scholarly journals Mixing in the Transition Layer during Two Storm Events

2011 ◽  
Vol 41 (1) ◽  
pp. 42-66 ◽  
Author(s):  
Kathleen Dohan ◽  
Russ E. Davis
Keyword(s):  
Mixed Layer ◽  
Transition Layer ◽  
Wavelet Transforms ◽  
Ocean Dynamics ◽  
Small Scale ◽  
Storm Events ◽  
Inertial Waves ◽  
Space Time Structure ◽  
Inertial Energy

Abstract Upper-ocean dynamics analyzed from mooring-array observations are contrasted between two storms of comparable magnitude. Particular emphasis is put on the role of the transition layer, the strongly stratified layer between the well-mixed upper layer, and the deeper more weakly stratified region. The midlatitude autumn storms occurred within 20 days of each other and were measured at five moorings. In the first storm, the mixed layer follows a classical slab-layer response, with a steady deepening during the course of the storm and little mixing of the thermocline beneath. In the second storm, rather than deepening, the mixed layer shoals while intense near-inertial waves are resonantly excited within the mixed layer. These create a large shear throughout the transition layer, generating turbulence that broadens the transition layer. Details of the space–time structure of the frequencies in both short waves and near-inertial waves are presented. Small-scale waves are excited within the transition layer. Their frequencies change with time and there are no clear peaks at harmonics of inertial or tidal frequencies. Wavelet transforms of the inertial oscillations show the evolution as a spreading in frequency, a deepening of the core into the transition layer, and a shift off the inertial frequency. A second near-inertial energy core appears below the transition layer at all moorings coincident with a rapid decay of mixed layer currents. An overall result is that direct wind-generated motions extend to the depth of the transition layer. The transition layer is a location of enhanced wave activity and enhanced shear-driven mixing.

Role of ocean dynamics in the evolution of mixed-layer temperature in the Bay of Bengal during the summer monsoon

2021 ◽  
pp. 101895
Author(s):  
Vineet Jain ◽  
D. Shankar ◽  
P.N. Vinayachandran ◽  
A. Mukherjee ◽  
P. Amol
Keyword(s):  
Summer Monsoon ◽  
Mixed Layer ◽  
Bay Of Bengal ◽  
Ocean Dynamics ◽  
Mixed Layer Temperature

scholarly journals On the Emergence of the Atlantic Multidecadal SST Signal: A Key Role of the Mixed Layer Depth Variability Driven by North Atlantic Oscillation

2020 ◽  
Vol 33 (9) ◽  
pp. 3511-3531
Author(s):  
Ayako Yamamoto ◽  
Hiroaki Tatebe ◽  
Masami Nonaka
Keyword(s):  
Heat Flux ◽  
North Atlantic Oscillation ◽  
Mixed Layer ◽  
North Atlantic ◽  
Mixed Layer Depth ◽  
Vertical Component ◽  
Surface Heat ◽  
Ocean Dynamics ◽  
Layer Depth

AbstractDespite its wide-ranging potential impacts, the exact cause of the Atlantic multidecadal oscillation/variability (AMO/AMV) is far from settled. While the emergence of the AMO sea surface temperature (SST) pattern has been conventionally attributed to the ocean heat transport, a recent study showed that the atmospheric stochastic forcing is sufficient. In this study, we resolve this conundrum by partitioning the multidecadal SST tendency into a part caused by surface heat fluxes and another by ocean dynamics, using a preindustrial control simulation of a state-of-the-art coupled climate model. In the model, horizontal ocean heat advection primarily acts to warm the subpolar SST as in previous studies; however, when the vertical component is also considered, the ocean dynamics overall acts to cool the region. Alternatively, the heat flux term is primarily responsible for the subpolar North Atlantic SST warming, although the associated surface heat flux anomalies are upward as observed. Further decomposition of the heat flux term reveals that it is the mixed layer depth (MLD) deepening that makes the ocean less susceptible for cooling, thus leading to relative warming by increasing the ocean heat capacity. This role of the MLD variability in the AMO signature had not been addressed in previous studies. The MLD variability is primarily induced by the anomalous salinity transport by the Gulf Stream modulated by the multidecadal North Atlantic Oscillation, with turbulent fluxes playing a secondary role. Thus, depending on how we interpret the MLD variability, our results support the two previously suggested frameworks, yet slightly modifying the previous notions.

