...

[Jonger]

I've been wondering about the PDO and it's impact on land only temperatures, so I completed an analysis comparing global tropospheric temps versus land only.  Based on the fact the land can't absorb or release energy with significant inertia (La Nina/El Nino) as the oceans can, one would expect the global warming signal to be more stable.  This is not to say the land temperature trend is not impacted by ocean oscillations and other natural factors (as hobbyists, we all know that). However, the lower atmospheric temperature over land is clearly less impacted by changes in natural ocean oscillations versus the lower atmosphere temperatures over the ocean, as shown in the data below.  If you look at the UAH land only temperature record, you will see there is truly not much of a "pause" in the warming trend that you see globally the last decade. This supports that the energy imbalance remains generally the same/higher than what we have seen in the past 2 decades.  Please note, the period between 1992-1994 seems to be dramatically impacted by the Pinatubo explosion, thus I would not start or finish any trends there. Also, UHI is not feasible here as an explanation due to the fact we are measuring the lower troposphere.

 

http://woodfortrees.org/plot/uah-land/from:1979/to:2013/mean:12

 

Land Trends:

 

1979-2005: 0.1519 C/decade

 

1979-2013: 0.181 C/decade

 

1998-2013 ("Pause one"): 0.1901 C/decade

 

2001-2013 ("Pause two"):  0.1926 C/decade

 

Ocean+Land Trends:

 

1979-2005: 0.1336 C/decade

 

1979-2013: 0.1338 C/decade

 

1998-2013 ("Pause one"): 0.0966 C/decade

 

2001-2013 ("Pause two"):  0.002 C/decade 

 

So the question to me is:

 

If more than 40% of the warming in the later half of the 20th century was caused by natural factors, wouldn't you see the land only trend significantly slow down with the global trend (since oceans are now absorbing more heat)?  It appears as if the opposite has happened.  To me, this seems like the ocean right now is the only major driver in masking the upward global trend shown in the land only dataset.

 

Disclaimer: Using trends under 30 years is always a dangerous prospect, but given that the satellite data set is so short, I had no choice.  Perhaps a similar analysis could be completed with the GISS.

 

Its a real shame we don't have a longer UAH temp record.

[ORH_wxman]

Land temps lag ocean a bit...CRUTem4 (land only component of Hadcrut4) has a negative trend from mid 2001. RSS land only is negative from the same time period. UAH is positive, and significantly so, but its an outlier. So the analysis using only one dataset (UAH in this case) should probably be taken with some caution.

 

You can see the same phenomenon from the 1940s-1970s on CRUTem4 where the negative trend on them starts a bit later and ends a bit later than the ocean component.

 

But given that the ocean is 70% of the surface, they are going to be a primary driver in sfc temps.

[nflwxman]

Land temps lag ocean a bit...CRUTem4 (land only component of Hadcrut4) has a negative trend from mid 2001. RSS land only is negative from the same time period. UAH is positive, and significantly so, but its an outlier. So the analysis using only one dataset (UAH in this case) should probably be taken with some caution.

 

You can see the same phenomenon from the 1940s-1970s on CRUTem4 where the negative trend on them starts a bit later and ends a bit later than the ocean component.

 

But given that the ocean is 70% of the surface, they are going to be a primary driver in sfc temps.

 

 

It appears CRUTem4 does not have a negative trend, it's just nearly as positive UAH since 2001 (around 0.04 C/decade for land versus -0.02 C/decade land/ocean ).  But regardless, there is a very large gap between RSS and UAH, possibly related to activity at the poles?  I would image UAH is probably a more accurate representation of the overall trend given the insane warming trend in and around northern Greenland.  Both Best and GISS also show about 0.08 C/decade since 2001 for land warming.

 

Secondly, there is a bit of a lag, but it's a few months. Not several years.  The GISS temperature data set tracks very well ocean versus land (within 4 months or so).  

 

Edit:  I realized just now you said mid 2001.  You are correct on that.

[nflwxman]

Another way to look at this:

 

Look at the GISS dataset and the land versus land/ocean anomaly for the past 50 years.  The difference between land and global temperatures becomes very obvious throughout time and is growing fastest since the PDO switch in 1999.  If the AGW signal was muted, one would see the land temperatures eventually track closer to ocean/global temps due to balancing of radiative forcing across the globe (if no significant positive forcing was present). In my mind, this the growing disparity of the land only temperatures versus the global temperatures since 1999 in fact shows that the ocean with high variability and inertia is muting the global signal (acting as a pseudo negative forcing) to global temps, while the forcing still exists as strong as ever. 

