It is finally the time of year to emerge from near hibernation, ditch our jackets, shake off our grumpy dispositions, and embrace spring. In a matter of a few days, our dead college campuses have literally come back to life. Skies are bluer, mornings brighter, the air warmer, and everything simply seems -- better. As I sat outside in the center of campus this past week, enjoying the weather and watching the amazing spectacle of people frolicking in the sunshine, I started to wonder why spring fever exists --scientifically, of course. What is it in our bodies, brains, and hormones that just makes us so much happier in the springtime?

An article in the Journal of the Association for Psychological Science states that "pleasant weather improves mood and broadens cognition," which proves that there is a relationship between good weather and happy moods. But where does this relationship come from? Scientifically, one must approach this question from various perspectives, simply because there could be lots of explanations as to why warmth + sunshine = happiness.

For instance, if you happened to ask a typical doctor why you suddenly seem in much better spirits over the past few days, he or she would probably hardly look at you while muttering "spring fever" before returning to more pressing business. The term "spring fever" is, in fact, an oxymoron, because it is actually a sign that your body "is in good working order," according to medical meteorologist Gerhard Lux of the DWD weather service. People have always been sensitive to weather, and during the change in seasons, different parts of the brain become activated.

However, if you were feeling determined and wanted some more information, you could ask an endocrinologist about your sudden onset of "spring fever." As someone who specializes in the study of hormones, an endocrinologist would say that spring fever is caused by a change in hormonal balance due to the sun's rays. Helmut Schatz, spokesman for the German Society of Endocrinology, explains that when more light hits the eye on the growing days of spring, the pineal gland responds and tells the brain to cease production of melatonin, the sleep hormone. Meanwhile, levels of serotonin, the hormone that stimulates happiness, increase when it is sunny. The combination of these two changes in hormonal levels, therefore "makes us more lively."

But we can't stop there, because now you want to know exactly what light has to do with anything here. So you finally ask a psychologist, specifically Peter Walschburger, professor of biopsychology at the Freie Universität Berlin, why good weather improves mood, he would say it has to do with visible light levels. Humans are naturally programmed to be active when it is light outside, and rest when it is dark. Therefore, activity and human behavior change dramatically when the sun comes out on nicer, spring days. Walschburger says, "We react massively to light. Suddenly there are a lot of people out and about, so you have a tendency to go outside."

Additionally, the body's internal clock, which controls the body's circadian rhythms (the 24-hour cycles of body temperature, hormonal secretion, and sleep) is directly affected physiologically by bright light, according to Dr. Michael Terman, director of the Light Therapy Unit at the New York State Psychiatric Institute at Columbia-Presbyterian Medical Center in Manhattan. ''For humans, early morning bright light is a particularly critical signal for keeping the body in synch for day and night.'' Thus, as the days grow longer and the duration of sunlight per day extends, people start to sleep less and eat less, but also feel less depressed and more energized.

In essence, the feeling you are experiencing right now, spring fever as it is commonly deemed, is a combination of timing, the natural human body program, hormones, and most importantly, light. So for the next few weeks, relish in the happiness you are feeling, because this junction of events only happens for a short time each year. Go lay outside in the sun, run around, or get some ice cream -- whatever floats your happy boat.