The Goddard Space Flight Center (GSFC) two-dimensional (2D) model is
used in the Atmospheric Chemistry and Dynamics Branch to help
understand the physical and chemical processes related to ozone changes
in the stratosphere and mesosphere (middle atmosphere). The model
domain extends from the south pole to the north pole in latitude
and from the ground to about 90 kilometers in altitude. The model
includes chemistry (about 40 photodissociation processes and about
110 chemical reactions) involving 52 different atmospheric constituents,
vertical and meridional winds, and diffusion processes.
This computer model is used to simulate natural and humankind-related
changes in middle atmospheric ozone. Natural ozone changes that have been
studied include those related to the 27-day solar rotation, the 11-year
solar cycle, solar proton events, relativistic electron precipitations,
interannual dynamical variations, volcanic eruptions, supernovae
explosions, and gamma-ray bursts.
that have been studied include those related to the chlorofluorocarbon
and halon increases, the nuclear explosion tests in the early 1960s,
Space Shuttle and Titan IV rocket launches, a proposed fleet of high
speed civil transport planes that would fly in the stratosphere, and the
proposed test flights of the National Aerospace Plane.
The model simulation is a realization of our theory of middle
atmospheric processes. Comparison of the 2D model output
and observational data can therefore either support that theory
if there is a good agreement, or point to deficiencies that need to
be resolved if there are discrepancies. Sometimes the theoretical
understanding is lacking and the comparison serves to revise the
theory and the model. Disagreements between the model simulation
and data can also be due to problems with the data such as
remote sensing retrieval
errors. The iterative comparison and revision of models such as the
GSFC 2D model and observations is what drives middle atmospheric
Click here for full image (20 Kb)
Stratospheric ozone is affected by anthropogenically caused
chlorine and bromine increases, solar cycle ultraviolet flux variations,
and the changing sulfate aerosol abundance due to several volcanic eruptions.
A study was recently completed, which included all three of these variations,
with the GSFC 2D model to predict ozone variations over the 1979
to 1994 period. The model captures much of the variability and downward
trend in total ozone that is measured by the Total Ozone Mapping Spectrometer
(TOMS) instruments, on Nimbus 7 and on Meteor 3, over this time period.
The model simulations predict a decrease in total ozone
of about 4% from 1979 to 1994 due to the chlorine and bromine increases.
The changing sulfate aerosol abundances can also significantly affect total
ozone with the Mt. Pinatubo eruption computed to cause a decrease in
global ozone by about 3% in 1992. Solar ultraviolet flux variations
cause increases and decreases in total ozone with computed changes of
about 1% from solar maximum to minimum.
Model predictions for the future indicate that total ozone
should start to recover from its lowest levels by the late 1990's. Future
measurements of ozone are crucial to help quantify the recovery
For further discussion of past, present and future trends in ozone see
Jackman, et al. (J. Geophys. Res., 101, 28,753-28,767, 1996).
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Observations of ozone by the Solar Backscatter UltraViolet (SBUV) and
SBUV/2 instruments also indicate substantial changes in ozone during the
period January 1979 to December 1993. The percentage changes in
ozone over this time period are illustrated as trends per decade in
the top figure above.
These ozone changes are believed to be caused by the increasing chlorine
and bromine in the atmosphere over that 15 year time period from
humans' production of chlorofluorocarbons (CFCs) and halons. The
GSFC 2D model has been used to compute the ozone changes caused by
the humankind-produced CFCs and halons over the 1979-93 time period.
The decadal trends predicted from the GSFC 2D model over this time period
are given for two different model simulations (Models 1 and 2) in the
lower two figures. Model 1 uses standard chemistry while Model 2 includes
an added chemical reaction and leads to a smaller downward trend in the
upper stratosphere (35-50 km) than computed in Model 1. Both Models 1 and
2 have similarities with the trends calculated from the SBUV and SBUV/2
observations, however, both Models 1 or 2 reveal some differences when
compared to the observations.
(This is Figure 1 in Chandra et al. )
- Jackman, C. H., and R. D. McPeters, 2004: "The effect of
solar proton events on ozone and other constituents,"
Solar Variability and its Effects on Climate, Geophys.
