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Article

Jin-Song von Storch

The energetics considerations based on Lorenz’s available potential energy A focus on identification and quantification of processes capable of converting external energy sources into the kinetic energy of atmospheric and oceanic general circulations. Generally, these considerations consist of: (a) identifying the relevant energy compartments from which energy can be converted against friction to kinetic energy of motions of interests; (b) formulating for these energy compartments budget equations that describe all possible energy pathways; and (c) identifying the dominant energy pathways using realistic data. In order to obtain a more detailed description of energy pathways, a partitioning of motions, for example, into a “mean” and an “eddy” component, or into a diabatic and an adiabatic component, is used. Since the budget equations do not always suggest the relative importance of all possible pathways, often not even the directions, data that describe the atmospheric and the oceanic state in a sufficiently accurate manner are needed for evaluating the energy pathways. Apart from the complication due to different expressions of A , ranging from the original definition by Lorenz in 1955 to its approximations and to more generally defined forms, one has to balance the complexity of the respective budget equations that allows the evaluation of more possible energy pathways, with the quality of data available that allows sufficiently accurate estimates of energy pathways. With regard to the atmosphere, our knowledge, as inferred from the four-box Lorenz energy cycle, has consolidated in the last two decades, by, among other means, using data assimilation products obtained by combining observations with realistic atmospheric general circulation models (AGCMs). The eddy kinetic energy, amounting to slightly less than 50% of the total kinetic energy, is supported against friction through a baroclinic pathway “fueled” by the latitudinally dependent diabatic heating. The mean kinetic energy is supported against friction by converting eddy kinetic energy via inverse cascades. For the ocean, our knowledge is still emerging. The description through the four-box Lorenz energy cycle is approximative and was only estimated from a simulation of a 0 . 1 ° oceanic general circulation models (OGCM) realistically forced at the sea surface, rather than from a data assimilation product. The estimates obtained so far suggest that the oceanic eddy kinetic energy, amounting almost 75% of the total oceanic kinetic energy, is supported against friction through a baroclinic pathway similar to that in the atmosphere. However, the oceanic baroclinic pathway is “fueled” to a considerable extent by converting mean kinetic energy supported by winds into mean available potential energy. Winds are also the direct source of the kinetic energy of the mean circulation, without involving noticeable inverse cascades from transients, at least not for the ocean as a whole. The energetics of oceanic general circulation can also be examined by separating diabatic from adiabatic processes. Such a consideration is thought to be more appropriate for understanding the energetics of the oceanic meridional overturning circulation (MOC), since this circulation is sensitive to density changes induced by diabatic mixing. Further work is needed to quantify the respective energy pathways using realistic data.

Article

Pierre Camberlin

Eastern Africa, classically presented as a major dry climate anomaly region in the otherwise wet equatorial belt, is a transition zone between the monsoon domains of West Africa and the Indian Ocean. Its complex terrain, unequaled in the rest of Africa, results in a huge diversity of climatic conditions that steer a wide range of vegetation landscapes, biodiversity and human occupations. Meridional rainfall gradients dominate in the west along the Nile valley and its surroundings, where a single boreal summer peak is mostly observed. Bimodal regimes (generally peaking in April and November) prevail in the east, gradually shifting to a single austral summer peak to the south. The swift seasonal shift of the Intertropical Convergence Zone and its replacement in January–February and June–September by strong meridional, generally diverging low-level winds (e.g., the Somali Jet), account for the low rainfall. These large-scale flows interact with topography and lakes, which have their own local circulation in the form of mountain and lake breezes. This results in complex rainfall patterns, with a strong diurnal component, and a frequent asymmetry in the rainfall distribution with respect to the major relief features. Whereas highly organized rain-producing systems are uncommon, convection is partly modulated at intra-seasonal (about 30–60-day) timescales. Interannual variability shows a fair level of spatial coherence in the region, at least in July–September in the west (Ethiopia and Nile Valley) and October–December in the east along the Indian Ocean. This is associated with a strong forcing from sea-surface temperatures in the Pacific and Indian Oceans, and to a lesser extent the Atlantic Ocean. As a result, Eastern Africa shows some of the largest interannual rainfall variations in the world. Some decadal-scale variations are also found, including a drying trend of the March–May rainy season since the 1980s in the eastern part of the region. Eastern Africa overall mean temperature increased by 0.7 to 1 °C from 1973 to 2013, depending on the season. The strong, sometimes non-linear altitudinal gradients of temperature and moisture regimes, also contribute to the climate diversity of Eastern Africa.

