French Polar Institute Literature Database -- Query Results

Winton V.H.L., Ming A., Caillon N., Hauge L. Jones A.E., Savarino J., Yang X., Frey M.M. (2020). Deposition, recycling, and archival of nitrate stable isotopes between the air–snow interface: comparison between Dronning Maud Land and Dome C, Antarctica (Vol. 20). Bachelor's thesis, , . Abstract: The nitrogen stable isotopic composition in nitrate (δ15N-NO−3) measured in ice cores from low-snow-accumulation regions in East Antarctica has the potential to provide constraints on past ultraviolet (UV) radiation and thereby total column ozone (TCO) due to the sensitivity of nitrate (NO−3) photolysis to UV radiation. However, understanding the transfer of reactive nitrogen at the air–snow interface in polar regions is paramount for the interpretation of ice core records of δ15N-NO−3 and NO−3 mass concentrations. As NO−3 undergoes a number of post-depositional processes before it is archived in ice cores, site-specific observations of δ15N-NO−3 and air–snow transfer modelling are necessary to understand and quantify the complex photochemical processes at play. As part of the Isotopic Constraints on Past Ozone Layer Thickness in Polar Ice (ISOL-ICE) project, we report new measurements of NO−3 mass concentration and δ15N-NO−3 in the atmosphere, skin layer (operationally defined as the top 5 mm of the snowpack), and snow pit depth profiles at Kohnen Station, Dronning Maud Land (DML), Antarctica. We compare the results to previous studies and new data, presented here, from Dome C on the East Antarctic Plateau. Additionally, we apply the conceptual 1D model of TRansfer of Atmospheric Nitrate Stable Isotopes To the Snow (TRANSITS) to assess the impact of NO−3 recycling on δ15N-NO−3 and NO−3 mass concentrations archived in snow and firn. We find clear evidence of NO−3 photolysis at DML and confirmation of previous theoretical, field, and laboratory studies that UV photolysis is driving NO−3 recycling and redistribution at DML. Firstly, strong denitrification of the snowpack is observed through the δ15N-NO−3 signature, which evolves from the enriched snowpack (−3 ‰ to 100 ‰), to the skin layer (−20 ‰ to 3 ‰), to the depleted atmosphere (−50 ‰ to −20 ‰), corresponding to mass loss of NO−3 from the snowpack. Based on the TRANSITS model, we find that NO−3 is recycled two times, on average, before it is archived in the snowpack below 15 cm and within 0.75 years (i.e. below the photic zone). Mean annual archived δ15N-NO−3 and NO−3 mass concentration values are 50 ‰ and 60 ng g−1, respectively, at the DML site. We report an e-folding depth (light attenuation) of 2–5 cm for the DML site, which is considerably lower than Dome C. A reduced photolytic loss of NO−3 at DML results in less enrichment of δ15N-NO−3 than at Dome C mainly due to the shallower e-folding depth but also due to the higher snow accumulation rate based on TRANSITS-modelled sensitivities. Even at a relatively low snow accumulation rate of 6 cm yr−1 (water equivalent; w.e.), the snow accumulation rate at DML is great enough to preserve the seasonal cycle of NO−3 mass concentration and δ15N-NO−3, in contrast to Dome C where the depth profiles are smoothed due to longer exposure of surface snow layers to incoming UV radiation before burial. TRANSITS sensitivity analysis of δ15N-NO−3 at DML highlights that the dominant factors controlling the archived δ15N-NO−3 signature are the e-folding depth and snow accumulation rate, with a smaller role from changes in the snowfall timing and TCO. Mean TRANSITS model sensitivities of archived δ15N-NO−3 at the DML site are 100 ‰ for an e-folding depth change of 8 cm, 110 ‰ for an annual snow accumulation rate change of 8.5 cm yr−1 w.e., 10 ‰ for a change in the dominant snow deposition season between winter and summer, and 10 ‰ for a TCO change of 100 DU (Dobson units). Here we set the framework for the interpretation of a 1000-year ice core record of δ15N-NO−3 from DML. Ice core δ15N-NO−3 records at DML will be less sensitive to changes in UV than at Dome C; however the higher snow accumulation rate and more accurate dating at DML allows for higher-resolution δ15N-NO−3 records. Programme: 1177 http://publi.ipev.fr/polar_references/show.php?record=7855
Weisen Shen, Douglas A. Wiens, Sridhar Anandakrishnan, Richard C. Aster, Peter Gerstoft, Peter D. Bromirski, Samantha E. Hansen, Ian W. D. Dalziel, David S. Heeszel, Audrey D. Huerta, Andrew A. Nyblade, Ralph Stephen, Terry J. Wilson, J. Paul Winberry. (2018). The Crust and Upper Mantle Structure of Central and West Antarctica From Bayesian Inversion of Rayleigh Wave and Receiver Functions (Vol. 123). Abstract: We construct a new seismic model for central and West Antarctica by jointly inverting Rayleigh wave phase and group velocities along with P wave receiver functions. Ambient noise tomography exploiting data from more than 200 seismic stations deployed over the past 18 years is used to construct Rayleigh wave phase and group velocity dispersion maps. Comparison between the ambient noise phase velocity maps with those constructed using teleseismic earthquakes confirms the accuracy of both results. These maps, together with P receiver function waveforms, are used to construct a new 3-D shear velocity (Vs) model for the crust and uppermost mantle using a Bayesian Monte Carlo algorithm. The new 3-D seismic model shows the dichotomy of the tectonically active West Antarctica (WANT) and the stable and ancient East Antarctica (EANT). In WANT, the model exhibits a slow uppermost mantle along the Transantarctic Mountains (TAMs) front, interpreted as the thermal effect from Cenozoic rifting. Beneath the southern TAMs, the slow uppermost mantle extends horizontally beneath the traditionally recognized EANT, hypothesized to be associated with lithospheric delamination. Thin crust and lithosphere observed along the Amundsen Sea coast and extending into the interior suggest involvement of these areas in Cenozoic rifting. EANT, with its relatively thick and cold crust and lithosphere marked by high Vs, displays a slower Vs anomaly beneath the Gamburtsev Subglacial Mountains in the uppermost mantle, which we hypothesize may be the signature of a compositionally anomalous body, perhaps remnant from a continental collision. Keywords: ambient noise tomography Antarctica crust and uppermost mantle Gamburtsev Mountains seismology Transantarctic Mountains Programme: 133 http://publi.ipev.fr/polar_references/show.php?record=7878
