• Bala, G., K. Caldeira, M. Wickett, T. J. Phillips, D. B. Lobell, C. Delire, and A. Mirin, 2007: Combined climate and carbon-cycle effects of large-scale deforestation. Proc. Natl. Acad. Sci. USA, 104, 65506555, doi:10.1073/pnas.0608998104.

    • Search Google Scholar
    • Export Citation
  • Baldocchi, D., and S. Ma, 2013: How will land use affect air temperature in the surface boundary layer? Lessons learned from a comparative study on the energy balance of an oak savanna and annual grassland in California, USA. Tellus, 65B, 19994, doi:10.3402/tellusb.v65i0.19994.

    • Search Google Scholar
    • Export Citation
  • Beltrán-Przekurat, A., R. A. Pielke Sr., J. L. Eastman, and M. B. Coughenour, 2012: Modelling the effects of land-use/land-cover changes on the near-surface atmosphere in southern South America. Int. J. Climatol., 32, 12061225, doi:10.1002/joc.2346.

    • Search Google Scholar
    • Export Citation
  • Blackadar, A. K., 1979: High resolution models of the planetary boundary layer. Adv. Environ. Sci. Eng., 1, 5085.

  • Boisier, J. P., N. de Noblet-Ducoudré, and P. Ciais, 2014: Historical land-use-induced evapotranspiration changes estimated from present-day observations and reconstructed land-cover maps. Hydrol. Earth Syst. Sci., 18, 35713590, doi:10.5194/hess-18-3571-2014.

    • Search Google Scholar
    • Export Citation
  • Bronaugh, W., 2012: North American forests in the Age of Man. American Forests Magazine, Summer 2012, accessed 15 June 2015. [Available online at https://www.americanforests.org/magazine/article/north-american-forests-in-the-age-of-man/.]

  • Cescatti, A., and Coauthors, 2012: Intercomparison of MODIS albedo retrievals and in situ measurements across the global FLUXNET network. Remote Sens. Environ., 121, 323334, doi:10.1016/j.rse.2012.02.019.

    • Search Google Scholar
    • Export Citation
  • Chen, H., H. Tian, M. Liu, J. Melillo, S. Pan, and C. Zhang, 2006: Effect of land-cover change on terrestrial carbon dynamics in the southern United States. J. Environ. Qual., 35, 15331547, doi:10.2134/jeq2005.0198.

    • Search Google Scholar
    • Export Citation
  • Christy, J. R., W. B. Norris, K. Redmond, and K. P. Gallo, 2006: Methodology and results of calculating central California surface temperature trends: Evidence of human-induced climate change? J. Climate, 19, 548563, doi:10.1175/JCLI3627.1.

    • Search Google Scholar
    • Export Citation
  • Crowley, T. J., 2000: Causes of climate change over the past 1000 years. Science, 289, 270277, doi:10.1126/science.289.5477.270.

  • DeGaetano, A. T., and R. J. Allen, 2002: Trends in twentieth-century temperature extremes across the United States. J. Climate, 15, 31883205, doi:10.1175/1520-0442(2002)015<3188:TITCTE>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • de Noblet-Ducoudré, N., and Coauthors, 2012: Determining robust impacts of land-use-induced land cover changes on surface climate over north America and Eurasia: Results from the first set of LUCID experiments. J. Climate, 25, 32613281, doi:10.1175/JCLI-D-11-00338.1.

    • Search Google Scholar
    • Export Citation
  • Dirmeyer, P. A., D. Niyogi, N. de Noblet-Ducoudré, R. E. Dickinson, and P. K. Snyder, 2010: Impacts of land use change on climate. Int. J. Climatol., 30, 19051907, doi:10.1002/joc.2157.