Article

“Buddhist medicine” is a convenient term commonly used to refer to the many diverse ideas and practices concerning illness and healing that have emerged in Buddhist contexts, or that have been embraced and carried by that religion as it has spread throughout Asia and beyond. Interest in exploring the relationship between mind and body, understanding the nature of mental and physical suffering, and overcoming the discomforts of illness goes back to the very origins of Buddhism. Throughout history, Buddhism has been one of the most important contexts for the cross-cultural exchange of diverse currents of medicine. Medicine associated with and carried by Buddhism formed the basis for a number of local healing traditions that are still widely practiced in much of East, Southeast, and Central Asia. Despite the fact that there are numerous similarities among these regional forms, however, Buddhist medicine was never a cohesive or fixed system. Rather, it should be thought of as a dynamic, living tradition with a few core features and much local variation. Local traditions of Buddhist medicine represent unique hybrid combinations of cross-culturally transmitted and indigenous knowledge. In the modern period, such traditions were thoroughly transformed by interactions with Western colonialism, scientific ideas, and new biomedical technologies. In recent decades, traditional, modern, and hybrid forms of medicine continue to be circulated by transnational Buddhist organizations and through the global popularization of Buddhist-inspired therapeutic meditation protocols. Consequently, Buddhism continues today to be an important catalyst for cross-cultural medical exchange, and it continues to exert a significant influence on healthcare practices worldwide.

Article

Carl Wunsch

Oceanic mixing is one of the major determinants of the ocean circulation and its climatological influences. Existing distributions of mixing properties determine the rates of storage and redistribution within the climate system of fundamental scalar tracers including heat, fresh water, oxygen, carbon, and others. Observations have overturned earlier concepts that mixing rates might be approximately uniform throughout the ocean volume, with profound implications for determining the circulation and its properties. Inferences about past and potential future oceanic circulations and the resulting climate influence require determination of changed energy inputs and the expected consequent adjustment of mixing processes and their influence.

Article

Stefano Tibaldi and Franco Molteni

The atmospheric circulation in the mid-latitudes of both hemispheres is usually dominated by westerly winds and by planetary-scale and shorter-scale synoptic waves, moving mostly from west to east. A remarkable and frequent exception to this “usual” behavior is atmospheric blocking. Blocking occurs when the usual zonal flow is hindered by the establishment of a large-amplitude, quasi-stationary, high-pressure meridional circulation structure which “blocks” the flow of the westerlies and the progression of the atmospheric waves and disturbances embedded in them. Such blocking structures can have lifetimes varying from a few days to several weeks in the most extreme cases. Their presence can strongly affect the weather of large portions of the mid-latitudes, leading to the establishment of anomalous meteorological conditions. These can take the form of strong precipitation episodes or persistent anticyclonic regimes, leading in turn to floods, extreme cold spells, heat waves, or short-lived droughts. Even air quality can be strongly influenced by the establishment of atmospheric blocking, with episodes of high concentrations of low-level ozone in summer and of particulate matter and other air pollutants in winter, particularly in highly populated urban areas. Atmospheric blocking has the tendency to occur more often in winter and in certain longitudinal quadrants, notably the Euro-Atlantic and the Pacific sectors of the Northern Hemisphere. In the Southern Hemisphere, blocking episodes are generally less frequent, and the longitudinal localization is less pronounced than in the Northern Hemisphere. Blocking has aroused the interest of atmospheric scientists since the middle of the last century, with the pioneering observational works of Berggren, Bolin, Rossby, and Rex, and has become the subject of innumerable observational and theoretical studies. The purpose of such studies was originally to find a commonly accepted structural and phenomenological definition of atmospheric blocking. The investigations went on to study blocking climatology in terms of the geographical distribution of its frequency of occurrence and the associated seasonal and inter-annual variability. Well into the second half of the 20th century, a large number of theoretical dynamic works on blocking formation and maintenance started appearing in the literature. Such theoretical studies explored a wide range of possible dynamic mechanisms, including large-amplitude planetary-scale wave dynamics, including Rossby wave breaking, multiple equilibria circulation regimes, large-scale forcing of anticyclones by synoptic-scale eddies, finite-amplitude non-linear instability theory, and influence of sea surface temperature anomalies, to name but a few. However, to date no unique theoretical model of atmospheric blocking has been formulated that can account for all of its observational characteristics. When numerical, global short- and medium-range weather predictions started being produced operationally, and with the establishment, in the late 1970s and early 1980s, of the European Centre for Medium-Range Weather Forecasts, it quickly became of relevance to assess the capability of numerical models to predict blocking with the correct space-time characteristics (e.g., location, time of onset, life span, and decay). Early studies showed that models had difficulties in correctly representing blocking as well as in connection with their large systematic (mean) errors. Despite enormous improvements in the ability of numerical models to represent atmospheric dynamics, blocking remains a challenge for global weather prediction and climate simulation models. Such modeling deficiencies have negative consequences not only for our ability to represent the observed climate but also for the possibility of producing high-quality seasonal-to-decadal predictions. For such predictions, representing the correct space-time statistics of blocking occurrence is, especially for certain geographical areas, extremely important.

