journals (Sweden)

D. Lesouëf

2011-01-01

Full Text Available A series of high-resolution (1 km numerical simulations with a limited-area numerical model has been performed over Reunion Island. In the dynamical context of a regular maritime flow perturbed by a major topographic obstacle such as Reunion Island, the objectives are to identify the main atmospheric circulations at local-scale over the island and to improve the understanding of local-scale transport and dispersion of pollutants emitted from local sources. To investigate the effects of topography and land surface heating on low-level flows over the island, simulations representative of austral winter were performed in idealized conditions keeping the radiative forcing plus a background east-south-easterly synoptic flux of varying strengths, typical of the prevailing trade-wind conditions. The numerical experiments show mainly that flow splitting of the trade-wind occurs around the island, with enhanced winds blowing along the coast lines parallel to the synoptic flux, due to the lateral constriction of the flow by the island and resulting Venturi effect. Blocking occurs on the island side facing the trade-wind. The north-western area on the leeside is screened from the trade-wind by high mountains, and this enables the development of diurnal thermally-induced circulations, combining downslope and land-breeze at night, and upslope and sea breeze at daytime. Flow splitting is modulated by radiative convergence toward the island at daytime, and divergence from the island at night. Stronger winds than the large-scale trade-wind occur along the coast at daytime (Venturi effect, whereas at night, the trade-wind flow is pushed few kilometres offshore by divergence of cooled air from the land. At night, the trade-wind flow is pushed few kilometres offshore by divergence of cooled air from the land. Consequently, a number of processes of pollution transport and dispersion have been identified. Vortices in the wake of the island were found to cause

Numerical simulations of local circulations and pollution transport over Reunion Island

Energy Technology Data Exchange (ETDEWEB)

Lesouef, D.; Delmas, R. [La Reunion Univ., CNRS/INSU UMR8105 (France). Lab. de l' Atmosphere et des Cyclones; Gheusi, F.; Escobar, J. [Toulouse III Univ., CNRS/INSU UMR5560 (France). Lab. d' Aerologie

2011-07-01

A series of high-resolution (1 km) numerical simulations with a limited-area numerical model has been performed over Reunion Island. In the dynamical context of a regular maritime flow perturbed by a major topographic obstacle such as Reunion Island, the objectives are to identify the main atmospheric circulations at local-scale over the island and to improve the understanding of local-scale transport and dispersion of pollutants emitted from local sources. To investigate the effects of topography and land surface heating on low-level flows over the island, simulations representative of austral winter were performed in idealized conditions keeping the radiative forcing plus a background east-south-easterly synoptic flux of varying strengths, typical of the prevailing trade-wind conditions. The numerical experiments show mainly that flow splitting of the trade-wind occurs around the island, with enhanced winds blowing along the coast lines parallel to the synoptic flux, due to the lateral constriction of the flow by the island and resulting Venturi effect. Blocking occurs on the island side facing the trade-wind. The north-western area on the leeside is screened from the trade-wind by high mountains, and this enables the development of diurnal thermally-induced circulations, combining downslope and land-breeze at night, and upslope and sea breeze at daytime. Flow splitting is modulated by radiative convergence toward the island at daytime, and divergence from the island at night. Stronger winds than the large-scale trade-wind occur along the coast at daytime (Venturi effect), whereas at night, the trade-wind flow is pushed few kilometres offshore by divergence of cooled air from the land. At night, the trade-wind flow is pushed few kilometres offshore by divergence of cooled air from the land. Consequently, a number of processes of pollution transport and dispersion have been identified. Vortices in the wake of the island were found to cause counterflow circulation

Walrus areas of use in the Chukchi Sea during sparse sea ice cover

Science.gov (United States)

Jay, Chadwick V.; Fischbach, Anthony S.; Kochnev, Anatoly A.

