annual variation


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Related to annual variation: seasonal variation

annual variation

[′an·yə·wəl ver·ē′ā·shən]
(astronomy)
The change in the right ascension and declination of a star during one year, due to the combined effect of the star's proper motion and the precession of the equinoxes.
(geophysics)
A component in the change with time in the earth's magnetic field at a specified location that has a period of 1 year.

annual variation

The quantum of yearly change in variation at a place. This is normally indicated on the bottom of a map or chart and must be added/subtracted to/from the figure given on the map after taking into consideration the number of years elapsed since the last survey for the map. Variation is the angular difference between the direction of true north and magnetic north at any given point.
References in periodicals archive ?
Sea-level altitude and the mean and annual variation of land-surface temperature for daytime and nighttime were predictors in our model.
There was no annual variation in mean mass of eggs in clutch ([F.
Moreover, values of the maximum annual variation have the same trend in Leptosols and Regosols.
Dell and her co-authors use annual variation in temperature and precipitation over the past 50 years to examine the impact of climatic changes on economic activity throughout the world.
4% in 2006, causing an annual variation of prices by 3.
But whatever the reason, if a consistently high yield is what you want I'd strongly advise you to go for varieties with both a high average yield rating and a low annual variation around it.
There was no significant difference in annual variation in mean litter weight over three years, but seasonal variation was highly significant with spring having the highest litter weight (Table 6).
Seasonal or annual variation in mite infestation has been observed in other hosts (Morlan 1952; Howell et al.
barbouri, we caution against extending this interpretation to populations in nature or to other amphibian species for the following reasons: a) causes of postmetamorphic mortality in the laboratory may not match those in the field; b) there is documented annual variation in the effects of atrazine on amphibians (Rohr et al.
The present study focuses on the annual variation in mass concentration of P[M.
Annual variation in temperature and precipitation was not correlated with the number of eggs laid or embryos surviving in these populations.

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