Monthly Archives: November 2006

Merger Of Air Quality Studies and Weather And Climate Research

I presented a lecture at the 2005 the Golden Jubilee of the EPA/NOAA partnership in Durham, North Carolina entitled “The Partnership of Weather and Air Quality“.

The report version of my talk

Pielke Sr. R.A., 2006: The partnership of weather and air quality – An essay. Atmospheric Science Paper No. 770, Colorado State University, Fort Collins, CO 80523, 44 pp. is now available.

The abstract reads,

“As part of the celebration of the Golden Jubilee of the EPA/NOAA partnership, this paper provides a perspective on the movement towards a merger of the disciplines of weather and air quality science. Also presented are several major conclusions regarding the modeling of atmospheric dispersion, which have resulted in the use of combined knowledge from both disciplines These conclusions include the recognition that dispersion is greater than evaluated from Gaussian models in situations with significant large scale wind flow over heterogeneous landscapes, but overestimated in light wind conditions, particularly in heterogeneous landscapes.

Methodologies are proposed that would improve the ability to model the interactions of weather and air quality. These include the replacement of existing parameterizations with much more computationally efficient look-up-tables, the calculation of the linear and nonlinear components of the models separately, and use of wind tunnel modeling to improve the accuracy of the numerical models.”

The report includes discussion on the merger of research between traditional air quality studies and climate, since atmospheric chemistry and the dispersion of natural and anthropogenic aerosols into the atmosphere are integral components of the climate system [e.g. see the 2005 National Research Council Report: Radiative forcing of climate change: Expanding the concept and addressing uncertainties].

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Documentation Of Surface Temperature Observation Sites in Mongolia

We have published a report on surface temperature observation sites in Mongolia. The report is

Jamiyansharav, K., D. Ojima, and R.A. Pielke Sr., 2006: Exposure characteristics of the Mongolian weather stations. Atmospheric Science Paper No. 779, Colorado State University, Fort Collins, CO 80523, 77 pp.

The abstract reads,

“The global average temperature anomalies are based in part on the Global Climate Observing Network (GCON) stations’ data. To insure the reliability of data, the Mongolian GCON meteorological stations’ exposure characteristics were surveyed during July-August 2005. Mongolia is a large continental region sandwiched between Russia and China at the junction of the Siberian taiga forests, Dahurian steppes, and Gobi Desert. According to the World Meteorological Organizations (WMO) guidelines, meteorological observing stations should be chosen to minimize the effects of surroundings such as trees, buildings, and other obstructions by at least 100 m radius. However, in the photo survey, some of the GCON stations did not meet the WMO standards. Therefore, the reliability of the data from these stations should be assessed and used carefully in surface temperature trend assessments. Following the WMO guidelines for GCON sites should be a priority.”

Clearly, the issue of poor siting of the long term climate observing sites is not limited to the United States.

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Evidence Of The Role Of Aerosols In Altering Regional Weather Patterns

A new Geophysical Research Letters paper has appeared which provides additional documentation on the role of aerosols in altering regional diabatic patterns, which results in significant changes in regional weather. Professor Dev Niyogi has discussed this subject on Climate Science in the posting “The Interlinked Role Of Changes In Radiative Forcings And Hydrology In The Climate System“, and alerted me to the new paper that is introduced below.

The paper by K.-M. Lau and K.-M Kim is titled
“Observational relationships between aerosol and Asian monsoon rainfall, and circulation”. (subscription required).

The abstract reads,

“Preliminary observational evidences are presented showing that the Indian subcontinent and surrounding regions are subject to heavy loading of absorbing aerosols, i.e., dust and black carbon, which possess spatial and temporal variability that are closely linked to those of the Asian monsoon water cycle. Consistent with the Elevated Heat Pump hypothesis, we find that increased loading of absorbing aerosols over the Indo-Gangetic Plain in the pre-monsoon season is associated with a) increased heating of the upper troposphere, with the formation of a warm-core upper level anticyclone over the Tibetan Plateau in April-May, b) an advance of the monsoon rainy season in northern India in May, and c) subsequent increased rainfall over the Indian subcontinent, and decreased rainfall over East Asia in June-July.”

