-
B. Funke,
A. Baumgaertner,
M. Calisto,
T. Egorova,
C. H. Jackman,
J. Kieser,
A. Krivolutsky,
M. López-Puertas, D. R. Marsh,
T. Reddmann,
E. Rozanov,
S.-M. Salmi,
M. Sinnhuber,
G. P. Stiller,
P. T. Verronen,
S. Versick,
T. von Clarmann,
T. Y. Vyushkova,
N. Wieters,
J. M. Wissing
[show abstract]
[hide abstract]
ABSTRACT: We have compared composition changes of NO, NO2,
H2O2, O3, N2O,
HNO3, N2O5, HNO4, ClO, HOCl,
and ClONO2 as observed by the Michelson Interferometer for
Passive Atmospheric Sounding (MIPAS) on Envisat in the aftermath of the
"Halloween" solar proton event (SPE) in October/November 2003 at 25-0.01
hPa in the Northern Hemisphere (40-90° N) and simulations performed
by the following atmospheric models: the Bremen 2d Model (B2dM) and
Bremen 3d Chemical Transport Model (B3dCTM), the Central Aerological
Observatory (CAO) model, FinROSE, the Hamburg Model of the Neutral and
Ionized Atmosphere (HAMMONIA), the Karlsruhe Simulation Model of the
Middle Atmosphere (KASIMA), the ECHAM5/MESSy Atmospheric Chemistry
(EMAC) model, the modeling tool for SOlar Climate Ozone Links studies
(SOCOL and SOCOLi), and the Whole Atmosphere Community Climate Model
(WACCM4). The large number of participating models allowed for an
evaluation of the overall ability of atmospheric models to reproduce
observed atmospheric perturbations generated by SPEs, particularly with
respect to NOy and ozone changes. We have further assessed
the meteorological conditions and their implications on the chemical
response to the SPE in both the models and observations by comparing
temperature and tracer (CH4 and CO) fields.
Simulated SPE-induced ozone losses agree on average within 5% with the
observations. Simulated noy enhancements around 1 hPa, however, are
typically 30% higher than indicated by the observations which can be
partly attributed to an overestimation of simulated electron-induced
ionization. The analysis of the observed and modeled NOy
partitioning in the aftermath of the SPE has demonstrated the need to
implement additional ion chemistry (HNO3 formation via
ion-ion recombination and water cluster ions) into the chemical schemes.
An overestimation of observed H2O enhancements by all models
hints at an underestimation of the OH/HO2 ratio in the upper
polar stratosphere during the SPE. The analysis of chlorine species
perturbations has shown that the encountered differences between models
and observations, particularly the underestimation of observed
ClONO2 enhancements, are related to a smaller availability of
ClO in the polar night region already before the SPE. In general, the
intercomparison has demonstrated that differences in the meteorology
and/or initial state of the atmosphere in the simulations causes a
relevant variability of the model results, even on a short timescale of
only a few days.
Atmospheric Chemistry and Physics 02/2011; 11:9407-9514. · 4.88 Impact Factor
-
B. Funke,
A. Baumgaertner,
M. Calisto,
T. Egorova,
C. H. Jackman,
J. Kieser,
A. Krivolutsky,
M. López-Puertas, D. R. Marsh,
T. Reddmann,
E. Rozanov,
S. -M. Salmi,
M. Sinnhuber,
G. P. Stiller,
P. T. Verronen,
S. Versick,
T. Clarmann von,
T. Y. Vyushkova,
N. Wieters,
J. M. Wissing
Atmos. Chem. Phys. 01/2011; 11(17):9089-9139.
-
C. H. Jackman, D. R. Marsh,
F. M. Vitt,
R. G. Roble,
C. E. Randall,
P. F. Bernath,
B. Funke,
M. López-Puertas,
S. Versick,
G. P. Stiller,
A. J. Tylka,
E. L. Fleming
Atmos. Chem. Phys. 01/2011; 11:6153-6166.
