As a national initiative and through a partnership with different German institutions, CSC will produce and deliver useful, authoritative, and timely science-based knowledge, using Earth system observations, model predictions/projections and analysis. In so doing, the CSC will develop and provide climate information and knowledge to help deliver on the following objectives:

• mitigate the causes of environmental changes and
• manage climate-related risks, opportunities and impacts.

In order to fulfill its "one-stop-shop"-function, CSC is organized in five departments: climate systems, management of natural resources, economics and policy, communication and strategic development. These departments work together in an interdisciplinary way. Two of the departments, the department dealing with natural resource management and especially the climate system department are directly involved in the RSSC-project. The focus of the climate system department lies in generating and providing regional climate change information. This is achieved by using a global to local multi-model chain to create ensembles of regional climate change projections, which are directly linked or fed into impact assessment models within the individual sectors, for example, land use change, ecosystems and biodiversity, water management or health. This approach, together with a rigorous treatment of associated uncertainties, allows the establishment of robust information about past and future changes.

On the basis of existing and new regional climate change projections the CSC delivers information tailored to the needs of users and customers, and in general associated to questions posed by users. This includes - in addition to direct model outputs - maps and atlases, time series and diagrams for probability distributions as well as for indices related to the needs within the sectors, like dry days, heat spells, wind zones.

Headline messages, summary statistics, briefing reports, guidance documents, scientific reports, summary and numerical tools to work with data and visualise the results will be provided together with training sessions at the CSC and abroad. The focus lies on the use of hardware, the methodology used to achieve regional climate change information and the technical tools to analyse and visualize the data.

• Development and application of the regional climate model REMO (http://www.remo-rcm.org/), which has been used over the last 20 years for regional climate projections all over the World. CSC/REMO takes part in the WCRP CORDEX activity for IPCC-AR5


• Development of regionally coupled modelling systems (eg. regional coupling of atmosphere-ocean, atmosphere-hydrology and atmosphere-land use/irrigation)


• Large experience in regional climate modelling, analysis of changes in extremes, robustness of regional climate change pattern and changes in the water cycle, as well as in how to link these data with impact models


• Investigation of climate change information for impact, adaptation and vulnerability assessments, and delivery to users in the field of climate service


• Educational and guidance capacities, including staging of summer schools, workshops and practical sessions, on how to use regional climate models and statistical tools, how to analyse, interpret and apply regional climate modelling data, and on communication of uncertainties.

BIOTA Southern Africa (BIOdiversity Monitoring Transect Analysis; BMBF funded): Interdisciplinary project focusing on impacts of climate and land management on the biodiversity of the southern African region. Within BIOTA, we provided high-resolution climate simulations for the southern African region for current and future climate.

CONGO (GTZ funded, in starting phase): The project aims at providing relevant national and regional decision makers with climate change scenarios for the River Congo Basin in order to allow these decision makers i) to adapt their management strategies related to natural resources (such as forests, water, agriculture) to climate change and ii) to strengthen the science base for their interest in the post-Kyoto negotiations context. A first analysis of the climate change impact on forest- and water management and of the use of water resources in agriculture will be established.

CORDEX (COordinated Regional climate Downscaling EXperiment; WCRP): Generation of multi-model ensembles of high-resolution regional climate projections for the African continent for input to impact/adaptation work and to the IPCC 5th Assessment Report (AR5).

ENSEMBLES-AMMA (EU funded): Although independent RCM studies have been undertaken in the past, the RCM simulations produced by ENSEMBLES for the West African domain provide an unprecedented resource for climate research in this region. These coordinated experiments allow for an evaluation of model uncertainty in this tropical region, in a similar manner to what has been undertaken for the European domain. Not least intraseasonal and interannual characteristics of the West African Monsoon (WAM) are of particular interest, as well as land-atmosphere interactions. The results indicate promising skill in the models' ability to represent the dominant spatial features and the seasonal cycle of WAM rainfall.

GENUS (Geochemistry and Ecology of the Namibian Upwelling System, BMBF funded): GENUS aims to clarify relationships between climate change, biogeochemical cycles, and ecosystem structure in the large marine ecosystem of the northern Benguela / Namibian Coast (SW Africa).

IMPETUS (Weblink, BMBf funded): In the IMPETUS project thorough investigations of all aspects of the hydrological cycle are carried out within two river catchments in West Africa: the wadi Drâa in the south east of Morocco and the Ouémé River in Benin. This choice is motivated by the indications found that since the 1970s the droughts north and south of the Sahara have been related.

The interdisciplinary POTATO project (GTZ funded) is about the participatory development and testing of strategies to reduce climate vulnerability of poor farm households in East Africa through innovations in potato and sweet potato technologies and enabling policies. High resolution climate data is used by the project partners to further assess impacts of new potato and sweet potato technologies via the Trade off Analysis methodology.

The tasks dedicated to the proposed RSSC are clearly related to the needs for understanding the dynamic atmospheric flow systems and their variability as well as the regional feedbacks involved. Large emphasis should be given to knowledge transfer and capacity building to facilitate the RSSC in analysing existing observations and climate change projections, in running global and regional modelling systems, and in assessing possible future scenarios and associated uncertainties. Major challenges of the climate change studies within RSSC are the publication of regional climate assessments and the release of customised robust climate change information to users.

