scholarly journals Study of temporary variability of vertical structure parameters of water in the coastal zone of southern Crimea

2021 ◽  
Vol 27 (3) ◽  
pp. 49-58
Author(s):  
Sergey Kazakov
Keyword(s):  
Coastal Zone ◽  
Temporal Variability ◽  
Vertical Structure ◽  
Subsurface Layer ◽  
Measurement Data ◽  
Lower Boundary ◽  
Wind Component ◽  
Vertical Temperature ◽  
Vertical Temperature Profile ◽  
Upwelling And Downwelling

The issues of the formation and temporal variability of the vertical structure of the Black Sea waters off the coast of the southern Crimea are considered. A large array of instrumental measurement data obtained in the second half of 2013 (June–December) during operational monitoring of the vertical temperature profile in the area of Stationary oceanographic platform of the Marine Hydrophysical Institute in the coastal zone near Cape Kikineiz is used. The measurements were carried out using a thermoline, which is a system of temperature sensors distributed in depth from the surface to the bottom. To study the vertical structure of the temperature field, a model of two-layer stratification is considered, when two quasi-homogeneous layers (the upper one is warmer and the lower one cold) are separated by a layer of large vertical temperature gradients—the thermocline. A number of parameters of the vertical structure of waters were calculated: the vertical temperature gradient, its maximum values and depth of occurrence, the temperature of the thermocline core (if it was recorded) and quasi-uniform layers, the temperature difference between these layers, and the thermocline thickness. The median estimates of the daily values of the listed parameters are analyzed. Specific cases of transformation of the vertical profile of water temperature during the upwelling and downwelling processes are considered. It is shown that the temporal variability of the parameters of the vertical structure is significant, especially in the summer hydrological season. The main contribution to the variability is caused by the seasonal course of the heat flow from the atmosphere through the sea surface and surge processes (upwelling and downwelling) in the summer period caused by abrupt changes in the alongshore wind component. In the autumn hydrological season, the thermocline is recorded sporadically with a slight gradient in the form of the lower boundary of the subsurface layer of daytime heating, or a thin bottom layer.

scholarly journals EFFECT OF DUST AEROSOL LAYER ON VERTICAL TEMPERATURE PROFILE

MAUSAM ◽  
2022 ◽  
Vol 53 (4) ◽  
pp. 539-542
Author(s):  
A. P. DIMRI ◽  
V. K. JAIN ◽  
B. B. DASH
Keyword(s):  
Temperature Profile ◽  
Dust Aerosol ◽  
Aerosol Layer ◽  
Vertical Temperature ◽  
Vertical Temperature Profile

scholarly journals FROM THE POLYGON-70 EXPERIMENT TO THE ABYSSAL EXPERIMENT

2020 ◽  
Vol 48 (3) ◽  
pp. 54-75
Author(s):  
O.P. Nikitin
Keyword(s):  
Vertical Structure ◽  
Measurement Data

The article discusses the issues of reconstructing the mesoscale fields of hydrophysical characteristics from measurement data, as well as the layout of moorings in the ocean experiments Polygon–70, SDE POLYMODE and Abyssal, in which the author of the article took part. A number of important results of the analysis of the vertical structure and variability of synoptic currents in the regions of these experiments are also presented.

scholarly journals A Hydrodynamical Model for Calculating the Vertical Temperature Profile in Lakes During Cooling

1983 ◽  
Vol 14 (4) ◽  
pp. 239-254 ◽  
Author(s):  
Jörgen Sahlberg
Keyword(s):  
Heat Flux ◽  
Temperature Profile ◽  
Vertical Mixing ◽  
Hydrodynamical Model ◽  
Measured Temperature ◽  
Vertical Temperature ◽  
Mixing Rate ◽  
Mixing Processes ◽  
Vertical Temperature Profile ◽  
Radiation Fluxes

A one-dimensional hydrodynamical model is used for simulating the vertical temperature profile in a lake during cooling conditions. The vertical mixing rate is calculated by solving the equations for turbulent kinetic energy, k, and dissipation of energy, ε. The heat exchange between the water and atmosphere consists of the radiation fluxes, sensible and latent heat flux. Temperature measurements from Lake Väsman during November-December, 1981, were used in the verification study. The agreement between calculated and measured temperature profiles is very good. This indicates that both the mixing processes and the net heat flux are well described in the model.

