scholarly journals Mass-Radius relationships of small, highly irradiated exoplanets with small water mass fractions

2021 ◽  
Author(s):  
Hugo Vivien ◽  
Artem Aguichine ◽  
Olivier Mousis ◽  
Magali Deleuil ◽  
Emmanuel Marcq
Keyword(s):  
Water Mass ◽  
Terrestrial Planets ◽  
Limited Impact ◽  
Small Water ◽  
Final Mass ◽  
Mass Fractions ◽  
Important Amount ◽  
Atmosphere Model ◽  
Do So

<p>This work aims to determine the mass-radius rela-tionships of highly irradiated (500< Tirr<2000K)small planets (0.2<M<2.3M⊕) with water con-tents up to 5%. To do so, we coupled an internalmodel of small terrestrial planets (Brugger et al.,2017) to the atmosphere model elaborated by Marcqet al. (2017, 2019), following the approach depictedin Aguichine et al. (2021) and Mousis et al. (2020).</p> <p>We show that these planets, even with smallwater contents, can become strongly inflated andproduce large radii for small masses.We alsoshow that strongly irradiated small planets cannotsustain their atmospheres due to the lack of hy-drostatic stability, implying they cannot preserveany hydrosphere. The temperature and the watermass fraction are the key parameters controllingthe extent of inflation and the thickness of thesupercritical layer. An important amount of wateralso leads to the contraction of the rocky interior.However, the composition of the rocky interioronly has a limited impact on the final mass-radiusrelationship, and barely impacts the behavior of thehydrosphere.</p>

scholarly journals Pool Boiling Heat Transfer Coefficients in Mixtures of Water and Glycerin

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 830
Author(s):  
Viktor Vajc ◽  
Radek Šulc ◽  
Martin Dostál
Keyword(s):  
Heat Transfer ◽  
Dynamic Method ◽  
Water Mass ◽  
Heat Fluxes ◽  
Static Method ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Mean Relative Error ◽  
Mixture Effects ◽  
Mass Fractions

Heat transfer coefficients were investigated for saturated nucleate pool boiling of binary mixtures of water and glycerin at atmospheric pressure in a wide range of concentrations and heat fluxes. Mixtures with water mass fractions from 100% to 40% were boiled on a horizontal flat copper surface at heat fluxes from about 25 up to 270kWm−2. Experiments were carried out by static and dynamic method of measurement. Results of the static method show that the impact of mixture effects on heat transfer coefficient cannot be neglected and ideal heat transfer coefficient has to be corrected for all investigated concentrations and heat fluxes. Experimental data are correlated with the empirical correlation α=0.59q0.714+0.130ωw with mean relative error of 6%. Taking mixture effects into account, data are also successfully correlated with the combination of Stephan and Abdelsalam (1980) and Schlünder (1982) correlations with mean relative error of about 15%. Recommended coefficients of Schlünder correlation C0=1 and βL=2×10−4ms−1 were found to be acceptable for all investigated mixtures. The dynamic method was developed for fast measurement of heat transfer coefficients at continuous change of composition of boiling mixture. The dynamic method was tested for water–glycerin mixtures with water mass fractions from 70% down to 35%. Results of the dynamic method were found to be comparable with the static method. For water–glycerin mixtures with higher water mass fractions, precise temperature measurements are needed.

scholarly journals Rapid water parcel transport across the Kuroshio Extension in the lower thermocline from dissolved oxygen measurements by Seaglider

2020 ◽  
Author(s):  
Shigeki Hosoda ◽  
Ryuichiro Inoue ◽  
Masami Nonaka ◽  
Hideharu Sasaki ◽  
Yoshikazu Sasai ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Dissolved Oxygen ◽  
Water Mass ◽  
Kuroshio Extension ◽  
Exchange Process ◽  
Surrounding Water ◽  
Small Water ◽  
Low Salinity ◽  
Mass Migration ◽  
The Kuroshio

