Greenland Geothermal Heat Flow Database and Map (Version 1)

We compile, analyse and map all available geothermal heat flow measurements collected in and around Greenland into a new database of 419 sites and generate an accompanying spatial map. This database includes 290 sites previously reported by the International Heat Flow Commission (IHFC), for which we now standardize measurement and metadata quality. This database also includes 129 new sites, which have not been previously reported by the IHFC. These new sites consist of 88 offshore measurements and 41 onshore measurements, of which 24 are subglacial. We employ machine learning to synthesize these in situ measurements into a gridded geothermal heat flow model that is consistent across both continental and marine areas in and around Greenland. This model has a native horizontal resolution of 55 km. In comparison to five existing Greenland geothermal heat flow models, our model has the lowest mean geothermal heat flow for Greenland onshore areas (44 mW m–2). Our model’s most distinctive spatial feature is pronounced low geothermal heat flow (< 40 mW m–2) across the North Atlantic Craton of southern Greenland. Crucially, our model does not show an area of elevated heat flow that might be interpreted as remnant from the Icelandic Plume track. Finally, we discuss the substantial influence of paleoclimatic and other corrections on geothermal heat flow measurements in Greenland. The in-situ measurement database and gridded heat flow model, as well as other supporting materials, are freely available from the GEUS DataVerse (https://doi.org/10.22008/FK2/F9P03L; Colgan and Wansing, 2021).

Input data automation to model evaporation loss in an Argentinian vineyard using a coupled water, vapor and heat flow model

&lt;p&gt;Water resources in arid regions around the world are under a lot of strain due to extremely low precipitation rates and very high evaporation. In addition to water scarcity, irrigation methods can be quite inefficient. For example, over-irrigation beyond soil saturation can cause many problems, such as increase in soil salinity and decrease in productive soil capacity.&lt;br&gt;&lt;br&gt;This research aims to investigate evaporation losses in a vineyard in San Juan province, Argentina. Trucks are used to deliver irrigation water to the raisin-producing vineyard, which ends up being over-flooded due to poor irrigation schedules, making the process highly costly.&lt;br&gt;For the estimation of evaporation losses, we use a coupled water, vapor, and heat flow model implemented in DRUtES software, Kuraz and Bl&amp;#246;cher (2020). The model&amp;#8217;s top boundary condition solves the surface energy balance. For that we need the solar radiation as input, which we compute based on equations suggested in the FAO Irrigation and Drainage guideline No. 56 and by Saito et al. (2006).&lt;/p&gt;&lt;p&gt;Due to the lack of measurement data &amp;#160;on the study site, soil hydraulic and thermal properties are estimated. We neglect the effect of soil organic matter in the water retention model &amp;#160;and assume a homogenous type of soil for the thermodynamic model. While climatic data is available from a nearby meteorological station, access to backdated files is not possible. This limits our choice of simulation period. To solve this issue, we create Python codes that produce automated daily procedures to access the weather servers. This transcribed data record is then used as input for DRUtES configuration files. We also establish communication with sensors installed in the soil using Python-script automation, in order to rectify missing measurements and use them as the model&amp;#8217;s initial conditions.&lt;/p&gt;&lt;p&gt;The result is output records that simulate pressure heads and water content distribution across the flow field over the simulated period. We present a system that describes the flow field allowing us to calculate evaporation rate changes with time, thereby optimizing the irrigation process according to soil and plant needs. This can be a helpful decision-making tool for farmers.&lt;/p&gt;

Heat flow model based on lattice Boltzmann method for modeling of heat transfer during phase transformation

