AGRICULTURAL METEOROLOGY: CORRELATION OF AIR TEMPERATURES IN CENTRAL AND SOUTHERN ALBERTA AND SASKATCHEWAN WITH LATITUDE, LONGITUDE AND ALTITUDE

1938 ◽  
Vol 16c (1) ◽  
pp. 16-26 ◽  
Author(s):  
J. W. Hopkins
Keyword(s):  
Air Temperature ◽  
Local Variation ◽  
Temperature Gradients ◽  
Regression Coefficients ◽  
Regression Equations ◽  
Partial Regression ◽  
Air Temperatures ◽  
Southern Alberta ◽  
Different Seasons ◽  
Agricultural Meteorology

Linear partial regression coefficients of the 18-year average (1917–34) monthly mean air temperature recorded at 43 points in central and southern Alberta and Saskatchewan on latitude, longitude, and altitude were determined for each month of the year. The three series of coefficients each show an independent seasonal trend. The decrease in air temperature with altitude is greatest in summer and least in winter, whereas the gradient associated with longitude is most pronounced in winter and least in evidence in summer. The influence of latitude is likewise most pronounced in winter, but shows two minima, in spring and autumn respectively. The monthly regression equations account for most of the variance of the station averages, and hence provide a reasonably satisfactory graduation of the climatological temperature gradients characteristic of this area at different seasons of the year.These regression equations could not, however, be applied satisfactorily to the monthly averages for individual years, owing to greater local variation. Additional equations were therefore determined from the records for 1935 at 27 stations in the sub-area bounded by the 50th and 52nd parallels and the 104th and 108th meridians. The results suggest that further additions to the number of stations would still be desirable, and that if this was effected a fairly accurate graduation should be possible within this district, even in individual years.

AGRICULTURAL METEOROLOGY: CORRELATION OF MONTHLY PRECIPITATION IN CENTRAL AND SOUTHERN ALBERTA AND SASKATCHEWAN WITH LATITUDE, LONGITUDE AND ALTITUDE

1938 ◽  
Vol 16c (5) ◽  
pp. 214-224
Author(s):  
J. W. Hopkins
Keyword(s):  
Air Temperature ◽  
Regression Coefficients ◽  
Quadratic Term ◽  
Monthly Precipitation ◽  
Partial Regression ◽  
Southern Alberta ◽  
The Subject ◽  
Complete Specification ◽  
Agricultural Meteorology

The linear partial regression coefficients of the 19-ycar average (1917–1935) monthly precipitation recorded at 42 points in central and southern Alberta on latitude, longitude and altitude were determined for each month of the year. The correlation of precipitation with these co-ordinates, although statistically significant, was only moderate. Some improvement was effected by inclusion of the quadratic term in longitude, but even so, more than 50% of the inter-station variance of the 19-year precipitation averages for most months remained in the form of residual deviations. Observations for individual years were even less amenable to graduation. Consequently, a given number of meteorological stations would provide a much less complete specification of precipitation than of air temperature (the subject of a parallel previous study) within the area considered.

scholarly journals Variations of indicative dates of ice regime on Lake Onego based on ground air temperature

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Vyacheslav N. Baklagin
Keyword(s):  
Air Temperature ◽  
Regression Equations ◽  
Early Formation ◽  
Air Temperatures ◽  
Ice Regime ◽  
Break Up ◽  
Ice Period ◽  
Ice Phenomena

The paper shows the changes in the dates (complete freeze-up, ±5 days/°C and complete ice clearance, ±3 days/°C) of the ice regime in Lake Onego depending on changes in average air temperature within the preceding two-month periods (autumn and spring). The regression equations for their calculation based on previous three- and four-month periods according to the 2000-2018 data are also provided. Indicative dates of ice regime based on accumulated air temperatures within the ice period of Lake Onego were also established (early formation of ice phenomena, complete freeze-up phase, beginning of the break-up phase and complete ice clearance). Together with the data on expected air temperature above the lake’s surface, these dependencies enable us to predict the indicative dates of the ice regime.