2012-01-01

The Pacific walrus Odobenus rosmarus divergens feeds on benthic invertebrates on the continental shelf of the Chukchi and Bering Seas and rests on sea ice between foraging trips. With climate warming, ice-free periods in the Chukchi Sea have increased and are projected to increase further in frequency and duration. We radio-tracked walruses to estimate areas of walrus foraging and occupancy in the Chukchi Sea from June to November of 2008 to 2011, years when sea ice was sparse over the continental shelf in comparison to historical records. The earlier and more extensive sea ice retreat in June to September, and delayed freeze-up of sea ice in October to November, created conditions for walruses to arrive earlier and stay later in the Chukchi Sea than in the past. The lack of sea ice over the continental shelf from September to October caused walruses to forage in nearshore areas instead of offshore areas as in the past. Walruses did not frequent the deep waters of the Arctic Basin when sea ice retreated off the shelf. Walruses foraged in most areas they occupied, and areas of concentrated foraging generally corresponded to regions of high benthic biomass, such as in the northeastern (Hanna Shoal) and southwestern Chukchi Sea. A notable exception was the occurrence of concentrated foraging in a nearshore area of northwestern Alaska that is apparently depauperate in walrus prey. With increasing sea ice loss, it is likely that walruses will increase their use of coastal haul-outs and nearshore foraging areas, with consequences to the population that are yet to be understood.

Energy flux correlations and moving mirrors

International Nuclear Information System (INIS)

Ford, L.H.; Roman, Thomas A.

2004-01-01

We study the quantum stress tensor correlation function for a massless scalar field in a flat two-dimensional spacetime containing a moving mirror. We construct the correlation functions for right-moving and left-moving fluxes for an arbitrary trajectory, and then specialize them to the case of a mirror trajectory for which the expectation value of the stress tensor describes a pair of delta-function pulses, one of negative energy and one of positive energy. The flux correlation function describes the fluctuations around this mean stress tensor, and reveals subtle changes in the correlations between regions where the mean flux vanishes

Deglacial sea level history of the East Siberian Sea and Chukchi Sea margins

Science.gov (United States)

Cronin, Thomas M.; O'Regan, Matt; Pearce, Christof; Gemery, Laura; Toomey, Michael; Semiletov, Igor

2017-01-01

Deglacial (12.8–10.7 ka) sea level history on the East Siberian continental shelf and upper continental slope was reconstructed using new geophysical records and sediment cores taken during Leg 2 of the 2014 SWERUS-C3 expedition. The focus of this study is two cores from Herald Canyon, piston core SWERUS-L2-4-PC1 (4-PC1) and multicore SWERUS-L2-4-MC1 (4-MC1), and a gravity core from an East Siberian Sea transect, SWERUS-L2-20-GC1 (20-GC1). Cores 4-PC1 and 20-GC were taken at 120 and 115 m of modern water depth, respectively, only a few meters above the global last glacial maximum (LGM;  ∼  24 kiloannum or ka) minimum sea level of  ∼  125–130 meters below sea level (m b.s.l.). Using calibrated radiocarbon ages mainly on molluscs for chronology and the ecology of benthic foraminifera and ostracode species to estimate paleodepths, the data reveal a dominance of river-proximal species during the early part of the Younger Dryas event (YD, Greenland Stadial GS-1) followed by a rise in river-intermediate species in the late Younger Dryas or the early Holocene (Preboreal) period. A rapid relative sea level rise beginning at roughly 11.4 to 10.8 ka ( ∼  400 cm of core depth) is indicated by a sharp faunal change and unconformity or condensed zone of sedimentation. Regional sea level at this time was about 108 m b.s.l. at the 4-PC1 site and 102 m b.s.l. at 20-GC1. Regional sea level near the end of the YD was up to 42–47 m lower than predicted by geophysical models corrected for glacio-isostatic adjustment. This discrepancy could be explained by delayed isostatic adjustment caused by a greater volume and/or geographical extent of glacial-age land ice and/or ice shelves in the western Arctic Ocean and adjacent Siberian land areas.

Deglacial sea level history of the East Siberian Sea and Chukchi Sea margins

Directory of Open Access Journals (Sweden)

