Intraseasonal response of mixed layer temperature and salinity in the Bay of Bengal to heat and freshwater flux

Buoy and satellite data show pronounced subseasonal oscillations of sea surface temperature (SST) in the summertime Bay of Bengal. The SST oscillations are forced mainly by surface heat flux associated with the active break cycle of the south Asian summer monsoon. The input of freshwater (FW) from summer rain and rivers to the bay is large, but not much is known about subseasonal salinity variability. We use 2002-2007 observations from three Argo floats with 5 day repeat cycle to study the subseasonal response of temperature and salinity to surface heat and freshwater flux in the central Bay of Bengal. About 95% of Argo profiles show a shallow halocline, with substantial variability of mixed layer salinity. Estimates of surface heat and freshwater flux are based on daily satellite data sampled along the float trajectory. We find that intraseasonal variability of mixed layer temperature is mainly a response to net surface heat flux minus penetrative radiation during the summer monsoon season. In winter and spring, however, temperature variability appears to be mainly due to lateral advection rather than local heat flux. Variability of mixed layer freshwater content is generally independent of local surface flux (precipitation minus evaporation) in all seasons. There are occasions when intense monsoon rainfall leads to local freshening, but these are rare. Large fluctuations in FW appear to be due to advection, suggesting that freshwater from rivers and rain moves in eddies or filaments.

Personnel Managers and Crisis Situations. Emotion-handling Strategies

This study focuses on personnel managers in crisis situations. The interviewed personnel managers referred to emotions as a central element to be dealt with in a crisis. However, until recently, the exploration of emotions in organisational life has been de-emphasised or ignored. This study aims to bring to the surface aspects of personnel work that have so far been neglected or remained invisible. It specifically examines how personnel managers handle employees’ and their own emotions in a crisis. Based on the interviews, a number of emotional episodes were constructed. They describe the type and context of the crisis and the person(s) whose emotions are handled. The main findings of the study are the five emotion-handling strategies that could be constructed from the data. The negotiation-like manner in which personnel managers handled emotions in crisis situations proved especially interesting. They were actually negotiating emotional value for their organisations. Further, they handled their own emotions within the frame of two logics of appropriateness labelled mothering and guide-following. The episodes described also enabled identification of the values enacted by the personnel managers in handling emotions. The study provides descriptive information on emotion handling, a current and relevant feature in the practice of personnel management. It seeks to offer a frame for developing practical principles that can be helpful in a crisis. It also offers the opportunity to consider a variety of difficult situations that personnel managers may confront in their work.

Narrative, Memory and the Crisis of Mimesis: the Case of Adam Elsheimer and Giordano Bruno

The triangular space between memory, narrative and pictorial representation is the terrain on which this article is developed. Taking the art of memory developed by Giordano Bruno (1548 – 1600) and the art of painting subtly revolutionised by Adam Elsheimer (1578 – 1610) as test-cases, it is shown how both subvert the norms of mimesis and narration prevalent throughout the Renaissance, how disrupted memory creates “incoherent” narratives, and how perspective and the notion of “place” are questioned in a corollary way. Two paintings by Elsheimer are analysed and shown to include, in spite of their supposed “realism”, numerous incoherencies, aporias and strange elements – often overlooked. Thus, they do not conform to two of the basic rules governing both the classical art of memory and the humanist art of painting: well-defined places and the exhaustive translatability of words into images (and vice-versa). In the work of Bruno, both his philosophical claims and the literary devices he uses are analysed as hints for a similar (and contemporaneous) undermining of conventions about the transparency and immediacy of representation.

Circulation and salinity distribution in coastal inlets

The mathematical model developed by Hansen and Rattray based on Pritchard's equations for a coastal-plain estuary has been analysed to study the circulation and salinity distributions in coastal inlets with constant width and depth. Numerical solutions of the basic equations have been obtained without placing any restriction on Rayleigh numbers. A noteworthy contribution of the present analysis is that solutions of equations have been obtained for higher Rayleigh numbers, which was not possible in the earlier model. It is found that the effect of higher Rayleigh numbers is to increase the vertical advection, making the salinities in the upper and lower layers more uniform with a distinct halocline near the mid-depths. Solutions are discussed for some special cases of practical interest.

Short- and long-term temporal variations in salinity and the oxygen, carbon and hydrogen isotopic compositions of the Hooghly Estuary water, India

The Hooghly River estuary provides a unique experimental site to understand the effect of monsoonal river discharge on freshwater and seawater mixing. Water samples collected bi-weekly for a duration of 17 months were analyzed for salinity, delta O-18,delta C-13(DIC), as well as delta D to investigate the differential mixing of freshwater and seawater. The differences in salinity and delta O-18 of samples collected during low and high tides on the same day are strongly correlated suggesting a well mixed water column at our sampling site. Low salinity and depleted delta O-18 during monsoon is consistent with increased river discharge as well as high rainfall. We identified different slopes in a delta O-18 versus salinity plot for the estuary water samples collected during monsoon and non-monsoon seasons. This is driven by composition of the freshwater source which is dominated by rainwater during monsoon and rivers during non-monsoon months. Selected delta D analyses of samples indicate that groundwater contributes significantly to the Hooghly Estuary during low rainfall times of the year. delta C-13(DIC) measured in the water recorded low values towards the end of monsoon indicating low productivity (i.e. increased organic respiration) while progressively increasing delta C-13(DIC) values from October till January as well as during some of the pre-monsoon months can be explained by increasing productivity. Very low delta C-13(DIC) (similar to-20%0) suggests involvement of carbon derived from anaerobic oxidation of organics and/or methane with potential contribution from increased anthropogenic water supply. An estimate of seawater incursion into the Hooghly Estuary at different times of the year is obtained by using salinity data in a two-component mixing model. Presence of seawater was found maximum (31-37%) during February till July and lowest (less than or equal to 6%) from September till November. We notice a temporal offset between Ganges River discharge farther upstream at Farakka and salinity variation at the Hooghly Estuary. We believe that this time lag is a result of the physical distance between Farakka and Kakdweep (our sampling location) and put constraints on the travel time of river water during early monsoon. (c) 2012 Published by Elsevier B.V.

