scholarly journals Summertime winds and direct cyclonic circulation: observations from Lake Geneva

1996 ◽  
Vol 14 (11) ◽  
pp. 1207-1220 ◽  
Author(s):  
U. Lemmin ◽  
N. D'Adamo
Keyword(s):  
Cyclonic Circulation ◽  
Land Breeze ◽  
Lake Geneva ◽  
Spectral Peaks ◽  
Modifying Effect ◽  
Strong Winds ◽  
Diurnal Wind ◽  
Mean Circulation ◽  
Variable Wind ◽  
Land Breezes

Abstract. Records of wind, air temperature and air pressure from nine stations, situated along the shoreline of Lake Geneva, Switzerland, were analyzed for the summer period May to September. At all stations the consistent appearance of significant spectral peaks and changes in wind direction at the diurnal frequency indicates the importance of lake-land breezes. It is shown that the surrounding topography has a strong modifying effect (temporal and spatial) on the lake-land breeze. Superimposed on this cyclic wind pattern, short episodes of strong winds with long fetch over parts of Lake Geneva are regularly observed. Both of these winds exert a spatially variable wind stress over the lake surface on the same time scale. Typical examples of the expected lake's response are presented, among them the seasonally persistent gyre in the central part of the lake. Evidence is provided that this dominant circulation is part of a direct cyclonic circulation, generated by the curl of the diurnal wind field. It is concluded that the mean circulation is caused by these winds and affected by the topography of the surrounding land.

scholarly journals Resonant Diurnal Oscillations and Mean Alongshore Flows Driven by Sea/Land Breeze Forcing in the Coastal Southern California Bight

2013 ◽  
Vol 43 (3) ◽  
pp. 616-630 ◽  
Author(s):  
SungHyun Nam ◽  
Uwe Send
Keyword(s):  
Heat Flux ◽  
Southern California ◽  
Southern California Bight ◽  
Land Breeze ◽  
Resonant Response ◽  
Strong Response ◽  
Cross Sectional ◽  
Eddy Heat Flux ◽  
Diurnal Wind ◽  
Land Breezes

Abstract This study presents observations of the cross-sectional structure of resonant response to sea/land breezes (SLBs) off Huntington Beach (HB) in the Southern California Bight (SCB). A resonant response to local diurnal wind stress fluctuations associated with SLB forcing occurs intermittently and produces strong diurnal oscillations of flow and temperature resulting from enhanced work of the diurnal local wind on the sea surface. At nighttime (daytime), a coherent cross-sectional circulation with offshore (onshore) currents in the surface layer (upper 15 m) and onshore (offshore) currents in the intermediate layer around 20 m are generated, with a three-layered vertical structure on the outer shelf. The authors find a net cross-shore eddy heat flux (net cooling of nearshore water) during the period of strong response to SLB, that is, a rectified mean heat flux and steeper isotherms resulting from the diurnal SLB fluctuations. The steepened mean isotherms are also found to be in thermal–wind balance with intensified mean equatorward flow, which thus can also be generated by the resonant SLB dynamics. Similar rectified onshore transport of other quantities is expected, relevant for biogeochemical processes. The distribution of maximum diurnal kinetic energy in time and across the shelf supports the concept that subinertial shears create the sufficient condition for resonant response to SLB forcing.

A 7-Yr Climatological Study of Land Breezes over the Florida Spaceport

2005 ◽  
Vol 44 (3) ◽  
pp. 340-356 ◽  
Author(s):  
Jonathan L. Case ◽  
Mark M. Wheeler ◽  
John Manobianco ◽  
Johnny W. Weems ◽  
William P. Roeder
Keyword(s):  
Onset Time ◽  
Sea Breeze ◽  
Land Breeze ◽  
Density Currents ◽  
East Central ◽  
Central Florida ◽  
Onshore Flow ◽  
Kennedy Space ◽  
Horizontal Temperature Gradients ◽  
Land Breezes