    • Search Google Scholar
    • Export Citation
  • Dobrowski, S. Z., J. Abatzoglou, A. K. Swanson, J. A. Greenberg, A. R. Mynsberge, Z. A. Holden, and M. K. Schwartz, 2013: The climate velocity of the contiguous United States during the 20th century. Global Change Biol., 19, 241251, doi:10.1111/gcb.12026.

    • Search Google Scholar
    • Export Citation
  • Fall, S., D. Niyogi, A. Gluhovsky, R. A. Pielke, E. Kalnay, and G. Rochon, 2010: Impacts of land use land cover on temperature trends over the continental United States: Assessment using the North American Regional Reanalysis. Int. J. Climatol., 30, 19801993, doi:10.1002/joc.1996.

    • Search Google Scholar
    • Export Citation
  • Feddema, J. J., K. W. Oleson, G. B. Bonan, L. O. Mearns, L. E. Buja, G. A. Meehl, and W. M. Washington, 2005: The importance of land-cover change in simulating future climates. Science, 310, 16741678, doi:10.1126/science.1118160.

    • Search Google Scholar
    • Export Citation
  • Findell, K. L., E. Shevliakova, P. C. D. Milly, and R. J. Stouffer, 2007: Modeled impact of anthropogenic land cover change on climate. J. Climate, 20, 36213634, doi:10.1175/JCLI4185.1.

    • Search Google Scholar
    • Export Citation
  • Findell, K. L., A. J. Pitman, M. H. England, and P. J. Pegion, 2009: Regional and global impacts of land cover change and sea surface temperature anomalies. J. Climate, 22, 32483269, doi:10.1175/2008JCLI2580.1.

    • Search Google Scholar
    • Export Citation
  • GCOS, 2004: Summary report of the eighth session of the GCOS/GTOS terrestrial observation panel for climate. GCOS Rep. WMO/TD 1238, 23 pp. [Available online at http://www.wmo.int/pages/prog/gcos/Publications/gcos-93.pdf.]

  • Hansen, M., R. DeFries, J. Townshend, and R. Sohlberg, 2000: Global land cover classification at 1 km spatial resolution using a classification tree approach. Int. J. Remote Sens., 21, 13311364, doi:10.1080/014311600210209.

    • Search Google Scholar
    • Export Citation
  • Hartmann, D. L., and Coauthors, 2013: Observations: Atmosphere and surface. Climate Change 2013: The Physical Science Basis, T. F. Stocker et al., Eds., Cambridge University Press, 159–254.

  • Hoogenboom, G., and Coauthors, 2015: Decision Support System for Agrotechnology Transfer (DSSAT) version 4.6. Accessed July 2014. [Available online at www.dssat.net.]

  • Jackson, R. B., and Coauthors, 2008: Protecting climate with forests. Environ. Res. Lett., 3, 044006, doi:10.1088/1748-9326/3/4/044006.

  • Jacob, D., R. Avissar, G. Bond, and S. Gaffin, 2005: Radiative Forcing of Climate Change: Expanding the Concept and Addressing Uncertainties. National Research Council of the National Academies Press, 224 pp.

  • Jones, J., and Coauthors, 2003: The DSSAT cropping system model. Eur. J. Agron., 18, 235265, doi:10.1016/S1161-0301(02)00107-7.

  • Juang, J.-Y., G. Katul, M. Siqueira, P. Stoy, and K. Novick, 2007: Separating the effects of albedo from eco-physiological changes on surface temperature along a successional chronosequence in the southeastern United States. Geophys. Res. Lett., 34, L21408, doi:10.1029/2007GL031296.

    • Search Google Scholar
    • Export Citation
  • Kalnay, E., and M. Cai, 2003: Impact of urbanization and land-use change on climate. Nature, 423, 528531.

  • Karl, T. R., H. F. Diaz, and G. Kukla, 1988: Urbanization: Its detection and effect in the United States climate record. J. Climate, 1, 10991123, doi:10.1175/1520-0442(1988)001<1099:UIDAEI>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Knappenberger, P. C., P. J. Michaels, and R. E. Davis, 2001: Nature of observed temperature changes across the United States during the 20th century. Climate Res., 17, 4553, doi:10.3354/cr017045.

