Download Land-Use Change and Microclimate Exposure Effects on Near-Surface Air Temperature Assessments:

Land-Use Change and
Microclimate Exposure Effects on
Near-Surface
Air Temperature Assessments:
Unresolved Issues
Prof. Roger A. Pielke Sr.
University of Colorado, CIRES, Boulder,
Detecting the Atmospheric Response to the Changing Face of
the Earth: A Focus on Human-Caused Regional Climate
Forcings, Land-Cover/Land-Use Change, and Data Monitoring
August 27-29, 2007 Boulder CO
The CCSP Report "Temperature Trends in the
Lower Atmosphere: Steps for Understanding
and Reconciling Differences" inadequately
reported on these issues
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.
http://climatesci.colorado.edu/publications/pdf/NR-143.pdf
Specific Questions Not
Investigated in the CCSP Report
Æ What is the bias in degrees Celsius introduced as a result of
aggregating temperature data from different measurement heights,
aerodynamic roughnesses, and thermodynamic stability?
Æ What is the quantitative uncertainty in degrees Celsius that are
associated with each of the steps in the homogenization of the surface
temperature data?
Æ What is the overlap in the raw data that utilized by the three groups?
Æ What is the value-added of using annually-averaged surface
temperatures to assess global climate system heat changes ("global
warming") over the last several decades in lieu of assessing the
regional, zonally-average and global trends in ocean, and other
climate component heat storage in units of Joules?
Examples Of Overview Papers On
The Robustness of Land-Surface
Temperature Network
¾ Mahmood, Rezaul , Stuart A. Foster and David Logan, 2006: The
Geoprofile metadata, exposure of instruments, and measurement bias
in climatic record revisited International Journal of Climatology
http://www3.interscience.wiley.com/
¾ Pielke Sr., R.A. J. Nielsen-Gammon, C. Davey, J. Angel, O. Bliss, N.
Doesken, M. Cai., S. Fall, D. Niyogi, K. Gallo, R. Hale, K.G. Hubbard, X.
Lin, H. Li, and S. Raman, 2007: Documentation of uncertainties and
biases associated with surface temperature measurement sites for
climate change assessment. Bull. Amer. Meteor. Soc., 88:6, 913-928.
http://climatesci.colorado.edu/publications/pdf/R-318.pdf
¾ 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. in press.
http://climatesci.colorado.edu/publications/pdf/R-321.pdf
How spatially representative is
each surface observing site?
Fort Morgan site showing images of the cardinal directions from the sensor (from
Hanamean et al. 2003). http://climatesci.colorado.edu/publications/pdf/R-254.pdf
Photographs of the temperature sensor exposure characteristics of the NWS COOP
station at Las Animas, CO. Panel a) shows the temperature sensor, while panels b)-e)
illustrate the exposures viewed from the sensor looking N, E, S, and W, respectively. From
Davey, C.A., and R.A. Pielke Sr., 2005: Microclimate exposures of surface-based weather
stations - implications for the assessment of long-term temperature trends. Bull. Amer.
Meteor. Soc., 4, 497–504. http://climatesci.colorado.edu/publications/pdf/R-274.pdf
http://www.climateaudit.com/
http://www.surfacestations.org/
We need to extend this
assessment worldwide!
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, 75 pp.
http://climatesci.colorado.edu/publications/pdf/NR-145.pdf
Do surface sites adequately
measure heat?
™ Pielke Sr., R.A., C. Davey, and J. Morgan, 2004: Assessing
"global warming" with surface heat content. Eos, 85, No. 21,
210-211.
http://climatesci.colorado.edu/publications/pdf/R-290.pdf
™ Pielke, R.A. Sr., K. Wolter, O. Bliss, N. Doesken, and B.
