Investigation of direct solar proton impact on Arctic stratospheric ozone

2021 ◽  
Author(s):  
Jia Jia ◽  
Antti Kero ◽  
Niilo Kalakoski ◽  
Monika E. Szeląg ◽  
Pekka T. Verronen
Keyword(s):  
Climate Model ◽  
Model Simulation ◽  
Stratospheric Ozone ◽  
Individual Case ◽  
Solar Proton ◽  
Observation Data ◽  
Ozone Level ◽  
Superposed Epoch Analysis ◽  
Average Decrease ◽  
The Individual

<p>Recent studies reported up to a 10 % average decrease of lower stratospheric ozone at ∼ 20 km altitude following solar proton events (SPEs), based on superposed epoch analysis (SEA) of ozonesonde anomalies. Our study uses 49 SPEs that occurred after the launch of Aura MLS (2004–now) and 177 SPEs that occurred in the WACCM-D (Whole Atmosphere Community Climate Model with D-region ion chemistry) simulation period (1989–2012) to evaluate Arctic polar atmospheric ozone changes following SPEs. At the mesospheric altitudes a statistically significant ozone depletion is present. At the lower stratosphere (<25 km), SEA of the satellite dataset provides no solid evidence of any average direct SPE impact on ozone. In the individual case studies, we find only one potential case (January 2005) in which the lower-stratospheric ozone level was significantly decreased after the SPE onset (in both model simulation and MLS observation data). However, similar decreases could not be identified in other SPEs of similar or larger magnitude. We find a very good overall consistency between WACCM-D simulations and MLS observations of SPE-driven ozone anomalies both on average and for the individual cases, including case in January 2005.</p>

scholarly journals Is there a direct solar proton impact on lower-stratospheric ozone?

2020 ◽  
Vol 20 (23) ◽  
pp. 14969-14982
Author(s):  
Jia Jia ◽  
Antti Kero ◽  
Niilo Kalakoski ◽  
Monika E. Szeląg ◽  
Pekka T. Verronen
Keyword(s):  
Ozone Depletion ◽  
Climate Model ◽  
Model Simulation ◽  
Stratospheric Ozone ◽  
Solar Proton ◽  
Special Focus ◽  
Observation Data ◽  
Ozone Level ◽  
Superposed Epoch Analysis ◽  
The Individual

Abstract. We investigate Arctic polar atmospheric ozone responses to solar proton events (SPEs) using MLS (Microwave Limb Sounder) satellite measurements (2004–now) and WACCM-D (Whole Atmosphere Community Climate Model) simulations (1989–2012). Special focus is on lower-stratospheric (10–30 km) ozone depletion that has been proposed earlier based on superposed epoch analysis (SEA) of ozonesonde anomalies (up to 10 % ozone decrease at ∼ 20 km). SEA of the satellite dataset provides no solid evidence of any average SPE impact on the lower-stratospheric ozone, although at the mesospheric altitudes a statistically significant ozone depletion is present. In the individual case studies, we find only one potential case (January 2005) in which the lower-stratospheric ozone level was significantly decreased after the SPE onset (in both model simulation and MLS observation data). However, similar decreases could not be identified in other SPEs of similar or larger magnitude. Due to the input proton energy threshold of > 300 MeV, the WACCM-D model can only detect direct proton effects above 25 km, and simulation results before the Aura MLS era indicate no significant effect on the lower-stratospheric ozone. However, we find a very good overall consistency between WACCM-D simulations and MLS observations of SPE-driven ozone anomalies both on average and for the individual cases including January 2005.

scholarly journals Is there a direct solar proton impact on lower stratospheric ozone?

2020 ◽  
Author(s):  
Jia Jia ◽  
Antti Kero ◽  
Niilo Kalakoski ◽  
Monika E. Szeląg ◽  
Pekka T. Verronen
Keyword(s):  
Ozone Depletion ◽  
Stratospheric Ozone ◽  
Individual Case ◽  
Solar Proton ◽  
Special Focus ◽  
Ozone Level ◽  
Superposed Epoch Analysis ◽  
Potential Case ◽  
Epoch Analysis ◽  
The Individual