    • Search Google Scholar
    • Export Citation
  • Kueppers, L. M., M. A. Snyder, and L. C. Sloan, 2007: Irrigation cooling effect: Regional climate forcing by land-use change. Geophys. Res. Lett., 34, L03703, doi:10.1029/2006GL028679.

    • Search Google Scholar
    • Export Citation
  • Kunkel, K. E., X.-Z. Liang, J. Zhu, and Y. Lin, 2006: Can CGCMs simulate the twentieth-century “warming hole” in the central United States? J. Climate, 19, 41374153, doi:10.1175/JCLI3848.1.

    • Search Google Scholar
    • Export Citation
  • Lawrence, P. J., and T. N. Chase, 2010: Investigating the climate impacts of global land cover change in the community climate system model. Int. J. Climatol., 30, 20662087, doi:10.1002/joc.2061.

    • Search Google Scholar
    • Export Citation
  • Lawrence, P. J., and Coauthors, 2012: Simulating the biogeochemical and biogeophysical impacts of transient land cover change and wood harvest in the Community Climate System Model (CCSM4) from 1850 to 2100. J. Climate, 25, 30713095, doi:10.1175/JCLI-D-11-00256.1.

    • Search Google Scholar
    • Export Citation
  • Leibensperger, E. M., and Coauthors, 2012: Climatic effects of 1950–2050 changes in US anthropogenic aerosols—Part 2: Climate response. Atmos. Chem. Phys., 12, 33493362, doi:10.5194/acp-12-3349-2012.

    • Search Google Scholar
    • Export Citation
  • Li, D., and E. Bou-Zeid, 2013: Synergistic interactions between urban heat islands and heat waves: The impact in cities is larger than the sum of its parts. J. Appl. Meteor. Climatol., 52, 20512064, doi:10.1175/JAMC-D-13-02.1.

    • Search Google Scholar
    • Export Citation
  • Mackaro, S. M., R. T. McNider, and A. P. Biazar, 2012: Some physical and computational issues in land surface data assimilation of satellite skin temperatures. Pure Appl. Geophys., 169, 401414, doi:10.1007/s00024-011-0377-0.

    • Search Google Scholar
    • Export Citation
  • Mahmood, R., and Coauthors, 2010: Impacts of land use/land cover change on climate and future research priorities. Bull. Amer. Meteor. Soc., 91, 3746, doi:10.1175/2009BAMS2769.1.

    • Search Google Scholar
    • Export Citation
  • Mahmood, R., and Coauthors, 2014: Land cover changes and their biogeophysical effects on climate. Int. J. Climatol., 34, 929953, doi:10.1002/joc.3736.

    • Search Google Scholar
    • Export Citation
  • McNider, R. T., A. J. Song, D. M. Casey, P. J. Wetzel, W. L. Crosson, and R. M. Rabin, 1994: Toward a dynamic-thermodynamic assimilation of satellite surface temperature in numerical atmospheric models. Mon. Wea. Rev., 122, 27842803, doi:10.1175/1520-0493(1994)122<2784:TADTAO>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • McNider, R. T., W. M. Lapenta, A. P. Biazar, G. J. Jedlovec, R. J. Suggs, and J. Pleim, 2005: Retrieval of model grid-scale heat capacity using geostationary satellite products. Part I: First case-study application. J. Appl. Meteor. Climatol., 44, 13461360, doi:10.1175/JAM2270.1.

    • Search Google Scholar
    • Export Citation
  • McNider, R. T., J. R. Christy, D. Moss, K. Doty, C. Handyside, A. Limaye, A. Garcia y Garcia, and G. Hoogenboom, 2011: A real-time gridded crop model for assessing spatial drought stress on crops in the southeastern United States. J. Appl. Meteor. Climatol., 50, 14591475, doi:10.1175/2011JAMC2476.1.