Elena Dobrică, Ryan C. Ogliore, Cécile Engrand, Kazuhide Nagashima, Adrian J. Brearley. (2019). Mineralogy and oxygen isotope systematics of magnetite grains and a magnetite-dolomite assemblage in hydrated fine-grained Antarctic micrometeorites (Vol. 54). Abstract: We report the mineralogy and texture of magnetite grains, a magnetite-dolomite assemblage, and the adjacent mineral phases in five hydrated fine-grained Antarctic micrometeorites (H-FgMMs). Additionally, we measured the oxygen isotopic composition of magnetite grains and a magnetite-dolomite assemblage in these samples. Our mineralogical study shows that the secondary phases identified in H-FgMMs have similar textures and chemical compositions to those described previously in other primitive solar system materials, such as carbonaceous chondrites. However, the oxygen isotopic compositions of magnetite in H-FgMMs span a range of ∆17O values from +1.3‰ to +4.2‰, which is intermediate between magnetites measured in carbonaceous and ordinary chondrites (CCs and OCs). The δ18O values of magnetites in one H-FgMM have a 27‰ mass-dependent spread in a single 100 × 200 μm particle, indicating that there was a localized control of the fluid composition, probably due to a low water-to-rock mass ratio. The ∆17O values of magnetite indicate that H-FgMMs sampled a different aqueous fluid than ordinary and carbonaceous chondrites, implying that the source of H-FgMMs is probably distinct from the asteroidal source of CCs and OCs. Additionally, we analyzed the oxygen isotopic composition of a magnetite-dolomite assemblage in one of the H-FgMMs (sample 03-36-46) to investigate the temperature at which these minerals coprecipitated. We have used the oxygen isotope fractionation between the coexisting magnetite and dolomite to infer a precipitation temperature between 160 and 280 °C for this sample. This alteration temperature is 100–200 °C warmer than that determined from a calcite-magnetite assemblage from the CR2 chondrite Al Rais, but similar to the estimated temperature of aqueous alteration for unequilibrated OCs, CIs, and CMs. This suggests that the sample 03-36-46 could come from a parent body that was large enough to attain temperatures as high as the OCs, CIs, and CMs, which implies an asteroidal origin for this particular H-FgMM. Programme: 1120 http://publi.ipev.fr/polar_references/show.php?record=7898
Chengsheng Zhu, Maximilian Miller, Nicholas Lusskin, Benoît Bergk Pinto, Lorrie Maccario, Max Häggblom, Timothy Vogel, Catherine Larose, Yana Bromberg. (2020). Snow microbiome functional analyses reveal novel aspects of microbial metabolism of complex organic compounds (Vol. 9). Abstract: Microbes active in extreme cold are not as well explored as those of other extreme environments. Studies have revealed a substantial microbial diversity and identified cold-specific microbiome molecular functions. We analyzed the metagenomes and metatranscriptomes of 20 snow samples collected in early and late spring in Svalbard, Norway using mi-faser, our read-based computational microbiome function annotation tool. Our results reveal a more diverse microbiome functional capacity and activity in the early- vs. late-spring samples. We also find that functional dissimilarity between the same-sample metagenomes and metatranscriptomes is significantly higher in early than late spring samples. These findings suggest that early spring samples may contain a larger fraction of DNA of dormant (or dead) organisms, while late spring samples reflect a new, metabolically active community. We further show that the abundance of sequencing reads mapping to the fatty acid synthesis-related microbial pathways in late spring metagenomes and metatranscriptomes is significantly correlated with the organic acid levels measured in these samples. Similarly, the organic acid levels correlate with the pathway read abundances of geraniol degradation and inversely correlate with those of styrene degradation, suggesting a possible nutrient change. Our study thus highlights the activity of microbial degradation pathways of complex organic compounds previously unreported at low temperatures. Keywords: metagenome metatranscriptome mi-faser snow microbiome Programme: 1192 http://publi.ipev.fr/polar_references/show.php?record=7964
O. I. Berngardt, J.-P. St- Maurice, J. M. Ruohoniemi, A. Marchaudon. (2022). Seasonal and Diurnal Dynamics of Radio Noise for 8–20 MHz Poleward-Oriented Mid-Latitude Radars (Vol. 57). Abstract: Based on ray tracing in a smooth ionosphere described by the IRI-2012 model we have inferred the seasonal-diurnal dynamics of radio noise observed by four mid-latitude high-frequency (HF) radars. In the calculations, noise is assumed to be homogeneous and stationary, but the main contribution comes from the radar skip zone boundary due to focusing radiowaves effect. Noise absorption along the ray path is simulated from the IRI-2012 electron density, and from the molecular nitrogen density and electron temperatures obtained from the NRLMSISE-00 model. Earth magnetic field is not taken into account both in the absorption and ray-tracing calculations due to insufficient accuracy of the ionospheric model. The model results are compared with experimental radar data, and good agreement between the two is demonstrated. It is shown that experimentally observed seasonal and diurnal dynamics of the noise correlates well with model predictions. We demonstrated saturation effect at low noise levels. The model makes it possible to estimate the amount of absorption in D- and E-layers using noise observations at SuperDARN and SuperDARN-like poleward-oriented radars, especially at mid-latitudes. This is important for the retrieval of long term variations in the electron density in the lower ionosphere, by using wide coverage provided by these radars' network. The model also makes it feasible to interpret vertical absorption by experimental noise observations, thereby significantly expanding the capability of HF radars to monitor the lower ionosphere, and to provide data for joint analysis with other data, obtained by these radars at E- and F-layer heights. Keywords: HF radars ionospheric absorption noise quiet-day curve radiowave propagation Programme: 312 http://publi.ipev.fr/polar_references/show.php?record=8075
Baptiste Le Bourg, Thomas Saucède, Anouk Charpentier, Gilles Lepoint, Loïc N. Michel. (2022). What is the menu today in a subantarctic kelp food web from the Kerguelen Islands? Phytodetritus, phytoplankton and phytobenthos; not living kelp (Vol. 169). Abstract: Kelp forests dominated by Macrocystis pyrifera are widely distributed in coastal waters from boreal, temperate and subantarctic regions. This widespread distribution may result in regional differences in food web structure and functioning. In temperate northern regions, where most studies on kelp forest benthic food webs have been conducted, kelp grazing is a well-documented phenomenon and can lead to the overgrazing of M. pyrifera by sea urchins when their predators (e.g., sea otters) are absent. In contrast, little is known about their counterparts in subantarctic areas. The present study aimed to reconstruct the benthic food web of a kelp forest dominated by M. pyrifera in a subantarctic environment using stable isotope analysis. Stable carbon (δ13C), nitrogen (δ15N) and sulfur (δ34S) isotope ratios were measured from food sources (macrophytobenthos, suspended particulate organic matter SPOM, and sediment) and consumers (sponges, bivalves, gastropods, sedentary and mobile polychaetes, arthropods and echinoderms) which were sampled in a kelp forest of the Kerguelen archipelago. Mixing models highlighted two interconnected trophic pathways which were either supported by SPOM and resuspended macrophytobenthos detritus (bentho-pelagic), or by live micro/macrophytobenthos (phytobenthos-based). No major prey were highlighted for several consumers, indicating the existence of potential supplementary trophic pathways. No consumer relying primarily on living M. pyrifera was highlighted by the mixing models. The investigated kelp forest is hence a complex ecosystem supporting multiple trophic pathways, and direct consumption of M. pyrifera is limited. Nonetheless, M. pyrifera and other macrophytobenthos species may constitute a pool of detritus supporting several trophic pathways. Keywords: Benthic communities Food web Kelp forests Mixing models Stable isotopes Programme: 1044 http://publi.ipev.fr/polar_references/show.php?record=8474
