Errors and uncertainties introduced by a regional climate model in climate impact assessments: example of crop yield simulations in West Africa

16 pagesInternational audienceThe challenge of estimating the potential impacts of climate change has led to an increasing use of dynamical downscaling to produce fine spatial-scale climate projections for impact assessments. In this work, we analyze if and to what extent the bias in the simulated crop yield can be reduced by using the Weather Research and Forecasting (WRF) regional climate model to downscale ERA-Interim (European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis) rainfall and radiation data. Then, we evaluate the uncertainties resulting from both the choice of the physical parameterizations of the WRF model and its internal variability. Impact assessments were performed at two sites in Sub-Saharan Africa and by using two crop models to simulate Niger pearl millet and Benin maize yields. We find that the use of the WRF model to downscale ERA-Interim climate data generally reduces the bias in the simulated crop yield, yet this reduction in bias strongly depends on the choices in the model setup. Among the physical parameterizations considered, we show that the choice of the land surface model (LSM) is of primary importance. When there is no coupling with a LSM, or when the LSM is too simplistic, the simulated precipitation and then the simulated yield are null, or respectively very low; therefore, coupling with a LSM is necessary. The convective scheme is the second most influential scheme for yield simulation, followed by the shortwave radiation scheme. The uncertainties related to the internal variability of the WRF model are also significant and reach up to 30% of the simulated yields. These results suggest that regional models need to be used more carefully in order to improve the reliability of impact assessments

Books Fit for a King: The Presentation Copies of Martin Bucer's De regno Christi (London, British Library, Royal MS. 8 B. VII) and Johannes Sturm's De periodis (Cambridge, Trinity College, II.12.21 and London, British Library, C.24.e.5)

This article discusses the presentation copies of two sixteenth-century works, Martin Bucer’s De regno Christi and Johannes Sturm’s De periodis, both of which were sent in fine copies by Bucer to John Cheke in 1550. The covering letter that accompanied these books survives today at Corpus Christi College, Cambridge, whilst the presentation copy of De regno Christi intended for King Edward VI is British Library, Royal MS. 8 B. VII. The circumstances surrounding these books, their production and transmission can be reconstructed in unusual and intriguing detail. This article presents several new and important discoveries, including the identification of the two presentation copies of Sturm’s De periodis mentioned by Bucer in his letter (today London, British Library, C.24.e.5 and Cambridge, Trinity College, II.12.21), as well as the tentative attribution of the binding of Royal MS. 8 B. VII to Bucer’s collaborator, the Strasbourg-based printer Remigius Guidon. An in-depth analysis of these artefacts and their codicological features confirms that TCC II.12.21 was intended for Edward VI, whereas BL C.24.e.5 can be identified, for the first time, as a book designed for and received by Princess Elizabeth. The dynamics governing the production and exchange of presentation copies between the Edwardian court and the Protestant reformers serve to paint a sharply focused picture of Bucer’s activities around 1550, that is, at a key moment of religious change in England

Rewriting the Gesta Normannorum ducum at Saint-Victor in the Fifteenth Century:Simon de Plumetot’s Brevis cronica compendiosa ducum Normannie

This article offers an analysis, edition, and translation of the Brevis cronica compendiosa ducum Normannie, a historiographical account of the dukes of Normandy and their deeds, written at the turn of the fifteenth century by the Norman jurist and man of letters, Simon de Plumetot (1371–1443). Having all but escaped the attention of modern scholars, this study is the first to examine and publish the Brevis cronica. It not only demonstrates that the work is of greater importance than its rather scrappy form might at first suggest, but it also looks to place the text within the broader context of Simon’s literary and bibliophilic practices, and to determine its raison d’être. In doing so, it argues that the Brevis cronica was perhaps created as part of a much larger historiographical project, namely an extended chronicle of Normandy, probably written in the vernacular, the text of which is now lost. By exploring these important issues, the article sheds new light on a wide range of topics, from early humanist book collecting to the writing of history in France in the later Middle Ages

Regionalizing rainfall at very high resolution over la Réunion island using a regional climate model.

23 pagesInternational audienceRegional climate models (RCMs) should be evaluated with respect to their ability to downscale large-scale climate information to the local scales, which are sometimes strongly modulated by surface conditions. This is the case for La Reunion (southwest Indian Ocean) because of its island context and its complex topography. Large-scale atmospheric configurations such as tropical cyclones (TCs) may have an amplifying effect on local rainfall patterns that only a very high-resolution RCM, forced by the large scales and resolving finescale processes, may simulate properly. This paper documents the capability of the Weather Research and Forecasting Model (WRF) RCM to regionalize rainfall variability at very high resolution (680 m) over La Reunion island for daily to seasonal time scales and year-to-year differences. Two contrasted wet seasons (November-April) are selected: 2000-01 (abnormally dry) and 2004-05 (abnormally wet). WRF rainfall is compared to a dense network of rain gauge records interpolated onto the WRF grid through the regression-kriging (RK) technique. RK avoids the point-to-grid comparison issue, but produces imperfect estimates due to sampling, so its quality also needs to be tested. Seasonal rainfall amounts and contrasts produced by WRF are fairly realistic. At intraseasonal and daily time scales, differences to RK are more sizable. These differences are not easy to interpret in sectors where the rain gauge network is less dense and the quality of RK more uncertain, as over the eastern slopes of Piton de la Fournaise volcano where WRF seems to simulate more realistic rainfall than RK. Finally, the heavy rainfall associated with TC Ando on 6 January 2001, is documented. WRF shows weak disagreements with RK, indicating its capability to regionalize rainfall during extreme events

(Re-)Framing Bede’s <i>Historia ecclesiastica </i>in twelfth-century Germany:John Rylands Library, MS Latin 182

This article offers the first comprehensive study of Manchester, John Rylands Library, MS Latin 182, a twelfth-century codex formerly belonging to (and possibly produced at) the Benedictine Abbey of (Mönchen-)Gladbach in Germany. I begin with a full codicological and palaeographical analysis of the entire manuscript, before moving on to a discussion of its contents. These include the Venerable Bede‘s Historia ecclesiastica gentis Anglorum and the Continuatio Bedae, as well as two hagiographical works copied at the end of the manuscript. I then propose a new possible context of reception for Bede‘s Historia ecclesiastica during the twelfth century, one that interlinked with the prevalent discourses on secular ecclesiastical lordship and monastic reform at Gladbach, as well as, perhaps, in Germany more widely. In doing so, I essentially argue for the possibility that the Gladbach scribes and their audiences may have used and understood the Historia ecclesiastica not only in the conventional context of history and historiography, but also (and perhaps equally important) as an example of the golden age of monasticism which during the later twelfth century was re-framed and re-contextualised as both a spiritual guide and a source of miracle stories.</jats:p