T. M. Cronin

2017-09-01

Full Text Available Deglacial (12.8–10.7 ka sea level history on the East Siberian continental shelf and upper continental slope was reconstructed using new geophysical records and sediment cores taken during Leg 2 of the 2014 SWERUS-C3 expedition. The focus of this study is two cores from Herald Canyon, piston core SWERUS-L2-4-PC1 (4-PC1 and multicore SWERUS-L2-4-MC1 (4-MC1, and a gravity core from an East Siberian Sea transect, SWERUS-L2-20-GC1 (20-GC1. Cores 4-PC1 and 20-GC were taken at 120 and 115 m of modern water depth, respectively, only a few meters above the global last glacial maximum (LGM;  ∼  24 kiloannum or ka minimum sea level of  ∼  125–130 meters below sea level (m b.s.l.. Using calibrated radiocarbon ages mainly on molluscs for chronology and the ecology of benthic foraminifera and ostracode species to estimate paleodepths, the data reveal a dominance of river-proximal species during the early part of the Younger Dryas event (YD, Greenland Stadial GS-1 followed by a rise in river-intermediate species in the late Younger Dryas or the early Holocene (Preboreal period. A rapid relative sea level rise beginning at roughly 11.4 to 10.8 ka ( ∼  400 cm of core depth is indicated by a sharp faunal change and unconformity or condensed zone of sedimentation. Regional sea level at this time was about 108 m b.s.l. at the 4-PC1 site and 102 m b.s.l. at 20-GC1. Regional sea level near the end of the YD was up to 42–47 m lower than predicted by geophysical models corrected for glacio-isostatic adjustment. This discrepancy could be explained by delayed isostatic adjustment caused by a greater volume and/or geographical extent of glacial-age land ice and/or ice shelves in the western Arctic Ocean and adjacent Siberian land areas.

Sensitivity of modeled atmospheric nitrogen species and nitrogen deposition to variations in sea salt emissions in the North Sea and Baltic Sea regions

Directory of Open Access Journals (Sweden)

D. Neumann

2016-03-01

Full Text Available Coarse sea salt particles are emitted ubiquitously from the ocean surface by wave-breaking and bubble-bursting processes. These particles impact the atmospheric chemistry by affecting the condensation of gas-phase species and, thus, indirectly the nucleation of new fine particles, particularly in regions with significant air pollution. In this study, atmospheric particle concentrations are modeled for the North Sea and Baltic Sea regions in northwestern Europe using the Community Multiscale Air Quality (CMAQ modeling system and are compared to European Monitoring and Evaluation Programme (EMEP measurement data. The sea salt emission module is extended by a salinity-dependent scaling of the sea salt emissions because the salinity in large parts of the Baltic Sea is very low, which leads to considerably lower sea salt mass emissions compared to other oceanic regions. The resulting improvement in predicted sea salt concentrations is assessed. The contribution of surf zone emissions is considered separately. Additionally, the impacts of sea salt particles on atmospheric nitrate and ammonium concentrations and on nitrogen deposition are evaluated. The comparisons with observational data show that sea salt concentrations are commonly overestimated at coastal stations and partly underestimated farther inland. The introduced salinity scaling improves the predicted Baltic Sea sea salt concentrations considerably. The dates of measured peak concentrations are appropriately reproduced by the model. The impact of surf zone emissions is negligible in both seas. Nevertheless, they might be relevant because surf zone emissions were cut at an upper threshold in this study. Deactivating sea salt leads to minor increases in NH3 +  NH4+ and HNO3 +  NO3− and a decrease in NO3− concentrations. However, the overall effect on NH3 +  NH4+ and HNO3 +  NO3− concentrations is smaller than the deviation from the measurements. Nitrogen wet deposition is

The Ross Sea Dipole - temperature, snow accumulation and sea ice variability in the Ross Sea region, Antarctica, over the past 2700 years

Science.gov (United States)

Bertler, Nancy A. N.; Conway, Howard; Dahl-Jensen, Dorthe; Emanuelsson, Daniel B.; Winstrup, Mai; Vallelonga, Paul T.; Lee, James E.; Brook, Ed J.; Severinghaus, Jeffrey P.; Fudge, Taylor J.; Keller, Elizabeth D.; Baisden, W. Troy; Hindmarsh, Richard C. A.; Neff, Peter D.; Blunier, Thomas; Edwards, Ross; Mayewski, Paul A.; Kipfstuhl, Sepp; Buizert, Christo; Canessa, Silvia; Dadic, Ruzica; Kjær, Helle A.; Kurbatov, Andrei; Zhang, Dongqi; Waddington, Edwin D.; Baccolo, Giovanni; Beers, Thomas; Brightley, Hannah J.; Carter, Lionel; Clemens-Sewall, David; Ciobanu, Viorela G.; Delmonte, Barbara; Eling, Lukas; Ellis, Aja; Ganesh, Shruthi; Golledge, Nicholas R.; Haines, Skylar; Handley, Michael; Hawley, Robert L.; Hogan, Chad M.; Johnson, Katelyn M.; Korotkikh, Elena; Lowry, Daniel P.; Mandeno, Darcy; McKay, Robert M.; Menking, James A.; Naish, Timothy R.; Noerling, Caroline; Ollive, Agathe; Orsi, Anaïs; Proemse, Bernadette C.; Pyne, Alexander R.; Pyne, Rebecca L.; Renwick, James; Scherer, Reed P.; Semper, Stefanie; Simonsen, Marius; Sneed, Sharon B.; Steig, Eric J.; Tuohy, Andrea; Ulayottil Venugopal, Abhijith; Valero-Delgado, Fernando; Venkatesh, Janani; Wang, Feitang; Wang, Shimeng; Winski, Dominic A.; Winton, V. Holly L.; Whiteford, Arran; Xiao, Cunde; Yang, Jiao; Zhang, Xin