    • Search Google Scholar
    • Export Citation
  • McNider, R. T., and Coauthors, 2014: An integrated crop and hydrologic modeling system to estimate hydrologic impacts of crop irrigation demands. Environ. Modell. Software, 72, 341355, doi:10.1016/j.envsoft.2014.10.009.

    • Search Google Scholar
    • Export Citation
  • Meehl, G. A., W. M. Washington, C. M. Ammann, J. M. Arblaster, T. M. L. Wigley, and C. Tebaldi, 2004: Combinations of natural and anthropogenic forcings in twentieth-century climate. J. Climate, 17, 37213727, doi:10.1175/1520-0442(2004)017<3721:CONAAF>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Meehl, G. A., and Coauthors, 2012: Climate system response to external forcings and climate change projections in CCSM4. J. Climate, 25, 36613683, doi:10.1175/JCLI-D-11-00240.1.

    • Search Google Scholar
    • Export Citation
  • Meehl, G. A., A. Hu, J. M. Arblaster, J. Fasullo, and K. E. Trenberth, 2013: Externally forced and internally generated decadal climate variability associated with the interdecadal Pacific oscillation. J. Climate, 26, 72987310, doi:10.1175/JCLI-D-12-00548.1.

    • Search Google Scholar
    • Export Citation
  • Misra, V., J.-P. Michael, R. Boyles, E. P. Chassignet, M. Griffin, and J. J. O’Brien, 2012: Reconciling the spatial distribution of the surface temperature trends in the southeastern United States. J. Climate, 25, 36103618, doi:10.1175/JCLI-D-11-00170.1.

    • Search Google Scholar
    • Export Citation
  • Mu, Q., F. A. Heinsch, M. Zhao, and S. W. Running, 2007: Development of a global evapotranspiration algorithm based on MODIS and global meteorology data. Remote Sens. Environ., 111, 519536, doi:10.1016/j.rse.2007.04.015.

    • Search Google Scholar
    • Export Citation
  • Mu, Q., M. Zhao, and S. W. Running, 2011: Improvements to a MODIS global terrestrial evapotranspiration algorithm. Remote Sens. Environ., 115, 17811800, doi:10.1016/j.rse.2011.02.019.

    • Search Google Scholar
    • Export Citation
  • Napton, D. E., R. F. Auch, R. Headley, and J. L. Taylor, 2009: Land changes and their driving forces in the southeastern United States. Reg. Environ. Change, 10, 3753, doi:10.1007/s10113-009-0084-x.

    • Search Google Scholar
    • Export Citation
  • Noilhan, J., and S. Planton, 1989: A simple parameterization of land surface processes for meteorological models. Mon. Wea. Rev., 117, 536549, doi:10.1175/1520-0493(1989)117<0536:ASPOLS>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Oleson, K. W., G. B. Bonan, S. Levis, and M. Vertenstein, 2004: Effects of land use change on North American climate: Impact of surface datasets and model biogeophysics. Climate Dyn., 23, 117132, doi:10.1007/s00382-004-0426-9.

    • Search Google Scholar
    • Export Citation
  • Pan, Z., R. W. Arritt, E. S. Takle, W. J. Gutowski Jr., C. J. Anderson, and M. Segal, 2004: Altered hydrologic feedback in a warming climate introduces a “warming hole.” Geophys. Res. Lett., 31, L17109, doi:10.1029/2004GL020528.

    • Search Google Scholar
    • Export Citation
  • Pielke, R. A., G. Marland, R. A. Betts, T. N. Chase, J. L. Eastman, J. O. Niles, D. D. S. Niyogi, and S. W. Running, 2002: The influence of land-use change and landscape dynamics on the climate system: Relevance to climate-change policy beyond the radiative effect of greenhouse gases. Philos. Trans. Roy. Soc. London, A360, 17051719, doi:10.1098/rsta.2002.1027.