Quantifying the Role of Ocean Dynamics in Ocean Mixed-Layer Temperature Variability

2021 ◽  
pp. 1-63
Author(s):  
Casey R. Patrizio ◽  
David W.J. Thompson
Keyword(s):  
Mixed Layer ◽  
Temperature Variability ◽  
Ocean Dynamics ◽  
Western Boundary ◽  
Ocean Mixed Layer ◽  
Low Frequencies ◽  
Mixed Layer Temperature ◽  
Equatorial Upwelling ◽  
Key Aspects

AbstractUnderstanding the role of the ocean in climate variability requires first understanding the role of ocean dynamics in ocean mixed layer and thus sea surface temperature variability. However, key aspects of the spatially and temporally varying contributions of ocean dynamics to such variability remain unclear. Here, the authors quantify the contributions of ocean-dynamical processes to mixed layer temperature variability on monthly to multiannual timescales across the globe. To do so, they use two complementary but distinct methods: 1) a method in which ocean heat transport is estimated directly from a state-of-the-art ocean state estimate spanning 1992-2015; and 2) a method in which it is estimated indirectly from observations between 1980-2017 and the energy budget of the mixed layer. The results extend previous studies by providing quantitative estimates of the role of ocean dynamics in mixed layer temperature variability throughout the globe, across a range of timescales, in a range of available measurements, and using two different methods. Consistent with previous studies, both methods indicate that the ocean-dynamical contribution to mixed layer temperature variance is largest over western boundary currents, their eastward extensions, and regions of equatorial upwelling. In contrast to previous studies, the results suggest that ocean dynamics reduce the variance of Northern Hemisphere mixed layer temperatures on timescales longer than a few years. Hence, in the global-mean, the fractional contribution of ocean dynamics to mixed layer temperature variability decreases at increasingly low-frequencies. Differences in the magnitude of the ocean-dynamical contribution based on the two methods highlight the critical need for improved and continuous observations of the ocean mixed layer.

The role of collective identifications in family processes of post-trauma reconstruction: An exploratory study with Kurdish refugee families and their diasporic community

2017 ◽  
Vol 5 (2) ◽  
pp. 107-133 ◽  
Author(s):  
Ruth Kevers ◽  
Peter Rober ◽  
Lucia De Haene
Keyword(s):  
Thematic Analysis ◽  
Exploratory Study ◽  
Meaning Making ◽  
Family Processes ◽  
Small Scale ◽  
Refugee Families ◽  
Family Contexts ◽  
Diasporic Community ◽  
And Coping

While collective identifications of diasporic Kurds have attracted considerable scholarly interest, their possible role in familial processes of post-trauma reconstruction has hardly been studied. The aim of this article is therefore to develop an explorative understanding of the deployment and meaning of collective identifications in intimate family contexts by examining the interconnectedness between the transmission of cultural and political belonging and post-trauma meaning-making and coping in Kurdish refugee families. After contextualising diasporic Kurds’ collective identifications through an ethnographic depiction of the Kurdish diasporic community in Belgium, this article reports on findings from a small-scale, exploratory study with five Kurdish refugee families in Belgium. Thematic analysis of family and parent interviews indicates how cultural and political identifications may operate as sources of (1) dealing with cultural bereavement and loss; (2) commemorating trauma; and (3) reversing versus reiterating trauma. Overall, this study’s findings support an explorative understanding of collective identifications as meaningful resources in families’ post-trauma reconstruction.ABSTRACT IN KURMANJIRola nasnameyên komelî di pêvajoyên malbatî yên vesazkirina paş-trawmayê de: Xebateke raveker li ser malbatên kurd ên penaber û civakên wan ên dîasporayêTevî ku nasnameyên komelî yên kurdên dîasporayê ta radeyeke baș bûye mijara lêkolînan, rola wan a muhtemel di pêvajoyên malbatî yên vesazkirina (selihandin) paş-trawmayê qet nehatine vekolîn. Lewma armanca vê gotarê ew e têgihiştineke raveker pêş bixe li ser rol û wateya nasnameyên komelî yên di çarçoveya mehremiya malbatê de, ku vê yekê jî dê bi rêya vekolîna wê têkiliya rijd bike ya di navbera neqlkirina aidiyetên çandî-siyasî û rêyên sazkirina wateyê û serederîkirina li dû trawmayê di nav malbatên kurd ên penaber de. Piştî diyarkirina çarçoveya nasnameya komelî ya Kurdên diasporayê bi rêya teswîreke etnografîk a cemaeta diasporaya Kurd li Belçîkayê, ev gotar encamên ji xebateke biçûk a bi pênc malbatên kurd ên penaber ên li Belçîkayê pêşkêş dike. Tehlîla babetî ya hevpeyvînên ligel malbatan û dayik û bavan nîşan dide ka çawa nasnameyên çandî û siyasî dikarin bibin çavkanî ji bo (1) serederîkirina bi mehrûmiyeta çandî û windahiyên xwe; (2) bibîranîna trawmayê; û (3) kêmrengkirin an, beramber vê yekê, dubarekirina trawmayê. Bi giştî, encamên vê xebatê wê têgihiştineke raveker tesdîq dikin ku nasnameyên kolektîf çavkaniyên kêrhatî ne di vesazkirina paş-trawmayê ya malbatan de. ABSTRACT IN SORANIDewrî nasname bekomellekan le prose binemalleyîyekanî sazkirdinewey paş-trawmayîda: lêkollîneweyekî şirovekarî binemalle penabere kurdekan û civatî ewan le diyasporaLe katêkda nasname bekomellekanî kurdekanî diyaspora le layen şarezakanewe giringîyekî berçawî pê drawe û serincî ewanî bo lay xoyî rakêşawe, bellam sebaret be egerî dewrî prose binemalleyîyekanî sazkirdinewey paş-tirawma be degmen lêkollîneweyek encam drawe. Ke wate, amancî em wutare perepêdan be têgeyîştinêkî şirovekarane lemerr bekarhênan û manay nasname bekomellekan le bestênekanî têkellawîy binemalleyîdaye, ke le rêgey peywendîy nêwan rewtî gwastineweyî grêdraweyî kultûrî û siyasî, sazbûnî mana û herweha rahatin legell kêşekanî qonaẍî paş tirawma le binemalle kurde penaberekanda taqî krawetewe. Dway awirrdanewe le civakî diyasporay kurd le Belcîka, nasname bekomellekanî kurdekanî diyaspora le bestênî xoyda xwêndinewey bo krawe û bem gêreye lem wutareda lêkollîneweyekî şirovekarane bo qebareyekî biçûk le pênc binemalley kurdî penaber le Belcîka dekrê û encamekanî billaw dekrêtewe. Şîkarîyekî babetiyaney wutuwêj legell binemalle û dayk û bawkekan nîşanî dedat ke çon dekrê nasname kultûrî û siyasîyekan wek serçaweyek bo em sê mijare derbikewn: (1) gîrodebûn be ledestçûn û bizirbûnî kultûr; (2) webîrhênanewey tirawma; û (3) pêçewanebûnî tirawma leberamber dûbarebûneweyda. Beşêweyekî giştî, encamekanî em lêkollîneweye piştgîrî le têgeyîştinêkî şirovekarane le nasname bekomellekan dekat ke wekû serçaweyekî giring bo sazkirdinewey binemallekan le dway qonaẍî paş-tirawma seyr dekrêt.

