Storm Surge

One of the difficulties studying changes in the frequency and intensity of cyclones is that the record of past storms is inhomogeneous, due to changes in observational capabilities and how storms have been measured and recorded. But a new paper by Grinsted et al. has found evidence of past cyclone occurrence in the western Atlantic which impacted the U.S. east coast, evidence which is homogenous over a period of nearly a century, by studying not storm records, but surges in sea level recorded at tide gauge stations.

Sea unLevel

Sea level is by no means “level.” Not only are there small changes in the geoid (the gravitational equipotential surface), the sea itself does not conform to the geoid because of winds and currents, tides and storms. These geographical variations are in addition to the constant fluctuations caused by the exchange of water between land, oceans, ice, and atmosphere, and of course the changes wrought by global warming.

NOAA’s Laboratory for Satellite Altimetry has sea level time series derived from satellite data, not just for the globe, but for a number of different regions around the globe. Let’s take a look.

Hurricane Sandy

It has once again strengthened to hurricane force. Expected landfall is New Jersey.

Forewarned is forearmed.

More on David Rose’s nonsense

There’s an excellent post on Skeptical Science about the latest David Rose/Judith Curry nonsense. My favorite part is this graph (you may have to click the graph to see the animation):

Excellent!

Winter Cooling?

It was mentioned in recent discussion that Cohen et al. (2012) found recent winter cooling in much of the boreal (northern but not necessarily Arctic) northern hemisphere. In fact, here’s their key graph for that particular question:

Colors show the wintertime temperature trend from 1988 through 2010, with red indicating warming while blue indicates cooling, based on the HadCRUT3 gridded temperature data set. They note cooling in northern Europe, Russia, and eastern North America.

Temperature “analysis” by David Rose doesn’t smell so sweet

Not long ago, the Hadley Centre/Climate Research Unit in the U.K. released their new “HadCRUT4” global temperature data set. That prompted David Rose of the Daily Mail to claim that “Global warming stopped 16 years ago.”

Arctic Winter

It was pointed out in comments recently that Wang et al. (2012) found a cooling trend during the winter season in the Arctic (defined as the area from latitude 60N to the pole) from 1982 through 2004, using estimates of surface skin temperature from AVHRR (Advanced Very-High Resolution Radiometer) instruments aboard satellites.

Arctic Amplification

Various processes, including albedo change (the change in reflectivity when ice and snow are replaced by open land or ocean), amplify the warming which is observed in the Arctic. Yet the situation is complicated. Cloud cover can change, which also affects reflectivity and can reduce or increase Arctic warming. Atmospheric patterns can likewise change, as can the state of the atmosphere in general. Overall, although we know that the Arctic is warming faster than the planet as a whole, how great this amplification will be in the future remains uncertain.

Your Servant

Every mathematician develops his own preferences for notation. This is necessary because there are often (I’m tempted to say “usually”) many notations for the same concept.

CO2 Velocity

As I mentioned in an earlier post, I recently modified my smoothing program so that it would record not only the estimated smoothed value, but the estimated smooothed velocity (rate of change) as well. I’m always a little leery of a new analysis method, there could be some unanticipated quirk of its behavior, but let’s apply it anyway to estimate the momentary rate of change (the velocity) of CO₂ on about a 5-year time scale.