Ice cores provide a wealth of information about past climate and environmental conditions as well as direct records of the composition of the atmosphere on timescales from decades to hundreds of millennia. This comprises deep ice cores from both polar ice sheets and from high-altitude glaciers, with the latter responding most sensitively to human interaction with the Earth system.

In October 2022 the 3rd Open Science Conference of the International Partnerships of Ice Core Sciences (IPICS) takes place in Crans-Montana, Switzerland, providing the opportunity to document the status quo of ice core research including comparative studies on other climate archives and climate models in this joint special issue of Climate of the Past and The Cryosphere: "Ice core science at the three poles".

Potential topics of contributions include the latest results from polar and high-altitude ice cores, integrative science on ice cores, climate models and other climate archives, new proxies, and other ice-core-related technology developments. In particular, we invite ice-core-related contributions on the following themes.

1. Glacial–interglacial dynamics, interglacials, and sea level
2. Holocene and the last 2000-year climate forcings and variability
3. Progress in proxy development and interpretation
4. Ice dynamics, ice sheet instability, and geophysics
5. High-alpine ice cores
6. Ice biology, basal ice, and subglacial lakes
7. Pollution records
8. Advances in drilling engineering and borehole observations
9. Timescales and methods for ice dating
10. Rapid changes and teleconnections
11. Biogeochemical cycles in the Earth system – data and models
12. New ice archives
13. The Oldest Ice challenge and the preservation of climatic signals in the deepest ice.

Studies of ice extent, volume, and dynamics during former glaciations are important for understanding past climates and evolution of the Earth's surface, and they also provide analogies for present-day and future ice sheets and their subglacial environments. The special issue (SI) "Icy landscapes of the past" brings together contributions from four Copernicus journals (Climate of the Past, The Cryosphere, Earth Surface Dynamics, and Earth System Science Data), reflecting the interdisciplinarity across scientific communities working with former glaciations from the perspectives of palaeoclimatology, glacial geomorphology, Quaternary geology, and numerical modelling, among others. It provides a platform from which field-based reconstructions and model simulations can be compared and contrasted, teasing out complex couplings between the changing cryosphere-induced topographic, freshwater, and sea level forcings and climate states of both warmer and colder epochs of the past. Through this SI, we aim to piece together the growing knowledge about regional responses of different geographic regions to past climate changes to obtain a global picture, thereby fostering emerging collaborations between previously disconnected geoscientific disciplines. We welcome contributions that shed light on ancient and more recent glaciations on Earth and their interaction with other components of the Earth system.

The glacial–interglacial cyclicity of the climate system varied in the past, most notably during the transition from a 40 ka to a 100 ka world in the mid-Pleistocene. Gases trapped in Antarctic ice are the most direct access available to investigate the composition of the paleo-atmosphere of that age and processes related to climate variability. The International Partnerships in Ice Core Sciences (IPICS) Oldest Ice endeavour aims at obtaining an undisturbed ice-core record older than 1 Ma. In addition to ice cores, time slices of paleo-records, available, for example, in Antarctic blue-ice fields, provide further valuable information, which complements continuous time series based on ice cores. This special issue will assemble contributions dedicated to the preparatory phase of this global effort to obtain ice samples and time series older than 700 000 years. This includes a consideration of glaciogical and geophysical settings which allow the presence of old ice, results from pre-site surveys and modelling studies, aspects of ice-core and other sampling techniques and analyses, and requirements for drilling and core handling.

The reconstruction of ocean history, called palaeoceanography, is a relatively young scientific discipline initiated by the work of Cesare Emiliani and colleagues in the 50s of the last century by studying the stable oxygen and carbon isotopic composition of marine organisms. It had its climax in the 70s and 80s, for example in "The Fate of Fossil Fuel CO₂ in the Oceans", a visionary book edited by Andersen and Malahoff published in 1977. Here, seminal contributions by people like Wally Broecker and Wolfgang Berger document the importance of quantifying the magnitude and rate of climatic change as well as variability in the past to better understand the effect of human action on the climate system leading to ongoing global warming. A broad spectrum of studies have been performed since then, ranging from process and modelling studies as well as laboratory culturing of marine organisms to so-called high-resolution studies in time intervals of rapid climate change during the Cenozoic with a focus on the Pleistocene and Holocene. For the latter studies, sediment cores taken during the DSDP and IODP expeditions are a natural archive for the ocean history of the past 60 million years. Dick Kroon already realized all this as a student and spent his whole life dedicated to this field of science in a passionate way.