Abstract Seven years of wind and temperature data from a high-resolution network of 44 towers at the Kennedy Space Center and Cape Canaveral Air Force Station were used to develop an objective method for identifying land breezes, which are defined as seaward-moving wind shift lines in this study. The favored meteorological conditions for land breezes consisted of surface high pressure in the vicinity of the Florida peninsula, mainly clear skies, and light synoptic onshore flow and/or the occurrence of a sea breeze during the afternoon preceding a land breeze. The land breeze characteristics are examined for two events occurring under different weather regimes—one with light synoptic onshore flow and no daytime sea breeze, and another following a daytime sea breeze under a prevailing offshore flow. Land breezes were found to occur over east-central Florida in all months of the year and had varied onset times and circulation depths. Land breezes were most common in the spring and summer months and least common in the winter. The average onset times were ∼4–5 h after sunset from May to July and ∼6.5–8 h after sunset from October to January. Land breezes typically moved from the west or southwest during the spring and summer, from the northwest in the autumn, and nearly equally from all directions in the winter. Shallow land breezes (<150-m depth) were typically not associated with the afternoon sea breeze and behaved like density currents, exhibiting the largest temperature decreases and latest onset times. Deep land breezes (>150-m depth) were most often preceded by an afternoon sea breeze, had the smallest horizontal temperature gradients, and experienced a mean onset time that is 4 h earlier than that of shallow land breezes.

scholarly journals Lake and Land Breezes at a Mediterranean Artificial Lake: Observations in Alqueva Reservoir, Portugal

Atmosphere ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 535
Author(s):  
Carolina Purificação ◽  
Miguel Potes ◽  
Gonçalo Rodrigues ◽  
Rui Salgado ◽  
Maria João Costa
Keyword(s):  
Thermal Gradient ◽  
Land Breeze ◽  
Lake Breeze ◽  
Floating Platform ◽  
Night Time ◽  
Artificial Lake ◽  
Local Climate ◽  
Main Driver ◽  
Alqueva Reservoir ◽  
Land Breezes

The Alqueva reservoir, in the Southeast of Portugal, has significantly changed the landscape of the region, with impacts also on the local climate, as documented in this manuscript, namely the thermal circulation in the form of lake and land breezes. Taking advantage of three strategic meteorological stations, two installed at the shores and another on a floating platform located near the center of the reservoir, a detailed analysis of lake and land breeze occurrences during two years is presented in this study. The thermal gradient between the reservoir and the surroundings is the main driver for the breeze development and the meteorological stations placed in opposite sides of the reservoir allow to establish the criteria in order to detect lake and land breezes. The results showed more land breeze than lake breeze occurrences, in line with the more negative thermal gradient between shores and reservoir in the annual cycle. Lake breezes are more frequent in summer months during daytime and land breezes in turn are more frequent in winter months during night-time.

Ground Features of Sea Land Breezes in Hainan Island

2015 ◽  
Vol 733 ◽  
pp. 382-386
Author(s):  
Xiao Lan Tang
Keyword(s):  
Temporal Variation ◽  
Seasonal Variations ◽  
Regional Difference ◽  
Surface Wind ◽  
Hainan Island ◽  
Land Breeze ◽  
Land Breezes ◽  
Significant Regional Difference

In this study, based on the observed surface wind in 8 meteorological stations at coastal locations of Hainan Island, the frequency of sea-land breeze (SLB) is studied to depict the characteristics and spatial-temporal variation of the SLB. The statistics indicate that, because of the large variation in coastal terrain and orientation of the island, the number of SLB days and the duration of the SLB at different stations has significant regional difference and seasonal variations.

scholarly journals Rotation of sea/land breezes along the northeastern Adriatic coast

2008 ◽  
Vol 26 (7) ◽  
pp. 1711-1724 ◽  
Author(s):  
M. T. Prtenjak ◽  
Z. Pasarić ◽  
M. Orlić ◽  
B. Grisogono
Keyword(s):  
Mesoscale Model ◽  
Three Dimensional ◽  
Land Breeze ◽  
Clockwise Rotation ◽  
Component Method ◽  
Sensitivity Tests ◽  
Adriatic Coast ◽  
Topographic Forcing ◽  
Land Breezes ◽  
Large Wind

Abstract. The diurnal evolution of the sea/land breeze hodographs over the northeastern Adriatic coast has been examined for several episodes, each lasting a few days. A limited set of observations, as well as the results of a three-dimensional nonhydrostatic mesoscale model are studied by applying a rotary-component method. This revealed a spatial distribution of the clockwise versus anti-clockwise rotation of the wind vectors for the sea/land breeze events. An application of the rotary-component method to the results of additional numerical sensitivity tests showed that the coastal topography height considerably influences both the shape of the wind hodographs and the sense of wind rotation. The method also displayed which areas are under a strong influence of the 24-h topographic forcing and which areas show a large wind consistency. A further analysis of the 24-h modeled wind hodographs at several selected stations has been performed, thus revealing the hodograph shapes and the reasons for them.