The conclusion reads,

“Our observation results are consistent with the key features of the EHP {Elevated Heat Pump”] effect proposed by Lau et al. [2006] in showing that the anomalous high concentration of absorbing aerosol during the pre-monsoon season is associated with a) anomalous warming associated with the development of a large-scale anticyclone in the upper troposphere over the Tibetan Plateau in May and June, b) an advance of the monsoon season, with increased rainfall coming to northern India during May, and c) subsequent enhancement of the monsoon rain over India in June–July. Although the present analysis is focused on seasonal-to-interannual time scale, based on ongoing work, the relationships shown may also hold on decadal to climate change time scales reflecting the increased loading of the black carbon from anthropogenic sources in the IGB [Indo-Gangetic Basin]. Our results will provide guidance and new avenues for exploring monsoon variability and predictability. Aerosol effects on the monsoon water cycle may be important in years when influence from other controlling factors (sea surface temperature, land surface processes, and internal dynamics) are relative small, or incoherent so that they cancel out. Additionally, aerosol may have amplifying or damping effects when interacting with these factors. Therefore aerosol-monsoon water relationships have to be explored in conjunction with SST, snow cover and other agents of change in future studies.”

We discussed the importance of this climate forcing (including its relevance to the radiative forcing of the human input of CO2) in our Geophysical Research Letters paper “Measurement-based estimation of the spatial gradient of aerosol radiative forcing“. While not cited in the Lau and Kim paper, their work provides observational documentation of the importance of spatial gradients of aerosol radiative forcing.

An important issue with the new IPCC Report is whether the role of human climate forcing in regional diabatic heating of the troposphere is adequately discussed and communicated to policymakers. It was not an important issue in previous IPCC Reports.

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TV Interview “Global Warming Week: Issue politicized”.

Channel 9 in Oklahoma briefly interviewed several climate scientists (Dr. Karoly, Dr. Droegemeier, Dr. Postawko, Max Mayfield, and myself) on the issue of “Global Warming Week: Issue politicized”. The interviews can be viewed at

http://www.newsok.com/video/57000/

http://www.newsok.com/video/text/57515/?template=news/main

http://www.newsok.com/video/text/58055/?template=news/main

http://www.newsok.com/video/text/58562/?template=news/main

http://www.newsok.com/video/text/59056/?template=news/main

One interesting comment by Dr. Karoly in the second news clip is that he said in the interview that the heat island effect is a “much much smaller effect than the observed warming we have seen over the last hundred years”. Since the urban heat island effect typically results in several degrees Celsius of higher temperature than surrounding rural areas, while the global average surface temperature increase over the last hundred years is in the fraction of degrees Celsius, he is incorrect in his claim.

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A New Perspective For Assessing The Role Of Agriculture In The Climate System And In Climate Change

The published version of our paper Pielke Sr., R.A., J.O. Adegoke, T.N. Chase, C.H. Marshall, T. Matsui, and D. Niyogi, 2006: A new paradigm for assessing the role of agriculture in the climate system and in climate change. Agricultural and Forest Meteorology is ready to appear. This paper has been weblogged on Climate Science previously but it is posted today to reinforce the need for policymakers to adopt a new perspective to environmental risk.

The abstract reads,

“This paper discusses the diverse climate forcings that impact agricultural systems, and contrasts the current paradigm of using global models downscaled to agricultural areas (a top-down approach) with a new paradigm that first assesses the vulnerability of agricultural activities to the spectrum of environmental risk including climate (a bottom-up approach). To illustrate the wide spectrum of climate forcings, regional climate forcings are presented including land-use/land-cover change and the influence of aerosols on radiative and biogeochemical fluxes and cloud/precipitation processes, as well as how these effects can be teleconnected globally. Examples are presented of the vulnerability perspective, along with a small survey of the perceived drought impacts in a local area, in which a wide range of impacts for the same precipitation deficits are found. This example illustrates why agricultural assessments of risk to climate change and variability and of other environmental risks should start with a bottom-up perspective.”

An excerpt from the Conclusions reads,

“The human disturbance to the climate that influences agriculture is multi-dimensional and acts across all time scales, ranging from short-term weather events, such as damaging freezes, to seasonal average weather, such as growing season precipitation, to multi-year effects, such as in the viability of specific types of crops. This complexity makes the skillful prediction of the future climate very challenging. Currently, forecast skill beyond several months does not exist, and even on that time scale, skill is possible only for certain conditions such as a strong El Nino, as concluded in the American Association of State Climatologist policy statement on climate change and variability (http://www.ncdc.noaa.gov/oa/aasc/aascclimatepolicy.pdf).

