Shade Levels, Wind Speed, and Wind Direction Influence Air Temperature in Mini-shadehouses

The effect of four shade levels (47%, 63%, 80%, and 91%) on air temperature was evaluated using 24 arch-shaped, open-ended shadestructures oriented with their longitudinal axis in north–south direction. The mini-shadehouses were 80 × 185 × 80 cm (width × length × height). Six replicates per treatment (shade level) were randomly assigned within the experimental plot. Light levels were measured using Sunceram solar cells. Copper-Constantan thermocouples were installed 60 cm from ground level and 20 cm from the north entrance. The experiment was initiated in July 1994 and terminated in Oct. 1994. Data from 20 consecutive days in August were analyzed. Eighty percent shade had the highest air temperature; however, the average difference between 47%, 63%, and 91% shade was less than 1C. Wind direction and speed affected air temperature with north or south winds correlated with highest temperatures. Analysis of the data shows averaged air temperatures differed by ≤1C for all shade levels. Consequently, these structures may be used for replicated research studies involving plant growth.

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Heatwaves and Summer Urban Heat Islands: A Daily Cycle Approach to Unveil the Urban Thermal Signal Changes in Lisbon, Portugal

Atmosphere ◽

10.3390/atmos12030292 ◽

2021 ◽

Vol 12 (3) ◽

pp. 292 ◽

Cited By ~ 1

Author(s):

Ana Oliveira ◽

António Lopes ◽

Ezequiel Correia ◽

Samuel Niza ◽

Amílcar Soares

Keyword(s):

Climate Change ◽

Air Temperature ◽

Wind Direction ◽

Urban Heat Islands ◽

Daily Cycle ◽

Local Climate ◽

Thermal Signal ◽

Air Temperatures ◽

Local Climate Change ◽

Urban Heat

Lisbon is a European Mediterranean city, greatly exposed to heatwaves (HW), according to recent trends and climate change prospects. Considering the Atlantic influence, air temperature observations from Lisbon’s mesoscale network are used to investigate the interactions between background weather and the urban thermal signal (UTS) in summer. Days are classified according to the prevailing regional wind direction, and hourly UTS is compared between HW and non-HW conditions. Northern-wind days predominate, revealing greater maximum air temperatures (up to 40 °C) and greater thermal amplitudes (approximately 10 °C), and account for 37 out of 49 HW days; southern-wind days have milder temperatures, and no HWs occur. Results show that the wind direction groups are significantly different. While southern-wind days have minor UTS variations, northern-wind days have a consistent UTS daily cycle: a diurnal urban cooling island (UCI) (often lower than –1.0 °C), a late afternoon peak urban heat island (UHI) (occasionally surpassing 4.0 °C), and a stable nocturnal UHI (1.5 °C median intensity). UHI/UCI intensities are not significantly different between HW and non-HW conditions, although the synoptic influence is noted. Results indicate that, in Lisbon, the UHI intensity does not increase during HW events, although it is significantly affected by wind. As such, local climate change adaptation strategies must be based on scenarios that account for the synergies between potential changes in regional air temperature and wind.

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Atmospheric Circulation Effects on Wind Speed Variability at Turbine Height

Journal of Applied Meteorology and Climatology ◽

10.1175/jam2466.1 ◽

2007 ◽

Vol 46 (4) ◽

pp. 445-456 ◽

Cited By ~ 50

Author(s):

Katherine Klink

Keyword(s):

