Search Results - "Shepherd, T. G."

Enhanced seasonal forecast skill following stratospheric sudden warmings by Sigmond, M., Scinocca, J. F., Kharin, V. V., Shepherd, T. G.

“…Advances in seasonal forecasting have brought widespread socio-economic benefits. A modelling study suggests that tropospheric forecast skill is enhanced when…”
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Multimodel Evidence for an Atmospheric Circulation Response to Arctic Sea Ice Loss in the CMIP5 Future Projections by Zappa, G., Pithan, F., Shepherd, T. G.

“…Previous single‐model experiments have found that Arctic sea ice loss can influence the atmospheric circulation. To evaluate this process in a multimodel…”
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Impact of Stratospheric Ozone Recovery on the Southern Hemisphere Westerly Jet by Son, S.-W, Polvani, L.M, Waugh, D.W, Akiyoshi, H, Garcia, R, Kinnison, D, Pawson, S, Rozanov, E, Shepherd, T.G, Shibata, K

“…In the past several decades, the tropospheric westerly winds in the Southern Hemisphere have been observed to accelerate on the poleward side of the surface…”
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Chemistry–Climate Model Simulations of Twenty-First Century Stratospheric Climate and Circulation Changes by Butchart, Neal, Cionni, I., Eyring, V., Shepherd, T. G., Waugh, D. W., Akiyoshi, H., Austin, J., Brühl, C., Chipperfield, M. P., Cordero, E., Dameris, M., Deckert, R., Dhomse, S., Frith, S. M., Garcia, R. R., Gettelman, A., Giorgetta, M. A., Kinnison, D. E., Li, F., Mancini, E., McLandress, C., Pawson, S., Pitari, G., Plummer, D. A., Rozanov, E., Sassi, F., Scinocca, J. F., Shibata, K., Steil, B., Tian, W.

“…The response of stratospheric climate and circulation to increasing amounts of greenhouse gases (GHGs) and ozone recovery in the twenty-first century is…”
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Ozone database in support of CMIP5 simulations: results and corresponding radiative forcing by Cionni, I., Eyring, V., Lamarque, J. F., Randel, W. J., Stevenson, D. S., Wu, F., Bodeker, G. E., Shepherd, T. G., Shindell, D. T., Waugh, D. W.

“…A continuous tropospheric and stratospheric vertically resolved ozone time series, from 1850 to 2099, has been generated to be used as forcing in global…”
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Zonal‐mean circulation response to reduced air–sea momentum roughness by Polichtchouk, I., Shepherd, T. G.

“…The impact of uncertainties in surface‐layer physics on the atmospheric general circulation is comparatively unexplored. Here, the sensitivity of the…”
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Technical Note: A simple procedure for removing temporal discontinuities in ERA-Interim upper stratospheric temperatures for use in nudged chemistry-climate model simulations by McLandress, C, Plummer, D. A, Shepherd, T. G

“…This note describes a simple procedure for removing unphysical temporal discontinuities in ERA-Interim upper stratospheric global mean temperatures in March…”
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Stratospheric variability and tropospheric annular-mode timescales by Simpson, I. R., Hitchcock, P., Shepherd, T. G., Scinocca, J. F.

“…Climate models tend to exhibit much too persistent Southern Annular Mode (SAM) circulation anomalies in summer, compared to observations. Theoretical arguments…”
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A method for merging nadir-sounding climate records, with an application to the global-mean stratospheric temperature data sets from SSU and AMSU by McLandress, C, Shepherd, T. G, Jonsson, A. I, von Clarmann, T, Funke, B

“…A method is proposed for merging different nadir-sounding climate data records using measurements from high-resolution limb sounders to provide a transfer…”
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Multimodel assessment of the upper troposphere and lower stratosphere: Tropics and global trends by Gettelman, A., Hegglin, M. I., Son, S.-W., Kim, J., Fujiwara, M., Birner, T., Kremser, S., Rex, M., Añel, J. A., Akiyoshi, H., Austin, J., Bekki, S., Braesike, P., Brühl, C., Butchart, N., Chipperfield, M., Dameris, M., Dhomse, S., Garny, H., Hardiman, S. C., Jöckel, P., Kinnison, D. E., Lamarque, J. F., Mancini, E., Marchand, M., Michou, M., Morgenstern, O., Pawson, S., Pitari, G., Plummer, D., Pyle, J. A., Rozanov, E., Scinocca, J., Shepherd, T. G., Shibata, K., Smale, D., Teyssèdre, H., Tian, W.