Therefore, there is a need to adopt a new paradigm which focuses on the vulnerability of agricultural resources to the spectrum of climate change and variability threats. This approach also permits the consideration of the relative threats posed by nonclimatic environmental risks, such that policymakers can make more informed decisions as to what mitigation and/or adaptation procedures can be used to reduce the threat and increase the resiliency of the agricultural system.”

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A New Paper That Documents Biases and Uncertainties With Land Surface Temperature Trend Assessments

We have completed a new paper based on our presentation at the July 2006 Santa Fe Conference on Global Warming and the Next Ice Age.

Pielke Sr., R.A., C. Davey, D. Niyogi, K. Hubbard, X. Lin, M. Cai, Y.-K. Lim, H. Li, J. Nielsen-Gammon, K. Gallo, R. Hale, J. Angel, R. Mahmood, S. Foster, J. Steinweg-Woods, R. Boyles , S. Fall, R.T. McNider, and P. Blanken, 2006: Unresolved issues with the assessment of multi-decadal global land surface temperature trends. J. Geophys. Research, submitted.

The abstract reads,

“The paper documents various unresolved issues in using surface temperature trends as a metric for assessing global and regional climate change. A series of examples ranging from errors caused by temperature measurements at a monitoring station to the undocumented biases in the regionally and globally averaged time series are provided. The issues are poorly understood or documented and relate to micrometeorological impacts due to warm bias in nighttime minimum temperatures, poor siting of the instrumentation, effect of winds as well as surface atmospheric water vapor content on temperature trends, the quantification of uncertainties in the homogenization of surface temperature data and the influence of land use/land-cover (LULC) change on surface temperature trends.

Due to the issues presented in this paper related to the analysis of multi-decadal surface temperature we recommend that greater, more complete, documentation and quantification of these issues be required for all observation stations that are intended to be used in such assessments. This is necessary for confidence in the actual observations of surface temperature variability and long-term trends.”

The paper has several section headings,

Definition of a Global Average Surface Temperature

Difficulties with the Use of Observed Nocturnal Warming Trends as a Measure of Climate Trends

Photographic Documentation of Poor Sitings

Influence of Trends in Surface Air Water Vapor Content on Temperature Trends

Uncertainties in the Homogenization of Surface Temperature Data.

Degree of Independence of Land-Surface Global Surface Temperature Analyses

Relationship Between In-situ Surface Temperature Observations and the Diagnosis of Surface Temperature Trends from Reanalyses

Influence of Land-Use/Land-Cover Change on Surface Temperature Trends

Our conclusion states,

“This paper identified a range of issues with the use of the existing land-surface temperature data to assess multi-decadal trends in surface air temperature. Since the analyses from such data is so important in national and international assessments of climate change [e.g. see CCSP, 2006 and National Research Council, 2005, Figures 1-4 http://darwin.nap.edu/books/0309095069/html/24.html), the issues that we discuss in this paper need to be evaluated in depth……

A major conclusion is that, as a climate metric to diagnose climate system heat changes (i.e., ‘global warming’), the surface temperature trend, especially if it includes the trend in nighttime temperature, is not the most suitable climate metric. As reported in Pielke [2003] the assessment of climate heat system changes should be performed using the more robust metric of ocean heat content changes rather than surface temperature trends. If temperature trends are to be retained in order to estimate large scale (including a global) average, the maximum temperature is a more appropriate metric than using the mean daily average temperature. This paper presents reasons why the surface temperature is inadequate to determine changes in the heat content of the Earth’s climate system.”

We welcome comments on this paper. It clearly documents that the reliance of setting climate policy based on a climate metric (the global surface average temperature) which has so many remaining uncertainties is not an accurate assessment measure of multi-decadal climate change and, therefore, is an inadequate linkage between science and policy.

The type of analyses that are presented in our paper should have been included in the CCSP Report “Temperature Trends in the Lower Atmosphere: Steps for Understanding and Reconciling Differences“. Unfortunately, as I discuss in my Public Comment on CCSP Report, the CCSP Report failed to provide the appropriate beadth of perspectives that the policymakers need. That CCSP Report, therefore, is an advocacy document which promotes the narrower perspective of its authors on the subject of reconciling surface and tropospheric temperature trends. The JGR paper that we have completed should, therefore, be considered as adding information to be communicated to policymakers on the robustness of the multi-decadal surface temperature trends.