Wind Speed ◽

Pressure Gradient ◽

Large Scale ◽

Ground Level ◽

The Arctic ◽

Circulation Index ◽

Regression Equations ◽

Change Models ◽

Wind Speeds ◽

The North

Abstract Mean monthly wind speed at 70 m above ground level is investigated for 11 sites in Minnesota for the period 1995–2003. Wind speeds at these sites show significant spatial and temporal coherence, with prolonged periods of above- and below-normal values that can persist for as long as 12 months. Monthly variation in wind speed primarily is determined by the north–south pressure gradient, which captures between 22% and 47% of the variability (depending on the site). Regression on wind speed residuals (pressure gradient effects removed) shows that an additional 6%–15% of the variation can be related to the Arctic Oscillation (AO) and Niño-3.4 sea surface temperature (SST) anomalies. Wind speeds showed little correspondence with variation in the Pacific–North American (PNA) circulation index. The effect of the strong El Niño of 1997/98 on the wind speed time series was investigated by recomputing the regression equations with this period excluded. The north–south pressure gradient remains the primary determinant of mean monthly 70-m wind speeds, but with 1997/98 removed the influence of the AO increases at nearly all stations while the importance of the Niño-3.4 SSTs generally decreases. Relationships with the PNA remain small. These results suggest that long-term patterns of low-frequency wind speed (and thus wind power) variability can be estimated using large-scale circulation features as represented by large-scale climatic datasets and by climate-change models.

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What can idealized storm surge simulations tell us about worst case scenarios?

10.5194/egusphere-egu21-12284 ◽

2021 ◽

Author(s):

Elin Andrée ◽

Jian Su ◽

Martin Drews ◽

Morten Andreas Dahl Larsen ◽

Asger Bendix Hansen ◽

...

Keyword(s):

Wind Speed ◽

Sea Level ◽

North Sea ◽

Wind Direction ◽

Water Levels ◽

Sea Levels ◽

The North ◽

The North Sea ◽

Sea Coast ◽

North Sea Coast

The potential impacts of extreme sea level events are becoming more apparent to the public and policy makers alike. As the magnitude of these events are expected to increase due to climate change, and increased coastal urbanization results in ever increasing stakes in the coastal zones, the need for risk assessments is growing too.The physical conditions that generate extreme sea levels are highly dependent on site specific conditions, such as bathymetry, tidal regime, wind fetch and the shape of the coastline. For a low-lying country like Denmark, which consists of a peninsula and islands that partition off the semi-enclosed Baltic Sea from the North Sea, a better understanding of how the local sea level responds to wind forcing is urgently called for.We here present a map for Denmark that shows the most efficient wind directions for generating extreme sea levels, for a total of 70 locations distributed all over the country&#8217;s coastlines. The maps are produced by conducting simulations with a high resolution, 3D-ocean model, which is used for operational storm surge modelling at the Danish Meteorological Institute. We force the model with idealized wind fields that maintain a fixed wind speed and wind direction over the entire model domain. Simulations are conducted for one wind speed and one wind direction at a time, generating ensembles of a set of wind directions for a fixed wind speed, as well as a set of wind speeds for a fixed wind direction, respectively.For each wind direction, we find that the maximum water level at a given location increases linearly with the wind speed, and the slope values show clear spatial patterns, for example distinguishing the Danish southern North Sea coast from the central or northern North Sea Coast. The slope values are highest along the southwestern North Sea coast, where the passage of North Atlantic low pressure systems over the shallow North Sea, as well as the large tidal range, result in a much larger range of variability than in the more sheltered Inner Danish Waters. However, in our simulations the large fetch of the Baltic Sea, in combination with the funneling effect of the Danish Straits, result in almost as high water levels as along the North Sea coast.Although the wind forcing is completely synthetic with no spatial and temporal structure of a real storm, this idealized approach allows us to systematically investigate the sea level response at the boundaries of what is physically plausible. We evaluate the results from these simulations by comparison to peak water levels from a 58 year long, high resolution ocean hindcast, with promising agreement.

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Assessment of Resource and Forecast Modeling of Wind Speed through An Evolutionary Programming Approach for the North of Tehuantepec Isthmus (Cuauhtemotzin, Mexico)

Energies ◽

10.3390/en11113197 ◽

2018 ◽

Vol 11 (11) ◽

pp. 3197 ◽

Cited By ~ 4

Author(s):

Luis López-Manrique ◽

E. Macias-Melo ◽

O. May Tzuc ◽

A. Bassam ◽

K. Aguilar-Castro ◽

...

