edu.ucar.opensky::articles:26876 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-24T19:21:36.909193 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7q52trx https://doi.org/10.5683/SP2/BC4ATC https Related Dataset #1 Data Quality Flags for ACE-FTS Level 2 Version 4.1/4.2 Data Set https://doi.org/10.5065/D6RX99HX https Related Service #1 Cheyenne: SGI ICE XA Cluster N2O as a regression proxy for dynamical variability in stratospheric trace gas trends 2023-10-20T00:00:00Z publication https://n2t.org/ark:/85065/d7q52trx https://doi.org/10.5194/acp-23-13283-2023 Dubé, K. author Tegtmeier, S. author Bourassa, A. author Zawada, D. author Degenstein, D. author Sheese, P. E. author Walker, K. A. author Randel, William author UCAR/NCAR - Library publisher Trends in stratospheric trace gases like HCl, N2O, O3, and NOy show a hemispheric asymmetry over the last 2 decades, with trends having opposing signs in the Northern Hemisphere and Southern Hemisphere. Here we use N2O, a long-lived tracer with a tropospheric source, as a proxy for stratospheric circulation in the multiple linear regression model used to calculate stratospheric trace gas trends. This is done in an effort to isolate trends due to circulation changes from trends due to the chemical effects of ozone-depleting substances. Measurements from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) and the Optical Spectrograph and InfraRed Imager System (OSIRIS) are considered, along with model results from the Whole Atmosphere Community Climate Model (WACCM). Trends in HCl, O3, and NOy for 2004–2018 are examined. Using the N2O regression proxy, we show that observed HCl increases in the Northern Hemisphere are due to changes in the stratospheric circulation. We also show that negative O3 trends above 30 hPa in the Northern Hemisphere can be explained by a change in the circulation but that negative ozone trends at lower levels cannot. Trends in stratospheric NOy are found to be largely consistent with trends in N2O. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. None eng geoscientificInformation