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General circulation model [GLAS] sensitivity to 1982–1983 equatorial Pacific sea surface temperature anomalies
1002
B. MarineMeteorology
stratification and bottom friction. A general criterion for a barotropic shelf response to wind forcing at periods of a few days due to weather events is derived. Bottom-stress enhancement due to surface gravity waves is found to be important in this problem. Shelf and slope water responses are calculated for the CODE (Coastal Ocean Dynamics Experiment) area. Dept. of Oceanogr. and Geophys. Fluid Dynamics Inst., Florida State Univ., Tallahassee, FL 32306, USA. (wbo) 85:6970 Cubasch, U., 1985. The mean response of the ECMWF global model to the E! Nifio anomaly in extended range prediction experiments. A tmos. Ocean, 23(!):43-66. Numerical experiments were carried out with the low-resolution version of the ECMWF's GCM to ascertain effects of the E1 Nifio SST anomaly. Intensification of the Hadley circulation and the subtropical jet, and a deepening of the Aleutian Low, clearly appear. Teleconnections in mid-latitudes could not be confirmed, however, leaving problematical the utility of such simple models to simulating mid-latitude responses. European Centre for Medium Range Weather Forecasts, Shinfield Park, Reading Berkshire RG2 9AX, UK. (fcs) 85:6971 Fennessy, M.J., L. Marx and J. Shukla, 1985. General circulation model IGLASI sensitivity to 1982-83 equatorial Pacific sea surface temperature anomalies. Mon. Weath. Rev., 113(5):858864. Equatorial Pacific precipitation increased significantly in a wide band stretching from just east of the dateline to the South American coast; west of this region, precipitation was reduced. The major contributor to tropical precipitation changes was the low-level moisture convergence. Largest evaporation differences were around 4 m m / d and occurred over the regions of highest SST. The tropical SLP field showed a marked Southern Oscillation pattern. A strong increase in the equatorial eastern Pacific 850 mb westerlies accompanied a large negative easterly wind anomaly at 200 mb. Tropical precipitation anomalies for 1982-83 were also closely related to the extent of very warm surface waters. Dept. of Meteorol., Univ. of Maryland, College Park, MD 20742, USA. 85:6972 Geisler, J.E., M.L. Blackmon, G.T. Bates and S. Mufloz, 1985. Sen~itivity of January dlmate
OLR (1985)32 (12)
response to the msH~altude and position of equatorial Pacific sea surface temperature anomalies. J. atmos. Sci., 42(10):1037-1049. A change in the amplitude of an SST anomaly of fixed shape and position produces an equatorial Pacific precipitation anomaly just east of the dateline. The most significant midlatitude response is a feature resembling the teleconnection pattern known as the Pacific/North American (PNA) pattern. The midlatitude response is a geographicallyfixed PNA pattern whose amplitude and statistical significance are smaller the farther east the SST anomaly; probability of exciting the PNA pattern decreases as the SST anomaly is moved eastward. Results support the conclusion that the PNA pattern is related to an unstable mode of the atmosphere deriving energy from the zonally asymmetric climatological mean flow. Dept. of Meteorol., Univ. of Utah, Salt Lake City, UT 84112, USA. 85:6973 Joffre, S.M., 1985. Effects of local accelerations and baroclinity on the mean structure of the atmospheric boundary layer over the sea. Bounda~layer Met., 32(3):237-255. Observations over the frozen Baltic Sea are used to consider the influence of the thermal wind effect and inertial terms on mean wind profiles in the atmospheric boundary layer (ABL). Results suggest that the balanced wind at the top of the ABL, rather than the surface geostrophic wind, should be used to parameterize ABL processes. It is also found that local acceleration increases the cross-isobar angle when velocity increases along the mean wind direction, while the geostrophic drag coefficient is minimal for a cross-wind acceleration. Baroclinicity acts to increase the cross-isobar angle under cold air advection, yielding a maximum geostrophic drag when the thermal and surface geostrophic winds are parallel. Finnish Meteorol. Inst., Sahaajank, 22E. 00810 Helsinki, Finland. (fcs) 85:6974 Kershaw, R., 1985. Onset of the south-west monsoon and sea--sorlace temperature anomalies in the Arabian Sea. Nature, Lond., 315(6020):561-563. The onset period of the monsoon, 11-19 June 1979, was selected for international comparison of numerical prediction models. Two examples of numerical predictions highlight the role of SST, namely a control forecast using climatological SST's and an anomaly forecast using more realistic (and warmer) surface temperatures specified for the eastern Arabian Sea. Use of the more accurate SST's enables a better prediction of the development of a monsoon
