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Preparing for the Next IPCC

By: Dr. Ricky Rood , 10:26 PM GMT del 13 Dicembre 2008

Preparing for the Next IPCC: This blog continues the series (linked below) where I have tried to give some visibility into the management and politics within the climate community. This one is about how the community is preparing for the next Intergovernmental Panel on Climate Change (IPCC) Report … The next report for the IPCC Working Group I, who are the physical scientists, is scheduled for release in June of 2013. In climate centers around the world, they are already configuring the models that will be used so that they can undergo extensive evaluation before they are run in IPCC experiments.

For the most part, scientific development and the community of scientists are not strongly managed. One of the big changes in the climate community, as the results of the scientific investigation take on more and more importance in society as a whole, is the need to provide “products” for particular purposes, such as the IPCC assessments. In the beginning these assessments were treated like an “add on” to the research activities that had been funded for, more or less, basic research. Today, in the U.S. there is a sub-culture of the community that is directly interested in and funded to assure the U.S> participation in IPCC. There is a constant tension between the need for basic research and the requirement to produce the products necessary for the scientific assessment of climate change. (More on that, next time. Science is managed differently in other countries.))

As suggested in the previous blogs there are a variety of ways that the community organizes to meet the need for IPCC assessments. For the next assessment, named Assessment Report 5 (AR5), it is anticipated that new types of numerical simulations will be needed. Rather than running an array of scenarios to outline what will happen, there will be more consideration of what can and will be done to stabilize the climate.

One way that the community is organizing is through a program called the Climate Model Intercomparison Project. (CMIP) . This will be CMIP number 5; hence, CMIP5. The CMIP projects follow from the Atmospheric Model Intercomparison Problem which was started in 1990. There is also an even longer history of model intercomparison and assessments in the stratospheric ozone community.

These intercomparison projects are an important part of model evaluation, but they are just part of the testing and evaluation that is done in assessing the strengths and weaknesses of models. They all have basically the same steps. Observations are the foundation of any evaluation. Hence, there is the need to identify a set of observations that will be used in the evaluations. There are hundreds of possibilities, and over the community as a whole, virtually any credible observation set that provides useful information has been used. However, there are a few that rise to stop as standard. A couple of examples are the surface temperature observations as, for example, compiled and validated and maintained by the Hadley Center and the Goddard Institute for Space Studies. Another classic example are the cloud and radiation observations that come from the Clouds and the Earth’s Radiant Energy System (CERES) instruments that fly on several satellites. (Here’s where you can get some data.)

Observations sit at the foundation, but there are several other critical elements in model evaluation. One of those critical elements is to have at least one group of independent researchers mode up of members NOT responsible for the model development. This is a group that can look at models with objectivity. In the U.S. the Program for Climate Model Diagnosis and Intercomparison is such a group. (This group is sponsored by the Department of Energy’s Office Biological and Environmental Research.)

Also critical to the process is the design of numerical experiments. (Yes, some scientists argue that there is no such thing as a “numerical experiment,” but it is possible to set up robust scientific experimentation with numerical models.) For example, in the Atmospheric Model Intercomparison Project, all of the models simulate from 1979 – 2000 using observed monthly mean sea surface temperatures. This time span was chosen because of the presence of global satellite observations. There are several standard runs in the climate model intercomparisons. An example is the “modern industrial era,” approximately the past 150 years.

Another element of the evaluation is the selection of objective measures for the evaluation and intercomparison. One of the standard measures is called the Taylor Diagram, which is an accumulation of statistical information from many data sources and many models. Here is an example of a Taylor Diagram.

Figure 1: Taylor Diagram: (primer) The plot is constructed based on the Law of Cosines. The observed field is represented by a point at unit distance from the origin along the abscissa. All other points, which represent simulated fields, are positioned such that the variance is the radial distance from the origin, the correlation is the cosine of the azimuthal angle, and the normalized root mean square difference is the distance to the observed point. When the distance to the point representing the observed field is relatively short, good agreement is found between the simulated and observed fields. In the limit of perfect agreement (which is, however, generally not achievable because there are fundamental limits to the predictability of climate), the root mean square difference would approach zero, and and correlation would approach unity.

Finally, this is an example of organizing and planning in the climate community. The process works from both the bottom and the top. Some scientists see the need for both coordination and the need to have controlled experiments across many organizations. They self organize, then seek funding from the agencies. Sometimes the agencies see the need for organization, and then offer incentives and opportunities for scientists to organize. I want to point you to an interesting document for next major IPCC assessment. This is a strategy document developed by part of the modeling community. It is an example of scientists trying to take part in the definition of the best experiments to support the assessments. Here’s A Strategy for Climate Change Stabilization Experiments with Atmospheric Ocean General Circulation Models and Earth System Models. And here are the objectives as quoted from this document.

