Monthly Archives: August 2010

Another Paper That Documents The Complexity Of The Climate System – Vautard Et Al 2009

We have been alerted to yet another research paper that documents the complexity of the human role in the climate system (h/t to Erik). It is

Robert Vautard, Pascal Yiou and Geert Jan van Oldenborgh: 2010: Decline of fog, mist and haze in Europe over the past 30 years. Nature Geosciennces. 18 January 2009 DOI: 10.1038/NGEO414.

The abstract reads

“Surface solar radiation has undergone decadal variations since the middle of the twentieth century, producing global ‘dimming’ and ‘brightening’ effects. These variations presumably result from changes in aerosol burden and clouds3, but the detailed processes involved have yet to be determined. Over Europe, the marked solar radiation increase since the 1980s is thought to have contributed to the observed large continental warming, but this contribution has not been quantified. Here we analyse multidecadal data of horizontal visibility, and find that the frequency of low-visibility conditions such as fog, mist and haze has declined in Europe over the past 30 years, for all seasons and all visibility ranges between distances of 0 and 8 km. This decline is spatially and temporally correlated with trends in sulphur dioxide emissions, suggesting a significant contribution of air-quality improvements. Statistically linking local visibility changes with temperature variations, we estimate that the reduction in low-visibility conditions could have contributed on average to about 10–20% of Europe’s recent daytime warming and to about 50% of eastern European warming. Large improvements in air quality and visibility already achieved in Europe over the past decades may mean that future reductions in the frequency of low-visibility events will be limited, possibly leading to less rapid regional warming.”

Text in the conclusion reads

“Unfortunately, current regional climate models are probably not ready to reproduce the physics underlying these trends, because a fully integrated representation of the atmosphere, with surface processes, microphysics coupled with aerosols and gasphase chemistry models, with relatively high resolution, is required. Also required are databases of the long-term evolution of land use, anthropogenic heat fluxes, aerosol anthropogenic and natural gas species and aerosol emissions. As yet, state-of-the-art regional aerosol models have been shown not to be able to simulate with sufficient skill the total aerosol burden over Europe. Simulating trends in low-visibility phenomena, and their impact on climate, therefore remains an open challenge for models.”

This paper documents a particular major role of aerosols in regional climate, and also the inability of current climate models to skillfully simulate (much less predict) this effect.

Comments Off

Filed under Climate Change Forcings & Feedbacks, Research Papers

Release Of The Report “Climate Change Assessments, Review of the Processes & Procedures of the IPCC”

The report “Climate Change Assessments, Review of the Processes & Procedures of the IPCC”  has been released today. An initial discussion of the report is posted at

Report of the IAC Review of the IPCC

The news media are reporting on this and CNN’s report “U.N. climate body needs ‘fundamental reform'”  presents an effective single statement of what is needed for future assessments (i.e. a fundamental reform].

There remain conflicting conclusions in the IAC report, however, such as the finding that

“The Committee concludes that the IPCC assessment process has been successful overall and has served society well.”

The IAC report expands on this statement in their following text to the above sentence where they write

“The commitment of many thousands of the world’s leading scientists and other experts to the assessment process and to the communication of the nature of our understanding of the changing climate, its impacts, and possible adaptation and mitigation strategies is a considerable achievement in its own right. Similarly, the sustained commitment of governments to the process and their buy-in to the results is a mark of a successful assessment. Through its unique partnership between scientists and governments, the IPCC has heightened public awareness of climate change, raised the level of scientific debate, and influenced the science agendas of many nations. However, despite these successes, some fundamental changes to the process and the management structure are essential, as discussed in this report and summarized below.”

If their assessment process really “has been successful overall and has served society well”, however, there would be no need for the recommendation that “fundamental changes to the process and the management structure are essential“.

Nonetheless, despite this one inconsistency, the report recommendations are very insightful and valuable.

The deficiencies of past assessment, including that of the 2007 IPCC report, have been documented in depth on my weblog as well as by others (e.g. see , see and see). I have discussed the serious flaws in the IPCC process, for example, in weblog posts, testimony and public statements: 

Pielke Sr., Roger A., 2005: Public Comment on CCSP Report “Temperature Trends in the Lower Atmosphere: Steps for Understanding and Reconciling Differences”. 88 pp including appendices.

