-
K. Tourpali,
A. F. Bais,
A. Kazantzidis,
C. S. Zerefos,
H. Akiyoshi,
J. Austin,
C. Bruhl,
N. Butchart,
M. P. Chipperfield,
M. Dameris, [......],
M. A. Giorgetta,
D. E. Kinnison,
E. Mancini,
D. R. Marsh, T. Nagashima,
G. Pitari,
D. A. Plummer,
E. Rozanov,
K. Shibata,
W. Tian
[show abstract]
[hide abstract]
ABSTRACT: We have estimated changes in surface solar ultraviolet (UV) radiation under cloud free conditions in the 21st century based on simulations of 11 coupled Chemistry-Climate Models (CCMs). The total ozone columns and vertical profiles of ozone and temperature projected from CCMs were used as input to a radiative transfer model in order to calculate the corresponding erythemal irradiance levels. Time series of monthly erythemal irradiance received at the surface during local noon are presented for the period 1960 to 2100. Starting from the first decade of the 21st century, the surface erythemal irradiance decreases globally as a result of the projected stratospheric ozone recovery at rates that are larger in the first half of the 21st century and smaller towards its end. This decreasing tendency varies with latitude, being more pronounced over areas where stratospheric ozone has been depleted the most after 1980. Between 2000 and 2100 surface erythemal irradiance is projected to decrease over midlatitudes by 5 to 15%, while at the southern high latitudes the decrease is twice as much. In this study we have not included effects from changes in cloudiness, surface reflectivity and tropospheric aerosol loading, which will likely be affected in the future due to climate change. Consequently, over some areas the actual changes in future UV radiation may be different depending on the evolution of these parameters.
Atmospheric Chemistry and Physics. 01/2009; 9(4):1165-1172.
-
K Tourpali,
A F Bais,
A Kazantzidis,
C S Zerefos,
H Akiyoshi,
J Austin,
C B Uhl,
N Butchart,
M P Chipperfield,
M Dameris, [......],
M A Giorgetta,
D E Kinnison,
E Mancini,
D R Marsh, T Nagashima,
G Pitari,
D A Plummer,
E Rozanov,
K Shibata,
W Tian
Atmos. Chem. Phys. Discuss. 01/2008; 8:13043-13062.
-
K. P. Shine,
M. S. Bourqui,
P. M. de F. Forster,
S. H. E. Hare,
U. Langematz,
P. Braesicke,
V. Grewe,
M. Ponater,
C. Schnadt,
C. A. Smith, [......],
D. T. Shindell,
W. J. Randel, T. Nagashima,
R. W. Portmann,
S. Solomon,
D. J. Seidel,
J. Lanzante,
S. Klein,
V. Ramaswamy,
M. D. Schwarzkopf
[show abstract]
[hide abstract]
ABSTRACT: Estimates of annual-mean stratospheric temperature trends over the past twenty years, from a wide variety of models, are compared both with each other and with the observed cooling seen in trend analyses using radiosonde and satellite observations. The modelled temperature trends are driven by changes in ozone (either imposed from observations or calculated by the model), carbon dioxide and other relatively well-mixed greenhouse gases, and stratospheric water vapour.The comparison shows that whilst models generally simulate similar patterns in the vertical profile of annual-and global-mean temperature trends, there is a significant divergence in the size of the modelled trends, even when similar trace gas perturbations are imposed. Coupled-chemistry models are in as good agreement as models using imposed observed ozone trends, despite the extra degree of freedom that the coupled models possess.The modelled annual- and global-mean cooling of the upper stratosphere (near 1 hPa) is dominated by ozone and carbon dioxide changes, and is in reasonable agreement with observations. At about 5 hPa, the mean cooling from the models is systematically greater than that seen in the satellite data; however, for some models, depending on the size of the temperature trend due to stratospheric water vapour changes, the uncertainty estimates of the model and observations just overlap. Near 10 hPa there is good agreement with observations. In the lower stratosphere (20–70 hPa), ozone appears to be the dominant contributor to the observed cooling, although it does not, on its own, seem to explain the entire cooling.Annual- and zonal-mean temperature trends at 100 hPa and 50 hPa are also examined. At 100 hPa, the modelled cooling due to ozone depletion alone is in reasonable agreement with the observed cooling at all latitudes. At 50 hPa, however, the observed cooling at midlatitudes of the northern hemisphere significantly exceeds the modelled cooling due to ozone depletion alone. There is an indication of a similar effect in high northern latitudes, but the greater variability in both models and observations precludes a firm conclusion.The discrepancies between modelled and observed temperature trends in the lower stratosphere are reduced if the cooling effects of increased stratospheric water vapour concentration are included, and could be largely removed if certain assumptions were made regarding the size and distribution of the water vapour increase. However, given the uncertainties in the geographical extent of water vapour changes in the lower stratosphere, and the time period over which such changes have been sustained, other reasons for the discrepancy between modelled and observed temperature trends cannot be ruled out. Copyright © 2003 Royal Meteorological Society