Guillaumot Charlène, Danis Bruno, Saucède Thomas. (2020). Selecting environmental descriptors is critical for modelling the distribution of Antarctic benthic species (Vol. 43). Bachelor's thesis, , . Abstract: Species distribution models (SDMs) are increasingly used in ecological and biogeographic studies by Antarctic biologists, including for conservation and management purposes. During the modelling process, model calibration is a critical step to ensure model reliability and robustness, especially in the case of SDMs, for which the number of selected environmental descriptors and their collinearity is a recurring issue. Boosted regression trees (BRT) was previously considered as one of the best modelling approach to correct for this type of bias. In the present study, we test the performance of BRT in modelling the distribution of Southern Ocean species using different numbers of environmental descriptors, either collinear or not. Models are generated for six sea star species with contrasting ecological niches and wide distribution ranges over the entire Southern Ocean. For the six studied species, overall modelling performance is not affected by the number of environmental descriptors used to generate models, BRT using the most informative descriptors and minimizing model overfitting. However, removing collinear descriptors also helps reduce model overfitting. Our results confirm that BRTs may perform well and are relevant to deal with complex and redundant environmental information for Antarctic biodiversity distribution studies. Selecting a limited number of non-collinear descriptors before modelling may generate simpler models and facilitate their interpretation. The modelled distributions do not differ noticeably between the different species despite contrasting species ecological niches. This unexpected result stresses important limitations in using SDMs for broad scale spatial studies, based on limited, spatially aggregated data, and low-resolution descriptors. Programme: 1044,1124 http://publi.ipev.fr/polar_references/show.php?record=8184
Deborah Verfaillie, Vincent Favier, Hubert Gallée, Xavier Fettweis, Cécile Agosta, Vincent Jomelli. (2019). Regional modeling of surface mass balance on the Cook Ice Cap, Kerguelen Islands (49∘S, 69∘E) (Vol. 53). Abstract: We assess the ability of the regional circulation model MAR to represent the recent negative surface mass balance (SMB) observed over the Kerguelen Islands (49∘S, 69∘E) and evaluate the uncertainties in SMB projections until the end of the century. The MAR model forced by ERA-Interim reanalysis shows a good agreement with meteorological observations at Kerguelen, particularly after slight adjustment of the forcing fields (+ 10% humidity, +0.8∘C, all year round) to improve precipitation occurrence and intensity. The modeled SMB and surface energy balance (SEB) are also successfully evaluated with observations, and spatial distributions are explained as being largely driven by the elevation gradient and by the strong west to east foehn effect occurring on the ice cap. We select five general circulation models (GCMs) from the Coupled Model Intercomparison Project phase 5 (CMIP5) by evaluating their ability to represent temperature and humidity in the southern mid-latitudes over 1980–1999 with respect to ERA-Interim and use them to force the MAR model. These simulations fail to replicate SMB observations even when outputs from the best CMIP5 model (ACCESS1-3) are used as forcing because all GCMs fail in accurately reproducing the circulation changes observed at Kerguelen since the mid-1970s. Global models chosen to represent extreme values of SMB drivers also fail in producing extreme values of SMB, suggesting that more rigorous modeling of present and future circulation changes with GCMs is still needed to accurately assess future changes of the cryosphere in this area. Programme: 1048 http://publi.ipev.fr/polar_references/show.php?record=8185
Francesco Enrichi, Dorthe Dahl-Jensen, Jørgen Peder Steffensen, Carlo Barbante. (2021). Theoretical and Experimental Analysis for Cleaning Ice Cores from EstisolTM 140 Drill Liquid (Vol. 11). Abstract: To reconstruct climate history of the past 1.5 Million years, the project: Beyond EPICA Oldest Ice (BEOI) will drill about 2700 m of ice core in East Antarctica (2021–2025). As drilling fluid, an aliphatic ester fluid, EstisolTM 140, will be used. Newly drilled ice cores will be retrieved from the drill soaked in fluid, and this fluid should be removed from the cores. Most of it will be vacuum-cleaned off in a Fluid Extraction Device and wiped off with paper towels. Based on our experiences in Greenland deep ice coring, most of the residual fluid can be removed by storing the cores openly on shelves in a ventilated room. After a week of “drying”, the cores have a dry feel, handling them do not give “wet” gloves and they can easily be marked with lead pencils. This paper presents a theoretical investigation and some simple testing on the “drying” process. The rates of sublimation of ice and evaporation of fluid have been calculated at different temperatures. The calculations show that sublimation of the ice core should not occur, and that evaporation of fluid should be almost negligible. Our test results support these calculations, but also revealed significant fluid run-off and dripping, resulting in the removal of most of the fluid in a couple of days, independent of temperature and ventilation conditions. Finally, we discuss crucial factors that ensure optimal long-term ice core preservation in storage, such as temperature stability, defrosting cycles of freezers and open core storage versus storage of cores in insulated crates. Keywords: Beyond EPICA drilling Estisol ice cores Programme: 1202 http://publi.ipev.fr/polar_references/show.php?record=8247
