Low Temperature Field Research Articles

Genesis of the Xifeng Low-Temperature Geothermal Field, Guizhou, SW China: Constrains From Geology, Element Geochemistry, and D-O Isotopes

The Xifeng geothermal field is located in the Yangtze Craton, SW China, and is one of the most representative low-temperature geothermal fields in China. Widespread thermal anomalies, hot springs, and geothermal wells have been reported by previous studies. However, the nature and forming mechanisms of the field remain poorly understood. Element geochemical (ions, rare earth elements) and stable isotopic (D, O) composition of hot springs, geothermal fluids, rivers, and cold springs from different locations of the Xifeng geothermal field were analyzed in this study. The ions studies revealed that most samples featured the Ca-Mg-HCO3 type, except Xifeng hot springs, and which were characterized by the Ca-Mg-HCO3-SO4 type. Based on quartz geothermometers, the estimated reservoir temperature was 77°C. The results of stable isotopes (D, O) manifest that the Xifeng geothermal system was recharged by meteoric water at an elevation of 1,583 m from SW to NE. The research of rare earth elements (REE) revealed that their accumulation characteristics and obvious positive Eu anomaly were inherited from host feldspar-bearing reservoir dolomites through water-rock interactions. Combined with these observations, geological setting, and previous studies, it was concluded that the formation of the Xifeng geothermal field resulted from recharge, deep circulation, and secondary rising of the meteoric water along the faults. First, meteoric water infiltrated to depth through faults and crack zones. Second, the deep-infiltrated water was heated by radioactive heat, deep heat, and tectonic frictional heat. Finally, as the warmed-up waters underwent considerable deep circulation in the reservoir, it rose again along the main faults, and mixed with groundwater near the surface. Taken together, we suggest that the Xifeng geothermal system should be assigned as a faults-controlling, and deeply circulating meteoric water of low-temperature category.

Development of high-resolution capacitive Faraday magnetometers for sub-Kelvin region.

High-sensitivity capacitive Faraday magnetometers were developed for static DC magnetization measurements in a sub-Kelvin region that can be used with 3He-4He dilution refrigerators (∼50 mK) and 3He refrigerators (∼0.28K). For high-resolution magnetization measurements, the background magnetization of the force-sensing capacitor should be as small as possible, compared with the magnetization value of a measured specimen. In this study, we succeeded in reducing the background of the capacitor in both low- and high-field regions by compensating for the diamagnetic response of a thin quartz plate, making use of Pauli-paramagnetic alloys and Van Vleck paramagnets as a counter magnetization for a diamagnetic signal. Having established an ultra-high-sensitivity capacitor, we achieved a resolution of 10-5 (∼10-5-10-6) emu in the low- (high-) field region below (above) 1T. In particular, the newly developed capacitors with a Van Vleck paramagnet Pr0.1La0.9Be13 and paramagnetic MgAl alloys are demonstrated to be very useful for high-resolution magnetization measurements at milli-Kelvin temperatures in low and high magnetic fields, respectively.

Effects of Magnetic Fields in Hot White Dwarfs

Abstract In this work, we study the effects of magnetic fields on hot white dwarfs. We model their interior as a nuclei lattice surrounded by a relativistic free Fermi gas of electrons, accounting for effects from temperature, Landau levels, and anomalous magnetic moment. We find that, at low densities (corresponding to the outer regions of star), both temperature and magnetic field effects play an important role in the calculation of microscopic thermodynamical quantities. To study macroscopic stellar structures within a general-relativistic approach, we numerically solve the coupled Einstein–Maxwell equations for fixed entropy per particle configurations and discuss how temperature affects stellar magnetic field profiles, masses, and radii.