Specific tasks:

Regional climate assessment:
The understanding of the developments of the climatic conditions during the last decades is prerequisite for modelling of possible future climate changes. Therefore existing observations from all possible sources ("in situ" measurements as well as remote sensing information) will be analysed to assess the regional climate. This includes meteorological variables such as temperature and precipitation, as well as wind and radiation properties. A close link between the partners from the national weather services and the climate institutes as well as to hydrological processes and sustainable water management is essential and important to study long data records. From this assessment a clear view of past and on-going changes evolves and progress in understanding variability in the region is expected.

Regional climate change and scenario development
Existing global IPCC projections show possible strong warming and drying until the end of this century. Unfortunately only very few regional climate change scenarios are available, which provide high resolution regional climate information with many details. The development of sustainable land management however needs information of possible temperature and precipitation changes on acre space scales and sub daily times scales. This data can be established within the RSSC, taking advantage of existing modelling systems and the development of regional scenarios. Land use/land cover changes will affect regional and local climatic conditions and must be included in high resolution regional climate change projections.

Uncertainty assessment: variability and change
Uncertainties in observations due to many different sources as well as uncertainties in modelling systems and possible emissions scenarios make it difficult to provide tightly constrained information for management purposes. Nevertheless, this information is needed. Therefore the delivery of robust regional climate change signals (e.g. providing possible climate change information as ranges or corridors) on high resolution for climate change adaptation in the region created within the existing RSSC in Africa is one of the ultimate goals of this proposal.

It is planned to help building up a regional computing centre with access to best possible and robust information of regional climate change. This includes capacity building on two sides:

• regional experts who are capable to run global and regional climate models and to interpret their results
• hardware and storage systems

Joint planning of the hardware requirements, training periods abroad and joint scientific projects will bring the groups together and guarantees the efficient use of a regional computing centre.

Software:

• Development of a regional climate model (e.g. REMO) adapted to the RSSC-region and in an easily manageable way: "personal REMO".
• Joint development of tools for tailoring regional climate model results to user needs
• Analysis tool for the CORDEX Africa regional climate change IPCC AR5 data and uncertainty assessment

Education:

• summer schools on regional climate change, linking regional climate information to impact models and on adaptation
• workshops and practical sessions on
  • how to use regional climate models (eg REMO) and statistical tools,
  • how to analyse regional climate modelling data and achieve climate change indicators
  • how to analyse robust pattern and uncertainty
  • on communication of uncertainties
  • and guidance on the work with regional climate change information
  • climate consultancy


• training at CSC and abroad on how to interpret regional climate change information
• supervision of doctoral thesis

Frenger, I. (2008). Untersuchung der Auswirkungen von Landoberflächenänderungen in Westafrika auf das regionale Klima: Simulationen mit dem Klimamodell REMO. Master Thesis, University of Hamburg, Hamburg, Germany.

Haensler, A. Hagemann, S. & Jacob, D. (2010): How the future climate of the southern African region might look like: Results of a high-resolution regional climate change projection. Nova Acta Leopoldina, 112(384), 183-193.

Haensler, A. Hagemann, S. & Jacob, D.: Dynamical downscaling of ERA40 reanalysis data over southern Africa: added value in the representation of seasonal rainfall characteristics. submitted to the International Journal of Climatology, 2009.

Jacob D., Bärring L., Christensen O.-B., Christensen J-H., de Castro M., Deque M., Giorgi F., Hagemann St., Hirschi M., Jones R., Kjellström E., Lenderink G., Rockel B., Sanchez Sanchez E., Schär Ch., Seneviratne S., Somot S., van Ulden A., van den Hurk B., (2007): An inter- comparison of regional climate models for Europe: Design of the experiments and model performance. Climatic Change, Vol. 81, Supplement 1, pp 31-52

Jacob D., Göttel H., Kotlarski S., Lorenz Ph, Sieck K. (2008): Klimaauswirkungen und Anpassung in Deutschland -- Phase 1: Erstellung regionaler Klimaszenarien für Deutschland, Abschlussbericht zum UFOPLAN Vorhaben 204 41 13

Jacob D. (2009): 'Regional Climate Models: Linking Global Climate Change to Local Impacts' in the Springer Encyclopaedia of Complexity and Systems Science, 7591-7602

Klehmet, Katharina: Klima in Ostafrika - Modellvalidierung und Untersuchung regionaler Charakteristika. Master thesis, University of Bonn, Germany

Paeth H., Born K, Girmes R., Podzun R , Jacob D.(2009): Regional Climate change in Tropical and Northern Africa due to Greenhouse Forcing and Land Use Change, Journal of Climate, Vol. 22, pp 114-132

Paeth H., Born K., Podzun R., Jacob D. (2005): Regional dynamical downscaling over West Africa: model evaluation and comparison of wet and dry days. Meteorologische Zeitschrift Vol. 14, pp 349-367