Jonas J. Lembrechts, Johan van den Hoogen, Juha Aalto, Michael B. Ashcroft, Pieter De Frenne, Julia Kemppinen, Martin Kopecký, Miska Luoto, Ilya M. D. Maclean, Thomas W. Crowther, Joseph J. Bailey, Stef Haesen, David H. Klinges, Pekka Niittynen, Brett R. Scheffers, Koenraad Van Meerbeek, Peter Aartsma, Otar Abdalaze, Mehdi Abedi, Rien Aerts, Negar Ahmadian, Antje Ahrends, Juha M. Alatalo, Jake M. Alexander, Camille Nina Allonsius, Jan Altman, Christof Ammann, Christian Andres, Christopher Andrews, Jonas Ardö, Nicola Arriga, Alberto Arzac, Valeria Aschero, Rafael L. Assis, Jakob Johann Assmann, Maaike Y. Bader, Khadijeh Bahalkeh, Peter Barančok, Isabel C. Barrio, Agustina Barros, Matti Barthel, Edmund W. Basham, Marijn Bauters, Manuele Bazzichetto, Luca Belelli Marchesini, Michael C. Bell, Juan C. Benavides, José Luis Benito Alonso, Bernd J. Berauer, Jarle W. Bjerke, Robert G. Björk, Mats P. Björkman, Katrin Björnsdóttir, Benjamin Blonder, Pascal Boeckx, Julia Boike, Stef Bokhorst, Bárbara N. S. Brum, Josef Brůna, Nina Buchmann, Pauline Buysse, José Luís Camargo, Otávio C. Campoe, Onur Candan, Rafaella Canessa, Nicoletta Cannone, Michele Carbognani, Jofre Carnicer, Angélica Casanova-Katny, Simone Cesarz, Bogdan Chojnicki, Philippe Choler, Steven L. Chown, Edgar F. Cifuentes, Marek Čiliak, Tamara Contador, Peter Convey, Elisabeth J. Cooper, Edoardo Cremonese, Salvatore R. Curasi, Robin Curtis, Maurizio Cutini, C. Johan Dahlberg, Gergana N. Daskalova, Miguel Angel de Pablo, Stefano Della Chiesa, Jürgen Dengler, Bart Deronde, Patrice Descombes, Valter Di Cecco, Michele Di Musciano, Jan Dick, Romina D. Dimarco, Jiri Dolezal, Ellen Dorrepaal, Jiří Dušek, Nico Eisenhauer, Lars Eklundh, Todd E. Erickson, Brigitta Erschbamer, Werner Eugster, Robert M. Ewers, Dan A. Exton, Nicolas Fanin, Fatih Fazlioglu, Iris Feigenwinter, Giuseppe Fenu, Olga Ferlian, M. Rosa Fernández Calzado, Eduardo Fernández-Pascual, Manfred Finckh, Rebecca Finger Higgens, T'ai G. W. Forte, Erika C. Freeman, Esther R. Frei, Eduardo Fuentes-Lillo, Rafael A. García, María B. García, Charly Géron, Mana Gharun, Dany Ghosn, Khatuna Gigauri, Anne Gobin, Ignacio Goded, Mathias Goeckede, Felix Gottschall, Keith Goulding, Sanne Govaert, Bente Jessen Graae, Sarah Greenwood, Caroline Greiser, Achim Grelle, Benoit Guénard, Mauro Guglielmin, Joannès Guillemot, Peter Haase, Sylvia Haider, Aud H. Halbritter, Maroof Hamid, Albin Hammerle, Arndt Hampe, Siri V. Haugum, Lucia Hederová, Bernard Heinesch, Carole Helfter, Daniel Hepenstrick, Maximiliane Herberich, Mathias Herbst, Luise Hermanutz, David S. Hik, Raúl Hoffrén, Jürgen Homeier, Lukas Hörtnagl, Toke T. Høye, Filip Hrbacek, Kristoffer Hylander, Hiroki Iwata, Marcin Antoni Jackowicz-Korczynski, Hervé Jactel, Järvi Järveoja, Szymon Jastrzębowski, Anke Jentsch, Juan J. Jiménez, Ingibjörg S. Jónsdóttir, Tommaso Jucker, Alistair S. Jump, Radoslaw Juszczak, Róbert Kanka, Vít Kašpar, George Kazakis, Julia Kelly, Anzar A. Khuroo, Leif Klemedtsson, Marcin Klisz, Natascha Kljun, Alexander Knohl, Johannes Kobler, Jozef Kollár, Martyna M. Kotowska, Bence Kovács, Juergen Kreyling, Andrea Lamprecht, Simone I. Lang, Christian Larson, Keith Larson, Kamil Laska, Guerric le Maire, Rachel I. Leihy, Luc Lens, Bengt Liljebladh, Annalea Lohila, Juan Lorite, Benjamin Loubet, Joshua Lynn, Martin Macek, Roy Mackenzie, Enzo Magliulo, Regine Maier, Francesco Malfasi, František Máliš, Matěj Man, Giovanni Manca, Antonio Manco, Tanguy Manise, Paraskevi Manolaki, Felipe Marciniak, Radim Matula, Ana Clara Mazzolari, Sergiy Medinets, Volodymyr Medinets, Camille Meeussen, Sonia Merinero, Rita de Cássia Guimarães Mesquita, Katrin Meusburger, Filip J. R. Meysman, Sean T. Michaletz, Ann Milbau, Dmitry Moiseev, Pavel Moiseev, Andrea Mondoni, Ruth Monfries, Leonardo Montagnani, Mikel Moriana-Armendariz, Umberto Morra di Cella, Martin Mörsdorf, Jonathan R. Mosedale, Lena Muffler, Miriam Muñoz-Rojas, Jonathan A. Myers, Isla H. Myers-Smith, Laszlo Nagy, Marianna Nardino, Ilona Naujokaitis-Lewis, Emily Newling, Lena Nicklas, Georg Niedrist, Armin Niessner, Mats B. Nilsson, Signe Normand, Marcelo D. Nosetto, Yann Nouvellon, Martin A. Nuñez, Romà Ogaya, Jérôme Ogée, Joseph Okello, Janusz Olejnik, Jørgen Eivind Olesen, Øystein H. Opedal, Simone Orsenigo, Andrej Palaj, Timo Pampuch, Alexey V. Panov, Meelis Pärtel, Ada Pastor, Aníbal Pauchard, Harald Pauli, Marian Pavelka, William D. Pearse, Matthias Peichl, Loïc Pellissier, Rachel M. Penczykowski, Josep Penuelas, Matteo Petit Bon, Alessandro Petraglia, Shyam S. Phartyal, Gareth K. Phoenix, Casimiro Pio, Andrea Pitacco, Camille Pitteloud, Roman Plichta, Francesco Porro, Miguel Portillo-Estrada, Jérôme Poulenard, Rafael Poyatos, Anatoly S. Prokushkin, Radoslaw Puchalka, Mihai Pușcaș, Dajana Radujković, Krystal Randall, Amanda Ratier Backes, Sabine Remmele, Wolfram Remmers, David Renault, Anita C. Risch, Christian Rixen, Sharon A. Robinson, Bjorn J. M. Robroek, Adrian V. Rocha, Christian Rossi, Graziano Rossi, Olivier Roupsard, Alexey V. Rubtsov, Patrick Saccone, Clotilde Sagot, Jhonatan Sallo Bravo, Cinthya C. Santos, Judith M. Sarneel, Tobias Scharnweber, Jonas Schmeddes, Marius Schmidt, Thomas Scholten, Max Schuchardt, Naomi Schwartz, Tony Scott, Julia Seeber, Ana Cristina Segalin de Andrade, Tim Seipel, Philipp Semenchuk, Rebecca A. Senior, Josep M. Serra-Diaz, Piotr Sewerniak, Ankit Shekhar, Nikita V. Sidenko, Lukas Siebicke, Laura Siegwart Collier, Elizabeth Simpson, David P. Siqueira, Zuzana Sitková, Johan Six, Marko Smiljanic, Stuart W. Smith, Sarah Smith-Tripp, Ben Somers, Mia Vedel Sørensen, José João L. L. Souza, Bartolomeu Israel Souza, Arildo Souza Dias, Marko J. Spasojevic, James D. M. Speed, Fabien Spicher, Angela Stanisci, Klaus Steinbauer, Rainer Steinbrecher, Michael Steinwandter, Michael Stemkovski, Jörg G. Stephan, Christian Stiegler, Stefan Stoll, Martin Svátek, Miroslav Svoboda, Torbern Tagesson, Andrew J. Tanentzap, Franziska Tanneberger, Jean-Paul Theurillat, Haydn J. D. Thomas, Andrew D. Thomas, Katja Tielbörger, Marcello Tomaselli, Urs Albert Treier, Mario Trouillier, Pavel Dan Turtureanu, Rosamond Tutton, Vilna A. Tyystjärvi, Masahito Ueyama, Karol Ujházy, Mariana Ujházyová, Domas Uogintas, Anastasiya V. Urban, Josef Urban, Marek Urbaniak, Tudor-Mihai Ursu, Francesco Primo Vaccari, Stijn Van de Vondel, Liesbeth van den Brink, Maarten Van Geel, Vigdis Vandvik, Pieter Vangansbeke, Andrej Varlagin, G. F. Veen, Elmar Veenendaal, Susanna E. Venn, Hans Verbeeck, Erik Verbrugggen, Frank G. A. Verheijen, Luis Villar, Luca Vitale, Pascal Vittoz, Maria Vives-Ingla, Jonathan von Oppen, Josefine Walz, Runxi Wang, Yifeng Wang, Robert G. Way, Ronja E. M. Wedegärtner, Robert Weigel, Jan Wild, Matthew Wilkinson, Martin Wilmking, Lisa Wingate, Manuela Winkler, Sonja Wipf, Georg Wohlfahrt, Georgios Xenakis, Yan Yang, Zicheng Yu, Kailiang Yu, Florian Zellweger, Jian Zhang, Zhaochen Zhang, Peng Zhao, Klaudia Ziemblińska, Reiner Zimmermann, Shengwei Zong, Viacheslav I. Zyryanov, Ivan Nijs, Jonathan Lenoir. (2022). Global maps of soil temperature (Vol. 28). Abstract: Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-km2 resolution for 0–5 and 5–15 cm soil depth. These maps were created by calculating the difference (i.e. offset) between in situ soil temperature measurements, based on time series from over 1200 1-km2 pixels (summarized from 8519 unique temperature sensors) across all the world's major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10°C (mean = 3.0 ± 2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 ± 2.3°C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (−0.7 ± 2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications. Keywords: bioclimatic variables global maps microclimate near-surface temperatures soil temperature soil-dwelling organisms temperature offset weather stations Programme: 136 http://publi.ipev.fr/polar_references/show.php?record=8368

