In geosciences, an annual cycle is the part of a measured quantity's fluctuation that is attributed to Earth's changing position in orbit over the course of the year. Such quantities might be influenced directly (e.g. incoming solar radiation at a point at the surface) or indirectly (e.g. stratospheric westerlies and easterlies over the winter and summer hemispheres, resp.) by orbital position.
The annual cycle is commonly estimated from observational data or model output by taking the average of all Januaries, all Februaries, and so forth. If the observational record is long enough and conditions are stationary (i.e. there is no significant long-term trend), a meaningful annual cycle will result that can be used to calculate an anomaly time series.
(Note that grouping data according to the months in the Gregorian calendar makes an implicit assumption that the annual cycle in question is the vernal equinoxtropical year followed by that calendar. However, the annual cycle for some phenomena may be a different kind of year; see the seasonal year article for discussion.)
Once all these things are in place, the result is glorious: from arrival day for the new freshmen to the sights and sounds of graduation, and all the joys and sorrows in between, the annualcycle of a residential college is one of the most beautiful things in the world.
The cycle of a particular academic year actually begins many months in advance of the year in question, since the first part of it is the admission of new members into the college.
You should also consider sponsoring an annual literary contest in the spring, one that is open to undergraduates in the college or perhaps to the university as a whole.
The relative importance of the processes responsible for the annualcycle in the upper ocean heat content in the Peru Current, in the southeastern tropical Pacific, was diagnosed from an oceanic analysis dataset.
The annualcycle of the albedo associated with low-level clouds enhances the annualcycle in insolation, which explains the relatively strong annualcycle of heat content.
The annualcycle in SST is also relatively small, which is probably due to the changes in the temperature of the water entrained into the mixed layer associated with the thermocline motions, but also to a mixed layer deeper than that closer to the coast.
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