NOAA shows ‘the pause’ in the U.S. surface temperature record over nearly a decade
Posted on June 7, 2014 by Anthony Watts
 After years of waiting, NOAA has finally made a monthly dataset on the U.S. Climate Reference Network available in a user friendly way via their recent web page upgrades. This data is from state-of-the-art ultra-reliable triple redundant weather stations placed on pristine environments. As a result, these temperature data need none of the adjustments that plague the older surface temperature networks, such as USHCN and GHCN, which have been heavily adjusted to attempt corrections for a wide variety of biases. Using NOAA’s own USCRN data, which eliminates all of the squabbles over the accuracy of and the adjustment of temperature data, we can get a clear plot of pristine surface data. It could be argued that a decade is too short and that the data is way too volatile for a reasonable trend analysis, but let’s see if the new state-of-the-art USCRN data shows warming.
A series of graphs from NOAA follow, plotting Average, Maximum, and Minimum surface temperature follow, along with trend analysis and original source data to allow interested parties to replicate it.
First, some background on this new temperature monitoring network, from the network home page:
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As you can see, every issue and contingency has been thought out and dealt with. Essentially, the U.S. Climate Reference Network is the best climate monitoring network in the world, and without peer. Besides being in pristine environments away from man-made influences such as urbanization and resultant UHI issues, it is also routinely calibrated and maintained, something that cannot be said for the U.S. Historical Climate Network (USHCN), which is a mishmash of varying equipment (alcohol thermometers in wooden boxes, electronic thermometers on posts, airport ASOS stations placed for aviation), compromised locations, and a near complete lack of regular thermometer testing and calibration.
Having established its equipment homogenity, state of the art triple redundant instrumentation, lack of environmental bias, long term accuracy, calibration, and lack of need for any adjustments, let us examine the data produced for the last decade by the U.S. Climate Reference Network.
First, from NOAA’s own plotter at the National Climatic Data Center in Asheville, NC, this plot they make available to the public showing average temperature for the Contiguous United States by month:
Source: =uscrn¶meter=anom-tavg&time_scale=p12&begyear=2004&endyear=2014&month=12]NCDC National Temperature Index time series plotter
To eliminate any claims of “cherry picking” the time period, I selected the range to be from 2004 through 2014, and as you can see, no data exists prior to January 2005. NOAA/NCDC does not make any data from the USCRN available prior to 2005, because there were not enough stations in place yet to be representative of the Contiguous United States. What you see is the USCRN data record in its entirety, with no adjustments, no start and end date selections, and no truncation. The only thing that has been done to the monthly average data is gridding the USCRN stations, so that the plot is representative of the Contiguous United States.
Helpfully, the data for that plot is also made available on the same web page. Here is a comma separated value (CSV) Excel workbook file for that plot above from NOAA:
USCRN_Avg_Temp_time-series (Excel Data File)
Because NOAA/NCDC offers no trend line generation in their user interface, from that NOAA provided data file, I have plotted the data, and provided a linear trend line using a least-squares curve fitting procedure which is a function in the DPlot program that I use.
Not only is there a pause in the posited temperature rise from man-made global warming, but a clearly evident slight cooling trend in the U.S. Average Temperature over nearly the last decade:
We’ve had a couple of heat waves and we’ve had some cool spells too. In other words, weather.
The =uscrn¶meter=anom-tavg&time_scale=p12&begyear=2004&endyear=2014&month=12]NCDC National Temperature Index time series plotter also makes maximum and minimum temperature data plots available. I have downloaded their plots and data, supplemented with my own plots to show the trend line. Read on.
NOAA/NCDC plot of maximum temperature:
 Source of the plot =uscrn¶meter=anom-tmax&time_scale=p12&begyear=2004&endyear=2014&month=12]here.
Data from the plot: USCRN_Max_Temp_time-series (Excel Data File)*
My plot with trend line:
As seen by the trend line, there is a slight cooling in maximum temperatures in the Contiguous United States, suggesting that heat wave events (seen in 2006 and 2012) were isolated weather incidents, and not part of the near decadal trend.
NOAA/NCDC plot of minimum temperature:
Source of the plot =uscrn¶meter=anom-tmin&time_scale=p12&begyear=2004&endyear=2014&month=12]here.
USCRN_Min_Temp_time-series (Excel Data File)*
The cold winter of 2013 and 2014 is clearly evident in the plot above, with Feb 2013 being -3.04°F nationally.
My plot with trend line:
*I should note that NOAA/NCDC’s links to XML, CSV, and JSON files on their =uscrn¶meter=anom-tmin&time_scale=p12&begyear=2004&endyear=2014&month=12]plotter page only provide the average temperature data set, and not the maximum and minimum temperature data sets, which may be a web page bug. However, the correct data appears in the HTML table on display below the plot, and I imported that into Excel and saved it as a data file in workbook format.The trend line illustrates a cooling trend in the minimum temperatures across the Contiguous United States for nearly a decade. There is some endpoint sensitivity in the plots going on, which is to be expected and can’t be helped, but the fact that all three temperature sets, average, max, and min show a cooling trend is notable.
It is clear there has been no rise in U.S. surface air temperature in the past decade. In fact, a slight cooling is demonstrated, though given the short time frame for the dataset, about all we can do is note it, and watch it to see if it persists.
Likewise, there does not seem to have been any statistically significant warming in the contiguous U.S. since start of the new USCRN data, using the average, maximum or minimum temperature data.
I asked three people who are well versed in data plotting and analysis to review this post before I published it, one, Willis Eschenbach, added his own graph as part of the review feedback, a trend analysis with error bars, shown below.
While we can’t say there has been a statistically significant cooling trend, even though the slope of the trend is downward, we also can’t say there’s been a statistically significant warming trend either.
What we can say, is that this is just one more dataset that indicates a pause in the posited rise of temperature in the Contiguous United States for nearly a decade, as measured by the best surface temperature monitoring network in the world. It is unfortunate that we don’t have similar systems distributed worldwide.
http://wattsupwiththat.com/2014/06/07/noaa-shows-the-pause-in-the-u-s-surface-temperature-record-over-nearly-a-decade/ |