Article

Joshua A. Braun

Media distribution plays a key role in defining publics by determining which groups are able to access and share news. Put more broadly, decisions about how content circulates, whether they are made by corporations, platforms, street vendors, or file sharers, are central to the question of who has access to cultural resources and on what terms. This is significant for scholars of journalism insofar as a central concern of journalism studies is the role that news media play in public life. As media distribution has become increasingly dependent on digital intermediaries like search engines and social media, responsibility for media circulation has become an increasingly significant aspect of news work, shifting journalistic routines in the process. Though journalism studies researchers have typically paid less attention to distribution than to news production, news content, and audience reception, the disruptive changes wrought by the widespread adoption of digital media have begun to inspire renewed interest in distribution across media industry studies. And while various industries and regulatory regimes define distribution differently, it is important for scholarship on distribution to forge its own conception of the subject matter, both to avoid industry capture and to grapple with a changing media landscape in which formerly distinct professional boundaries between distribution and other media practices like production and marketing are rapidly blurring and shifting. A variety of scholars have argued that news distribution plays an important role in creating the imaginaries that sustain public life by enabling the conceit that media are addressed to the same audience over an extended period of time. It is true, too, that distribution networks can sow social divisions by extending the reach of messages and images beyond their intended contexts. The impact of the Internet on these dynamics has drawn a great deal of attention. Distribution platforms—even digital ones—should also be understood as having material underpinnings that can constrain their form and functionality, and arguably favor particular organizational forms. The resulting dynamics can dramatically impact news providers’ access to distribution networks and, by extension, audiences. This is true for physical distribution networks and also, mutatis mutandis, in online space, where news providers have become highly dependent on a small set of companies—Google, Facebook, and their ilk—for access to audiences. At the same time, many media organizations pay substantial amounts to vendors for access to white-label technologies and infrastructures to maintain their own distribution channels. The changing distribution landscape has led to changes in production dynamics at news organizations. In particular, the online advertising industry has now built its own distribution systems for ads, fundamentally changing the relationship between advertisers and the commercial news organizations on which they once relied for access to consumers. This, in turn, has led to changes in editorial logics at many news organizations aimed at preserving rapidly diminishing advertising revenues. Simultaneously, news distribution has become an increasing part of the work that goes on in news rooms, as optimizing the news for circulation via search and social media has become an editorial responsibility. These changes across media industries have generated a surge of interest in media distribution within academia.

Article

The Bay of Bengal has had long history of commercial and cultural circulation across its maritime space, a lesser-studied region in the emerging discourse of Indian Ocean Studies, and extended much beyond, in both eastern and western directions. However, this maritime space has conventionally been regarded as separating contours of peoples, cultures, and economies, particularly in the realm of area studies which has been deeply embedded in academic scholarship as well as political discourses. On the contrary, the region presents us with fascinating stories of integration through family trees, kinship networks, family firms, financial exchanges, intra-community and inter-ethnic bonding, and other facets of circular movements around the Bay. The political and economic narrative of Asia transformed into one of Western colonial dominance in the 19th century, a process that had begun about almost two centuries earlier. The British emerged as the most powerful of the Western powers in this space having gained strong political footing in India, their most prized possession in the East. The long years were marked by consolidation of their political conquests and economic prowess not only in the Indian subcontinent but also in and around the Bay of Bengal region. The technological innovations and inventions further facilitated their economic aspirations. The 20th century brought about different kind of changes. The ideal of laissez-faire along with the geopolitical discourse on rising maritime powers unleashed a new direction of policies, collaboration, conflicts, and negotiations. An important feature of the century was the dynamic rise of the ideology of nationalism, which worked differently in Europe and Asia. While it led to the world wars in Europe, for Asian powers, it opened doors of opportunity to break the fetters of several years of colonial domination. In the framework of a narrative of subjugation and domination, a macro-view of the Bay brings forth several circuits of circulation in the maritime space. While some of these circuits had been visible and dominant, others existed on the margins, connecting to the larger circuits obliviously, or existing in independent and almost invisible circulatory loops that did not find any place in Western historiography. This article attempts to provide a broad overview of different circulatory movements under four subthemes—acquisition and development of port cities that facilitated the circulatory process, merchants, banians, and capitalists—as both visible and also invisible actors of circulation in the Bay. It also discusses communities that were displaced, integrated, or acculturated around the rim of the Bay, and intellectual exchanges that motivated, influenced, and incorporated participation of a large number of people all over Asia. There is a focus on the mobile Indian communities in particular, both voluntary and involuntary migrants who were the dominant participants in the colonial economic narrative on both sides of the Bay. The legacy of these long years of exchanges and interactions has often been undermined in the postcolonial nation state centric discourses and needs to be revisited with a fresh perspective in view of the increasing geopolitical significance of the Bay in the 21st century.