    • Search Google Scholar
    • Export Citation
  • Pielke, R. A., and Coauthors, 2011: Land use/land cover changes and climate: Modeling analysis and observational evidence. Wiley Interdiscip. Rev. Climate Change, 2, 828850, doi:10.1002/wcc.144.

    • Search Google Scholar
    • Export Citation
  • Pitman, A. J., and Coauthors, 2009: Uncertainties in climate responses to past land cover change: First results from the LUCID intercomparison study. Geophys. Res. Lett., 36, L14814, doi:10.1029/2009GL039076.

    • Search Google Scholar
    • Export Citation
  • Pleim, J. E., and A. Xiu, 2003: Development of a land surface model. Part II: Data assimilation. J. Appl. Meteor., 42, 18111822, doi:10.1175/1520-0450(2003)042<1811:DOALSM>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Portmann, R. W., S. Solomon, and G. C. Hegerl, 2009: Spatial and seasonal patterns in climate change, temperatures, and precipitation across the United States. Proc. Natl. Acad. Sci. USA, 106, 73247329, doi:10.1073/pnas.0808533106.

    • Search Google Scholar
    • Export Citation
  • Prestemon, J. P., and R. C. Abt, 2002: Southern forest resource assessment highlights: The southern timber market to 2040. J. For., 100, 1622.

    • Search Google Scholar
    • Export Citation
  • Price, C. V., N. Nakagaki, K. J. Hit, and R. M. Clawges, 2007: Enhanced historical land-use and land-cover data sets of the U.S. Geological Survey. USGS Data Series 240. [Available online at http://pubs.usgs.gov/ds/2006/240/.]

  • Puma, M. J., and B. I. Cook, 2010: Effects of irrigation on global climate during the 20th century. J. Geophys. Res., 115, D16120, doi:10.1029/2010JD014122.

    • Search Google Scholar
    • Export Citation
  • Rahmstorf, S., J. E. Box, G. Feulner, M. E. Mann, A. Robinson, S. Rutherford, and E. J. Schaffernicht, 2015: Exceptional twentieth-century slowdown in Atlantic Ocean overturning circulation. Nat. Climate Change, 5, 475480, doi:10.1038/nclimate2554.

    • Search Google Scholar
    • Export Citation
  • Robinson, W. A., 2002: General circulation model simulations of recent cooling in the east-central United States. J. Geophys. Res., 107, 4748, doi:10.1029/2001JD001577.

    • Search Google Scholar
    • Export Citation
  • Rodionov, S. N., 2004: A sequential algorithm for testing climate regime shifts. Geophys. Res. Lett., 31, L09204, doi:10.1029/2004GL019448.

    • Search Google Scholar
    • Export Citation
  • Rogers, J. C., 2013: The 20th century cooling trend over the southeastern United States. Climate Dyn., 40, 341352, doi:10.1007/s00382-012-1437-6.

    • Search Google Scholar
    • Export Citation
  • Sau, F., K. J. Boote, W. M. Bostick, J. W. Jones, and M. I. Mínguez, 2004: Testing and improving evapotranspiration and soil water balance of the DSSAT crop models. Agron. J., 96, 12431257, doi:10.2134/agronj2004.1243.

    • Search Google Scholar
    • Export Citation
  • Saxena, V. K., and S. Yu, 1998: Searching for a regional fingerprint of aerosol radiative forcing in the southeastern US. Geophys. Res. Lett., 25, 28332836, doi:10.1029/98GL02106.

    • Search Google Scholar
    • Export Citation
  • Shi, W., F. Tao, and J. Liu, 2014: Regional temperature change over the Huang-Huai-Hai Plain of China: The roles of irrigation versus urbanization. Int. J. Climatol., 34, 11811195, doi:10.1002/joc.3755.