Quarterly Journal of the Royal Meteorological Society 03/2003; 129(590):1565 - 1588. · 2.91 Impact Factor
-
S.B. Andersen,
E.C Weatherhead,
A. Stevermer,
J. Austin,
C. Brühl,
E.L. Fleming,
J. de Grandpré,
Volker Grewe,
I. Isaksen,
G. Pitari,
R.W. Portmann,
B. Rognerud,
J.E. Rosenfield,
S Smyshlyaev, T. Nagashima,
G.J.M. Velders,
D.K. Weisenstein,
J. Xia
[show abstract]
[hide abstract]
ABSTRACT: We present a comparison of trends in total column ozone from 10 two-dimensional and 4 three-dimensional models and solar backscatter ultraviolet–2 (SBUV/2) satellite observations from the period 1979–2003. Trends for the past (1979–2000), the recent 7 years (1996–2003), and the future (2000–2050) are compared. We have analyzed the data using both simple linear trends and linear trends derived with a hockey stick method including a turnaround point in 1996. If the last 7 years, 1996–2003, are analyzed in isolation, the SBUV/2 observations show no increase in ozone, and most of the models predict continued depletion, although at a lesser rate. In sharp contrast to this, the recent data show positive trends for the Northern and the Southern Hemispheres if the hockey stick method with a turnaround point in 1996 is employed for the models and observations. The analysis shows that the observed positive trends in both hemispheres in the recent 7-year period are much larger than what is predicted by the models. The trends derived with the hockey stick method are very dependent on the values just before the turnaround point. The analysis of the recent data therefore depends greatly on these years being representative of the overall trend. Most models underestimate the past trends at middle and high latitudes. This is particularly pronounced in the Northern Hemisphere. Quantitatively, there is much disagreement among the models concerning future trends. However, the models agree that future trends are expected to be positive and less than half the magnitude of the past downward trends. Examination of the model projections shows that there is virtually no correlation between the past and future trends from the individual models.
Journal of Geophysical Research. 111(2006-04):D02303.
-
K. Tourpali,
A.F. Bais,
A. Kazantzidis,
C.S. Zerefos,
H. Akiyoshi,
M. Avngaard,
J. Austin,
C. Brühl,
N. Butchart,
M.P. Chipperfield, [......],
V. Eyring,
Doug Kinnison,
Eva Mancini,
D.R. Marsh, T. Nagashima,
Giovanni Pitari,
D.A. Plummer,
Eugene Rozanov,
K. Shibata,
W. Tian
[show abstract]
[hide abstract]
ABSTRACT: We have estimated changes in surface solar ultraviolet (UV) radiation under cloud free conditions in the 21st century based on simulations of 11 coupled Chemistry- Climate Models (CCMs). The total ozone columns and vertical profiles of ozone and temperature projected from CCMs were used as input to a radiative transfer model in order to calculate the corresponding erythemal irradiance levels. Time series of monthly erythemal irradiance received at the surface during local noon are presented for the period 1960 to 2100. Starting from the first decade of the 21st century, the surface erythemal irradiance decreases globally as a result of the projected stratospheric ozone recovery at rates that are larger in the first half of the 21st century and smaller towards its end. This decreasing tendency varies with latitude, being more pronounced over areas where stratospheric ozone has been depleted the most after 1980. Between 2000 and 2100 surface erythemal irradiance is projected to decrease
over midlatitudes by 5 to 15%, while at the southern high latitudes the decrease is twice as much. In this study we have not included effects from changes in cloudiness, surface reflectivity and tropospheric aerosol loading, which will likely be affected in the future due to climate change. Consequently,
over some areas the actual changes in future UV radiation may be different depending on the evolution of these parameters.
Atmospheric Chemistry and Physics. 9(2009-02):1165-1172.
-
J. Austin,
K. Tourpali,
E. Rozanov,
H Akiyoshi,
S. Bekki,
G. Bodeker,
C. Brühl,
N. Butchart,
M. Chipperfield,
M. Deushi, [......],
K. Kodera,
F. Lott,
E. Manzini,
D. Marsh,
K. Matthes, T Nagashima,
K Shibata,
R. S. Stolarski,
H. Struthers,
W Tian
Journal of Geophysical Research-Atmospheres, v.113 (2008).