scholarly journals Estudo dos Padrões Climatológicos do Vento Usando Transformada em Ondeletas (A Study of the Climatological Patterns of the Wind Using Wavelet Transform)

2014 ◽  
Vol 7 (5) ◽  
pp. 774
Author(s):  
Marcos Antonio Moura ◽  
Rayonil Gomes Carneiro
Keyword(s):  
Wavelet Transform ◽  
Large Scale ◽  
Northeastern Brazil ◽  
Eastern Coast ◽  
Land Breeze ◽  
Trade Winds ◽  
Local Systems ◽  
Hourly Data ◽  
De Se ◽  
Land Breezes

A costa leste do Nordeste Brasileiro (NEB) é palco da ação simultânea de fenômenos transientes que interagem com os sistemas locais, modificando sua frequência e intensidade. Neste trabalho, utiliza-se a técnica de Transformada em Ondeletas (TO) para analisar as séries temporais de magnitude do vento (componente zonal), a fim de aprimorar o entendimento dos sistemas locais de brisas marinhas e terrestres na costa leste de Alagoas. Esta técnica (TO) fornece uma moldura hierárquica que permite a dupla localização em tempo e frequência. Para isso foram utilizados os dados horários médios de velocidade do vento no período de Outubro de 2004 a Outubro de 2005 numa área de proteção ambiental da Ilha de Santa Rita, Marechal Deodoro, Alagoas (9° 42’ 18’’ S e 35° 48’ 32’’ W). As características do sinal mostraram a distinção entre as quadras seca e chuvosa. Na quadra seca, prevalecem os sistemas locais. Na quadra chuvosa predominam os sistemas transientes de grande escala, que inibem os efeitos das brisas. Na mesma base de dados, a direção do vento também foi analisada no intuito de revelar uma direção preferencial e sua persistência. Para este fim, foram utilizados gráficos do tipo rosa-dos-ventos e histogramas de frequências. Verificou-se que as maiores amplitudes e persistência dos ventos são de Sudeste (brisas) e foram incrementadas pelos ventos Alísios de SE, que sopraram o ano inteiro, criando uma interferência construtiva no sinal.  A B S T R A C T The eastern coast of Northeastern Brazil experiments a large number of simultaneous weather related transients that interact with the local systems affecting their frequency and intensity. In this study, the wavelet transform is used to analyze time series of the wind magnitude (zonal components) in order to improve our understanding of the sea/land breeze system in the Alagoas State coastal area, Brazil. This technique provides a hierarchical frame that accommodates double location in time and frequency. Hourly data of averaged winds measured at the Ilha de Santa Rita, an ecological park located in Marechal Deodoro (Alagoas (9° 42’ 18’’ S e 35° 48’ 32’’ W ) during October, 2004 – October, 2005 period were used for the above mentioned objective.  The signals clearly identified the dry and rainy four month periods. The local systems prevailed during the dry periods, contrasting with the rainy periods when the transient large scale systems inhibited the breeze circulation. The wind direction was also analyzed using the same data basis in order to detect any preferential direction and  the associated persistence. It was noticed that the largest amplitudes and persistences were related to the southeastern sea/land breezes enhanced by the year around blowing trade winds.   Key words: Local winds, sea/land breezes and wavelet analyzis.   

Summertime Precipitation Regimes Associated with the Sea Breeze and Land Breeze in Southern Mississippi and Eastern Louisiana

2010 ◽  
Vol 25 (6) ◽  
pp. 1755-1779 ◽  
Author(s):  
Christopher M. Hill ◽  
Patrick J. Fitzpatrick ◽  
James H. Corbin ◽  
Yee H. Lau ◽  
Sachin K. Bhate
Keyword(s):  
Statistical Significance ◽  
Surface Wind ◽  
Late Summer ◽  
Precipitable Water ◽  
Sea Breeze ◽  
Convective Precipitation ◽  
Land Breeze ◽  
Precipitation Regimes ◽  
Diurnal Wind ◽  
Wind Regimes

