Stratospheric temperature and ozone anomalies associated with the 2020 Australian New Year Fires

Abstract. The impact of changes in incoming solar irradiance on stratospheric ozone abundances should be included in climate model simulations to fully capture the atmospheric response to solar variability. This study presents the first systematic comparison of the solar-ozone response (SOR) during the 11 year solar cycle amongst different chemistry-climate models (CCMs) and ozone databases specified in climate models that do not include chemistry. We analyse the SOR in eight CCMs from the WCRP/SPARC Chemistry-Climate Model Initiative (CCMI-1) and compare these with three ozone databases: the Bodeker Scientific database, the SPARC/AC&C database for CMIP5, and the SPARC/CCMI database for CMIP6. The results reveal substantial differences in the representation of the SOR between the CMIP5 and CMIP6 ozone databases. The peak amplitude of theSOR in the upper stratosphere (1–5 hPa) decreases from 5 % to 2 % between the CMIP5 and CMIP6 databases. This difference is because the CMIP5 database was constructed from a regression model fit to satellite observations, whereas the CMIP6 database is constructed from CCM simulations, which use a spectral solar irradiance (SSI) dataset with relatively weak UV forcing. The SOR in the CMIP6 ozone database is therefore implicitly more similar to the SOR in the CCMI-1 models than to the CMIP5 ozone database, which shows a greater resemblance in amplitude and structure to the SOR in the Bodeker database. The latitudinal structure of the annual mean SOR in the CMIP6 ozone database and CCMI-1 models is considerably smoother than in the CMIP5 database, which shows strong gradients in the SOR across the midlatitudes owing to the paucity of observations at high latitudes. The SORs in the CMIP6 ozone database and in the CCMI-1 models show a strong seasonal dependence, including large meridional gradients at mid to high latitudes during winter; such seasonal variations in the SOR are not included in the CMIP5 ozone database. Sensitivity experiments with a global atmospheric model without chemistry (ECHAM6.3) are performed to assess the impact of changes in the representation of the SOR and SSI forcing between CMIP5 and CMIP6. The experiments show that the smaller amplitude of the SOR in the CMIP6 ozone database compared to CMIP5 causes a decrease in the modelled tropical stratospheric temperature response over the solar cycle of up to 0.6 K, or around 50 % of the total amplitude. The changes in the SOR explain most of the difference in the amplitude of the tropical stratospheric temperature response in the case with combined changes in SOR and SSI between CMIP5 and CMIP6. The results emphasise the importance of adequately representing the SOR in climate models to capture the impact of solar variability on the atmosphere. Since a number of limitations in the representation of the SOR in the CMIP5 ozone database have been identified, CMIP6 models without chemistry are encouraged to use the CMIP6 ozone database to capture the climate impacts of solar variability.

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Northern winter stratospheric temperature and ozone responses to ENSO inferred from an ensemble of Chemistry Climate Models

Atmospheric Chemistry and Physics ◽

10.5194/acp-9-8935-2009 ◽

2009 ◽

Vol 9 (22) ◽

pp. 8935-8948 ◽

Cited By ~ 42

Author(s):

C. Cagnazzo ◽

E. Manzini ◽

N. Calvo ◽

A. Douglass ◽

H. Akiyoshi ◽

...

Keyword(s):

Climate Models ◽

Southern Oscillation ◽

Polar Vortex ◽

Atmospheric Modeling ◽

Residual Circulation ◽

Model Simulations ◽

Enso Events ◽

Stratospheric Temperature ◽

The Mean ◽

Column Ozone

Abstract. The connection between the El Niño Southern Oscillation (ENSO) and the Northern polar stratosphere has been established from observations and atmospheric modeling. Here a systematic inter-comparison of the sensitivity of the modeled stratosphere to ENSO in Chemistry Climate Models (CCMs) is reported. This work uses results from a number of the CCMs included in the 2006 ozone assessment. In the lower stratosphere, the mean of all model simulations reports a warming of the polar vortex during strong ENSO events in February–March, consistent with but smaller than the estimate from satellite observations and ERA40 reanalysis. The anomalous warming is associated with an anomalous dynamical increase of column ozone north of 70° N that is accompanied by coherent column ozone decrease in the Tropics, in agreement with that deduced from the NIWA column ozone database, implying an increased residual circulation in the mean of all model simulations during ENSO. The spread in the model responses is partly due to the large internal stratospheric variability and it is shown that it crucially depends on the representation of the tropospheric ENSO teleconnection in the models.