    • Search Google Scholar
    • Export Citation
  • Steyaert, L. T., and R. G. Knox, 2008: Reconstructed historical land cover and biophysical parameters for studies of land-atmosphere interactions within the eastern United States. J. Geophys. Res., 113, D02101, doi:10.1029/2006JD008277.

    • Search Google Scholar
    • Export Citation
  • Trail, M., A. P. Tsimpidi, P. Liu, K. Tsigaridis, Y. Hu, A. Nenes, B. Stone, and A. G. Russell, 2013: Potential impact of land use change on future regional climate in the southeastern U.S.: Reforestation and crop land conversion. J. Geophys. Res. Atmos., 118, 11 57711 588, doi:10.1002/2013JD020356.

    • Search Google Scholar
    • Export Citation
  • Vose, R. S., and Coauthors, 2014: Improved historical temperature and precipitation time series for U.S. climate divisions. J. Appl. Meteor. Climatol., 53, 12321251, doi:10.1175/JAMC-D-13-0248.1.

    • Search Google Scholar
    • Export Citation
  • Waisanen, P. J., and N. B. Bliss, 2002: Changes in population and agricultural land in conterminous United States counties, 1790 to 1997. Global Biogeochem. Cycles, 16, 1137, doi:10.1029/2001GB001843.

    • Search Google Scholar
    • Export Citation
  • Wang, H., S. Schubert, M. Suarez, J. Chen, M. Hoerling, A. Kumar, and P. Pegion, 2009: Attribution of the seasonality and regionality in climate trends over the United States during 1950–2000. J. Climate, 22, 25712590, doi:10.1175/2008JCLI2359.1.

    • Search Google Scholar
    • Export Citation
  • Wang, Z., and Coauthors, 2014: Evaluation of MODIS albedo product (MCD43A) over grassland, agriculture and forest surface types during dormant and snow-covered periods. Remote Sens. Environ., 140, 6077, doi:10.1016/j.rse.2013.08.025.

    • Search Google Scholar
    • Export Citation
  • Wetzel, P. J., and J.-T. Chang, 1987: Concerning the relationship between evapotranspiration and soil moisture. J. Climate Appl. Meteor., 26, 1827, doi:10.1175/1520-0450(1987)026<0018:CTRBEA>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Wickham, J. D., T. G. Wade, and K. H. Riitters, 2012: Comparison of cropland and forest surface temperatures across the conterminous United States. Agric. For. Meteor., 166–167, 137143, doi:10.1016/j.agrformet.2012.07.002.

    • Search Google Scholar
    • Export Citation
  • Wickham, J. D., T. G. Wade, and K. H. Riitters, 2014: An isoline separating relatively warm from relatively cool wintertime forest surface temperatures for the southeastern United States. Global Planet. Change, 120, 4653, doi:10.1016/j.gloplacha.2014.05.012.

    • Search Google Scholar
    • Export Citation
  • Wild, M., A. Ohmura, and K. Makowski, 2007: Impact of global dimming and brightening on global warming. Geophys. Res. Lett., 34, L04702, doi:10.1029/2006GL028031.

    • Search Google Scholar
    • Export Citation
  • Yang, Z.-L., Y. Dai, R. E. Dickinson, and W. J. Shuttleworth, 1999: Sensitivity of ground heat flux to vegetation cover fraction and leaf area index. J. Geophys. Res., 104, 19 50519 514, doi:10.1029/1999JD900230.

    • Search Google Scholar
    • Export Citation
  • Yu, S., and Coauthors, 2014: Attribution of the United States “warming hole”: Aerosol indirect effect and precipitable water vapor. Sci. Rep., 4, 6929, doi:10.1038/srep06929.