For this special issue (SI) we invite contributions from colleagues of Dick who cooperated with him in his numerous projects in teaching and research. Topics should be related to (palaeo)oceanography and cover time intervals from the Holocene to the Cenozoic.

We will add a special appendix to this SI, to which people can contribute personal memories and stories about Dick.

The global vegetation distribution determines the physical properties of the land surface, such as the roughness, albedo or water conductivity, and is a key player in the terrestrial carbon cycle. Hence, the vegetation directly affects the climate on Earth. In turn, the global climate controls the large-scale spatial vegetation distribution. Biogeophysical and biogeochemical interactions between vegetation and climate have contributed to past climate changes and will affect the future. Understanding past vegetation dynamics and their role in the climate system is thus of utmost importance.

The increasing publication of large-scale syntheses of vegetation reconstructions and the steadily growing ability to perform long-term transient and sophisticated past time-slice Earth system model simulations allow for more and more detailed analyses of the large-scale vegetation transitions and their effect on climate. However, previous studies also reveal that new metrics are needed to quantitatively compare the more complex reconstructions and model results.

With this special issue, we would like to bundle reconstructions, vegetation simulations and comparison tools. We invite all papers on the broad theme of past vegetation dynamics and their interaction with climate. This includes (a) vegetation simulations of various time intervals, (b) regional to global data–model or model–model comparison studies, (c) development of data–model comparison tools and techniques, and (d) vegetation–climate dynamics inferred from compilations of regional to global vegetation records. Any other related topic (past land use or past fire dynamics) is also welcome. Data compilation products may also be considered if the compiled data are integrated and used to address specific questions about past vegetation dynamics.

Two closely coordinated groups (one from the USA and the other from Europe) are revisiting the Camp Century sub-ice sediment and the silty ice zone just above it using a wide variety of analytical techniques to make inferences about ice sheet behaviour, palaeo-climate, and palaeo-ecology as well as sediment transport and sourcing. The paper that kicked this off was in Proceedings of the National Academy of Sciences (PNAS) 2 years ago: "A multi-million-year-old record of Greenland vegetation and glacial history preserved in sediment beneath 1.4 km of ice at Camp Century" (Christ et al., 2021).

Talking among the 20+ lead investigators, we decided that the papers coming out of multiple, coordinated investigations of this historic (and still unique) ice core would be very useful to the broader community if they could be gathered into a special issue. Having these papers together would increase their impact and accessibility. Because of the wide variety of investigations being conducted on the core materials, a combined special issue including papers from both The Cryosphere and Climate of the Past will generate the most contributions and the largest readership.

Reference:

Christ, A. J., Bieman, P. R., Schaefer, J. M., Dahl-Jensen, D., Steffensen, J. P, Corbett, L. B., Peteet, D. M., Thomas, E. K., Steig, E. J., Rittenour, T. M., Tison, J.-L., Blard, P.-H., Perdrial, N., Dethier, D. P., Lini, A., Hidy, A. J., Caffee, M. W., and Southon, J.: A multi-million-year-old record of Greenland vegetation and glacial history preserved in sediment beneath 1.4 km of ice at Camp Century, P. Natl. Acad. Sci. USA, 118, e2021442118, https://doi.org/10.1073/pnas.2021442118, 2021.

Volcanic eruptions are one of the major natural factors influencing climate variability at interannual to multidecadal timescales. However, simulating volcanically forced climate variability is a challenging task for climate models and one of the major uncertainties in near-term climate predictions. The Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP) is an endorsed contribution to the sixth phase of the Coupled Model Intercomparison Project. This multi-journal special issue on VolMIP aims at collecting relevant research results obtained within the VolMIP framework, and specifically concerning different aspects of the radiative and dynamical climatic response to volcanic forcing, detailed description of effects of different implementation of volcanic forcing in current climate models, aspects concerning the dynamical and chemical atmospheric response to volcanic aerosols simulated by global aerosol models, and comparison between reconstructed and simulated climate evolution after major eruptions.

