• Arakawa, A., and W. H. Schubert, 1974: Interaction of a cumulus ensemble with the large-scale environment, Part I. J. Atmos. Sci.,31, 674–701.

  • Atlas, R., N. Wolfson, and J. Terry, 1993: The effect of SST and soil moisture anomalies on GLA model simulations of the 1988 U.S. summer drought. J. Climate,6, 2034–2048.

  • Barnett, T. P., and R. Preisendorfer, 1987: Origins and levels of monthly and seasonal forecast skill for United States surface air temperatures determined by canonical correlation analysis. Mon. Wea. Rev.,115, 1825–1850.

  • ——, and Coauthors, 1994: Forecasting global ENSO-related climate anomalies. Tellus,46, 381–397.

  • Barnston, A. G., and R. E. Livezey, 1987: Classification, seasonality and persistence of low-frequency atmospheric circulation patterns. Mon. Wea. Rev.,115, 1083–1126.

  • ——, and Coauthors, 1999: NCEP forecasts of the El Niño of 1997–98 and its U.S. impacts. Bull. Amer. Meteor. Soc.,80, 1829–1852.

  • Bengtsson, L., U. Schlese, E. Roeckner, M. Latif, T. P. Barnett, and N. Graham, 1993: A two-tiered approach to long-range climate forecasting. Science,261, 1026–1029.

  • Blackmon, M. L., and N.-C. Lau, 1980: Regional characteristics of the Northern Hemisphere winter time circulation: A comparison of the simulation of a GFDL general circulation model with observations. J. Atmos. Sci.,37, 497–514.

  • Brankovic, C., T. N. Palmer, and L. Ferranti, 1994: Predictability of seasonal atmospheric variations. J. Climate,7, 217–237.

  • Branstator, G., 1985: Analysis of general circulation model sea surface temperature anomaly simulations using a linear model. Part II: Eigenanalysis. J. Atmos. Sci.,42, 2242–2254.

  • ——, 1992: The maintenance of low-frequency atmospheric anomalies. J. Atmos. Sci.,49, 1924–1945.

  • Chiba, M., K. Yamazaki, K. Shibata, and Y. Kuroda, 1996: The description of the MRI atmospheric spectral GCM (MRI-GSPM) and its mean statistics based on a 10-year integration. Pap. Meteor. Geophys.,47, 1–45.

  • Deser, C., and M. L. Blackmon, 1993: Surface climate variations over the North Atlantic Ocean during winter: 1900–1989. J. Climate,6, 1743–1753.

  • Ferranti, L., F. Molteni, and T. N. Palmer, 1994: Impact of localized tropical and extratropical SST anomalies in ensembles of seasonal GCM integrations. Quart. J. Roy. Meteor. Soc.,120, 1613–1645.

  • Gershunov, A., and T. P. Barnett, 1998: Interdecadal modulation of ENSO teleconnections. Bull. Amer. Meteor. Soc.,79, 2715–2725.

  • Goddard, L., and N. E. Graham, 1999: Importance of the Indian Ocean for simulating rainfall anomalies over eastern and southern Africa. J. Geophys. Res.,104, 19 099–19 116.

  • Graham, N. E., T. P. Barnett, R. Wilde, U. Schlese, and L. Bengtsson, 1994: On the roles of tropical and midlatitude SSTs in forcing interannual to interdecadal variability in the winter Northern Hemisphere circulation. J. Climate,7, 1416–1441.

  • Harshvardhan, R. Davies, D. A. Randall, and T. G. Corsetti, 1987: A fast radiation parameterization for atmospheric circulation models. J. Geophys. Res.,92, 1009–1016.

  • ——, D. A. Randall, T. G. Corsetti, and D. A. Dazlich, 1989: Earth radiation budget and cloudiness simulations with a general circulation model. J. Atmos. Sci.,46, 1922–1942.

  • Held, I. M., S. W. Lyons, and S. Nigam, 1989: Transients and the extratropical response to El Niño. J. Atmos. Sci.,46, 163–174.

