Warming Rate in the US Slowed during the Recent Warming Period

I’m quiet agree with you and want to add that we have found the evidence that in general observed in the past century warming was not continuous but step function. There were two climate shifts in 1925/1926 and 1987/1988 years. During each shift mean temperatures in tropics/north middle altitudes increased by about 0.28/0.36 °C. Other temperature anomalies are explained by natural variability. And the existence of these shifts also masked by natural variability. This hypothesis allows to develop very simple linear regression models which explain main features of observed in the past century temperature anomalies. Now we are working on publication them in peer-review journal and are interested in opinions and replies.
There are two remarkable moments. The first one is that linear regression coefficients can be fitted by the small part of data (from 1900 till 1940 for example) and quite well reproduce the whole period from 1900 till now. The second one is that good quality of reproduction is achieved by using only three factors (ENSO/PDO, volcanoes and shifts for tropics/northern middle altitudes).
A draft of manuscript can be downloaded by link
http://vixra.org/abs/1212.0172.
If you are interested I can send all the data and calculations.
if you have any ideas we can unite our effort

So, is this the data after value has been added? It is hard to believe that 2012 was at all warmer than 1938.

Time to remind those Newspapers in California that the extreme cold snap is caused by Global warming! LOL

lgl, that trend looks awfully flat? Is there a post somewhere that it goes with?

When I look at the Contiguous US Land Surface air Temperature graph that Bob provided , one of the common variables that strikes me is that warm Atlantic SST as measured by AMO was present during most of the major drought and warm spells ,namely 1931-1939,1953-1956,and again 1995-2012 . The paper KEY ROLE OF THE ATLANTIC MULTIDECADAL OSCILLATION IN THE 20TH CENTURY DROUGHT AND WET PERIODS OVER THE GREAT PLAINS by Sumaant Nigam et al.2011 speaks to this in more detail. The impact is the greatest in the midwest, southwest and Rocky mountains /Great basin areas. The presence of more colder water along the Pacific East coast than in the western and central Pacific coast which happened also during the positive AMO periods also seems to be a contributor. Mc Cabe et al wrote about this same topic in their paper PACIFIC AND ATLANTIC OCEAN INFLUENCES ON MULTIDECADAL DROUGHT FREQUENCY IN THE UNITED STATES .[2004] Blaming the 2o12 US warm year entirely on global warming is wrong . This may be a regional short term event that cannot be lifted onto the global stage and blamed on man generated greenhouse gases because globally the temperatures have been actually flat and most recently decliningg over the last 10 years . We just cannot blame every regional climate event on global warming. Just look at the spike in 1921 or those in the 1930’s in the US . These were local short term events that I am sure have happened before in this part of the world and will happen again.

Here are some concluding remarks from the authors of the first paper noted above [Sumant Nigam et al]
“We find Atlantic SSTs, tropical and extratropical, to be particularly
influential; often, more than the Pacific ones, and more than
in previous analyses, especially from the SST‐forced atmospheric models: AMO is the dominant contributor (∼50% of
the signal) in the Dust Bowl spring drought and in the 1980s
fall wetness (i.e., in 2 of the 4 episodes) while the Atlantic
Nino is in another (Dust Bowl summer).
Atlantic is more influential than the Pacific in 3 of the
4 reconstructed episodes
The AMO’s influence on continental hydroclimate is
provided circulation context from analysis of low‐level flow
and the column stationary moisture flux, both obtained from
NOAA’s 20th Century Reanalysis; the modulation of
moisture transport was consequential. A hypothesis for how
the AMO atmospheric circulation anomalies are generated
from AMO SSTs is proposed.
The Atlantic SSTs evidently exert a profound influence
on Great Plains hydroclimate on decadal timescales, especially in the transition seasons; an influence not represented
in the SST‐forced dynamical models of the atmosphere. For
instance, Schubert et al. [2009] find a cold‐Pacific and neutral
Atlantic to be significantly more influential for US droughts
than a neutral‐Pacific and warm‐Atlantic (PcAn
PnAw in
their drought modeling experiment nomenclature).
Our analysis suggests that the La Nina–US drought
paradigm, operative on interannual time scales, has been
conferred excessive relevance on decadal time scales in the
recent literature, in part, because dynamical models of the
atmosphere are unable to represent the influence of Atlantic
SSTs on Great Plains hydroclimate. Regardless, the present
analysis is encouraging for the investigation of SST‐based
decadal drought/wetness predictability.”

English climatologist Hubert H. Lamb [1]. Lamb, who founded the UK Climate Research Unit (CRU) in 1971, saw the peak of the warming period from 1000 to 1300, yet a negative PDO was evident at this time.
http://i446.photobucket.com/albums/qq187/bobclive/800px-PDO1000yrsvg_zpsa0c71d41.png
There was though a high sunspot count.
http://i446.photobucket.com/albums/qq187/bobclive/sunspots_zpsbbbb4912.jpg

Bob Tisdale says:
“Not sure what you’re trying to show with the graph, but I only deal with satellite-era sea surface temperatures. That’s the time period the IPCC says that only greenhouse gases can explain the warming.”
Dear Bob, you can easily extend your analysis to 1900. For example, adequate reconstruction of HadSST2 temperatures of tropics (30S-30N) by linear regression could be achieved by consideration only 3 factors – ENSO (Nino34 index from HadSST2), volcanoes (global Optical Thickness at 550 nm, from NASA/GISS) and climate regime shifts in 1925/1926 and 1987.
Calculations are in this simple Excel file:
https://www.dropbox.com/s/tko1zqal92mmwkp/Tropical%20SST%20with%20shift.xls
Correlation coefficient for monthly mean time series – 0.86! Another remarkable moment is that coefficients of linear regression can be fitted by small amount of data – for example, from 1910 till 1940, for adequate reconstruction of the whole period.
Reality of climate regime shifts in 1925/1926 and 1987 is proved by many independent studies that are summarized in our preprint: http://vixra.org/abs/1212.0172

Arbitrarily choosing the start and end dates of the analyses along with comparing time periods of different length invalidates the conclusions of this post. There are far more statistically robust methods that could have been used. One wonders why they weren’t.

Surely this is a joke?
Your trend for the early period is computed from either 18 or 16 years (the text and figures disagree), but you compute trends for the late period for a longer year.
If you’d listened to any of the arguments about recent changes in global temperature you would know that noise int he temperature record can have a big effect on short period trends, so it’s not surprising that you can find a short period early in the record that has a higher trend than a long period late in the record.
That is just what you’d expect from a basic understanding of statistics. It’s why sample sizes are important.
Why don’t you do some proper trend analysis and then see what that says?

I’m sorry Bob you draw a couple of simplistic lines through arbitrary choose points and come to a conclusion, is that joke??? Is that what passes for “analysis” these days, if I were you I’d ask to remove this post as it really undermines your credibility.

misfratz says:January 15, 2013 at 11:22 pm
Surely this is a joke?
The joke is the reduced rate of warming in the second sample that is Thermageddonally® charged with CO2.
MorningGuy, look up linear regression.

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