[Vision2020] National Center for Atmospheric Research: Record Daily High Temperatures Far Outpace Record Lows In US

[Paul Rumelhart]

A quote from the article:

"If the climate weren't changing, you would expect the number of 
temperature <http://www.physorg.com/tags/temperature/> records to 
diminish significantly over time," says Claudia Tebaldi, a statistician 
with Climate Central who is one of the paper's co-authors. "As you 
measure the high and low daily temperatures each year, it normally 
becomes more difficult to break a record after a number of years. But as 
the average temperatures continue to rise this century, we will keep 
setting more record highs."

They don't actually say that the number of temperatures is actually 
diminishing over time or not.  Since they bring up as an expected 
consequence of climate change, you would think they would declare 
whether or not it was diminishing.

Another quote from the article:

The study also found that the two-to-one ratio across the country as a 
whole could be attributed more to a comparatively small number of record 
lows than to a large number of record highs. This indicates that much of 
the nation's warming is occurring at night, when temperatures are 
dipping less often to record lows. This finding is consistent with years 
of climate model research showing that higher overnight lows should be 
expected with climate change.


This would lead me to believe that the number of record highs and lows 
is diminishing over time, as you would expect.

Would it have killed them to provide the simple numbers of record highs 
and lows next to the by-decade ratios?  I'd rather see more information 
in a graph than a cute picture of the US and large 3D bars.

If I get more time to crunch data, I'll see if I can provide a similar 
global graph, albeit using data that is aggregated at the monthly level 
rather than the daily level, since that's all I have access to.  I doubt 
I'll have anything in the near future, since I'm really busy at work and 
I have to write more code to limit the stations to those that existed in 
1950 and to do the counts of record highs and lows.  Not to mention that 
I'm still working on getting monthly graphs and trying to extract data 
for Moscow to see what that looks like.

Paul

Ted Moffett wrote:
> http://www.physorg.com/news177254019.html
>  
> http://www.ucar.edu/news/releases/2009/maxmin.jsp
>  
> temps <http://www.ucar.edu/news/releases/2009/images/temps_2.jpg>
>
> This graphic shows the ratio of record daily highs to record daily 
> lows observed at about 1,800 weather stations in the 48 contiguous 
> United States from January 1950 through September 2009. Each bar shows 
> the proportion of record highs (red) to record lows (blue) for each 
> decade. The 1960s and 1970s saw slightly more record daily lows than 
> highs, but in the last 30 years record highs have increasingly 
> predominated, with the ratio now about two-to-one for the 48 states as 
> a whole. [ENLARGE] 
> <http://www.ucar.edu/news/releases/2009/images/temps_2.jpg> (©UCAR, 
> graphic by Mike Shibao.) News media terms of use* 
> <http://www.ucar.edu/news/releases/2009/maxmin.jsp#>
>
> -------------------------
>
> More records ahead
>
> In addition to surveying actual temperatures in recent decades, Meehl 
> and his co-authors turned to a sophisticated computer model of global 
> climate to determine how record high and low temperatures are likely 
> to change during the course of this century.
>
> The modeling results indicate that if nations continue to increase 
> their emissions of greenhouse gases in a "business as usual" scenario, 
> the U.S. ratio of daily record high to record low temperatures would 
> increase to about 20-to-1 by mid-century and 50-to-1 by 2100. The 
> mid-century ratio could be much higher if emissions rose at an even 
> greater pace, or it could be about 8-to-1 if emissions were reduced 
> significantly, the model showed.
>
> ------------------------------------------
>
> Vision2020 Post: Ted Moffett
>
> ------------------------------------------------------------------------
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