Abstract This study assesses the monthly climatology of the timing and placement of convective precipitation events induced by sea and land breezes in the Louisiana–Mississippi–Alabama region, and determines possible reasons for the monthly differences. These objectives were achieved through surface wind climatologies and radar composites from 2003 to 2005, supplemented by statistically significant tests. It is shown that June had an easterly–southeasterly wind regime, whereas July and August featured more southerly flow. These wind regimes may have influenced monthly diurnal wind patterns along the coast. While all months showed a typical pattern of sea-breeze evolution, the land breeze demonstrated monthly variations off the Mississippi and Louisiana coasts. July and August feature a westerly land breeze from Louisiana, while the Mississippi land breeze was stronger in August than in July. A daily wind speed minimum offshore from Mississippi indicates a local transition of influence from the land breeze to the sea breeze, and precedes the peak of the sea breeze at the coastline by about 2 h. During the nighttime hours, radar composites show that precipitation is most prevalent offshore of the Louisiana and Mississippi coastline. By 1100 central daylight time (CDT), precipitation is observed over coastal regions. Local afternoon precipitation is widespread throughout the inland areas, while precipitation is minimal offshore. Statistical significance tests show that areal precipitation coverage (APC) increases in mid- to late summer on the Mississippi coast are due to higher precipitable water and, to a lesser extent, additional CAPE. Greater offshore APC in July and August results from the influence of the local land-breeze setup. Convergence of a land breeze from eastern Louisiana and a stronger land breeze from Mississippi provides the additional lift needed to generate convection over a greater area.

Observations on Cardiac Output and ”Pulmonary Blood Volume” in Normal Man by External Recording of the Intracardiac Flow of 131I Labelled Albumin

1961 ◽  
Vol 1 (04) ◽  
pp. 353-379
Author(s):  
Jacques Lammerant ◽  
Norman Veall ◽  
Michel De Visscher
Keyword(s):  
Cardiac Output ◽  
Blood Volume ◽  
Normal Subjects ◽  
Published Data ◽  
Total Blood Volume ◽  
Total Blood ◽  
Pulmonary Blood Volume ◽  
Intracardiac Flow ◽  
Normal Man ◽  
Mean Circulation

Summary1. The technique for the measurement of cardiac output by external recording of the intracardiac flow of 131I labelled human serum albumin has been extended to provide a measure of the mean circulation time from right to left heart and hence a new approach to the estimation of the pulmonary blood volume.2. Values for the basal cardiac output in normal subjects and its variations with age are in good agreement with the previously published data of other workers.3. The pulmonary blood volume in normal man in the basal state was found to be 28.2 ± 0.6% of the total blood volume.4. There was no correlation between cardiac output and pulmonary blood volume in a series of normal subjects in the basal state.5. The increase in cardiac output during digestion was associated with a decrease in pulmonary blood volume equal to 6.3 ± 1.2% of the total blood volume, that is, about 280 ml.6. The increase in cardiac output during exercise was associated with a decrease in pulmonary blood volume equal to 4.5 ± 1.0% of the total blood volume, that is, about 200 ml.7. The increase in cardiac output attributed to alarm is not associated with a decrease in pulmonary blood volume, the latter may in fact be increased.8. The total blood volume is advocated as a standard of reference for studies of this type in normal subjects in preference to body weight or surface area.9. The significance of these results and the validity of the method are discussed.

Teresa Mannion and the Emergence of Extreme Weather Culture in Ireland

2019 ◽  
Vol 49 (1) ◽  
pp. 135-150
Author(s):  
Diane Negra
Keyword(s):  
Climate Change ◽  
At Risk ◽  
Popular Culture ◽  
Extreme Weather ◽  
Cross Cultural ◽  
Viral Video ◽  
Cultural Information ◽  
Strong Winds ◽  
Risk Coverage

In this article I consider how registers of weather media carry/convey cultural information, specifically how texts about extreme weather articulate with investment in a supposed post-recession restored normality marked by the Irish government's commitment to deregulated transnational capitalism. I maintain that, in a process of cross-cultural remediation, sensationalist codes of US weather media that discursively manage awareness of systemic climate problems are just starting to infiltrate the Irish broadcasting environment. In early December 2015 RTÉ’s Teresa Mannion covered a strong gale, Storm Desmond, amidst inclement conditions in Salthill, Co Galway. Modelling the kind of ‘body at risk’ coverage consummately performed by US Weather Channel personnel, Mannion could barely speak over the lashing rain and strong winds in a dramatic broadcast that quickly became a viral video. This article analyses the fascination with Mannion's piece and its memetic, and attends to the nature of the pleasure taken in her on-camera discomfiture and the breach of gendered territory committed by Mannion at a time when national popular culture in Ireland is under increased obligation to identify and explain climate change-related extreme weather.

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