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  • Author or Editor: Claas Teichmann x
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Tomáš Púčik
,
Pieter Groenemeijer
,
Anja T. Rädler
,
Lars Tijssen
,
Grigory Nikulin
,
Andreas F. Prein
,
Erik van Meijgaard
,
Rowan Fealy
,
Daniela Jacob
, and
Claas Teichmann

Abstract

The occurrence of environmental conditions favorable for severe convective storms was assessed in an ensemble of 14 regional climate models covering Europe and the Mediterranean with a horizontal grid spacing of 0.44°. These conditions included the collocated presence of latent instability and strong deep-layer (surface to 500 hPa) wind shear, which is conducive to the severe and well-organized convective storms. The occurrence of precipitation in the models was used as a proxy for convective initiation. Two climate scenarios (RCP4.5 and RCP8.5) were investigated by comparing two future periods (2021–50 and 2071–2100) to a historical period (1971–2000) for each of these scenarios. The ensemble simulates a robust increase (change larger than twice the ensemble sample standard deviation) in the frequency of occurrence of unstable environments (lifted index ≤ −2) across central and south-central Europe in the RCP8.5 scenario in the late twenty-first century. This increase coincides with the increase in lower-tropospheric moisture. Smaller, less robust changes were found until midcentury in the RCP8.5 scenario and in the RCP4.5 scenario. Changes in the frequency of situations with strong (≥15 m s−1) deep-layer shear were found to be small and not robust, except across far northern Europe, where a decrease in shear is projected. By the end of the century, the simultaneous occurrence of latent instability, strong deep-layer shear, and model precipitation is simulated to increase by up to 100% across central and eastern Europe in the RCP8.5 and by 30%–50% in the RCP4.5 scenario. Until midcentury, increases in the 10%–25% range are forecast for most regions. A large intermodel variability is present in the ensemble and is primarily due to the uncertainties in the frequency of the occurrence of unstable environments.

Full access
Jonathan Spinoni
,
Paulo Barbosa
,
Edoardo Bucchignani
,
John Cassano
,
Tereza Cavazos
,
Jens H. Christensen
,
Ole B. Christensen
,
Erika Coppola
,
Jason Evans
,
Beate Geyer
,
Filippo Giorgi
,
Panos Hadjinicolaou
,
Daniela Jacob
,
Jack Katzfey
,
Torben Koenigk
,
René Laprise
,
Christopher J. Lennard
,
M. Levent Kurnaz
,
Delei Li
,
Marta Llopart
,
Niall McCormick
,
Gustavo Naumann
,
Grigory Nikulin
,
Tugba Ozturk
,
Hans-Juergen Panitz
,
Rosmeri Porfirio da Rocha
,
Burkhardt Rockel
,
Silvina A. Solman
,
Jozef Syktus
,
Fredolin Tangang
,
Claas Teichmann
,
Robert Vautard
,
Jürgen V. Vogt
,
Katja Winger
,
George Zittis
, and
Alessandro Dosio

Abstract

Two questions motivated this study: 1) Will meteorological droughts become more frequent and severe during the twenty-first century? 2) Given the projected global temperature rise, to what extent does the inclusion of temperature (in addition to precipitation) in drought indicators play a role in future meteorological droughts? To answer, we analyzed the changes in drought frequency, severity, and historically undocumented extreme droughts over 1981–2100, using the standardized precipitation index (SPI; including precipitation only) and standardized precipitation-evapotranspiration index (SPEI; indirectly including temperature), and under two representative concentration pathways (RCP4.5 and RCP8.5). As input data, we employed 103 high-resolution (0.44°) simulations from the Coordinated Regional Climate Downscaling Experiment (CORDEX), based on a combination of 16 global circulation models (GCMs) and 20 regional circulation models (RCMs). This is the first study on global drought projections including RCMs based on such a large ensemble of RCMs. Based on precipitation only, ~15% of the global land is likely to experience more frequent and severe droughts during 2071–2100 versus 1981–2010 for both scenarios. This increase is larger (~47% under RCP4.5, ~49% under RCP8.5) when precipitation and temperature are used. Both SPI and SPEI project more frequent and severe droughts, especially under RCP8.5, over southern South America, the Mediterranean region, southern Africa, southeastern China, Japan, and southern Australia. A decrease in drought is projected for high latitudes in Northern Hemisphere and Southeast Asia. If temperature is included, drought characteristics are projected to increase over North America, Amazonia, central Europe and Asia, the Horn of Africa, India, and central Australia; if only precipitation is considered, they are found to decrease over those areas.