 

This is how i see it at least.  Also, I can't post excel graphs here. Any reason why?  

[ORH_wxman]

Here are the two components of Hadcrut4 since 2001:

 

 

 

The other global datasets on woodfortrees do not allow us to seperate land and ocean...just land vs overall global temps which is kind of annoying.

GISS land doesn't give us a negative trend until we start in late 2004...so that is a solid 3 year difference versus Hadcrut4. However, its overall global trend is negative starting at a similar time to Hadcrut4. (December 2000 vs February 2001) This would imply that the GISS ocean trend is more robustly negative than the Hadcrut trend.

[tacoman25]

Another way to look at this:

 

Look at the GISS dataset and the land versus land/ocean anomaly for the past 50 years.  The difference between land and global temperatures becomes very obvious throughout time and is growing fastest since the PDO switch in 1999.  If the AGW signal was muted, one would see the land temperatures eventually track closer to ocean/global temps due to balancing of radiative forcing across the globe (if no significant positive forcing was present). In my mind, this the growing disparity of the land only temperatures versus the global temperatures since 1999 in fact shows that the ocean with high variability and inertia is muting the global signal (acting as a pseudo negative forcing) to global temps, while the forcing still exists as strong as ever. 

 

This is how i see it at least.  Also, I can't post excel graphs here. Any reason why?  

 

This is the old-school idea. Most experts now acknowledge the true flip to the -PDO phase occurred around 2007-08. Even NASA put out a statement in April 2008 indicating this.

 

I can give you plenty of evidence for this if you'd like.

[nflwxman]

This is the old-school idea. Most experts now acknowledge the true flip to the -PDO phase occurred around 2007-08. Even NASA put out a statement in April 2008 indicating this.

I can give you plenty of evidence for this if you'd like.

That may be correct, but it is tangential to the argument I was making. The PDO was certainly overall much lower after the 1998

Super nino, leading to shorter and less intense El ninos after. Why does the discrepancy between land and ocean anomalies continue to grow the fastest between in the 21st century when they were nearly identical in the 50s-80s? Theoretically if there were no significant positive forcing (anthropogenic) we should have anomalies between match up fairly well between land and ocean due to radiative balancing across the planet. My point is that I believe the global warming signal may be able to be seen on land and not the ocean simply because the ocean is absorbing heat to lower depths, while the land surface is less affected and thus retains a bit more of the additional forcing. If AGW were to stop right now, it's my belief the the land and ocean anomalies should ultimately come into equilibrium. At this point, that can't happen over land since the forcing is growing. Just a thought. Would like to hear any feedback

[tacoman25]

That may be correct, but it is tangential to the argument I was making. The PDO was certainly overall much lower after the 1998

Super nino, leading to shorter and less intense El ninos after. Why does the discrepancy between land and ocean anomalies continue to grow the fastest between in the 21st century when they were nearly identical in the 50s-80s? Theoretically if there were no significant positive forcing (anthropogenic) we should have anomalies between match up fairly well between land and ocean due to radiative balancing across the planet. My point is that I believe the global warming signal may be able to be seen on land and not the ocean simply because the ocean is absorbing heat to lower depths, while the land surface is less affected and thus retains a bit more of the additional forcing. If AGW were to stop right now, it's my belief the the land and ocean anomalies should ultimately come into equilibrium. At this point, that can't happen over land since the forcing is growing. Just a thought. Would like to hear any feedback

 

Actually, winter 2002-03 had one of the strongest +PDOS on record. Every winter from 2002-2007 had +PDO. For the sake of accuracy.

 

I'm not sure what you're trying to prove? That oceanic phases have a significant effect on global temp trends? I'm not sure there is an increasing divergence between land and global temp trends, if that is what you're trying to say. It seems to depend on what dataset you prefer.

[ORH_wxman]

There is no divergence between the CRUTem4 dataset and the HadSST3 dataset (the SST source of Hadcrut4)....GISS and UAH have divergence. RSS does not have divergence once again. So two datasets have divergence and 2 do not.