Keyword(s):

Wind Speed ◽

Computation Time ◽

Ground Level ◽

Bimodal Distribution ◽

Programming Approach ◽

Climatic Data ◽

Wind Speeds ◽

Availability Analysis ◽

The North ◽

Wind Resource

This work studies the characteristics of the wind resource for a location in the north zone of Tehuantepec isthmus. The study was conducted using climatic data from Cuauhtemotzin, Mexico, measured at different altitudes above the ground level. The measured data allowed establishing the profile of wind speeds as well as the analysis of its availability. Analysis results conclude that the behavior of the wind speed presents a bimodal distribution with dominant northeast wind direction (wind flow of sea–land). In addition, the area was identified as feasible for the use of low speed power wind turbines. On the other hand, the application of a new approach for very short-term wind speed forecast (10 min) applying multi-gene genetic programming and global sensitivity analysis is also presented. Using a computational methodology, an exogenous time series with fast computation time and good accuracy was developed for the forecast of the wind speed. The results presented in this work complement the panorama for the evaluation of the resource in an area recognized worldwide for its vast potential for wind power.

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CORRELATION COMMUNICATION BETWEEN METEOROLOGICAL PARAMETERS AT EXTREME VALUES OF MAXIMUM AIR TEMPERATURES

Hydrology, hydrochemistry and hydroecology ◽

10.17721/2306-5680.2020.1.11 ◽

2020 ◽

pp. 101-112

Author(s):

S.V. Savchuk ◽

V.E. Timofeev ◽

O.A. Shcheglov ◽

V.A. Artemenko ◽

I.L. Kozlenko

Keyword(s):

Air Temperature ◽

Meteorological Parameters ◽

Extreme Values ◽

Daily Temperature ◽

Sea Level Pressure ◽

Maximum Daily Temperature ◽

The North ◽

Air Temperatures ◽

Average Maximum ◽

Maximum Air Temperature

The object of the study is the maximum daily air temperature during the months of the year over 1991-2016 by the data of 186 meteorological stations of Ukraine. Extreme values of the maximum daily temperature equal to or exceeded their 95th (Tmax95p and above, ºС) percentile were taken as extreme. The article sets the dates (137 cases) of extreme values of maximum air temperature on more than 60 % of the territory. For these dates, 13 meteorological parameters were selected: average, minimum, and maximum air temperatures; average, minimum and maximum relative humidity; station and sea-level pressure; average, maximum (from 8 synoptic hours) wind speed; rainfall; height of snow cover. The purpose of this work is to determine the correlation coefficient (K), in particular, statistically significant (K≤-0.6, K≥0.6), on these dates between selected meteorological parameters at 186 meteorological stations of Ukraine for 1991-2013. The density of the cases of statistically significant dependence between the meteorological parameters in extremely warm days in separate seasons is determined. In extremely warm days, meteorological parameters and areas with statistically significant correlations at K≤-0.6 were detected: T and F (focally in southern and some western regions with significant density) − in winter; T and F (with the highest density ubiquitous or almost ubiquitous), P and V (in a large number of regions, usually west or right-bank, but with less frequency) − in the transition seasons, and in the autumn between − T and F (in the south with smaller density) and P and F (in some areas of the north, northwest, west, lower east). In all seasons, such a correlation between other meteorological parameters had a focal distribution, usually with a smaller density. In these days, a focal distribution with a small frequency of dependencies at K≥0.6 was found between the meteorological parameters detected (F and V in transition seasons, T and F in winter), except for similar ones. However, such dependence is observed between T and V in some regions in winter and autumn and in some areas of south, southeast, east with a smaller density. The study of the maximum daily temperature is relevant, because from the level of natural hydrometeorological phenomena it is accompanied by dangerous phenomena, negatively affecting the weather dependent industries.

