Research

Land-climate interactions and their role in the climate system

Continents and oceans are the lower boundary for the atmosphere, with which they exchange water, energy and chemical compounds such as CO2. Similar to the oceans, which significantly contribute to climate variability by storage and exchanges of heat, land areas have a strong impact on climate variability through water storage (soil moisture, groundwater, snow) and evapotranspiration. Beside its significance as water input to the atmosphere, evapotranspiration is also part of the land energy balance and is tightly coupled with CO2 assimilation from vegetation. Moreover, land cover (vegetation, bare ground, snow, ice) also impacts albedo and the radiation balance. Hence interactions between land and the climate system are manifold and strongly interconnected. As an example, soil moisture-temperature coupling has been found to be a key driver of summer temperature variability in Europe, both in present (Mediterranean) and future (Northern and Eastern Europe) climate (external pageSeneviratne et al. 2006, Nature). Gradual changes in soil moisture-coupling take place as global warming unfolds and induces shifts of climate regimes on the continent.

Despite their key role for the climate system, land-climate interactions are still the subject of significant uncertainties (external pageSeneviratne et al. 2010, Earth-Science Reviews). A major issue is the lack of direct observations of the relevant climate variables (soil moisture, evapotranspiration), which impedes the understanding of the associated processes and their necessary validation in climate models. Hence, a focus of our research group is the analysis of existing observations, the intercomparison and merging of observation-based datasets, and the conducting of field experiments in order to reduce uncertainties and better constrain models. In particular, we investigate the definition of indirect diagnostics for the validation of land-climate interactions in climate models.

Research Areas

We use several modelling tools, including regional and global climate models (external pageCOSMO-CLM, ECHAM) as well as land surface models (external pageCommunity Land Model (CLM), Terra_ML), to investigate interactions between land and climate, in particular by way of sensitivity experiments. We are interested in the quantification of land-atmosphere coupling and of individual land-atmosphere feedbacks at the regional and global scale, as well as in their role relative to other drivers of climate variability (radiation, sea surface temperatures). Special areas of interests are extreme events (droughts, heat waves, heavy precipitation events), seasonal forecasting, and modifications with global warming.

We focus on the analysis of processes at the land-atmosphere interface, based on existing data (ground observations, satellite observations, observation-based datasets, model data). We investigate in particular processes controlling soil moisture and land processes in general (droughts, vegetation, snow cover, ecosystem exchanges, land water and energy cycles) as well as land-atmosphere interactions and feedbacks. An important aspect of our research is the validation of the corresponding processes and interactions in climate and land surface models.

Activities in this area:

An important research area of our group concerns the evaluation and intercomparison of existing land datasets, as well as the development of merged datasets based on several data sources. We recently initiated an intercomparison exercise sponsored by external pageGEWEX and external pageILEAPS, LandFLUX-EVAL, aimed at the evaluation of current observation-based evapotranspiration datasets and the development of a reference benchmarking dataset. Furthermore, we have the climate lead of the external pageESA Soil moisture Climate Change Initiative (CCI), which aims at evaluating and using soil moisture remote sensing datasets for climate research. We are also newly coordinating the evaluation of observational and reference products for terrestrial Essential Climate Variables (ECVs) within the external pageCopernicus C3S_511 project. Finally, we also maintain a diagnostic dataset (BSWB) of monthly variations in terrestrial water storage for several river basins. The BSWB estimates have been shown to compare well with available observations and are available for 37 river basins.

Since 2008, we are conducting a Switzerland-wide soil moisture measurement campaign (SwissSMEX) funded by SNF, in collaboration with Agroscope ART and MeteoSwiss. This campaign has been now expanded to forest sites, in collaboration with WSL (SwissSMEX-Veg), as well as to the inclusion of lysimeter measurements in Switzerland and neighbouring European countries. The data are used to assess spatio-temporal characteristics of soil moisture and evapotranspiration. Moreover, we are maintaining the Rietholzbach hydrological research station, which has been significantly expanded since 2008 (including now eddy-covariance flux measurements and comprehensive soil moisture measurements).