McNoldy, 2006: The July 2005 Denver heat wave: How unusual
was it? Nat. Wea. Dig., accepted.
http://climatesci.colorado.edu/publications/pdf/R-313.pdf
™ Davey, C.A., R.A. Pielke Sr., and K.P. Gallo, 2006: Differences
between near-surface equivalent temperature and temperature
trends for the eastern United States - Equivalent temperature as
an alternative measure of heat content. Global and Planetary
Change, 54, 19-32.
http://climatesci.colorado.edu/publications/pdf/R-268.pdf
Moist enthalpy provides a
proper measure of surface air
heat content, which is not
provided by air temperature
alone.
TE=H/Cp
H = Cp T + L q
Hourly data from automated weather stations at Fort Collins and DIA are used to
pick and calculate the highest air temperature and effective temperature for
each day in July 2005. The average high air temperature is higher at DIA, while
the average high effective temperature is higher at Fort Collins. From Pielke,
R.A. Sr., K. Wolter, O. Bliss, N. Doesken, and B. McNoldy, 2005: July 2005 heat
wave: How unusual was it. National Weather Digest, submitted.
http://climatesci.colorado.edu/publications/pdf/R-313.pdf
http://climatesci.colorado.edu/publications/pdf/R-313.pdf
Davey, C.A., R.A. Pielke Sr., and K.P. Gallo, 2006: Differences between near-surface
equivalent temperature and temperature trends for the eastern United States - Equivalent
temperature as an alternative measure of heat content. Global & Planetary Change, 54, 19-32.
http://climatesci.colorado.edu/publications/pdf/R-268.pdf
Does a temperature sample at a
single level accurately monitor
temperature trends?
¾ Pielke Sr., R.A., and T. Matsui, 2005: Should light wind and windy
nights have the same temperature trends at individual levels even if
the boundary layer averaged heat content change is the same?
Geophys. Res. Letts., 32, No. 21, L21813, 10.1029/2005GL024407
http://climatesci.colorado.edu/publications/pdf/R-302.pdf
¾ Walters, J. T., R. T. McNider, X. Shi, W. B Norris, and J. R. Christy
(2007): Positive surface temperature feedback in the stable nocturnal
boundary layer, Geophys. Res. Lett., 34, L12709,
doi:10.1029/2007GL029505
http://www.agu.org/pubs/crossref/2007/2007GL029505.shtml
¾ Lin, X., R.A. Pielke Sr., K.G. Hubbard, K.C. Crawford, M. A. Shafer, and
T. Matsui, 2007: An examination of 1997-2007 surface layer
temperature trends at two heights in Oklahoma. Geophys. Res. Letts.,
submitted.
http://climatesci.colorado.edu/publications/pdf/R-333.pdf
From: Pielke Sr., R.A., and T. Matsui, 2005: Should light wind and windy
nights have the same temperature trends at individual levels even if the
boundary layer averaged heat content change is the same? Geophys. Res.
Letts., 32, No. 21, L21813, 10.1029/2005GL024407.
http://climatesci.colorado.edu/publications/pdf/R-302.pdf
From: Pielke Sr., R.A., and T. Matsui, 2005: Should light wind and windy
nights have the same temperature trends at individual levels even if the
boundary layer averaged heat content change is the same? Geophys. Res.
Letts., 32, No. 21, L21813, 10.1029/2005GL024407.
http://climatesci.colorado.edu/publications/pdf/R-302.pdf
Does Reanalyses provide more
spatially representative surface
temperature trends?
9 Cai, M, and E. Kalnay, 2005: Can reanalysis have anthropogenic
climate trends without model forcing? J. Climate, 18, 1844-1849.
9 Fall, S., D. Niyogi, R.A. Pielke Sr., A. Gluhovsky, and E. Kalnay,
2007: Impacts of land surface properties on temperature trends
using North American regional reanalysis over the USA. Int. J.
Climatol., submitted.
http://climatesci.colorado.edu/publications/pdf/R-329.pdf
9 Frauenfeld, O.W., T. Zhang, and M.C. Serreze, 2005: Climate
change and variability using European Center for Medium-Range
Weather Forecast analysis (ERA-40) temperatures on the Tibetan
Plateau. J. Geophys. Res., 110, D02101, doi:10.1029/2004JD005230.