Purpose A fundamental principle of materials engineering is that the microstructure of a material controls the properties. The phase transformation is an important phenomenon that determines the final microstructure. Recently, many analytical and numerical methods were used for modeling of phase transformation, but some limitations can be seen in relation to the choice of the shape of growing grains, introduction of varying grain growth rate and modeling of diffusion phenomena. There are also only few comprehensive studies that combine the final microstructure with the actual conditions of its formation. Therefore, the objective of the work is a development of a new hybrid model based on lattice Boltzmann method (LBM) and cellular automata (CA) for modeling of the diffusional phase transformations. The model has a modular structure and simulates three basic phenomena: carbon diffusion, heat flow and phase transformation. The purpose of this study is to develop a model of heat flow with consideration of enthalpy of transformation as one of the most important parts of the proposed new hybrid model. This is one of the stages in the development of the complex model, and the obtained results will be used in a combined solution of heat flow and carbon diffusion during the modeling of diffusion phase transformations. Design/methodology/approach Different values of overheating/overcooling affect different values in the enthalpy of transformation and thus the rate of transformation. CA and LBM are used in the hybrid model in part related to heat flow. LBM is used for modeling of heat flow, while CA is used for modeling of the microstructure evolution during the phase transformation. Findings The use of LBM and CA in one numerical solution creates completely new possibilities for modeling of phase transformations. CA and LBM in comparison with commonly used approaches significantly simplify interface and interaction between different parts of the model, which operates in a common domain. The CA can be used practically for all possible processes that consist of nucleation and grains growth. The advantages of the LBM method can be well used for the simulation of heat flow during the transformation, which is confirmed by numerical results. Practical implications The developed heat flow model will be combined with the carbon diffusion model at the next stage of work, and the new complex hybrid model at the final stage will provide new solutions in numerical simulation of phase transformations and will allow comprehensive modeling of the diffusional phase transformations in many processes. Heating, annealing and cooling can be considered. Originality/value The paper presents the developed model of heat flow (temperature module), which is one of the main parts of the new hybrid model devoted to modeling of phase transformation. The model takes into account the enthalpy of transformation, and the connection with the model of microstructure evolution was obtained.

Anti-Icing and De-Icing of Pipe Structures on Marine Vessels Using Waste Heat Recovery

One of the major challenges for a ship sailing in Arctic waters is ice aggregation. Atmospheric water or sea spray that comes into contact with the cold railing, equipment and superstructure deposits ice on the exposed surfaces. This ice can build up over time to such an extend, that the weight of the ice can severely impair the ships stability, even lead to capsizing. To prevent such accidents, the IMO Polar Code for ships operating in Arctic areas requires countermeasures against icing. Ulmatec Pyro has developed a “double pipe system” that makes use of waste heat, recovered from the ships propulsion and energy system. The main objective of this research project has been to investigate the behavior of anti-icing and de-icing for pipe structures to provide design rules and operational guidelines for such systems. Pipe systems have been studied using both numerical and experimental methods. First a simple 1D pipe system, simulating the steady heat transfer with a finite difference method, was implemented. The purpose of this model is was to be able to quickly study design variations. Next, a more advanced 3D axis-symmetric heat flow model was simulated, using a commercial transient finite element solver. The results of the advanced model was used to evaluate the simple model. Subsequently these simulation tools were used to support the design decisions for the experimental setup. To get the IMO approval for the double pipe system, the experiments were conducted at the site of the classification society. The experimental setup was used to validate the simulation model, and furthermore as a design verification lab for Ulmatec Pyro. A comparison of the results between both numerical simulation models and experiments show a good correlation. In addition, the experiments provide a valuable insight into the icing- and anti-icing processes. Specifically, a better understanding of the complex ice melting process.

A new spatially continuous basement heat flow map for NW Queensland

A recently released open file study of the depth-to-basement and basement heat flow is presented, which covers the Queensland portion of the South Nicholson Basin and includes basins underlying the Lawn Hill Platform and Georgina Basin. The present-day basement heat flow model is derived from an analysis of basement composition, structure and history, with the crustal radiogenic and mantle heat flow assessed separately. Resulting from an integrated, iterative interpretation and analysis of a wide range of publicly available spatially continuous geophysical and geological datasets, the heat flow model reproduces faithfully sharp and high-amplitude variations of the published heat flow at small distances. Variations are replicated through the integration of interpreted basement composition and a geologically driven determination of heat production within the radiogenic crustal layer. The values of mantle heat flow based on lithosphere thickness derived from seismic tomography models are consistent with published stable mantle heat flow under terranes of similar age. The long-wavelength regional variations can be attributed to the change in the thickness of the lithosphere. Regionally, the highest values of heat flow are found where radiogenic crust is the thickest and the composition is interpreted to comprise radiogenic intrusives.