With the launch of the novel Aeolus wind profiling mission, a wealth of direct wind and atmospheric backscatter profile observations has become available across the globe, revealing new information on atmospheric dynamics and optical properties to the benefit of a number of applications. These applications include, for example, improvements in numerical weather prediction (NWP), general circulation models (GCMs) and their included parameterized processes, such as land and ocean drag, convection, stratosphere–troposphere interaction and atmospheric waves, air quality and air pollution transport, etc. In this special issue, new data products and their validation as well as studies using the Aeolus data for application in meteorology, air quality, and climate studies are discussed. Topics vary from observation interpretation to GCM or NWP model diagnostics, parameterization, and data assimilation experiments. This is the first special issue on scientific analysis of Aeolus mission data, including inter-comparisons with different collocated wind profiling, aerosol and cloud in situ and remote-sensing measurements, and atmospheric models. Contributions concerning Aeolus data calibration, processing, and tools for data access and exploitation are also provided.

Initiated by the German research project ClimXtreme (https://climxtreme.net/index.php), but open to all relevant submissions, the objective of the inter-journal special issue "Past and future European atmospheric extreme events under climate change" is to compile research results and recent advances in research exploring if and how extreme weather events have changed in the past, and what is to be expected under future climate scenarios. The time span covers the past and present centuries. Foci are physical mechanisms, statistical assessments, and impact-prone processes. Research on physical mechanisms addresses understanding the relationship between the extreme events' occurrence and severity and their spatial and temporal environment, exploring how climate change influences their generation processes in the past and a prospective future. Statistical approaches related to data science make use of large heterogeneous observational and model output data, of both the past and future, or advanced statistical methods, such as attribution research. Impact-related research investigates factors modifying the relation of the extreme meteorological conditions and the outcome in terms of damage, as pre-conditioning mechanisms can change the resilience of society and ecosystems against extremes. Compound meteorological events can lead to damage with a combination of relatively weak extremes. The regional focus is on continental Europe and its marginal seas, including the Atlantic and Arctic regions as important interacting parts of the climate system. Authors are advised to choose the most appropriate journal for their papers, which in this inter-journal special issue are Hydrology and Earth System Sciences (HESS), Advances in Statistical Climatology, Meteorology and Oceanography (ASCMO), and Weather and Climate Dynamics (WCD).

The climate research community uses reanalyses widely to understand atmospheric processes and variability in the middle atmosphere, yet different reanalyses give very different results for the same diagnostics. For example, the global energy budget and hydrological cycle, the Brewer–Dobson circulation, stratospheric vortex weakening and intensification events, and large-scale wave activity at the tropical tropopause are known to differ among reanalyses.

The Stratosphere–troposphere Processes And their Role in Climate (SPARC) Reanalysis Intercomparison Project (S-RIP) began in 2013 as a coordinated activity to compare numerous key diagnostics in reanalysis data sets. The objectives of this project were

• to understand the causes of differences among reanalyses,
• to provide guidance on the appropriate usage of various reanalysis products in scientific studies,
• to contribute to future improvements in the reanalysis products by establishing collaborative links between the reanalysis centres and the SPARC community.

Phase 1 of the S-RIP project culminated with the publication of the S-RIP report (https://www.sparc-climate.org/sparc-report-no-10/) in January 2022 and a very successful special issue (https://acp.copernicus.org/articles/special_issue829.html) in ACP and ESSD with over 50 papers. Phase 1 was very successful in achieving the above objectives, and in doing so it taught us the value and importance of continuing reanalysis intercomparisons and communications between the reanalysis centres and the SPARC community. The above objectives thus remain the primary aims of S-RIP as the project moves into Phase 2.

This special issue is being initiated in the early stages of S-RIP Phase 2. The community is continuing to produce valuable papers including both updates using new reanalyses of diagnostics studied in Phase 1 and evaluation of diagnostics for processes and atmospheric regions that were not emphasized in Phase 1. This special issue welcomes papers both during this transitional period and in the following years of Phase 2 and both updates of work on processes studied in Phase 1 and new studies focused on additional processes and/or atmospheric regions.

The S-RIP project focuses primarily on differences among reanalyses, but studies that include operational analyses and studies comparing reanalyses with observations or model outputs are encouraged. Phase 1 of S-RIP emphasized diagnostics in the upper troposphere, stratosphere, and mesosphere. This special issue will collect research relevant to S-RIP, including broadening of the scope to, for example, evaluation of new reanalyses and of chemical reanalyses; more comprehensive evaluation of processes in the upper stratosphere and mesosphere; evaluation of tropospheric processes such as blocking, jet stream variations, and temperature anomalies; and more comprehensive evaluation of links between the stratospheric, upper tropospheric, and near-surface circulation and implications for extreme weather events.

All researchers are encouraged to submit to this issue regardless of past participation in S-RIP; we further encourage researchers to participate in and help guide S-RIP Phase 2.

