Gas Atmosphere Research Articles

Insight into high-temperature fast pyrolysis characterization, product distribution and interaction effect of municipal solid waste and its components under steam-containing hydrogen-rich syngas atmosphere

This research delves into the field of fast hydropyrolysis of mixed municipal solid waste (MSW), with the goal of understanding product distribution and interactions in a hydrogen-rich condition. Through experimental investigations on MSW and its components, this study thoroughly examines the impact of pyrolysis temperature and gasification atmosphere (30% H2+30% CO+20% CO2+20% H2O) on the yields and distribution of the three-phase products. As the temperature increases, the gas yield gradually increases, while the yields of tar and char gradually decrease. The introduction of a hydrogen source increases the methane content in the combustible gas, which generally reaches its maximum at 850 °C, and promotes aromatic formation in tar, making aromatics the main component of pyrolysis oil. Notably, aromatics have the highest-octane number in gasoline. This study highlights gasification as a promising technology for converting organic waste into valuable fuel, advancing waste management and energy recovery.

Numerical investigation on direct water injection characteristics under different injection and ambient conditions within oxygen/argon atmosphere

Improving efficiency and reducing emissions are essential to achieve carbon neutrality in transportation sector. The hydrogen-fueled argon power cycle (H2-APC) is a novel power system with high efficiency and zero emission by utilizing argon-oxygen mixture as working fluids. However, knock suppression is a problem within H2-APC engines. Direct water injection (DWI) is an effective method to inhibit detonation. Spray morphology greatly influences the effectiveness of DWI, the investigation of spray characteristics in oxygen/argon atmosphere is critical. This paper established a computational model based on experimental data to investigate DWI characteristics under different injection and ambient conditions within oxygen/argon atmosphere. The results reveal increased jet temperature leads to stronger superheated jet spray collapse, while Sauter mean diameter (SMD) decreases and atomization improves. Increasing jet pressure effectively reduces spray SMD and improves atomization effect and evaporation rate. Higher ambient temperature reduces ambient gas density, spray SMD and penetration are decreased and increased, respectively. Moreover, spray evaporation rate and evaporated mass are dropped with higher ambient pressure for both superheated and subcooled sprays. As ambient density rises, the capacity for jet perturbation and fragmentation is enhanced, and spray SMD decreases. The research results can provide an effective guide for the DWI strategy of H2-APC engines.

Evaluation of a Commercial MoS2 Dry Film Lubricant for Space Applications

Molybdenum disulfide coatings, particularly Microseal 200-1, have been extensively used as dry film lubricants for actuating mechanisms in space applications. Although Microseal 200-1 has historically been a popular choice for space missions, recent assessments indicate a need for reexamination. This study evaluates sliding friction in air and dry gaseous nitrogen atmospheres at ambient temperatures with both linear reciprocating and rotary unidirectional tribo-tests. Measurements are performed for Microseal 200-1 applied on substrates and surface treatments commonly used in aerospace components, particularly stainless steel and a titanium alloy. Our findings indicate that the friction of stainless steel balls sliding on Microseal 200-1-coated disks is significantly influenced by the environment as well as the disk substrate material. The average friction coefficient ranges from 0.12 to 0.48 in air and from 0.04 to 0.41 in dry gaseous nitrogen, and the amount of friction is consistently much higher for the Microseal 200-1 on the stainless steel than on the titanium alloy. Microscopy and surface analyses, including scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray fluorescence, of the coatings on stainless steel substrates reveals that the coatings are sparse and relatively thin, likely a key factor contributing to their high friction. This insight underscores the substrate dependence of this widely used coating and highlights the importance of detailed tribological testing in accurately assessing the tribological performance of commercial dry film lubricants, a key step towards improving the reliability and effectiveness of actuating mechanisms for space applications.

