• Barnston, A., S. Li, S. Mason, D. DeWitt, L. Goddard, and X. Gong, 2010: Verification of the first 11 years of IRI’s seasonal climate forecasts. J. Appl. Meteor. Climatol., 49, 493520.

    • Search Google Scholar
    • Export Citation
  • Boer, G. J., 1993: Climate change and the regulation of the surface moisture and energy budgets. Climate Dyn., 8, 225239.

  • Chahine, M. T., 1992: The hydrological cycle and its influence on climate. Nature, 359, 373380.

  • Held, I. M., S. W. Lyons, and S. Nigam, 1989: Transients and the extratropical response to El Niño. J. Atmos. Sci., 46, 163174.

  • Hoerling, M. P., and M. Ting, 1994: On the organization of extratropical transients during El Niño. J. Climate, 7, 745766.

  • Hoerling, M. P., and A. Kumar, 2000: Understanding and predicting extratropical teleconnections related to ENSO. El Niño and the Southern Oscillation: Multi-Scale Variability, and Global and Regional Impacts, H. Diaz and V. Markgraf, Eds., Cambridge University Press, 57–88.

    • Search Google Scholar
    • Export Citation
  • Hoerling, M. P., A. Kumar, and M. Zhong, 1997: El Niño, La Niña, and the nonlinearity of their teleconnections. J. Climate, 10, 17691786.

    • Search Google Scholar
    • Export Citation
  • Kalnay, E., and Coauthors, 1996: The NCEP/NCAR 40-Year Reanalysis Project. Bull. Amer. Meteor. Soc., 77, 437471.

  • Kiladis, G. N., and H. Diaz, 1989: Global climatic anomalies associated with extremes in the Southern Oscillation. J. Climate, 2, 10691090.

    • Search Google Scholar
    • Export Citation
  • Kumar, A., M. Hoerling, M. Ji, A. Leetmaa, and P. Sardeshmukh, 1996: Assessing a GCM’s suitability for making seasonal predictions. J. Climate, 9, 115129.

    • Search Google Scholar
    • Export Citation
  • Larkin, N. K., and D. E. Harrison, 2005: On the definition of El Niño and associated seasonal average U.S. weather anomalies. Geophys. Res. Lett., 32, L13705, doi:10.1029/2005GL022738.

    • Search Google Scholar
    • Export Citation
  • Lau, N. C., A. Leetmaa, and M. J. Nath, 2008: Interactions between the responses of North American climate to El Niño–La Niña and to the secular warming trend in the Indian–western Pacific Oceans. J. Climate, 21, 476494.

    • Search Google Scholar
    • Export Citation
  • May, W., and L. Bengtsson, 1998: The signature of ENSO in the Northern Hemisphere midlatitude seasonal mean flow and high-frequency intraseasonal variability. Meteor. Atmos. Phys., 69, 81100.

    • Search Google Scholar
    • Export Citation
  • Mesinger, F., and Coauthors, 2006: North American Regional Reanalysis. Bull. Amer. Meteor. Soc., 87, 343360.

  • Notaro, M., Z. Liu, and J. W. Williams, 2006: Observed vegetation–climate feedbacks in the United States. J. Climate, 19, 763786.

  • Quan, X., M. P. Hoerling, J. Whitaker, G. Bates, and T. Xu, 2006: Diagnosing sources of U.S. seasonal forecast skill. J. Climate, 19, 32793293.

    • Search Google Scholar
    • Export Citation
  • Ramanathan, V., P. J. Crutzen, J. T. Kiehl, and D. Rosenfeld, 2001: Aerosol, climate and the hydrological cycle. Science, 294, 21192124.

    • Search Google Scholar
    • Export Citation
  • Ropelewski, C. F., and M. S. Halpert, 1986: North American precipitation and temperature patterns associated with the El Niño–Southern Oscillation (ENSO). Mon. Wea. Rev., 114, 23522362.

    • Search Google Scholar
    • Export Citation
  • Ropelewski, C. F., and M. S. Halpert, 1987: Global and regional scale precipitation patterns associated with the El Niño–Southern Oscillation. Mon. Wea. Rev., 115, 16061626.

