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Variations in southern African precipitation have a major impact on local communities, increasing climate‐related risks and affecting water and food security, as well as natural ecosystems. However, future changes in southern African precipitation are uncertain, with climate models showing a wide range of responses from near‐term projections (2020–2040) to the end of the 21st century (2080–2100). Here, we assess the uncertainty in southern African precipitation change using five Ocean‐Atmosphere General Circulation single model initial‐condition large ensembles (30–50 ensemble members) and four emissions scenarios. We show that the main source of uncertainty in 21st Century projections of southern African precipitation is the internal climate variability. In addition, we find that differences between ensemble members in simulating future changes in the location of the Angola Low explain a large proportion (∼60%) of the uncertainty in precipitation change. Together, the internal variations in the large‐scale circulation over the Pacific Ocean and the Angola Low explain ∼64% of the uncertainty in southern African precipitation change. We suggest that a better understanding of the future evolutions of the southern African precipitation may be achieved by understanding better the model's ability to simulate the Angola Low and its effects on precipitation. The variability of precipitation in southern Africa has a strong impact on local communities, rain‐fed agriculture, food security and water demand, hydropower production, lake levels, ecosystems, and wildlife. Above‐average rainfall increases the risk of flooding, while below‐average rainfall increases the risk of drought. However, future changes in precipitation in southern Africa are poorly understood. Here, we examine the potential sources of uncertainty in southern African precipitation change using five ocean‐atmosphere general circulation single‐model initial‐condition large ensembles and four emissions scenarios. We show that the main source of uncertainty is the simulation of internal climate variability throughout the 21st century. Among potential drivers, we show that the main driver of uncertainty in southern African precipitation change is the future change in the location of the Angola low. A future northward (southward) shift of the Angola Low is associated with a future decrease (increase) in southern African precipitation. We suggest that a better understanding of future changes in southern African precipitation could be achieved by better understanding the impact of internal climate variability on the Angola Low. Future changes in southern African precipitation are uncertainThe main source of uncertainty in simulating southern African precipitation change is internal climate variabilityFuture changes in southern African precipitation depend on internal variations in the meridional location of the Angola Low Future changes in southern African precipitation are uncertain The main source of uncertainty in simulating southern African precipitation change is internal climate variability Future changes in southern African precipitation depend on internal variations in the meridional location of the Angola Low

During atmospheric river (AR) landfalls on the Antarctic ice sheet, the high waviness of the circumpolar polar jet stream allows for subtropical air masses to be advected toward the Antarctic coastline. These rare but high‐impact AR events are highly consequential for the Antarctic mass balance; yet little is known about the various atmospheric dynamical components determining their life cycle. By using an AR detection algorithm to retrieve AR landfalls at Dumont d'Urville and non‐AR analogs based on 700 hPa geopotential height, we examined what makes AR landfalls unique and studied the complete life cycle of ARs reaching Dumont d'Urville. ARs form in the mid‐latitudes/subtropics in areas of high surface evaporation, likely in response to tropical deep convection anomalies. These convection anomalies likely lead to Rossby wave trains that help amplify the upper‐tropospheric flow pattern. As the AR approaches Antarctica, condensation of isentropically lifted moisture causes latent heat release that—in conjunction with poleward warm air advection—induces geopotential height rises and anticyclonic upper‐level potential vorticity tendencies downstream. As evidenced by a blocking index, these tendencies lead to enhanced ridging/blocking that persist beyond the AR landfall time, sustaining warm air advection onto the ice sheet. Finally, we demonstrate a connection between tropopause polar vortices and mid‐latitude cyclogenesis in an AR case study. Overall, the non‐AR analogs reveal that the amplified jet pattern observed during AR landfalls is a result of enhanced poleward moisture transport and associated diabatic heating which is likely impossible to replicate without strong moisture transport. When the polar jet stream that surrounds Antarctica is highly wavy, air masses from the subtropics that are warm and humid are often transported over the ice sheet in the form of atmospheric rivers (ARs). When ARs reach Antarctica, they often bring extreme weather conditions that have large consequences for ice sheet snowfall and surface melt. Here we studied the full life cycle of ARs that reached Dumont d'Urville in East Antarctica and compared these ARs against events with similar profiles of atmospheric circulation. ARs typically form in areas of unusually high surface evaporation and thunderstorm convection in the subtropics. This convection sends Rossby waves toward the Antarctic coastline which help make the polar jet wavier. The amplitude of the polar jet is further enhanced when the moisture that accompanies the ARs condenses over the cooler seas around Antarctica and creates large latent heating. The higher amplitude of the polar jet often results in atmospheric blocks that transport further warm, moist air over the ice sheet even after the AR has made landfall and dissipated. Therefore, extreme weather events over Antarctica like ARs are sensitive to climate changes far from the continent over the subtropical regions. Atmospheric rivers have lower‐latitude moisture sources than extratropical cyclones and are likely influenced by tropopause polar vorticesLarge latent heat release from atmospheric river related moisture transport leads to downstream anticyclonic potential vorticity tendenciesThe resultant diabatic heating helps maintain atmospheric blocking after an atmospheric river has dissipated Atmospheric rivers have lower‐latitude moisture sources than extratropical cyclones and are likely influenced by tropopause polar vortices Large latent heat release from atmospheric river related moisture transport leads to downstream anticyclonic potential vorticity tendencies The resultant diabatic heating helps maintain atmospheric blocking after an atmospheric river has dissipated

