2013 Global Temperatures

[The_Global_Warmer]

The OHC really hasn't changed much closer to the surface over the last decade which reflects the surface temperatures. 

 

Abraham_2013.png

 

 

Its risen enough for the global temp record to be set.

 

This year has had every single month with a negative ONI.

 

Going back to December:  So that is negative the entire year.  And we are still sitting at .59C on GISS and .24C on UAH. 

 

Let's say we get a .60 or .61C on GISS for 2013.  November on CFS is already at .11C.  So far a .66C monthly equivalent.

 

.61C would be .05 below the record.  I think a 2010 like NINO would be .75 to .80C.  A weaker one in the .68 to .72C range.

 

I can't see a weak nino not causing the global temps to be less than .05C more than this year.

 

-0.3

2013

-0.6

-0.6

-0.4

-0.2

-0.2

-0.3

-0.3

-0.3

-0.3

 

 

This graphic shows a much larger change in 2013. 

 

 

[donsutherland1]

It appears June was revised downward again to 0.61C (its initial value was 0.67 and the last previous update was 0.66), and July was revised downward from 0.54 to 0.52...however, March was revised upward from 0.59 to 0.60, February from 0.50 to 0.51, and May from 0.54 to 0.57.

Thanks for this information.

[nflwxman]

I think there is almost no chance of setting the yearly temperature record in 2014 unless a bizarre El Nino develops in late winter and sustains through the summer.

 

Thanks for the GISS information ORH.  I disagree with the statement above though.  The fact that we were sitting between a -0.3 and -0.5 ONI all year with global temperatures around 0.59 suggest that it would not take much to bump into record territory (the record is 0.67).  I think all we need is ONI to be positive for a sustained period of time 8 months or more.  That has not happened since 2009.  Solar is about reaching max.

[ORH_wxman]

Thanks for the GISS information ORH.  I disagree with the statement above though.  The fact that we were sitting between a -0.3 and -0.5 ONI all year with global temperatures around 0.59 suggest that it would not take much to bump into record territory (the record is 0.67).  I think all we need is ONI to be positive for a sustained period of time 8 months or more.  That has not happened since 2009.  Solar is about reaching max.

 

The first part of 2013 was influenced by positive ENSO in the fall of 2012. Solar has about a 2 year lag, so what it is doing right now is irrelevant to 2014.

[nflwxman]

The first part of 2013 was influenced by positive ENSO in the fall of 2012. Solar has about a 2 year lag, so what it is doing right now is irrelevant to 2014.

 

Maybe January was.  If you remove January from the 2013 surface record- you drop the average temperature of the year from 59 to 58.5.  Doesn't really change the initial point.  The vast majority of the year (80%ore more, IMO) has impacted by a negative ONI, which at times has bordered on La Nina territory..  

 

I would imagine the difference between La Nina (-0.5 ONI) and El Nino (0.5) ranges somewhere in the 0.15-0.20 range for global temperatures.  All else being equal.

[ORH_wxman]

Maybe January was.  If you remove January from the 2013 surface record- you drop the average temperature of the year from 59 to 58.5.  Doesn't really change the initial point.  The vast majority of the year (80%ore more, IMO) has impacted by a negative ONI, which at times has bordered on La Nina territory..  

 

I would imagine the difference between La Nina (-0.5 ONI) and El Nino (0.5) ranges somewhere in the 0.15-0.20 range for global temperatures.  All else being equal.

 

 

No, that is way too high. That is roughly the difference between a strong El Nino (greater than 1.5 ONI) and a strong La Nina (less than -1.5 ONI).

 

Also, January 2013 wasn't the only month influenced...we had positive ENSO into November of 2012.

[nflwxman]

There is a new paper that attempts to fill in some of the data gaps of the HadCrut4 dataset.  The abstract is below.

 

 

http://onlinelibrary.wiley.com/doi/10.1002/qj.2297/abstract

 

"Incomplete global coverage is a potential source of bias in global temperature reconstructions if the unsampled regions are not uniformly distributed over the planet's surface. The widely used HadCRUT4 dataset covers on average about 84% of the globe over recent decades, with the unsampled regions being concentrated at the poles and over Africa. Three existing reconstructions with near-global coverage are examined, each suggesting that HadCRUT4 is subject to bias due to its treatment of unobserved regions.