Pielke Sr., Roger A., 2008: A Broader View of the Role of Humans in the Climate System is Required In the Assessment of Costs and Benefits of Effective Climate Policy. Written Testimony for the Subcommittee on Energy and Air Quality of the Committee on Energy and Commerce Hearing “Climate Change: Costs of Inaction” – Honorable Rick Boucher, Chairman. June 26, 2008, Washington, DC., 52 pp.

E-mail Documentation Of The Successful Attempt By Thomas Karl Director Of the U.S. National Climate Data Center To Suppress Biases and Uncertainties In the Assessment Surface Temperature Trends.

My concerns were summarized in  the submission of comments as part of the IAC review process; see

My Comments For The InterAcademy Council Review of the IPCC

The recognition of the serious conflict of interest associated with the IPCC process is refreshing, and hopefully, will be built on in order to finally obtain inclusive, balanced climate science assessments.

Comments Off

Filed under Climate Science Reporting

New Paper On Climate Variability and Trends In The Southwest USA By McCabe Et Al 2010

There is a very interesting new paper with respect to climate trends in the southwestern United States (h/t to ICECAP and World Climate Report ). It is

McCabe, G. J., D. R. Legates, and H. F. Lins. 2010. Variability and trends in dry day frequency and dry event length in the southwestern United States, Journal of Geophysical Research, 115, D07108, doi:10.1029/2009JD012866.

The abstract reads

“Daily precipitation from 22 National Weather Service first‐order weather stations in the southwestern United States for water years 1951 through 2006 are used to examine variability and trends in the frequency of dry days and dry event length. Dry events with minimum thresholds of 10 and 20 consecutive days of precipitation with less than 2.54 mm are analyzed. For water years and cool seasons (October through March), most sites indicate negative trends in dry event length (i.e., dry event durations are becoming shorter). For the warm season (April through September), most sites also indicate negative trends; however, more sites indicate positive trends in dry event length for the warm season than for water years or cool seasons. The larger number of sites indicating positive trends in dry event length during the warm season is due to a series of dry warm seasons near the end of the 20th century and the beginning of the 21st century. Overall, a large portion of the variability in dry event length is attributable to variability of the El Niño–Southern Oscillation, especially for water years and cool seasons. Our results are consistent with analyses of trends in discharge for sites in the southwestern United States, an increased frequency in El Niño events, and positive trends in precipitation in the southwestern United States.”

The conclusion contains the text

Little evidence of long‐term positive trends in dry event length in the southwestern United States is apparent in the analysis of daily WBAN precipitation data. During the mid‐1990s to late 1990s, drought conditions began in the southwestern United States and persisted in the 21st century. This drought has resulted in positive trends in dry event length for some sites in the southwestern United States. However, most of the statistically significant trends in the number of dry days and dry event length are negative trends for water years and cool seasons.

In addition, correlation and spectral analyses indicate that a substantial portion of the variability in dry event characteristics in the southwestern United States is attributable to ENSO variability, particularly for water years and cool seasons. Since the mid‐1970s, El Niño events have been more frequent, and this has resulted in increased precipitation in the southwestern United States, particularly during the cool season. The increased precipitation is associated with a decrease in the number of dry days and a decrease in dry event length.

This paper reinforces two issues that have repeatedly been made on my weblog:

and

  • The dominance of the regional climate feature of ENSO, as reported in the McNabe et al 2010 paper, further documents why the use of a global average surface temperature trend (or global average radiative forcing) is a grossly inadequate metric to diagnose climate variability and change.

Comments Off

Filed under Climate Change Forcings & Feedbacks, Research Papers

Article In Nature “Cold Empties Bolivian Rivers Of Fish” By Anna Petherick

Nature has published an excellent news article by Anna Petherick [h/t to Dan Hughes for alerting us!]

Cold empties Bolivian rivers of fish

which illustrates that even when the global average surface temperature is above average (for whatever reason) regional cold waves can occur which have major environmental consequences.