Comparative investigation on copper atmospheric corrosion by electrochemical impedance and electrical resistance sensors

Electrochemical impedance (EIS) and thin electrical resistance (ER) sensors were invented for atmospheric corrosion measurement of copper (Cu) during cyclic wetting–drying/high–low temperature tests and field exposure tests. Three-month field exposure results showed that average corrosion rate of Cu measured by ER sensor was well in accordance with that by weight loss method. During cyclic wetting–drying test, EIS was proven to reflect sensitively time of wetting and drying on the surface of sensor. Although corrosion rate obtained from EIS had a similar tendency to that obtained from ER sensors, the former was more dependent on environmental humidity than the latter. When relative humidity was low than 60%, corrosion rate of Cu measured by EIS was much lower than that by weight loss method, mainly attributing to the fact that impedance sensor failed to detect corrosion current of interlaced Cu electrodes due to the breakdown of conductive passage composed of absorbed thin liquid film under low humidity condition. Promisingly, ER sensor was proven to be more suitable for atmospheric corrosion monitoring than electrochemical techniques because it could sensitively monitor thickness loss of Cu foil according to the Ohmic law, no matter how dry or wet the sensor surface is.

Induced Polarization as a Tool to Assess Alteration in Geothermal Systems: A Review

The mineral alteration patterns in high- to low-temperature geothermal fields affect the induced polarization (electrical conductivity and chargeability) properties of volcanic rocks. Indeed, these properties are sensitive to the cation exchange capacity and the porosity of the rock, which are both dependent on the alteration path, temperature, and depth of burial. Therefore induced polarization tomography appears as a powerful non-intrusive geophysical method to investigate alteration patterns in geothermal fields. Among clay minerals, the production of smectite through prograde reactions occurs progressively in volcanic rocks up to 220 °C. The presence of smectite dominates the induced polarization response of the volcanic rocks because of its very large cation exchange capacity. It follows that induced polarization can be used as a non-intrusive temperature proxy up to 220 °C for both active and inactive geothermal fields, recording the highest temperatures reached in the past. The influence of magnetite and pyrite, two semi-conductors, also has a strong influence regarding the induced polarization properties of volcanic rocks. Various field examples are discussed to show how induced polarization can be used to image volcanic conduits and smectite-rich clay caps in volcanic areas for both stratovolcanoes and shield volcanoes.

A numerical approach to verify the reservoir temperature of the Afyon geothermal fields, Turkey

Geothermal energy constitutes an important renewable resource in Turkey that has been extensively utilized for heating buildings, power generation, greenhouse farming and various other industries. One of the most remarkable geothermal locations in Turkey is the low-enthalpy area of Afyon, where five main low-temperature (30-110 °C) geothermal fields are exploited. However, further exploration drilling sites have proven inconclusive, casting doubts on the effective presence of high-temperature geothermal systems in the region. Part of the challenge is that the geometry, size and depth of the heat source of the geothermal system is poorly constrained. It is documented that the Afyon region hosts voluminous and well-preserved potassic/ultrapotassic volcanic successions that formed between 15 and 8 Ma. It is also well known that volcanoes are fed by magma chambers and reservoirs which can be linked to fault zones and geothermal systems. In this study, the origin of the geothermal systems in Afyon is explored by considering the maximum recorded well-head temperature of 110 °C and the estimated reservoir temperature of 125 °C from hydrochemistry data. The calculated and measured temperatures are interpreted in terms of thermal finite element method models.Various thermal models illustrate the possible temperature distribution throughout the crust assuming an arrangement of a crustal magma chamber and a geothermal gradient of 30 °C/km. Results show that the temperature of the fluids at the measured well-head temperature of 110 °C, or estimated reservoir temperature of 125 °C, require the presence of a magma chamber with a temperature in the range 600-800 °C at a depth of 5-7.5 km. These two-dimensional models that simulate crustal geothermal gradients can be used with suitable modifications, to advance the understanding of other geothermal fields.