Two alternative approaches for reconstructing global temperatures are explored, one based on an optimal interpolation algorithm and the other a hybrid method incorporating additional information from the satellite temperature record. The methods are validated on the basis of their skill at reconstructing omitted sets of observations. Both methods provide superior results than excluding the unsampled regions, with the hybrid method showing particular skill around the regions where no observations are available.

Temperature trends are compared for the hybrid global temperature reconstruction and the raw HadCRUT4 data. The widely quoted trend since 1997 in the hybrid global reconstruction is two and a half times greater than the corresponding trend in the coverage-biased HadCRUT4 data. Coverage bias causes a cool bias in recent temperatures relative to the late 1990s which increases from around 1998 to the present. Trends starting in 1997 or 1998 are particularly biased with respect to the global trend. The issue is exacerbated by the strong El Niño event of 1997-1998, which also tends to suppress trends starting during those years."

 

 

Edit: I'm surprised this has not been done before- I would imagine a direct measurement from satellite would be a better infill method than what GISS does in just extrapolation. 

 

#thepauseisanillusion

[Bannor]

New paper in the Quarterly Journal of the Royal Meteorological Society:

 

Coverage bias in the HadCRUT4 temperature series and its impact on recent temperature trends

 

http://onlinelibrary.wiley.com/doi/10.1002/qj.2297/abstract

 

 

Abstract:

 

 

Incomplete global coverage is a potential source of bias in global temperature reconstructions if the unsampled regions are not uniformly distributed over the planet's surface. The widely used HadCRUT4 dataset covers on average about 84% of the globe over recent decades, with the unsampled regions being concentrated at the poles and over Africa. Three existing reconstructions with near-global coverage are examined, each suggesting that HadCRUT4 is subject to bias due to its treatment of unobserved regions.

 

Two alternative approaches for reconstructing global temperatures are explored, one based on an optimal interpolation algorithm and the other a hybrid method incorporating additional information from the satellite temperature record. The methods are validated on the basis of their skill at reconstructing omitted sets of observations. Both methods provide superior results than excluding the unsampled regions, with the hybrid method showing particular skill around the regions where no observations are available.

 

Temperature trends are compared for the hybrid global temperature reconstruction and the raw HadCRUT4 data. The widely quoted trend since 1997 in the hybrid global reconstruction is two and a half times greater than the corresponding trend in the coverage-biased HadCRUT4 data. Coverage bias causes a cool bias in recent temperatures relative to the late 1990s which increases from around 1998 to the present. Trends starting in 1997 or 1998 are particularly biased with respect to the global trend. The issue is exacerbated by the strong El Niño event of 1997-1998, which also tends to suppress trends starting during those years.

 

Short explanatory video by authors:

 

http://www.youtube.com/watch?v=GhJR3ywIijo

 

 

Edit: Sorry, didn't see nflwxman had already posted.

[nflwxman]

No, that is way too high. That is roughly the difference between a strong El Nino (greater than 1.5 ONI) and a strong La Nina (less than -1.5 ONI).

 

Also, January 2013 wasn't the only month influenced...we had positive ENSO into November of 2012.

 

Yes, you are correct on that.  That would likely be the difference between a strong El Nino and Strong La Nina- 1998 and 1999 are pretty good examples of that.  The difference was about 0.21 between 1998 and 1999.  But remember, all we need from our current 2013 state is about 0.07 degrees to break an annual record, which is a third of the difference between a strong El Nino and La Nina.

 

Regardless, this is all qualitative.  I'm not saying it will happen- I just don't find it quite as impossible as you without an El Nino. 

[ORH_wxman]

Yes, you are correct on that.  That would likely be the difference between a strong El Nino and Strong La Nina- 1998 and 1999 are pretty good examples of that.  The difference was about 0.21 between 1998 and 1999.  But remember, all we need from our current 2013 state is about 0.07 degrees to break an annual record, which is a third of the difference between a strong El Nino and La Nina.