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Further Evidence for Influence of Anthropogenic Surface Processes on Lower Tropospheric And Surface Temperature Trends

A new paper has appeared in the International Journal of Climatology which provides even more evidence on the role of land surface processes in weather and climate. It is titled

“Evidence for influence of anthropogenic surface processes on lower tropospheric and surface temperature trends” and is by A. T. J. De Laat *, A. N. Maurellis
of the Netherlands Institute for Space Research (SRON) in Utrecht, Netherlands

The abstract reads,

” In de Laat and Maurellis (2004), a new framework was introduced in the form of a spatial-thresholding trend technique for analyzing the correlation between anthropogenic surface processes (e.g. changes in land use, albedo, soil moisture, groundwater levels, solar absorption by soot or energy consumption) and lower tropospheric and surface temperature trends for the period 1979-2001. In situ measured surface and satellite-measured lower tropospheric temperature trends were shown to be higher in the vicinity of industrialized regions, while such higher trends were not found in enhanced greenhouse gas (GHG) climate model simulations of temperature. It was suggested that surface and lower tropospheric temperature trends appeared to be influenced by anthropogenic non-GHG processes on the earth’s surface.

In this paper, we verify the robustness of the thresholding technique and confirm our earlier conclusions on the basis of an extended analysis and two additional data sets. We confirm the presence of a temperature change-industrialization correlation by analyzing the data with an additional statistical method and further confirm the absence of the above correlation in climate model simulations of enhanced GHG warming. Our findings thus provide an important test of climate model performance on regional scales.

These findings suggest that over the last two decades non-GHG anthropogenic processes have also contributed significantly to surface temperature changes. We identify one process that potentially could contribute to the observed temperature patterns, although there certainly may be other processes involved.”

The text includes the finding,

“These results are in agreement with the findings from Paper I and further emphasize the hypothesis that non-GHG anthropogenic processes (surface albedo, soil moisture, soot, clouds) may be involved in causing an increase in surface/lower tropospheric temperatures.”

The paper also provides support for the Christy and Spencer analysis of long term tropospheric temperature trends. The International Journal of Climatology paper reports that with respect to the sensitivity of satellite measurements to surface temperature,

“Assuming that the ABL (with a thickness of 1 km) shows a warming of 0.2 K (close to the actually observed surface warming trend) with no other atmospheric temperature trends, the satellite measurements would show a warming trend of about 0.035 and 0.01 K/decade for the MSU lower and middle tropospheric measurements respectively. Furthermore, for a warming trend of 0.2 K throughout the troposphere (height = 15 km), those numbers would be about 0.2 and 0.18 K respectively. Our simple calculation yields values for the middle and lower tropospheric temperature trends, which are comparable to what has been reported in Christy et al. (2003). But more importantly, this calculation clearly shows that measured tropospheric trends that are small can only result from free tropospheric temperature trends that are small.”

This new research provides additional issues with respect to the serious overlooked and ignored issues associated with the assessment of multi-decadal surface and tropospheric temperature trends as reported in the CCSP Report “Temperature Trends in the Lower Atmosphere: Steps for Understanding and Reconciling Differences”.

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Another Paper That Documents An Effect Of Urbanization On Weather and Climate

We have another new paper which documents the role of landscape change on weather and climate. It is

Gero, A.F., A.J. Pitman, G.T. Narisma, C. Jacobson, and R.A. Pielke Sr., 2006: The impact of land cover change on storms in the Sydney Basin. Global and Planetary Change, 54, 57-78.

The abstract reads

“This study has used a numerical model (RAMS) at 1 km horizontal grid intervals over the Sydney Basin to assess the impact of land cover change on storms. Multiple storms using the National Center for Environmental Prediction (NCEP) reanalysis data were simulated with pre-European settlement land cover then re-simulated with land cover representing Sydney’s current land use pattern. While all simulated storms did not respond to the change in land cover consistently, storms of similar types responded in comparable ways. All simulated synoptically forced storms (e.g. those triggered by cold fronts) were unresponsive to a changed land surface, while local convective storms were highly sensitive to the triggering mechanism associated with land surface influences. Storms travelling over the smoother agricultural land in the south-west of the Sydney Basin experienced an increase in velocity, and in a special case, the dense urban surface of Sydney’s city core appears to trigger an intense convective storm. It is shown that the dynamical setting predominantly triggers storm outbreaks. This is seen most clearly in the isolated convective storm category where the sea breeze front often dictates the location of storm cell initiation.