Winton V.H.L., Ming A., Caillon N., Hauge L. Jones A.E., Savarino J., Yang X., Frey M.M. (2020). Deposition, recycling, and archival of nitrate stable isotopes between the air–snow interface: comparison between Dronning Maud Land and Dome C, Antarctica (Vol. 20). Bachelor's thesis, , .

Abstract: The nitrogen stable isotopic composition in nitrate (δ15N-NO−3) measured in ice cores from low-snow-accumulation regions in East Antarctica has the potential to provide constraints on past ultraviolet (UV) radiation and thereby total column ozone (TCO) due to the sensitivity of nitrate (NO−3) photolysis to UV radiation. However, understanding the transfer of reactive nitrogen at the air–snow interface in polar regions is paramount for the interpretation of ice core records of δ15N-NO−3 and NO−3 mass concentrations. As NO−3 undergoes a number of post-depositional processes before it is archived in ice cores, site-specific observations of δ15N-NO−3 and air–snow transfer modelling are necessary to understand and quantify the complex photochemical processes at play. As part of the Isotopic Constraints on Past Ozone Layer Thickness in Polar Ice (ISOL-ICE) project, we report new measurements of NO−3 mass concentration and δ15N-NO−3 in the atmosphere, skin layer (operationally defined as the top 5 mm of the snowpack), and snow pit depth profiles at Kohnen Station, Dronning Maud Land (DML), Antarctica. We compare the results to previous studies and new data, presented here, from Dome C on the East Antarctic Plateau. Additionally, we apply the conceptual 1D model of TRansfer of Atmospheric Nitrate Stable Isotopes To the Snow (TRANSITS) to assess the impact of NO−3 recycling on δ15N-NO−3 and NO−3 mass concentrations archived in snow and firn. We find clear evidence of NO−3 photolysis at DML and confirmation of previous theoretical, field, and laboratory studies that UV photolysis is driving NO−3 recycling and redistribution at DML. Firstly, strong denitrification of the snowpack is observed through the δ15N-NO−3 signature, which evolves from the enriched snowpack (−3 ‰ to 100 ‰), to the skin layer (−20 ‰ to 3 ‰), to the depleted atmosphere (−50 ‰ to −20 ‰), corresponding to mass loss of NO−3 from the snowpack. Based on the TRANSITS model, we find that NO−3 is recycled two times, on average, before it is archived in the snowpack below 15 cm and within 0.75 years (i.e. below the photic zone). Mean annual archived δ15N-NO−3 and NO−3 mass concentration values are 50 ‰ and 60 ng g−1, respectively, at the DML site. We report an e-folding depth (light attenuation) of 2–5 cm for the DML site, which is considerably lower than Dome C. A reduced photolytic loss of NO−3 at DML results in less enrichment of δ15N-NO−3 than at Dome C mainly due to the shallower e-folding depth but also due to the higher snow accumulation rate based on TRANSITS-modelled sensitivities. Even at a relatively low snow accumulation rate of 6 cm yr−1 (water equivalent; w.e.), the snow accumulation rate at DML is great enough to preserve the seasonal cycle of NO−3 mass concentration and δ15N-NO−3, in contrast to Dome C where the depth profiles are smoothed due to longer exposure of surface snow layers to incoming UV radiation before burial. TRANSITS sensitivity analysis of δ15N-NO−3 at DML highlights that the dominant factors controlling the archived δ15N-NO−3 signature are the e-folding depth and snow accumulation rate, with a smaller role from changes in the snowfall timing and TCO. Mean TRANSITS model sensitivities of archived δ15N-NO−3 at the DML site are 100 ‰ for an e-folding depth change of 8 cm, 110 ‰ for an annual snow accumulation rate change of 8.5 cm yr−1 w.e., 10 ‰ for a change in the dominant snow deposition season between winter and summer, and 10 ‰ for a TCO change of 100 DU (Dobson units). Here we set the framework for the interpretation of a 1000-year ice core record of δ15N-NO−3 from DML. Ice core δ15N-NO−3 records at DML will be less sensitive to changes in UV than at Dome C; however the higher snow accumulation rate and more accurate dating at DML allows for higher-resolution δ15N-NO−3 records.