    • Search Google Scholar
    • Export Citation
  • Zhang, X., L. A. Vincent, W. D. Hogg, and A. Niitsoo, 2000: Temperature and precipitation trends in Canada during the 20th century. Atmos.–Ocean, 38, 395429, doi:10.1080/07055900.2000.9649654.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 509 270 13
PDF Downloads 283 130 9

Towards an Understanding of the Twentieth-Century Cooling Trend in the Southeastern United States: Biogeophysical Impacts of Land-Use Change

View More View Less
  • 1 Earth System Science Center, University of Alabama in Huntsville, Huntsville, Alabama
  • | 2 Department of Atmospheric Science, University of Alabama in Huntsville, Huntsville, Alabama
  • | 3 Earth System Science Center, University of Alabama in Huntsville, Huntsville, Alabama
  • | 4 Earth System Science Center, University of Alabama in Huntsville, Huntsville, Alabama
Restricted access

Abstract

This paper explores the link between the anomalous warming hole in the southeastern United States and a major land-use/land-cover (LULC) change in the region. Land surface and satellite observations were analyzed to estimate the net radiative forcing due to LULC change. Albedo and latent energy were specifically addressed for the dominant LULC change of agriculture to forests. It was assumed that in the energy-limited environment of the region, the partition of changes in available energy due to albedo will mostly impact the sensible heat. The results show that in the southeastern United States, for the period of 1920 to 1992, the changes in sensible (as a result of albedo) and latent energies are in direct competition with each other. In the spring and early summer months, the croplands are in peak production and the latent energy associated with their evapotranspiration (ET) is comparable to that of the forests so the decrease in radiation due to albedo dominates the signal. However, during the late summer and fall months, most major crops have matured, thus reducing their transpiration rate while forests (particularly evergreens) maintain their foliage and with their deep roots are able to continue to transpire as long as atmospheric conditions are favorable. This later influence of latent energy appears to more than offset the increased radiative forcing from the spring and early summer. Overall, a mean annual net radiative forcing resulting from a LULC change from cropland to forests was estimated to be −1.06 W m−2 and thus a probable contribution to the “warming hole” over the Southeast during the majority of the twentieth century.

Corresponding author address: W. L. Ellenburg, Earth System Science Center, University of Alabama in Huntsville, 320 Sparkman Dr., Huntsville, AL 35805. E-mail address: lee.ellenburg@uah.edu

This article is included in the Biogeophysical Climate Impacts of Land Use and Land Cover Change (LULCC) special collection.

Abstract

This paper explores the link between the anomalous warming hole in the southeastern United States and a major land-use/land-cover (LULC) change in the region. Land surface and satellite observations were analyzed to estimate the net radiative forcing due to LULC change. Albedo and latent energy were specifically addressed for the dominant LULC change of agriculture to forests. It was assumed that in the energy-limited environment of the region, the partition of changes in available energy due to albedo will mostly impact the sensible heat. The results show that in the southeastern United States, for the period of 1920 to 1992, the changes in sensible (as a result of albedo) and latent energies are in direct competition with each other. In the spring and early summer months, the croplands are in peak production and the latent energy associated with their evapotranspiration (ET) is comparable to that of the forests so the decrease in radiation due to albedo dominates the signal. However, during the late summer and fall months, most major crops have matured, thus reducing their transpiration rate while forests (particularly evergreens) maintain their foliage and with their deep roots are able to continue to transpire as long as atmospheric conditions are favorable. This later influence of latent energy appears to more than offset the increased radiative forcing from the spring and early summer. Overall, a mean annual net radiative forcing resulting from a LULC change from cropland to forests was estimated to be −1.06 W m−2 and thus a probable contribution to the “warming hole” over the Southeast during the majority of the twentieth century.

Corresponding author address: W. L. Ellenburg, Earth System Science Center, University of Alabama in Huntsville, 320 Sparkman Dr., Huntsville, AL 35805. E-mail address: lee.ellenburg@uah.edu

This article is included in the Biogeophysical Climate Impacts of Land Use and Land Cover Change (LULCC) special collection.

Save