Abstract Small water parcels with low salinity and high dissolved oxygen (DO) are observed in the main thermocline south of the Kuroshio Extension (KE). The Seaglider data, which was collected for four months beginning in late winter 2014 with fine spatial and temporal resolutions, identified small water parcels characterized by low salinity and high DO in the subsurface layer (26.0–27.0 σθ) with a few ten kilometers and a few ten meters in the horizontal and vertical scales, respectively. Water mass analyses revealed larger negative salinity anomalies (< − 0.05 PSS-78) and positive DO anomalies (> 15 µmol kg− 1) than those of the surrounding water. The characteristics are similar to those of water mass with low salinity and high DO in the subpolar Northwestern Pacific Ocean. Additionally, higher DO anomaly water parcels appear in the upper layer (< 26.7 σθ) while low salinity parcels appear in the lower layer (> 26.7 σθ). Oxygen consumption rates from the apparent oxygen utility suggest that the small water parcels consume less oxygen than the surrounding water, implying that they migrate in a shorter time across the KE after subduction and their characteristics may reflect the sea surface temperature, salinity, and DO in the subduction region. Similar small water parcels represented by high-resolution numerical simulations indicate that they pass through the KE in one month. The simulations support the oxygen consumption rate from the Seaglider observations. The existence of a faster process for water mass migration by meso- and submesoscale subduction processes across the KE affects the amount, subduction, and exchange process of water mass. Our study indicates a small water mass contributes to the exchange process across the KE rapidly, which had not been identified in previous studies. Consequently, detailed observations using multiple Seagliders should capture detailed spatial and temporal variability of the water mass exchange process.

Tracing water mass fractions in the deep western Indian Ocean using fluorescent dissolved organic matter

2020 ◽  
Vol 218 ◽  
pp. 103720 ◽  
Author(s):  
Jeonghyun Kim ◽  
Yeseul Kim ◽  
Hyoun-Woo Kang ◽  
Suk Hyun Kim ◽  
TaeKeun Rho ◽  
...  
Keyword(s):  
Organic Matter ◽  
Indian Ocean ◽  
Dissolved Organic Matter ◽  
Water Mass ◽  
Western Indian Ocean ◽  
Fluorescent Dissolved Organic Matter ◽  
Mass Fractions

scholarly journals The nature of the TRAPPIST-1 exoplanets

2018 ◽  
Vol 613 ◽  
pp. A68 ◽  
Author(s):  
Simon L. Grimm ◽  
Brice-Olivier Demory ◽  
Michaël Gillon ◽  
Caroline Dorn ◽  
Eric Agol ◽  
...  
Keyword(s):  
Genetic Algorithm ◽  
Parameter Space ◽  
Water Mass ◽  
Inversion Problem ◽  
Dwarf Star ◽  
Mass Fractions ◽  
Novel Method ◽  
Formation And Evolution ◽  
Bulk Structure ◽  
Better Than

Context. The TRAPPIST-1 system hosts seven Earth-sized, temperate exoplanets orbiting an ultra-cool dwarf star. As such, it represents a remarkable setting to study the formation and evolution of terrestrial planets that formed in the same protoplanetary disk. While the sizes of the TRAPPIST-1 planets are all known to better than 5% precision, their densities have significant uncertainties (between 28% and 95%) because of poor constraints on the planet’s masses. Aims. The goal of this paper is to improve our knowledge of the TRAPPIST-1 planetary masses and densities using transit-timing variations (TTVs). The complexity of the TTV inversion problem is known to be particularly acute in multi-planetary systems (convergence issues, degeneracies and size of the parameter space), especially for resonant chain systems such as TRAPPIST-1. Methods. To overcome these challenges, we have used a novel method that employs a genetic algorithm coupled to a full N-body integrator that we applied to a set of 284 individual transit timings. This approach enables us to efficiently explore the parameter space and to derive reliable masses and densities from TTVs for all seven planets. Results. Our new masses result in a five- to eight-fold improvement on the planetary density uncertainties, with precisions ranging from 5% to 12%. These updated values provide new insights into the bulk structure of the TRAPPIST-1 planets. We find that TRAPPIST-1 c and e likely have largely rocky interiors, while planets b, d, f, g, and h require envelopes of volatiles in the form of thick atmospheres, oceans, or ice, in most cases with water mass fractions less than 5%.

scholarly journals Service connections of the Katowice conurbation cities

2019 ◽  
Vol 7 (4) ◽  
pp. 17-25
Author(s):  
Franciszek Kłosowski
Keyword(s):  
Place Of Residence ◽  
Limited Impact ◽  
Service Areas ◽  
The Impact ◽  
Do So

Abstract The study attempts to determine the service connections of the cities of the Katowice conurbation. The analysis was based on surveys conducted among 845 residents representing all cities in the conurbation, who were asked about using services in other cities. The collected material allowed the author to state that the practice of using services outside their place of residence, in other cities, is quite common, as 63% of respondents do so. The cities of the conurbation have a different impact on other centres, which allowed us to determine the service hierarchy of the conurbation cities. In all but one city, the inhabitants most often indicated that they used services located in Katowice, thus as the only city used this has an impact covering the entire Katowice conurbation. Seven other cities (Bytom, Chorzów, Dąbrowa Górnicza, Gliwice, Sosnowiec, Tychy and Zabrze) demonstrate sub-conurbation influences, which are mainly limited to neighbouring cities. The impact of cities within a mini-conurbation (4 cities) and a micro-conurbation (5 cities) were also identified. These have a limited impact on neighbouring centres, but, only in selected service areas. The collected information indicates that the inhabitants of the conurbation most often go to another city for commercial and cultural purposes and in connection with practising sports and recreation.

