Monday, 15 January 2007
The search for ocean influences on midlatitude cyclones
Exhibit Hall C (Henry B. Gonzalez Convention Center)
Midlatitude SST anomalies are relatively long lived and their local impact, if it exists at all, is generally thought to project onto slow variations of the atmosphere. However, two streams of research have an important bearing on the question of how such an upward influence might occur: the atmosphere appears to respond differently according to season and midlatitude eddies appear to play a role both in initiating and maintaining such variations. Thus, while it may be useful to quantify the role of SST anomalies in terms of their impact on the mean flow, there remains the possibility that SST anomalies are also indicative of the net role of surface heat and moisture fluxes in midlatitude cyclones. We search for evidence of this by organizing strong cyclones according to a seasonal phenomenon that sometimes occurs over the North Pacific Ocean, called the midwinter storm track suppression. Although the North Atlantic storm track does not exhibit a midwinter suppression, possible similarities to North Pacific cyclones are briefly explored as well.