scholarly journals The impact of the air temperature on measuring the zenith angle during the year in the ground layer of the atmosphere for the needs of engineering surveying

2021 ◽  
Vol 61 (3) ◽  
pp. 476-488
Author(s):  
Tomáš Suk ◽  
Martin Štroner
Keyword(s):  
Czech Republic ◽  
Numerical Model ◽  
Central Europe ◽  
Air Temperature ◽  
Zenith Angle ◽  
Geographical Area ◽  
Temperature Gradients ◽  
The Czech Republic ◽  
Different Seasons ◽  
The Impact

This paper presents the results of over a year-long experiment dealing with a temperature measurement to calculate the theoretical effect of the atmosphere on the measured zenith angle in engineering surveying. The measurements were performed to determine the accurate and specific temperatures (temperature gradients), which can be recorded in different seasons in the low level of the atmosphere (up to 2 m above the ground, where most Engineering Surveying measurements take place) for the geographical area of Central Europe - specifically the Czech Republic. A numerical model was then applied to the resulting determined temperature gradients to calculate the path of the beam passing through an inhomogeneous atmosphere. From these values, the apparent vertical shifts caused by refraction in a given environment and time were finally determined.

COMPARISON OF OBSERVATIONS AND MACROCLIMATIC MODEL ESTIMATES OF MONTHLY WINTER SOIL TEMPERATURES AT OTTAWA

1985 ◽  
Vol 65 (1) ◽  
pp. 109-122 ◽  
Author(s):  
L. M. DWYER ◽  
H. N. HAYHOE
Keyword(s):  
Snow Cover ◽  
Predictive Models ◽  
Regression Models ◽  
Stepwise Regression ◽  
Regression Coefficients ◽  
Data Sets ◽  
Regression Equations ◽  
Grass Cover ◽  
Partial Regression ◽  
Soil Temperatures

Estimates of monthly soil temperatures under short-grass cover across Canada using a macroclimatic model (Ouellet 1973a) were compared to monthly averages of soil temperatures monitored over winter at Ottawa between November 1959 and April 1981. Although the fit between monthly estimates and Ottawa observations was generally good (R for all months and depths 0.10, 0.20, 0.50, 1.00 and 1.50 m was 0.90), it was noted that midwinter estimates were generally below observed temperatures at all soil depths. Data sets used in the development of the original Ouellet (1973a) multiple regression equations were collected from stations across Canada, many of which have reduced snow cover. It was found that the buffering capability of the snow cover accumulated at Ottawa during the winter months was underestimated by the pertinent partial regression coefficients in these equations. The coefficients were therefore modified for the Ottawa station during the winter months. The resultant regression models were used to estimate soil temperature during the winters of 1981–1982 and 1982–1983. Although the Ottawa-based models included fewer variables because of the smaller data base available from a single site, comparisons of model estimates and observations were good (R = 0.84 and 0.91) and midwinter estimates were not consistently underestimated as they were using the original Ouellet (1973a) model. Reliable monthly estimates of soil temperatures are important since they are a necessary input to more detailed predictive models of daily soil temperatures. Key words: Regression model, snowcover, stepwise regression, variable selection

scholarly journals Regression analysis of milk production traits in simmental cows

2011 ◽  
Vol 27 (4) ◽  
pp. 1433-1441
Author(s):  
M.D. Petrovic ◽  
V. Bogdanovic ◽  
M.M. Petrovic ◽  
S. Rakonjac
Keyword(s):  
Regression Analysis ◽  
Milk Production ◽  
Milk Fat ◽  
Regression Coefficients ◽  
Regression Equations ◽  
Production Traits ◽  
Milk Production Traits ◽  
Partial Regression ◽  
Three Generations ◽  
Lactation Length