Selected publications

Padron, R., L. Gudmundsson, B. Decharme, A. Ducharne, D.M. Lawrence, J. Mao, D. Peano, G. Krinner, H. Kim, and S.I. Seneviratne (2020): Observed changes in dry-season water availability attributed to human-induced climate change. Nature Geoscience, 13, 477-481. (external pagelink)

Beusch, L., L. Gudmundsson, S. I. Seneviratne, 2020: Emulating Earth system model temperatures with MESMER: from global mean temperature trajectories to grid-point-level realizations on land. Earth System Dynamics, 11, 139-159. (external pagelink)

Vogel, M. M., J. Zscheischler, R. Wartenburger, D. Dee, S. I. Seneviratne, 2019: Concurrent 2018 hot extremes across Northern Hemisphere due to human-induced climate change. Earth’s Future, 7, 692-703. (external pagelink)

Seneviratne, S.I., J. Rogelj, R. Séférian, R. Wartenburger, M.R. Allen, M. Cain, R.J. Millar, K.L. Ebi, N. Ellis, O. Hoegh-Guldberg, A.J. Payne, C.-F. Schleussner, P. Tschakert, R.F. Warren, 2018: The many possible climates from the Paris Agreement's aim of 1.5°C warming. Nature. 558, 41-49 (external pagelink)

Humphrey, V., J. Zscheischler, P. Ciais, L. Gudmundsson, S. Sitch, S.I. Seneviratne, 2018: Sensitivity of atmospheric CO2 growth rate to observed changes in terrestrial water storage. Nature, 560, 628-631 (external pagelink)

Zscheischler, J., and S.I. Seneviratne, 2017: Dependence of drivers affects risks associated with compound events. Science Advances, 3(6). (external pagelink)
 

Seneviratne, S.I. M. Donat, A.J. Pitman, R. Knutti, and R.L. Wilby, 2016: Allowable CO2 emissions based on regional and impact-related climate targets. Nature, published online. (external pagelink; ETH News; external pageNZZ; external pageTagesanzeiger; external pageBlick; external pageDaily Mail; external pageJapan Times)

Guillod, B.P., B. Orlowsky, D.G. Miralles, A.J. Teuling, and S.I. Seneviratne, 2015: Reconciling spatial and temporal soil moisture effects on afternoon rainfall. Nature Communications, 6, 6443. (external pagelink; ETH Life)

Davin, E.L., S.I. Seneviratne, P. Ciais, A. Olioso, and T. Wang, 2014: Preferential cooling of hot extremes from cropland albedo management. Proc. Natl. Acad. Sci., 111(27), 9757-9761, doi:10.1073/pnas.1317323111 (external pagelink; ETH News; external pageSpiegel; external pageNature News).

Greve, P., B. Orlowsky, B. Mueller, J. Sheffield, M. Reichstein, and S.I. Seneviratne, 2014: Global assessment of trends in wetting and drying over land. Nature Geoscience, 7, 716-721, doi: 10.1038/NGEO2247. (external pagelink; ETH News; external pagePhys.org; external page20 Minuten; external pageSchweizer Bauer; external pageLe Temps; external pageWashington Post (online); external pageNature Geoscience News and Views)

Seneviratne, S.I., M. Donat, B. Mueller, and L.V. Alexander, 2014: No pause in the increase of hot temperature extremes. Nature Climate Change, 4, 161-163. (external pagelink; external pageReuters; external pageThe Economist; external pageSRF2 Wissenschaftsmagazin; external pageCBC; external pageClimate Central)

Seneviratne, S.I., M. Wilhelm, T. Stanelle, B.J.J.M. van den Hurk, S. Hagemann, A. Berg, F. Cheruy, M.E. Higgins, A. Meier, V. Brovkin, M. Claussen, A. Ducharne, J.-L. Dufresne, K.L. Findell, J. Ghattas, D.M. Lawrence, S. Malyshev, M. Rummukainen, and B. Smith, 2013: Impact of soil moisture-climate feedbacks on CMIP5 projections: First results from the GLACE-CMIP5 experiment. Geophys. Res. Lett., 40 (19), 5212-5217 (external pagelink).