1. Identify new components that are currently under implementation or will be ready in the next six months for inclusion as first generation Earth System Models in Atmosphere-Ocean General Circulation Models (AOGCMs).

2. Establish communication through WCRP, IGBP, IPCC, the climate impacts community, and integrated assessment (IA) modeling teams to coordinate activities in preparation for climate change simulations that will be performed with this next generation of climate system models for a possible IPCC AR5.

3. Propose an experimental design for 21st century climate change experiments with these models (near term and longer term time frames).

4. Specify the requirements for these new models in terms of time series of constituents from new stabilization scenarios (particularly with regard to impacts, mitigation, and adaptation).

Links to relevant blogs.

Importance of Justification

Buying Big Computers

Fragmented Climate

Organizing the Fragments

This series of blogs collected.

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

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93. sullivanweather
07:29 AM GMT del 21 Dicembre 2008
What's also interesting in the sea height anomaly chart is very hard to see, but a careful inspection will reveal it.

The Caspian Sea drying up...
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91. SteveBloom
05:39 AM GMT del 21 Dicembre 2008
Re #87: "Hope Yen"? :)
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90. SteveBloom
05:37 AM GMT del 21 Dicembre 2008
Re #86: I'll say it's interesting. Is this the mechanism needed for Kerry Emanuel's hypothesis that increased TC activity kept the tropics relatively cool during hotter past climate states? It sure looks like it.

BTW, that shriek heard emanating from an office down the hall from Kerry's was Dick Lindzen being bit in the butt by a bear trap. He should learn to be more careful around those things.

And isn't the A Train starting to pay off big time?
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87. presslord
04:35 PM GMT del 20 Dicembre 2008
In Science Choices, Obama Signals ChangeBy HOPE YEN, AP
(Dec. 20) - President-elect Barack Obama on Saturday named a Harvard physicist and a marine biologist to science posts, signaling a change from Bush administration policies on global warming that were criticized for putting politics over science.

Both John Holdren and Jane Lubchenco are leading experts on climate change who have advocated forceful government response. Holdren will become Obama's science adviser as director of the White House Office of Science and Technology Policy; Lubchenco will lead the National Oceanic and Atmospheric Administration, which oversees ocean and atmospheric studies and does much of the government's research on global warming.
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85. crucilandia
11:22 PM GMT del 19 Dicembre 2008
CO2 continues to lag behing temperature


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81. NRAamy
07:05 PM GMT del 19 Dicembre 2008
cb...the blog is all about geoengineering, and how it's time has come....you should be allowed to post on today's topic, for sure!

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79. crucilandia
06:47 PM GMT del 19 Dicembre 2008
If internal variability do not play a role in climate change, why they must be included in the models that project future cenarios or to understand the origing of change?

Example here

Internal variability, external forcing and climate trends in multi-decadal AGCM ensembles

Climate Dynamics, Volume 23, Number 6,

An atmospheric general circulation model of intermediate complexity is used to investigate the origin and structure of the climate change in the second half of the twentieth century. The variability of the atmospheric flow is considered as a superposition of an internal part, due to intrinsic dynamical variability, and an external part, due to the variations of the sea surface temperature (SST) forcing. The two components are identified by performing a 50-member ensemble of atmospheric simulations with prescribed, observed SSTs in the period 1949–2002. The large number of realizations allows the estimation of statistics of the atmospheric variability with a high confidence level. The analysis performed focuses on interdecadal and interannual variability of 500 hPa geopotential height in the Northern Hemisphere (NH) during winter. The model reproduces well the structure of the observed trend (defined as the difference in the two 25-year intervals 1977–2001 and 1952–1976), particularly in the Pacific region, and about half of the amplitude of the signal. The trend in 500 hPa height projects mainly onto the second empirical orthogonal function (EOF), both in the observations and in the model ensemble. However, differences between the modelled and the observed variability are found in the pattern of the second EOF in the Atlantic sector. SST changes associated with the El Niño southern oscillation (ENSO) are responsible for about 50% of the signal of the 500 hPa height trend in the Pacific. A second 50-member ensemble is used to evaluate the sensitivity of interdecadal variability to an increase in CO2 optical depth compatible with observed concentration changes. In this second experiment, the simulated trend includes a statistically significant contribution from the positive phase of the Arctic oscillation (AO). Such a contribution is also found in observations. Furthermore, the additional CO2 forcing accounts for part of the NH trend in near-surface temperature, and brings the zonal-mean temperature changes in the stratosphere and upper-troposphere closer to observations.

