scholarly journals The effects of temperature, humidity, and barometric pressure on short-sprint race times

2006 ◽  
Vol 84 (4) ◽  
pp. 311-324 ◽  
Author(s):  
J R Mureika
Keyword(s):  
Wind Speed ◽  
Numerical Model ◽  
Relative Humidity ◽  
Aerodynamic Drag ◽  
Barometric Pressure ◽  
Atmospheric Conditions ◽  
Gauge Reading ◽  
World Class ◽  
Effects Of Temperature ◽  
Performance Times

A numerical model of 100 m and 200 m world class sprinting performances is modified using standard hydrodynamic principles to include effects of air temperature, pressure, and humidity levels on aerodynamic drag. The magnitude of the effects are found to be dependent on wind speed. This implies that differing atmospheric conditions can yield slightly different corrections for the same wind-gauge reading. In the absence of wind, temperature is found to induce the largest variation in times (0.01 s per 10°C increment in the 100 m), while relative humidity contributes the least (under 0.01 s for all realistic conditions for 100 m). Barometric pressure variations at a particular venue can also introduce fluctuations in performance times on the order of a 0.01 s for this race. The combination of all three variables is essentially additive, and is more important for head-wind conditions that for tail-winds. As expected, calculated corrections in the 200 m are magnified due to the longer duration of the race. The overall effects of these factors on sprint times can be considered a ``second order'' adjustment to previous methods that rely strictly on a venue's physical elevation, but can become important in extreme conditions.PACS Nos.: 01.80, 02.60L

The atmospheric conditions affecting sporulation of blue mould in tobacco

1964 ◽  
Vol 4 (13) ◽  
pp. 178 ◽  
Author(s):  
BG Collins
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Air Temperature ◽  
Critical Parameter ◽  
Leaf Surface ◽  
Atmospheric Conditions ◽  
Blue Mould ◽  
Growing Seasons ◽  
Ambient Relative Humidity ◽  
Critical Relative Humidity

Conditions favouring sporulation of blue mould (Peronospora tabacina Adam) having been established in the laboratory, a theoretical model has now been used to express the critical parameter, i.e. the relative humidity near the leaf surface where the spores form, in terms of the ambient atmospheric conditions. To test the validity of this model, wind speed, air temperature, and relative humidity mere measured over four growing seasons in three tobacco crops in the Ovens Valley, Victoria, and related to times of sporulation of the mould observed concurrently in these crops. 'Critical relative humidity,' a function of wind speed, air temperature, and heat loss from the crop is shown to be a more serviceable indicator of likelihood of sporulation than either ambient relative humidity or rainfall.

scholarly journals Estimacion Del Potencial De Captura De Agua Atmosferica En Guásimas, Sonora

2018 ◽  
Vol 14 (9) ◽  
pp. 68
Author(s):  
Ana Laura Bautista-Olivas ◽  
Fidencio Cruz Bautista
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Ambient Temperature ◽  
Meteorological Station ◽  
Atmospheric Conditions ◽  
Atmospheric Water

This paper focuses on estimating the potential of the atmospheric conditions in the locality of Guásimas Sonora for the capture of atmospheric water. To achieve this goal, an automated meteorological station was installed to record the ambient temperature, relative humidity, wind speed, and precipitation at the study site. According to the results obtained, the potential of the atmospheric conditions for the capture of water in the locality of Guásimas, in general, is medium. It presents a period of 20 to 30 days a year to capture atmospheric water with passive collectors and between 105 and 130 days during the year for the condensation of atmospheric water with active collectors.

scholarly journals Effect of climatological factors on respiratory syncytial virus epidemics

2008 ◽  
Vol 136 (10) ◽  
pp. 1328-1332 ◽  
Author(s):  
D. E. NOYOLA ◽  
P. B. MANDEVILLE
Keyword(s):  
Respiratory Syncytial Virus ◽  
Relative Humidity ◽  
Barometric Pressure ◽  
Daily Temperature ◽  
Dew Point ◽  
Atmospheric Conditions ◽  
Regression Analyses ◽  
Maximum Daily Temperature ◽  
Explained Variation ◽  
Syncytial Virus