The relationship between milk production traits over whole lactations was evaluated across three generations of Simmental cows, i.e. between daughters, dams and grand dams, by a phenotypic regression analysis with whole lactation traits in the daughter generation being used as the dependent variables (x1), and those in the dam and grand dam generations being used as the independent variables (x2 and x3). The results were obtained from a sample of 1170 daughters and as many dams and grand dams. The significance of the partial regression coefficients b2 and b3 was separately evaluated by a t-test. An analysis of variance was used to estimate the significance of the simultaneous effect of the production traits of dams and grand dams on the milk production achieved in the daughter generation. The calculated value of the partial regression coefficients for the whole lactation production traits across three generations (grand dams, dams and daughters) and their statistical significances determined by the t and F tests, as well as the regression equations used, suggested that the effect of the grand dam generation on the milk production traits in granddaughters was substantially lower than the effect of dams. The calculated partial regression coefficients (b2 and b3) were positive and statistically very significant (P<0.01), excepting the regression coefficients b3 for lactation length and b2 for milk fat content that were not statistically significant (P>0.05). A very significant change (P<0.01) was observed in all production traits in the daughter generation as simultaneously affected by the traits in the dam and grand dam generations.

Comparison of Experimental and Numerical Air Temperature Distributions Behind a Cylindrical Volumetric Solar Absorber Module

2007 ◽  
Vol 130 (1) ◽  
Author(s):  
Silvia Palero ◽  
Manuel Romero ◽  
José L. Castillo
Keyword(s):  
Air Temperature ◽  
Radial Distribution ◽  
Current Trend ◽  
Temperature Gradients ◽  
Outlet Temperature ◽  
Recirculation Flow ◽  
Solar Absorber ◽  
Air Temperatures ◽  
Wind Influence ◽  
Solar Receiver

The current trend in volumetric solar receiver technology is to build modular receivers cooled by air (Hitrec I and II, Solair 200kW and 3MW) in order to facilitate the replacement of broken absorber modules (cups) and to simplify the upscaling of the receiver. In addition, the modular designs include an air return circuit to cool down the structure supporting the cups. Usually, the air outlet temperature from each module is characterized by measurements taken from a single thermocouple. However, the air temperature distribution behind the volumetric absorber module is not homogeneous, as it can be seen in some specific tests where several thermocouples were added behind different absorber modules. The radial distribution of outlet air temperatures shows very high temperature gradients. The goal of this work is to explain the inhomogeneous thermal maps behind the metallic absorbers by comparing some experimental results with numerical simulations performed using the computational fluid dynamics FLUENT code. The results show the wind influence over the air recirculation flow and its effects on the outlet air temperature radial distribution. Thus, the simulations suggest different ways to reduce the temperature gradients behind each cup.

The Effects of Rainfall and Temperature on Percolation Through Drain Gauges

1934 ◽  
Vol 24 (1) ◽  
pp. 105-135 ◽  
Author(s):  
R. S. Koshal ◽  
R. A. Fisher
Keyword(s):  
Numerical Methods ◽  
Soil Mass ◽  
Rate Of Change ◽  
Regression Coefficients ◽  
Standard Errors ◽  
Regression Equations ◽  
Partial Regression ◽  
Direct Knowledge ◽  
The Mean ◽  
Partial Depletion

Summary1. Partial regression equations representing the average drainage observed in any month in terms of the temperature and rainfall of that month, and including terms representing the mean secular rate of change of the drainage discharge and of its regression coefficients on rainfall and temperature, have been fitted to the thirty-six series of observations provided by the three Rothamsted drain gauges in the twelve months of the year.2. An account is given of adequate and direct numerical methods of handling equations involving observed quantities, and chosen functions of them, as independent variates, and of calculating standard errors appropriate to the several sorts of comparison which are to be made.3. In the absence of direct knowledge of the amount of water contained from time to time in the soil mass of the gauge it has been customary to assume that the lower average drainage of the summer months is directly due to a greater amount of evaporation taking place in these months. The results of the present enquiry direct attention to a second possibility, namely that the water content of the gauges differs considerably at different times of the year, and that the high drainage in winter is in part to be ascribed to the accumulation of water during the rainy months of autumn, while the lower drainage in summer is due to the partial depletion of the gauges during the lower rainfall of the spring months.

scholarly journals UNHEATED ENVIRONMENTS FOR OVERWINTERING NURSERY PLANTS IN CONTAINERS

