Modeling of the M2 surface and internal tides and their seasonal variability in the Arctic Ocean: Dynamics, energetics and tidally induced diapycnal diffusion

Modeling results for the M2 surface and internal tides in the Arctic Ocean (AO) are presented. These incorporate the data on tidal dynamics and energetics and tidally induced diapycnal diffusion. A modified version of the 3D finite-element hydrostatic model QUODDY-4 is used as a basis for modeling. It is shown that the predicted surface tide differs slightly from that obtained from other tidal models, whereas the internal tidal waves (ITW) are less than those in oceans of moderate and low latitudes. It also appears that ITW themselves belong to the family of trapped waves. This finding, together with the modeling results for averaged (over a tidal cycle) horizontal transport per unit length of barotropic tidal energy and depth-integrated density of baroclinic tidal energy, suggests that the ITW generation site is placed to the northwest of the New Siberian Islands. A local rate of baroclinic tidal energy dissipation is found to increase away from the bottom as observed on Mid-Atlantic and Hawaiian ridges, but only within the bottom boundary layer, and two-three orders of magnitude less than in other oceans. Also, the ITW decay scale in both summer and winter lies over the range of its values (100–1000 km) for Mid-Atlantic and Hawaiian ridges. A tidal cycle-, depth- and area-averaged coefficient of diapycnal diffusion is greater than the kinematic viscosity and less (but not much) than the canonical value of the vertical eddy diffusivity in the deep ocean, prescribed in models of global ocean circulation. From this results the conclusion that tidally induced diapycnal diffusion can be meaningful in the formation of the AO climate

Многоликий синдром вегетативной дистонии: клинический случай выявления сочетания аномалии Киммерле и мальформации Киари

Highlights. Autonomic dysfunction syndrome is an urgent issue in modern medicine, however, it should be an exceptional diagnosis, established after a comprehensive diagnostic study, as many diseases can often appear as this syndrome. The presented case describes the patient with a combined pathology of Kimmerle`s anomaly and Chiari malformation, who was diagnosed with autonomic dysfunction long time ago.Abstract. Autonomic dysfunction syndrome (ADS) is a topical issue of modern medicine. Differential diagnosis of this syndrome is often a difficult task for a practicing physician, because an organic disease of various etiologies can be hidden under the guise of autonomic dysfunction. The article analyzes a clinical case of a patient with a combined pathology of Kimmerle`s and Arnold-Chiari anomalies, which were not diagnosed for a long time due to the fact that clinical symptoms (syncope and presyncope conditions, dizziness, pain in the occipital region, aggravated by physical exertion and emotional stress, rises in blood pressure up to 160 mm Hg) are identical to those in ADS. After prolonged treatment of ADS without any positive effect, the child was sent to the Research Clinical Institute of Pediatrics and Pediatric Surgery named after academician Yuri Veltischev. Having received surgical treatment, the patient had no complaints for 6 months. The presented clinical case confirms that the diagnosis of ADS should be an exceptional diagnosis, established only after a complex and comprehensive examination.Основные положения. Синдром вегетативной дисфункции является актуальным вопросом современной медицины, но должен оставаться диагнозом-исключением, устанавливаемым после полноценного диагностического поиска, так как зачастую под маской синдрома скрываются другие заболевания. В данном клиническом случае описано выявление сочетания аномалии Киммерле и мальформации Киари у пациента, основным диагнозом которого долгое время был синдром вегетативной дисфункции.Резюме. Синдром вегетативной дисфункции (СВД) – актуальный вопрос современной медицины. Дифференциальная диагностика данной патологии часто выступает сложной задачей для практикующего врача, ведь под маской вегетативной дисфункции может скрываться органическое заболевание различной этиологии. В статье описан случай выявления у ребенка сочетанных аномалий Киммерле и Арнольда – Киари, которые долгое время не были диагностированы из-за того, что клиническая симптоматика (синкопальные и пресинкопальные состояния, головокружения, боли в затылочной области, усиливающиеся при физических нагрузках и эмоциональном напряжении, подъемы артериального давления до 160 мм рт. ст.) идентична таковой при СВД. После продолжительного неэффективного лечения СВД больная направлена на обследование в Научно-исследовательский клинический институт педиатрии и детской хирургии имени академика Ю.Е. Вельтищева, где после ряда дополнительных исследований установлены вышеуказанные аномалии, вызывавшие клиническую симптоматику, беспокоившую пациентку. После хирургического лечения пациентка в течение 6 мес. жалоб не предъявляла. Представленный клинический случай подтверждает, что СВД должен быть диагнозом-исключением, который ставят после комплексного и всеобъемлющего обследования

Effects of lateral processes on the seasonal water stratification of the Gulf of Finland: 3-D NEMO-based model study

This paper aims to fill the gaps in knowledge of processes affecting the seasonal water stratification in the Gulf of Finland (GOF). We used a state-of-the-art modelling framework NEMO (Nucleus for European Modelling of the Ocean) designed for oceanographic research, operational oceanography, seasonal forecasting, and climate studies to build an eddy-resolving model of the GOF. To evaluate the model skill and performance, two different solutions were obtained on 0.5 km eddy-resolving and commonly used 2 km grids for a 1-year simulation. We also explore the efficacy of non-hydrostatic effect (convection) parameterizations available in NEMO for coastal application. It is found that the solutions resolving submesoscales have a more complex mixed layer structure in the regions of the GOF directly affected by the upwelling/downwelling and intrusions from the open Baltic Sea. Presented model estimations of the upper mixed layer depth are in good agreement with in situ CTD (BED) data. A number of model sensitivity tests to the vertical mixing parameterization confirm the model's robustness. Further progress in the submesoscale process simulation and understanding is apparently not connected mainly with the finer resolution of the grids, but with the use of non-hydrostatic models because of the failure of the hydrostatic approach at submesoscale