Formation conditions of the tungsten porous thin film with pulsed laser deposition under various gas atmosphere

Formation conditions of the tungsten porous thin film with pulsed laser deposition under various gas atmosphere

Transceiving telescope for a mobile TDLAS system for remote sounding of anthropogenic methane

In this paper, we report on stages of the development of a transceiving telescope for atmospheric gas analysis TDLAS systems. Design of transmitters and receivers for active remote sounding systems is an important problem when creating instruments for studying atmospheric parameters. Transmitter and receiver aperture size directly influences the minimum permissible and maximum practicable sounding ranges. The work describes the stages of designing the receiving and transmitting parts of an atmospheric gas analysis tunable diode laser absorption spectroscopy (TDLAS) system (with anthropogenic methane as a target gas). Calculations show that a backscattered signal is reliably detected over an optical path 0–1000 m long with the use of a transceiving telescope with aperture 50–80 mm diameter and magnification of no less than 5. This design enables minimizing the dead zone of the coaxial TDLAS system within the 1645–1655 nm spectral range, which is informative for anthropogenic methane sounding. The use of a transceiving telescope will ensure resistance to misalignment, namely, resistance to mismatch between the mutual overlap of the device field of view and the laser radiation spot on the topographic target. Results of this work can be useful when designing and manufacturing telescopes for TDLAS systems methane (CH4) and also other atmospheric gas analysis.

Thermodynamic properties of MnV2O6 and Mn2V2O7 at high temperatures

MnV2O6 and Mn2V2O7 are the key compounds during the manganese salt roasting for extracting vanadium from vanadium bearing slag. Thermodynamic properties of MnV2O6 and Mn2V2O7 are dispensable to get insight into the multi-phase reaction mechanism and clarify the phase evolution. In this study, the MnV2O6 and Mn2V2O7 compounds were synthesized through solid-state roasting routes under a nitrogen gas atmosphere, and their crystal structure and thermodynamic properties were determined using X-ray powder diffraction, differential scanning calorimetry, and drop calorimetry. The enthalpy increments of MnV2O6 and Mn2V2O7 were experimentally measured for temperatures ranging from 573 K to 1023 K and 573 K to 1173 K, respectively, using drop calorimetry for the first time. Based on the experimentally measured enthalpy increments, the temperature dependence of the molar heat capacity of MnV2O6 and Mn2V2O7 was then derived. Furthermore, thermodynamic properties such as enthalpy, entropy, and Gibbs free energy were also calculated. Finally, the Gibbs free energy of the chemical reactions during the roasting of vanadium slag was evaluated, and compared with other roasting techniques.

High-Temperature Reorganization Behavior of Single-Crystalline Porous 4H-SiC Thin Foils

This work reports on the high-temperature reorganization behavior of single-crystalline porous 4H-silicon carbide (4H-SiC) thin foils. Porous 4H-SiC thin foils are realized via state-of-the-art photoelectrochemical etching in hydrofluoric (HF) acid solution enabling for the first time a released foil with a diameter of 2 inches. Subsequent annealing under inert gas atmosphere and comparison between samples suggests that a temperature of 1500 °C allows for various degrees of compactification across the foil surface, whereas at 1600 °C single crystallinity can be preserved.

Study on bulge structure formation mechanisms of laser remelting in air atmosphere

As a key feature of a part or assembly, surface structure can effectively improve the surface properties of the workpiece. Laser remelting is a promising method for surface structure formation, but sensitive to ambient gases. Therefore, this paper presents a numerical model that incorporates the contribution of air atmosphere on surface bulge structure formation. For this, the model couples a concentration field to reflect the oxygen mass transfer in the melt pool and introduces a semi-empirical function to describe the contribution of oxygen to the surface tension. Based on the model, it discusses the surface structure formation mechanisms, the heat-mass transfer characteristics, the melt flow patterns, and the surface force transient evolutions. The results reveal that the action of air atmosphere on melt flow manifests itself through two mechanisms, namely, the enhancement of inward thermocapillary forces and the introduction of outward solutocapillary forces. Furthermore, combined with the laser remelting experiments on 304 stainless steels, the established model is validated concerning the surface bulge structure size, the melt pool depth, and the oxygen distribution.