1980 ◽  
Vol 60 (3) ◽  
pp. 895-902 ◽  
Author(s):  
R. L. DESJARDINS ◽  
CALVIN CHONG
Keyword(s):  
Linear Relationship ◽  
Snow Cover ◽  
Air Temperature ◽  
Plant Protection ◽  
Storage Condition ◽  
Regression Coefficients ◽  
Good Linear ◽  
Plastic Structure ◽  
Good Protection ◽  
Air Temperatures

Nineteen unheated environments, including 12 under plastic structure, 6 under structureless blanket cover, and a control, were monitored and compared for their effectiveness in protecting nursery plants in containers during the winter. A relatively good linear relationship was found between the minimum daily air temperatures outside (control) and the minimum daily temperatures of both air and container within the various environments. From these relationships, regression coefficients were found that could be used for predicting the minimum air and container temperatures within the protected environments using outside air temperature. As indicated by post-winter storage condition of selected cultivars, all environments with snow cover under plastic structure or under blanket cover provided good plant protection, while similar environments without snow cover were less effective. Over-the-canopy protection with Microfoam insulation during the coldest months provided good protection in polyhouse environments without snow cover. Based on the regression coefficients and on the post-winter storage condition of plants, the environments were classified into three major groups: regression coefficients ranging from 0.2 to 0.4 for environments providing good protection; from 0.4 to 0.5 for those providing intermediate protection; and from 0.5 to 0.7 for those providing poor protection. A technique is presented to determine which types of environment are likely to be successful in other locations across Canada.

INVESTIGATIONS ON THE RELATIONSHIP BETWEEN WINTERHARDINESS IN ROSES AND THE ELECTRIC IMPEDANCE MEASURED DURING THE GROWING PERIOD

1966 ◽  
Vol 46 (4) ◽  
pp. 441-448 ◽  
Author(s):  
Felicitas Svejda
Keyword(s):  
Air Temperature ◽  
Temperature Gradients ◽  
Regression Coefficients ◽  
Electric Impedance ◽  
Impedance Measurements ◽  
Growing Period ◽  
The Relationship

Differences were found in the electric impedance of rose cultivars and seedlings, measured periodically under greenhouse and field cultures. Generally, plants with the highest ranking means were also hardy, but the magnitude of the impedance was not strictly indicative of hardiness since hardy plants were found with relatively low impedances.Fluctuations in the weekly impedance measurements corresponded to the rise and fall of the air temperature. The impedance was negatively correlated to the temperature. Different impedance temperature regression coefficients were were found for different cultivars and seedlings. It is not known how these temperature gradients should be interpreted biologically, but it is assumed that they are significant for the adaptation of plants.

scholarly journals Spatial variability of air temperature in a free-stall in the Northeastern semi-arid region of Brazil

2016 ◽  
Vol 20 (1) ◽  
pp. 67-71
Author(s):  
Indira C. M. Gonçalves ◽  
Silvia H. N. Turco ◽  
Clóvis M. C. Ramos
Keyword(s):  
Spatial Variability ◽  
Air Temperature ◽  
Production Environment ◽  
Planning And Control ◽  
Air Temperatures ◽  
Shade Cloth ◽  
Different Seasons ◽  
Semi Arid Region ◽  
And Control ◽  
Kriging Maps

ABSTRACT The knowledge on the spatial variability of climatic attributes and the building of Kriging maps can assist in the design and management of confined animal facilities, by allowing a spatial visualization that is helpful for the planning and control of information from the production environment. The study aimed to characterize the spatial variability of air temperature in a free-stall barn used for dairy cattle confinement located in Petrolina-PE, Brazil, in different seasons and at different times. The variable air temperature was recorded at 136 points distributed in the areas under the shed and the shade cloth for the study of spatial variability and the construction of maps by Kriging. Air temperature data was collected in the winter and in the summer, in the months of July and August (2013) and January and February (2014), at different times (9 and 15 h). According to the results, the use of geostatistics enabled to define areas with different spatial variabilities in air temperature and specific areas in the free-stall with values higher than the recommended levels for thermal comfort. In addition, the central part of the facility is the region with the lowest values of air temperatures, due to the presence of a ridge vent.

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