Another inconvenient truth – 2012 US tornado count well below normal

P. Solar says: December 1, 2012 at 1:05 am
Just the facts says: Can you offer any data sources that show a significant increase in Tropical Cyclone frequency, strength, season, etc.?
http://i49.tinypic.com/xbfqtw.png
This is basically similar to the NOAA US _landfalling_ hurricanes plot but shows the link to North Atlantic SST. It shows the same thing as Ryan Maue’s plots but on a broader time-scale.
David Jones says: December 1, 2012 at 10:14 am
Do you actually believe that in 1860-70 there was a global network of observers recording cyclones, by whatever name called and calculating the ACE for each year?
According to NOAA;

“ACE” = Accumulated Cyclone Energy – An index that combines the numbers of systems, how long they existed and how intense they became. It is calculated by squaring the maximum sustained surface wind in the system every six hours and summing it up for the season. It is expressed in 104 kt2

The first “flight into a hurricane’s eye” didn’t occur until July 27, 1943;
http://www.af.mil/information/heritage/spotlight.asp?id=123224413
and it was only in the last few decades that we’ve built an impressive fleet of hurricane hunters:
http://www.nasa.gov/vision/earth/lookingatearth/hurricane_aircraft.html
Why should we have any confidence in Accumulated Cyclone Energy estimates prior to the development of accurate measurement capabilities?

P. Solar says: December 2, 2012 at 1:23 am
Define “accurate”.
“the condition or quality of being true, correct, or exact; freedom from error or defect; precision or exactness; correctness. ”
http://dictionary.reference.com/browse/accuracy
Sure. recent measurements are more accurate. That does not mean the rest of the record has to be totally ignored. The only real deviation of the two variables in the 20th century was the WWII period, when under-sampling of tropical zone is obvious and well documented. [Vecchi and Knutson 2008,2011]
Per “A REANALYSIS OF THE 1944-1953 ATLANTIC HURRICANE SEASONS-THE FIRST DECADE OF AIRCRAFT RECONNAISSANCE”, Andrew B. Hagen, UNIVERSITY OF MIAMI, Thesis, 2010:

“The main historical archive of all tropical storms and hurricanes in the North Atlantic Ocean, Caribbean Sea, and Gulf of Mexico from 1851-present is known as HURDAT. This official database of historical Atlantic tropical cyclones (TCs) is maintained by the National Hurricane Center (NHC). The original database of 6-hourly tropical cyclone positions and intensities was assembled in the 1960s in support of the Apollo space program to help provide statistical TC track forecasting guidance (Landsea et al. 2008; Jarvinen et al. 1984; Neumann, personal communication).”
“The accuracy of the HURDAT database is important to many; however, the original database contains many systematic biases and random errors (Landsea et al. 2008). Therefore, a reanalysis of the HURDAT database is necessary. The Atlantic Hurricane Reanalysis Project (AHRP) is an ongoing effort to correct the errors in HURDAT, and to provide as accurate of a HURDAT database as is possible with utilization of all available data. For this thesis, HURDAT is reanalyzed for the period 1944-1953, the first decade of the “aircraft reconnaissance era.” The track and intensity of each existing tropical cyclone in HURDAT is reassessed, and previously unrecognized tropical cyclones are noticed, analyzed, and recommended to the National Hurricane Center Best Track Change Committee (NHCBTCC) for inclusion into HURDAT (existing TCs may be removed from the database as well if analyses indicate evidence that no tropical storm existed). Changes to the number of tropical storms, hurricanes, major hurricanes, accumulated cyclone energy (ACE), and U.S. landfalling hurricanes are recommended for most of the years of the decade studied. An error analysis for the decade is also provided. It is noted that all changes to HURDAT mentioned in this thesis are preliminary and have not yet been approved by the NHCBTCC.”
“Hundreds of track and intensity changes to HURDAT are recommended to the NHCBTCC. Although a significant percentage of these recommendations call for major track and intensity alterations, the overwhelming majority of the recommendations are for minor revisions to HURDAT. However, there were numerous cases for which no changes or minor changes were analyzed due to a lack of available observations since changes to HURDAT cannot be made unless there is enough evidence to make a change. These cases likely contain errors larger than the average error estimates in HURDAT for the decade.”
“This research suggests that for many cases, the intensities listed in HURDAT (at least through 1953, and likely beyond that year) are not nearly as reliable as intensity estimates today.” http://www.aoml.noaa.gov/hrd/hurdat/ahagenF10.pdf

Sure. recent measurements are more accurate. That does not mean the rest of the record has to be totally ignored. The only real deviation of the two variables in the 20th century was the WWII period, when under-sampling of tropical zone is obvious and well documented. [Vecchi and Knutson 2008,2011]
Not ignored, but certainly looked very skeptically. The magnitude of the recent increase you cite in the data could be an “artifact of recent technological advances and better observational capabilities.” ie. recent:

studies, such as Landsea (2007) and Landsea et al. (2010) show that recent technological advances and improved observational capabilities have allowed better detection of TCs. Although the two latter studies focus mainly on TC frequency instead of intensity, the main concept from those studies can be applied here. The observational network during the late 1940s was not as complete as it is today, and better technological advances for monitoring TCs (satellites- geostationary, polar orbiting, microwave, scatterometer; dense coastal radar network; dropsondes, SFMR, and better aircraft radars, etc.) were invented after the late 1940s. These improvements in technology and observational capabilities with time are nicely illustrated by McAdie et al. (2009) and are depicted in Figure 2. http://www.aoml.noaa.gov/hrd/hurdat/ahagenF10.pdf

There are also issues with the SST record which has had of a lot of questionable “corrections” applied but one of the things this comparison does in showing such close correlation , even on shorter time-scales, is it gives a bit more confidence that there is actually some clear climate information in there despite all the data collection issues.
I am not sure that a correlation between two erroneous data sets, with lots of “corrections” applied, should instill any confidence in the accuracy of either.
I’d actually have a bit more confidence in recent ACE calculations than in recent SST which has been subject to constant manipulation.
I agree in the sense that ACE measurement capabilities probably improved faster than our SST measurement capabilities, i.e.:

Prior to the 1980s measurements of sea surface temperature were derived from instruments on shorelines, ships and buoys. The first automated method of gathering sst was by measuring water flowing through the input ports of ocean faring ships. While this method obtained a significant quantity of useful SST data there were some shortcomings. The depth of the input ports of different ships can vary greatly from ship to ship. In a stratified ocean these different depths can have different temperatures. This method also resulted in rigorous sampling along major shipping routes but a dearth of information about the vast majority of the world’s oceans.
Since the 1980’s most of the information about global SST has come from satellite observations. Instruments like the Moderate Resolution Imaging Spectroradiometer on board (MODIS) onboard NASA’s Terra and Aqua satellites orbit the Earth approximately 14 times per day, enabling it to gathering more SST data in 3 months than all other combined SST measurements taken before the advent of satellites. http://podaac.jpl.nasa.gov/SeaSurfaceTemperature

Prior to the satellite era, I am not sure that we should place any confidence in the accuracy of the SST data.
Everyone has to make their own choice of what they chose to accept in all this mess but I think it’s hard to refute the clear linkage between sea temperature and ACE. It is actually pretty much accepted meteorology as to where hurricanes get their energy.
Not arguing that there is a linkage between sea temperature and ACE, but I am very skeptical of the veracity of both data sets.