The difference isn't really explained by the arctic either since Hadcrut4 covers most arctic land...the areas it doesn't cover are chunks of the arctic ocean, which should not affect land temperature datasets. I'm not sure there is enough data to come to any real conclusion.

[nflwxman]

Comparing the Hadcrut4 global mean versus the hadcrut4 land only, shows a strong divergence between anomalies starting in 1999.  RSS shows exactly the same thing.  It appears to be most pronounced in the non sat data sets.   Perhaps we are talking about two different variables here?  Remember, I'm not looking at sea surface temperature.  I'm looking at surface temperatures.

 

 

 

http://woodfortrees.org/plot/crutem4vgl/from:1979/to:2014/mean:12/plot/hadcrut4gl/from:1979/to:2014/mean:12

 

 

http://woodfortrees.org/plot/rss-land/from:1979/to:2014/mean:12/plot/rss/from:1979/to:2014/mean:12

 

 

 

 

UAH shows the divergence, but it occurs post 2005 (since there has been some overall surface temperature cooling.)

[ORH_wxman]

Comparing the Hadcrut4 global mean versus the hadcrut4 land only, shows a strong divergence between anomalies starting in 1999.  RSS shows exactly the same thing.  It appears to be most pronounced in the non sat data sets.   Perhaps we are talking about two different variables here?  Remember, I'm not looking at sea surface temperature.  I'm looking at surface temperatures.

 

 

 

http://woodfortrees.org/plot/crutem4vgl/from:1979/to:2014/mean:12/plot/hadcrut4gl/from:1979/to:2014/mean:12

 

 

http://woodfortrees.org/plot/rss-land/from:1979/to:2014/mean:12/plot/rss/from:1979/to:2014/mean:12

 

 

 

 

UAH shows the divergence, but it occurs post 2005 (since there has been some overall surface temperature cooling.)

It looks like almost all the divergence occurred in the wake of the 1998 El Nino. I was comparing trends since 2001 and they are similar on land vs ocean which indicates that the divergence was sudden and not a gradual process. The RSS divergence is far less pronounced but still looks to occur at the same time.

It appears GISS has big divergence too in the 1917-1930 timeframe before it caught back up. The GISS divergence also seems to be more gradual in the past 30 years versus some of the other datasets.

[nflwxman]

It looks like almost all the divergence occurred in the wake of the 1998 El Nino. I was comparing trends since 2001 and they are similar on land vs ocean which indicates that the divergence was sudden and not a gradual process. The RSS divergence is far less pronounced but still looks to occur at the same time.

It appears GISS has big divergence too in the 1917-1930 timeframe before it caught back up. The GISS divergence also seems to be more gradual in the past 30 years versus some of the other datasets.

Looks more sudden on the sat datasets and but continuously increasing on GISS/Hadcrut.  Perhaps that is due to the fact we are measuring at a much higher level where ocean/land temps are more well blended?  I'm surprised there is not much divergence in the 1940's when the great climate shift occured.  But I a guess anthropogenic forcing was relatively weak at that point.  Anyways, it's just an interesting tidbit.  I believe it shows a signal in the land data, but it's hard to draw any quantative conclusions from it without a much much more detailed analysis.

[Snow_Miser]

Roy Spencer and Judith Curry both have papers that have gotten accepted. Both of which concern internal climate variability. Should be interesting to see what they are about when they get published.

 

http://www.drroyspencer.com/2013/09/a-turning-point-for-the-ipcc-and-humanity/

 

"We also have our own paper, slated to be published on October 31, which will present new results on climate sensitivity and the role of natural climate variations in recent warming."

 

http://judithcurry.com/2013/09/17/consensus-denialism/#comment-381667

 

"My understanding of climate is not helped much by climate models. Stay tuned, our big paper on natural internal climate variability just got accepted by Climate Dynamics

Ask yourself why the common sense stuff that I say is regarded as news."

 

[A-L-E-K]

thanks for posting

[skierinvermont]

They cite the TOA energy imbalance as .5-1W/m2. The estimates I have seen are on the lower end of this range. A higher estimate would be more consistent with heat uptake by the oceans and delayed surface warming.