9 Kalnay, E., and M. Cai, 2003: Impact of urbanization and land-use
change on climate, Nature, 423, 528- 531.
From: Pielke Sr., R.A. J. Nielsen-Gammon, C. Davey, J. Angel, O. Bliss, N.
Doesken, M. Cai., S. Fall, D. Niyogi, K. Gallo, R. Hale, K.G. Hubbard, X. Lin, H.
Li, and S. Raman, 2007: Documentation of uncertainties and biases associated
with surface temperature measurement sites for climate change assessment.
Bull. Amer. Meteor. Soc., 88:6, 913-928.
http://climatesci.colorado.edu/publications/pdf/R-318.pdf
How many sites are used to monitor
each grid point within the global land
surface analyses from NCDC, CRU,
and GISS?
Do they use the same raw data?
‰ Davey, C.A., and R.A. Pielke Sr., 2007: Comparing station
density and reported temperature trends for land-surface sites.
Climatic Change, in revision
http://climatesci.colorado.edu/publications/pdf/R-319.pdf
Does land-use change and vegetation/soil
dynamics alter the trends in surface temperatures?
[A small sample of papers that address this issue are listed below ]
Carleton, A.M., J. Adegoke, J. Allard, D.L. Arnold, and D.J. Travis, 2001: Summer season land coverconvective cloud associations for the Midwest U.S. "Corn Belt", Geophys. Res. Lett., 28(9), 1679-1682.
Hale, R.C., K.P. Gallo, T.W. Owen, and T.R. Loveland, 2006: Land use/land cover change effects on
temperature trends at U.S. Climate Geophys. Res. Lett.
http://www.agu.org/pubs/crossref/2006/2006GL026358.shtml
Lawrence, P.J., and T.N. Chase, 2007: Representing a new MODIS consistent land surface in the
Community Land Model (CLM 3.0), J. Geophys. Res., 112, G01023, doi:10.1029/2006JG000168.
Lim, Y.-K., M. Cai, E. Kalnay, and L. Zhou, 2005: Observational evidence of sensitivity of surface climate
changes to land types and urbanization. Geophys. Res. Lett., 32,
Niyogi, D., H. Chang, F. Chen, L. Gu, A. Kumar, S. Menon, R. Pielke Sr., 2007: Potential impacts of aerosolland-atmosphere interaction on the Indian monsoonal rainfall characteristics, Nat. Haz.- Monsoon Spe.
Iss,, DOI - 10.1007/s11069-006-9085-y http://climatesci.colorado.edu/publications/pdf/R-303.pdf
Pielke Sr., R.A., J.O. Adegoke, T.N. Chase, C.H. Marshall, T. Matsui, and D. Niyogi, 2007: A new paradigm
for assessing the role of agriculture in the climate system and in climate change. Agric. Forest Meteor.,
Special Issue, 132, 234-254. http://climatesci.colorado.edu/publications/pdf/R-295.pdf
Pielke, R.A. Sr., J. Adegoke, A. Beltran-Przekurat, C.A. Hiemstra, J. Lin, U.S. Nair, D. Niyogi, and T.E.
Nobis, 2007: An overview of regional land use and land cover impacts on rainfall. Tellus B, 59, 587-601.
http://climatesci.colorado.edu/publications/pdf/R-315.pdf
Roy, S.S., R. Mahmood, D. Niyogi, M. Lei, S.A. Foster, K.G. Hubbard, E. Douglas, and R.A. Pielke Sr., 2007:
Impacts of the agricultural green revolution induced land use changes on air temperatures in India. J.