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Thermal, pressure and wind fields at ground level in the area of the Italian base at Terra Nova Bay, Victoria Land, Antarctica, as observed by a network of automatic weather stations

Annales Geophysicae ◽

10.1007/s00585-996-1088-1 ◽

1996 ◽

Vol 14 (10) ◽

pp. 1088-1094 ◽

Cited By ~ 1

Author(s):

E. Cogliani ◽

G. Abbate ◽

S. Racalbuto

Keyword(s):

Wind Speed ◽

Coastal Region ◽

Ground Level ◽

Katabatic Wind ◽

Wind Fields ◽

The North ◽

Terra Nova Bay ◽

Spatial Configurations ◽

Weather Stations ◽

Terra Nova

Abstract. Ground temperature, pressure and wind speed monthly averages in the area of the Italian Station at Terra Nova Bay, Antarctica, were analyzed for the period 1987–1991 by means of a network of nine AWS (automatic weather stations). Spatial configurations of temperature show a well-defined, relatively warm island in the area of Terra Nova Bay, between Drygalsky and Campbell ice tongues, throughout the year. A second warm island is present to the north along the coast, between Aviator and Mariner ice tongues, for most of the year. From February to March a rapid drop in temperature is observed at all stations. A strong thermal gradient develops during February, March, April and October, November, December, between the coastal region and inner highlands. The baric configuration follows the elevation of the area. Annual average pressure and temperature as functions of stations altitude show linear trends. Severe katabatic wind episodes are recorded at all stations, with wind speed exceeding 25 m s–1 and direction following the orographic features of the inner areas. Co-occurrences of these episodes were observed for stations located along stream lines of cold air drainage. The autocorrelation function of maximum wind speed time series shows wind persistence of 2–3 days and wind periodicity of about one week.

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The Large-eddy Observatory Voitsumra Experiment 2019 (LOVE19) with high-resolution, spatially-distributed observations of air temperature, wind speed, and wind direction from fiber-optic distributed sensing, towers, and ground-based remote sensing

10.5194/essd-2020-392 ◽

2021 ◽

Author(s):

Karl Lapo ◽

Anita Freundorfer ◽

Antonia Fritz ◽

Johann Schneider ◽

Johannes Olesch ◽

...

Keyword(s):

Remote Sensing ◽

Boundary Layer ◽

Wind Speed ◽

Air Temperature ◽

Wind Direction ◽

Fiber Optic ◽

Layer Structure ◽

Distributed Sensing ◽

Near Surface ◽

Large Eddy

Abstract. The weak-wind Stable Boundary Layer (wwSBL) is poorly described by theory and breaks basic assumptions necessary for observations of turbulence. Understanding the wwSBL requires distributed observations capable of separating between submeso and turbulent scales. To this end, we present the Large Eddy Observatory, Voitsumra Experiment 2019 (LOVE19) which featured 1350 m of fiber optic distributed sensing (FODS) of air temperature and wind speed, as well as an experimental wind direction method, at scales as fine as 1 s and 0.127 m in addition to a suite of point observations of turbulence and ground-based remote sensing. Additionally, flights with a fiber optic cable attached to a tethered balloon provide an unprecedented detailed view of the boundary layer structure with a resolution of 0.254 m and 10 s between 1–200 m height. Two examples are provided demonstrating the unique capabilities of the LOVE19 data for examining boundary layer processes: 1) FODS observations between 1m and ~200 m height during a period of gravity waves propagating across the entire boundary layer and 2) tracking a near-surface, transient submeso structure that causes an intermittent burst of turbulence. All data can be accessed at Zenodo through the DOI https://doi.org/10.5281/zenodo.4312976 (Lapo et al., 2020a).

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Evaluating Performance of Utilizing Onshore Wind Turbines Specifically the Farm Turbines in Kuwait

Engineering International ◽

10.18034/ei.v7i1.454 ◽

2019 ◽

Vol 7 (1) ◽

pp. 31-48

Author(s):

Mohammed Salem Alsubai'e ◽

Saad Abdullah Alshatti

Keyword(s):