Abstract: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, 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.

This article is dedicated to Liesbeth van Houts, editor of the Gesta Normannorum ducum, generous mentor, colleague, and friend.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 cronicawas perhaps created as part of a much larger historiographical project, namely an extended chronicle of Normandy, 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.

The modulation of the rainfall diurnal cycle at intraseasonal and interannual time scales is examined using gridded rainfall data over Eastern Africa and the nearby Indian Ocean for the period 1998–2014. Our focus is on the October‐December season which is strongly impacted by both the Madden‐Julian Oscillation (MJO) and the Indian Ocean Dipole Mode (IODM). The effect of the MJO, which is not synchronized across the whole region, is mainly through changes in the amplitude of the diurnal cycle, especially an enhancement of the late afternoon peak in active phases of the MJO. The rainfall phase only shows minor variations between the active and quiescent phases of the MJO, except over the drier regions and the Indian Ocean where the overall diurnal rainfall signal is more uneven. The effect of the positive phase of the IODM (warm western Indian Ocean) on Eastern Africa rainfall is found at any time of the day, but the enhancement is more prominent during the wettest part of the day (generally the afternoon). Substantial changes in the diurnal phase of the rains are found in some land areas away from the coast or from mountain ranges, where the dominant afternoon peak during the negative IODM phase is replaced by a nighttime maximum during the positive phase. Cross‐sections and a cluster analysis of diurnal rainfall patterns over Kenya and southern Somalia suggest that this feature may be associated with the development of longer‐lived rainfall systems propagating inland from the coast during the IODM positive phase. Diurnal rainfall distribution over Eastern Africa and the nearby Indian Ocean is modulated at intraseasonal and interannual time scalesThe Madden‐Julian Oscillation mainly affects the diurnal cycle amplitude, especially by enhancing or weakening the late afternoon peakThe Indian Ocean Dipole Mode also mostly affects the amplitude, but notable changes occur in the phase of the rains over some land areas

Canicules et fortes chaleurs induisent un stress thermique potentiellement accru en milieu urbain. Nous examinons ici la combinaison de ces différents éléments à Dijon, à partir d’un réseau dense de stations avec des mesures horaires sur la période 2014-2021. Pour cela, nous mettons en œuvre une analyse (i) de la circulation atmosphérique synoptique et locale et (ii) des déterminants géophysiques (occupation du sol et topographie). Les cinq canicules détectées persistent 4 à 5 jours et sont associées à des situations de blocage atmosphérique de large échelle favorisant le développement d’inversions thermiques. Sur les 24 nuits étudiées : 60% sont caractérisées par un Îlot de Chaleur Urbain (ICU) excédant +3°C, une inversion thermique souvent supérieure à 0,5°C/100 m et un vent faible (<2 m/s); 30% par un ICU plafonnant à +2°C, un gradient adiabatique et un vent non négligeable (>2 m/s); 10% par un faible ICU, une faible inversion thermique et des conditions de vent variables. Des statistiques comparables sont obtenues par jours de fortes chaleurs (105 jours). Canicules et fortes chaleurs sont associées à deux structures contrastées en fonction des conditions de vent. Un vent non négligeable (>2 m/s) contribue à ventiler l’excès de chaleur de la ville et à limiter le contrôle de la topographie. En résultent des températures très homogènes sur l’ensemble de l’aire d’étude. Au contraire, un vent faible (<2 m/s) maximise le contrôle de l’occupation du sol et de la topographie sur la température de l’air. En résulte un excès de chaleur en ville. La plaine, à l’est, est relativement plus fraîche que le plateau à l’ouest, de même qu’un axe traversant l’agglomération le long du talweg et du cours d’eau (vallée de l’Ouche). Cet axe frais naturel limite l’ICU ou, a minima, favorise de relatifs Îlots de Fraîcheur Urbains nocturnes. Cette étude montre la pertinence de l’analyse combinée d’un réseau de mesures de la température de l’air, de la circulation atmosphérique et des descripteurs géophysiques pour mettre à jour les déterminants de la température de l’air et la spatialiser.