Abstract. We investigate Arctic polar atmospheric ozone responses to Solar Proton Events (SPEs) using MLS satellite measurements (2004–now) and WACCM-D simulations (1989–2012). Special focus is on lower stratospheric ozone depletion that has been proposed earlier based on superposed epoch analysis of ozonesonde anomalies (up to 10 % ozone decrease). Superposed Epoch Analysis (SEA) of the satellite dataset provides no evidence of any average SPE impact on the lower stratospheric ozone, although at the mesospheric altitudes a statistically significant ozone depletion is present. In the individual case studies, we find only one potential case (January 2005) in which the lower stratospheric ozone level was significantly decreased after the SPE onset. However, similar decreases could not be identified in other SPEs of similar or larger magnitude. We find a very good overall consistency between SPE-driven ozone anomalies derived from the WACCM-D model simulations and the Aura MLS data. The simulation results before the Aura MLS era indicate no significant effect on the lower stratospheric ozone either. As a conclusion, the SPE has a zero direct impact on the lower stratospheric ozone.

scholarly journals The Diurnal Variation in Stratospheric Ozone from MACC Reanalysis, ERA-Interim, WACCM, and Earth Observation Data: Characteristics and Intercomparison

Atmosphere ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 625
Author(s):  
Ansgar Schanz ◽  
Klemens Hocke ◽  
Niklaus Kämpfer ◽  
Simon Chabrillat ◽  
Antje Inness ◽  
...  
Keyword(s):  
Diurnal Variation ◽  
Climate Model ◽  
Stratospheric Ozone ◽  
Polar Vortex ◽  
Model Systems ◽  
Atmospheric Composition ◽  
The Arctic ◽  
Observation Data ◽  
High Latitudes ◽  
Free Running

In this study, we compare the diurnal variation in stratospheric ozone of the MACC (Monitoring Atmospheric Composition and Climate) reanalysis, ECMWF Reanalysis Interim (ERA-Interim), and the free-running WACCM (Whole Atmosphere Community Climate Model). The diurnal variation of stratospheric ozone results from photochemical and dynamical processes depending on altitude, latitude, and season. MACC reanalysis and WACCM use similar chemistry modules and calculate a similar diurnal cycle in ozone when it is caused by a photochemical variation. The results of the two model systems are confirmed by observations of the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) experiment and three selected sites of the Network for Detection of Atmospheric Composition Change (NDACC) at Mauna Loa, Hawaii (tropics), Bern, Switzerland (midlatitudes), and Ny-Ålesund, Svalbard (high latitudes). On the other hand, the ozone product of ERA-Interim shows considerably less diurnal variation due to photochemical variations. The global maxima of diurnal variation occur at high latitudes in summer, e.g., near the Arctic NDACC site at Ny-Ålesund, Svalbard. The local OZORAM radiometer observes this effect in good agreement with MACC reanalysis and WACCM. The sensed diurnal variation at Ny-Ålesund is up to 8% (0.4 ppmv) due to photochemical variations in summer and negligible during the dynamically dominated winter. However, when dynamics play a major role for the diurnal ozone variation as in the lower stratosphere (100–20 hPa), the reanalysis models ERA-Interim and MACC which assimilate data from radiosondes and satellites outperform the free-running WACCM. Such a domain is the Antarctic polar winter where a surprising novel feature of diurnal variation is indicated by MACC reanalysis and ERA-Interim at the edge of the polar vortex. This effect accounts for up to 8% (0.4 ppmv) in both model systems. In summary, MACC reanalysis provides a global description of the diurnal variation of stratospheric ozone caused by dynamics and photochemical variations. This is of high interest for ozone trend analysis and other research which is based on merged satellite data or measurements at different local time.

scholarly journals APPLICABILITY OF D4PDF DATASET TO GLOBAL STOCHASTIC TROPICAL CYCLONE MODEL

2020 ◽  
pp. 26
Author(s):  
Sota Nakajo ◽  
Jinji Umeda ◽  
Nobuhito Mori
Keyword(s):  
Tropical Cyclone ◽  
Climate Model ◽  
Model Simulation ◽  
Global Climate ◽  
Global Climate Model ◽  
Observation Data ◽  
Change Rate ◽  
Regional Area ◽  
Global Climate Model Simulation ◽  
Disaster Event