2018-02-01

High-resolution, well-dated climate archives provide an opportunity to investigate the dynamic interactions of climate patterns relevant for future projections. Here, we present data from a new, annually dated ice core record from the eastern Ross Sea, named the Roosevelt Island Climate Evolution (RICE) ice core. Comparison of this record with climate reanalysis data for the 1979-2012 interval shows that RICE reliably captures temperature and snow precipitation variability in the region. Trends over the past 2700 years in RICE are shown to be distinct from those in West Antarctica and the western Ross Sea captured by other ice cores. For most of this interval, the eastern Ross Sea was warming (or showing isotopic enrichment for other reasons), with increased snow accumulation and perhaps decreased sea ice concentration. However, West Antarctica cooled and the western Ross Sea showed no significant isotope temperature trend. This pattern here is referred to as the Ross Sea Dipole. Notably, during the Little Ice Age, West Antarctica and the western Ross Sea experienced colder than average temperatures, while the eastern Ross Sea underwent a period of warming or increased isotopic enrichment. From the 17th century onwards, this dipole relationship changed. All three regions show current warming, with snow accumulation declining in West Antarctica and the eastern Ross Sea but increasing in the western Ross Sea. We interpret this pattern as reflecting an increase in sea ice in the eastern Ross Sea with perhaps the establishment of a modern Roosevelt Island polynya as a local moisture source for RICE.

Authigenic gypsum in a deep sea core from Southeastern Arabian Sea

Digital Repository Service at National Institute of Oceanography (India)

Guptha, M.V.S.

Authigenic gypsum has been encountered in a deep sea core RC9-157 from the southeastern Arabian Sea at a depth of 4111 m which is a zone of lysocline. The formation of gypsum in the deep sea region is attributed to the prevailing sulphate rich...

Self-similarity of higher-order moving averages

Science.gov (United States)

Arianos, Sergio; Carbone, Anna; Türk, Christian

2011-10-01

In this work, higher-order moving average polynomials are defined by straightforward generalization of the standard moving average. The self-similarity of the polynomials is analyzed for fractional Brownian series and quantified in terms of the Hurst exponent H by using the detrending moving average method. We prove that the exponent H of the fractional Brownian series and of the detrending moving average variance asymptotically agree for the first-order polynomial. Such asymptotic values are compared with the results obtained by the simulations. The higher-order polynomials correspond to trend estimates at shorter time scales as the degree of the polynomial increases. Importantly, the increase of polynomial degree does not require to change the moving average window. Thus trends at different time scales can be obtained on data sets with the same size. These polynomials could be interesting for those applications relying on trend estimates over different time horizons (financial markets) or on filtering at different frequencies (image analysis).

Revealing Holobiont Structure and Function of Three Red Sea Deep-Sea Corals

KAUST Repository

Yum, Lauren

2014-12-01

Deep-sea corals have long been regarded as cold-water coral; however a reevaluation of their habitat limitations has been suggested after the discovery of deep-sea coral in the Red Sea where temperatures exceed 20˚C. To gain further insight into the biology of deep-sea corals at these temperatures, the work in this PhD employed a holotranscriptomic approach, looking at coral animal host and bacterial symbiont gene expression in Dendrophyllia sp., Eguchipsammia fistula, and Rhizotrochus sp. sampled from the deep Red Sea. Bacterial community composition was analyzed via amplicon-based 16S surveys and cultured bacterial strains were subjected to bioprospecting in order to gauge the pharmaceutical potential of coralassociated microbes. Coral host transcriptome data suggest that coral can employ mitochondrial hypometabolism, anaerobic glycolysis, and surface cilia to enhance mass transport rates to manage the low oxygen and highly oligotrophic Red Sea waters. In the microbial community associated with these corals, ribokinases and retron-type reverse transcriptases are abundantly expressed. In its first application to deep-sea coral associated microbial communities, 16S-based next-generation sequencing found that a single operational taxonomic unit can comprise the majority of sequence reads and that a large number of low abundance populations are present, which cannot be visualized with first generation sequencing. Bioactivity testing of selected bacterial isolates was surveyed over 100 cytological parameters with high content screening, covering several major organelles and key proteins involved in a variety of signaling cascades. Some of these cytological profiles were similar to those of several reference pharmacologically active compounds, which suggest that the bacteria isolates produce compounds with similar mechanisms of action as the reference compounds. The sum of this work offers several mechanisms by which Red Sea deep-sea corals cope with environmental