The article starts with the text

“With high Andean peaks and a humid tropical forest, Bolivia is a country of ecological extremes. But during the Southern Hemisphere’s recent winter, unusually low temperatures in part of the country’s tropical region hit freshwater species hard, killing an estimated 6 million fish and thousands of alligators, turtles and river dolphins.’

and includes the text

Water temperatures in Bolivian rivers that normally register about 15 ˚C during the day fell to as low as 4 ˚C.

Hugo Mamani, head of forecasting at Senamhi, Bolivia’s national weather centre, confirms that the air temperature in the city of Santa Cruz fell to 4 ˚C this July, a low beaten only by a record of 2.5 ˚C in 1955.

This extreme event also further illustrates why a bottom-up, resource-based perspective (in this case on ecological function on the regional scale) as presented in

A Way Forward In Climate Science Based On A Bottom-Up Resourse-Based Perspective

is needed.

Comments Off

Filed under Climate Science Reporting, Vulnerability Paradigm

A Western Governer’s Association Meeting – “Drought, Water, and Climate: Using Today’s Information To Design Tomorrow’s Services”

I have been alerted to a meeting on climate in mid-September.  It is

Drought, Water, and Climate: Using today’s information to design tomorrow’s services. Washington DC September 14‐15, 2010 [registration is at http://www.surveymonkey.com/s/2VCLY2M]

The meeting is sponsored by the Western Governor’s Association with several Governer’s giving presentations.

The information on the meeting is listed below.  An examination of the Agenda shows that while a number of interesting talks will be presented by excellent climate scientists, it does not appear that a bottom-up resource-based perspective is being adopted by this community as recommended in

A Way Forward In Climate Science Based On A Bottom-Up Resourse-Based Perspective

With respect to water resources, the following are the questions they should be focusing on

 
1. What are the key environmental and social variables that influence water resources?
 
3.  What is the sensitivity of water resources to changes in each of these key variables? (this includes, but is not limited to, the sensitivity of water resources to climate variations and change on short (e.g. days); medium (e.g. seasons) and long (e.g. multi-decadal) time scales.
 
4. What changes (thresholds) in these key variables would have to occur to result in a negative (or positive) response to water resources?
 
5. What are the best estimates of the probabilities for these changes to occur? What tools are available to quantify the effect of these changes. Can these estimates be skillfully predicted?
 
6. What actions (adaptation/mitigation) can be undertaken in order to minimize or eliminate the negative consequences of these changes (or to optimize a positive response)?

7. What  are specific recommendations  for policymakers and other stakeholders?

The meeting information follows:

LOGISTICS:  This will be a two-day workshop at the Grand Hyatt in Washington, D.C.  Space is limited so please register early.  Registration at:  http://www.surveymonkey.com/s/2VCLY2M

 PURPOSE:  Over the last two years, the Western Governors’ Association and Western States Water Council have worked with a diverse group of federal, tribal, state, and local partners from the public and private sectors to solicit decision-makers’ priority needs for drought and water information. This meeting will focus particular attention on coordinating drought and related climate services and response among federal agencies and at federal, state, tribal, and non-governmental intersections in order to meet priority needs.   The goal is to develop a set of specific recommendations to improve drought information coordination, delivery, and response in a changing environment.   

 TOPICS:

  • The sectoral impacts of drought and climate change
  • The need for and urgency of drought and climate response
  • Existing and emerging drought and climate services and response programs
  • Delivering drought and climate services to end users
  • Investing in basic data and forecasts
  • Revisiting a national drought policy
  • Specific recommendations and activities to strengthen drought response and services

 AUDIENCE:  The audience for this workshop includes water, climate, and drought-related program managers, policy-makers, and budget analysts; strategic planners; federal-tribal-state-local partnership coordinators; water managers; drought & climate service-related researchers and academics; and interested NGO and private sector participants.

SPEAKERS:  Invited speakers include Colorado Governor Bill Ritter, NOAA Administrator Jane Lubchenco, Representative Grace Napolitano, and state, federal, NGO, and academic drought and climate experts.