 

This has been my primary objection to the idea the PDO is responsible for the slow surface warming. If the PDO (or any other form of internal variability) and not radiative forcing is responsible for the slow rate of surface warming, then ocean heat uptake should be accelerating and probably be around 1W/m2 now. 

 

Most estimates I have seen have placed it closer to .5W/m2 without any acceleration from pre-2000 rates. This is inconsistent with increased ocean storage due to the PDO. 

 

I guess I should check the source for the higher 1W/m2 estimate. If the earth's energy imbalance has indeed increased to 1W/m2, that could explain the slower rate of surface warming.

[AvantHiatus]

They cite the TOA energy imbalance as .5-1W/m2. The estimates I have seen are on the lower end of this range. A higher estimate would be more consistent with heat uptake by the oceans and delayed surface warming.

 

This has been my primary objection to the idea the PDO is responsible for the slow surface warming. If the PDO (or any other form of internal variability) and not radiative forcing is responsible for the slow rate of surface warming, then ocean heat uptake should be accelerating and probably be around 1W/m2 now. 

 

Most estimates I have seen have placed it closer to .5W/m2 without any acceleration from pre-2000 rates. This is inconsistent with increased ocean storage due to the PDO. 

 

I guess I should check the source for the higher 1W/m2 estimate. If the earth's energy imbalance has indeed increased to 1W/m2, that could explain the slower rate of surface warming.

Good call, how would you explain the energy imbalance without citing the -PDO sequestration of heat? Seems like the best candidate to explain the deep ocean warming.

[skierinvermont]

Good call, how would you explain the energy imbalance without citing the -PDO sequestration of heat? Seems like the best candidate to explain the deep ocean warming.

 

Except most estimates I have seen show no acceleration in OHC increase. The obvious conclusion is that the PDO is not the primary driver of slower surface warming. 

[The_Global_Warmer]

2013 is still the highest OHC year adn it won't be that close unless OND comes in much cooler which is not likely.

 

 

 

 

[skierinvermont]

The charts show it clearly: no acceleration.

 

Obvious conclusion: it's not the PDO. 

[AvantHiatus]

The charts show it clearly: no acceleration.

 

Obvious conclusion: it's not the PDO. 

I understand your point and agree to some extent, for whatever its worth heat could be stored below 700m and would not be depicted on that chart (the first one). Additionally, we still need to find out where the "missing heat" is or if it's being diminished by some negative feedback such as atmospheric sulfates.

 

I would argue that 700m to 200om shows an accelerated warming trend. Too bad the red line does not go back further. I have a hard time using it to conclude anything.

[Jonger]

2013 is still the highest OHC year adn it won't be that close unless OND comes in much cooler which is not likely.

 

 

 

 

 

Its a bummer we only have that "data" since the mid 1950's... Since its highly unlikely any pre-1960's OHC had anything to do with GHGs, I would love to see that chart... I bet its been rising at that same rate for 200 years. Heat is probably fed into the ocean constantly until a volcano or another forcing causes it to lose heat. 

 

Data shows a warming globe since the LIA, there is no reason to believe this hasn't been a constant for a few hundred years.

[StudentOfClimatology]

Its a bummer we only have that "data" since the mid 1950's... Since its highly unlikely any pre-1960's OHC had anything to do with GHGs, I would love to see that chart... I bet its been rising at that same rate for 200 years. Heat is probably fed into the ocean constantly until a volcano or another forcing causes it to lose heat.

Data shows a warming globe since the LIA, there is no reason to believe this hasn't been a constant for a few hundred years.

You might be correct. A vast quantity of peer-reviewed of research was recently put into 20th century sea level rise, by J. M. Gregory, N. J. White, J. A. Church, M. F. P. Bierkens, J. E. Box, M. R. van den Broeke, J. G. Cogley, X. Fettweis, E. Hanna, P. Huybrechts, L. F. Konikow, P. W. Leclercq, B. Marzeion, J. Oerlemans, M. E. Tamisiea, Y. Wada, L. M. Wake, and R. S.W. van de Wal.