Disaster damage caused by tropical cyclone has grown every year. However, our experience of tropical cyclone is not enough to evaluate very low frequent and catastrophic disaster event. Stochastic tropical cyclone model has been used for assessment of tropical cyclone disaster. Global stochastic model was improved by using a lot of ensemble Global Climate Model simulation data (d4PDF) instead of limited number of observation data. The model bias included d4PDF was corrected by each regional grid by simple statistical method and interpolation. The accuracy of new model was verified at representative regional area in different basins. Generally, the improvement is remarkable where tropical cyclones rarely passed. The variation of joint PDF of tropical cyclone change rate between previous model and present model agree with model improvement. As an example of application, the frequencies of strong tropical cyclone events of two cases were estimated.

scholarly journals Detectability of the Impacts of Ozone Depleting Substances and Greenhouse Gases upon Stratospheric Ozone Accounting for Nonlinearities in Historical Forcings

2017 ◽  
Author(s):  
Justin Bandoro ◽  
Susan Solomon ◽  
Benajmin D. Santer ◽  
Douglas E. Kinnison ◽  
Michael J. Mills
Keyword(s):  
Greenhouse Gases ◽  
Climate Model ◽  
Linear Trend ◽  
Stratospheric Ozone ◽  
Global Changes ◽  
Response Patterns ◽  
Pattern Similarity ◽  
Ozone Depleting Substances ◽  
The Individual ◽  
Observational Record

Abstract. We perform a formal attribution study of upper and lower stratospheric ozone changes using observations together with simulations from the Whole Atmosphere Community Climate Model. Historical model simulations were used to estimate the zonal-mean response patterns (fingerprints) to combined forcing by ozone depleting substances (ODS) and well-mixed greenhouse gases (GHG), as well as to the individual forcing by each factor. Trends in the similarity between the searched-for fingerprints and homogenized observations of stratospheric ozone were compared to trends in pattern similarity between the fingerprints and the internally and naturally generated variability inferred from long control runs. This yields estimated signal-to-noise (S/N) ratios for each of the three fingerprints (ODS, GHG, and ODS+GHG). In both the upper stratosphere (defined in this paper as 1 to 10 hPa) and lower stratosphere (40 to 100 hPa), the spatial fingerprints of the ODS+GHG and ODS only patterns were consistently detectable not only during the era of maximum ozone depletion, but also throughout the observational record (1984–2016). Furthermore, we develop a fingerprint attribution method to account for forcings whose time evolutions are markedly nonlinear over the observational record. When the nonlinearity of the time evolution of the ODS and ODS+GHG signals are used in the trend regression, we find that the S/N ratios obtained with the stratospheric ODS and ODS+GHG fingerprints are enhanced relative to standard linear trend analysis. With this method, the complete observational record can be used in the S/N analysis, without applying piece-wise linear regression and introducing arbitrary break points. The GHG-driven fingerprint of ozone changes was not statistically identifiable in the either the upper or lower stratospheric SWOOSH data, irrespective of the method used. Use of the nonlinear signal method, instead of directly operating on ozone trends, also reduces the detection time – the estimate of the date at which ODS and GHG impacts on ozone can be formally identified. In the WACCM future simulations, the GHG signal is statistically identifiable between 2020–2030. Our findings demonstrate the importance of continued stratospheric ozone monitoring to improve estimates of the contributions of ODS and GHG forcing to global changes in stratospheric ozone.

The MIPAS climatology of BrONO2: a test for stratospheric bromine chemistry

2021 ◽  
Author(s):  
Michael Höpfner ◽  
Oliver Kirner ◽  
Gerald Wetzel ◽  
Björn-Martin Sinnhuber ◽  
Florian Haenel ◽  
...  
Keyword(s):  
Cross Sections ◽  
Climate Model ◽  
Model Simulation ◽  
Stratospheric Ozone ◽  
Michelson Interferometer ◽  
Emission Spectra ◽  
Night Time ◽  
Mixing Ratios ◽  
Independent Information ◽  
Independent Observations

