Havsytans höjning 2013-04-24
Forskning om Antarktis igen
“Over the past century, most of Antarctica has not undergone the fairly dramatic warming that has affected the rest of the globe,” says NCAR scientist Andrew Monaghan, the lead author of a study published on 5 April in Geophysical Research Letters. Monaghan’s coauthors were David Schneider (NCAR) and David Bromwich (Ohio State University).Temperaturtrender 35 år tillbaks i tiden. Modellstudierna har förutsagt en större uppvärming än vad som mätts upp. ”The GRL paper suggests that warming in Antarctica over the next century could offset that by about 5 cm (2 in) if the continent warms by 5.4°F (3°C), as computer models have indicated. The reason is that the warmer air over Antarctica would hold more moisture and generate more snowfall, thereby locking up additional water in the continent’s ice sheets”.
Alltså ännu en forskargrupp som tror att Antarktis bidrag till havsytans förändring blir en sänkning. Även om 5 cm inte är lika högt som ISSI:s beräkning på 30 cm sänkning fram till 2300.
Orsaken till skillnaden sägs vara:” The error appeared to be caused by models overestimating the amount of water vapor in the Antarctic atmosphere, the new study concludes. The reason may have to do with the cold Antarctic atmosphere handling moisture differently than the atmosphere over warmer regions.”
Dessutom kopplas nu smältningen på Västantarktiska halvön till de klimatsvängningar i Stilla Havet som Kallas El Nino.