Effects of lead width variation, re-freezing and mixing events on lead water structure in the central Arctic

2021 ◽  
Author(s):  
Daiki Nomura ◽  
Alison Web ◽  
Yuhong Li ◽  
Manuel Dall’osto ◽  
Katrin Schmidt ◽  
...  
Keyword(s):  
Vertical Structure ◽  
Lower Boundary ◽  
Water Structure ◽  
Sampling Period ◽  
Ice Formation ◽  
Layer Surface ◽  
Mixing Process ◽  
Survey Period ◽  
Mixing Processes ◽  
Surface Ice

<p>We undertook a lead survey during the international drift campaign MOSAiC, Leg 5 (from 22 August to 17 September 2020) to understand the effects of lead width variation, re-freezing, and mixing events on lead water vertical structure. At the beginning of the survey period, the freshwater layer was occupied for the top 1 m depth and there were strong vertical gradients in temperature, salinity, and dissolved oxygen (DO) within 1 m depth: from 0.0°C to –1.6°C for temperature, from 0.0 to 31.4 psu for salinity, and 10.5 to 13.5 mg L<sup>–1</sup> for DO. A strong DO minimum layer corresponded with a salinity of 25 psu, and usually occurred at the freshwater–seawater interface at approx. 1 m depth, most likely as a result of an accumulation of organic matter and ongoing degradation/respiration processes at this interface. However, during the survey period, these strong gradients weakened and reduced the freshwater layer thickness (FLT). In the first half of the sampling period (until 4 September), FLT changed due to variations in lead width: as lead width increased, FLT decreased due to a stretching of the freshwater layer. In the second half of the sampling period, FLT was controlled by the surface ice formation (re-freezing) and mixing processes along the lower boundary of the freshwater layer. Surface ice formation removed freshwater and the formation of surface ice (about 0.2 m thick) explains 20% of the reduction of FLT. The remaining 80% of the reduction of FLT was due to the mixing process within the water column that was initiated by cooling and re-freezing. This mixing process diluted the salinity from 31.6 to 29.3 psu in the water below freshwater layer towards the end of the survey period. Our results indicate that lead water structure can change rapidly and dynamically and that this has significant effects on the biogeochemical exchange between lead systems and the atmosphere.</p>

scholarly journals 2.5D retrieval of atmospheric properties from exoplanet phase curves: application to WASP-43b observations

2020 ◽  
Vol 493 (1) ◽  
pp. 106-125 ◽  
Author(s):  
Patrick G J Irwin ◽  
Vivien Parmentier ◽  
Jake Taylor ◽  
Jo Barstow ◽  
Suzanne Aigrain ◽  
...  
Keyword(s):  
Temperature Profile ◽  
Water Vapour ◽  
Mole Fraction ◽  
Phase Curve ◽  
Vertical Temperature ◽  
Vertical Temperature Profile ◽  
Retrieval Technique ◽  
The Mean ◽  
Synthetic Phase ◽  
Model Phase

ABSTRACT We present a novel retrieval technique that attempts to model phase curve observations of exoplanets more realistically and reliably, which we call the 2.5-dimensional (2.5D) approach. In our 2.5D approach we retrieve the vertical temperature profile and mean gaseous abundance of a planet at all longitudes and latitudes simultaneously, assuming that the temperature or composition, x, at a particular longitude and latitude (Λ, Φ) is given by $x(\Lambda ,\Phi) = \bar{x} + (x(\Lambda ,0) - \bar{x})\cos ^n\Phi$, where $\bar{x}$ is the mean of the morning and evening terminator values of x(Λ, 0), and n is an assumed coefficient. We compare our new 2.5D scheme with the more traditional 1D approach, which assumes the same temperature profile and gaseous abundances at all points on the visible disc of a planet for each individual phase observation, using a set of synthetic phase curves generated from a GCM-based simulation. We find that our 2.5D model fits these data more realistically than the 1D approach, confining the hotter regions of the planet more closely to the dayside. We then apply both models to WASP-43b phase curve observations of HST/WFC3 and Spitzer/IRAC. We find that the dayside of WASP-43b is apparently much hotter than the nightside and show that this could be explained by the presence of a thick cloud on the nightside with a cloud top at pressure <0.2 bar. We further show that while the mole fraction of water vapour is reasonably well constrained to (1–10) × 10−4, the abundance of CO is very difficult to constrain with these data since it is degenerate with temperature and prone to possible systematic radiometric differences between the HST/WFC3 and Spitzer/IRAC observations. Hence, it is difficult to reliably constrain C/O.