Article

Translation is a social activity that fulfills other functions than mere communication: political, economic and cultural. Thus translation can be used as a political weapon to export or import texts conveying an ideological message, such as socialist realism. As evidenced by the promotion of world bestsellers, translation may in other cases serve economic interests. Literary translations also serve cultural purposes, such as the building of collective (national, social, gendered) identities, the representations of other cultures, or the subversion of the dominant norms in a literary field (as defined by Pierre Bourdieu), which can be illustrated by the reception and uses of William Faulkner’s novels in France in the 1930s (namely by Jean-Paul Sartre). The study of translation has become a research field called “Translation Studies,” which underwent a “sociological turn” at the beginning of the 21st century, and was also renewed at the same time by the rise of “world literature” studies in comparative literature. While translation studies are interested in norms of translation (as defined by Gideon Toury), which may vary across cultures, especially between domesticating and foreignizing strategies, the sociology of translation and of (world) literature asks how literary texts circulate across cultures: who are the mediators? Why do they select certain texts and not others? What obstacles stand in the way of the transfer process? How are translations used as weapons in cultural struggles? The circulation of texts in translation can be studied through a quantitative analysis of flows of translation (across languages, countries, publishing houses) and through qualitative methods: interviews with specialized intermediaries and cultural mediators (publishers, translators, state representatives, literary critics), ethnographic observation (of book fairs, literature festivals), documentary sources (critical reception), archives (of publishers), and text analysis. However, internal (text analysis) and external (sociological) approaches still wait to be fully connected.

Article

Robert Hariman

The concept of public culture refers most broadly to the dynamic negotiation of beliefs, values, and attitudes regarding collective association through media and other social practices that are defined by norms of open access and voluntary response. The concept is a recent innovation and applies primarily to modern societies, where public culture is the envelope of communication practices within which public opinion is formed; those practices can include news, entertainment, the arts, advertising, social media, and many other means for representing and judging any individual, institution, or custom having collective significance. The term “public” emphasizes relatively unrestricted communication across civil society regarding governance and other matters affecting the general welfare. The term “culture” emphasizes that public opinion depends on contextual factors that emerge through multiple media and embodied responsiveness. These considerations provide a basis for analysis of distinctively modern relationships across civil society, media technologies, and political action in a global context.

Article

Print culture in imperial China spans over twelve hundred years, from the late 7th century ce to the end of the Qing Dynasty in 1911. During this long period, mechanical reproduction of texts and image meant primarily woodblock printing (xylography), and, to a lesser extent, typography, using movable types made of wood, metal, and ceramics. Xylography was first used for religious purposes, such as prayer sheets and scriptures, but by the late 8th century, nonreligious imprints for daily use were produced. Only in the mid-10th century, however, did the state and the literati elite begin to produce and disseminate many nonreligious works in print. Thus, the dramatic growth in the number and diversity of imprints produced by government, private, religious, and commercial publishers took off in the Song Dynasty (960–1279), due in great part to the state’s efforts to compile and publish many works. One may argue, however, that not until the Ming Dynasty (1368–1644) would print culture be sufficiently widespread to be in ascendance, as evidenced by the great variety of works, the evolving page designs, and the changing attitudes of readers toward imprints. By the mid Qing Dynasty (1644–1911), printing had spread throughout the country into remote regions and throughout all levels of society. Changes in publishing culture from the 19th century onward were spurred by the adoption of new print technologies from the West, such as lithography and movable-type letterpress, which allowed for faster publication of far greater press runs, even as the traditional printing technologies continued to be used. Finally, it is important to note that a thriving manuscript culture continued to coexist with print until at least the late 19th century. The parting of the ways between print and manuscript became lasting only with the dominance of modern print technologies in the 20th century.

