Normally folks mark March 21st as the first day of spring, also known as the vernal equinox.
But spring is already appearing down the coast of California, Nevada, Colorado, and central Kansas, as well as in Missouri, Illinois, Indiana, and Ohio. The east coast including the Virginias and Philadelphia are also seeing an early onset of spring this year.
Scientists have known for years and years that climate change is advancing the start of spring in the United States. But how do they figure out the start of spring?
Maps & Models
The USGS-led USA National Phenology Network created maps to show just how far ahead of schedule spring is arriving all over the nation.
To create the maps and predict the date of arrival, researchers use climate change indicators called Spring Indices. These tools detect when enough heat has accumulated to cause blooming and leafing in plants. The plants that they use for their research are lilacs and honeysuckles because of their temperature sensitivity.
Information was also gathered from the National Oceanic and Atmospheric Administration. The NOAA has nationwide heat and temperature data that is useful in creating the maps. After researchers apply the plant models to recent weather data, they are able to create maps of leaf emergence for the plant species.
The maps are drawn on a national level and are based on data gathered across the country. These daily maps are then compared to historical maps to find out how different this year is when looking at a long-term average.
This data helps to map out unusually early spring patterns in the United States.
Issues With Early Spring
Although the thought of an early spring may sound nice, it comes along with its concerns.
Flowers blooming early can disrupt the harmony between wildflowers and the small species that feed on and pollinate the flowers.
If these early, mild temperatures are followed by a sudden freezing spell, the buds and blooms can be killed by frost. This would also affect the plant's flowering and fruiting cycles for the rest of the year. Also, early snowmelt and increasing temperatures can cause summertime droughts and forest fires.
The early onset of spring also affects the planning and management of issues that can affect the country’s economy as well as our society. Changes in seasons can disrupt businesses that depend on outdoor recreational activities and impact fishing and hunting seasons.
Finally, changing weather patterns can affect human health as well. It can bring disease carriers such as ticks and mosquitos, and a prolonged pollen season.
