HR: 11:40h
AN: A52A-04 INVITED     [Abstracts]
TI: Trends From the Long-Term Data Record and Models: What do They Tell us About our Ability to Predict Ozone Recovery?
AU: * Strahan, S E
EM: strahan@code916.gsfc.nasa.gov
AF: Goddard Earth Science and Technology Center/NASA GSFC, Code 613.3, Greenbelt, MD 20771 United States
AU: Stolarski, R S
EM: richard.stolarski@nasa.gov
AF: NASA Goddard Space Flight Center, Code 613.3, Greenbelt, MD 20771 United States
AU: Douglass, A R
EM: anne.r.douglass@nasa.gov
AF: NASA Goddard Space Flight Center, Code 613.3, Greenbelt, MD 20771 United States
AU: Steenrod, S D
EM: steenrod@code916.gsfc.nasa.gov
AF: Science Systems and Applications Inc./NASA GSFC, Code 613.3, Greenbelt, MD 20771 United States
AB: Our industrial society has performed an experiment on the stratospheric ozone layer over the last several decades. Initially there was the rapidly increasing release of halogen-containing compounds that carry chlorine and bromine to the stratosphere where they can cause a loss of ozone. The present part of this experiment is the implementation of the Montreal Protocol, which has led to a leveling off of halogen compounds and the beginning of their slow removal from the atmosphere. The observation and attribution of ozone response to the halogens has been a particularly difficult task because of the impact of solar cycle UV variation, two major volcanic eruptions, and interannual dynamic variability of the stratosphere. We have run 3 different 50-year simulations of the chemistry and transport of ozone and other constituents to help evaluate our understanding of the causes of ozone change and to assess our ability to predict ozone recovery with the removal of halogens. One simulation, using the Goddard chemical transport model (CTM), had interannual variability in the dynamics for the entire 50 years of simulation (1974-2022). The other two simulations used the Global Modeling Initiative (GMI) CTM with no dynamical variability: one used meteorology from a repeating warm Arctic winter and the other from a repeating cold Arctic winter. All simulations included the effects of aerosol surfaces from volcanic eruptions on chemical reactions as well as the variation in UV over the 11-year solar cycle. Differences between these simulations, and their comparisons to the long-term data record of the last several decades, allow us to ask questions about our understanding of the physical basis of the stratosphere's response to chemical change. We will show comparisons of the CTM calculations to the long-term data records from several sources. These include the SBUV/TOMS and ground-based total ozone column records, the SAGE and sonde ozone profile records, and the NDSC column records of key chemical constituents. The understanding that we gain from the combination of our model results and the long-term data record should lead to a better capability to predict how ozone will change in the future as chlorine and bromine are slowly removed from the stratosphere.
DE: 0340 Middle atmosphere--composition and chemistry
DE: 0341 Middle atmosphere--constituent transport and chemistry (3334)
DE: 3334 Middle atmosphere dynamics (0341, 0342)
DE: 3337 Numerical modeling and data assimilation
SC: Atmospheric Sciences [A]
MN: 2005 Joint Assembly