The excitation of atmospheric oscillations

An investigation is made into the excitation of large-scale atmospheric oscillations by the direct absorption of incoming solar radiation by atmospheric ozone. The atmospheric temperature profile is chosen to agree favourably with the main features of the observed temperature distribution, particularly as regards the maximum around the 50 km height; this distribution is shown to be non-resonant as far as the solar semidiurnal component is concerned. The excited solar diurnal, semidiurnal and terdiurnal pressure oscillations are computed and we find that although the largest Fourier component in the heating is the diurnal term , the tide it excites is small in keeping with observation. On the other hand, the excited semidiurnal oscillation is much larger than that due to any previously considered thermal mechanism . It is found that the main semidiurnal and terdiurnal tides generated by the direct absorption of insolation by ozone as calculated in the present work, together with published results regarding water vapour absorption, can adequately account for the observed values at ground level. The seasonal variations of the semi and terdiurnal tides are also calculated and these agree extremely well with observation. Finally, the change of phase of 180° in the vertical distribution of the solar semidiurnal oscillation, which is expected from the analysis of the quiet day magnetic variation, is accounted for in the present work.

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The role of updrafts in the scaling of extreme precipitation in mid-latitudes

10.5194/egusphere-egu21-13571 ◽

2021 ◽

Author(s):

Falco Bentvelsen ◽

Geert Lenderink ◽

Pier Siebesma

Keyword(s):

Extreme Precipitation ◽

Large Scale ◽

Atmospheric Temperature ◽

Geophysical Research ◽

Cloud Properties ◽

Cloud Dynamics ◽

Large Eddy ◽

Atmospheric Temperature Profile ◽

Strong Surface ◽

Cloud Cores

We investigate the hypothesis that invigoration of convective updrafts under warming conditions contributes to the stronger than Clausius-Clapeyron (CC) scaling. Focus is on a mid-latitude case of extreme precipitation, based on idealised forcing conditions derived for the Netherlands, with strong surface forcing as well as strong forcing from large-scale rising motion associated with the passage of a synoptic scale low pressure or frontal system. Various Large Eddy Simulations (LES) of this composite case have been performed on a 192x192 km domain. By systematically perturbing the atmospheric temperature profile, a large response of cloud dynamics to warming with larger and more vigorous cloud structures in the warmer runs has been found.*Here, we study these cloud dynamics further by investigating the vertical wind velocity in the cloud (cores). Updrafts play a key role in rain formation by transporting moisture upward in the clouds. We will demonstrate how the distributions of these vertical velocities near the surface and at different levels in the clouds respond to warming in this mid-latitude setting and how they relate to cloud properties as cell size and buoyancy.&#160;*Lochbihler, K., Lenderink, G., and Siebesma, A. P. (2019). Response of extreme precipitating cellstructures to atmospheric warming. Journal of Geophysical Research: Atmospheres

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Deterministic and Empirical Approach for Millimeter-Wave Complex Outdoor Smart Parking Solution Deployments

Sensors ◽

10.3390/s21124112 ◽

2021 ◽

Vol 21 (12) ◽

pp. 4112

Author(s):

Fidel Alejandro Rodríguez-Corbo ◽

Leyre Azpilicueta ◽

Mikel Celaya-Echarri ◽

Peio Lopez-Iturri ◽

Ana V. Alejos ◽

...