The talks and breakout sessions (as of the August 20th draft agenda) include

Keynote: Water and Climate in the West Governor Bill Ritter, Colorado (invited)

Water: The Nation’s Fundamental Climate Issue Anne Castle or John Tubbs, DOI Water and Science (invited)

Drought Policy and Planning – National and International Perspectives Don Willhite, School of Natural Resources, University of Nebraska

Drought and Climate – State of the Science Richard Seager, Lamont‐Doherty Earth Observatory of Columbia University

WGA – Climate Adaptation and Drought Brian Turner, Office of Governor Arnold Schwarzenegger, California

National Integrated Drought Information System Roger Pulwarty, Director, NOAA/NIDIS

Regional Meetings – What we’ve learned to date. Tom Iseman, WGA & Tony Willardson, WSWC

Lunch Keynote: NOAA Climate Services Jane Lubchenco, NOAA Administrator

Drought Impacts and Preparedness – Panel I Veva Deheza – State of Colorado
Carol Couch – State of Georgia Rueben Solis – State of Texas Kirk Bemis – Zuni Tribe

Drought Impacts and Preparedness – Panel II Carol Collier – Delaware River Basin Commission Andrew Fahlund, American Rivers Tom Donnelly, National Water Resources Association (invited) Floyd Wicks, Former CEO, American States Water Company (invited)

Breakout Group – Drought Impacts, Preparedness, and Adaptation
What are the impacts of drought to different sectors, including socio‐economic impacts, and how do we track and report them? What are best practices for preparing for drought and climate change?

NIDIS: Regional Drought Early Warning Systems Jim Verdin, USGS/NIDIS Roger Pulwarty, NOAA/NIDIS

NIDIS: The U.S. Drought Portal Mike Brewer, NOAA/NIDIS Mark Svoboda, National Drought Mitigation Center/NIDIS

Breakout Group – Delivering Drought Information Services How do we ensure priority services are delivered on‐the‐ground? How do we know that drought and climate services are meeting user needs?

Federal Agencies: Coordinating Federal Climate Services for Drought and Water Loren Labovitch, CEQ, Moderator Panel Discussion: NOAA, USDOI, USDA, USFS, EPA, COE

Lunch Keynote: Drought and Climate in Congress – Representative Grace Napolitano (invited)

National Drought Policy and Climate Risk Management Don Willhite, University of Nebraska, Moderator Panel Discussion: NGA, Congressional Staff, OSTP

Breakout Groups: Next steps to ensure that priority services are delivered to on‐the‐ground users.

I will post a summary of the meeting if it becomes available. If so, we can then assess whether the Western Governors  accept a narrow top-down IPCC model driven perspective as contrasted with the more inclusive bottom-up water resource based viewpoint.

Comments Off

Filed under Climate Science Meetings, Vulnerability Paradigm

Another Human And Natural Climate Forcing – Pyrocumulonimbus Storms

As we learn more about the climate system, we continue to discover additional humans and natural climate forcings occur. The August 17 2010 issue of EOS has an excellent article by Randy Showstack titled

Researchers Focus on Fire Clouds That Reach to the Stratosphere

which reports on such a climate forcing.  Excerpts from the paper read

“Volcanic eruptions are not the only violent events that can inject smoke-colored and cauliflower-textured clouds into the stratosphere. Pyrocumulonimbus (pyroCB) storms can, too. These recently discovered phenomena are storms caused or aided by fire; they have many characteristics similar to thunderstorms, including lightning, hail, and extreme vertical height through the troposphere and into the lower stratosphere.”

“Common wisdom had held that “the only event that can explosively pollute the stratosphere is a volcanic eruption,” Michael Fromm, a meteorologist with the Naval Research Laboratory in Washington, D. C., said at a 9 August press briefing at the 2010 Meeting of the Americas in Foz do Iguaçu, Brazil. “Now we know that pyroCBs can do a version of this, thanks to the heat from fire.” Fromm is a coauthor of “The untold story of pyrocumulonimbus,” a paper to be published in the Bulletin of the American Meteorological Society.”

“The paper states that these events occur “surprisingly frequently”—with 17 now known to have occurred in Canada and the United States in 2002 alone…”

“Fromm said pyroCBs have a volcano-like impact on the stratosphere, injecting material ‘far enough into the stratosphere that particles and gases can remain for months.’”