Among the conclusions is the statement that,

“The significance of the results presented here extends beyond the scope of the regional climate modeling community. This study has raised issues regarding the scale of landscape heterogeneity and the potential of sufficiently large patches of uniform land cover to contribute to storm sensitivity, as well as the potential of urban areas to enhance storms.”

This paper is yet another example of why the focus on a global averaged surface temperature trend as THE climate change metric is inadequate in terms of the actual information that policymakers need.

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Was The 2003 European Summer Heat Wave Unusual In A Global Context?

We have a new paper accepted in Geophysical Research Letters by T. N. Chase, K. Wolter, R.A. Pielke Sr., and Ichtiaque Rasool entitled “Was the 2003 European summer heat wave unusual in a global context?”

This heat wave has been attributed to human caused global warming (e.g. see and see). Our paper finds that this conclusion is not supported by an assessment of the global climate data.

The abstract reads,

“We place the European summer heat wave of 2003 in the context of other extreme temperature events since 1979 in terms of standard deviations (SD) exceeded and correlations between regional extremes and temperatures at larger spatial scales. As previously reported the heat wave was statistically unusual and was a deep tropospheric phenomenon. We find additionally that:

1) extreme warm and cold anomalies both occur regularly and occasionally exceed the magnitude of the 2003 warm anomaly.

2) There is a correlation between global and hemispheric average temperature and the presence of warm or cold regional anomalies of the same sign.

3) Natural variability in the form of El Niño and volcanic eruptions appear to be of much greater importance in causing extreme regional temperature anomalies than a simple upward trend in time.

4) Regression analyses do not support the idea that regional heat waves are increasing with time.”

As we state in our conclusion,

“We compared extreme tropospheric temperature events from 22°N to 80°N in JJA and globally using annual averages to the European summer heat wave of 2003 in terms of standard deviations exceeded and correlations between regional extremes and temperatures at larger spatial scales. As pointed out previously by Schaar et al. (2004) and Beniston (2004) the European warm anomaly during the summer of 2003 at 3.0 standard deviations was statistically unusual and was a deep tropospheric phenomenon…..”

However, we find that using the observed atmospheric data that,

“Regression analyses do not provide strong support for the idea that regional heat or cold waves are significantly increasing or decreasing with time during the period considered here (1979-2003).”

We caveat our findings in that

“As with all analyses based on short time series, the above conclusions should be viewed with caution. However, our analysis does not support the contention that similar anomalies as seen in summer 2003 are unlikely to recur without invoking a non-stationary statistical regime (Schar et al., 2004; Beniston, 2004) with a higher average temperature and increased variability.”

The answer to our question, based on the time period that we had available to analyze, “was the 2003 European summer heat wave unusual in a global context?” is NO.

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Improved Methodology For Representing Atmospheric Processes In Weather and Climate Models

Our research group has developed a concept to significantly improve the speed and realism of weather and climate model simulations. This study builds on our earlier paper that is in press in the National Weather Digest entitled “A new paradigm for parameterizations in numerical weather prediction and other atmospheric models”. The generalization of that paradigm is reported in our new study,

Pielke Sr., R.A., G. Leoncini, T. Matsui, D. Stokowski, J.-W. Wang, T. Vukicevic, C.L. Castro, D. Niyogi, C.M. Kishtawal, A. Biazar, K. Doty, R.T. McNider, U. Nair, and W.-K. Tao, 2006: Development of generalized parameterization of diabatic heating for use in weather and climate models. Atmospheric Science Paper No. 776, Colorado State University, Fort Collins, CO 80523, 15 pp.

The abstract reads

“A new approach to parameterize physical processes with weather and climate models is presented, with a specific example for diabatic heating processes. Traditionally diabatic processes within these models are parameterized separately in terms of vertical (1-D) representations of short- and longwave radiative flux divergences, stable and convective clouds and precipitation, and turbulent flux divergence. However, we propose a methodology where satellite remote-sensed data are utilized to create a unified parameterization that incorporates the net effect of each of the physical processes. This is not only computationally efficient but also implicitly includes real world three-dimensional processes. Model results are proposed along with observational analysis and simulation experiments that can provide recommendations to the remote sensing community on the types of data most useful in creating a unified parameterization of diabatic heating.”

We have submitted a shortened version of this report for publication in the peer reviewed literature.

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