-
C. H. Jackman,
B. Funke,
M. Lopez-Puertas,
S. Versik,
G. P. Stiller,
A. J. Tylka, D. R. Marsh,
F. M. Vitt,
R. R. Garcia,
C. E. Randall,
E. L. Fleming
[show abstract]
[hide abstract]
ABSTRACT: Solar eruptions in early 2005 led to a substantial barrage of charged
particles on the Earth’s atmosphere in a few separate events
during the January 16-21 period. Significant production of OH [Verronen
et al. 2006] and destruction of ozone [Verronen et al. 2006; Seppala et
al. 2006] have been documented due to the enhanced solar proton flux in
January 2005. These solar proton events (SPEs) also led to the
production of NOx (NO, NO2), when the protons and associated secondary
electrons dissociated molecular nitrogen (N2). Our simulations with the
Whole Atmosphere Community Climate Model (WACCM) show that mesospheric
NOx is enhanced in both the polar Southern (greater than 10 ppbv) and
Northern (greater than 40 ppbv) Hemispheres. Envisat MIPAS measurements
of nighttime NO2 for the Northern Hemisphere are in reasonable agreement
with these predictions. Such enhancements are considerable for the
mesosphere and led to increases in Northern Hemisphere polar upper
stratospheric odd nitrogen (NOy) greater than 20% in February and March
2005. The largest ground level enhancement (GLE) of solar cycle 23
occurred on January 20, 2005 with a neutron monitor increase of about
270% [Gopalswamy et al. 2005]. Using results from a recent analysis of
the proton spectrum derived from neutron-monitor data [Tylka &
Dietrich 2009], we found that protons of energies 300 to 20,000 MeV, not
normally included in our computations, led to enhanced stratospheric NOy
of less than 1% as a result of this GLE. Thus, the primary impact of the
January 2005 solar events on the middle atmosphere was through protons
with energies less than 300 MeV. This presentation will show both short-
and longer-term changes due to the January 2005 solar protons.
Gopalswamy, N., et al., Coronal mass ejections and ground level
enhancements, 29th International Cosmic Ray Conference Pune, 1, 169-173,
2005. Seppala, A., et al., Destruction of the tertiary ozone maximum
during a solar proton event, Geophys. Res. Lett., 33, L07804,
doi:10.1029/2005GL025571, 2006. Tylka, A.J. & W.F. Dietrich, A new
and comprehensive analysis of proton spectra in ground-level enhanced
(GLE) solar particle events, 31st International Cosmic Ray Conference
Lodz, paper 0273, 2009. Verronen, P. T., et al., Production of odd
hydrogen in the mesosphere during the January 2005 solar proton event,
Geophys Res. Lett., 33, L24811, doi:10.1029/2006GL028115, 2006.
AGU Fall Meeting Abstracts. 11/2009; -1:1245.
-
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.
-
C. H. Jackman, D. R. Marsh,
F. M. Vitt,
R. R. Garcia,
E. L. Fleming,
G. J. Labow,
C. E. Randall,
López-Puertas M,
Funke B,
T. von Clarmann,
G. P. Stiller
[show abstract]
[hide abstract]
ABSTRACT: Solar eruptions sometimes produce protons, which impact the Earth's atmosphere. These solar proton events (SPEs) generally last a few days and produce high energy particles that precipitate into the Earth's atmosphere. The protons cause ionization and dissociation processes that ultimately lead to an enhancement of odd-hydrogen and odd-nitrogen in the polar cap regions (>60° geomagnetic latitude). We have used the Whole Atmosphere Community Climate Model (WACCM3) to study the atmospheric impact of SPEs over the period 1963–2005. The very largest SPEs were found to be the most important and caused atmospheric effects that lasted several months after the events. We present the short- and medium-term (days to a few months) atmospheric influence of the four largest SPEs in the past 45 years (August 1972; October 1989; July 2000; and October–November 2003) as computed by WACCM3 and observed by satellite instruments. Polar mesospheric NOx (NO+NO2) increased by over 50 ppbv and mesospheric ozone decreased by over 30% during these very large SPEs. Changes in HNO3, N2O5, ClONO2, HOCl, and ClO were indirectly caused by the very large SPEs in October–November 2003, were simulated by WACCM3, and previously measured by Envisat Michelson Interferometer for Passive Atmospheric Sounding (MIPAS). WACCM3 output was also represented by sampling with the MIPAS averaging kernel for a more valid comparison. Although qualitatively similar, there are discrepancies between the model and measurement with WACCM3 predicted HNO3 and ClONO2 enhancements being smaller than measured and N2O5 enhancements being larger than measured. The HOCl enhancements were fairly similar in amounts and temporal variation in WACCM3 and MIPAS. WACCM3 simulated ClO decreases below 50 km, whereas MIPAS mainly observed increases, a very perplexing difference. Upper stratospheric and lower mesospheric NOx increased by over 10 ppbv and was transported during polar night down to the middle stratosphere in several weeks past the SPE. The WACCM3 simulations confirmed the SH HALOE observations of enhanced NOx in September 2000 as a result of the July 2000 SPE and the NH SAGE II observations of enhanced NO2 in March 1990 as a result of the October 1989 SPEs.