B. MarineMeteorology
stratification and bottom friction. A general criterion for a barotropic shelf response to wind forcing at periods of a few days due to weather events is derived. Bottom-stress enhancement due to surface gravity waves is found to be important in this problem. Shelf and slope water responses are calculated for the CODE (Coastal Ocean Dynamics Experiment) area. Dept. of Oceanogr. and Geophys. Fluid Dynamics Inst., Florida State Univ., Tallahassee, FL 32306, USA. (wbo) 85:6970 Cubasch, U., 1985. The mean response of the ECMWF global model to the E! Nifio anomaly in extended range prediction experiments. A tmos. Ocean, 23(!):43-66. Numerical experiments were carried out with the low-resolution version of the ECMWF's GCM to ascertain effects of the E1 Nifio SST anomaly. Intensification of the Hadley circulation and the subtropical jet, and a deepening of the Aleutian Low, clearly appear. Teleconnections in mid-latitudes could not be confirmed, however, leaving problematical the utility of such simple models to simulating mid-latitude responses. European Centre for Medium Range Weather Forecasts, Shinfield Park, Reading Berkshire RG2 9AX, UK. (fcs) 85:6971 Fennessy, M.J., L. Marx and J. Shukla, 1985. General circulation model IGLASI sensitivity to 1982-83 equatorial Pacific sea surface temperature anomalies. Mon. Weath. Rev., 113(5):858864. Equatorial Pacific precipitation increased significantly in a wide band stretching from just east of the dateline to the South American coast; west of this region, precipitation was reduced. The major contributor to tropical precipitation changes was the low-level moisture convergence. Largest evaporation differences were around 4 m m / d and occurred over the regions of highest SST. The tropical SLP field showed a marked Southern Oscillation pattern. A strong increase in the equatorial eastern Pacific 850 mb westerlies accompanied a large negative easterly wind anomaly at 200 mb. Tropical precipitation anomalies for 1982-83 were also closely related to the extent of very warm surface waters. Dept. of Meteorol., Univ. of Maryland, College Park, MD 20742, USA. 85:6972 Geisler, J.E., M.L. Blackmon, G.T. Bates and S. Mufloz, 1985. Sen~itivity of January dlmate
OLR (1985)32 (12)
response to the msH~altude and position of equatorial Pacific sea surface temperature anomalies. J. atmos. Sci., 42(10):1037-1049. A change in the amplitude of an SST anomaly of fixed shape and position produces an equatorial Pacific precipitation anomaly just east of the dateline. The most significant midlatitude response is a feature resembling the teleconnection pattern known as the Pacific/North American (PNA) pattern. The midlatitude response is a geographicallyfixed PNA pattern whose amplitude and statistical significance are smaller the farther east the SST anomaly; probability of exciting the PNA pattern decreases as the SST anomaly is moved eastward. Results support the conclusion that the PNA pattern is related to an unstable mode of the atmosphere deriving energy from the zonally asymmetric climatological mean flow. Dept. of Meteorol., Univ. of Utah, Salt Lake City, UT 84112, USA. 85:6973 Joffre, S.M., 1985. Effects of local accelerations and baroclinity on the mean structure of the atmospheric boundary layer over the sea. Bounda~layer Met., 32(3):237-255. Observations over the frozen Baltic Sea are used to consider the influence of the thermal wind effect and inertial terms on mean wind profiles in the atmospheric boundary layer (ABL). Results suggest that the balanced wind at the top of the ABL, rather than the surface geostrophic wind, should be used to parameterize ABL processes. It is also found that local acceleration increases the cross-isobar angle when velocity increases along the mean wind direction, while the geostrophic drag coefficient is minimal for a cross-wind acceleration. Baroclinicity acts to increase the cross-isobar angle under cold air advection, yielding a maximum geostrophic drag when the thermal and surface geostrophic winds are parallel. Finnish Meteorol. Inst., Sahaajank, 22E. 00810 Helsinki, Finland. (fcs) 85:6974 Kershaw, R., 1985. Onset of the south-west monsoon and sea--sorlace temperature anomalies in the Arabian Sea. Nature, Lond., 315(6020):561-563. The onset period of the monsoon, 11-19 June 1979, was selected for international comparison of numerical prediction models. Two examples of numerical predictions highlight the role of SST, namely a control forecast using climatological SST's and an anomaly forecast using more realistic (and warmer) surface temperatures specified for the eastern Arabian Sea. Use of the more accurate SST's enables a better prediction of the development of a monsoon