Geophys. Res., accepted. http://climatesci.colorado.edu/publications/pdf/R-323.pdf
Rozoff, C.M., W.R. Cotton, and J.O. Adegoke, 2003: Simulation of St. Louis, Missouri, Land Use Impacts
on Thunderstorms DOI: 10.1175/1520-0450(2003)042<0716:SOSLML>2.0.CO;2
U.S. Geological Survey land-cover classes for pre-1900’s natural conditions (left) and
1993 land-use patterns (right). From Marshall, C.H. Jr., R.A. Pielke Sr., L.T. Steyaert,
and D.A. Willard, 2004: The impact of anthropogenic land-cover change on the Florida
peninsula sea breezes and warm season sensible weather. Mon. Wea. Rev., 132, 28-52.
http://climatesci.colorado.edu/publications/pdf/R-272.pdf
Max and Min
Temp Trends
Two-month
Two-month average
average of
of the
the daily
daily maximum
maximum shelter-level
shelter-level temperature
temperature (°C)
(°C) from
from the
the model
model
simulations
simulations of
of Jul-Aug
Jul-Aug 1989
1989 with
with (top)
(top) natural
natural land
land cover,
cover, (middle)
(middle) current
current land
land cover.
cover.
From
From Marshall
Marshall et
et al.
al. 2004:
2004: The
The impact
impact of
of anthropogenic
anthropogenic land-cover
land-cover change
change on
on the
the
Florida
Florida peninsula
peninsula sea
sea breezes
breezes and
and warm
warm season
season sensible
sensible weather.
weather. Mon.
Mon. Wea.
Wea. Rev.,
Rev., 132,
132,
28-52.
28-52. http://climatesci.colorado.edu/publications/pdf/R-272.pdf
http://climatesci.colorado.edu/publications/pdf/R-272.pdf
Conclusions
¾ Many surface temperature observing sites are poorly located and
cannot be corrected for multi-decadal trends in tenths of a degree C.
¾ Surface temperature only measures part of the heat content of the air;
water vapor content also needs to be measured and its multi-decadal
trend also assessed.
¾ Measuring the temperature at night at one level in the surface
introduces a bias that is on the order of tenths of a degree C.
Conclusions
¾ Regional reanalyses which have dense observed atmospheric input
data provide an effective tool to assess long-term near-surface
temperature trends as well as identify surface observing sites that are
not spatially representative.
¾ Land-use change and/or vegetation-soil dynamics can significantly
alter multi-decadal surface temperature trends.
¾ Many grid points in the NCDC, CRU, and GISS data sets base their
anomalies on none or just 1 site. The degree of correspondence
between the raw data used in the three analyses needs to be
quantified. Also, how many of these sites in urban areas need to be
determined.
¾ The use of ocean heat content changes in Joules is a more robust
method to assess global warming and cooling than the surface
temperature data; an example follows...
Figure 4 from Ellis, J. S., T. H. Vonder Haar, S. Levitus, and A. H. Oort, 1978: The annual
variation in the global heat balance of the Earth. J. Geophys. Res., 83, 1958–1962.
http://climatesci.colorado.edu/publications/pdf/ellis%20et%20al%20JGR%201978.pdf
See also Pielke Sr., R.A., 2003: Heat storage within the Earth system. Bull. Amer. Meteor.
Soc., 84, 331-335. http://climatesci.colorado.edu/publications/pdf/R-247.pdf
From Lyman, J.M., J. Willis, and G. Johnson, 2006: Recent cooling of the upper ocean.
Geophys Res. Lett., 33, L18604, doi:10.1029/2006GL027033. Correction completed April
2007 which eliminates cooling but finds no warming in recent years.
2007 IPCC SPM View
2007 IPCC Total
Radiative Forcing = 1.72
(0.66 to 2.7) Watts per
meter squared
Best Estimate of
Total Radiative
Imbalance (19932005) = 0.33 (0.10
to 0.56) Watts per
meter squared
If the IPCC Forcing
is accepted as the
current forcing,
than the net global
radiative feedbacks
are negative!
Background Photograph Courtesy
of Mike Hollingshead
http://www.extremeinstability.com/index.htm
Roger A. Pielke Sr. Research Group
Weblog
http://climatesci.colorado.edu
Roger A. Pielke Sr. Website
http://cires.colorado.edu/science/groups/pielke
PowerPoint Presentation Prepared by
Dallas Jean Staley
Research Assistant and Webmaster
University of Colorado
Boulder, Colorado 80309
[email protected]