Programme: 1177

http://publi.ipev.fr/polar_references/show.php?record=7855

Weisen Shen, Douglas A. Wiens, Sridhar Anandakrishnan, Richard C. Aster, Peter Gerstoft, Peter D. Bromirski, Samantha E. Hansen, Ian W. D. Dalziel, David S. Heeszel, Audrey D. Huerta, Andrew A. Nyblade, Ralph Stephen, Terry J. Wilson, J. Paul Winberry. (2018). The Crust and Upper Mantle Structure of Central and West Antarctica From Bayesian Inversion of Rayleigh Wave and Receiver Functions (Vol. 123).

Elena Dobrică, Ryan C. Ogliore, Cécile Engrand, Kazuhide Nagashima, Adrian J. Brearley. (2019). Mineralogy and oxygen isotope systematics of magnetite grains and a magnetite-dolomite assemblage in hydrated fine-grained Antarctic micrometeorites (Vol. 54).

Abstract: We report the mineralogy and texture of magnetite grains, a magnetite-dolomite assemblage, and the adjacent mineral phases in five hydrated fine-grained Antarctic micrometeorites (H-FgMMs). Additionally, we measured the oxygen isotopic composition of magnetite grains and a magnetite-dolomite assemblage in these samples. Our mineralogical study shows that the secondary phases identified in H-FgMMs have similar textures and chemical compositions to those described previously in other primitive solar system materials, such as carbonaceous chondrites. However, the oxygen isotopic compositions of magnetite in H-FgMMs span a range of ∆17O values from +1.3‰ to +4.2‰, which is intermediate between magnetites measured in carbonaceous and ordinary chondrites (CCs and OCs). The δ18O values of magnetites in one H-FgMM have a 27‰ mass-dependent spread in a single 100 × 200 μm particle, indicating that there was a localized control of the fluid composition, probably due to a low water-to-rock mass ratio. The ∆17O values of magnetite indicate that H-FgMMs sampled a different aqueous fluid than ordinary and carbonaceous chondrites, implying that the source of H-FgMMs is probably distinct from the asteroidal source of CCs and OCs. Additionally, we analyzed the oxygen isotopic composition of a magnetite-dolomite assemblage in one of the H-FgMMs (sample 03-36-46) to investigate the temperature at which these minerals coprecipitated. We have used the oxygen isotope fractionation between the coexisting magnetite and dolomite to infer a precipitation temperature between 160 and 280 °C for this sample. This alteration temperature is 100–200 °C warmer than that determined from a calcite-magnetite assemblage from the CR2 chondrite Al Rais, but similar to the estimated temperature of aqueous alteration for unequilibrated OCs, CIs, and CMs. This suggests that the sample 03-36-46 could come from a parent body that was large enough to attain temperatures as high as the OCs, CIs, and CMs, which implies an asteroidal origin for this particular H-FgMM.

Programme: 1120

http://publi.ipev.fr/polar_references/show.php?record=7898

Chengsheng Zhu, Maximilian Miller, Nicholas Lusskin, Benoît Bergk Pinto, Lorrie Maccario, Max Häggblom, Timothy Vogel, Catherine Larose, Yana Bromberg. (2020). Snow microbiome functional analyses reveal novel aspects of microbial metabolism of complex organic compounds (Vol. 9).