Future changes in Sahel precipitation are uncertain because of large differences among projections from various models. In order to explore this uncertainty, we use a storyline approach which seeks to identify alternative plausible evolutions of Sahel precipitation and their driving factors. By analyzing projections from the CMIP6 climate models, we show that changes in North Atlantic and in Euro‐Mediterranean temperatures explain up to 60% of the central Sahel precipitation change uncertainty. We then construct several storylines of Sahel precipitation change based on future plausible changes in North Atlantic and Euro‐Mediterranean temperatures. In one storyline, an amplified warming of both the North Atlantic and the Euro‐Mediterranean areas promotes a northward shift of the West African monsoon, increasing precipitation over the central Sahel, while, in the opposite storyline, a moderate warming in both regions is associated with a small change in precipitation over the central Sahel and a decrease in precipitation over the western Sahel, at the end of the 21st century. These results indicate that Sahel precipitation uncertainty will not be substantially reduced unless the uncertainty in the future warming of the North Atlantic and the Euro‐Mediterranean areas is constrained. Variations in the strength of the West African Monsoon (WAM) circulation have societal impacts on around 80 million people from Senegal to Chad. However, future projections of the WAM precipitation are uncertain for the end of the 21st century because of strong differences from one climate model to another. We show here that sources of uncertainty in Sahel precipitation depend on changes in North Atlantic and Euro‐Mediterranean temperature, relative to changes in global mean surface air temperature. We show that differences in how climate models simulate the future warming over the North Atlantic and Euro‐Mediterranean area explain a large proportion of the uncertainty in precipitation change over the central Sahel. We provide a method that could be helpful at selecting models for impact studies, based on their sensitivity to climate change over the North Atlantic ocean and Mediterranean Sea. Future changes in Sahel precipitation are uncertainChanges in North Atlantic and Euro‐Mediterranean temperatures explain up to 60% of the Sahel precipitation change uncertaintyUncertainty in changes in Sahel precipitation is associated with uncertainty in the future northward shift of the Saharan heat low Future changes in Sahel precipitation are uncertain Changes in North Atlantic and Euro‐Mediterranean temperatures explain up to 60% of the Sahel precipitation change uncertainty Uncertainty in changes in Sahel precipitation is associated with uncertainty in the future northward shift of the Saharan heat low

Here, we analyze the inter‐relationships between weather types (WTs) and atmospheric rivers (ARs) around Aotearoa New Zealand (ANZ), their respective properties, as well as their combined and separate influence on daily precipitation amounts and extremes. Results show that ARs are often associated with 3–4 WTs, but these WTs change depending on the regions where ARs landfall. The WTs most frequently associated with ARs generally correspond to those favoring anomalously strong westerly wind in the mid‐latitudes, especially for southern regions of ANZ, or northwesterly anomalies favoring moisture export from the lower latitudes, especially for the northern regions. WTs and ARs show strong within‐type and inter‐event diversity. The synoptic patterns of the WTs significantly differ when they are associated with AR occurrences, with atmospheric centers of actions being shifted so that moisture fluxes toward ANZ are enhanced. The location, angle, and persistence of ARs appear strongly driven by the synoptic configurations of the WTs. Although total moisture transport shows weaker WT‐dependency, it appears strongly related to zonal wind speed to the south of ANZ, or the moisture content of the air mass to the north. Finally, WT influence on daily precipitation may completely change depending on their association, or lack thereof, with AR events. WTs traditionally considered as favorable to wet conditions may conceal daily precipitation extremes occurring during AR days, and anomalously dry days or near‐climatological conditions during non‐AR days. We analyze here how atmospheric rivers (ARs) relate to weather types (WTs), using the case study of Aotearoa New Zealand (ANZ). We show that, for each region of ANZ, ARs tend to occur during different WTs. Generally, for a given region, most ARs form during 3 or 4 main WTs, and these dominant WTs differ from one region to another. These WTs also show different patterns when they are associated with ARs, compared to other days. AR days have atmospheric configurations that are more efficient to direct moisture fluxes toward the coasts of ANZ. Combining both view of regional climate variability is important to understand the drivers of extreme precipitation events. Weather types (WTs) are major drivers of atmospheric rivers (ARs) (frequency, angle, moisture transport direction, and landfalling region)ARs explain part of within‐type diversity (circulation and rainfall anomalies)Combined or separate effects of WTs and ARs strongly vary from one region of Aotearoa New Zealand to another Weather types (WTs) are major drivers of atmospheric rivers (ARs) (frequency, angle, moisture transport direction, and landfalling region) ARs explain part of within‐type diversity (circulation and rainfall anomalies) Combined or separate effects of WTs and ARs strongly vary from one region of Aotearoa New Zealand to another

