Research suggests autumn is ending later in the northern hemisphere

http://www.eurekalert.org/pub_releases/2014-03/uos-rsa032814.php

PUBLIC RELEASE DATE: 28-Mar-2014

Contact: Peter Franklin
University of Southampton

Research suggests autumn is ending later in the northern hemisphere

A study by the University of Southampton suggests that on average the end of Autumn is taking place later in the year and Spring is starting slightly earlier.

A team of researchers examined satellite imagery covering the northern hemisphere over a 25 year period (1982 - 2006), and looked for any seasonal changes in vegetation by making a measure of its 'greenness'. They examined in detail, at daily intervals, the growth cycle of the vegetation – identifying physical changes such as leaf cover, colour and growth.

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The most pronounced change found by the researchers was in the broad-leaved deciduous and needleleaved deciduous forest groups, showing that Autumn is becoming significantly later. This delay in the signs of Autumn was generally more pronounced than any evidence for an earlier onset of Spring, although there is evidence across the groups that Spring is arriving slightly earlier.

Professor Peter Atkinson comments: "Previous studies have reported trends in the start of Spring and end of Autumn, but we have studied a longer time period and controlled for forest loss and vegetation type, making our study more rigorous and with a greater degree of accuracy.

"Our research shows that even when we control for land cover changes across the globe a changing climate is significantly altering the vegetation growth cycles for certain types of vegetation. Such changes may have consequences for the sustainability of the plants themselves, as well as species which depend on them, and ultimately the climate through changes to the carbon cycle."

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