Atmospheric Chemistry and Physics. 01/2008;
-
Tourpali K,
A. F. Bais,
Kazantzidis A,
C. S. Zerefos,
Akiyoshi H,
Austin J,
Brühl C,
Butchart N,
M. P. Chipperfield,
Dameris M, [......],
M. A. Giorgetta,
D. E. Kinnison,
Mancini E, D. R. Marsh,
Nagashima T,
Pitari G,
D. A. Plummer,
Rozanov E,
Shibata K,
Tian W
[show abstract]
[hide abstract]
ABSTRACT: We have used total ozone columns and vertical profiles of ozone and temperature from 11 coupled Chemistry-Climate Models (CCMs) to project future solar ultraviolet radiation levels at the surface in the 21st century. The CCM simulations are used as input to a radiative transfer model for the simulation of the corresponding future UV irradiance levels under cloud free conditions, presented here as time series of monthly erythemal irradiance received at the surface during local noon covering 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 ozone recovery, at rates which are larger in the first half of the 21st century, compared to the period up to 2100. The magnitude of these decreases varies with latitude and is more pronounced at areas where ozone has been depleted most considerably after 1980. Over midlatitudes surface erythemal irradiance decreases between 5 and 15% by 2100 relative to 2000, while at the southern high latitudes these changes are twice as much. Climate change may affect future cloudiness, surface reflectivity and tropospheric aerosol loading, the effects of which are not included in this study. Therefore, the actual changes in future UV radiation are likely to change accordingly in the areas affected.
Atmospheric Chemistry and Physics Discussions. 01/2008;
-
[show abstract]
[hide abstract]
ABSTRACT: 1] The NCAR Whole Atmosphere Community Climate Model, version 3 (WACCM3), is used to study the atmospheric response from the surface to the lower thermosphere to changes in solar and geomagnetic forcing over the 11-year solar cycle. WACCM3 is a general circulation model that incorporates interactive chemistry that solves for both neutral and ion species. Energy inputs include solar radiation and energetic particles, which vary significantly over the solar cycle. This paper presents a comparison of simulations for solar cycle maximum and solar cycle minimum conditions. Changes in composition and dynamical variables are clearly seen in the middle and upper atmosphere, and these in turn affect terms in the energy budget. Generally good agreement is found between the model response and that derived from satellite observations, although significant differences remain. A small but statistically significant response is predicted in tropospheric winds and temperatures which is consistent with signals observed in reanalysis data sets.
J. Geophys. Res. 01/2007; 112.
-
[show abstract]
[hide abstract]
ABSTRACT: Solar eruptions sometimes produce protons, which impact the Earth's atmosphere. These solar proton events (SPEs) generally last a few days and produce high energy particles that precipitate into the Earth's atmosphere. The protons cause ionization and dissociation processes that ultimately lead to an enhancement of odd-hydrogen and odd-nitrogen in the polar cap regions (>60° geomagnetic latitude). We have used the Whole Atmosphere Community Climate Model (WACCM3) to study the atmospheric impact of SPEs over the period 1963–2005. The very largest SPEs were found to be the most important and caused atmospheric effects that lasted several months to years after the events. We present the short- and medium-term (days to a few months) atmospheric influence of the four largest SPEs in the past 45 years (August 1972; October 1989; July 2000; and October–November 2003) as computed by WACCM3 and observed by satellite instruments. The polar effects can be summarized as follows: 1) Mesospheric NOx (NO+NO2) increased by over 50 ppbv and mesospheric ozone decreased by over 30% during these very large SPEs; 2) upper stratospheric and lower mesospheric NOx increased by over 10 ppbv and was transported during polar night down to the middle stratosphere in a few weeks; 3) mid- to upper stratospheric ozone decreased over 20%; and 4) enhancements of HNO3, HOCl, ClO, ClONO2, and N2O5 were indirectly caused by the very large SPEs, although the model results suggest impacts at higher altitudes than indicated by the measurements for the October–November 2003 SPE period.
Atmospheric Chemistry and Physics Discussions. 01/2007;
-
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.