  • Hoerling, M. P., and A. Kumar, 1997: Why do North American climate anomalies differ from one El Niño event to another? Geophys. Res. Lett.,24, 1059–1062.

  • ——, and A. Kumar, 2000: Understanding and predicting extratropical teleconnections related to ENSO. El Niño and the Southern Oscillation: Multiscale Variations, Global and Regional Impacts, H. F. Diaz and V. Markgraf, Eds., Cambridge Press, in press.

  • Horel, J. D., and J. M. Wallace, 1981: Planetary-scale atmospheric phenomena associated with the Southern Oscillation. Mon. Wea. Rev.,109, 813–829.

  • ——, and C. R. Mechoso, 1988: Observed and simulated intraseasonal variability of the wintertime planetary circulation. J. Climate,1, 582–599.

  • Hoskins, B., and D. Karoly, 1981: The steady linear response of a spherical atmosphere to thermal and orographic forcing. J. Atmos. Sci.,38, 1179–1196.

  • Ji, M., A. Kumar, and A. Leetmaa, 1994: A multiseason climate forecast system at the National Meteorological Center. Bull. Amer. Meteor. Soc.,75, 569–577.

  • ——, D. W. Behringer, and A. Leetmaa, 1998: An improved coupled model for ENSO prediction and implications for ocean initialization. Part II: The coupled model. Mon. Wea. Rev.,126, 1022–1034.

  • Kalnay, E., and Coauthors, 1996: The NCEP/NCAR 40-Year Reanalysis Project. Bull. Amer. Meteor. Soc.,77, 437–471.

  • Kimoto, M., and M. Ghil, 1993a: Multiple flow regimes in the Northern Hemisphere winter. Part I: Methodology and hemispheric regimes. J. Atmos. Sci.,50, 2625–2643.

  • ——, and ——, 1993b: Multiple flow regimes in the Northern Hemisphere winter. Part II: Sectorial regimes and preferred transitions. J. Atmos. Sci.,50, 2645–2673.

  • Kirchner, I., G. L. Stenchikov, H. F. Graf, A. Robock, and J. C. Antuna, 1998: Climate model simulation of winter warming and summer cooling following the 1991 Mount Pinatubo volcanic eruption. Max-Planck-Institut fur Meteorologie Rep. 261, 35 pp.

  • Klein, S. A., B. J. Soden, and N.-C. Lau, 1999: Remote sea surface temperature variations during ENSO: Evidence for a tropical atmospheric bridge. J. Climate,12, 917–932.

  • Kumar, A., and M. P. Hoerling, 1995: Prospects and limitations of seasonal atmospheric GCM predictions. Bull. Amer. Meteor. Soc.,76, 335–345.

  • ——, and ——, 1997: Interpretation and implications of the observed inter–El Niño variability. J. Climate,10, 83–91.

  • ——, and ——, 1998: Specification of regional sea surface temperatures in atmospheric general circulation model simulations. J. Geophys. Res.,103, 8901–8907.

  • Latif, M., and T. P. Barnett, 1994: Causes of decadal climate variability over the North Pacific and North America. Science,266, 634–637.

  • Lau, N.-C., 1997: Interactions between global SST anomalies and the midlatitude atmospheric circulation. Bull. Amer. Meteor. Soc.,78, 21–33.

  • Legras, B., and M. Ghil, 1985: Persistent anomalies, blocking and variations in atmospheric predictability. J. Atmos. Sci.,42, 433–471.

  • Li, J.-L., and A. Arakawa, 1997: Improved simulation of PBL moist processes with the UCLA GCM. Preprints, Seventh Conf. on Climate Variations, Long Beach, CA, Amer. Meteor. Soc., 35–40.

  • Mechoso, C. R., J.-Y. Yu, and A. Arakawa, 2000: A coupled GCM pilgrimage: From climate catastrophe to ENSO simulations. General Circulation Model Development: Past, Present and Future. Proceedings of a Symposium in Honor of Professor Akio Arakawa, D. A. Randall, Ed., Academic Press, in press.