Mon., 141, 305-319.
- Weisenstein, D. K., et al., 2004: "Separating chemistry and
transport effects in 2-D models,"
J. Geophys. Res., 109, 10.1029/2004JD004744.
- Melott, A. L., et al., 2004: "Did a gamma-ray burst initiate
the late ordovician mass extinction?,"
Int. J. Astrobiology, 3, 55-61.
- Gehrels, N., et al., 2003: "Ozone depletion from nearby
Astrophys. J., 585, 1169-1176.
- Miller, A. J., et al., 2002: "A cohesive total ozone data set
from the SBUV(2) satellite system,"
J. Geophys. Res., 107, 10.1029/2001JD000853.
- Fleming, E. L., et al., 2002: "Two-dimensional model
simulations of the QBO in ozone and tracers in the
J. Geophys. Res., 107, 10.1029/2001JD001146.
- Jackman, C. H., et al., 2001: "Northern Hemisphere atmospheric
effects due to the July 2000 solar proton event,"
Geophys. Res. Lett., 28, 2883-2886.
- Fleming, E. L., et al., 2001: "Sensitivity of tracers and a
stratospheric aircraft perturbation in two-dimensional model
J. Geophys. Res., 106, 14245-14264.
- Jackman, C. H., et al., 2000: "Influence of extremely large solar
proton events in a changing stratosphere,"
J. Geophys. Res., 105, 11659-11670.
- Weatherhead, E. C., et al., 2000: "Detecting the recovery of
total column ozone," J. Geophys. Res., 105,
- Vitt, F. M., et al., 2000: "Computed contributions to odd
nitrogen concentrations in the Earth's polar middle
atmosphere by energetic charged particles,"
J. Atmos. Solar-Terr. Phys., 62, 669-683.
- Vitt, F. M., et al., 2000: "A two-dimensional model of
thermospheric nitric oxide sources and their contributions
to the middle atmospheric chemical balance,"
J. Atmos. Solar-Terr. Phys., 62, 653-667.
- Fleming, E. L., et al., 1999: "Simulation of stratospheric tracers
using an improved empirically based two-dimensional model
transport," J. Geophys. Res., 104, 23911-23934.
- Considine, D. B., et al., 1999: "A Monte Carlo uncertainty analysis
of ozone trend predictions in a two-dimensional model,"
J. Geophys. Res., 104, 1749-1765.
- Jackman, C. H., et al., 1998: "A global modeling study of solid
rocket aluminum oxide emission effects on stratospheric
ozone," Geophys. Res. Lett., 25, 907-910.
- Danilin, M. Y., et al., 1998: "Aviation fuel tracer
simulation: Model intercomparison and implications,"
Geophys. Res. Lett., 25, 3947-3950.
- Considine, D. B., et al., 1998: "Interhemispheric asymmetry in
the 1 mbar O3 trend: An analysis using an interactive
zonal mean model and UARS data," J. Geophys. Res.,
- Roche, A. E., et al., 1998: "Distribution and seasonal
variation of CFCs in the stratosphere: Comparison of
satellite global data and a 2-D model,"
Adv. Space Rev., 21, 1383-1391.
- Miller, A. J., et al., 1997: "Information content
for ozone trends and solar responses in the
stratosphere from Umkehr and SBUV(2) satellite data,"
J. Geophys. Res., 102, 19257-19263.
- Chandra, S., et al., 1997: "The seasonal and long term changes
in mesospheric water vapor," Geophys. Res. Lett.,
- Chen, L, et al., 1997: "Sensitivity and uncertainty studies
of a two-dimensional middle atmospheric ozone model
to chemical reaction rates,"
J. Geophys. Res., 102, 16201-16214.
- Rosenfield, J. E., et al., 1997: "Stratopheric effects
of the Mt. Pinatubo aeorosl studied with a coupled
two-dimensional model," J. Geophys. Res.,
- Jackman, C. H., et al., 1996: "Past, present, and future
modeled ozone trends with comparisons to observed trends,"