This article provides the first detailed study of two medieval liturgical manuscripts from the Benedictine Abbey of Lambach, Upper Austria, kept today in the monastic Library and Archives of Downside Abbey in Stratton-on-the-Fosse, Somerset, UK. The new codicological, palaeographical and historical evidence presented in this study shows that both these manuscripts played a central part in the monastery’s liturgical life and routine during the later 12th century. The first part of the article provides a full codicological and palaeographical analysis of the two manuscripts, the first to appear in published form, while the second part offers a wider thematic study that contextualises the two codices and their contents within Lambach’s medieval liturgical and communal culture.

The abbey of Saint-Étienne de Caen was founded by Duke William II of Normandy in or around 1063. Within a few years of its festive dedication, it was endowed with extensive lands and churches, many of which were located in the ecclesiastical province of Bayeux. These grants played a key role in shaping Saint-Étienne’s relationship with one of the region’s foremost spiritual and political authorities: the cathedral chapter of Bayeux. This article engages with a sizeable corpus of archival sources (many of which are unpublished) in scrutinizing a particularly important rivalry that emerged between the monks and the cathedral canons during the later eleventh and twelfth centuries, involving not only their respective abbots and deacons, but also the bishop of Bayeux, the archbishop of Rouen, the pope and the king of England. Particular attention will be paid to the symbolic dimension of this rivalry and the ways in which conflicts of authority were turned into political ritual and public display.

This article investigates the sources of prosopographical information used by Robert of Torigni, a twelfth-century Benedictine monk and historian at the Norman abbey of Le Bec (1128-54) and later abbot of Mont-Saint-Michel (1154-86). Robert is known to have composed a large number of detailed genealogical narratives, which he inserted into his redaction of William of Jumièges’ Gesta Normannorum ducum, as well as into his continuation of Sigebert of Gembloux’s ‘World History’, known as the Chronica. Much work has been done in an attempt to verify (or contest) the accuracy of Robert’s genealogies, but little investigation has been undertaken of the possible templates used for their compilation. This article will redress this imbalance in two steps. First, it will offer a detailed analysis of Le Bec’s twelfth-century library, discussing both extant and lost material and comparing Le Bec to other contemporary Norman and Anglo-Norman monasteries (particularly Durham), in order to theorise as to the types of sources to which Robert might have had access at his home monastery. This will lay the groundwork for the second part of the argument, which will employ later medieval and early modern copies of lost original documents (such as annals, calendars, necrologies and lists of monks and benefactors) as a means of reconstructing Robert’s primary sources for the writing of family history and genealogy at Le Bec during the twelfth century. My main focus will be on the Clare family, whose members figure prominently in both Robert’s work and the surviving sources from Le Bec.