O. I. Berngardt, J.-P. St- Maurice, J. M. Ruohoniemi, A. Marchaudon. (2022). Seasonal and Diurnal Dynamics of Radio Noise for 8–20 MHz Poleward-Oriented Mid-Latitude Radars (Vol. 57).

Baptiste Le Bourg, Thomas Saucède, Anouk Charpentier, Gilles Lepoint, Loïc N. Michel. (2022). What is the menu today in a subantarctic kelp food web from the Kerguelen Islands? Phytodetritus, phytoplankton and phytobenthos; not living kelp (Vol. 169).

Guillaumot Charlène, Danis Bruno, Saucède Thomas. (2020). Selecting environmental descriptors is critical for modelling the distribution of Antarctic benthic species (Vol. 43). Bachelor's thesis, , .

Deborah Verfaillie, Vincent Favier, Hubert Gallée, Xavier Fettweis, Cécile Agosta, Vincent Jomelli. (2019). Regional modeling of surface mass balance on the Cook Ice Cap, Kerguelen Islands (49∘S, 69∘E) (Vol. 53).

Francesco Enrichi, Dorthe Dahl-Jensen, Jørgen Peder Steffensen, Carlo Barbante. (2021). Theoretical and Experimental Analysis for Cleaning Ice Cores from EstisolTM 140 Drill Liquid (Vol. 11).

