SEMINAR: AOML Seminar - November 14, 2011 - Dr. Aixue Hu - “The potential influence of the land-based ice loss on MOC and global climate”

["Aoml.Receptionist" <Aoml.Receptionist@noaa.gov>]

AOML Seminar

 

DATE:               Monday, November 14, 2011

 TIME:               10:30 a.m.  a.m. – refreshments at

        10:15 a.m.

Location:    AOML First Floor Conference

                          Room

SPEAKER:        Dr.  Aixue Hu 

                          National Center for Atmospheric Research 

TITLE:              “The potential influence of the 

                          land-based  ice loss on MOC 

                          and  global climate”

ABSTRACT: Observed evidence indicates a net loss of the global land-based ice and a rising of the global sea level. 
It is not clear how this loss of land-based ice could affect the global climate in the future except the sea level. 
Here, we use the National Center for Atmospheric Research Community Climate System Model version 3 to evaluate the 
potential influence of a shrinking land-based ice on the Atlantic meridional overturning circulation (MOC) and the surface 
limate in the next two centuries under the IPCC A1B scenario with prescribed rates of Greenland Ice Sheet, Western Antarctic 
Ice Sheet, and the mountain glacier and ice cap melting. Our results show that the MOC, in general, is only sensitive to the 
discharge of freshwater directly into the North Atlantic in the next two centuries. The loss of the Western Antarctic
For the Greenland Ice loss, a low rate of Greenland melting will not significantly alter the MOC, but a moderate to high rate 
of Greenland melting does make the MOC weaken further. This further weakened MOC will not make the global climate in the next 
two centuries cooler than in the late 20th century, but will lessen the warming, especially in the northern high latitudes. 
Moreover, the sea level changes due to steric effect and ocean dynamics could potentially aggravate the sea level problem 
ear the northeast North America coast and the islands in the western Pacific region. On the other hand, in comparison to the 
simulation without the inclusion of the land ice runoff, the projected precipitation increase in the North America is significantly 
reduced, and even becomes a net reduction in the cases that the AMOC further slows down when the land ice runoff is included.