Sea level hazards: Altimetric monitoring of tsunamis and sea level rise

Science.gov (United States)

Hamlington, Benjamin Dillon

Whether on the short timescale of an impending tsunami or the much longer timescale of climate change-driven sea level rise, the threat stemming from rising and inundating ocean waters is a great concern to coastal populations. Timely and accurate observations of potentially dangerous changes in sea level are vital in determining the precautionary steps that need to be taken in order to protect coastal communities. While instruments from the past have provided in situ measurements of sea level at specific locations across the globe, satellites can be used to provide improved spatial and temporal sampling of the ocean in addition to producing more accurate measurements. Since 1993, satellite altimetry has provided accurate measurements of sea surface height (SSH) with near-global coverage. Not only have these measurements led to the first definitive estimates of global mean sea level rise, satellite altimetry observations have also been used to detect tsunami waves in the open ocean where wave amplitudes are relatively small, a vital step in providing early warning to those potentially affected by the impending tsunami. The use of satellite altimetry to monitor two specific sea level hazards is examined in this thesis. The first section will focus on the detection of tsunamis in the open ocean for the purpose of providing early warning to coastal inhabitants. The second section will focus on estimating secular trends using satellite altimetry data with the hope of improving our understanding of future sea level change. Results presented here will show the utility of satellite altimetry for sea level monitoring and will lay the foundation for further advancement in the detection of the two sea level hazards considered.

Sea-level and deep-sea-temperature variability over the past 5.3 million years.

Science.gov (United States)

Rohling, E J; Foster, G L; Grant, K M; Marino, G; Roberts, A P; Tamisiea, M E; Williams, F

2014-04-24

Ice volume (and hence sea level) and deep-sea temperature are key measures of global climate change. Sea level has been documented using several independent methods over the past 0.5 million years (Myr). Older periods, however, lack such independent validation; all existing records are related to deep-sea oxygen isotope (δ(18)O) data that are influenced by processes unrelated to sea level. For deep-sea temperature, only one continuous high-resolution (Mg/Ca-based) record exists, with related sea-level estimates, spanning the past 1.5 Myr. Here we present a novel sea-level reconstruction, with associated estimates of deep-sea temperature, which independently validates the previous 0-1.5 Myr reconstruction and extends it back to 5.3 Myr ago. We find that deep-sea temperature and sea level generally decreased through time, but distinctly out of synchrony, which is remarkable given the importance of ice-albedo feedbacks on the radiative forcing of climate. In particular, we observe a large temporal offset during the onset of Plio-Pleistocene ice ages, between a marked cooling step at 2.73 Myr ago and the first major glaciation at 2.15 Myr ago. Last, we tentatively infer that ice sheets may have grown largest during glacials with more modest reductions in deep-sea temperature.

The effects of freshwater inflow, inlet conveyance and sea level rise on the salinity regime in the Loxahatchee Estuary

International Nuclear Information System (INIS)

Hu, G.

2002-01-01

The upstream migration of salt water into the historic freshwater reaches of the Loxahatchee River is the likely cause of the altered floodplain cypress forest community along the Northwest Fork and some of its tributaries. Mangroves are replacing cypress forest and areas of mixed swamp hardwoods have reacted to different degrees to the saltwater stress. A hydrodynamic/salinity model was developed to study the influence of freshwater input, tidal inlet deepening and sea level rise on the salinity regime in the estuary. Field data analysis and model simulations indicate that the salinity condition in the estuary is sensitive to the amount of freshwater input from the watershed. During dry seasons the salt front advances into areas that were historically freshwater habitats. Historic evidence indicates that the Loxahatchee estuary was periodically closed and opened to the sea. Due to the active long shore sediment transport, the tidal inlet was probably characterized by shifting sandbars through which ran a narrow and unstable channel. Inlet dredging in the past several decades has increased the hydraulic conveyance of the inlet and the tidal influence into the estuary. The sea level record from a site in south Florida indicates that the sea level has been rising at a rate of approximately 2.3-mm per year. The rise of sea level in the past century has probably raised the mean tide level by about 23 centimeters. If the sea level rise continues as predicted, it is foreseeable that the salt front will move further upstream along with the sea level rise. Field data analysis and the preliminary model output led us to believe that the advance of seawater up the estuary is the combined effect of watershed hydrological changes, inlet deepening and sea level rise. (author)