SUMMARYRespiratory syncytial virus (RSV) presents as yearly epidemics in temperate climates. We analysed the association of atmospheric conditions to RSV epidemics in San Luis Potosí, S.L.P., Mexico. The weekly number of RSV detections between October 2002 and May 2006 were correlated to ambient temperature, barometric pressure, relative humidity, vapour tension, dew point, precipitation, and hours of light using time-series and regression analyses. Of the variation in RSV cases, 49·8% was explained by the study variables. Of the explained variation in RSV cases, 32·5% was explained by the study week and 17·3% was explained by meteorological variables (average daily temperature, maximum daily temperature, temperature at 08:00 hours, and relative humidity at 08:00 hours). We concluded that atmospheric conditions, particularly temperature, partly explain the year to year variability in RSV activity. Identification of additional factors that affect RSV seasonality may help develop a model to predict the onset of RSV epidemics.

scholarly journals Sporulation of Bremia lactucae Affected by Temperature, Relative Humidity, and Wind in Controlled Conditions

2004 ◽  
Vol 94 (4) ◽  
pp. 396-401 ◽  
Author(s):  
H. Su ◽  
A. H. C. van Bruggen ◽  
K. V. Subbarao ◽  
H. Scherm
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Downy Mildew ◽  
Exposure Time ◽  
Stomatal Aperture ◽  
Bremia Lactucae ◽  
Wind Speeds ◽  
Controlled Conditions ◽  
Effects Of Temperature

The effects of temperature (5 to 25°C), relative humidity (81 to 100%), wind speed (0 to 1.0 m s-1), and their interactions on sporulation of Bremia lactucae on lettuce cotyledons were investigated in controlled conditions. Sporulation was affected significantly (P < 0.0001) by temperature, with an optimum at 15°C, and by relative humidity (RH), with sporulation increasing markedly at RH ≥ 90%. There was a significant effect of exposure time in relation to temperature (P = 0.0007) but not to RH. In separate experiments, both RH and wind speed significantly (P < 0.0001) affected the number of cotyledons with sporulation and the number of sporangia produced per cotyledon. No sporulation was observed at wind speeds of >0.5 m s-1, regardless of RH. In still air, the number of sporangiophores produced per cotyledon increased linearly with RH from 81 to 100% (P = 0.0001, r = 0.98). Histological observations indicated that sporulation may be affected by stomatal aperture in response to RH, as more closed stomata and correspondingly fewer sporangiophores were present at lower RH. These results are important for understanding the mechanism of RH effects on sporulation and for predicting conditions conducive to downy mildew development.

scholarly journals Potential Evapotranspiration Reduction and Its Influence on Crop Yield in the North China Plain in 1961–2014

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Wanlin Dong ◽  
Chao Li ◽  
Qi Hu ◽  
Feifei Pan ◽  
Jyoti Bhandari ◽  
...  
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Crop Yield ◽  
North China Plain ◽  
North China ◽  
Potential Evapotranspiration ◽  
The North ◽  
The North China Plain ◽  
Sunshine Hours ◽  
Humidity Index

Climate change has caused uneven changes in hydrological processes (precipitation and evapotranspiration) on a space-temporal scale, which would influence climate types, eventually impact agricultural production. Based on data from 61 meteorological stations from 1961 to 2014 in the North China Plain (NCP), the spatiotemporal characteristics of climate variables, such as humidity index, precipitation, and potential evapotranspiration (ET0), were analyzed. The sensitivity coefficients and contribution rates were applied to ET0. The NCP has experienced a semiarid to humid climate from north to south due to the significant decline of ET0 (−13.8 mm decade−1). In the study region, 71.0% of the sites showed a “pan evaporation paradox” phenomenon. Relative humidity had the most negative influence on ET0, while wind speed, sunshine hours, and air temperature had a positive effect on ET0. Wind speed and sunshine hours contributed the most to the spatiotemporal variation of ET0, followed by relative humidity and air temperature. Overall, the key climate factor impacting ET0 was wind speed decline in the NCP, particularly in Beijing and Tianjin. The crop yield in Shandong and Henan provinces was higher than that in the other regions with a higher humidity index. The lower the humidity index in Hebei province, the lower the crop yield. Therefore, potential water shortages and water conflict should be considered in the future because of spatiotemporal humidity variations in the NCP.

scholarly journals Effect Factors of Benzene Adsorption and Degradation by Nano-TiO2Immobilized on Diatomite

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Lijun Cheng ◽  
Yong Kang ◽  
Guishui Li
Keyword(s):  
Relative Humidity ◽  
Light Intensity ◽  
Experimental Results ◽  
Benzene Adsorption ◽  
Effect Factors ◽  
Benzene Concentration ◽  
Effects Of Temperature ◽  
Safe Concentration