GOELRO plan is 100 years old

2020 ◽  
Vol 12 (12) ◽  
pp. 4-9
Author(s):  
Pavel A. BUTYRIN ◽  
Keyword(s):  
Agricultural Production ◽  
Historical Context ◽  
Soviet Period ◽  
Small Scale ◽  
Efficient Production ◽  
Soviet Republic ◽  
Starting Conditions ◽  
Per Capita ◽  
State Plan

The historical context in which the State Plan for Electrification of Russia (GOELRO) was developed, establishment of the GOELRO Commission, the GOELRO Plan content, the specific features of its implementation, and the role of the plan in the soviet period of Russia’s history are considered. Attention is paid to the electrification plants of other countries and territories of all inhabited continents, and to the participation of states in the electrification of countries and regions with small-scale and agricultural production in the 1920 s. The specific features pertinent to the electrification of the Russian Socialist Federative Soviet Republic are pointed out, namely, low starting conditions (in 1923, the energy consumption per capita in Russia was 100 times lower than that in Norway), its being state-owned in nature and revolutionary in its purpose: to get done with the main upheavals in the country and to shift the national economy for fore efficient production. The role of V.I. Lenin and G.M. Krzhizhanovsky, who were the initiators of the electrification of Russia, is analyzed in detail. A conclusion is drawn about the need to study both the GOELRO Plan itself and the specific features and circumstances of its implementation within the framework of training modern specialists in electrical engineering.

Mixed Layer Models and Their Application to Water Quality Problems

1994 ◽  
Vol 29 (2-3) ◽  
pp. 221-232
Author(s):  
M.J. McCormick
Keyword(s):  
Water Quality ◽  
Mixed Layer ◽  
Thermal Structure ◽  
Mass Conservation ◽  
Eddy Diffusion ◽  
Rate Of Change ◽  
Surface Mixed Layer ◽  
Storm Events ◽  
Quality Model ◽  
Mixing Processes

Abstract Four one-dimensional models which have been used to characterize surface mixed layer (ML) processes and the thermal structure are described. Although most any model can be calibrated to mimic surface water temperatures, it does not imply that the corresponding mixing processes are well described. Eddy diffusion or "K" models can exhibit this problem. If a ML model is to be useful for water quality applications, then it must be able to resolve storm events and, therefore, be able to simulate the ML depth, h, and its time rate of change, dh/dt. A general water quality model is derived from mass conservation principles to demonstrate how ML models can be used in a physically meaningful way to address water quality issues.

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