  • Michelangeli, P.-A., R. Vautard, and B. Legras, 1995: Weather regimes: Recurrence and quasi-stationarity. J. Atmos. Sci.,52, 1137–1256.

  • Murphy, A. H., and E. S. Epstein, 1989: Skill scores and correlation coefficients in model verification. Mon. Wea. Rev.,117, 572–581.

  • Palmer, T. N., 1999: A nonlinear dynamical perspective on climate prediction. J Climate,12, 575–591.

  • ——, and D. L. T. Anderson, 1994: The prospects for seasonal forecasting—A review paper. Quart. J. Roy. Meteor. Soc.,120, 755–793.

  • Pan, D.-M., and D. A. Randall, 1998: A cumulus parameterization with a prognostic closure. Quart. J. Roy. Meteor. Soc.,124, 949–981.

  • Rayner, N. A., C. K. Folland, D. E. Parker, and E. B. Horton, 1995:A new global sea-ice and sea surface temperature (GISST) data set for 1903–1994 for forcing climate models. Wadley Centre Internal Note 69, U.K. Met. Office, 14 pp.

  • Reynolds, R. W., and T. M. Smith, 1995: A high resolution global sea surface temperature climatology. J. Climate,8, 1571–1583.

  • Robertson, A. W., and M. Ghil, 1999: Large-scale weather regimes and local climate over the western United States. J. Climate,12, 1796–1813.

  • ——, C. R. Mechoso, and Y.-J. Kim, 2000: The influence of Atlantic SST anomalies on the North Atlantic oscillation. J. Climate,13, 122–138.

  • Saravanan, R., 1998: Atmospheric low frequency variability and its relationship to midlatitude SST variability: Studies using the NCAR Climate System Model. J. Climate,11, 1386–1404.

  • Sardeshmukh, P. D., and B. J. Hoskins, 1988: The generation of global rotational flow by steady idealized tropical divergence. J. Atmos. Sci.,45, 1228–1251.

  • Schonher, T., and S. E. Nicholson, 1989: The relationship between California rainfall and ENSO events. J. Climate,2, 1258–1269.

  • Silverman, B. W., 1986: Density Estimation for Statistics and Data Analysis. Chapman and Hall, 175 pp.

  • Suarez, M. J., A. Arakawa, and D. A. Randall, 1983: The parameterization of the planetary boundary layer in the UCLA general circulation model: Formulation and results. Mon. Wea. Rev.,111, 2224–2243.

  • Sud, Y. C., G. K. Walker, and W. E. Smith, 1991: Analysis of a general circulation model simulation of the atmospheric response to the observed sea surface temperature anomalies of January and February 1983. J. Climate,4, 107–115.

  • Ting, M., and P. D. Sardeshmukh, 1993: Factors determining the extratropical response to equatorial diabatic heating anomalies. J. Atmos. Sci.,50, 907–918.

  • ——, and L. Yu, 1998: Steady response to tropical heating in wavy linear and nonlinear baroclinic models. J. Atmos. Sci.,55, 3565–3582.

  • Tourre, Y. M., and W. B. White, 1995: ENSO signals in global upper-ocean temperature. J. Phys. Oceanogr.,25, 1317–1332.

  • Wallace, J. M., and D. S. Gutzler, 1981: Teleconnections in the geopotential height field during the Northern Hemisphere winter. Mon. Wea. Rev.,109, 784–811.