Renewable Energy ◽

Wind Speed ◽

Wind Turbines ◽

Wind Direction ◽

Onshore Wind ◽

North East ◽

The North ◽

Proportional Relation ◽

Proper Design ◽

The Impact

Renewable energy is considered one of the most important and clean sources; since it does not produce any type of emission or pollution. In Kuwait, the energy of wind is existing in three main locations, which are; Ras Jal Aliyah, Bubian in addition to Subiyah, where the characteristics of wind have been evaluated in this paper based on the data generated from the meteorological measurements at 10m height. Also, different studies have been performed in this paper in order to analyze the impact of height on the parameters of wind energy, wind density, in addition to wind speed. Jal Aliyah location has been studied in this paper and the results showed that there is a proportional relation between the wind speed and power, where the maximum power is potential if the speed is equal to 29.1 m/s, and the maximum averaged flux of wind power is equal to 725.54 W/m2. Where both Bubidan Island and Ras Subiyah showed the wind direction in the North-East quadrant with speed is greater than 10 m/s. But, the higher polarized distribution of Jal Aliyah was in the north direction. Based on the obtained results, it can be concluded that this paper provides and suggests a proper design of the wind turbines for designers.

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Observational Study of Nisarg Cyclone Winds using Phased Array Doppler Sodar at Atigre, Kolhapur, India

10.21203/rs.3.rs-971499/v1 ◽

2021 ◽

Author(s):

Rani P. Pawar ◽

Thiyagesan dharmaraj ◽

Dada P. Nade ◽

Mahendra N. Patil ◽

Omkar M. Patil ◽

...

Keyword(s):

Wind Speed ◽

Wind Direction ◽

Phased Array ◽

Vertical Wind Shear ◽

Longwave Radiation ◽

Western Coast ◽

Sodar Data ◽

The North ◽

Doppler Sodar ◽

Mean Wind Speed

Abstract One of the most important parameters in meteorology is the mean wind profile in the tropical cyclone boundary layer. The signature of the Nisarg cyclone is reported in the Phased Array Doppler Sound Detection and Ranging (SODAR) data installed at the Center for Space and Atmospheric Science (CSAS), Sanjay Ghodawat University, Kolhapur (16.74° N, 74.37° E; near India's western coast). The vertical profile of wind speed and wind direction measured from the sodar system clearly reveals the signature of Nisarg cyclone during 2- 3 June 2020. Our analysis revealed that, the maximum mean wind speed was 17 m/s on 3rd June 2020 at 10:00 IST. It also shows the change in the wind direction from southwest to southeast on 2nd June 2020 and 3rd June 2020. Daily high-resolution reanalysis in the domain, 0-25°N, 65-110°E, during the period from 31st May-5th June 2020 shown the variation in atmospheric pressure of the Nisarg cyclone from 1000 to 1008 hPa, sea surface tremperature (SST) between 30 and 31°C, outgoing longwave radiation (OLR) varied between 100 and 240 Wm−2, wind speed between 3 and 15 m/s and low values of vertical wind shear (VWS) was observed to the north of the track Nisarg. These findings could aid in better understanding and forecasting in this region. The present results are initial measurements of sodar system.

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Analysis of Atmospheric Pollutants in Bucharest in Correlation with Meteorological Parameters

Revista de Chimie ◽

10.37358/rc.18.8.6463 ◽

2018 ◽

Vol 69 (8) ◽

pp. 2005-2011

Author(s):

Marin Rusanescu ◽

Carmen Otilia Rusanescu ◽

Gigel Paraschiv

Keyword(s):

Wind Speed ◽

Sulfur Dioxide ◽

Relative Humidity ◽

Air Temperature ◽

Wind Direction ◽

Meteorological Parameters ◽

Vertical Mixing ◽

Average Concentration ◽

Atmospheric Pollutants ◽

Traffic Pollutants

In this paper we analyze the correlation between meteorological parameters (wind speed and direction, relative humidity, air temperature) and atmospheric pollutants in Bucharest during the cold period 26.02.2018-02.03.2018, which was based on the monitoring of the concentrations of nitrogen oxides, NO2, O3 and SO2 sulfur dioxide within 24 h and the occurrence of exceedances above the prescribed limit. It was found based on the results obtained that the wind direction influences not only the concentrations of pollutants but also the correlation between the pollutants. Traffic pollutants were at the highest concentration when the wind speed was low. We have found that the highest average concentration for NO2, NOx, NO, O3 occurred at 90% indicative humidity for vertical mixing of strong pollutants. Sulfur dioxide did not record exceeding over the limit standard in the analyzed period.

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