Jonas J. Lembrechts, Johan van den Hoogen, Juha Aalto, Michael B. Ashcroft, Pieter De Frenne, Julia Kemppinen, Martin Kopecký, Miska Luoto, Ilya M. D. Maclean, Thomas W. Crowther, Joseph J. Bailey, Stef Haesen, David H. Klinges, Pekka Niittynen, Brett R. Scheffers, Koenraad Van Meerbeek, Peter Aartsma, Otar Abdalaze, Mehdi Abedi, Rien Aerts, Negar Ahmadian, Antje Ahrends, Juha M. Alatalo, Jake M. Alexander, Camille Nina Allonsius, Jan Altman, Christof Ammann, Christian Andres, Christopher Andrews, Jonas Ardö, Nicola Arriga, Alberto Arzac, Valeria Aschero, Rafael L. Assis, Jakob Johann Assmann, Maaike Y. Bader, Khadijeh Bahalkeh, Peter Barančok, Isabel C. Barrio, Agustina Barros, Matti Barthel, Edmund W. Basham, Marijn Bauters, Manuele Bazzichetto, Luca Belelli Marchesini, Michael C. Bell, Juan C. Benavides, José Luis Benito Alonso, Bernd J. Berauer, Jarle W. Bjerke, Robert G. Björk, Mats P. Björkman, Katrin Björnsdóttir, Benjamin Blonder, Pascal Boeckx, Julia Boike, Stef Bokhorst, Bárbara N. S. Brum, Josef Brůna, Nina Buchmann, Pauline Buysse, José Luís Camargo, Otávio C. Campoe, Onur Candan, Rafaella Canessa, Nicoletta Cannone, Michele Carbognani, Jofre Carnicer, Angélica Casanova-Katny, Simone Cesarz, Bogdan Chojnicki, Philippe Choler, Steven L. Chown, Edgar F. Cifuentes, Marek Čiliak, Tamara Contador, Peter Convey, Elisabeth J. Cooper, Edoardo Cremonese, Salvatore R. Curasi, Robin Curtis, Maurizio Cutini, C. Johan Dahlberg, Gergana N. Daskalova, Miguel Angel de Pablo, Stefano Della Chiesa, Jürgen Dengler, Bart Deronde, Patrice Descombes, Valter Di Cecco, Michele Di Musciano, Jan Dick, Romina D. Dimarco, Jiri Dolezal, Ellen Dorrepaal, Jiří Dušek, Nico Eisenhauer, Lars Eklundh, Todd E. Erickson, Brigitta Erschbamer, Werner Eugster, Robert M. Ewers, Dan A. Exton, Nicolas Fanin, Fatih Fazlioglu, Iris Feigenwinter, Giuseppe Fenu, Olga Ferlian, M. Rosa Fernández Calzado, Eduardo Fernández-Pascual, Manfred Finckh, Rebecca Finger Higgens, T'ai G. W. Forte, Erika C. Freeman, Esther R. Frei, Eduardo Fuentes-Lillo, Rafael A. García, María B. García, Charly Géron, Mana Gharun, Dany Ghosn, Khatuna Gigauri, Anne Gobin, Ignacio Goded, Mathias Goeckede, Felix Gottschall, Keith Goulding, Sanne Govaert, Bente Jessen Graae, Sarah Greenwood, Caroline Greiser, Achim Grelle, Benoit Guénard, Mauro Guglielmin, Joannès Guillemot, Peter Haase, Sylvia Haider, Aud H. Halbritter, Maroof Hamid, Albin Hammerle, Arndt Hampe, Siri V. Haugum, Lucia Hederová, Bernard Heinesch, Carole Helfter, Daniel Hepenstrick, Maximiliane Herberich, Mathias Herbst, Luise Hermanutz, David S. Hik, Raúl Hoffrén, Jürgen Homeier, Lukas Hörtnagl, Toke T. Høye, Filip Hrbacek, Kristoffer Hylander, Hiroki Iwata, Marcin Antoni Jackowicz-Korczynski, Hervé Jactel, Järvi Järveoja, Szymon Jastrzębowski, Anke Jentsch, Juan J. Jiménez, Ingibjörg S. Jónsdóttir, Tommaso Jucker, Alistair S. Jump, Radoslaw Juszczak, Róbert Kanka, Vít Kašpar, George Kazakis, Julia Kelly, Anzar A. Khuroo, Leif Klemedtsson, Marcin Klisz, Natascha Kljun, Alexander Knohl, Johannes Kobler, Jozef Kollár, Martyna M. Kotowska, Bence Kovács, Juergen Kreyling, Andrea Lamprecht, Simone I. Lang, Christian Larson, Keith Larson, Kamil Laska, Guerric le Maire, Rachel I. Leihy, Luc Lens, Bengt Liljebladh, Annalea Lohila, Juan Lorite, Benjamin Loubet, Joshua Lynn, Martin Macek, Roy Mackenzie, Enzo Magliulo, Regine Maier, Francesco Malfasi, František Máliš, Matěj Man, Giovanni Manca, Antonio Manco, Tanguy Manise, Paraskevi Manolaki, Felipe Marciniak, Radim Matula, Ana Clara Mazzolari, Sergiy Medinets, Volodymyr Medinets, Camille Meeussen, Sonia Merinero, Rita de Cássia Guimarães Mesquita, Katrin Meusburger, Filip J. R. Meysman, Sean T. Michaletz, Ann Milbau, Dmitry Moiseev, Pavel Moiseev, Andrea Mondoni, Ruth Monfries, Leonardo Montagnani, Mikel Moriana-Armendariz, Umberto Morra di Cella, Martin Mörsdorf, Jonathan R. Mosedale, Lena Muffler, Miriam Muñoz-Rojas, Jonathan A. Myers, Isla H. Myers-Smith, Laszlo Nagy, Marianna Nardino, Ilona Naujokaitis-Lewis, Emily Newling, Lena Nicklas, Georg Niedrist, Armin Niessner, Mats B. Nilsson, Signe Normand, Marcelo D. Nosetto, Yann Nouvellon, Martin A. Nuñez, Romà Ogaya, Jérôme Ogée, Joseph Okello, Janusz Olejnik, Jørgen Eivind Olesen, Øystein H. Opedal, Simone Orsenigo, Andrej Palaj, Timo Pampuch, Alexey V. Panov, Meelis Pärtel, Ada Pastor, Aníbal Pauchard, Harald Pauli, Marian Pavelka, William D. Pearse, Matthias Peichl, Loïc Pellissier, Rachel M. Penczykowski, Josep Penuelas, Matteo Petit Bon, Alessandro Petraglia, Shyam S. Phartyal, Gareth K. Phoenix, Casimiro Pio, Andrea Pitacco, Camille Pitteloud, Roman Plichta, Francesco Porro, Miguel Portillo-Estrada, Jérôme Poulenard, Rafael Poyatos, Anatoly S. Prokushkin, Radoslaw Puchalka, Mihai Pușcaș, Dajana Radujković, Krystal Randall, Amanda Ratier Backes, Sabine Remmele, Wolfram Remmers, David Renault, Anita C. Risch, Christian Rixen, Sharon A. Robinson, Bjorn J. M. Robroek, Adrian V. Rocha, Christian Rossi, Graziano Rossi, Olivier Roupsard, Alexey V. Rubtsov, Patrick Saccone, Clotilde Sagot, Jhonatan Sallo Bravo, Cinthya C. Santos, Judith M. Sarneel, Tobias Scharnweber, Jonas Schmeddes, Marius Schmidt, Thomas Scholten, Max Schuchardt, Naomi Schwartz, Tony Scott, Julia Seeber, Ana Cristina Segalin de Andrade, Tim Seipel, Philipp Semenchuk, Rebecca A. Senior, Josep M. Serra-Diaz, Piotr Sewerniak, Ankit Shekhar, Nikita V. Sidenko, Lukas Siebicke, Laura Siegwart Collier, Elizabeth Simpson, David P. Siqueira, Zuzana Sitková, Johan Six, Marko Smiljanic, Stuart W. Smith, Sarah Smith-Tripp, Ben Somers, Mia Vedel Sørensen, José João L. L. Souza, Bartolomeu Israel Souza, Arildo Souza Dias, Marko J. Spasojevic, James D. M. Speed, Fabien Spicher, Angela Stanisci, Klaus Steinbauer, Rainer Steinbrecher, Michael Steinwandter, Michael Stemkovski, Jörg G. Stephan, Christian Stiegler, Stefan Stoll, Martin Svátek, Miroslav Svoboda, Torbern Tagesson, Andrew J. Tanentzap, Franziska Tanneberger, Jean-Paul Theurillat, Haydn J. D. Thomas, Andrew D. Thomas, Katja Tielbörger, Marcello Tomaselli, Urs Albert Treier, Mario Trouillier, Pavel Dan Turtureanu, Rosamond Tutton, Vilna A. Tyystjärvi, Masahito Ueyama, Karol Ujházy, Mariana Ujházyová, Domas Uogintas, Anastasiya V. Urban, Josef Urban, Marek Urbaniak, Tudor-Mihai Ursu, Francesco Primo Vaccari, Stijn Van de Vondel, Liesbeth van den Brink, Maarten Van Geel, Vigdis Vandvik, Pieter Vangansbeke, Andrej Varlagin, G. F. Veen, Elmar Veenendaal, Susanna E. Venn, Hans Verbeeck, Erik Verbrugggen, Frank G. A. Verheijen, Luis Villar, Luca Vitale, Pascal Vittoz, Maria Vives-Ingla, Jonathan von Oppen, Josefine Walz, Runxi Wang, Yifeng Wang, Robert G. Way, Ronja E. M. Wedegärtner, Robert Weigel, Jan Wild, Matthew Wilkinson, Martin Wilmking, Lisa Wingate, Manuela Winkler, Sonja Wipf, Georg Wohlfahrt, Georgios Xenakis, Yan Yang, Zicheng Yu, Kailiang Yu, Florian Zellweger, Jian Zhang, Zhaochen Zhang, Peng Zhao, Klaudia Ziemblińska, Reiner Zimmermann, Shengwei Zong, Viacheslav I. Zyryanov, Ivan Nijs, Jonathan Lenoir. (2022). Global maps of soil temperature (Vol. 28).

Abstract: Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-km2 resolution for 0–5 and 5–15 cm soil depth. These maps were created by calculating the difference (i.e. offset) between in situ soil temperature measurements, based on time series from over 1200 1-km2 pixels (summarized from 8519 unique temperature sensors) across all the world's major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10°C (mean = 3.0 ± 2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 ± 2.3°C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (−0.7 ± 2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications.

Keywords: bioclimatic variables global maps microclimate near-surface temperatures soil temperature soil-dwelling organisms temperature offset weather stations

Programme: 136

http://publi.ipev.fr/polar_references/show.php?record=8368