Do you see the gulf stream waters staying warmer than usual as a factor of stronger tropical systems affecting the northern east coast? The sea surface temperature response to global warming is a key question. We might expect that as ocean temperatures warm at higher latitudes more tropical storms could persist farther north. However, the strength of shearing winds in the atmosphere is also critical. The relative influence of increasing ocean temperatures and changes in shear is a key area of current research and there is not a definitive understanding currently.
I still don't understand the origin of the low pressure. And are you saying that high pressure somehow presses down on the oceans, normally?
Can super storms like this generate low frequency seismic waves or pressure pulse that trigger seismic activity locally and remotely?
John Bailo and Pmagn: The storm surge is a result of the high winds and low pressure. The exact orientation of the storm track as it makes landfall is critical for where the peak surge occurs. In fact, Hurricane Katrina could have been much more damaging, but the peak surge was not centered on the most populated area.
Good points about ocean warmer farther north and Gulf Stream closer to coast; mo' research needed #sciamchat
Markfischetti: We would usually see a clockwise storm track in the northern hemisphere due to the Earth's rotation, and the jet stream (moving west to east) ‘steering' toward the west is a big part of what has made this event so rare. The effect of global warming on this sort of co-occurrence is essentially unstudied.
John Bailo: Here's one link that helps explain the low pressure and Arctic sea ice conditions http://bit.ly/KxgaG4 #sciam
At this stage, my view is that the only scientifically defensible statement is that variability is the main cause. THAT SAID, there is strong evidence that when such a storm occurs, global warming will increase the odds of high storm surge and heavy precipitation.
It seems that our abilities to predict weather are well in hand. As these storms occur outside of the norms, will they be harder to predict?
In_cue36: The forecasts for the direction, intensity and location of landfall were clear for the past several days. Within a few days the models have high accuracy, in part because we have a rich observing system, in part because we understand the short-term physics well. Without satellite observations and very brave hurricane hunters, predictions would be much less accurate.
Sue Ann Bowling
So far the prediction on this one has been astonishingly good.
Sue Ann Bowling: Yes, prediction is a key component of avoiding disaster. Then how people respond to the predictions/warming also plays a key role. In the case of both this storm and Katrina, the predictions were accurate days in advance.
Some models predict that as water temps rise during the century so will wind shear hindering development. However, the systems that do develop will be more massive, but this just doesn't seem to be the case.
Josue Viv: Both global warming and variability are playing a role....
Thanks everyone we are about finished up here. Stay tuned for further chats on Sandy.
Thanks especially to Dr. Noah Diffenbaugh for his expertise and for well-informed answers to our questions.