-
V. Eyring,
J. Austin,
D. Shindell,
S.R. Beagley,
C. Brühl,
M. Dameris,
E. Manzini, T. Nagashima,
P. Newman,
S. Pawson,
G. Pitari,
E. Rozanov,
C. Schnadt,
T.G. Shepherd
Workshop on Arctic Ozone Loss;
-
K. Tourpali,
A. F. Bais,
A. Kazantzidis,
C. S. Zerefos,
H Akiyoshi,
J. Austin,
C. Brühl,
N. Butchart,
M. P. Chipperfield,
M. Dameris, [......],
M. A. Giorgetta,
D. E. Kinnison,
E. Mancini,
D. R. Marsh, T Nagashima,
G. Pitari,
D. A. Plummer,
E. Rozanov,
K Shibata,
W Tian
Atmospheric Chemistry and Physics, v.9, 1165-1172 (2009).
-
V. Eyring,
N.R.P. Harris,
M. Rex,
T.G. Shepherd,
D.W. Fahey,
G. Amanatidis,
J. Austin,
M. Dameris,
H. Graf, T. Nagashima,
P.A. Newman,
B.D. Santer
Quadrennial Ozone Symposium 2004;
-
J. Austin,
D. Shindell,
S.R. Beagley,
C. Brühl,
M. Dameris,
E. Manzini, T. Nagashima,
P. Newman,
S. Pawson,
G. Pitari,
E. Rozanov,
C. Schnadt,
T.G. Shepherd
Atmospheric Chemistry and Physics. 3(2003):1-27.
-
SPARC Newsletter. 22(2004):27-28.
-
K. Tourpali,
A. F. Bais,
A. Kazantzidis,
C. S. Zerefos,
H Akiyoshi,
J. Austin,
C. Brühl,
N. Butchart,
M. P. Chipperfield,
M. Dameris, [......],
M. A. Giorgetta,
D. E. Kinnison,
E. Mancini,
D. R. Marsh, T Nagashima,
G. Pitari,
D. A. Plummer,
E. Rozanov,
K Shibata,
W Tian
Atmospheric Chemistry and Physics Discussions, v.8, 13043-13062 (2008).
-
S. B. Andersen,
E. C. Weatherhead,
A. Stevermer,
J. Austin,
C. Brühl,
E. L. Fleming,
J. de Grandpré,
V. Grewe,
I. Isaksen,
G. Pitari,
R. W. Portmann,
B. Rognerud,
J. E. Rosenfield,
S. Smyshlyaev, T Nagashima,
G. J. M. Velders,
D. K. Weisenstein,
J. Xia
Journal of Geophysical Research-Atmospheres, v.111 (2006).
-
V. Eyring,
N. Butchart,
D. W. Waugh,
H Akiyoshi,
J. Austin,
S. Bekki,
G. E. Bodeker,
B. A. Boville,
C. Brühl,
M. P. Chipperfield, [......],
G. Pitari,
D. A. Plummer,
E. Rozanov,
M. Schraner,
T. G. Shepherd,
K Shibata,
R. S. Stolarski,
H. Struthers,
W Tian,
M. Yoshiki
Journal of Geophysical Research-Atmospheres, v.111 (2006).
-
V. Eyring,
D.W. Waugh,
G.E. Bodeker,
E. Cordero,
H. Akiyoshi,
J. Austin,
S.R. Beagley,
B. Boville,
P. Braesicke,
C. Brühl, [......],
E. Rozanov,
M. Schraner,
J.F. Scinocca,
K. Semeniuk,
T.G. Shepherd,
K. Shibata,
B. Steil,
R. Stolarski,
W. Tian,
M. Yoshiki
[show abstract]
[hide abstract]
ABSTRACT: Simulations from eleven coupled chemistry-climate models (CCMs) employing
nearly identical forcings have been used to project the evolution of stratospheric ozone
throughout the 21st century. The model-to-model agreement in projected temperature
trends is good, and all CCMs predict continued, global mean cooling of the stratosphere
over the next 5 decades, increasing from around 0.25 K/decade at 50 hPa to around 1 K/
decade at 1 hPa under the Intergovernmental Panel on Climate Change (IPCC) Special
Report on Emissions Scenarios (SRES) A1B scenario. In general, the simulated ozone
evolution is mainly determined by decreases in halogen concentrations and continued
cooling of the global stratosphere due to increases in greenhouse gases (GHGs). Column
ozone is projected to increase as stratospheric halogen concentrations return to 1980s
levels. Because of ozone increases in the middle and upper stratosphere due to GHGinduced
cooling, total ozone averaged over midlatitudes, outside the polar regions, and
globally, is projected to increase to 1980 values between 2035 and 2050 and before lowerstratospheric
halogen amounts decrease to 1980 values. In the polar regions the CCMs
simulate small temperature trends in the first and second half of the 21st century in midwinter. Differences in stratospheric inorganic chlorine (Cly) among the CCMs are key to diagnosing the intermodel differences in simulated ozone recovery, in particular in the Antarctic. It is found that there are substantial quantitative differences in the simulated Cly, with the October mean Antarctic Cly peak value varying from less than 2 ppb to over 3.5 ppb in the CCMs, and the date at which the Cly returns to 1980 values varying from before 2030 to after 2050. There is a similar variation in the timing of recovery of Antarctic
springtime column ozone back to 1980 values. As most models underestimate peak Cly near 2000, ozone recovery in the Antarctic could occur even later, between 2060 and 2070. In the Arctic the column ozone increase in spring does not follow halogen decreases as closely as in the Antarctic, reaching 1980 values before Arctic halogen amounts decrease
Journal of Geophysical Research. 112(2007-D16303):1-24.