The upper Bay of Bengal salinity structure in a high-resolution model

Salinity in the Bay of Bengal is highly heterogeneous, with extremely fresh waters found at the surface in the Northern part of the basin, and saltier waters at subsurface as well as to the south. This paper investigates the seasonal structure of sea surface salinity of the Bay in a regional high-resolution model forced by ERA-Interim reanalysis and various precipitation products. Surface circulation is believed to drive the spreading of northern Bay of Bengal fresh waters to the rest of the Indian Ocean. We first present a series of experiments to infer the sensitivity of modeled circulation to various numerical choices. Surface circulation is found to be sensitive to the horizontal resolution of the model, with the 1/12 degrees version appearing much more realistic than the 1/4 degrees version. The sidewall boundary condition is also drastically influencing the characteristics of the western boundary current simulated. We then investigate the sensitivity of the salinity response to the various precipitation products. We observe that ERA-Interim excess precipitation induces a fresh bias in the surface salinity response. Spaceborne precipitation products are more satisfactory. We then identify the pathways of the northern Bay freshwater mass, based on passive tracers experiments. Our model suggests that over timescales of a few months, vertical exchanges between the upper fresh layer and the underlying saltier layer appear to be the main export pathway for the freshwater. The horizontal circulation within the mixed layer also acts to convey fresh waters out of the Bay at these timescales, but in a lesser quantity compared to the vertical export. Beyond its intrinsic interest for the understanding of Bay of Bengal physics, this study highlights the need for a careful design of any realistic numerical model, in three key aspects: the choice of the resolution of the model, the choice of the sub-grid scale parameterizations, and the choice of the forcing fluxes. (C) 2013 Elsevier Ltd. All rights reserved.

A modeling study of the processes of surface salinity seasonal cycle in the Bay of Bengal

In response to the Indian Monsoon freshwater forcing, the Bay of Bengal exhibits a very strong seasonal cycle in sea surface salinity (SSS), especially near the mouths of the Ganges-Brahmaputra and along the east coast of India. In this paper, we use an eddy-permitting (similar to 25 km resolution) regional ocean general circulation model simulation to quantify the processes responsible for this SSS seasonal cycle. Despite the absence of relaxation toward observations, the model reproduces the main features of the observed SSS seasonal cycle, with freshest water in the northeastern Bay, particularly during and after the monsoon. The model also displays an intense and shallow freshening signal in a narrow (similar to 100 km wide) strip that hugs the east coast of India, from September to January, in good agreement with high-resolution measurements along two ships of opportunity lines. The mixed layer salt budget confirms that the strong freshening in the northern Bay during the monsoon results from the Ganges-Brahmaputra river discharge and from precipitation over the ocean. From September onward, the East India Coastal Current transports this freshwater southward along the east coast of India, reaching the southern tip of India in November. The surface freshening results in an enhanced vertical salinity gradient that increases salinity of the surface layer by vertical processes. Our results reveal that the erosion of the freshwater tongue along the east coast of India is not driven by northward horizontal advection, but by vertical processes that eventually overcome the freshening by southward advection and restore SSS to its premonsoon values. The salinity-stratified barrier layer hence only acts as a ``barrier'' for vertical heat fluxes, but is associated with intense vertical salt fluxes in the Bay of Bengal.

Los monasterios y la monarquía en época de crisis : Sancho IV

Resumen: El apoyo constante de la realeza a los monasterios en la Edad Media no se vio interrumpido en época de crisis, como la vivida en las postrimerías del reinado de Alfonso X y los comienzos del de Sancho IV, en la que algunos monasterios tradicionales participaron en la Hermandad. Del conflicto realengo- abadengo se sustrae así la realeza hispánica siempre atenta a favorecer a las comunidades monásticas, bastión y símbolos de la espiritualidad medieval así como ordenadoras del espacio y de la vida económica de la región en que se asentaban.

Imaginario y realidad de la muerte de Santa María Egipciaca en el contexto castellano de la crisis del siglo XIV

Resumen: El presente trabajo se propone analizar el sentido y la funcionalidad del tema de la muerte del santo en el contexto de la crisis que afecta a Europa en el siglo XIV, a través de la muerte de Santa María Egipciaca –una de las santas medievales más populares– narrada en la Vida de Santa María Egipciaca, un poema castellano compuesto en el temprano siglo XIII pero transmitido a fines del siglo XIV en el manuscrito K-III-4 de la Biblioteca de San Lorenzo de El Escorial.