 

Regardless, this is all qualitative.  I'm not saying it will happen- I just don't find it quite as impossible as you without an El Nino. 

 

 

I can happen if we don't get an El Nino for a long time, but 2014 won't set a record without an El Nino.

[bluewave]

I can happen if we don't get an El Nino for a long time, but 2014 won't set a record without an El Nino.

 

I wonder if 2014 will still struggle to set a record even if El Nino conditions develop sometime during the second half of the year.

It seems like all previous record breaking years had an El Nino present during January which won't be the case in 2014. Maybe we could close in on a statistical tie with 2010 if an El Nino develops by the fall? 2015 may be the

year to watch if the El Nino can close the deal for fall into winter 2015.

[ORH_wxman]

I wonder if 2014 will still struggle to set a record even if El Nino conditions develop sometime during the second half of the year.

It seems like all previous record breaking years had an El Nino present during January which won't be the case in 2014. Maybe we could close in on a statistical tie with 2010 if an El Nino develops by the fall? 2015 may be the

year to watch if the El Nino can close the deal for fall into winter 2015.

 

I think so too, which is why earlier I said that unless we had some bizarre late developing El Nino this winter that maintained itself through summer (very rare for this to happen), 2014 wouldn't break any records.

 

2005 set a record despite being a weak El Nino, though it had the benefit of working off the tail end of the 2002 solar max (using the typical 2-3 year lag) and a general prolonged +PDO regime that extended back to 2002. I would guess that 2015 would need at least a weak El Nino in winter 2014-2015 to set a new record.

[skierinvermont]

I think there is almost no chance of setting the yearly temperature record in 2014 unless a bizarre El Nino develops in late winter and sustains through the summer.

 

While I think it is pretty unlikely I'd still describe it as more than "almost no chance." You can get bizarre years like 2005 which are way warmer than the surrounding years despite a pretty subdued ENSO state. With the solar max, and a probably +AO to start the year, I'd give it a 5 or 10% chance. This year is likely going to be only .06 or .07 from the record on GISS despite negative neutral. A positive neutral year and some luck, and we could break it. Or an early developing Nino in fall. 

[skierinvermont]

 

There is a new paper that attempts to fill in some of the data gaps of the HadCrut4 dataset.  The abstract is below.

 

 

http://onlinelibrary.wiley.com/doi/10.1002/qj.2297/abstract

 

"Incomplete global coverage is a potential source of bias in global temperature reconstructions if the unsampled regions are not uniformly distributed over the planet's surface. The widely used HadCRUT4 dataset covers on average about 84% of the globe over recent decades, with the unsampled regions being concentrated at the poles and over Africa. Three existing reconstructions with near-global coverage are examined, each suggesting that HadCRUT4 is subject to bias due to its treatment of unobserved regions.

Two alternative approaches for reconstructing global temperatures are explored, one based on an optimal interpolation algorithm and the other a hybrid method incorporating additional information from the satellite temperature record. The methods are validated on the basis of their skill at reconstructing omitted sets of observations. Both methods provide superior results than excluding the unsampled regions, with the hybrid method showing particular skill around the regions where no observations are available.

Temperature trends are compared for the hybrid global temperature reconstruction and the raw HadCRUT4 data. The widely quoted trend since 1997 in the hybrid global reconstruction is two and a half times greater than the corresponding trend in the coverage-biased HadCRUT4 data. Coverage bias causes a cool bias in recent temperatures relative to the late 1990s which increases from around 1998 to the present. Trends starting in 1997 or 1998 are particularly biased with respect to the global trend. The issue is exacerbated by the strong El Niño event of 1997-1998, which also tends to suppress trends starting during those years."

 

 

Edit: I'm surprised this has not been done before- I would imagine a direct measurement from satellite would be a better infill method than what GISS does in just extrapolation. 