Keyword(s):

Large Scale ◽

Radio Channel ◽

Path Loss ◽

Ground Level ◽

Directional Antennas ◽

Scale Parameters ◽

Parking Lot ◽

Smart Parking ◽

Wireless Communications Systems

The characterization of different vegetation/vehicle densities and their corresponding effects on large-scale channel parameters such as path loss can provide important information during the deployment of wireless communications systems under outdoor conditions. In this work, a deterministic analysis based on ray-launching (RL) simulation and empirical measurements for vehicle-to-infrastructure (V2I) communications for outdoor parking environments and smart parking solutions is presented. The study was carried out at a frequency of 28 GHz using directional antennas, with the transmitter raised above ground level under realistic use case conditions. Different radio channel impairments were weighed in, considering the progressive effect of first, the density of an incremental obstructed barrier of trees, and the effect of different parked vehicle densities within the parking lot. On the basis of these scenarios, large-scale parameters and temporal dispersion characteristics were obtained, and the effect of vegetation/vehicle density changes was assessed. The characterization of propagation impairments that different vegetation/vehicle densities can impose onto the wireless radio channel in the millimeter frequency range was performed. Finally, the results obtained in this research can aid communication deployment in outdoor parking conditions.

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On the vertical distribution of Phlebotomine sandflies (Dipt., Psychodidae) in British Honduras (Belize)

Bulletin of Entomological Research ◽

10.1017/s000748530000362x ◽

1970 ◽

Vol 59 (4) ◽

pp. 637-646 ◽

Cited By ~ 17

Author(s):

Paul Williams

Keyword(s):

Ground Level ◽

Insect Host ◽

Leishmania Mexicana ◽

Light Traps ◽

Principal Vector ◽

New Information ◽

Phlebotomine Sandflies ◽

British Honduras ◽

The Vertical Distribution ◽

Blood Meals

Phlebotomine sandflies were collected simultaneously at ground level, 25 ft and 40 ft in an area of medium bush in British Honduras (Belize).Flies were captured on human bait, with rat-baited oil-traps and with miniature light-traps, and some resting individuals were collected at each level. One species of Brumptomyia França and 18 of Lutzomyia França & Parrot were obtained. Brief notes on some of these species are given.Miniature light-traps provided the widest range of species, were the most satisfactory means for collecting Brumptomyia, L. steatopyga (Fairchild & Hertig) and L. carpenteri (Fairchild & Hertig), and yielded new information on the flight activities of L. deleoni (Fairchild & Hertig) and L. panamensis (Shannon).Most species collected were found to be predominantly arboreal in habit, L. permira (Fairchild & Hertig) and Lutzomyia sp. P being almost exclusively so. Some species (L. panamensis, possibly L. geniculata (Mangabeira) and L. bispinosa (Fairchild & Hertig)) live amongst the foliage but descend to the forest floor to seek blood-meals. A few species (L. steatopyga, L. deleoni and L. olmeca (Vargas & Díaz Nájera)) are active mainly near the ground, though the occasional specimen may be carried much higher.L. olmeca is the principal vector of rodent leishmaniasis in British Honduras. In the present study, no evidence was obtained to incriminate any other species of Phlebotomine as an insect host for Leishmania mexicana, and the mode of transmission of the parasite to man remains obscure.

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Penetration of large-scale electrostatic fields generated in the ionospheric dynamo region into the atmosphere at ground level and at altitudes in the F region

Radiophysics and Quantum Electronics ◽

10.1007/bf01038125 ◽

1976 ◽

Vol 19 (10) ◽

pp. 1043-1048

Author(s):

B. N. Gershman ◽

A. V. Samsonov

Keyword(s):

Large Scale ◽

Ground Level ◽

Ionospheric Dynamo ◽

F Region ◽

Electrostatic Fields

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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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Current and future occurrences of health-relevant, compound heat and ozone pollution events in six European ozone-temperature regions

10.5194/ems2021-61 ◽

2021 ◽

Author(s):

Sally Jahn ◽

Elke Hertig

Keyword(s):