Paper here: http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00319.1

The findings suggest that sea levels have been rising at a fairly constant rate since 1900, despite the suspected increase in anthropogenic forcing. This suggest the contributive factors were perturbed to a similar extent, pre 1950:

Abstract below:

Confidence in projections of global-mean sea-level rise (GMSLR) depends on an ability to account for GMSLR during the 20th century. There are contributions from ocean thermal expansion, mass loss from glaciers and ice sheets, groundwater extraction and reservoir impoundment. We have made progress towards solving the “enigma” of 20th-century GMSLR—that is, the observed GMSLR has been found to exceed the sum of estimated contributions, especially for the earlier decades. We propose that: thermal expansion simulated by climate models may previously have been underestimated owing to their not including volcanic forcing in their control state; the rate of glacier mass loss was larger than previously estimated, and was not smaller in the first than in the second half of the century; the Greenland ice-sheet could have made a positive contribution throughout the century; groundwater depletion and reservoir impoundment, which are of opposite sign, may have been approximately equal in magnitude. We show that it is possible to reconstruct the timeseries of GMSLR from the quantified contributions, apart from a constant residual term which is small enough to be explained as a long-term contribution from the Antarctic ice-sheet. The reconstructions account for the approximate constancy of the rate of GMSLR during the 20th century, which shows small or no acceleration, despite the increasing anthropogenic forcing. Semi-empirical methods for projecting GMSLR depend on the existence of a relationship between global climate change and the rate of GMSLR, but the implication of our closure of the budget is that such a relationship is weak or absent during the 20th century.

Contributions:

1 NCAS-Climate, University of Reading, Reading, UK.

2 Met Office Hadley Centre, Exeter, UK.

3 CAWCR, CSIRO Marine and Atmospheric Research, Hobart, Australia.

4 Department of Physical Geography, Utrecht University, Utrecht, The Netherlands.

5 Deltares, Delft, The Netherlands.

6 Byrd Polar Research Center, and Department of Geography, Atmospheric Sciences Program, The Ohio State University, Columbus, Ohio, USA.

7 Institute for Marine and Atmospheric research Utrecht, Utrecht University, Utrecht, The Netherlands.

8 Department of Geography, Trent University, Peterborough, Ontario, Canada.

9 Département de Géographie, Université de Liège, Liège, Belgium.

10 Department of Geography, University of Sheffield, Sheffield, UK.

11 Earth System Sciences and Departement Geografie, Vrije Universiteit Brussel, Brussels, Belgium.

12 U. S. Geological Survey, Reston, Virginia, USA.

13 Centre of Climate and Cryosphere, Institute of Meteorology and Geophysics, University of Innsbruck, Innsbruck, Austria.

14 National Oceanography Centre, Liverpool, UK.

15 Department of Geography, University of Calgary, Calgary, Canada.

[skierinvermont]

Its a bummer we only have that "data" since the mid 1950's... Since its highly unlikely any pre-1960's OHC had anything to do with GHGs, I would love to see that chart... I bet its been rising at that same rate for 200 years. Heat is probably fed into the ocean constantly until a volcano or another forcing causes it to lose heat. 

 

Data shows a warming globe since the LIA, there is no reason to believe this hasn't been a constant for a few hundred years.

 

OHC probably has been rising fairly steadily for the last 100 years in approximate step with surface temperature. Both of them are response to the same phenomenon: positive radiative forcing. However, OHC probably decreased from 1850 to 1900 as surface temperatures cooled. 

 

Ever increasing OHC and surface temperatures require ever increasing radiative forcing. Your proposed 'the oceans just warm until a volcano or something else cause it to lose all that heat' doesn't fit the observation of ever increasing OHC and surface temperature. Such an observation requires an ever growing/strengthening cause of that warming. Otherwise the system would simply warm up quickly at first and then the warming would decelerate.

 

In addition, negative forcing from even the largest volcanoes is strong only for 2-3 years and is spent after 5-10 years. 

 

The observation of rising surface temperature and OHC is only consistent with ever increasing radiative forcing. This means constantly growing and new causes of the imbalance. Hypothetical possibilities include increasing GHG concentrations, ever increasing solar forcing, or decreasing albedo. Since solar forcing had peaked by mid-century (and the observed changes were small), and we have an observed strengthening of the GHG effect, and radiative transfer code tells us that doubling CO2 provides 1.2W/m2 of radiative forcing, the answer is clearly primarily CO2 strengthening the greenhouse effect+positive feedbacks. 