Appraising Mahallat Geothermal Region using thermal surveying data accompanied by the geological, geochemical and gravity analyses

Mahallat Geothermal Region, located in the central part of Iran, is known as one of the largest low-temperature geothermal fields. In this study, Mahallat geothermal resource has been evaluated based on integrated geological, geochemical and geophysical analyses. Gravity data revealed three major negative anomaly zones. Based on the geochemical analyses, quartz geothermometers are more reliable than others and confirmed that the reservoir is about 90 °C. Lithological properties of Jurassic layers and high sulphate content observed in geochemical data showed traces of the coal-rich layers on the hot fluids. Measured temperatures in 7 boreholes with the depths ranging from 50 to 100 m, have proposed that expected geothermal gradient will be about 81.5 °C/km. Among all drilled boreholes, the data coming from only one resulted in this almost reliable gradient. Other boreholes are clearly too shallow or affected by upflow or downflow of water along existing faults. Geological, geochemical, gravity and measurements of drilled boreholes suggested the existence of a shallow reservoir with an approximate temperature of 90 °C. Regarding gravity and observed faults, geothermal reservoir is elongated parallel to one of the main faults of the region with NE-SW strike.

Cyclic cooling of quantum systems at the saturation limit

The achievable bounds of cooling quantum systems, and the possibility to violate them is not well-explored experimentally. For example, among the common methods to enhance spin polarization (cooling), one utilizes the low temperature and high-magnetic field condition or employs a resonant exchange with highly polarized spins. The achievable polarization, in such cases, is bounded either by Boltzmann distribution or by energy conservation. Heat-bath algorithmic cooling schemes (HBAC), on the other hand, have shown the possibility to surpass the physical limit set by the energy conservation and achieve a higher saturation limit in spin cooling. Despite, the huge theoretical progress, and few principle demonstrations, neither the existence of the limit nor its application in cooling quantum systems towards the maximum achievable limit have been experimentally verified. Here, we show the experimental saturation of the HBAC limit for single nuclear spins, beyond any available polarization in solid-state spin system, the Nitrogen-Vacancy centers in diamond. We benchmark the performance of our experiment over a range of variable reset polarizations (bath temperatures), and discuss the role of quantum coherence in HBAC.

Thermodynamic evidence for the formation of a Fulde-Ferrell-Larkin-Ovchinnikov phase in the organic superconductor λ−(BETS)2GaCl4

In this work, the thermodynamic properties of the organic superconductor $\lambda$-(BETS)$_2$GaCl$_4$ are investigated to study a high-field superconducting state known as the putative Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase. We observed a small thermodynamic anomaly in the field $H_{\rm FFLO}$ $\sim$ 10~T, which corresponds to the Pauli limiting field $H_{\rm P}$. This anomaly probably originates from a transition from a uniform superconducting state to the FFLO state. $H_{\rm FFLO}$ does not show a strong field-angular dependence due to a quasi-isotropic paramagnetic effect in $\lambda$-(BETS)$_2$GaCl$_4$. The thermodynamic anomaly at $H_{\rm FFLO}$ is smeared out and low-temperature upper critical field $H_{\rm c2}$ changes significantly if fields are not parallel to the conducting plane even for a deviation of $\sim$0.5$^{\circ}$. This behavior indicates that the high-field state is very unstable, as it is influenced by the strongly anisotropic orbital effect. Our results are consistent with the theoretical predictions on the FFLO state, and show that the high-field superconductivity is probably an FFLO state in $\lambda$-(BETS)$_2$GaCl$_4$ from a thermodynamic point of view.

Thermorheological properties of magnetorheological grease and its thermomagnetic coupling mechanism