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Stratospheric temperature monitoring using a vibrational Raman lidar : Part 1: aerosols and ozone interferences

Journal of Environmental Monitoring ◽

10.1039/b415299a ◽

2005 ◽

Vol 7 (4) ◽

pp. 357 ◽

Cited By ~ 9

Author(s):

Denis Faduilhe ◽

Philippe Keckhut ◽

Hassan Bencherif ◽

Laurent Robert ◽

Serge Baldy

Keyword(s):

Temperature Monitoring ◽

Raman Lidar ◽

Stratospheric Temperature

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On the design of practicable numerical experiments to investigate stratospheric temperature change

Atmospheric Science Letters ◽

10.1002/asl.101 ◽

2005 ◽

Vol 6 (2) ◽

pp. 123-127 ◽

Cited By ~ 3

Author(s):

Sylvia H. E. Hare ◽

L. J. Gray ◽

W. A. Lahoz ◽

A. O'Neill

Keyword(s):

Temperature Change ◽

Numerical Experiments ◽

Stratospheric Temperature

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Optimizing the Definition of a Sudden Stratospheric Warming

Journal of Climate ◽

10.1175/jcli-d-17-0648.1 ◽

2018 ◽

Vol 31 (6) ◽

pp. 2337-2344 ◽

Cited By ~ 19

Author(s):

Amy H. Butler ◽

Edwin P. Gerber

Keyword(s):

Stratospheric Warming ◽

Sudden Stratospheric Warming ◽

Systematic Analysis ◽

Wave Forcing ◽

Zonal Winds ◽

Stratospheric Temperature ◽

Stratospheric Wind ◽

Definition Of ◽

Access To Data ◽

The Continuum

Various criteria exist for determining the occurrence of a major sudden stratospheric warming (SSW), but the most common is based on the reversal of the climatological westerly zonal-mean zonal winds at 60° latitude and 10 hPa in the winter stratosphere. This definition was established at a time when observations of the stratosphere were sparse. Given greater access to data in the satellite era, a systematic analysis of the optimal parameters of latitude, altitude, and threshold for the wind reversal is now possible. Here, the frequency of SSWs, the strength of the wave forcing associated with the events, changes in stratospheric temperature and zonal winds, and surface impacts are examined as a function of the stratospheric wind reversal parameters. The results provide a methodical assessment of how to best define a standard metric for major SSWs. While the continuum nature of stratospheric variability makes it difficult to identify a decisively optimal threshold, there is a relatively narrow envelope of thresholds that work well—and the original focus at 60° latitude and 10 hPa lies within this window.

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Polar Stratospheric Clouds detection at Belgrano II Antarctic station from DOAS measurements

10.5194/egusphere-egu21-3054 ◽

2021 ◽

Author(s):

Laura Gómez Martín ◽

Daniel Toledo ◽

Margarita Yela ◽

Cristina Prados-Román ◽

José Antonio Adame ◽

...

Keyword(s):

Radiative Transfer ◽

Color Index ◽

Radiative Transfer Model ◽

Optical Absorption Spectroscopy ◽

Transfer Model ◽

Meteorological Model ◽

Weather Forecasts ◽

Stratospheric Temperature ◽

Stratospheric Clouds

Ground-based zenith DOAS (Differential Optical Absorption Spectroscopy) measurements have been used to detect and estimate the altitude of PSCs over Belgrano II Antarctic station during the polar sunrise seasons of 2018 and 2019. The method used in this work studies the evolution of the color index (CI) during twilights. The CI has been defined here as the ratio of the recorded signal at 520 and 420 nm. In the presence of PSCs, the CI shows a maximum at a given solar zenith angle (SZA). The value of such SZA depends on the altitude of the PSC. By using a spherical Monte Carlo radiative transfer model (RTM), the method has been validated and a function relating the SZA of the CI maximum and the PSC altitude has been calculated. Model simulations also show that PSCs can be detected and their altitude can be estimated even in presence of optically thin tropospheric clouds or aerosols. Our results are in good agreement with the stratospheric temperature evolution obtained through the ERA5 data reanalysis from the global meteorological model ECMWF (European Centre for Medium Range Weather Forecasts) and the PSCs observations from CALIPSO (Cloud-Aerosol-Lidar and Infrared Pathfinder Satellite Observations).The methodology used in this work could also be applied to foreseen and/or historical measurements obtained with ground-based spectrometers such e. g. the DOAS instruments dedicated to trace gas observation in Arctic and Antarctic sites. This would also allow to investigate the presence and long-term evolution of PSCs.Keywords: Polar stratospheric clouds; color index; radiative transfer model; visible spectroscopy.