 

You still seem to struggle with the concept of radiative forcing. Temperature change is a response to historical changes in radiative forcing. OHC change is an expression of the imbalance that remains. 

 

In addition, a reminder as to just how large the current imbalance is seems appropriate. The earth is currently gaining heat at a rate of about .5W/m2 or perhaps a bit higher. That's equivalent to 4 hiroshima bombs every second. 

 

The surface warming of nearly 1C since 1900 also means that the earth, if it had the same atmosphere that it did in 1900, would be radiating energy at a rate of ~3W/m2 faster than it was before the surface warmed by 1C.

 

The earth should be losing heat at a rate of 20 hiroshima bombs every second.

 

Instead it is gaining heat at a rate of 4 hiroshima bombs every second. 

 

Why is it not losing heat so rapidly? Because the composition of the atmosphere now prevents surface radiation from escaping as easily as it once did.

[StudentOfClimatology]

The observation of rising surface temperature and OHC is only consistent with ever increasing radiative forcing.

Not necessarily. The thermal capacity of the ocean system requires that thermal equilibrium be achieved gradually. However, some peer-reviewed estimates only require a few decades for full equilibrium above 70m, such as Cress/Goldenburg et al.

These are fairly basic equations, so much of the work here was completed in the 1980s/90s.

http://onlinelibrary.wiley.com/doi/10.1029/JC086iC01p00498/abstract;jsessionid=DC048DFAED6BF27B7B67B223681535F4.f01t03?deniedAccessCustomisedMessage=&userIsAuthenticated=false

Time-dependent global warming due to increasing levels of atmospheric carbon dioxide has been estimated by employing an ocean-land global climate model. Ocean heat capacity is incorporated by means of a global ocean model having a 70 m deep mixed layer, with heat being transported from the mixed layer to deeper waters by eddy diffusion. The time-dependent increase in atmospheric CO2, from 1860 to 2025, is taken from carbon-cycle models. The model results suggest that ocean heat capacity will produce a lag in CO2-induced global warming of about 2 decades. For example, without inclusion of ocean heat capacity the model predicts that an increase in global surface temperature of 1°C, relative to 1860, will occur by 1988. But when ocean heat capacity is included, the 1°C warming is delayed until 2006–2012, this range of times corresponding to no land-ocean advective coupling (2006) and complete land-ocean coupling (2012). By 2025, when the assumed atmospheric CO2 content is twice the 1860 value, the model predicts global warming of 1.5°–1.8°C, in contrast to 3.1°C when ocean heat capacity is neglected.

Obviously, the deeper you go, the longer it'll take to initially equilibrate. The upper ocean/surface will equilibriate well before the deep waters.

Radiative transfer code tells us that doubling CO2 provides 1.2W/m2 of radiative forcing, the answer is clearly primarily CO2 strengthening the greenhouse effect+positive feedbacks.

The current theory suggests a 3.7W/m^2 forcing would result, not 1.2W/m^2, viewed at the TOA, although it'd be less at the planetary surface. However, that figure is somewhat theoretical as the mathematics assume a state of full local-thermodynamic-equilibrium without interference, which is far from the case in an atmosphere with multiple IR-reactive gases. That's why millions of dollars have been spent on satellite systems like CERES and AIRS. We need to monitor the specific dynamics/saturations/regressions within our own atmospheric window to adequately gauge what the real value is.

However, we're currently working on a major solution to this problem. The RAVAN project is expected to launch in 2015. You might call it the satellite version of ARGO...we're going to have a ton of small satellites, or "cubesats" orbiting the earth, providing us with an unprecedented look into the inter workings of the planetary energy budget:

http://www.sciencedaily.com/releases/2013/12/131210113317.htm

Dec. 10, 2013 — A new, low-cost cubesat mission led by the Johns Hopkins Applied Physics Laboratory in Laurel, Md. will demonstrate technology needed to measure the absolute imbalance in Earth's radiation budget for the first time, giving scientists valuable information to study our climate.

RAVAN will use a small, accurate radiometer, developed at L-1 Standards and Technology and not much larger than a deck of cards, to measure the strength of Earth's outgoing radiation across the entire spectrum of energy -- from the ultraviolet to the far infrared. "ERI is too small to be measured by previous, current, or planned future space assets," says co-investigator Warren Wiscombe, a climate scientist at Goddard.