THE INFLUENCE OF INTERNAL VARIABILITYON CLIMATE PROJECTIONSA. Sorteberg (1), H. Drange (1,2,3), N. G. Kvamsto (1,3), T. Furevik (1,3)(1) Bjerknes Centre for Climate Research, University of Bergen, Norway, (2) NansenEnvironmental and Remote Sensing Center, Norway, (3) Geophysical Institute, University ofBergen, Norway

With identical greenhouse forcing climate models shows a wide range of responsesboth globally and regionally. This divergence from a single soulution may be partlydue todifferent model formulations and partly due to unpredicatbility of the climatesystem due to internal variability within the climate system itself. The contribution tothe total model spread from each of the two uncertainties is complex and dependenton type of climate variable, the strength of the greenhouse forcing as well as thespatial and temporal scales that are investigated.In order to estimate the contribution of the spread due to internal variability anensemble of simulations using one coupled climate model is performed. Thus theinfluence of intermodel differences on the spread is cancelled and it is possible tomake an estimate of the influence of internal variability on the climate projections.The ensemble was carried out with the coupled Bergen Climate Model (BCM) usingan atmospheric T63 truncation with 31 levels in the vertical and a variable ocean gridranging from 0.8 to 2.4 degrees and 24 vertical levels.The ensemble members have allbeen integrated with a 1% increase per year in CO2 content for 80 years, but startedin different initial ocean and atmosphere states
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78. crucilandia
06:37 PM GMT del 19 Dicembre 2008
heat content of the ocean is 10x that of the ATM. Why isn't it the other way around, the ocean is passing heat to the ATM?
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74. NRAamy
05:15 PM GMT del 19 Dicembre 2008
cb....you need to check out the Doc's blogs....your tunnels are on topic!

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70. CajunSubbie
10:10 AM GMT del 19 Dicembre 2008
CNN Meteorologist Chad Myers had never bought into the notion that man can alter the climate and the Vegas snowstorm didn’t impact his opinion. Myers, an American Meteorological Society certified meteorologist, explained on CNN’s Dec. 18 “Lou Dobbs Tonight” that the whole idea is arrogant and mankind was in danger of dying from other natural events more so than global warming.

“You know, to think that we could affect weather all that much is pretty arrogant,” Myers said. “Mother Nature is so big, the world is so big, the oceans are so big – I think we’re going to die from a lack of fresh water or we’re going to die from ocean acidification before we die from global warming, for sure.”

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69. crucilandia
06:35 AM GMT del 19 Dicembre 2008
Is global ocean circulation changes the primary mechanism driving global climate variations?
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65. SteveBloom
05:51 AM GMT del 18 Dicembre 2008
Re #64: What sort, African or European?
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64. crucilandia
05:31 AM GMT del 18 Dicembre 2008
What is the role of internal climate variations in the warming of the last century?
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58. streamtracker
08:53 PM GMT del 17 Dicembre 2008
Quoting crucilandia:

What bothers me about your posts is that you have learned nothing about the difference between short-term variability and long-term trends.

And besides where did you get that graph? Is it for global levels or is it just one gauge? Because it does not match the U.of Co. dataset.

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57. crucilandia
05:46 AM GMT del 17 Dicembre 2008
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56. SteveBloom
02:20 AM GMT del 17 Dicembre 2008
Re #54: It is. Pay attention.
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55. SteveBloom
12:05 AM GMT del 17 Dicembre 2008
Re #41: There's not necessarily a conflict between the two reports. The first one discusses glacial calving and the second overall mass loss. Among other factors, bear in mind that measurements of calving don't include meltwater loss, and that ice loss and accumulation are fairly independent processes (i.e. loss could have increased but accumulation could have increased more). Notice also that this year's calving loss was stated to be greatly dependent on a single large event late in the season, which makes me wonder if the cutoff date for the data was consistent between the two studies and if GRACE would show any difference from that big chunk of the Petermann if it hadn't moved very far.
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54. crucilandia
11:40 PM GMT del 16 Dicembre 2008
glaciers are melting, why isn't sea level rising accordingly?
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49. sullivanweather
06:42 PM GMT del 16 Dicembre 2008
Seems like 2009 is destined to follow in the footsteps of 2008...

It'll be another long year of weather event talking points to stall efforts to combat climate change and the looming energy crisis (for those of you that thought the spike in fuel prices from 2004-08 was bad, just wait).
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Dr. Ricky Rood's Climate Change Blog

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I'm a professor at U Michigan and lead a course on climate change problem solving. These articles often come from and contribute to the course.

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