    • Search Google Scholar
    • Export Citation
  • Rossow, W. B., A. W. Walker, D. E. Beuschel, and M. D. Roiter, 1996: International Satellite Cloud Climatology Project (ISCCP) documentation of new cloud datasets. World Meteorological Organization Rep. WMO/TD-737, 115 pp.

    • Search Google Scholar
    • Export Citation
  • Soden, B. J., 2000: The sensitivity of the tropical hydrological cycle to ENSO. J. Climate, 13, 538549.

  • Sun, D.-Z., J. Fasullo, T. Zhang, and A. Roubicek, 2003: On the radiative and dynamical feedbacks over the equatorial Pacific cold tongue. J. Climate, 16, 24252432.

    • Search Google Scholar
    • Export Citation
  • Sun, D.-Z., and Coauthors, 2006: Radiative and dynamical feedbacks over the equatorial cold-tongue: Results from nine atmospheric GCMs. J. Climate, 19, 40594074.

    • Search Google Scholar
    • Export Citation
  • Sun, D.-Z., Y. Yu, and T. Zhang, 2009: Tropical water vapor and cloud feedbacks in climate models: A further assessment using coupled simulations. J. Climate, 22, 12871304.

    • Search Google Scholar
    • Export Citation
  • Trenberth, K. E., 1997: Using atmospheric budgets as a constraint on surface fluxes. J. Climate, 10, 27962809.

  • Trenberth, K. E., G. W. Branstator, D. Karoly, A. Kumar, N.-C. Lau, and C. Ropelewski, 1998: Progress during TOGA in understanding and modeling global teleconnections associated with tropical sea surface temperatures. J. Geophys. Res., 103, 14 29114 324.

    • Search Google Scholar
    • Export Citation
  • Tucker, C. J., J. E. Pinzon, M. E. Brown, D. A. Slayback, E. W. Pak, R. Mahoney, E. F. Vermote, and N. El Saleous, 2005: An extended AVHRR 8-km NDVI dataset compatible with MODIS and SPOT vegetation NDVI data. Int. J. Remote Sens., 26, 44854498.

    • Search Google Scholar
    • Export Citation
  • Twomey, S. A., C. F. Bohren, and J. L. Mergenthaler, 1986: Reflectances and albedo differences between wet and dry surfaces. Appl. Opt., 25, 431437.

    • Search Google Scholar
    • Export Citation
  • Uppala, S. M., and Coauthors, 2005: The ERA-40 Re-Analysis. Quart. J. Roy. Meteor. Soc., 131, 29613012, doi:10.1256/qj.04.176.

  • Wang, Z., C. P. Chang, and B. Wang, 2007: Impacts of El Niño and La Niña on the U.S. climate during northern summer. J. Climate, 20, 21652177.

    • Search Google Scholar
    • Export Citation
  • Wild, M., A. Ohmura, H. Gilgen, and D. Rosenfeld, 2004: On the consistency of trends in radiation and temperature records and implications for the global hydrological cycle. Geophys. Res. Lett., 31, L11201, doi:10.1029/2003GL019188.

    • Search Google Scholar
    • Export Citation
  • Xie, P. P., and P. A. Arkin, 1997: Global precipitation: A 17-year monthly analysis based on gauge observations, satellite estimates, and numerical model outputs. Bull. Amer. Meteor. Soc., 78, 25392558.

    • Search Google Scholar
    • Export Citation
  • Yang, F., A. Kumar, W. Wang, H.-M. H. Juang, and M. Kanamitsu, 2001: Snow–albedo feedback and seasonal climate variability over North America. J. Climate, 14, 42454248.

    • Search Google Scholar
    • Export Citation
  • Zhang, T., and D.-Z. Sun, 2006: Response of water vapor and clouds to El Niño warming in three National Center for Atmospheric Research atmospheric models. J. Geophys. Res., 111, D17103, doi:10.1029/2005JD006700.

    • Search Google Scholar
    • Export Citation
  • Zhang, T., and D.-Z. Sun, 2008: What causes the excessive response of clear-sky greenhouse effect to El Niño warming in Community Atmosphere Models? J. Geophys. Res., 113, D02108, doi:10.1029/2007JD009247.