Mueller, B., and S.I. Seneviratne, 2012: Hot days induced by precipitation deficits at the global scale. Proceedings of the National Academy of Sciences, 109 (31), 12398-12403, doi: 10.1073/pnas.1204330109. (external pagelink; ETH Life article; external pageTagesAnzeiger; external pageLos Angeles Times; external pageResearch Highlight in Nature Geoscience)

Orlowsky, B., and S.I. Seneviratne, 2012: Global changes in extreme events: Regional and seasonal dimension. Climatic Change, 110, 669-696, doi: 10.1007/s10584-011-0122-9. (external pagelink)

Seneviratne, S.I., and R.D. Koster, 2012: A revised framework for analyzing soil moisture memory in climate data: Derivation and interpretation. J. Hydrometeorology, 13, 404-412, doi: 10.1175/JHM-D-11-044.1. (external pagelink)

Seneviratne, S.I., N. Nicholls, D. Easterling, C.M. Goodess, S. Kanae, J. Kossin, Y. Luo, J. Marengo, K. McInnes, M. Rahimi, M. Reichstein, A. Sorteberg, C. Vera, and X. Zhang, 2012: Changes in climate extremes and their impacts on the natural physical environment. In: Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation [Field, C.B., V. Barros, T.F. Stocker, D. Qin, D.J. Dokken, K.L. Ebi, M.D. Mastrandrea, K.J. Mach, G.-K. Plattner, S.K. Allen, M. Tignor, and P.M. Midgley (eds.)]. A Special Report of Working Groups I and II of the Intergovernmental Panel on Climate Change (IPCC) (external pagelink).

Davin, E.L, R. Stöckli, E.B. Jaeger, S. Levis, and S.I. Seneviratne, 2011: COSMO-CLM2: a new version of the COSMO-CLM model coupled to the Community Land Model. Climate Dynamics, 37, 1889-1907, doi: 10.1007/s00382-011-1019-z. (external pagelink)

Hirschi, M., S.I. Seneviratne, V. Alexandrov, F. Boberg, C. Boroneant, O.B. Christensen, H. Formayer, B. Orlowsky, and P. Stepanek, 2011: Observational evidence for soil-moisture impact on hot extremes in southeastern Europe. Nature Geoscience, 4, 17-21, doi:10.1038/ngeo1032. (external pagelink; external pageNews and Views; ETH Life article)

Seneviratne, S.I., T. Corti, E.L. Davin, M. Hirschi, E.B. Jaeger, I. Lehner, B. Orlowsky, and A.J. Teuling, 2010: Investigating soil moisture-climate interactions in a changing climate: A review. Earth-Science Reviews, 99, 3-4, 125-161, doi:10.1016/j.earscirev.2010.02.004. (external pagelink)

Teuling, A.J., S.I. Seneviratne, R. Stöckli, M. Reichstein, E. Moors, P. Ciais, S. Luyssaert, B. van den Hurk, C. Ammann, C. Bernhofer, E. Dellwik, D. Gianelle, B. Gielen, T. Grünwald, K. Klumpp, L. Montagnani, C. Moureaux, M. Sottocornola, and G. Wohlfahrt, 2010: Contrasting response of European forest and grassland energy exchange to heatwaves. Nature Geoscience, 3, 722-727, doi:10.1038/ngeo950. (external pagelink; ETH life article)

Seneviratne, S.I., R.D. Koster, Z. Guo, P.A. Dirmeyer, E. Kowalczyk, D. Lawrence, P. Liu, C.-H. Lu, D. Mocko, K.W. Oleson, and D. Verseghy, 2006: Soil moisture memory in AGCM simulations: Analysis of Global Land-Atmosphere Coupling Experiment (GLACE) data. J. Hydrometeor., 7, 1090-1112. (external pagelink)

Seneviratne, S.I., D. Lüthi, M. Litschi, and C. Schär, 2006: Land-atmosphere coupling and climate change in Europe. Nature, 443, 205-209. (external pagepdf; external pagesuppl. info.; external pageeditor's summary)

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