Studies of ice extent, volume, and dynamics during former glaciations are important for understanding past climates and evolution of the Earth's surface, and they also provide analogies for present-day and future ice sheets and their subglacial environments. The special issue (SI) "Icy landscapes of the past" brings together contributions from four Copernicus journals (Climate of the Past, The Cryosphere, Earth Surface Dynamics, and Earth System Science Data), reflecting the interdisciplinarity across scientific communities working with former glaciations from the perspectives of palaeoclimatology, glacial geomorphology, Quaternary geology, and numerical modelling, among others. It provides a platform from which field-based reconstructions and model simulations can be compared and contrasted, teasing out complex couplings between the changing cryosphere-induced topographic, freshwater, and sea level forcings and climate states of both warmer and colder epochs of the past. Through this SI, we aim to piece together the growing knowledge about regional responses of different geographic regions to past climate changes to obtain a global picture, thereby fostering emerging collaborations between previously disconnected geoscientific disciplines. We welcome contributions that shed light on ancient and more recent glaciations on Earth and their interaction with other components of the Earth system.

Two closely coordinated groups (one from the USA and the other from Europe) are revisiting the Camp Century sub-ice sediment and the silty ice zone just above it using a wide variety of analytical techniques to make inferences about ice sheet behaviour, palaeo-climate, and palaeo-ecology as well as sediment transport and sourcing. The paper that kicked this off was in Proceedings of the National Academy of Sciences (PNAS) 2 years ago: "A multi-million-year-old record of Greenland vegetation and glacial history preserved in sediment beneath 1.4 km of ice at Camp Century" (Christ et al., 2021).

Talking among the 20+ lead investigators, we decided that the papers coming out of multiple, coordinated investigations of this historic (and still unique) ice core would be very useful to the broader community if they could be gathered into a special issue. Having these papers together would increase their impact and accessibility. Because of the wide variety of investigations being conducted on the core materials, a combined special issue including papers from both The Cryosphere and Climate of the Past will generate the most contributions and the largest readership.

Reference:

Christ, A. J., Bieman, P. R., Schaefer, J. M., Dahl-Jensen, D., Steffensen, J. P, Corbett, L. B., Peteet, D. M., Thomas, E. K., Steig, E. J., Rittenour, T. M., Tison, J.-L., Blard, P.-H., Perdrial, N., Dethier, D. P., Lini, A., Hidy, A. J., Caffee, M. W., and Southon, J.: A multi-million-year-old record of Greenland vegetation and glacial history preserved in sediment beneath 1.4 km of ice at Camp Century, P. Natl. Acad. Sci. USA, 118, e2021442118, https://doi.org/10.1073/pnas.2021442118, 2021.

The reconstruction of ocean history, called palaeoceanography, is a relatively young scientific discipline initiated by the work of Cesare Emiliani and colleagues in the 50s of the last century by studying the stable oxygen and carbon isotopic composition of marine organisms. It had its climax in the 70s and 80s, for example in "The Fate of Fossil Fuel CO₂ in the Oceans", a visionary book edited by Andersen and Malahoff published in 1977. Here, seminal contributions by people like Wally Broecker and Wolfgang Berger document the importance of quantifying the magnitude and rate of climatic change as well as variability in the past to better understand the effect of human action on the climate system leading to ongoing global warming. A broad spectrum of studies have been performed since then, ranging from process and modelling studies as well as laboratory culturing of marine organisms to so-called high-resolution studies in time intervals of rapid climate change during the Cenozoic with a focus on the Pleistocene and Holocene. For the latter studies, sediment cores taken during the DSDP and IODP expeditions are a natural archive for the ocean history of the past 60 million years. Dick Kroon already realized all this as a student and spent his whole life dedicated to this field of science in a passionate way.

For this special issue (SI) we invite contributions from colleagues of Dick who cooperated with him in his numerous projects in teaching and research. Topics should be related to (palaeo)oceanography and cover time intervals from the Holocene to the Cenozoic.

We will add a special appendix to this SI, to which people can contribute personal memories and stories about Dick.

Ice cores provide a wealth of information about past climate and environmental conditions as well as direct records of the composition of the atmosphere on timescales from decades to hundreds of millennia. This comprises deep ice cores from both polar ice sheets and from high-altitude glaciers, with the latter responding most sensitively to human interaction with the Earth system.