The secret to RAVAN's precise measurements is a "forest" of carbon nanotubes, grown at APL, that serve as the radiometer's light absorber. "The carbon nanotubes are a very deep black across the energy spectrum, which will let the radiometer gather virtually all the light reflected and emitted from the planet," says Swartz.

RAVAN represents the first step toward a constellation of cubesats, each no larger than a loaf of bread, that would provide global coverage of Earth's total outgoing radiation throughout the day and night, and data to answer long-standing questions about Earth's climate future.

[skierinvermont]

Not necessarily. The thermal capacity of the ocean system requires that thermal equilibrium be achieved gradually. However, some peer-reviewed estimates only require a few decades for full equilibrium above 70m, such as Cress/Goldenburg et al.

 

 

Yes necessarily. If both surface temperatures rise, and OHC continues to rise, there must necessarily have been increased radiative forcing. Otherwise the increased surface temperature would have reduced the energetic imbalance of the earth and slowed, eliminated or reversed the rise in OHC. I suggest you focus more energy on reading rather than being a contrarian. Obviously it takes time for the oceans (and surface temperature) to reach thermal equilibrium with a radiative forcing. But just because the earth is not yet in perfect equilibrium does not mean that surface temperature rise and OHC increase will increase linearly until equilibrium is reached. In fact, the process is not remotely linear. Without new positive radiative forcing the rate of surface temperature and OHC increase quickly slows to a snails pace after the initial rapid response. The majority of the surface temperature response to a sudden 1W/m2 forcing would probably take place within a few years, and the initial negative energy imbalance would be less than half of what it was immediately following the change in forcing. 

 

Surface temperatures cannot rise significantly without either a major decrease in the net energy balance of the earth, or an external radiative forcing. 

 

The 1.2W/m2 figure was a brain fart. I meant 3.7W/m2. 

 

My statement concerning 20th century observations was correct. 

 

 

The observation of rising surface temperature and OHC is only consistent with ever increasing radiative forcing. 

 

 

 

Please explain to us how OHC and temperatures can rise with constant forcing. The rise of either or both would quickly slow without a new increase in forcing to sustain the increase. 

[StudentOfClimatology]

Yes necessarily. If both surface temperatures rise, and OHC continues to rise, there must necessarily have been increased radiative forcing. Otherwise the increased surface temperature would have reduced the energetic imbalance of the earth and slowed, eliminated or reversed the rise in OHC. I suggest you focus more energy on reading rather than being a contrarian.

Did you read the Cress/Goldenburg paper? The oceans are the interface used to calculate the imbalance from planetary equilibrium. The oceans regulate lower tropospheric air temperature (SSTs lead air temps by a few months). The oceans as a whole hold 99% of the thermal energy budget, so thats not a surprise. So model projections of warming after doubling CO2 take this into account, which is why even if we were to stop emitting CO2 now, we wouldn't reach thermal equilibrium until 2075 or so.

Hansen/Russel et al: http://m.sciencemag.org/content/229/4716/857.short

The factors that determine climate response times were investigated with simple models and scaling statements. The response times are particularly sensitive to (i) the amount that the climate response is amplified by feedbacks and (ii) the representation of ocean mixing. If equilibrium climate sensitivity is 3°C or greater for a doubling of the carbon dioxide concentration, then most of the expected warming attributable to trace gases added to the atmosphere by man probably has not yet occurred. This yet to be realized warming calls into question a policy of "wait and see" regarding the issue of how to deal with increasing atmospheric carbon dioxide and other trace gases.

Obviously it takes time for the oceans (and surface temperature) to reach thermal equilibrium with a radiative forcing. But just because the earth is not yet in perfect equilibrium does not mean that surface temperature rise and OHC increase will increase linearly until equilibrium is reached. In fact, the process is not remotely linear. Without new positive radiative forcing the rate of surface temperature and OHC increase quickly slows to a snails pace after the initial rapid response.

It'll definitely slow at the surface and upper ocean once equilibrium is reached in the mixing layer...that has to be achieved first. How quickly that occurs depends on the depth of the upper oceanic mixing layer itself, which is not certain (though ARGO would suggest it is deeper than we initially thought). There is evidence to support both shorter and longer term responses.