 

#thepauseisanillusion

 

 

I performed a very similar method (infilling of the arctic instead of extrapolation) several years ago to prove to ORH and tacoman that the results are the same whether you use extrapolation (GISS) or if you infill the missing areas with satellite data. I even developed a name for the method but I forget what it was. It's still on my computer I think but my computer is dead for the moment. I guess I should have published.

 

Use of satellite data instead of extrapolation reduced the discrepancy between HadCRUT3 and GISS by maybe 5 or 10%, but the primary difference between HadCRUT3 and GISS was the source of SST data. The second largest source of difference was the fact that HadCRUT3 didn't include the arctic by any method. The third, and smallest source of difference (by far) was the use of extrapolation by GISS as opposed to infilling with satellite data, and it remains arguable whether extrapolation or use of satellite data is a better method long-term (due to potential biases in satellite data). 

 

 

If I understand correctly, the new HadCRUT4 is more similar to GISS than HadCRUT3 because it includes more of the arctic but still has blank areas due to the shorter extrapolations. 

[tacoman25]

For what its worth the AMO was 2nd warmest September on record behind 1998.

 

http://www.esrl.noaa.gov/psd/data/correlation/amon.us.long.data

 

 

I want to be perfectly clear I believe there is a climate shift happening now. 

 

Like I think 2014 will set the NCDC and GISS records.  UAH.  not sure yet.  It will depend what ENSO does. 

 

 

Due to what?

[tacoman25]

Its risen enough for the global temp record to be set.

 

This year has had every single month with a negative ONI.

 

Going back to December:  So that is negative the entire year.  And we are still sitting at .59C on GISS and .24C on UAH. 

 

Let's say we get a .60 or .61C on GISS for 2013.  November on CFS is already at .11C.  So far a .66C monthly equivalent.

 

.61C would be .05 below the record.  I think a 2010 like NINO would be .75 to .80C.  A weaker one in the .68 to .72C range.

 

I can't see a weak nino not causing the global temps to be less than .05C more than this year.

 

-0.3

2013

-0.6

-0.6

-0.4

-0.2

-0.2

-0.3

-0.3

-0.3

-0.3

 

 

 

 

Keep in mind, ONI is only one measure of ENSO. MEI was actually positive 3 bi-monthlies so far this year: http://www.esrl.noaa.gov/psd//people/klaus.wolter/MEI/table.html

 

Not even remotely close to the -ENSO MEI numbers seen in 2008 or 2011, for example. And 2012 had some big +MEI numbers and was in fact positive the entire second half of 2012.

[tacoman25]

I think so too, which is why earlier I said that unless we had some bizarre late developing El Nino this winter that maintained itself through summer (very rare for this to happen), 2014 wouldn't break any records.

 

2005 set a record despite being a weak El Nino, though it had the benefit of working off the tail end of the 2002 solar max (using the typical 2-3 year lag) and a general prolonged +PDO regime that extended back to 2002. I would guess that 2015 would need at least a weak El Nino in winter 2014-2015 to set a new record.

 

For GISS. Not for CRU, UAH, or RSS. In fact, none of those had 2005 all that close to 1998. That was a year where GISS was a pretty significant outlier, along with 2007.

[ORH_wxman]

For GISS. Not for CRU, UAH, or RSS. In fact, none of those had 2005 all that close to 1998. That was a year where GISS was a pretty significant outlier, along with 2007.

 

 

Well we were referring to GISS initially...since Friv was the one who brought up 2014 setting a new record and cited GISS.

[tacoman25]

Well we were referring to GISS initially...since Friv was the one who brought up 2014 setting a new record and cited GISS.

 

Understood. I just think it's important to remember GISS is just one of several sources, and it just happens to be the one that sets new temp records easier than the others.

[bluewave]

I think so too, which is why earlier I said that unless we had some bizarre late developing El Nino this winter that maintained itself through summer (very rare for this to happen), 2014 wouldn't break any records.

 

2005 set a record despite being a weak El Nino, though it had the benefit of working off the tail end of the 2002 solar max (using the typical 2-3 year lag) and a general prolonged +PDO regime that extended back to 2002. I would guess that 2015 would need at least a weak El Nino in winter 2014-2015 to set a new record.