In October 2022 the 3rd Open Science Conference of the International Partnerships of Ice Core Sciences (IPICS) takes place in Crans-Montana, Switzerland, providing the opportunity to document the status quo of ice core research including comparative studies on other climate archives and climate models in this joint special issue of Climate of the Past and The Cryosphere: "Ice core science at the three poles".

Potential topics of contributions include the latest results from polar and high-altitude ice cores, integrative science on ice cores, climate models and other climate archives, new proxies, and other ice-core-related technology developments. In particular, we invite ice-core-related contributions on the following themes.

1. Glacial–interglacial dynamics, interglacials, and sea level
2. Holocene and the last 2000-year climate forcings and variability
3. Progress in proxy development and interpretation
4. Ice dynamics, ice sheet instability, and geophysics
5. High-alpine ice cores
6. Ice biology, basal ice, and subglacial lakes
7. Pollution records
8. Advances in drilling engineering and borehole observations
9. Timescales and methods for ice dating
10. Rapid changes and teleconnections
11. Biogeochemical cycles in the Earth system – data and models
12. New ice archives
13. The Oldest Ice challenge and the preservation of climatic signals in the deepest ice.

The global vegetation distribution determines the physical properties of the land surface, such as the roughness, albedo or water conductivity, and is a key player in the terrestrial carbon cycle. Hence, the vegetation directly affects the climate on Earth. In turn, the global climate controls the large-scale spatial vegetation distribution. Biogeophysical and biogeochemical interactions between vegetation and climate have contributed to past climate changes and will affect the future. Understanding past vegetation dynamics and their role in the climate system is thus of utmost importance.

The increasing publication of large-scale syntheses of vegetation reconstructions and the steadily growing ability to perform long-term transient and sophisticated past time-slice Earth system model simulations allow for more and more detailed analyses of the large-scale vegetation transitions and their effect on climate. However, previous studies also reveal that new metrics are needed to quantitatively compare the more complex reconstructions and model results.

With this special issue, we would like to bundle reconstructions, vegetation simulations and comparison tools. We invite all papers on the broad theme of past vegetation dynamics and their interaction with climate. This includes (a) vegetation simulations of various time intervals, (b) regional to global data–model or model–model comparison studies, (c) development of data–model comparison tools and techniques, and (d) vegetation–climate dynamics inferred from compilations of regional to global vegetation records. Any other related topic (past land use or past fire dynamics) is also welcome. Data compilation products may also be considered if the compiled data are integrated and used to address specific questions about past vegetation dynamics.

Volcanic eruptions are one of the major natural factors influencing climate variability at interannual to multidecadal timescales. However, simulating volcanically forced climate variability is a challenging task for climate models and one of the major uncertainties in near-term climate predictions. The Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP) is an endorsed contribution to the sixth phase of the Coupled Model Intercomparison Project. This multi-journal special issue on VolMIP aims at collecting relevant research results obtained within the VolMIP framework, and specifically concerning different aspects of the radiative and dynamical climatic response to volcanic forcing, detailed description of effects of different implementation of volcanic forcing in current climate models, aspects concerning the dynamical and chemical atmospheric response to volcanic aerosols simulated by global aerosol models, and comparison between reconstructed and simulated climate evolution after major eruptions.

The glacial–interglacial cyclicity of the climate system varied in the past, most notably during the transition from a 40 ka to a 100 ka world in the mid-Pleistocene. Gases trapped in Antarctic ice are the most direct access available to investigate the composition of the paleo-atmosphere of that age and processes related to climate variability. The International Partnerships in Ice Core Sciences (IPICS) Oldest Ice endeavour aims at obtaining an undisturbed ice-core record older than 1 Ma. In addition to ice cores, time slices of paleo-records, available, for example, in Antarctic blue-ice fields, provide further valuable information, which complements continuous time series based on ice cores. This special issue will assemble contributions dedicated to the preparatory phase of this global effort to obtain ice samples and time series older than 700 000 years. This includes a consideration of glaciogical and geophysical settings which allow the presence of old ice, results from pre-site surveys and modelling studies, aspects of ice-core and other sampling techniques and analyses, and requirements for drilling and core handling.