diurnal variation


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Related to diurnal variation: diurnal variation of temperature

diurnal variation

[dī′ərn·əl ‚ver·ē′ā·shən]
(geophysics)
Daily variations of the earth's magnetic field at a given point on the surface, with both solar and lunar periods having their source in the horizontal movements of air in the ionosphere.
References in periodicals archive ?
The diurnal variation of thunderstorm frequency has been documented since the early 1920s from Wilson (1921), Whipple (1929), and the famous Carnegie curve (Israel 1971; Wallace 1975; Williams and Heckman 1993), and more recently by regional (e.
The individual diurnal variation of hs-cTnT is significantly described by a cosinor model.
On the other hand, urinary markers of nucleic acid oxidation did not have diurnal variation in healthy subjects [18].
The sinusoidal curve is considered to be the most adequate for expressing diurnal variations.
The mechanism controlling the diurnal variation of the IOP as well as daily variations in many other physiological "Constants" (Circadian fluctuations) appears to be situated at some distance from the eye, possibly in the hypothalamus and might act upon the IOP by producing changes in one or more of three factors determining variations in the "Steady-State"- the production of aqueous, the resistance to aqueous outflow or the episcleral venous pressure- but the exact mechanism is not yet clear.
Because the natural diurnal variation in testosterone levels tends to diminish with age, it is acceptable to test men ages 45 and older before 2 pm.
The purpose of this study was to find out the diurnal variation in cardiovascular endurance performance in the young athletes.
All these cases were studied irrespective of their age and gender, and we also tried to find out the seasonal and diurnal variations, if any, in cases of electrocution.
In this situation, diurnal variation in vision is a useful indicator that the corneal pathology is at least contributing to symptoms.