J. Geophys. Res., 101, 28,753-28,767, 1996.
- Vitt, F. M., and C. H. Jackman, 1996: "A comparison of sources
of odd nitrogen production from 1974 through 1993 in the
Earth's middle atmosphere as calculated using a
two-dimensional model," J. Geophys. Res., 101,
- Jackman, C. H., et al., 1996: "The space shuttle's impact
on the stratosphere: An update,"
J. Geophys. Res., 101, 12,523-12,529, 1996.
- Jackman, C. H., et al., 1995: "Energetic particle
precipitation effects on odd nitrogen and ozone over the
solar cycle time scale," published in a
STEP Working Group 5 Report entitled "The Solar Cycle Variation in the
Stratosphere," Editor Lon L. Hood, Department of Planetary Sciences,
University of Arizona, Tucson, Arizona, 1995.
- Chandra, S., et al., 1995: "Recent trends in ozone in the upper
stratosphere: Implications for chlorine chemistry,"
Geophys. Res. Lett., 22, 843-846, 1995.
- Jackman, C. H., et al., 1995: "Two-dimensional and three-
simulations, measurements, and interpretation of the influence of the
October 1989 solar proton events on the middle atmosphere,"
J. Geophys. Res., 100, 11,641-11,660, 1995.
- Fleming, E. L, et al., 1995: "The middle atmospheric
response to short and
long term solar UV variations: analysis of observations and 2D model
results," J. Atmos. Terr. Phys., 57, 333-365, 1995.
- Considine, D. B., et al., 1995: "Sensitivity of two-dimensional model
predictions of ozone response to stratospheric aircraft: An
update," J. Geophys. Res.,100, 3075-3090, 1995.
- Considine, D. B., et al., 1994: "Effects of a polar stratospheric cloud
parameterization on ozone depletion due to stratospheric aircraft
in a two-dimensional model," J. Geophys. Res.,
99, 18879-18894, 1994.
- Jackman, C. H., 1994: "The impact of emissions from space transport
systems on the state of the atmosphere," in Proceedings of an
International Scientific Colloquium on Impact of Emissions from
Aircraft and Spacecraft Upon the Atmosphere, edited by U.
Schumann and D. Wurzel, pp. 366-371, 1994.
- Chandra, S., et al., 1993: "Chlorine catalyzed destruction of ozone:
Implications for ozone variability in the upper stratosphere,"
Geophys. Res. Lett., 20, pp. 351-354, 1993.
- Jackman, C. H., et al., 1992: "A simulation of the effects
of the National
aerospace plane testing on the stratosphere using a two-dimensional
model," in Proceedings of Fourth International Aerospace Planes
Conference, Am. Inst. of Aeronaut. and Astronaut., New
- Jackman, C. H., et al., 1991: "The influence of dynamics
model results: Simulations of 14C and stratospheric aircraft NOx
injections," J. Geophys. Res., 96, pp. 22,559-22,572,
- Kaye, J. A., et al., 1991: "Two-dimensional model calculation
containing reservoir species in the stratosphere," J. Geophys.
Res., 96, pp. 12,865-12,881, 1991.
- Jackman, C. H., et al., 1991: "Impact of interannual
of transport and temperature on ozone as computed using a two-
dimensional photochemical model," J. Geophys. Res., 96,
pp. 5073-5079, 1991.
- Jackman, C. H., et al., 1990: "Effect of solar proton events on the
middle atmosphere during the past two solar cycles as computed
using a two-dimensional model," J. Geophys. Res., 95,
pp. 7417-7428, 1990.
- Jackman, C. H., et al., 1989: "The sensitivity of total ozone and ozone
perturbation scenarios in a two-dimensional model due to
dynamical inputs," J. Geophys. Res., 94,
pp. 9873-9887, 1989.
- Douglass, A. R., et al., 1989: "Comparison of model
the odd nitrogen family with results transporting separate
odd nitrogen species," J. Geophys. Res., 94,
pp. 9862-9872, 1989.
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Last Updated: 9 December 2004
Author: Charles Jackman (email@example.com)
Web Curator: Leslie R. Lait (Hughes STX) (firstname.lastname@example.org)
Responsible NASA organization/official: Dr. P. K. Bhartia, Atmospheric Chemistry and Dynamics Branch/Head