Article

Aderanti Adepoju

Intraregional migration of cross-border workers, unskilled and temporary contract workers, undocumented migrants, highly skilled professionals, and refugees characterize the migration landscape in Africa and is reflected in distinctive and changing configurations in the different subregions: labor migration in the west and central areas, movement of refugees in the eastern and southern areas, and migration of skilled professionals from west and east to southern Africa. Migrants and refugees in Africa share a number of common features: both are caused in large part by a set of interrelated factors—conflicts, underdevelopment, poor governance, and economic and social deprivation—and movements are confined largely to the continent. Youth unemployment, a major trigger for irregular migration, together with emigration of skilled professionals, pose serious challenges for many countries; remittances from the diaspora, though a lifeline for poor families left behind, do not compensate for the loss of skills. The refugee situation is highly dynamic and fluid. The sheer numbers of refugees in Africa, their composition, and the challenges they face and the limited success obtained thus far in the search for a permanent solution require sustained efforts in what is regarded an African problem requiring essentially an African solution.

Article

Rosemary J. Coombe and Susannah Chapman

Ethnographic research into intellectual property (IP) gained traction in the mid-1990s. During this period international trade agreements mandated that all states introduce minimum IP protections, property rights in intangible goods were expanded to encompass new subject areas, international Indigenous Peoples’ human rights were being negotiated, and protecting biodiversity became a global policy concern. Anthropologists considered IP extension in terms of the processes of commodification the law enabled, the cultural incommensurability of the law’s presuppositions in various societies, the implications of these rights for disciplinary research and publication ethics, and the modes of subjectification and territorialization that the enforcement of such laws engendered. Recognizing that IP clearly constrains and shapes the circulation of goods through the privatization of significant resources, critical anthropological examinations of Western liberal legal binary distinctions between public and private goods also revealed the forms of dispossession enabled by presuming a singular cultural commons. Anthropologists showed the diversity of publics constituted through authorized and unauthorized reproduction and circulation of cultural goods, exploring the management of intangible cultural goods in a variety of moral economies as well as the construction and translation of tradition in new policy arenas. The intersection of IP and human rights also prompted greater disciplinary reflexivity with respect to research ethics and publication practices. Analyzing how IP protections are legitimated and the activities that their enforcement delegitimizes, ethnography illustrated how the law creates privileged and abject subjectivities, reconfigures affective relationships between people and places, and produces zones of policing and discipline in processes of territorialization.

Article

Fred Kucharski and Muhammad Adnan Abid

The interannual variability of Indian summer monsoon is probably one of the most intensively studied phenomena in the research area of climate variability. This is because even relatively small variations of about 10% to 20% from the mean rainfall may have dramatic consequences for regional agricultural production. Forecasting such variations months in advance could help agricultural planning substantially. Unfortunately, a perfect forecast of Indian monsoon variations, like any other regional climate variations, is impossible in a long-term prediction (that is, more than 2 weeks or so in advance). The reason is that part of the atmospheric variations influencing the monsoon have an inherent predictability limit of about 2 weeks. Therefore, such predictions will always be probabilistic, and only likelihoods of droughts, excessive rains, or normal conditions may be provided. However, even such probabilistic information may still be useful for agricultural planning. In research regarding interannual Indian monsoon rainfall variations, the main focus is therefore to identify the remaining predictable component and to estimate what fraction of the total variation this component accounts for. It turns out that slowly varying (with respect to atmospheric intrinsic variability) sea-surface temperatures (SSTs) provide the dominant part of the predictable component of Indian monsoon variability. Of the predictable part arising from SSTs, it is the El Niño Southern Oscillation (ENSO) that provides the main part. This is not to say that other forcings may be neglected. Other forcings that have been identified are, for example, SST patterns in the Indian Ocean, Atlantic Ocean, and parts of the Pacific Ocean different from the traditional ENSO region, and springtime snow depth in the Himalayas, as well as aerosols. These other forcings may interact constructively or destructively with the ENSO impact and thus enhance or reduce the ENSO-induced predictable signal. This may result in decade-long changes in the connection between ENSO and the Indian monsoon. The physical mechanism for the connection between ENSO and the Indian monsoon may be understood as large-scale adjustment of atmospheric heatings and circulations to the ENSO-induced SST variations. These adjustments modify the Walker circulation and connect the rising/sinking motion in the central-eastern Pacific during a warm/cold ENSO event with sinking/rising motion in the Indian region, leading to reduced/increased rainfall.