“While volcanoes can affect global temperature because of the mass of stratospheric aerosols that can be created from some eruptions, Fromm explained that pyroCB events cannot compete with the biggest eruptions. He added that repeated smaller contributions of aerosols from pyroCBs “may be something that we need to pay attention to.”

The sources of these fires are from both natural events (e.g. a forest fire from lightning) and from human caused events (e.g. biomass burning for land clearing).  The recognition that the aerosols associated with these thunderstorms can be ejected into the stratosphere and persist there for months clearly shows that pyrocumulonimbus have a significant climate effect both on the regional and global scales.

Comments Off

Filed under Climate Change Forcings & Feedbacks

Comments On The Economist Article “Green View: Could Temperature Be Less Intemperate?”

I was queried on Monday of this week by the Economist regarding the September Exeter meeting regarding the project surfacetemperatures.org which I posted on in

Meeting September 7-9 2010 “Surface Temperature Datasets For The 21st Century” Chaired By Peter Thorne

My comment to the Economist when asked

I wondered what you thought of the surfacetemperatures.org project/plan of action. I know you objected to some of what Peters Thorne and Stott said in their piece in nature about current surface temperature records, but I wondered what you thought of their ideas for making things better in the future.

My response was

 In terms of monitoring global warming, the successful installation of an upper ocean heat monitoring system which has been in place since earlier this decade (Argo as complemented with satellite measurements of the ocean) supersedes the need to use the surface air temperature data as the primary metric for this purpose [as I summarize in my article

Pielke Sr., R.A., 2008: A broader view of the role of humans in the climate system. Physics Today, 61, Vol. 11, 54-55. http://pielkeclimatesci.files.wordpress.com/2009/10/r-334.pdf].

We can obtain a much more robust measure of global warming (and cooling) by monitoring the upper ocean heat changes.

In terms of improving the surface temperature data (which is, of course, needed for a variety of other purposes such as agriculture, recreation, etc), the goal to improve the access and audit of the data is commendable.

However, they seem to be ignoring known (i.e peer reviewed published) problems with this data. There is, for example, a need to photograph the sites and to seek past photos of these locations in order to see how well they are sited.

They also appear not to be considering other issues that we raised in the papers that I posted on this morning. This includes the warm bias we have found in the minimum land surface temperatures that are used in their construction of a land average temperature trend, and the need to include the effect of concurrent surface air, water vapor trends on the surface air heat (i.e. its moist enthalpy).

There are also issues with the “homogenization” of the data which they use to create grid area averages. When poor- and well-site locations are blended together, for instance, the result appears to be biasing the results [a subject we will be presenting in a paper that is almost complete]. The quantitative steps in their homogenization adjustment needs further scrutiny and it is not clear they will be doing this.

Please let me know if you need further feedback.

Best Regards

The article has now appeared [August 25 2010]

Green View: Could Temperature Be Less Intemperate?

 and my response to it is given below.

 Thank you for sending. With respect to adding comments on their weblog surfacetemperatures.org, Peter Thorne and colleagues already have seen the issues that we have raised in the set of peer reviewed papers that we have published on this topic; e.g. e.g.

Pielke Sr., R.A., C. Davey, D. Niyogi, S. Fall, J. Steinweg-Woods, K. Hubbard, X. Lin, M. Cai, Y.-K. Lim, H. Li, J. Nielsen-Gammon, K. Gallo, R. Hale, R. Mahmood, S. Foster, R.T. McNider, and P. Blanken, 2007: Unresolved issues with the assessment of multi-decadal global land surface temperature trends. J. Geophys. Res., 112, D24S08, doi:10.1029/2006JD008229.
http://pielkeclimatesci.files.wordpress.com/2009/10/r-321.pdf

Pielke Sr., R.A., C. Davey, D. Niyogi, S. Fall, J. Steinweg-Woods, K. Hubbard, X. Lin, M. Cai, Y.-K. Lim, H. Li, J. Nielsen-Gammon, K. Gallo, R. Hale, R. Mahmood, S. Foster, R.T. McNider, and P. Blanken, 2009: Reply to comment by David E. Parker, Phil Jones, Thomas C. Peterson, and John Kennedy on .Unresolved issues with the assessment of multi-decadal global land surface temperature trends. J. Geophys. Res., 114, D05105,
doi:10.1029/2008JD010938.
http://pielkeclimatesci.files.wordpress.com/2009/10/r-321a.pdf

[and see the reviews of the above Comment/Reply of Parker et al where the referees agreed with our Reply – http://pielkeclimatesci.wordpress.com/2009/01/23/reply-by-pielke-et-al-to-the-comment-by-parker-et-al-on-our-2007-jgr-paper-unresolved-issues-with-the-assessment-of-multi-decadal-global-land-surface-temperature-trends/.