Dancing-drawing fields of presence in SeaUnSea

DEFF Research Database (Denmark)

Ramsgaard Thomsen, Mette

2008-01-01

Dance and architecture have much in common as both are concerned with practices of space. For a dancer, the act of choreography occurs through the unfolding of spaces by means of gesture and embodied movement, whereas for an architect, space is the medium through which form emerges and habitation...... is constructed. For both, the first space of experience is the space of the body. This essay is a writing out of the interstices of these two disciplines as they touch and inform each other in the process and production of SeaUnSea, an interactive dance installation which premiered at Siobhan Davies Studios...... as part of Dance Umbrella in London, October 2006. SeaUnSea is a collaboration between the authors, choreographer Carol Brown and architect Mette Ramsgard Thomsen, working with programmer Chiron Mottram....

Indicators and SEA

DEFF Research Database (Denmark)

Gao, Jingjing; Kørnøv, Lone; Christensen, Per

Abstract: Indicators are widely used in SEA to measure, communicate and monitor impacts from a proposed policy, plan or programme, and can improve the effectiveness for the SEA by simplifying the complexity of both assessment and presentation. Indicators can be seen as part of the implementation...... and if the information requirement for different target groups is not addressed. Indicators are widely used in SEA to measure, communicate and monitor impacts from a proposed policy, plan or programme, and can improve the effectiveness for the SEA by simplifying the complexity of both assessment and presentation...... process helping to understand, communicate and, integrate important environmental issues in planning and decision-making. On the other hand, use of indicators can also limit SEA effectiveness, if the ones chosen are biased or limited, if the aggregation gives incorrect interpretation...

A theory of traffic congestion at moving bottlenecks

Energy Technology Data Exchange (ETDEWEB)

Kerner, Boris S [Daimler AG, GR/PTF, HPC: G021, 71059 Sindelfingen (Germany); Klenov, Sergey L, E-mail: boris.kerner@daimler.co [Department of Physics, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Moscow Region (Russian Federation)

2010-10-22

The physics of traffic congestion occurring at a moving bottleneck on a multi-lane road is revealed based on the numerical analyses of vehicular traffic with a discrete stochastic traffic flow model in the framework of three-phase traffic theory. We find that there is a critical speed of a moving bottleneck at which traffic breakdown, i.e. a first-order phase transition from free flow to synchronized flow, occurs spontaneously at the moving bottleneck, if the flow rate upstream of the bottleneck is great enough. The greater the flow rate, the higher the critical speed of the moving bottleneck. A diagram of congested traffic patterns at the moving bottleneck is found, which shows regions in the flow-rate-moving-bottleneck-speed plane in which congested patterns emerge spontaneously or can be induced through large enough disturbances in an initial free flow. A comparison of features of traffic breakdown and resulting congested patterns at the moving bottleneck with known ones at an on-ramp (and other motionless) bottleneck is made. Nonlinear features of complex interactions and transformations of congested traffic patterns occurring at on- and off-ramp bottlenecks due to the existence of the moving bottleneck are found. The physics of the phenomenon of traffic congestion due to 'elephant racing' on a multi-lane road is revealed.

A theory of traffic congestion at moving bottlenecks

International Nuclear Information System (INIS)

Kerner, Boris S; Klenov, Sergey L

2010-01-01

The physics of traffic congestion occurring at a moving bottleneck on a multi-lane road is revealed based on the numerical analyses of vehicular traffic with a discrete stochastic traffic flow model in the framework of three-phase traffic theory. We find that there is a critical speed of a moving bottleneck at which traffic breakdown, i.e. a first-order phase transition from free flow to synchronized flow, occurs spontaneously at the moving bottleneck, if the flow rate upstream of the bottleneck is great enough. The greater the flow rate, the higher the critical speed of the moving bottleneck. A diagram of congested traffic patterns at the moving bottleneck is found, which shows regions in the flow-rate-moving-bottleneck-speed plane in which congested patterns emerge spontaneously or can be induced through large enough disturbances in an initial free flow. A comparison of features of traffic breakdown and resulting congested patterns at the moving bottleneck with known ones at an on-ramp (and other motionless) bottleneck is made. Nonlinear features of complex interactions and transformations of congested traffic patterns occurring at on- and off-ramp bottlenecks due to the existence of the moving bottleneck are found. The physics of the phenomenon of traffic congestion due to 'elephant racing' on a multi-lane road is revealed.