Depuis le début des années 2000, le « climato-pessimisme » est devenu un objet cinématographique de plus en plus prisé par les spectateurs, traduisant certaines angoisses de la société actuelle. Ainsi, les films catastrophe, dystopiques et post-apocalyptiques ne sont pas que de simples divertissements et manifestations de certains effets de mode, ils sont aussi le reflet des avancées scientifiques de leur temps. Dans cet article, 55 films ont été sélectionnés en fonction des différentes représentations du climat et des conditions météorologiques qu’ils proposent. Le climat est présenté et perçu très différemment d’un film à un autre. Bien que le changement climatique soit souvent devenu un contexte privilégié dans les scénarios des films récents, il n’est pas forcément mis en avant par rapport à d’autres menaces de grande ampleur auxquelles l’humanité pourrait faire face. Des conditions météo-climatiques hostiles confèrent en effet une ambiance adéquate qui s’ajoute aux multiples tourments subis par les protagonistes. L’analyse des phénomènes météo-climatiques fait ressortir certaines tentatives de se référer à des travaux et résultats scientifiques reconnus, si possible en lien avec des phénomènes aux impacts aussi spectaculaires que catastrophiques, et permet ainsi d’adresser des messages d’alerte et de mise en garde aux spectateurs. De nombreux films montrent aussi une certaine propension à plonger la Terre dans l’aridité. Au-delà de la pertinence scientifique plus ou moins valide d’une possible aridification selon le scénario concerné, l’esthétique des environnements désertiques (villes ensablées, tempêtes de poussière) est sans doute un effet délibérément recherché dans cette catégorie de films.

In 1001 Duke Richard II of Normandy appointed William of Dijon as the first abbot of La Trinité de Fécamp. Together with his patron, William initiated a programme of monastic reform which scholarship has long seen as a deliberate imitation of Cluniac custom. This equation has been based on a corpus of early Norman charters that are widely held to have exempted Fécamp from Rouen’s episcopal authority as early as 1006, explicitly evoking Cluny in an attempt to abolish the bishop’s rights in the election and blessing of abbots. Following a comprehensive reassessment of the historical and diplomatic evidence, this article argues that Cluny did not become a model for Fécamp before the second half of the eleventh century. It questions notions of continuity by demonstrating that both the charters and the traditions to which they pertain are in fact later eleventh-century inventions, which medieval forgers and modern readers alike have projected back onto earlier periods.

Two component mixtures of dinitrile functionalized disiloxanes and ethylene carbonate were investigated as new solvent composition for liquid electrolytes in lithium-ion half-cells. Their thermal and chemical stability offer an enhanced safety due to the substitution of the usually used volatile noncyclic carbonates of standard electrolyte compositions by 1,3-Bis(3-cyanopropyl)tetramethyldisiloxane which was tested in a 1:1 mixture with ethylene carbonate (denoted as dinitrile/EC). A wide electrochemical window up to 5.4 V vs. Li/Li+ on Pt electrode was obtained using LiClO4 as lithium salt. The dinitrile/EC electrolyte shows ionic conductivities reaching 1 mS*cm[?]1 and viscosities of 13 mPa*s at 30degC. Half-cell tests using graphite and LFP electrodes yielded high capacity retentions of 90% of the initial capacity after more than 500 cycles.

Abstract:This article investigates a specific twelfth-century hand that occurs in a group of manuscripts connected to the Norman abbey of Mont-Saint-Michel and identifies it as the hand of Robert of Torigni, the famous Anglo-Norman historian who became abbot of that monastery in 1154. The manuscripts used as evidence all contain corrections and interlinear glosses in what I contend constitutes Robert’s own hand, and have neither been studied comparatively nor had their relationships scrutinized. Indeed, scholarship to date has actually argued for different examples of handwriting altogether as belonging to Robert and has not inquired as to whether the glosses and annotations contained within the codices discussed here could be indicative of Robert’s scribal activity in the scriptorium of Mont-Saint-Michel during the period of his abbacy (1154–86). This article, therefore, seeks to challenge the prevailing notions concerning Robert’s characteristic handwriting, both in terms of its supposed shape and character, and with regard to the manuscripts in which it is thought to survive. This fundamental reassessment of previous scholarship will be achieved by combining, for the first time, a comprehensive paleographical analysis of the manuscripts with a discussion of their broader historical and institutional contexts. Furthermore, and perhaps more significantly, in identifying Robert’s hand and the contexts in which it survives, this article aims to enhance our knowledge concerning the person behind the script. It will present new and important insights into Robert’s activities as head of his monastic community, as well as into his methods as a monastic historian who, as will be shown, was intimately involved in the processes of manuscript production at Mont-Saint-Michel during the second half of the twelfth century. Ultimately, this article argues that Robert, despite being the author and intellectual architect of complex and influential historical works, had in fact very little training as a book scribe, which is evidenced by his handwriting.