Klotzbach, P.J., R.A. Pielke Sr., R.A. Pielke Jr., J.R. Christy, and R.T. McNider, 2009: An alternative explanation for differential temperature trends at the surface and in the lower troposphere. J. Geophys. Res., 114, D21102, doi:10.1029/2009JD011841.

Klotzbach, P.J., R.A. Pielke Sr., R.A. Pielke Jr., J.R. Christy, and R.T. McNider, 2010: Correction to: “An alternative explanation for differential temperature trends at the surface and in the lower troposphere. J. Geophys. Res., 114, D21102, doi:10.1029/2009JD011841″, J. Geophys. Res., 115, D1, doi:10.1029/2009JD013655
 

Indeed, Peter Thorne has a documented history of suppressing other viewpoints as I have documented with e-mails and in a Public Comment; i.e

http://pielkeclimatesci.wordpress.com/2009/11/26/e-mail-documentation-of-the-successful-attempt-by-thomas-karl-director-of-the-u-s-national-climate-data-center-to-suppress-biases-and-uncertainties-in-the-assessment-surface-temperature-trends/

Pielke, R.A. Sr., 2005: Public Comment on CCSP Report “Temperature Trends in the Lower Atmosphere: Steps for Understanding and Reconciling Differences”. 88 pp including appendices.
http://pielkeclimatesci.files.wordpress.com/2009/09/nr-143.pdf

I agree with Anthony Watts that “[a]pprised of it, he says that while ‘a noble effort, it is a reaction to a series of data transparency blunders rather than a proactive approach to open replication.'”

I would also add, that despite the significant involvement of myself and my colleagues in assessing uncertainties and biases with respect to the land surface temperature record in the peer reviewed literature, we were not invited to the Exeter meeting.

For these reasons, I disagree with your statement

“So, while Dr Thorne and his colleagues try to do something that is both difficult and worthwhile in a way that increases transparency, critics outside the community have to date more or less ignored the opportunity to get involved.”

We have very much been involved and Peter Thorne and his associates continue to fail at being inclusive. This meeting looks like “business as usual.

Best Regards

Roger Sr.

Comments Off

Filed under Climate Change Metrics, Climate Science Reporting

New Paper On The Role Of The Long Range Transport Of Mineral Dust And Other Aerosols By Ben-Ami Et Al 2010

In our paper

Pielke Sr., R., K. Beven, G. Brasseur, J. Calvert, M. Chahine, R. Dickerson, D. Entekhabi, E. Foufoula-Georgiou, H. Gupta, V. Gupta, W. Krajewski, E. Philip Krider, W. K.M. Lau, J. McDonnell,  W. Rossow,  J. Schaake, J. Smith, S. Sorooshian,  and E. Wood, 2009: Climate change: The need to consider human forcings besides greenhouse gases. Eos, Vol. 90, No. 45, 10 November 2009, 413. Copyright (2009) American Geophysical Union.

we presented evidence that the human role on the climate system is much broader than just that from the addition of carbon dioxide and other greenhouse gases to the atmosphere.

There is a new paper that provides further evidence of the role of aerosols (which in this study is a combination of natural and human effects) on the climate system. The paper also documents how this effect is transported across thousands of kilometers. This new research further confirms what was concluded in

National Research Council, 2005: Radiative forcing of climate change: Expanding the concept and addressing uncertainties. Committee on Radiative Forcing Effects on Climate Change, Climate Research Committee, Board on Atmospheric Sciences and Climate, Division on Earth and Life Studies, The National Academies Press, Washington, D.C., 208 pp

that

“Several types of forcings—most notably aerosols, land-use and land-cover change, and modifications to biogeochemistry—impact the climate system in nonradiative ways, in particular by modifying the hydrological cycle and vegetation dynamics. Aerosols exert a forcing on the hydrological cycle by modifying cloud condensation nuclei, ice nuclei, precipitation efficiency, and the ratio between solar direct and diffuse radiation received.