Impact of hydrometeorological conditions on the Southern Baltic cliff coast development in the annual and long-term weather cycle

2020 ◽  
Author(s):  
Jacek Tylkowski ◽  
Andrzej Kostrzewski ◽  
Marcin Winowski
Keyword(s):  
Coastal Zone ◽  
Temporal Variability ◽  
Dominant Role ◽  
Spatial Diversity ◽  
Estimation Of Parameters ◽  
Short Term ◽  
Time Decomposition ◽  
Geomorphological Processes ◽  
Southern Baltic ◽  
Hydrometeorological Conditions

<p>To determine the specificity of functioning the Southern Baltic coasts, it is necessary to identify the hydrometeorological conditions that have the greatest effect on the dynamics of geomorphological processes in detail. For the offshore coastal zone, it is important to determine temporal variability (including trend, cyclicality and seasonality) and spatial diversity (i.e. for cliff and dune coasts) of occurrence of main hydrometeorological and geomorphological processes and events. Among hydrometeorological and geomorphological factors - which are decisive for violent, intense and sometimes irreversible changes in the natural environment - extreme events play an important and sometimes dominant role (Tylkowski, Hojan 2018).</p><p>Geomorphological changes of the cliff coast depend mainly on the dynamics of marine and slope erosion. The high sea level that occurs during storm swells and intense precipitation lead to the transformation of the cliff coast, which is seen in the retraction of the cliff crown, among others (Kostrzewski et al. 2015).</p><p>The purpose of the work was to determine the temporal variability of hydrometeorological conditions, which have the greatest effect on the dynamics of the erosion of the cliff shores of the Wolin island. Hydrometeorological conditions from 1985 – 2019 period were compared to the annual measurements of the cliff crown retraction, which were carried out on 5 test sections in the coastal zone of the Pomeranian Bay on the island of Wolin. The work indicates the occurrence of above-average and extreme hydrometeorological events that potentially favoured the occurrence of erosive processes, e.g. mass movements, slopewash and aeolian erosion.</p><p>Using ARIMA modelling, time decomposition of hydrometeorological conditions was made and their short-term forecasts were formulated. The study determined non-seasonal and seasonal parameters that determine the occurrence of current and future meteorological and marine conditions. What is more, spatial differences in the scope of identification of the features of the analysed time series, estimation of parameters of selected models and the formulated forecast are indicated (Tylkowski, Hojan 2019).</p><p> </p><p> </p><p>References</p><p>Tylkowski J., Hojan M., 2018. Threshold values of extreme hydrometeorological events on the Polish Baltic coast. Water 10(10), 1337. doi:10.3390/w10101337</p><p>Kostrzewski A., Zwoliński Z., Winowski M., Tylkowski J., Samołyk M., 2015. Cliff top recesion rate and cliff hazards for the sea coast of Wolin Island (Southern Baltic). Baltica 28(2): 109-120. doi:10.5200/baltica.2015.28.10</p><p>Tylkowski J., Hojan M., 2019: Time decomposition and short-term forecasting of hydrometeorological conditions in the South Baltic coastal zone of Poland. Geosciences 9(68). doi.org/10.3390/geosciences9020068</p>

An Experimental Research on Wall Radiant Cooling and Wall-Attached-Jet Air-Conditioning System

2014 ◽  
Vol 501-504 ◽  
pp. 2244-2251 ◽  
Author(s):  
Xiang Lei Kong ◽  
Xin Li Zi ◽  
Long Yun ◽  
Xiao Song Zhang
Keyword(s):  
Indoor Air ◽  
Air Conditioning ◽  
Stable Operation ◽  
Displacement Ventilation ◽  
Vertical Temperature ◽  
Vertical Temperature Profile ◽  
Air Conditioning System ◽  
Radiant Cooling ◽  
Operation Period ◽  
The Subject

Taking the radiant cooling combined with wall-attached-jet air-conditioning system as the subject in a laboratory of Jiangsu university, an experimental study was carried out on pre-dehumidifying period, stable operation period and system shutdown period, along with analysis. The objective is to analyze the pre-dehumidification of the system, indoor air temperature and humidification change, vertical temperature profile and condensation sensitivity. The results show that the hybrid air-conditioning can provide high thermal comfort and avoid condensation effectively, which shows the better performance compared to the system of radiant cooling combined with displacement ventilation to some extent.

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