A heating phenomenon exists in the service process of magneto-rheological devices. For magnetorheological devices using magnetorheological grease (MRG) as the working medium, changes in the medium’s rheological behaviors caused by temperature increase will generate challenges in the reliable service of the devices. With laboratory-prepared MRG as the research object, MRG rheological property laws under different temperatures and magnetic field intensities are investigated, and the magnetic properties of carbonyl iron (CI) powder under different temperatures are analyzed. The relationship between the evolution of the MRG structural system and changes in rheological properties under the action of thermomagnetic coupling is discussed. The results show that the MRG structural system is composed of base carrier liquid soap fibers and magnetic chains under the action of a magnetic field, and the soap fibers can strengthen the structural intensity of the MRG. A decrease in the entanglement degree of the soap fiber structure caused by temperature increase will obviously weaken the intensity of the entire MRG system and narrow the regulation and control scope of the MRG rheological properties. The structural evolution of soap fibers under thermomagnetic coupling will affect the chain formation of magnetic particles and ultimately their rheological properties. At low temperature and magnetic field intensity, the entanglement degree of soap fibers is relatively high, and the magnetic force on magnetic particles is weak, which cannot completely overcome the binding of soap fibers. The influence of soap fibers is the dominant factor affecting the MRG rheological properties. As temperature and magnetic field intensity increase, the entanglement degree of soap fibers decreases, magnetic particles gradually disperse from the soap fibers under the action of a large magnetic field force, and the magnetic chain structure gradually becomes the dominant factor affecting the MRG rheological properties. Moreover, the weakening degree of the temperature increase effect on the MRG rheological properties decreases, and the rheological law changes gradually.

The IR-FEL facility at RRCAT: Commissioning experiments and first saturation of lasing at [formula omitted] wavelength

An Infrared Free Electron Laser (IR-FEL) has been designed and developed at RRCAT for potential use in the IR/THz spectroscopy of materials in low temperature and high magnetic field environment. The first commissioning experiments on the IR-FEL setup were performed in 2016, but the out-coupled power achieved in these experiments was two to three orders of magnitude lower than the saturated out-coupled power predicted by the FEL design simulations, mainly due to certain limitations in its injector system. The setup has recently undergone a major upgrade with the installation and commissioning of a new injector system, and lasing at a wavelength of 28μm has recently been observed in the setup. This is the first saturation of lasing of an FEL in India, with a measured Continuous Wave (CW) out-coupled IR power of 5 - 7.3 mW. This paper discusses the present status of the IR-FEL project at RRCAT, and the results from recent commissioning experiments leading to lasing in the setup.

A comparative study of the physical properties of Pr0.63La0.37−xSrxMnO3 (xSr = 0.00–0.30) characterized by “λ” shape dc magnetizations

Magnetic, morphological, and physical properties of Pr0.63La0.37−xSrxMnO3 (xSr = 0.00, 0.05, 0.10, 0.15, 0.20, and 0.30) magnetic nanoparticles have been studied experimentally based on the evolution of the amount of Sr in these systems and by heat treatment. A solid-state reaction method was used to prepare the samples. The microstructure of the samples was determined by scanning electron microscopy. Three sets of Sr-doped manganites of the perovskite family Pr0.63La0.37−xSrxMnO3 nanoparticles were heated at three different temperatures, i.e., 500, 700, and 800 °C. X-ray data showed that all compounds in the cubic space group Fd-3m crystallized. Field-cooled and zero-field-cooled thermomagnetic curves measured at low field and low temperatures showed that systems have different magnetic states, varying from superparamagnetic, ferromagnetic to paramagnetic states, with charge ordering behavior present in some prepared systems. The maximum entropy change of the xSr-800°C = 0.05 sample reached the highest value of refrigerant capacity compared to other systems in a magnetic field with 17.278 J/kg at 1 T and 208.264 J/kg at 7 T.

Force Characteristic Analysis of Different Steel Deck Pavement under Temperature Load Coupling Situation

In order to investigate the force characteristic of different steel deck pavement under extreme temperature and load coupling situation, we established the three dimensional extreme high temperature and extreme low temperature field of simple supported beam bridge, the paving structure were double layered SMA, double layered epoxy concrete, SMA+GA, using material elastic modulus changing with temperature. Analysis indicated that the maximum value of high temperature normal stress occurred in the epoxy upper layer pavement, the maximum value of shear stress occurred in the epoxy lower layer pavement, the maximum value of high temperature strain occurred in the upper layer of double layered SMA pavement. The maximum value of low temperature stress occurred in the SMA+GA lower layer pavement, the maximum value of low temperature strain occurred in the SMA+GA upper layer pavement, the maximum value of shear strain occurred in the SMA lower layer pavement. The maximum value of high temperature stress usually occurred in the bottom of pavement layer, maximum strain usually occurred on top of pavement layer. The maximum value of low temperature shear stress and shear strain usually occurred in the bottom of pavement layer, normal strain occurred on top of pavement layer. The stress difference between the upper and lower layers in SMA+GA pavement structure is very large which adversely affected the structural force.