<p>Besides chlorine, bromine is the major halogen species affecting stratospheric ozone with both anthropogenic and natural sources. Despite the significantly lower concentrations of bromine in the atmosphere, its potential for ozone depletion is similar to that of chlorine. An important prerequisite for the effectiveness of bromine ozone destruction cycles versus those of chlorine is the larger instability of bromine reservoir gases, especially the faster photolysis of bromine nitrate (BrONO<sub>2</sub>) compared to chlorine nitrate (ClONO<sub>2</sub>). With BrONO<sub>2</sub> abundances in the stratosphere available from observations, (1) homogeneous, heterogeneous as well as photochemical processes involving bromine as implemented in atmospheric models can be assessed, and (2) independent information on the total stratospheric bromine content can be gained which is important, e.g. to analyse the amount of short-lived bromocarbons entering the stratosphere.</p><p>The first detection of BrONO<sub>2</sub> in the atmosphere had been achieved by analysis of infrared limb-emission spectra from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on the Envisat satellite (doi: 10.5194/acp-9-1735-2009). On availability of improved infrared cross-sections, this was followed by the analysis of the behaviour of BrONO<sub>2</sub> during sunrise and sunset through MIPAS balloon observations (doi: 10.5194/acp-17-14631-2017). Here we present a novel dataset of global stratospheric BrONO<sub>2</sub> distributions based on the recently available MIPAS version 8 dataset of calibrated level-1b spectra. The altitude profiles of BrONO<sub>2</sub> volume mixing ratios are zonally averaged in 10° latitude and 3-day bins, separated between day- and night-time observations, with a vertical resolution of 3-8 km between 15 and 35 km altitude for the whole MIPAS period from July 2002 until April 2012. The typical characteristics of this new dataset will be discussed. Furthermore, we will compare it to a multi-annual simulation of the chemistry climate model EMAC. Specific differences between observation and model simulation of BrONO<sub>2</sub> will be highlighted and discussed by means of sensitivity 1-d model runs. Finally, a time series of the derived stratospheric Br<sub>y</sub> content normalized to the time of the entry into the stratosphere on basis of MIPAS age-of-air information will be discussed with regard to estimated uncertainties as well as independent observations.</p>

scholarly journals Reactive nitrogen (NO<sub><i>y</i></sub>) and ozone responses to energetic electron precipitation during Southern Hemisphere winter

2019 ◽  
Vol 19 (14) ◽  
pp. 9485-9494 ◽  
Author(s):  
Pavle Arsenovic ◽  
Alessandro Damiani ◽  
Eugene Rozanov ◽  
Bernd Funke ◽  
Andrea Stenke ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
Climate Model ◽  
Middle Atmosphere ◽  
Stratospheric Ozone ◽  
Energetic Electron ◽  
Polar Vortex ◽  
Solar Proton ◽  
Electron Precipitation ◽  
Reactive Nitrogen ◽  
High Electron

Abstract. Energetic particle precipitation (EPP) affects the chemistry of the polar middle atmosphere by producing reactive nitrogen (NOy) and hydrogen (HOx) species, which then catalytically destroy ozone. Recently, there have been major advances in constraining these particle impacts through a parametrization of NOy based on high-quality observations. Here we investigate the effects of low (auroral) and middle (radiation belt) energy range electrons, separately and in combination, on reactive nitrogen and hydrogen species as well as on ozone during Southern Hemisphere winters from 2002 to 2010 using the SOCOL3-MPIOM chemistry-climate model. Our results show that, in the absence of solar proton events, low-energy electrons produce the majority of NOy in the polar mesosphere and stratosphere. In the polar vortex, NOy subsides and affects ozone at lower altitudes, down to 10 hPa. Comparing a year with high electron precipitation with a quiescent period, we found large ozone depletion in the mesosphere; as the anomaly propagates downward, 15 % less ozone is found in the stratosphere during winter, which is confirmed by satellite observations. Only with both low- and middle-energy electrons does our model reproduce the observed stratospheric ozone anomaly.

Heavy rainfall and flood risk assessment method considering the future climate change

2020 ◽  
Author(s):  
Tomohito Yamada ◽  
Tsuyoshi Hoshino
Keyword(s):  
Heavy Rainfall ◽  
Flood Control ◽  
Climate Model ◽  
Model Simulation ◽  
Assessment Method ◽  
Future Climate ◽  
Future Climate Change ◽  
Observation Data ◽  
Risk Assessment Method ◽  
The Future