Heterogeneous CPU-GPU moving targets detection for UAV video

Science.gov (United States)

Li, Maowen; Tang, Linbo; Han, Yuqi; Yu, Chunlei; Zhang, Chao; Fu, Huiquan

2017-07-01

Moving targets detection is gaining popularity in civilian and military applications. On some monitoring platform of motion detection, some low-resolution stationary cameras are replaced by moving HD camera based on UAVs. The pixels of moving targets in the HD Video taken by UAV are always in a minority, and the background of the frame is usually moving because of the motion of UAVs. The high computational cost of the algorithm prevents running it at higher resolutions the pixels of frame. Hence, to solve the problem of moving targets detection based UAVs video, we propose a heterogeneous CPU-GPU moving target detection algorithm for UAV video. More specifically, we use background registration to eliminate the impact of the moving background and frame difference to detect small moving targets. In order to achieve the effect of real-time processing, we design the solution of heterogeneous CPU-GPU framework for our method. The experimental results show that our method can detect the main moving targets from the HD video taken by UAV, and the average process time is 52.16ms per frame which is fast enough to solve the problem.

Brief: Refloating Maureen platform for reuse in waters away from the North Sea

International Nuclear Information System (INIS)

Tilling, G.M.

1996-01-01

The Maureen platform in the U.K. sector of the North Sea is refloatable by virtue of being a steel, gravity-base structure with large oil storage tanks as legs. The fields producing into the Maureen platform will soon be depleted, and plans are to decommission the platform from its present location. The attractive disposal options all involve refloating the platform as a first step. Of these, reuse of the facility is potentially the most attractive. Once afloat, the platform becomes a towable 110,000-tonne vessel available for use in areas of the world away from the North Sea, with location determined by environmental conditions and water depth. The bulk of the weight (92,000 tonnes) is in the jacket structure; topsides weight is 18,000 tonnes. Subject to detailed tow-route and naval-stability calculations, moving the structure long distances appears to be feasible. This paper discusses the refloating and marine stability of the Maureen oil platform as a vessel under tow. Development and maintenance aspects are presented

Formation of mantle "lone plumes" in the global downwelling zone - A multiscale modelling of subduction-controlled plume generation beneath the South China Sea

Science.gov (United States)

Zhang, Nan; Li, Zheng-Xiang

2018-01-01

It has been established that almost all known mantle plumes since the Mesozoic formed above the two lower mantle large low shear velocity provinces (LLSVPs). The Hainan plume is one of the rare exceptions in that instead of rising above the LLSVPs, it is located within the broad global mantle downwelling zone, therefore classified as a "lone plume". Here, we use the Hainan plume example to investigate the feasibility of such lone plumes being generated by subducting slabs in the mantle downwelling zone using 3D geodynamic modelling. Our geodynamic model has a high-resolution regional domain embedded in a relatively low resolution global domain, which is set up in an adaptive-mesh-refined, 3D mantle convection code ASPECT (Advanced Solver for Problems in Earth's ConvecTion). We use a recently published plate motion model to define the top mechanical boundary condition. Our modelling results suggest that cold slabs under the present-day Eurasia, formed from the Mesozoic subduction and closure of the Tethys oceans, have prevented deep mantle hot materials from moving to the South China Sea from regions north or west of the South China Sea. From the east side, the Western Pacific subduction systems started to promote the formation of a lower-mantle thermal-chemical pile in the vicinity of the future South China Sea region since 70 Ma ago. As the top of this lower-mantle thermal-chemical pile rises, it first moved to the west, and finally rested beneath the South China Sea. The presence of a thermochemical layer (possible the D″ layer) in the model helps stabilizing the plume root. Our modelling is the first implementation of multi-scale mesh in the regional model. It has been proved to be an effective way of modelling regional dynamics within a global plate motion and mantle dynamics background.

Using simulations to forecast homeowner response to sea level rise in South Florida: Will they stay or will they go?

