Probing the Suitability of Meridional Stratospheric Ozone Gradients for Inferring Interannual Variability and Trends of the Subtropical Jet Stream

Details

• Journal Title:
  Journal of Climate
• Personal Author:
  Harzer, Frederik ; Garny, Hella ; Davis, Sean ; Birner, Thomas
• NOAA Program & Office:
  OAR (Oceanic and Atmospheric Research) ; CSL (Chemical Sciences Laboratory)
• Description:
  Atmospheric jet streams belong to the most fundamental elements of the global general circulation system and are susceptible to climate change. Jet stream variability in our present climate is usually studied from modern reanalysis products, although uncertainties arise due to insufficiently strong constraints of the underlying global wind field by the available observational records, especially concerning their long-term trends. This motivates the use of observation-based metrics to track dynamical variability and historical trends. Here, we investigate how the zonal-mean ozone structure can be used to indirectly infer changes in the strength and latitudinal position of the subtropical jet streams (STJs). We mainly consider the winter-mean ozone distribution and analyze different diagnostics that track anomalies of the sharp ozone gradients near the subtropical tropopause, based on either vertically resolved or total-column ozone (TCO) fields. Using ERA5 reanalysis output, we find significant correspondence of these sharp ozone gradients with the STJ’s strength and location, with the jet acting as a tracer transport barrier and, hence, governing wave-induced horizontal ozone transport across the jet core. The ozone gradient metrics obtained from vertically resolved ozone observations agree well with ERA5 in more recent years when densely sampled satellite measurements were included. We furthermore obtain mostly consistent historical trend signals from both conventional STJ metrics from reanalyses and more independent TCO records. Chemistry–Climate Model Initiative phase 1 (CCMI-1) and CMIP6 climate simulations suggest a strong correspondence between changes in subtropical ozone gradient maxima and projected STJ trends under different climate forcing scenarios.
• Source:
  Journal of Climate, 38(11), 2571-2588
• DOI:
  https://doi.org/10.1175/JCLI-D-24-0530.1
• ISSN:
  0894-8755 ; 1520-0442
• Format:
  pdf
• Publisher:
  American Meteorological Society
• Document Type:
  Journal Article
• Rights Information:
  Other
• Compliance:
  Submitted
• Main Document Checksum:
  urn:sha-512:f34b69ce127df9d68ea5b0c57b0e42cf250962c3cb78b440ab725153d7878ddc9742ab2fe979b9a251bdb91f13c1ec8acea0afb414ceb822b3db224ba92874c3
• Download URL:
  https://repository.library.noaa.gov/view/noaa/71505/noaa_71505_DS1.pdf
• File Type:
  [PDF - 2.63 MB ]