    • Search Google Scholar
    • Export Citation
  • Zhang, Y., W. B. Rossow, A. A. Lacis, V. Oinas, and M. I. Mishchenko, 2004: Calculation of radiative fluxes from the surface to top of atmosphere based on ISCCP and other global data sets: Refinements of the radiative transfer model and the input data. J. Geophys. Res., 109, D19105, doi:10.1029/2003JD004457.

    • Search Google Scholar
    • Export Citation
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Physics of U.S. Surface Temperature Response to ENSO

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  • 1 Cooperative Institute for Research in Environmental Sciences, University of Colorado, and Physical Sciences Division, NOAA/Earth System Research Laboratory, Boulder, Colorado
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Abstract

To elucidate physical processes responsible for the response of U.S. surface temperatures to El Niño–Southern Oscillation (ENSO), the surface energy balance is diagnosed from observations, with emphasis on the role of clouds, water vapor, and land surface properties associated with snow cover and soil moisture. Results for the winter season (December–February) indicate that U.S. surface temperature conditions associated with ENSO are determined principally by anomalies in the surface radiative heating—the sum of absorbed solar radiation and downward longwave radiation. Each component of the surface radiative heating is linked with specific characteristics of the atmospheric hydrologic response to ENSO and also to feedbacks by the land surface response. During El Niño, surface warming over the northern United States is physically consistent with three primary processes: 1) increased downward solar radiation due to reduced cloud optical thickness, 2) reduced reflected solar radiation due to an albedo decline resulting from snow cover loss, and 3) increased downward longwave radiation linked to an increase in precipitable water. In contrast, surface cooling over the southern United States during El Niño is mainly the result of a reduction in incoming solar radiation resulting from increased cloud optical thickness. During La Niña, surface warming over the central United States results mainly from snow cover losses, whereas warming over the southern United States results mainly from a reduction in cloud optical thickness that yields increased incoming solar radiation and also from an increase in precipitable water that enhances the downward longwave radiation. For both phases of ENSO the surface radiation budget is closely linked to large-scale horizontal and vertical motions in the free atmosphere through two main processes: 1) the convergence of the atmospheric water vapor transport that largely determines cloud optical thickness and thereby affects incoming shortwave radiation and 2) the changes in tropospheric column temperature resulting from the characteristic atmospheric teleconnections that largely determine column precipitable water and thereby affect downward longwave radiation.

Corresponding author address: Dr. Tao Zhang, NOAA/ESRL/PSD, R/PSD1, 325 Broadway, Boulder, CO 80305. E-mail: tao.zhang@noaa.gov

Abstract

To elucidate physical processes responsible for the response of U.S. surface temperatures to El Niño–Southern Oscillation (ENSO), the surface energy balance is diagnosed from observations, with emphasis on the role of clouds, water vapor, and land surface properties associated with snow cover and soil moisture. Results for the winter season (December–February) indicate that U.S. surface temperature conditions associated with ENSO are determined principally by anomalies in the surface radiative heating—the sum of absorbed solar radiation and downward longwave radiation. Each component of the surface radiative heating is linked with specific characteristics of the atmospheric hydrologic response to ENSO and also to feedbacks by the land surface response. During El Niño, surface warming over the northern United States is physically consistent with three primary processes: 1) increased downward solar radiation due to reduced cloud optical thickness, 2) reduced reflected solar radiation due to an albedo decline resulting from snow cover loss, and 3) increased downward longwave radiation linked to an increase in precipitable water. In contrast, surface cooling over the southern United States during El Niño is mainly the result of a reduction in incoming solar radiation resulting from increased cloud optical thickness. During La Niña, surface warming over the central United States results mainly from snow cover losses, whereas warming over the southern United States results mainly from a reduction in cloud optical thickness that yields increased incoming solar radiation and also from an increase in precipitable water that enhances the downward longwave radiation. For both phases of ENSO the surface radiation budget is closely linked to large-scale horizontal and vertical motions in the free atmosphere through two main processes: 1) the convergence of the atmospheric water vapor transport that largely determines cloud optical thickness and thereby affects incoming shortwave radiation and 2) the changes in tropospheric column temperature resulting from the characteristic atmospheric teleconnections that largely determine column precipitable water and thereby affect downward longwave radiation.

Corresponding author address: Dr. Tao Zhang, NOAA/ESRL/PSD, R/PSD1, 325 Broadway, Boulder, CO 80305. E-mail: tao.zhang@noaa.gov
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