-
J Austin,
R J Wilson,
H Akiyoshi,
S Bekki,
N Butchart,
C Claud,
V I Fomichev,
P Forster,
R R Garcia,
N P Gillett, [......],
E Manzini, T Nagashima,
W J Randel,
E Rozanov,
K Shibata,
K P Shine,
H Struthers,
D W J Thompson,
F Wu,
S Yoden
[show abstract]
[hide abstract]
ABSTRACT: 1] Temperature results from multi-decadal simulations of coupled chemistry climate models for the recent past are analyzed using multi-linear regression including a trend, solar cycle, lower stratospheric tropical wind, and volcanic aerosol terms. The climatology of the models for recent years is in good agreement with observations for the troposphere but the model results diverge from each other and from observations in the stratosphere. Overall, the models agree better with observations than in previous assessments, primarily because of corrections in the observed temperatures. The annually averaged global and polar temperature trends simulated by the models are generally in agreement with revised satellite observations and radiosonde data over much of their altitude range. In the global average, the model trends underpredict the radiosonde data slightly at the top of the observed range. Over the Antarctic some models underpredict the temperature trend in the lower stratosphere, while others overpredict the trends. Citation: Austin, J., et al. (2009), Coupled chemistry climate model simulations of stratospheric temperatures and their trends for the recent past, Geophys. Res. Lett., 36, L13809, doi:10.1029/2009GL038462.
-
V. Eyring,
D. W. Waugh,
G. E. Bodeker,
E. Cordero,
H Akiyoshi,
J. Austin,
S. R. Beagley,
B. A. Boville,
P. Braesicke,
C. Brühl, [......],
E. Rozanov,
M. Schraner,
J. F. Scinocca,
K. Semeniuk,
T. G. Shepherd,
K Shibata,
B. Steil,
R. S. Stolarski,
W Tian,
M. Yoshiki
Journal of Geophysical Research-Atmospheres, v.112 (2007).
-
J. Austin,
K. Tourpali,
E. Rozanov,
H Akiyoshi,
S. Bekki,
G. Bodeker,
C. Bruhl,
N. Butchart,
N. Chipperfield,
M. Deushi, [......],
K. Kodera,
F. Lott,
E. Manzini,
D. Marshall,
L. Matthes, T Nagashima,
K Shibata,
R. S. Stolarski,
H. Struthers,
W Tian
[show abstract]
[hide abstract]
ABSTRACT: Austin, J., Tourpali, K., Rozanov, E., Akiyoshi, H., Bekki, S., Bodeker, G., Bruhl, C., Butchart, N., Chipperfield, M., Deushi, M., Fomichev, V.I., Giorgetta, M.A., Gray, L., Kodera, K., Lott, F., Manzini, E., Marsh, D., Matthes, K., Nagashima, T., Shibata, K., Stolarski, R.S., Struthers, H. and Tian, W. Coupled chemistry climate model simulations of the solar cycle in ozone and temperature Journal of Geophysical Research-Atmospheres, 113, 2008,
-
S. B. Andersen,
E. C. Weatherhead,
J. Austin,
Ch. Brühl,
E.L. Fleming,
Grandpre J. de,
V. Grewe,
I.S.A. Isaksen,
G. Pitari,
W. Portmann,
B. Rognerud,
J. E. Rosenfield,
D. Shindell,
S. Smyshlayev, T. Nagashima,
G.J.M. Velders,
D. K. Weisenstein,
J. Xia
Quadrennial Ozone Symposium 2004;
-
V. Eyring,
N.R.P. Harris,
M. Rex,
T.G. Shepherd,
D.W. Fahey,
G.T. Amanatidis,
J. Austin,
M.P. Chipperfield,
M. Dameris,
P.M. de F. Forster,
A. Gettelman,
H.F. Graf, T. Nagashima,
P.A. Newman,
S. Pawson,
M.J. Prather,
J. A. Pyle,
R.J. Salawitch,
B.D. Santer,
D.W. Waugh
Bulletin of the American Meteorological Society.