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Ozone and temperature decadal trends in the stratosphere, mesosphere and lower thermosphere, based on measurements from SABER on TIMED

Annales Geophysicae ◽

10.5194/angeo-32-935-2014 ◽

2014 ◽

Vol 32 (8) ◽

pp. 935-949 ◽

Cited By ~ 19

Author(s):

F. T. Huang ◽

H. G. Mayr ◽

J. M. Russell ◽

M. G. Mlynczak

Keyword(s):

Stratospheric Ozone ◽

Lower Thermosphere ◽

Definitive Evidence ◽

Broadband Emission ◽

Stratospheric Temperature ◽

Temperature Trends ◽

Time Period ◽

Ozone Trends ◽

Ozone Trend ◽

The Tropics

Abstract. We have derived ozone and temperature trends from years 2002 through 2012, from 20 to 100 km altitude, and 48° S to 48° N latitude, based on measurements from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics (TIMED) satellite. For the first time, trends of ozone and temperature measured at the same times and locations are obtained, and their correlations should provide useful information about the relative importance of photochemistry versus dynamics over the longer term. We are not aware of comparable results covering this time period and spatial extent. For stratospheric ozone, until the late 1990s, previous studies found negative trends (decreasing amounts). In recent years, some empirical and modeling studies have shown the occurrence of a turnaround in the decreasing ozone, possibly beginning in the late 1990s, suggesting that the stratospheric ozone trend is leveling off or even turning positive. Our global results add more definitive evidence, expand the coverage, and show that at mid-latitudes (north and south) in the stratosphere, the ozone trends are indeed positive, with ozone having increased by a few percent from 2002 through 2012. However, in the tropics, we find negative ozone trends between 25 and 50 km. For stratospheric temperatures, the trends are mostly negatively correlated to the ozone trends. The temperature trends are positive in the tropics between 30 and 40 km, and between 20 and 25 km, at approximately 24° N and at 24° S latitude. The stratospheric temperature trends are otherwise mostly negative. In the mesosphere, the ozone trends are mostly flat, with suggestions of small positive trends at lower latitudes. The temperature trends in this region are mostly negative, showing decreases of up to ~ −3 K decade−1. In the lower thermosphere (between ~ 85 and 100 km), ozone and temperature trends are both negative. The ozone trend can approach ~ −10% decade−1, and the temperature trend can approach ~ −3 K decade−1. Aside from trends, these patterns of ozone–temperature correlations are consistent with previous studies of ozone and temperature perturbations such as the quasi-biennial (QBO) and semiannual (SAO) oscillations, and add confidence to the results.

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A Two-Season Impact Study of Radiative Forced Tropospheric Response to Stratospheric Initial Conditions Inferred From Satellite Radiance Assimilation

Climate ◽

10.3390/cli7090114 ◽

2019 ◽

Vol 7 (9) ◽

pp. 114

Author(s):

Min Shao ◽

Yansong Bao ◽

George P. Petropoulos ◽

Hongfang Zhang

Keyword(s):

Weather Forecasting ◽

Initial Conditions ◽

Stratospheric Ozone ◽

Wrf Model ◽

Lower Troposphere ◽

Short Wave ◽

Advanced Technology ◽

Short Term ◽

Radiative Processes ◽

Stratospheric Temperature

This study investigated the impacts of stratospheric temperatures and their variations on tropospheric short-term weather forecasting using the Advanced Research Weather Research and Forecasting (WRF-ARW) system with real satellite data assimilation. Satellite-borne microwave stratospheric temperature measurements up to 1 mb, from the Advanced Microwave Sounding Unit-A (AMSU-A), the Advanced Technology Microwave Sounder (ATMS), and the Special Sensor microwave Imager/Sounder (SSMI/S), were assimilated into the WRF model over the continental U.S. during winter and summer 2015 using the community Gridpoint Statistical Interpolation (GSI) system. Adjusted stratospheric temperature related to upper stratospheric ozone absorption of short-wave (SW) radiation further lead to vibration in downward SW radiation in winter predictions and overall reduced with a maximum of 5.5% reduction of downward SW radiation in summer predictions. Stratospheric signals in winter need 48- to 72-h to propagate to the lower troposphere while near-instant tropospheric response to the stratospheric initial conditions are observed in summer predictions. A schematic plot illustrated the physical processes of the coupled stratosphere and troposphere related to radiative processes. Our results suggest that the inclusion of the entire stratosphere and better representation of the upper stratosphere are important in regional NWP systems in short-term forecasts.

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