This study presents the first evaluation from snowfall observations in Antarctica of the general circulation model LMDz (global), the atmospheric component of the coupled IPSL Climate Model that is part of CMIP6 (IPCC). We also present an evaluation of the new version of the MAR model (regional), considered as a reference in terms of polar climate modelling. Both models show satisfying results for the modelling of precipitation in Antarctica.

Evaluation of the vertical precipitation rate profiles of CloudSat radar by comparison with two surface-based micro-rain radars (MRR) located at two antarctic stations gives a near-perfect correlation between both datasets, even though climatic and geographic conditions are different for the stations. A better understanding and reassessment of CloudSat uncertainties ranging from −13 % up to +22 % confirms the robustness of the CloudSat retrievals of snowfall over Antarctica.

Precipitation is the main input in the surface mass balance of the Antarctic ice sheet, but it is still poorly understood due to a lack of observations in this region. We analyzed the vertical structure of the precipitation using multiyear observation of vertically pointing micro rain radars (MRRs) at two stations located in East Antarctica. The use of MRRs showed the potential to study the effect of climatology and hydrometeor microphysics on the vertical structure of Antarctic precipitation.

Oceanic surface conditions coming from coupled ocean–atmosphere global climate models bear considerable biases over the historical climate. We review and present new methods for bias correcting sea surface temperatures and sea-ice concentration coming from such models in order to use them as boundary conditions for atmospheric-only GCMs. For sea ice, we propose a new analogue method which allows us to reproduce more physically consistent future bias-corrected sea-ice concentration maps.

Antarctica suffers from a severe shortage of in situ observations of precipitation. The APRES3 program contributes to improving observation from both the surface and from space. A field campaign with various instruments was deployed at the coast of Adélie Land, with an intensive observing period in austral summer 2015–16, then continuous radar monitoring through 2016 and beyond. This paper provides a compact presentation of the APRES3 dataset, which is now made open to the scientific community.

Ice core isotopic records rely on the knowledge of the processes involved in the archival processes of the snow. In the East Antarctic Plateau, post-deposition processes strongly affect the signal found in the surface and buried snow compared to the initial climatic signal. We evaluate the different contributions to the surface snow isotopic composition between the precipitation and the exchanges with the atmosphere and the variability of the isotopic signal found in profiles from snow pits.

To improve the simulation of vegetation–climate feedbacks at high latitudes, three new circumpolar vegetation types were added in the ORCHIDEE land surface model: bryophytes (mosses) and lichens, Arctic shrubs, and Arctic grasses. This article is an introduction to the modification of vegetation distribution and physical behaviour, implying for example lower productivity, roughness, and higher winter albedo or freshwater discharge in the Arctic Ocean.

Earth system models (ESMs) are our main tools for understanding future climate. The Arctic is important for the future carbon cycle, particularly due to the large carbon stocks in permafrost. We evaluated the performance of the land component of three major ESMs at Arctic tundra sites, focusing on the fluxes and stocks of carbon. We show that the next steps for model improvement are to better represent vegetation dynamics, to include mosses and to improve below-ground carbon cycle processes.

We present medium and long-term measurements of precipitation in a coastal region of Antarctica. These measurements are among the first of their kind on the Antarctic continent and combine remote sensing with in situ observations. The benefits of this synergy are demonstrated and the lessons learned from this measurements, which are still ongoing, are very important for the creation of similar observatories elsewhere on the continent.

Natural atmospheric supersaturation is a norm rather than an exception at the surface of Dome C on the Antarctic Plateau. This is reported by hygrometers adapted to perform in extreme cold environments and avoid release of excess moisture before it is measured. One year of observation shows that atmospheric models with cold microphysics parameterizations designed for high altitude cirrus reproduce frequently but fail with the detailed statistics of supersaturation at the surface of Dome C.

Climatic conditions in Concordia are very cold (−55 °C in average) and very dry, imposing difficult conditions to measure the water vapour isotopic composition. New developments in infrared spectroscopy enable now the measurement of isotopic composition in water vapour traces (down to 20 ppmv). Here we present the results results of a first campaign of measurement of isotopic composition of water vapour in Concordia, the site where the 800 000 years long ice core was drilled.

Regional climate model MAR was run for the region of Dome C located on the East Antarctic plateau, during summer 2011–2012, with a high vertical resolution in the lower troposphere. MAR is generally in very good agreement with the observations and provides sufficiently reliable information about surface turbulent fluxes and vertical profiles of vertical diffusion coefficients when discussing the representativeness of chemical measurements made nearby the ground surface at Dome C.

This is the first time that a low-level jet observed above the East Antarctic Plateau is simulated by a regional climate model. This paper illustrates in a 3-D simulation the respective influences of the large-scale pressure gradient force and turbulence on the onset of the low-level jet. As atmospheric turbulence plays a key role in explaining the behaviour of chemical tracers during the OPALE campaign, this paper also increases our confidence in using the outputs of the model for this purpose.