Effect of Nano-Size Magnetic Additions on Low Temperature Flux Pinning of Y-Ba-Cu-O Thin Films

Manufacturing of coated conductors can be tailored for future use operating parameters, such as high temperature and low field, mid temperature and mid field and low temperature and high field. Different methods of flux pinning are being tested world-wide to enhance critical currents of high temperature superconductor yttrium barium copper oxide coated conductors for these various operating conditions. Magnetic materials are interesting to consider as flux pinning additions because of their potential for very strong pinning strength. This research describes the study of different magnetic phase additions to superconducting thin films, including: BaFe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">19</sub> , La <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.67</sub> Ca <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.33</sub> MnO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> , Y <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sub> , and SrRuO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> . Nano-size additions with volume percent ranging from 0.5% to 5% were incorporated by utilizing pulsed laser deposition to form alternating layers of magnetic dopants and yttrium barium copper oxide to minimize degradation of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T_c</i> . Experimental critical current density ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">J_cm</i> ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H,T</i> )) results for mid temperature (30 K–65 K) / mid field (1 T–5 T) and low temperature (<30 K) / high field (>5 T) and microstructural TEM are presented. Results illustrate the benefits and interplay of combining magnetic flux pinning and core pinning by the magnetic additions and associated film defects, and suggest applications suitable for each system studied.

Low temperature and high magnetic field performance of a commercial piezo-actuator probed via laser interferometry.

The advances in the fields of scanning probe microscopy, scanning tunneling spectroscopy, point contact spectroscopy, and point contact Andreev reflection spectroscopy to study the properties of conventional and quantum materials under cryogenic conditions have prompted the development of nanopositioners and nanoscanners with enhanced spatial resolution. Piezoelectric-actuator stacks as nanopositioners with working strokes of 10μm and positioning resolution ∼(1-10) nm are desirable for both basic research and industrial applications. However, information on the performance of most commercial piezoelectric actuators in cryogenic environment and in the presence of magnetic fields in excess of 5T is generally not available. In particular, the magnitude, the rate, and the associated hysteresis of the piezo-displacement at cryogenic temperatures are the most relevant parameters that determine whether a particular piezoelectric actuator can be used as a nanopositioner. Here, the design and realization of an experimental setup based on interferometric techniques to characterize a commercial piezoelectric actuator over a temperature range of 2K ≤ T ≤ 260K and magnetic fields up to 6T are presented. The studied piezoelectric actuator has a maximum displacement of 30μm at room temperature for a maximum driving voltage of 75V, which reduces to 1.2μm with an absolute hysteresis of 9.1±3.3nm at T = 2K. The magnetic field is shown to have no substantial effect on the piezo-properties of the studied piezoelectric-actuator stack.

Planar laser-induced fluorescence thermometry in moderate-temperature flow using OH from photo-dissociation of water vapor

Since planar laser-induced fluorescence (PLIF) temperature measurements in a combustion-flow field can only be performed in regions in which OH is abundant (i.e., the reaction and high-temperature burnout zones), this paper investigates the feasibility of using photolysis of dissolved water to generate additional OH in the low-temperature and non-reaction zones of the flow field. Multi-line fluorescence showed that the generated OH had reached thermal equilibrium within 50 ns after dissociation with a fitting temperature of 300 K in room-temperature air. To further verify the technical accuracy, averaged PLIF images from dissociated OH were calibrated and compared with thermocouple measurements in a heated-flow field, and the average deviation in the 423–823 K temperature range was less than 40 K, with a relative system error better than 5%. The results of this paper confirm the feasibility and accuracy of the photo-fragment PLIF (PF-PLIF) temperature measurement in a low-temperature flow field. This makes it an effective complement to traditional PLIF measurements, with great significance for analysis and model validation of combustion processes in low temperature.