The climate research community uses reanalyses widely to understand atmospheric processes and variability in the middle atmosphere, yet different reanalyses give very different results for the same diagnostics. For example, the global energy budget and hydrological cycle, the Brewer–Dobson circulation, stratospheric vortex weakening and intensification events, and large-scale wave activity at the tropical tropopause are known to differ among reanalyses.

The Stratosphere–troposphere Processes And their Role in Climate (SPARC) Reanalysis Intercomparison Project (S-RIP) began in 2013 as a coordinated activity to compare numerous key diagnostics in reanalysis data sets. The objectives of this project were

• to understand the causes of differences among reanalyses,
• to provide guidance on the appropriate usage of various reanalysis products in scientific studies,
• to contribute to future improvements in the reanalysis products by establishing collaborative links between the reanalysis centres and the SPARC community.

Phase 1 of the S-RIP project culminated with the publication of the S-RIP report (https://www.sparc-climate.org/sparc-report-no-10/) in January 2022 and a very successful special issue (https://acp.copernicus.org/articles/special_issue829.html) in ACP and ESSD with over 50 papers. Phase 1 was very successful in achieving the above objectives, and in doing so it taught us the value and importance of continuing reanalysis intercomparisons and communications between the reanalysis centres and the SPARC community. The above objectives thus remain the primary aims of S-RIP as the project moves into Phase 2.

This special issue is being initiated in the early stages of S-RIP Phase 2. The community is continuing to produce valuable papers including both updates using new reanalyses of diagnostics studied in Phase 1 and evaluation of diagnostics for processes and atmospheric regions that were not emphasized in Phase 1. This special issue welcomes papers both during this transitional period and in the following years of Phase 2 and both updates of work on processes studied in Phase 1 and new studies focused on additional processes and/or atmospheric regions.

The S-RIP project focuses primarily on differences among reanalyses, but studies that include operational analyses and studies comparing reanalyses with observations or model outputs are encouraged. Phase 1 of S-RIP emphasized diagnostics in the upper troposphere, stratosphere, and mesosphere. This special issue will collect research relevant to S-RIP, including broadening of the scope to, for example, evaluation of new reanalyses and of chemical reanalyses; more comprehensive evaluation of processes in the upper stratosphere and mesosphere; evaluation of tropospheric processes such as blocking, jet stream variations, and temperature anomalies; and more comprehensive evaluation of links between the stratospheric, upper tropospheric, and near-surface circulation and implications for extreme weather events.

All researchers are encouraged to submit to this issue regardless of past participation in S-RIP; we further encourage researchers to participate in and help guide S-RIP Phase 2.

Initiated by the German research project ClimXtreme (https://climxtreme.net/index.php), but open to all relevant submissions, the objective of the inter-journal special issue "Past and future European atmospheric extreme events under climate change" is to compile research results and recent advances in research exploring if and how extreme weather events have changed in the past, and what is to be expected under future climate scenarios. The time span covers the past and present centuries. Foci are physical mechanisms, statistical assessments, and impact-prone processes. Research on physical mechanisms addresses understanding the relationship between the extreme events' occurrence and severity and their spatial and temporal environment, exploring how climate change influences their generation processes in the past and a prospective future. Statistical approaches related to data science make use of large heterogeneous observational and model output data, of both the past and future, or advanced statistical methods, such as attribution research. Impact-related research investigates factors modifying the relation of the extreme meteorological conditions and the outcome in terms of damage, as pre-conditioning mechanisms can change the resilience of society and ecosystems against extremes. Compound meteorological events can lead to damage with a combination of relatively weak extremes. The regional focus is on continental Europe and its marginal seas, including the Atlantic and Arctic regions as important interacting parts of the climate system. Authors are advised to choose the most appropriate journal for their papers, which in this inter-journal special issue are Hydrology and Earth System Sciences (HESS), Advances in Statistical Climatology, Meteorology and Oceanography (ASCMO), and Weather and Climate Dynamics (WCD).

With the launch of the novel Aeolus wind profiling mission, a wealth of direct wind and atmospheric backscatter profile observations has become available across the globe, revealing new information on atmospheric dynamics and optical properties to the benefit of a number of applications. These applications include, for example, improvements in numerical weather prediction (NWP), general circulation models (GCMs) and their included parameterized processes, such as land and ocean drag, convection, stratosphere–troposphere interaction and atmospheric waves, air quality and air pollution transport, etc. In this special issue, new data products and their validation as well as studies using the Aeolus data for application in meteorology, air quality, and climate studies are discussed. Topics vary from observation interpretation to GCM or NWP model diagnostics, parameterization, and data assimilation experiments. This is the first special issue on scientific analysis of Aeolus mission data, including inter-comparisons with different collocated wind profiling, aerosol and cloud in situ and remote-sensing measurements, and atmospheric models. Contributions concerning Aeolus data calibration, processing, and tools for data access and exploitation are also provided.