&lt;p&gt;Existing flood control plans have been implemented based on rainfall estimated from observation data. However, we have data from the past several decades. Thus, it is not enough to project future extreme events from existing observation data. Therefore, Japan has been created huge ensemble of high-resolution climate model simulation based on the laws of physics. The data consist of past and future climate situations (past climate: total 3,000 years, 4 K warmer climate: total 5,400 years). It has enabled to quantitatively evaluate the probability of heavy rainfall and flooding on the future 4K-warmed earth.&lt;/p&gt;&lt;p&gt;Moreover, we apply the statistical theory of extreme value to evaluate the probability of heavy rainfall and flooding in the future. The results from statistical method is equivalent to the results from the huge ensemble data from climate model. It supports Japanese governments in formulating and carrying out their adaptation plans.&lt;/p&gt;

scholarly journals Reactive nitrogen (NO<sub><i>y</i></sub>) and ozone responses to energetic electron precipitation during Southern Hemisphere winter

2018 ◽  
Author(s):  
Pavle Arsenovic ◽  
Alessandro Damiani ◽  
Eugene Rozanov ◽  
Bernd Funke ◽  
Andrea Stenke ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
Climate Model ◽  
Middle Atmosphere ◽  
Stratospheric Ozone ◽  
Energetic Electron ◽  
Polar Vortex ◽  
Solar Proton ◽  
Electron Precipitation ◽  
Reactive Nitrogen ◽  
High Electron

Abstract. Energetic particle precipitation (EPP) affects the chemistry of the polar middle atmosphere by producing reactive nitrogen (NOy) and hydrogen (HOx) species, which then catalytically destroy ozone. Recently, there have been major advances in constraining these particle impacts through a parametrization based on high quality observations. Here we investigate the effects of low (auroral) and middle (radiation belt) energy range electrons, separately and in combination, on reactive nitrogen and hydrogen species as well as on ozone during Southern Hemisphere winters from 2002 to 2010 using the chemistry-climate model SOCOL3-MPIOM. Our results show that, in absence of solar proton events, low energy electrons produce the majority of NOy in the polar mesosphere and stratosphere. In the polar vortex, NOy subsides and affects ozone at lower altitudes, down to 10 hPa. Comparing a year with high electron precipitation with a quiescent period, we found large ozone depletion in the mesosphere; as the anomaly propagates downward, 15 % less ozone is found in the stratosphere during winter, which is confirmed by satellite observations. Only with both low and middle energy electrons, our model reproduces the observed stratospheric ozone anomaly.

scholarly journals Statistical response of middle atmosphere composition to solar proton events in WACCM-D simulations: importance of lower ionospheric chemistry

2020 ◽  
Author(s):  
Niilo Kalakoski ◽  
Pekka T. Verronen ◽  
Annika Seppälä ◽  
Monika E. Szeląg ◽  
Antti Kero ◽  
...  
Keyword(s):  
Climate Model ◽  
Middle Atmosphere ◽  
Lower Ionosphere ◽  
Solar Proton ◽  
Atmospheric Effects ◽  
Ion Chemistry ◽  
Global Models ◽  
Superposed Epoch Analysis ◽  
D Region ◽  
Solar Proton Events

Abstract. Atmospheric effects of solar proton events (SPE) have been studied for decades, because their drastic impact can be used to test our understanding of upper stratospheric and mesospheric chemistry in the polar cap regions. For example, SPEs cause production of odd hydrogen and odd nitrogen, which leads to depletion of ozone in catalytic reactions, such that the effects are easily observed from satellites during the largest events. Until recently, the complexity of the ion chemistry in the lower ionosphere (i.e. in the D region) has restricted global models to simplified parameterizations of chemical impacts induced by energetic particle precipitation (EPP). Because of this restriction, global models have been unable to correctly reproduce some important effects, such as the increase of mesospheric HNO3 or the changes in chlorine species. Here we use simulations from the WACCM-D model, a variant of the Whole Atmosphere Community Climate Model, to study the statistical response of the atmosphere to the 66 largest SPEs that occurred in years 1989–2012. Our model includes a set of D-region ion chemistry, designed for a detailed representation of the atmospheric effects of SPEs and EPP in general. We use superposed epoch analysis to study changes in O3, HOx (OH + HO2), Clx (Cl + ClO), HNO3, NOx (NO + NO2) and H2O. Compared to the standard WACCM which uses an ion chemistry parameterization, WACCM-D produces a larger response in O3 and NOx, weaker response in HOx and introduces changes in HNO3 and Clx. These differences between WACCM and WACCM-D highlight the importance of including ion chemistry reactions in models used to study EPP.

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