Article

Even though many features of the vegetation and of the soil moisture distribution over Africa reflect its climatic zones, the land surface has the potential to feed back on the atmosphere and on the climate of Africa. The land surface and the atmosphere communicate via the surface energy budget. A particularly important control of the land surface, besides its control on albedo, is on the partitioning between sensible and latent heat flux. In a soil moisture-limited regime, for instance, an increase in soil moisture leads to an increase in latent heat flux at the expanse of the sensible heat flux. The result is a cooling and a moistening of the planetary boundary layer. On the one hand, this thermodynamically affects the atmosphere by altering the stability and the moisture content of the vertical column. Depending on the initial atmospheric profile, convection may be enhanced or suppressed. On the other hand, a confined perturbation of the surface state also has a dynamical imprint on the atmospheric flow by generating horizontal gradients in temperature and pressure. Such gradients spin up shallow circulations that affect the development of convection. Whereas the importance of such circulations for the triggering of convection over the Sahel region is well accepted and well understood, the effect of such circulations on precipitation amounts as well as on mature convective systems remains unclear. Likewise, the magnitude of the impact of large-scale perturbations of the land surface state on the large-scale circulation of the atmosphere, such as the West African monsoon, has long been debated. One key issue is that such interactions have been mainly investigated in general circulation models where the key involved processes have to rely on uncertain parameterizations, making a definite assessment difficult.

Article

Swadhin Behera and Toshio Yamagata

The El Niño Modoki/La Niña Modoki (ENSO Modoki) is a newly acknowledged face of ocean-atmosphere coupled variability in the tropical Pacific Ocean. The oceanic and atmospheric conditions associated with the El Niño Modoki are different from that of canonical El Niño, which is extensively studied for its dynamics and worldwide impacts. A typical El Niño event is marked by a warm anomaly of sea surface temperature (SST) in the equatorial eastern Pacific. Because of the associated changes in the surface winds and the weakening of coastal upwelling, the coasts of South America suffer from widespread fish mortality during the event. Quite opposite of this characteristic change in the ocean condition, cold SST anomalies prevail in the eastern equatorial Pacific during the El Niño Modoki events, but with the warm anomalies intensified in the central Pacific. The boreal winter condition of 2004 is a typical example of such an event, when a tripole pattern is noticed in the SST anomalies; warm central Pacific flanked by cold eastern and western regions. The SST anomalies are coupled to a double cell in anomalous Walker circulation with rising motion in the central parts and sinking motion on both sides of the basin. This is again a different feature compared to the well-known single-cell anomalous Walker circulation during El Niños. La Niña Modoki is the opposite phase of the El Niño Modoki, when a cold central Pacific is flanked by warm anomalies on both sides. The Modoki events are seen to peak in both boreal summer and winter and hence are not seasonally phase-locked to a single seasonal cycle like El Niño/La Niña events. Because of this distinction in the seasonality, the teleconnection arising from these events will vary between the seasons as teleconnection path will vary depending on the prevailing seasonal mean conditions in the atmosphere. Moreover, the Modoki El Niño/La Niña impacts over regions such as the western coast of the United States, the Far East including Japan, Australia, and southern Africa, etc., are opposite to those of the canonical El Niño/La Niña. For example, the western coasts of the United States suffer from severe droughts during El Niño Modoki, whereas those regions are quite wet during El Niño. The influences of Modoki events are also seen in tropical cyclogenesis, stratosphere warming of the Southern Hemisphere, ocean primary productivity, river discharges, sea level variations, etc. A remarkable feature associated with Modoki events is the decadal flattening of the equatorial thermocline and weakening of zonal thermal gradient. The associated ocean-atmosphere conditions have caused frequent and persistent developments of Modoki events in recent decades.