 

Yeah, 2005 was able to do it wit the El Nino conditions that developed during the summer of 2004 that lasted into winter 2005.

[nflwxman]

Yeah, 2005 was able to do it wit the El Nino conditions that developed during the summer of 2004 that lasted into winter 2005.

 

To be clear- I agree the chances of breaking the record next year are slim without a bonified El nino.  But I was using the literal definition of El Nino- 3 trimonthly values above 0.5.  If we have 2 trimonthly values above 0.5 and the rest of the year ENSO positive- I think the chances venture in the arena of 15-20%, IMO.  It all depends on magnitude because obviously any scenario is on the table with ENSO at this point. 

[bluewave]

To be clear- I agree the chances of breaking the record next year are slim without a bonified El nino.  But I was using the literal definition of El Nino- 3 trimonthly values above 0.5.  If we have 2 trimonthly values above 0.5 and the rest of the year ENSO positive- I think the chances venture in the arena of 15-20%, IMO.  It all depends on magnitude because obviously any scenario is on the table with ENSO at this point. 

 

Yeah, 2014 could come very close to 2010 If an El Nino develops from say Jul-Dec. But the lag may result in a 2015 record

should an actual El Nino come to pass.

 

 

An interesting result is the time lags found. For volcanic eruptions the resulting cooling lags by about half a year, whereas the warming associated with El Nin ̃o events lags the multivariate ENSO index by 2–5 months. For ENSO the largest lag is found in the lower troposphere, whereas for solar forcing the lag in the surface data is larger. This is consistent with ENSO forcing the climate system from below (via ocean heat release) while solar irradiance forces the system from the top. The lags found here are consistent with those from Lean and Rind (2008) for the longer period 1889–2006, namely 6 months for volcanoes, 4 months for ENSO and 1 month for solar variations.

[tacoman25]

Yeah, 2014 could come very close to 2010 If an El Nino develops from say Jul-Dec. But the lag may result in a 2015 record

should an actual El Nino come to pass.

 

 

An interesting result is the time lags found. For volcanic eruptions the resulting cooling lags by about half a year, whereas the warming associated with El Nin ̃o events lags the multivariate ENSO index by 2–5 months. For ENSO the largest lag is found in the lower troposphere, whereas for solar forcing the lag in the surface data is larger. This is consistent with ENSO forcing the climate system from below (via ocean heat release) while solar irradiance forces the system from the top. The lags found here are consistent with those from Lean and Rind (2008) for the longer period 1889–2006, namely 6 months for volcanoes, 4 months for ENSO and 1 month for solar variations.

 

Right, and that's citing MEI (Multi-variate ENSO Index), which has actually been positive three bi-monthlies this year and was quite positive the second half of 2012. So it isn't so surprising that 2013 has been as warm as it has when you look at MEI, instead of just ONI.

[The_Global_Warmer]

CFS still hasn't dropped under the .20C benchmark on weatherbell.  I believe it's been about 72 hours.  It's up to .113C on the month.

 

AMSU Channel 6 temps are still running very warm. 

 

 

Global ssta have gone up three weeks in a row.  now at .25C+ again.  They will hover between .25 and .30C for a while.  The Southern Pacific and Indian Oceans have seen warmth explode. 

 

 

the cool is being overwhelmed everywhere.  It's only a matter of time now.  I am not trying to push an agenda.  Most of the cool is in the Eastern Pacific.  There is some along the Southern Ocean.   But further South heat is building.. 

 

Those pockets of warm ssta are getting so large and warm. 

 

I just don't see the kind of cool months we need going forward to not set a record. 

 

 

This is the basics of AGW.  We expected the heat content to rise faster.  So it shouldn't be surprising to see it evolving like this.

 

 

[skierinvermont]

For GISS. Not for CRU, UAH, or RSS. In fact, none of those had 2005 all that close to 1998. That was a year where GISS was a pretty significant outlier, along with 2007.

 

This is because of the inclusion in the arctic and the fact that 2005 was a blowtorch in the arctic (which can be verified independently of GISS). 