Climate Change ◽

Air Temperature ◽

Large Scale ◽

Coupled Model ◽

Ground Level ◽

Future Climate Change ◽

Ozone Pollution ◽

Ground Level Ozone ◽

Ozone Concentrations ◽

Elevated Ozone

Air pollution and heat events present two major health risks, both already independently posing a significant threat to human health and life. High levels of ground-level ozone (O3) and air temperature often coincide due to the underlying physical relationships between both variables. The most severe health outcome is in general associated with the co-occurrence of both hazards (e.g. Hertig et al. 2020), since concurrent elevated levels of temperature and ozone concentrations represent a twofold exposure and can lead to a risk beyond the sum of the individual effects. Consequently, in the current contribution, a compound approach considering both hazards simultaneously as so-called ozone-temperature (o-t-)events is chosen by jointly analyzing elevated ground-level ozone concentrations and air temperature levels in Europe.Previous studies already point to the fact that the relationship of underlying synoptic and meteorological drivers with one or both of these health stressors as well as the correlation between both variables vary with the location of sites and seasons (e.g. Otero et al. 2016; Jahn, Hertig 2020). Therefore, a hierarchical clustering analysis is applied to objectively divide the study domain in regions of homogeneous, similar ground-level ozone and temperature characteristics (o-t-regions). Statistical models to assess the synoptic and large-scale meteorological mechanisms which represent main drivers of concurrent o-t-events are developed for each identified o-t-region.Compound elevated ozone concentration and air temperature events are expected to become more frequent due to climate change in many parts of Europe (e.g. Jahn, Hertig 2020; Hertig 2020). Statistical projections of potential frequency shifts of compound o-t-events until the end of the twenty-first century are assessed using the output of Earth System Models (ESMs) from the sixth phase of the Coupled Model Intercomparison Project (CMIP6).Hertig, E. (2020) Health-relevant ground-level ozone and temperature events under future climate change using the example of Bavaria, Southern Germany. Air Qual. Atmos. Health. doi: 10.1007/s11869-020-00811-zHertig, E., Russo, A., Trigo, R. (2020) Heat and ozone pollution waves in Central and South Europe- characteristics, weather types, and association with mortality. Atmosphere. doi: 10.3390/atmos11121271Jahn, S., Hertig, E. (2020) Modeling and projecting health&#8208;relevant combined ozone and temperature events in present and future Central European climate. Air Qual. Atmos. Health. doi: 10.1007/s11869&#8208;020&#8208;009610Otero N., Sillmann J., Schnell J.L., Rust H.W., Butler T. (2016) Synoptic and meteorological drivers of extreme ozone concentrations over Europe. Environ Res Lett. doi: 10.1088/ 1748-9326/11/2/024005

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Cultivation of Milky Mushroom (Calocybeindica) in Greenhouse

Current Journal of Applied Science and Technology ◽

10.9734/cjast/2021/v40i931348 ◽

2021 ◽

pp. 63-69

Author(s):

P. Indraja ◽

M. Madhava ◽

S. Satyam ◽

P. R. Chandra ◽

S. Joy Prince

Keyword(s):

Relative Humidity ◽

Traditional Method ◽

Large Scale ◽

Nutritive Value ◽

Edible Mushroom ◽

Atmospheric Temperature ◽

The Other ◽

Controlled Environment ◽

Mushroom Cultivation ◽

Experimental Conditions

Mushroom cultivation is one of the most important steps in diversification of agriculture. Milky mushroom (Calocybeindica) is a tropical edible mushroom, popular because of its good nutritive value and it can be cultivated commercially on large scale. Generally, by creating controlled environment in rooms mushroom cultivation is taken up, In traditional method it is typical to manage the atmospheric temperature and humidity in desired range, which can be maintained easily in greenhouse by automatic control system.Cultivation of milky mushroom in greenhouse was taken up in controlled environment under three different conditions of controlled temperature and relative humidity (RH). The experimental conditions are 28°C and 79% RH, 24°C and 84% RH and 32°C and 72%RH. The yield obtained was found maximum at 24°C temperature and 84% relative humidity when compared with the other two greenhouse environment conditions. The yield from the mushroom cultivation under controlled environmental conditions in greenhouse was found to be high when compared with the conventional practice. It was concluded that, the mushroom cultivation yields high under controlled greenhouse conditions and also economical compared to the conventional method.

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