scholarly journals Rapid water parcel transport across the Kuroshio Extension in the lower thermocline from dissolved oxygen measurements by Seaglider

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Shigeki Hosoda ◽  
Ryuichiro Inoue ◽  
Masami Nonaka ◽  
Hideharu Sasaki ◽  
Yoshikazu Sasai ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Dissolved Oxygen ◽  
Water Mass ◽  
Kuroshio Extension ◽  
Exchange Process ◽  
Surrounding Water ◽  
Small Water ◽  
Low Salinity ◽  
Mass Migration ◽  
The Kuroshio

AbstractSmall water parcels, which are characterized by a low salinity and high dissolved oxygen (DO) are observed by Seaglider in the main thermocline (26.0–27.0 σθ) south of the Kuroshio Extension (KE), have horizontal and vertical scales of a few tens of kilometers and a few tens of meters, respectively. Water mass analyses revealed larger negative salinity anomalies (<− 0.05) and positive DO anomalies (> 15 μmol kg−1) than those of the surrounding water. The characteristics are similar to those of water mass with low salinity and high DO in the subpolar Northwestern Pacific Ocean. Additionally, higher DO anomaly water parcels appear in the upper layer (< 26.7 σθ) while low salinity parcels appear in the lower layer (> 26.7 σθ). Oxygen consumption rates from the apparent oxygen utility suggest that the small water parcels consume less oxygen than the surrounding water, implying that they migrate in a shorter time across the KE after subduction and their characteristics may reflect the sea surface temperature, salinity, and DO in the subduction region. Similar small water parcels represented by high-resolution numerical simulations indicate that they pass through the KE in 1 month. The simulations support the oxygen consumption rate from the Seaglider observations. The existence of a fast process for water mass migration via meso- and submesoscale subduction processes across the KE affects the amount, subduction, and exchange process of water mass. Our study indicates that a small water mass contributes to the exchange process across the KE rapidly, which had not been identified in previous studies. Consequently, detailed observations using multiple Seagliders should capture detailed spatial and temporal variability of the water mass exchange process.

An Experimental Study of Choked Flow in Short Pipes With Low Air Water Mass Fractions

1977 ◽  
Vol 99 (2) ◽  
pp. 421-423 ◽  
Author(s):  
V. Ilic ◽  
R. A. A. Bryant
Keyword(s):  
Atmospheric Pressure ◽  
Water Mass ◽  
Pressure Variation ◽  
Appreciable Effect ◽  
Water Mixture ◽  
Choked Flow ◽  
The Core ◽  
Flow Parameters ◽  
Mass Fractions ◽  
Low Mass

Using steady flow of air/water at low mass ratios, choking was obtained in short pipes by reducing the back pressure well below atmospheric pressure. Variation of flow parameters affected the choked mass flow-rate, but showed no appreciable effect on the flow pattern; this remained annular with air/water mixture on the outside and water in the core of the pipe.

scholarly journals On the importance of including devolatilized stellar abundances in determining the composition of rocky exoplanets

2021 ◽  
Author(s):  
Fabian Seidler ◽  
Haiyang Wang ◽  
Sascha Quanz
Keyword(s):  
Mass Fraction ◽  
Terrestrial Planets ◽  
Chemical Compositions ◽  
Posterior Distributions ◽  
Stellar Abundances ◽  
Core Mass ◽  
The Core ◽  
Planetary Mass ◽  
Before And After ◽  
Mass Fractions