[chubbs]

New study  improves HadCRUT4 series by using satellite data to fill gaps

Coverage bias in the HadCRUT4 temperature series and its impact on recent temperature trends

Incomplete global coverage is a potential source of bias in global temperature reconstructions if the unsampled regions are not uniformly distributed over the planet's surface. The widely used HadCRUT4 dataset covers on average about 84% of the globe over recent decades, with the unsampled regions being concentrated at the poles and over Africa. Three existing reconstructions with near-global coverage are examined, each suggesting that HadCRUT4 is subject to bias due to its treatment of unobserved regions.

Two alternative approaches for reconstructing global temperatures are explored, one based on an optimal interpolation algorithm and the other a hybrid method incorporating additional information from the satellite temperature record. The methods are validated on the basis of their skill at reconstructing omitted sets of observations. Both methods provide superior results than excluding the unsampled regions, with the hybrid method showing particular skill around the regions where no observations are available.

Temperature trends are compared for the hybrid global temperature reconstruction and the raw HadCRUT4 data. The widely quoted trend since 1997 in the hybrid global reconstruction is two and a half times greater than the corresponding trend in the coverage-biased HadCRUT4 data. Coverage bias causes a cool bias in recent temperatures relative to the late 1990s which increases from around 1998 to the present. Trends starting in 1997 or 1998 are particularly biased with respect to the global trend. The issue is exacerbated by the strong El Niño event of 1997-1998, which also tends to suppress trends starting during those years.

http://onlinelibrary.wiley.com/doi/10.1002/qj.2297/abstract

[ORH_wxman]

 

New study  improves HadCRUT4 series by using satellite data to fill gaps

Coverage bias in the HadCRUT4 temperature series and its impact on recent temperature trends

Incomplete global coverage is a potential source of bias in global temperature reconstructions if the unsampled regions are not uniformly distributed over the planet's surface. The widely used HadCRUT4 dataset covers on average about 84% of the globe over recent decades, with the unsampled regions being concentrated at the poles and over Africa. Three existing reconstructions with near-global coverage are examined, each suggesting that HadCRUT4 is subject to bias due to its treatment of unobserved regions.

Two alternative approaches for reconstructing global temperatures are explored, one based on an optimal interpolation algorithm and the other a hybrid method incorporating additional information from the satellite temperature record. The methods are validated on the basis of their skill at reconstructing omitted sets of observations. Both methods provide superior results than excluding the unsampled regions, with the hybrid method showing particular skill around the regions where no observations are available.

Temperature trends are compared for the hybrid global temperature reconstruction and the raw HadCRUT4 data. The widely quoted trend since 1997 in the hybrid global reconstruction is two and a half times greater than the corresponding trend in the coverage-biased HadCRUT4 data. Coverage bias causes a cool bias in recent temperatures relative to the late 1990s which increases from around 1998 to the present. Trends starting in 1997 or 1998 are particularly biased with respect to the global trend. The issue is exacerbated by the strong El Niño event of 1997-1998, which also tends to suppress trends starting during those years.

http://onlinelibrary.wiley.com/doi/10.1002/qj.2297/abstract

 

Posted twice ysterday in this thread

 

There is a new paper that attempts to fill in some of the data gaps of the HadCrut4 dataset. The abstract is below.

http://onlinelibrary.wiley.com/doi/10.1002/qj.2297/abstract

"Incomplete global coverage is a potential source of bias in global temperature reconstructions if the unsampled regions are not uniformly distributed over the planet's surface. The widely used HadCRUT4 dataset covers on average about 84% of the globe over recent decades, with the unsampled regions being concentrated at the poles and over Africa. Three existing reconstructions with near-global coverage are examined, each suggesting that HadCRUT4 is subject to bias due to its treatment of unobserved regions.

Two alternative approaches for reconstructing global temperatures are explored, one based on an optimal interpolation algorithm and the other a hybrid method incorporating additional information from the satellite temperature record. The methods are validated on the basis of their skill at reconstructing omitted sets of observations. Both methods provide superior results than excluding the unsampled regions, with the hybrid method showing particular skill around the regions where no observations are available.