-
[show abstract]
[hide abstract]
ABSTRACT: Polyphenol oxidase (PPO) activity in finely milled wholewheat and milling fractions has been studied by measuring O2 consumption of aqueous suspensions after addition of catechol as substrate. Wheat bran contained higher levels of PPO than did wholemeal; white flour contained relatively low levels, and no PPO activity was detected in a germ-rich milling fraction. In wholemeal, 72% of the total PPO activity remained in a washed, insoluble residue after extraction with aqueous buffer solutions. Although treatment of wholemeal with solutions containing sodium dodecylsulphate, Triton X-100 or lactic acid caused substantial increases in the total PPO activity measured, most of this remained in the insoluble residue. The results are discussed in relation to a widely used alternative assay for PPO activity based on spectrophotometric measurements with aqueous extracts of ground wholewheat.
Journal of Cereal Science.
-
[show abstract]
[hide abstract]
ABSTRACT: We present results of an investigation aimed at characterizing the effects of oceanic impacts of 500 m and 1 km diameter asteroids on the lower and middle atmosphere, estimating ozone loss and potential danger from UV radiation at the Earth's surface. Little work has been done so far to assess the atmospheric perturbation from the impact of objects in this size range, even though their sizes are close to the threshold for causing global environmental effects. In particular, at the Earth's surface oceanic impacts are twice more likely to occur than land impacts. This work represents the first attempt at combining impact simulations with a three-dimensional shock physics code (SOVA), and atmospheric simulations using the general circulation model with interactive chemistry WACCM. SOVA simulations provided an estimate of the amount and state of material ejected into the atmosphere by the impacts. Estimated water vapor in the upper atmosphere was then introduced in the initial conditions for the WACCM simulations that modeled the subsequent perturbation of atmospheric chemistry Final estimates of the change over time in UV flux at the surface due to the impact-induced ozone change are then carried out using the TUV radiative transfer model. The results suggest that mid-latitude oceanic impacts of 1 km asteroids can produce a significant, global perturbation of upper atmospheric chemistry, including multi-year global ozone depletion comparable to ozone hole records registered in the mid-1990 s. Asteroids 500 m in diameter cause limited perturbations of upper atmospheric chemistry with significant ozone depletion confined to the hemisphere in which the impact occurred. Impact-induced ozone depletion affects UV irradiance at the Earth's surface, resulting in levels of UV-B irradiance that can be dangerous for living organisms, and, in the tropics and initial midlatitude summers, far exceed levels currently experienced anywhere on Earth.
Earth and Planetary Science Letters.
-
Earth and Planetary Science Letters, v.299, 263-272 (2010).
-
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).
-
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).
-
D. E. Kinnison,
G. P. Brasseur,
S. Walter,
R. R. Garcia, D. R. Marsh,
F. Sassi,
V. L. Harvey,
C. E. Randall,
L. Emmons,
J. F. Lamarque,
P. Hess,
J. J. Orlando,
X. X. Tie,
W. Randel,
L. L. Pan,
A. Gettelman,
C. Granier,
T. Diehl,
U. Niemeier,
A. J. Simmons
[show abstract]
[hide abstract]
ABSTRACT: The Model for Ozone and Related Chemical Tracers, version 3 (MOZART-3), which represents the chemical and physical processes from the troposphere through the lower mesosphere, was used to evaluate the representation of long- lived tracers and ozone using three different meteorological fields. The meteorological fields are based on (1) the Whole Atmosphere Community Climate Model, version 1b (WACCM1b), (2) the European Centre for Medium- Range Weather Forecasts (ECMWF) operational analysis, and (3) a new reanalysis for year 2000 from ECMWF called EXP471. Model-derived tracers (methane, water vapor, and total inorganic nitrogen) and ozone are compared to data climatologies from satellites. Model mean age of air was also derived and compared to in situ CO2 and SF6 data. A detailed analysis of the chemical fields simulated by MOZART-3 shows that even though the general features characterizing the three dynamical sets are rather similar, slight differences in winds and temperature can produce substantial differences in the calculated distributions of chemical tracers. The MOZART-3 simulations that use meteorological fields from WACCM1b and ECMWF EXP471 represented best the distribution of long-lived tracers and mean age of air in the stratosphere. There was a significant improvement using the ECMWF EXP471 reanalysis data product over the ECMWF operational data product. The effect of the quasi- biennial oscillation circulation on long- lived tracers and ozone is examined.
Journal of Geophysical Research - Atmospheres, v.112 (2007).
-
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.
-
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).