Science.gov (United States)

Treuer, G.

2017-12-01

Sea level rise threatens coastal communities around the world, including South Florida which may be the most financially vulnerable region in the world. Proactive investments in sea level rise adaptive flood protections could reduce South Florida's financial vulnerability. However, it is unclear if local governments and homeowners will be willing to make those investments before it is too late. Our research explores this issue by reporting the results of a novel online simulation that accelerates 348 South Florida homeowners thirty-five years into the future so that they can `live' the effects of sea level rise. The results contain a mix of optimism and caution for the prospects of future adaptation. On the positive side over 75% of participants indicated a willingness to support bond issues to pay for adaptation, even as the costs of the measures and effects of sea level rise increased over the years. Likewise, we find little evidence that politically conservative residents who normally have more skeptical views about climate change would be any less inclined to support adaptation, or only look to information sources that downplay the threat. On the negative side, homeowner interest in moving out of the region increases steadily over time as the sea level rises. This is driven by an increase in worry associated with viewing more information within the simulation.

Sea ice contribution to the air-sea CO(2) exchange in the Arctic and Southern Oceans

DEFF Research Database (Denmark)

Rysgaard...[], Søren; Bendtsen, Jørgen; Delille, B.

2011-01-01

Although salt rejection from sea ice is a key process in deep-water formation in ice-covered seas, the concurrent rejection of CO(2) and the subsequent effect on air-sea CO(2) exchange have received little attention. We review the mechanisms by which sea ice directly and indirectly controls the air......-sea CO(2) exchange and use recent measurements of inorganic carbon compounds in bulk sea ice to estimate that oceanic CO(2) uptake during the seasonal cycle of sea-ice growth and decay in ice-covered oceanic regions equals almost half of the net atmospheric CO(2) uptake in ice-free polar seas. This sea......-sea CO(2) exchange during winter, and (3) release of CO(2)-depleted melt water with excess total alkalinity during sea-ice decay and (4) biological CO(2) drawdown during primary production in sea ice and surface oceanic waters....

Zooplankton community structure in the Yellow Sea and East China Sea in autumn

Directory of Open Access Journals (Sweden)

Hongju Chen

2015-12-01

Full Text Available Abstract Study on zooplankton spatial distribution is essential for understanding food web dynamics in marine ecosystems and fishery management. Here we elucidated the composition and distribution of large mesozooplankton on the continental shelf of the Yellow Sea and East China Sea, and explored the zooplankton community structure in these water masses. Sixty vertical hauls (bottom or 200 m in deep water to surface using a ring net (diameter 0.8 m, 505-μm mesh were exploited in November 2007. The biogeographic patterns of zooplankton communities were investigated using multivariate analysis methods; copepod biodiversity was analyzed using univariate indices. Copepods and protozoans were dominate in the communities. Based on the species composition, we divided the study areas into six station groups. Significant differences in zooplankton assemblages were detected between the Yellow Sea and East China Sea. Species richness was higher in East China Sea groups than those in Yellow Sea, whereas taxonomic distinctness was higher in Yellow Sea than in East China Sea. There was a clear relationship between the species composition and water mass group.

Taxonomic research on deep-sea macrofauna in the South China Sea using the Chinese deep-sea submersible Jiaolong.

Science.gov (United States)

Li, Xinzheng

2017-07-01

This paper reviews the taxonomic and biodiversity studies of deep-sea invertebrates in the South China Sea based on the samples collected by the Chinese manned deep-sea submersible Jiaolong. To date, 6 new species have been described, including the sponges Lophophysema eversa, Saccocalyx microhexactin and Semperella jiaolongae as well as the crustaceans Uroptychus jiaolongae, Uroptychus spinulosus and Globospongicola jiaolongi; some newly recorded species from the South China Sea have also been reported. The Bathymodiolus platifrons-Shinkaia crosnieri deep-sea cold seep community has been reported by Li (2015), as has the mitochondrial genome of the glass sponge L. eversa by Zhang et al. (2016). The population structures of two dominant species, the shrimp Shinkaia crosnieri and the mussel Bathymodiolus platifrons, from the cold seep Bathymodiolus platifrons-Shinkaia crosnieri community in the South China Sea and the hydrothermal vents in the Okinawa Trough, were compared using molecular analysis. The systematic position of the shrimp genus Globospongicola was discussed based on 16S rRNA gene sequences. © 2017 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.