The paper is

Ben-Ami, Y., Koren, I., Rudich, Y., Artaxo, P., Martin, S. T., and Andreae, M. O. 2010: Transport of North African dust from the Bodélé depression to the Amazon Basin: a case study, Atmos. Chem. Phys., 10, 7533-7544, doi:10.5194/acp-10-7533-2010

with the abstract

“Through long-range transport of dust, the North-African desert supplies essential minerals to the Amazon rain forest. Since North African dust reaches South America mostly during the Northern Hemisphere winter, the dust sources active during winter are the main contributors to the forest. Given that the Bodélé depression area in southwestern Chad is the main winter dust source, a close link is expected between the Bodélé emission patterns and volumes and the mineral supply flux to the Amazon.

Until now, the particular link between the Bodélé and the Amazon forest was based on sparse satellite measurements and modeling studies. In this study, we combine a detailed analysis of space-borne and ground data with reanalysis model data and surface measurements taken in the central Amazon during the Amazonian Aerosol Characterization Experiment (AMAZE-08) in order to explore the validity and the nature of the proposed link between the Bodélé depression and the Amazon forest.

This case study follows the dust events of 11–16 and 18–27 February 2008, from the emission in the Bodélé over West Africa (most likely with contribution from other dust sources in the region) the crossing of the Atlantic Ocean, to the observed effects above the Amazon canopy about 10 days after the emission. The dust was lifted by surface winds stronger than 14 m s−1, usually starting early in the morning. The lofted dust, mixed with biomass burning aerosols over Nigeria, was transported over the Atlantic Ocean, and arrived over the South American continent. The top of the aerosol layer reached above 3 km, and the bottom merged with the boundary layer. The arrival of the dusty air parcel over the Amazon forest increased the average concentration of aerosol crustal elements by an order of magnitude.”

As the climate system is investigated further, the shortcomings and incompleteness of the 2007 IPCC WG1 report become increasingly evident.

Comments Off

Filed under Climate Change Forcings & Feedbacks, Research Papers

Futher Information On Tree Ring Proxy Data – A Research Paper García-Suárez Et Al 2009

In response to the post

Comment On Tree Ring Proxy Data and Thermometer Type Surface Temperature Anomalies And Trends

we have been alerted to an interesting paper on tree ring proxy data (h/t to Erik W!).

The paper is

García-Suárez et al, 2009: Climate signal in tree-ring chronologies in a temperate climate: A multi-species approach. Dendrochronologia 27 (2009)183–198

and the abstract reads

“Tree-rings can provide continuous yearly paleoclimatic records for regions or periods of time with no instrumental climate data. However, different species respond to different climate parameters with, for example, some sensitive to moisture and others to temperature. Here, we describe four common species growing in Northern Ireland and their suitability for climate reconstruction.

Our results suggest that beech and ash are the most sensitive to climate, with tree-ring widths more strongly influenced by precipitation and soil moisture in early summer than by temperature or sunshine. Oak is also sensitive to summer rainfall, whereas Scots pine is sensitive to maximum temperature and the soil temperature.

 We find that the moisture-related parameters, rainfall and the Palmer Drought Severity Index (PDSI), and to a lesser extent, maximum and mean temperatures, can be reconstructed. Reconstructions of climate parameters with tree-rings as proxies may be relatively stable for some seasons such as May–July. We find that combinations of species are more successful in reconstructing climate than single species.”

The conclusion has the text

“When reconstructing past climate from tree-rings (e.g. the amplitude of the Little Ice Age or Medieval Warm Period), it is important to appreciate that these reconstructions are conservative as they only contain a part of the true climate signal.”