&lt;p&gt;Since stars and their planets form from the same molecular clouds, stellar chemical composition can be informative, to first order, of planetary bulk chemistry. An important feature of terrestrial planets compared to their host stars is the depletion of volatiles, the most important being oxygen. Previous studies on planet interiors focus on the mass and radius constraints and/or the host stellar refractory elements (e.g. Fe, Si and Mg), neglecting devolatilisation and its impact on the final picture of planet mineralogy and structure. This work assesses to what extent the devolatilised stellar abundances reflect rocky planetary composition.&amp;#160;&amp;#160;&lt;/p&gt;&lt;p&gt;We firstly test how the uncertainties associated with planetary mass and radius would affect the modelling results of core mass fraction &amp;#8211; an important interior parameter. To do so, we choose the Sun-like star Kepler-21 (stellar abundance uncertainties &lt;0.05 dex) as a case study and assume it hosts an Earth-mass-and-radius planet in its habitable zone. We then assign different levels of uncertainties to the mass and radius of the hypothetical planet, ranging from 0.1% to 20%. We find that with increasing uncertainty level, the modelling result of core mass fraction constrained by the devolatilised stellar abundances and mass and radius becomes identical with the core mass fraction constrained purely by the devolatilised stellar abundances. This reveals the increased modelling degeneracy with growing uncertainties in mass and radius measurements, but also the strong constraints placed by using the devolatilised stellar abundances.&lt;/p&gt;&lt;p&gt;We further investigate a sample of 12 confirmed exoplanets, which are all less than 10 Earth masses and 2 Earth radii &amp;#8211; i.e. potentially terrestrial planets or super-Earths &amp;#8211; and with the measured uncertainties in mass and radius respectively less than 35% and 10%. By comparing the prior and posterior distributions of mass and radius before and after introducing the devolatilised stellar abundances as another prior, we find that the posterior distributions of all samples, but 55 Cnc e and Kepler-107 c, can be sampled within the 2&amp;#963; ranges of the prior distributions. For the two exceptional cases, it means that the devolatilised stellar abundances and the measured mass and radius are not compatible within the level of 2&amp;#963;.&lt;/p&gt;&lt;p&gt;We also find a diverse distribution of the core mass fractions of the sample from 0% (i.e. coreless) up to 40%, which are consistent at the 2&amp;#963; level &amp;#61472;with the core mass fractions purely constrained by mass and radius measurements (except Kepler-107 c and 55 Cnc e),&amp;#160; but are significantly constrained by adding the devolatilized stellar abundances. In contrast, the previous study for the similar sample shows nearly constant core mass fractions of ~ 30% based on the unaltered stellar abundances and by assuming 100% Fe sunk into the core (i.e. free of consideration of the oxidation state of the planets). We emphasise that to break the degeneracies of terrestrial-type exoplanet interior modelling, we must use well the currently available observables including planetary mass and radius and host stellar chemical compositions, but they must be viewed through the lens of planet formation&amp;#160; and the resulting devolatilization.&lt;/p&gt;

scholarly journals Rapid water parcel transport across the Kuroshio Extension in the lower thermocline from dissolved oxygen measurements by Seaglider

2021 ◽  
Author(s):  
Shigeki Hosoda ◽  
Ryuichiro Inoue ◽  
Masami Nonaka ◽  
Hideharu Sasaki ◽  
Yoshikazu Sasai ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Dissolved Oxygen ◽  
Water Mass ◽  
Kuroshio Extension ◽  
Exchange Process ◽  
Surrounding Water ◽  
Small Water ◽  
Low Salinity ◽  
Mass Migration ◽  
The Kuroshio

Abstract Small water parcels, which are characterized by a low salinity and high dissolved oxygen (DO) are observed by Seaglider in the main thermocline (26.0–27.0 sq) south of the Kuroshio Extension (KE), have horizontal and vertical scales of a few ten kilometers and a few ten meters, respectively. Water mass analyses revealed larger negative salinity anomalies (<−0.05) and positive DO anomalies (>15 μmol kg−1) than those of the surrounding water. The characteristics are similar to those of water mass with low salinity and high DO in the subpolar Northwestern Pacific Ocean. Additionally, higher DO anomaly water parcels appear in the upper layer (<26.7 σθ) while low salinity parcels appear in the lower layer (>26.7 sq). Oxygen consumption rates from the apparent oxygen utility suggest that the small water parcels consume less oxygen than the surrounding water, implying that they migrate in a shorter time across the KE after subduction and their characteristics may reflect the sea surface temperature, salinity, and DO in the subduction region. Similar small water parcels represented by high-resolution numerical simulations indicate that they pass through the KE in one month. The simulations support the oxygen consumption rate from the Seaglider observations. The existence of a fast process for water mass migration via meso- and submesoscale subduction processes across the KE affects the amount, subduction, and exchange process of water mass. Our study indicates a small water mass contributes to the exchange process across the KE rapidly, which had not been identified in previous studies. Consequently, detailed observations using multiple Seagliders should capture detailed spatial and temporal variability of the water mass exchange process.

Sign in / Sign up

Export Citation Format

Share Document