Similarity Calculation Method for Infield and Outfield Low-Temperature Environmental Tests of Aircraft Sealing Rubber Material

This study aims to accurately simulate the outfield low-temperature environment for the key components of aircraft in the parking state, using the infield low-temperature environmental test chamber, when there is a difference between the infield and outfield environments; and, moreover, reveal the similarity between the influences of the infield and outfield low-temperature environments on the elastic properties of the rubber sealing materials for aircraft. Two kinds of rubber materials were examined in the infield and outfield—the tensile springback test and the isobaric elongation test—and the measured data of low-temperature steady-state response (elastic property) were obtained under the typical temperature of −40 to 10 °C, finding that there is difference of elastic property between the infield and outfield environment. Three fitting methods were then used to describe the relationship between elasticity and temperature. In view of the difference of the elastic response of the typical rubber sealing materials to the low-temperature infield and outfield, a similarity calculation method of infield and outfield low-temperature tests was proposed, based on the translation and scaling transformation of the similarity curve. The outfield test data verify that the method proposed has high goodness of fit, and it is feasible and generalizable in the low-temperature performance testing and research of rubber materials and components.

Enhancement in the critical current density of BaTiO3-doped YBCO films by low-energy (60 keV) proton irradiation

Although YBa2Cu3O72212δ (YBCO) is one of the most promising superconducting materials for power applications, the fabrication of low-cost coated conductors with the high in-field performance remains challenging. Here, we report an efficient mixed-pinning landscape for enhancing the in-field performance of BaTiO3 (BTO)-doped YBCO films by low-energy (60 keV) proton irradiation. The smaller (2–4 nm), weaker but perhaps denser pinning sites have been successfully introduced by irradiation, which can form a mixed-pinning landscape with pre-doped BTO precipitates (5–15 nm), leading to the increased vortex pinning. In this case, the critical current density (J c) of YBCO films increases significantly, especially at low temperature and high magnetic field, and it increases three times near 6 T at 20 K when the irradiation dose is 1 × 1015 proton cm−2. Additionally, the c-axis length (c-parameter) of YBCO increases with the increase of irradiation dose, which indicates the decreasing oxygen content due to the excessive irradiation, thereby the reduction in critical transition temperature (T c). Employing low irradiation energy is beneficial for protons to stop inside YBCO film and thereby induces higher density defects when applying low doses. This fabrication technique is a practicable post-production solution to improve the in-field performance of nanoparticle-doped YBCO films.

Electrocaloric refrigeration capacity in BNT-based ferroelectrics benefiting from low depolarization temperature and high breakdown electric field

High electrocaloric performance around room temperature is achieved in lead-free (Bi0.5Na0.5)TiO3-based ceramicsviaenhancing the breakthrough electric field and lower depolarization temperature.

Impacts on Initial Condition Modification from Hyperspectral Infrared Sounding Data Assimilation: Comparisons between Full-Spectrum and Channel-Selection Scheme Based on Two-Month Experiments Using CrIS and IASI Observation

This paper discusses the performance difference between full-spectrum and channel-selection assimilation scheme of hyperspectral infrared observation, e.g. CrIS and IASI, on improving the accuracy of initial condition in numerical weather prediction. To accomplish this, we develop a 3D-Variational data assimilation system whose observation operator is a principal-component based fast radiative transfer model, which equips the direct assimilation of full-channel radiance from hyperspectral infrared sounders with high computational efficiency. This project’s primary goal is to demonstrate that assimilation of infrared observation in a full-channel mode could improve the accuracy of initial condition compared to selected-channel assimilation. Results show that full-channel assimilation performs better than selected-channel assimilation in modifying low and middle troposphere (1000 - 700 hPa, 700 - 400 hPa) temperature and water vapor field, while marginal improvements from temperature and water vapor field could be found over upper troposphere (400 - 100 hPa). This research also proves the feasibility of an alternative path to data assimilation for the full usage of hyperspectral infrared sounding observation in numerical weather prediction.