Comments Off

Filed under Climate Change Metrics, Research Papers

Comments On A Seminar “Modeling Watershed-Scale Distributions Of Snow For Present-Day And Future Climate” By Anne Nolin

There is a seminar today [August 23 2010] by Anne Nolin of the Department of Geosciences,  at Oregon State University, Corvallis

The seminar is titled “Modeling Watershed-Scale Distributions of Snow for Present-day and Future Climate in the U.S. Pacific Northwest Monday, 23 August 2010, 2:00 PM David Skaggs Research Center, Room 1D403.

After I present the abstract, I give several comments on this study, which is just one example of a type of climate study that has become common in recent years (i.e. one based on (unverifiable) multi-decadal global climate predictions).

The abstract reads

The snowmelt-dominated Cascade Mountains provide critical water supply for agriculture, hydropower, ecosystems, and municipalities throughout the Pacific Northwest. Empirical analyses and models of projected climate change show rising temperatures in the region. This temperature trend is accompanied by a shift from snowfall to rainfall at lower elevations and earlier snowmelt. In this study we model the spatial distribution of Snow Water Equivalent (SWE) in the McKenzie River Basin, Oregon (3000 km2). We use the physically based SnowModel with a grid resolution of 100 m and a daily time step. Model inputs include meteorological data, a digital elevation model, and land cover information. We compute the ratio of SWE to total winter precipitation (SWE/PRE) for the period of 2000-2009. The model is evaluated using point-based measurements of SWE, precipitation, and temperature and spatially, using snow cover extent from the MODIS instrument. SnowModel simulations are in very good agreement with measured SWE for most stations with Nash-Sutcliffe model efficiency values exceeding 0.9 in most cases. Agreement with MODIS snow cover data show a total difference of 7.1% at the time of peak SWE with the largest difference in valley bottoms (where vegetation is dense and snow cover is difficult to view with the satellite data).

For the future climate scenarios, meteorological inputs are perturbed based upon downscaled Intergovernmental Panel on Climate Change model predictions. The temperature and precipitation forcing data for 2000-2009 were perturbed to represent projected climate changes based on a composite of nineteen IPCC climate models (scenario A1B) downscaled to the Pacific Northwest region for the period 2030-2050. These perturbations were computed using the change from present-day climate to a projected future climate (delta value). The delta value was applied to daily temperature and precipitation data using a prescribed monthly value and the model was rerun using these perturbed values. Our perturbed simulations show substantial losses in SWE throughout the watershed. However, interannual variability under projected climate change can generate increases in SWE at high elevations but overall declines in basin-wide SWE. Thus, while there is a significant loss of snow covered area and volumetric water storage in the form of snow, the spatial changes in SWE are highly heterogeneous. This has important implications for runoff predictions as well as for design and implementation of snow monitoring networks.”

Here are my comments:

1. Her  evaluation of the snow distributions for the period 2000-2009 is solid science.

2. The extrapolation into the future using IPCC model predictions downscaled to the region of study, however, is not scientifically sound. First, even with current climate, the global climate models have shown no skill at predicting regional skill more than a season at most into the future. These global models are not able to skillfully simulate such regional circulation patterns as the Pacific Decadal Oscillation and ENSO, which are known to have a major effect on the weather in Oregon.

3. The packaging of her results in time periods (i.e. 2030-2050) is inappropriate and misleading to policymakers. 

4. Such unverifiable multi-decadal predictions based on the IPCC global models (as exemplified by this seminar) are  being supported by the NSF and other agencies, and are being published in the literature. Such studies, where the results are presented as forecasts rather than climate process studies,  were not funded before the last 10-15 years or so.

5. My recommended approach is to adopt the perspective that is summarized in the post

A Way Forward In Climate Science Based On A Bottom-Up Resourse-Based Perspective

where with respect to water resources the framework would read

“The vulnerability concept requires the determination of the major threats to water resources from climate, but also from other social and environmental issues. After these threats are identified for each resource, then the relative risk from natural- and human-caused climate change (estimated from the GCM projections, but also the historical, paleo-record and worst case sequences of events) can be compared with other risks in order to adopt the optimal mitigation/adaptation strategy.”

This is a much more inclusive approach than the limited narrowly focused approach presented in the second part of Anne Nolin’s seminar.

Comments Off

Filed under Climate Science Misconceptions, Climate Science Presentations