The majority of the surface temperature response to a sudden 1W/m2 forcing would probably take place within a few years, and the initial negative energy imbalance would be less than half of what it was immediately following the change in forcing.

That's possible, but there are numerous peer reviewed studies that suggest a significantly longer response time. Not saying you're necessarily wrong, but I personally prefer a more cautious approach given this issue is far from settled.

[skierinvermont]

We already have real world examples to prove it. Temperatures dropped dramatically following Pinatubo and then warmed right back up to where they were before Pinatubo after the negative forcing dissipated. From 1993 to 1995 forcing probably increased back to what it was in 1991 pre-Pinatubo. Temperatures also rose back to what they were pre-Pinatubo. This indicates that the majority of the response both to the negative forcing when it erupted and the positive forcing when the aerosols dissipated, takes place very quickly. 

 

In addition, there is a significant temperature response to slight changes in the solar cycle. again indicating that much of the response occurs rapidly. 

 

In addition, only a small fraction of the total forcing that has occurred over the past century remains as a net energy imbalance. It could take hundreds or even thousands of years to reach complete equilibrium. But the majority of equilibrium was restored very quickly. 

 

 

The reason that if climate sensitivity is very large (>3C) the majority of warming has yet to occur is not because it takes the earth a long time get 50%+ of the way to equilibrium after a forcing. It is because positive feedbacks can continue for many centuries. 

[skierinvermont]

I'll be as simple as I can about it. 

 

Surface temperature increased nearly 1C since 1900. Unless there was an ever increasing positive radiative forcing, the net energy imbalance of the earth would have decreased by 3W/m2. So if the earth was in balance in 1900, the imbalance today would be -3W/m2 (absolutely massive). Instead it is ~+.5W/m2. 

 

I'll repeat.

 

Over the course of the 20th century, it is impossible for surface temperature and OHC to increase the way they did without an ever growing positive radiative forcing. 

 

You seem to not understand that surface temperature change alters the net energy balance of the earth.

[StudentOfClimatology]

We already have real world examples to prove it. Temperatures dropped dramatically following Pinatubo and then warmed right back up to where they were before Pinatubo after the negative forcing dissipated. From 1993 to 1995 forcing probably increased back to what it was in 1991 pre-Pinatubo. Temperatures also rose back to what they were pre-Pinatubo. This indicates that the majority of the response both to the negative forcing when it erupted and the positive forcing when the aerosols dissipated, takes place very quickly.

There was no out-of-the ordinary response in OHC after Pinatubo, using the NODC 3-month resolution.

There was a brief significant cooling at the sea surface, as would be expected, but vertical mixing always acts to dampen a temperature response at the surface. Had the SO2 aerosols theoretically remained in the the atmosphere, we would have seen a continued cooling as the mixing layer cooled.

In addition, there is a significant temperature response to slight changes in the solar cycle. again indicating that much of the response occurs rapidly.

Sure, our radiative transfer formulae cannot explain that without invoking positive feedbacks of some sort. A 1.7W/m^2 fluctuation at the TOA will be smaller at the surface, especially when it comes to solar. So I don't think you can assume TSIalone is responsible for that.

In addition, only a small fraction of the total forcing that has occurred over the past century remains as a net energy imbalance. It could take hundreds or even thousands of years to reach complete equilibrium. But the majority of equilibrium was restored very quickly.

Yes, the vast majority of peer-reviewed research suggests equilibrium is reached within the mixing layer over a window of 3-7 years, depending on it's depth. That will account for ~ 70% of the response.

The reason that if climate sensitivity is very large (>3C) the majority of warming has yet to occur is not because it takes the earth a long time get 50%+ of the way to equilibrium after a forcing. It is because positive feedbacks can continue for many centuries.

Hmm, and why would that be? After all, increasing H2O would be a consequence of temperature increase.

That's part of the reason, as is outlined in the paper.

[StudentOfClimatology]

I'll be as simple as I can about it. 

Over the course of the 20th century, it is impossible for surface temperature and OHC to increase the way they did without an ever growing positive radiative forcing.

You can't have it both ways. From 1946-1976, global temperatures dropped slightly despite increasing anthropogenic forcing, urban expansion, and an active solar component. If equilibrium were as rapid as you suggest, that should not have occurred. It can, however, be explained by an increase in oceanic mixing.