This article investigates a specific twelfth-century hand that occurs in a group of manuscripts connected to the Norman abbey of Mont-Saint-Michel and identifies it as the hand of Robert of Torigni, the famous Anglo-Norman historian who became abbot of that monastery in 1154. The manuscripts used as evidence all contain corrections and interlinear glosses in what I contend constitutes Robert's own hand, and have neither been studied comparatively nor had their relationships scrutinized. Indeed, scholarship to date has actually argued for different examples of handwriting altogether as belonging to Robert and has not inquired as to whether the glosses and annotations contained within the codices discussed here could be indicative of Robert's scribal activity in the scriptorium of Mont-Saint-Michel during the period of his abbacy (1154–86). This article, therefore, seeks to challenge the prevailing notions concerning Robert's characteristic handwriting, both in terms of its supposed shape and character, and with regard to the manuscripts in which it is thought to survive. This fundamental reassessment of previous scholarship will be achieved by combining, for the first time, a comprehensive paleographical analysis of the manuscripts with a discussion of their broader historical and institutional contexts. Furthermore, and perhaps more significantly, in identifying Robert's hand and the contexts in which it survives, this article aims to enhance our knowledge concerning the person behind the script. It will present new and important insights into Robert's activities as head of his monastic community, as well as into his methods as a monastic historian who, as will be shown, was intimately involved in the processes of manuscript production at Mont-Saint-Michel during the second half of the twelfth century. Ultimately, this article argues that Robert, despite being the author and intellectual architect of complex and influential historical works, had in fact very little training as a book scribe, which is evidenced by his handwriting.

Here, we define weather regimes in the East Antarctica—Southern Ocean sector based on daily anomalies of 700 hPa geopotential height derived from ERA5 reanalysis during 1979–2018. Most regimes and their preferred transitions depict synoptic‐scale disturbances propagating eastwards off the Antarctic coastline. While regime sequences are generally short, their interannual variability is strongly driven by the polarity of the Southern Annular Mode (SAM). Regime occurrences are then intersected with atmospheric rivers (ARs) detected over the same region and period. ARs are equiprobable throughout the year, but clearly concentrate during regimes associated with a strong atmospheric ridges/blockings on the eastern part of the domain, which act to channel meridional advection of heat and moisture from the lower latitudes towards Antarctica. Both regimes and ARs significantly shape climate variability in Antarctica. Regimes favorable to AR occurrences are associated with anomalously warm and humid conditions in coastal Antarctica and, to a lesser extent, the hinterland parts of the Antarctic plateau. These anomalies are strongly enhanced during AR events, with warmer anomalies and dramatically amplified snowfall amounts. Large‐scale conditions favoring AR development are finally explored. They show weak dependency to the SAM, but particularly strong atmospheric ridges/blockings over the Southern Ocean appear as the most favorable pattern, in which ARs can be embedded, and to which they contribute. Atmospheric rivers (ARs) reaching East Antarctica show strong association with synoptic weather regimesARs enhance the positive temperature and snowfall anomalies associated with the regimesARs occur when the synoptic configuration is anomalously strong over the Southern Ocean Atmospheric rivers (ARs) reaching East Antarctica show strong association with synoptic weather regimes ARs enhance the positive temperature and snowfall anomalies associated with the regimes ARs occur when the synoptic configuration is anomalously strong over the Southern Ocean

The West African Monsoon (WAM) influence on the interannual variability of the summer atmospheric circulation over North Atlantic and Europe is investigated over the period 1971–2000. A set of sensitivity experiments performed through the Arpege‐Climat Atmospheric General Circulation Model is analyzed, using the so‐called “grid‐point nudging” technique, where the simulated atmospheric fields in the WAM region are relaxed towards the ERA40 reanalysis. Observations confirm that a sizable part of the Euro‐Atlantic circulation variability is related to the WAM, with anomalies of reinforced convection in the Sudan‐Sahel region associated with positive North Atlantic Oscillation (NAO) phases and subsidence over eastern Mediterranean. The nudged simulations highlights the role of the WAM in driving the mid‐latitude circulation. A strong monsoon is related to high‐pressure anomalies over the Azores and positive NAO phases. The role of the WAM in driving the Euro‐Atlantic circulation is highlightedStrong WAM is related to high‐pressure anomalies over Azores and positive NAOThe nudging replaces the NAO centers of action close to their observed locations