Open access
Filippo Giorgi
,
Erika Coppola
,
Daniela Jacob
,
Claas Teichmann
,
Sabina Abba Omar
,
Moetasim Ashfaq
,
Nikolina Ban
,
Katharina Bülow
,
Melissa Bukovsky
,
Lars Buntemeyer
,
Tereza Cavazos
,
James Ciarlo`
,
Rosmeri Porfirio da Rocha
,
Sushant Das
,
Fabio di Sante
,
Jason P. Evans
,
Xuejie Gao
,
Graziano Giuliani
,
Russell H. Glazer
,
Peter Hoffmann
,
Eun-Soon Im
,
Gaby Langendijk
,
Ludwig Lierhammer
,
Marta Llopart
,
Sebastial Mueller
,
Rosa Luna-Nino
,
Rita Nogherotto
,
Emanuela Pichelli
,
Francesca Raffaele
,
Michelle Reboita
,
Diana Rechid
,
Armelle Remedio
,
Thomas Remke
,
Windmanagda Sawadogo
,
Kevin Sieck
,
José Abraham Torres-Alavez
, and
Torsten Weber

Abstract

We describe the first effort within the Coordinated Regional Climate Downscaling Experiment–Coordinated Output for Regional Evaluation, or CORDEX-CORE EXP-I. It consists of a set of twenty-first-century projections with two regional climate models (RCMs) downscaling three global climate model (GCM) simulations from the CMIP5 program, for two greenhouse gas concentration pathways (RCP8.5 and RCP2.6), over nine CORDEX domains at ∼25-km grid spacing. Illustrative examples from the initial analysis of this ensemble are presented, covering a wide range of topics, such as added value of RCM nesting, extreme indices, tropical and extratropical storms, monsoons, ENSO, severe storm environments, emergence of change signals, and energy production. They show that the CORDEX-CORE EXP-I ensemble can provide downscaled information of unprecedented comprehensiveness to increase understanding of processes relevant for regional climate change and impacts, and to assess the added value of RCMs. The CORDEX-CORE EXP-I dataset, which will be incrementally augmented with new simulations, is intended to be a public resource available to the scientific and end-user communities for application to process studies, impacts on different socioeconomic sectors, and climate service activities. The future of the CORDEX-CORE initiative is also discussed.

Full access
Javier Diez-Sierra
,
Maialen Iturbide
,
José M. Gutiérrez
,
Jesús Fernández
,
Josipa Milovac
,
Antonio S. Cofiño
,
Ezequiel Cimadevilla
,
Grigory Nikulin
,
Guillaume Levavasseur
,
Erik Kjellström
,
Katharina Bülow
,
András Horányi
,
Anca Brookshaw
,
Markel García-Díez
,
Antonio Pérez
,
Jorge Baño-Medina
,
Bodo Ahrens
,
Antoinette Alias
,
Moetasim Ashfaq
,
Melissa Bukovsky
,
Erasmo Buonomo
,
Steven Caluwaerts
,
Sin Chan Chou
,
Ole B. Christensen
,
James M. Ciarlò
,
Erika Coppola
,
Lola Corre
,
Marie-Estelle Demory
,
Vladimir Djurdjevic
,
Jason P. Evans
,
Rowan Fealy
,
Hendrik Feldmann
,
Daniela Jacob
,
Sanjay Jayanarayanan
,
Jack Katzfey
,
Klaus Keuler
,
Christoph Kittel
,
Mehmet Levent Kurnaz
,
René Laprise
,
Piero Lionello
,
Seth McGinnis
,
Paola Mercogliano
,
Pierre Nabat
,
Barış Önol
,
Tugba Ozturk
,
Hans-Jürgen Panitz
,
Dominique Paquin
,
Ildikó Pieczka
,
Francesca Raffaele
,
Armelle Reca Remedio
,
John Scinocca
,
Florence Sevault
,
Samuel Somot
,
Christian Steger
,
Fredolin Tangang
,
Claas Teichmann
,
Piet Termonia
,
Marcus Thatcher
,
Csaba Torma
,
Erik van Meijgaard
,
Robert Vautard
,
Kirsten Warrach-Sagi
,
Katja Winger
, and
George Zittis

Abstract

The collaboration between the Coordinated Regional Climate Downscaling Experiment (CORDEX) and the Earth System Grid Federation (ESGF) provides open access to an unprecedented ensemble of regional climate model (RCM) simulations, across the 14 CORDEX continental-scale domains, with global coverage. These simulations have been used as a new line of evidence to assess regional climate projections in the latest contribution of the Working Group I (WGI) to the IPCC Sixth Assessment Report (AR6), particularly in the regional chapters and the Atlas. Here, we present the work done in the framework of the Copernicus Climate Change Service (C3S) to ­assemble a consistent worldwide CORDEX grand ensemble, aligned with the deadlines and ­activities of IPCC AR6. This work addressed the uneven and heterogeneous availability of CORDEX ESGF data by supporting publication in CORDEX domains with few archived simulations and performing quality control. It also addressed the lack of comprehensive documentation by compiling information from all contributing regional models, allowing for an informed use of data. In addition to presenting the worldwide CORDEX dataset, we assess here its consistency for precipitation and temperature by comparing climate change signals in regions with overlapping CORDEX domains, obtaining overall coincident regional climate change signals. The C3S CORDEX dataset has been used for the assessment of regional climate change in the IPCC AR6 (and for the interactive Atlas) and is available through the Copernicus Climate Data Store (CDS).

Open access