Article

The Atlantic meridional overturning circulation (AMOC) is a large, basin-scale circulation located in the Atlantic Ocean that transports climatically important quantities of heat northward. It can be described schematically as a northward flow in the warm upper ocean and a southward return flow at depth in much colder water. The heat capacity of a layer of 2 m of seawater is equivalent to that of the entire atmosphere; therefore, ocean heat content dominates Earth’s energy storage. For this reason and because of the AMOC’s typically slow decadal variations, the AMOC regulates North Atlantic climate and contributes to the relatively mild climate of Europe. Hence, predicting AMOC variations is crucial for predicting climate variations in regions bordering the North Atlantic. Similar to weather predictions, climate predictions are based on numerical simulations of the climate system. However, providing accurate predictions on such long timescales is far from straightforward. Even in a perfect model approach, where biases between numerical models and reality are ignored, the chaotic nature of AMOC variability (i.e., high sensitivity to initial conditions) is a significant source of uncertainty, limiting its accurate prediction. Predictability studies focus on factors determining our ability to predict the AMOC rather than actual predictions. To this end, processes affecting AMOC predictability can be separated into two categories: processes acting as a source of predictability (periodic harmonic oscillations, for instance) and processes acting as a source of uncertainty (small errors that grow and significantly modify the outcome of numerical simulations). To understand the former category, harmonic modes of variability or precursors of AMOC variations are identified. On the other hand, in a perfect model approach, the sources of uncertainty are characterized by the spread of numerical simulations differentiated by the application of small differences to their initial conditions. Two alternative and complementary frameworks have arisen to investigate this spread. The pragmatic framework corresponds to performing an ensemble of simulations, by imposing a randomly chosen small error on the initial conditions of individual simulations. This allows a probabilistic approach and to statistically characterize the importance of the initial condition by evaluating the spread of the ensemble. The theoretical framework uses stability analysis to identify small perturbations to the initial conditions, which are conducive to significant disruption of the AMOC. Beyond these difficulties in assessing the predictability, decadal prediction systems have been developed and tested through a range of hindcasts. The inherent difficulties of operational forecasts span from developing efficient initialization methods to setting accurate radiative forcing to correcting for model drift and bias, all these improvements being estimated and validated through a range of specifically designed skill metrics.

Article

Venus is a slowly rotating planet with a thick atmosphere (~9.2 MPa at the surface). Ground- and satellite-based observations have shown atmospheric superrotation (atmospheric rotation much faster than solid surface rotation), global-scale cloud patterns (e.g., Y-shaped and bow-shaped structures), and polar vortices (polar hot dipole and fine structures). The Venusian atmospheric circulation, controlled by the planet’s radiative forcing and astronomical parameters, is quite different from the earth’s. As the meteorological data have been stored, understanding of the atmospheric circulation has been gradually enriched with the help of theories of geophysical fluid dynamics and meteorology. In the cloud layer far from the surface (49–70 km altitude), superrotational flows (east-to-west zonal winds) exceeding 100 m/s and meridional (equator-to-pole) flows have been observed along with planetary-scale brightness variations unique to Venus. The fully developed superrotation, which is ~60 times faster than the planetary rotation, is maintained by meridional circulation and waves. For the planetary-scale variations, slow-traveling waves with stationary and solar-locked structures and fast-traveling waves with phase velocities of around the superroational wind speeds are dominant in the cloud layer. Thermal tides, Rossby waves, Kelvin waves, and gravity waves play important roles in mechanisms for maintaining fast atmospheric rotation. In the lower atmosphere below the cloud layer, the atmospheric circulation is still unknown because of the lack of global observations. In addition to the limited observations, the atmospheric modeling contributes to deep understanding of the atmospheric circulation system. Recent general circulation models have well simulated the dynamical and thermal structures of Venus’s atmosphere, though there remain outstanding issues.

Article

The Tibetan Plateau (TP) is subjected to strong interactions among the atmosphere, hydrosphere, cryosphere, and biosphere. The Plateau exerts huge thermal forcing on the mid-troposphere over the mid-latitude of the Northern Hemisphere during spring and summer. This region also contains the headwaters of major rivers in Asia and provides a large portion of the water resources used for economic activities in adjacent regions. Since the beginning of the 1980s, the TP has undergone evident climate changes, with overall surface air warming and moistening, solar dimming, and decrease in wind speed. Surface warming, which depends on elevation and its horizontal pattern (warming in most of the TP but cooling in the westernmost TP), was consistent with glacial changes. Accompanying the warming was air moistening, with a sudden increase in precipitable water in 1998. Both triggered more deep clouds, which resulted in solar dimming. Surface wind speed declined from the 1970s and started to recover in 2002, as a result of atmospheric circulation adjustment caused by the differential surface warming between Asian high latitudes and low latitudes. The climate changes over the TP have changed energy and water cycles and has thus reshaped the local environment. Thermal forcing over the TP has weakened. The warming and decrease in wind speed lowered the Bowen ratio and has led to less surface sensible heating. Atmospheric radiative cooling has been enhanced, mainly through outgoing longwave emission from the warming planetary system and slightly enhanced solar radiation reflection. The trend in both energy terms has contributed to the weakening of thermal forcing over the Plateau. The water cycle has been significantly altered by the climate changes. The monsoon-impacted region (i.e., the southern and eastern regions of the TP) has received less precipitation, more evaporation, less soil moisture and less runoff, which has resulted in the general shrinkage of lakes and pools in this region, although glacier melt has increased. The region dominated by westerlies (i.e., central, northern and western regions of the TP) received more precipitation, more evaporation, more soil moisture and more runoff, which together with more glacier melt resulted in the general expansion of lakes in this region. The overall wetting in the TP is due to both the warmer and moister conditions at the surface, which increased convective available potential energy and may eventually depend on decadal variability of atmospheric circulations such as Atlantic Multi-decadal Oscillation and an intensified Siberian High. The drying process in the southern region is perhaps related to the expansion of Hadley circulation. All these processes have not been well understood.