Temperature trends are compared for the hybrid global temperature reconstruction and the raw HadCRUT4 data. The widely quoted trend since 1997 in the hybrid global reconstruction is two and a half times greater than the corresponding trend in the coverage-biased HadCRUT4 data. Coverage bias causes a cool bias in recent temperatures relative to the late 1990s which increases from around 1998 to the present. Trends starting in 1997 or 1998 are particularly biased with respect to the global trend. The issue is exacerbated by the strong El Niño event of 1997-1998, which also tends to suppress trends starting during those years."

Edit: I'm surprised this has not been done before- I would imagine a direct measurement from satellite would be a better infill method than what GISS does in just extrapolation.

#thepauseisanillusion

New paper in the Quarterly Journal of the Royal Meteorological Society:

Coverage bias in the HadCRUT4 temperature series and its impact on recent temperature trends

http://onlinelibrary.wiley.com/doi/10.1002/qj.2297/abstract

Abstract:

Short explanatory video by authors:

http://www.youtube.com/watch?v=GhJR3ywIijo

Edit: Sorry, didn't see nflwxman had already posted.

[nflwxman]

The new adjusted dataset is pretty big news in climatology IMO.  It was always strange how 1998 was such a warm year compared to 2005 and 2010 on the HadCrut4 data set.  I believe this is because much of the arctic was not accounted for, which is less impacted by ENSO swings.  The new trend since 1997 is 0.11-0.12 C/decade.  Skier, I wonder if you recreated your analysis of filtering out natural variability in the climate record with this new data how the results would change.

[ORH_wxman]

 

The new adjusted dataset is pretty big news in climatology IMO.  It was always strange how 1998 was such a warm year compared to 2005 and 2010 on the HadCrut4 data set.  I believe this is because much of the arctic was not accounted for, which is less impacted by ENSO swings.  The new trend since 1997 is 0.11-0.12 C/decade.  Skier, I wonder if you recreated your analysis of filtering out natural variability in the climate record with this new data how the results would change.

The GISS trend (which covers the poles) from 1997 is 0.07C per decade...so now Hadcrut4 is 0.05C more than that? Even the recently warm UAH doesn't have anything close to that high at 0.085C per decade.

This study essentially turns Hadcrut4 into a warm outlier when compared to other datasets with full coverage...assuming your 0.11-0.12C per decade trend is correct. I have not read the paper since it is paywalled, so I am not sure if they explain the difference in full.

[Bannor]

 

The GISS trend (which covers the poles) from 1997 is 0.07C per decade...so now Hadcrut4 is 0.05C more than that? Even the recently warm UAH doesn't have anything close to that high at 0.085C per decade.

This study essentially turns Hadcrut4 into a warm outlier when compared to other datasets with full coverage...assuming your 0.11-0.12C per decade trend is correct. I have not read the paper since it is paywalled, so I am not sure if they explain the difference in full.

 

 

This is from the authors' background material:

 

How do the results compare to other measures of global temperature?

 

The other widely quoted measures of global mean surface temperature are the GISTEMP record from the National Aeronautics and Space Administration (NASA) and the NCDC record from the National Oceanic and Atmospheric Administration (NOAA). Our results show slightly faster warming over the past 16 years than the NASA data, and significantly faster warming that NOAA. What is the reason for this discrepancy?

 

There are two known observational biases which impact recent temperature trends. Coverage bias, addressed in this paper, impacts the Met Office and NOAA data. A bias in sea surface temperature observations (arising from a recent transition from ships to buoys) is present in the NASA and NOAA data. We anticipate that when both of these biases are corrected, the resulting records will show even better agreement.

 

If the Met Office sea surface temperature corrections are applied to the NASA data, the resulting 16 year trend (i.e. 1997-2012) is 0.103°C/decade. Using the Met Office data and a similar reconstruction method we obtain a similar trend of 0.108°C/decade. Our best reconstruction including the satellite data shows a trend of 0.119°C/decade.

 

 

http://www-users.york.ac.uk/~kdc3/papers/coverage2013/background.html#compare