ESRL/PSD Seminar Series

The Effect of Peaks in the Solar Decadal Oscillation on Atmosphere and Ocean in the Pacific Region (Note: Change of title)

Harry van Loon, NCAR


During 14 peaks in the Decadal Solar Oscillation since 1860 the mean reponse of the atmosphere and ocean in the Pacific region during northern winter to the solar forcing was as follows: The process took place as a strengthening and meridional displacement of the Intertropical Convergence Zone in the Northern Hemisphere and of the South Pacific Convergence Zone, with increased rainfall in these Zones and strengthening of the SE-trades. Consequently upwelling of cooler water in the equatorial belt increased and the dry zone strengthened and extended westwards. The Hadley circulation weakened and the Walker circulation strengthened; and associated positive sea-level pressure anomalies were found in the Gulf of Alaska. The process appears as an enhancement of the climatological mean, has traits in common with Cold Events in the Southern Oscillation, but is far from as pronounced. It is the preferred response to solar forcing at its decadal peaks. In all other years the region is not constrained by a strong solar influence, and the circulation can then vary from Warm to Cold Events in the Southern Oscillation. The accompanying signal in the stratosphere is discussed.

DSRC Multipurpose Room (GC402)
Wednesday, 20 June 2007
2:00 pm Refreshments at 1:50 pm

SECURITY: If you are coming from outside the NOAA campus, please be advised that you will need an on-site sponsor. Please contact that person in advance of the seminar to be put on the list and allow 10 minutes extra on the day of the seminar. Please contact Joe Barsugli (303-497-6042) or Lucia Harrop (303-497-6188) at least a day before the seminar if you have any questions.