Article

Robert Alan Brookey and Jason Phillips

Michael Warner is the Seymour H. Knox Professor of English and American Studies at Yale University, and his career has followed an interesting trajectory, beginning with the study of print and its importance to the emerging American nation and extending into queer theory and contemporary politics. There is an important line of thought that connects three of Michael Warner’s books: The Letters of the Republic (1990), Publics and Counterpublics (2002), and The Trouble with Normal (1999). In The Letters of the Republic, Warner begins to outline the way in which publics emerge and are discursively produced. In Publics and Counterpublics, he more thoroughly engages both the production of normative publics and the resistant communities of counterpublics, the latter of which he often illustrates with examples drawn from queer communities. Finally, in The Trouble with Normal, Warner challenges the efforts of gay and lesbian rights advocates to accommodate and assimilate to heteronormative standards in an effort to join the public constituted by the dominant heterosexual society. As he notes, these efforts effectively undermine the transformative qualities that queerness can bring to a society in refiguring the way sex and relationships are regarded. In effect, The Trouble with Normal seems to be a queer, counterpublic polemic, one that mirrors (in purpose, if not in content) the emerging revolutionary discourse in 18th-century America. In addition, Warner provides some valuable perspectives on the development of public discourse in American, and makes several observations that pre-date, yet bring into sharp relief, some of the issues and concerns that have been raised about social media.

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Print culture refers to the production, distribution, and reception of printed material. It includes the concepts of authorship, readership, and impact and entails the intersection of technological, political, religious, legal, social, educational, and economic practices, all of which can vary from one cultural context to another. Prior to their arrival in the Americas, Spain and Portugal had their own print culture and, following the conquest, they introduced it into their colonies, first through the importation of books from Europe and later following the establishment of the printing press in Mexico in 1539. Throughout the colonial period, the importation of books from abroad was a constant and lucrative practice. However, print culture was not uniform. As in Europe, print culture in Latin America was largely an urban phenomenon, with restricted readership due to high rates of illiteracy, which stemmed from factors of class, gender, race, and income, among others. Furthermore, the press itself spread slowly and unevenly, according to the circumstances of each region. One thing, however, that these territories had in common was widespread censorship. Reading, writing, and printing were subject to oversight by the Inquisition, whose responsibility was to police the reading habits of the populace and to ensure that no texts were printed that could disrupt the political and religious well-being of the colonies, as they defined it. In spite of Inquisitorial restrictions, print culture flourished and the number and kind of materials available increased dramatically until the early 19th century, when most of the territories under the Iberian monarchies became independent, a phenomenon due in part to the circulation of Enlightenment thought in the region. Following the era of revolutions, newly established republics attempted to implement freedom of the press. While the Inquisition no longer existed, censorship continued to be practiced to a greater or lesser degree, depending on the circumstances and who was in power. This also applies to Cuba and Puerto Rico. Immediately prior to Latin American independence, the United States became a sovereign nation. Commercial and cultural exchanges, including print materials, between the United States and Latin America increased, and many Latin Americans were traveling to and residing in the United States for extended periods. However, it was also in this period that the United States began a campaign of expansionism that did not cease until 1898 and resulted in the acquisition of half of Mexico’s national territory and of Spain’s remaining American colonies, Cuba and Puerto Rico. In addition to the land itself, the United States also “acquired” the people who had been Spanish and Mexican citizens in California, the Southwest, and Puerto Rico. With this change in sovereignty came a change in language, customs, and demographics, which provoked a cultural crisis among these new Latina/o citizens. To defend themselves against the racial persecution from Anglo-Americans and to reverse the impending annihilation of their culture and language, they turned to the press. The press allowed Latinas/os a degree of cultural autonomy, even as their position was slowly eroded by legal and demographic challenges as the 19th century progressed.