If you need a mood booster, it's just around the corner. 

A new study shows that getting outside and taking a walk in an urban park or other green space has even more power to increase happiness than the holiday season around Christmas.

"In cities, big green spaces are very important for people's sense of well-being," says Aaron Schwartz, a University of Vermont graduate student who led research that looked at the emotional sentiment people expressed on Twitter around visits to parks.

"This is the first study that uses Twitter to examine how user sentiment changes before, during, and after visits to different types of parks," says Schwartz.

The researchers analyzed 4,688 tweets publicly geotagged from parks within the city of San Francisco. Using a tool called the hedonometer that measures the "psychological valence" or emotional temperature of words, they were able to essentially score the amount of happiness reflected in each tweet. 

"We found that, yes, across all the tweets, people are happier in parks," Schwartz explained. "But the effect was stronger in large regional parks with extensive tree cover and vegetation... The greener parks show a bigger boost."

Little neighborhood parks produced a smaller mood boost, and plazas or squares dominated by concrete resulted in the least amount of happiness elevation.

The researchers report the increase in happiness seen in tweets from San Francisco's parks is equivalent to the boost seen on Christmas Day, when people tend to have a day to spend with loved ones and away from work. 

The study didn't cover the sentiment boosting powers of going even further afield, say deep into the forest or wilderness, but it seems to me the pattern of an even bigger boost might hold. People often have transformative experiences on long backpacking trips or other wilderness experiences. Makes you wonder if pavement is like kryptonite for happiness. 

"Being in nature offers restorative benefits on dimensions not available for purchase in a store, or downloadable on a screen," says Chris Danforth, a professor of mathematics at the University of Vermont.

While a growing heap of research shows associations between time in nature and happiness, Danforth says "the specific causal links are hard to nail down."

While the data might not be available to verify it, it seems clear to me: nature rarely demands immediate responses from you to its incessant emails, calls, and texts. 

This brings me to what seems like one ironic flaw in the study, which the researchers have acknowledged, and that's that it may be a very certain type of person that interrupts their time in a park to tweet.

I imagine if you did sentiment analysis on people who left their phone at the office while they went for a stroll in the park, the happiness boost would be through the roof.