“…The performance of 18 coupled Chemistry Climate Models (CCMs) in the Tropical Tropopause Layer (TTL) is evaluated using qualitative and quantitative…”
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Multi-model assessment of stratospheric ozone return dates and ozone recovery in CCMVal-2 models by Eyring, V., Cionni, I., Bodeker, G. E., Charlton-Perez, A. J., Kinnison, D. E., Scinocca, J. F., Waugh, D. W., Akiyoshi, H., Bekki, S., Chipperfield, M. P., Dameris, M., Dhomse, S., Frith, S. M., Garny, H., Gettelman, A., Kubin, A., Langematz, U., Mancini, E., Marchand, M., Nakamura, T., Oman, L. D., Pawson, S., Pitari, G., Plummer, D. A., Rozanov, E., Shepherd, T. G., Shibata, K., Tian, W., Braesicke, P., Hardiman, S. C., Lamarque, J. F., Morgenstern, O., Pyle, J. A., Smale, D., Yamashita, Y.

“…Projections of stratospheric ozone from a suite of chemistry-climate models (CCMs) have been analyzed. In addition to a reference simulation where…”
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Multimodel projections of stratospheric ozone in the 21st century by Eyring, V., Waugh, D. W., Bodeker, G. E., Cordero, E., Akiyoshi, H., Austin, J., Beagley, S. R., Boville, B. A., Braesicke, P., Brühl, C., Butchart, N., Chipperfield, M. P., Dameris, M., Deckert, R., Deushi, M., Frith, S. M., Garcia, R. R., Gettelman, A., Giorgetta, M. A., Kinnison, D. E., Mancini, E., Manzini, E., Marsh, D. R., Matthes, S., Nagashima, T., Newman, P. A., Nielsen, J. E., Pawson, S., Pitari, G., Plummer, D. A., Rozanov, E., Schraner, M., Scinocca, J. F., Semeniuk, K., Shepherd, T. G., Shibata, K., Steil, B., Stolarski, R. S., Tian, W., Yoshiki, M.

“…Simulations from eleven coupled chemistry‐climate models (CCMs) employing nearly identical forcings have been used to project the evolution of stratospheric…”
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Up-gradient eddy fluxes of potential vorticity near the subtropical jet by Birner, T., J. Thompson, D. W., Shepherd, T. G.

“…The role of eddy fluxes in the general circulation is often approached by treating eddies as (macro)turbulence. In this approach, the eddies act to diffuse…”
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The tropopause inversion layer in models and analyses by Birner, T., Sankey, D., Shepherd, T. G.

“…Recent high‐resolution radiosonde climatologies have revealed a tropopause inversion layer (TIL) in the extratropics: temperature strongly increases just above…”
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Comment on "Tropospheric temperature response to stratospheric ozone recovery in the 21st century" by Hu et al. (2011) by McLandress, C, Perlwitz, J, Shepherd, T. G

“…In a recent paper Hu et al. (2011) suggest that the recovery of stratospheric ozone during the first half of this century will significantly enhance free…”
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The Hiccup: a dynamical coupling process during the autumn transition in the Northern Hemisphere – similarities and differences to sudden stratospheric warmings by Matthias, V., Shepherd, T. G., Hoffmann, P., Rapp, M.

“…Sudden stratospheric warmings (SSWs) are the most prominent vertical coupling process in the middle atmosphere, which occur during winter and are caused by the…”
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On the attribution of stratospheric ozone and temperature changes to changes in ozone-depleting substances and well-mixed greenhouse gases by Shepherd, T. G., Jonsson, A. I.

“…The vertical profile of global-mean stratospheric temperature changes has traditionally represented an important diagnostic for the attribution of the cooling…”
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Response of the Middle Atmosphere to CO₂ Doubling: Results from the Canadian Middle Atmosphere Model by Fomichev, V. I., Jonsson, A. I., De Grandpré, J., Beagley, S. R., Mclandress, C., Semeniuk, K., Shepherd, T. G.

“…The Canadian Middle Atmosphere Model (CMAM) has been used to examine the middle atmosphere response to CO₂ doubling. The radiative-photochemical response…”
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Response of the northern stratospheric polar vortex to the seasonal alignment of QBO phase transitions by Anstey, J. A., Shepherd, T. G.

“…This study considers the strength of the Northern Hemisphere Holton‐Tan effect (HTE) in terms of the phase alignment of the quasi‐biennial oscillation (QBO)…”
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Projections of UV radiation changes in the 21st century: impact of ozone recovery and cloud effects by Bais, A. F., Tourpali, K., Kazantzidis, A., Akiyoshi, H., Bekki, S., Braesicke, P., Chipperfield, M. P., Dameris, M., Eyring, V., Garny, H., Iachetti, D., Jöckel, P., Kubin, A., Langematz, U., Mancini, E., Michou, M., Morgenstern, O., Nakamura, T., Newman, P. A., Pitari, G., Plummer, D. A., Rozanov, E., Shepherd, T. G., Shibata, K., Tian, W., Yamashita, Y.

“…Monthly averaged surface erythemal solar irradiance (UV-Ery) for local noon from 1960 to 2100 has been derived using radiative transfer calculations and…”
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