Difference between adsorption of benzene by diatomite and nano-TiO2immobilized on diatomite was investigated. And effects of temperature, light intensity, relative humidity, and initial benzene concentration on adsorption and degradation of benzene by nano-TiO2immobilized on diatomite were also studied. The experimental results showed that when initial benzene concentration was2.2×10−3 mg L−1, it could be degraded to below safe concentration (1.1×10−4 mg L−1) after 50 h when temperature was 20°C, but it just needed 30 h at 35°C. When light intensity was 6750 Lx, it needed 30 h for benzene to be degraded to below safe concentration, but benzene could barely be degraded without light. When relative humidity was 50%, benzene could be degraded to1.0×10−4 mg L−1after 30 h, while its concentration could be reduced to7.0×10−5 mg L−1at the relative humidity of 80%.

Survival of Endocronartium harknessii teliospores in a simulated airborne state

1989 ◽  
Vol 67 (3) ◽  
pp. 928-932 ◽  
Author(s):  
Kan-Fa Chang ◽  
P. V. Blenis
Keyword(s):  
Relative Humidity ◽  
Liquid Nitrogen ◽  
Long Distance ◽  
Spider Webs ◽  
Considerable Potential ◽  
Good Ability ◽  
Endocronartium Harknessii ◽  
Spore Longevity ◽  
Effects Of Temperature ◽  
Increasing Temperature

The effects of temperature and relative humidity (RH) on the survival of Endocronartium harknessii teliospores and the longevity of these spores out of doors during daylight hours were studied. In one experiment, fresh and liquid-nitrogen-stored spores of E. harknessii were impacted onto spider webs or plastic threads and incubated in darkness at temperatures of 6, 15, and 24 °C and RHs of 39 and 98%. Survival was measured after 1, 2, 4, 8, and 16 days. Spore longevity decreased with increasing temperature and was lower at 98 than at 39% RH. In a second experiment, spores were impacted onto spider webs and placed out of doors on clear days. Viability decreased linearly with time and averaged 33% after 12 h. The data suggest that E. harknessii has relatively good ability to survive in an airborne state and thus would have considerable potential for long distance spread.

scholarly journals Evaluation of the AMPS Boundary Layer Simulations on the Ross Ice Shelf, Antarctica, with Unmanned Aircraft Observations

2017 ◽  
Vol 56 (8) ◽  
pp. 2239-2258 ◽  
Author(s):  
Jonathan D. Wille ◽  
David H. Bromwich ◽  
John J. Cassano ◽  
Melissa A. Nigro ◽  
Marian E. Mateling ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Wind Speed ◽  
Relative Humidity ◽  
High Wind ◽  
Ice Shelf ◽  
High Wind Speed ◽  
Near Surface ◽  
Ross Ice Shelf ◽  
Low Cloud ◽  
The Antarctic

AbstractAccurately predicting moisture and stability in the Antarctic planetary boundary layer (PBL) is essential for low-cloud forecasts, especially when Antarctic forecasters often use relative humidity as a proxy for cloud cover. These forecasters typically rely on the Antarctic Mesoscale Prediction System (AMPS) Polar Weather Research and Forecasting (Polar WRF) Model for high-resolution forecasts. To complement the PBL observations from the 30-m Alexander Tall Tower! (ATT) on the Ross Ice Shelf as discussed in a recent paper by Wille and coworkers, a field campaign was conducted at the ATT site from 13 to 26 January 2014 using Small Unmanned Meteorological Observer (SUMO) aerial systems to collect PBL data. The 3-km-resolution AMPS forecast output is combined with the global European Centre for Medium-Range Weather Forecasts interim reanalysis (ERAI), SUMO flights, and ATT data to describe atmospheric conditions on the Ross Ice Shelf. The SUMO comparison showed that AMPS had an average 2–3 m s−1 high wind speed bias from the near surface to 600 m, which led to excessive mechanical mixing and reduced stability in the PBL. As discussed in previous Polar WRF studies, the Mellor–Yamada–Janjić PBL scheme is likely responsible for the high wind speed bias. The SUMO comparison also showed a near-surface 10–15-percentage-point dry relative humidity bias in AMPS that increased to a 25–30-percentage-point deficit from 200 to 400 m above the surface. A large dry bias at these critical heights for aircraft operations implies poor AMPS low-cloud forecasts. The ERAI showed that the katabatic flow from the Transantarctic Mountains is unrealistically dry in AMPS.

Sign in / Sign up

Export Citation Format

Share Document