|Nombre del curso:|Nombre del profesor: |
|Computer Science |Ricardo Hernandez ||Módulo: module 1 |Actividad: |
|Fecha: Aug 26 2010 |Equipo:/ |
Spring Coming Earlier, Study Says
for National Geographic News
January 21, 2009
Tired of winter? Good news: Spring arrives an average of 1.7 days earlier now than it did in the first half of the 20th century, according to anew study.
Summer, fall, and winter are also starting 1.7 days earlier. And there is less of a temperature difference between winter and summer.
The shifts, which are occurring over land (seasonalshifts are different over oceans), appear to stem from as-yet-to-be determined changes in the physics of the Earth's climate system, said Alexander Stine, a graduate student of Earth and planetarysciences at the University of California, Berkeley, and lead author of the study.
The shifts occur at the same time humans are known to be influencing the climate. (Read up on global warming.)
"TheEarth is certainly warming," said Stine, whose findings will be published in tomorrow's issue of the journal Nature. "It would seem reasonable that there's some relationship."