  • Xie, 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, 2539–2558.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 44 16 2
PDF Downloads 17 6 0

Ensembles of AGCM Two-Tier Predictions and Simulations of the Circulation Anomalies during Winter 1997–98

John D. FarraraDepartment of Atmospheric Sciences, University of California, Los Angeles, Los Angeles, California

Search for other papers by John D. Farrara in
Current site
Google Scholar
PubMed
Close
,
Carlos R. MechosoDepartment of Atmospheric Sciences, University of California, Los Angeles, Los Angeles, California

Search for other papers by Carlos R. Mechoso in
Current site
Google Scholar
PubMed
Close
, and
Andrew W. RobertsonDepartment of Atmospheric Sciences, University of California, Los Angeles, Los Angeles, California

Search for other papers by Andrew W. Robertson in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

The impact of sea surface temperature (SST) anomalies on the extratropical circulation during the El Niño winter of 1997–98 is studied through atmospheric general circulation model (AGCM) integrations. The model’s midlatitude response is found to be very robust, of the correct amplitude, and to have a fairly realistic spatial structure. The sensitivity of the results to different aspects of the anomalous distributions of SST is analyzed. It is found that the extratropical circulation in the North Pacific–North American sector is significantly different if SST anomalies over the Indian Ocean are included. Using a comparison of observed and simulated 200-hPa streamfunction anomalies, it is argued that the modeled midlatitude impact of Indian Ocean SST anomalies is largely realistic. However, while the local sensitivity of the atmosphere to small differences in SST anomalies in the tropical Pacific can be substantial, the remote sensitivity in midlatitudes is small. Consistently, there is little difference between the simulated extratropical circulation anomalies obtained using SSTs predicted by the National Centers for Environmental Prediction in October 1997 and those obtained using observed tropical Pacific SSTs. Neither is there any detectable atmospheric signal associated with SST anomalies over the North Pacific.

Analyses of the results presented here suggest that the influence of SST anomalies in the Pacific and Indian Oceans during the selected ENSO event can be interpreted as the quasi-linear superposition of Rossby wave trains emanating from the subtropics of each ocean. An inspection of intraseasonal weather regimes suggests that the influence of tropical SST anomalies can also be described as a shift in the frequency of occurrence of the model’s modes of intrinsic variability and a change in their amplitude. These findings suggest the potential utility of SST forecasts for the tropical Indian Ocean.

Corresponding author address: Dr. John D. Farrara, Department of Atmospheric Sciences, University of California, Los Angeles, Los Angeles, CA 90095-1565.

Email: jfarrara@ucla.edu

Abstract

The impact of sea surface temperature (SST) anomalies on the extratropical circulation during the El Niño winter of 1997–98 is studied through atmospheric general circulation model (AGCM) integrations. The model’s midlatitude response is found to be very robust, of the correct amplitude, and to have a fairly realistic spatial structure. The sensitivity of the results to different aspects of the anomalous distributions of SST is analyzed. It is found that the extratropical circulation in the North Pacific–North American sector is significantly different if SST anomalies over the Indian Ocean are included. Using a comparison of observed and simulated 200-hPa streamfunction anomalies, it is argued that the modeled midlatitude impact of Indian Ocean SST anomalies is largely realistic. However, while the local sensitivity of the atmosphere to small differences in SST anomalies in the tropical Pacific can be substantial, the remote sensitivity in midlatitudes is small. Consistently, there is little difference between the simulated extratropical circulation anomalies obtained using SSTs predicted by the National Centers for Environmental Prediction in October 1997 and those obtained using observed tropical Pacific SSTs. Neither is there any detectable atmospheric signal associated with SST anomalies over the North Pacific.

Analyses of the results presented here suggest that the influence of SST anomalies in the Pacific and Indian Oceans during the selected ENSO event can be interpreted as the quasi-linear superposition of Rossby wave trains emanating from the subtropics of each ocean. An inspection of intraseasonal weather regimes suggests that the influence of tropical SST anomalies can also be described as a shift in the frequency of occurrence of the model’s modes of intrinsic variability and a change in their amplitude. These findings suggest the potential utility of SST forecasts for the tropical Indian Ocean.

Corresponding author address: Dr. John D. Farrara, Department of Atmospheric Sciences, University of California, Los Angeles, Los Angeles, CA 90095-1565.

Email: jfarrara@ucla.edu

Save