Chemically catalytic upgrading of fermentation-derived biobutanol to long-chain biofuels

The upgrading of acetone-butanol-ethanol (ABE) mixture from biomass to long-chain biofuels has aroused increasing attention since it is beneficial for alleviating energy crises and promoting high-value utilization of biomass. The main key to the ABE conversion is to find catalysts that are widely available and inexpensive. In this study, a simple way to prepare a low-cost highly dispersed Cu/MgO catalyst for ABE alkylation was proposed, resulting in C5–C11 molecules. The effects of experimental parameters such as reduction method, copper loading, reaction time, reaction temperature, and gas atmosphere on the production of long-chain products were also investigated. Compared to using hydrogen gas for reduction, the use of sodium borohydride in methanol results in the highest long-chain product yields. A copper loading of 2.5% or 5% is optimal, while an excessive copper load causes its aggregation. Within 18 h, the longer the reaction time, the higher the total yield and the higher the proportion of long-chain products. When the temperature increases from 250 °C to 300 °C, the total yield increases while the proportion of by-products decreases. The nitrogen atmosphere is conducive to increasing total production as hydrogen can cause the loss of acetone via hydrogenation.

Influence of air temperature and interrelationship with greenhouse gases (CO2 and CH4) over Iraq using AIRS data

Global and regional observations of air temperature (AT) and specific atmospheric greenhouse gases (GHGs) such as methane (CH4) and carbon dioxide (CO2) are required for a variety of applications, including constraining global or regional estimates of their significant impacts on the climate system. The present study employs Atmospheric Infrared Sounder (AIRS) -Level3 monthly products for AT, CH4, and CO2, at two standard pressure levels (925 and 500 hPa) over Iraq during 2010–2016. Both CO2 and CH4 shows significant seasonal variation, with maximum (minimum) CO2 observed in June (October), while CH4 recorded three maximum peaks during April, August, and November, and a minimum in February. CH4 shows a negative correlation during winter (DJF), spring (MAM), summer (JJA), and autumn (SON) with correlation coefficients (R) −0.627, −0.734, −0.491, and −0.688, respectively. The P-value is below 0.05 (4.14 × 10−15, 2.13 × 10−22, 1.1 × 10−8, and 5.2 × 10−19) for the four seasons, indicating a negative linear relationship. CO2 shows a low negative correlation in DJF and SON, and a low positive correlation in MAM and JJA seasons, with R values equal to −0.315, −0.221, 0.059, and 0.079, for DJF, SON, MAM and JJA seasons, respectively. The P-value was greater than 0.05 (0.061, 0.728, 0.647, and 0.195) for the four seasons, respectively, indicating a nonlinear relationship with AT. The monthly averaged time-series for CH4 and CO2 shows an evident increase, with an annual average increase of 1.81% (4.75) ppbv/year and 3.31% (1.84) ppm/year, respectively. Analysis reveals that the major sink and sources for CH4 are the presence of hydroxyl (OH) radicals and vegetation, whereas the major sources for CO2 are anthropogenic emissions, burning fossil fuels, and land-use change. The satellite observations of AIRS can efficiently show the spatiotemporal variations of air temperature versus CH4 and CO2 for the study area.

Highly microporous activated carbons synthesized from sacrificial templating of melamine for CH4 and H2 storages and CH4/H2 adsorptive separation

Achieving carbon neutrality necessitates advancements in adsorbent-based gas storage technologies, particularly for maximizing the utilization of natural gas (CH4) and hydrogen (H2) as sustainable energy sources. Activated carbons, characterized by their high surface area, stability, and cost-effectiveness, emerge as promising candidates for CH4 and H2 storage applications. Here, we report highly microporous activated carbons prepared using sacrificial templating of melamine followed by Cs+ ion activation. The resulting activated carbon demonstrates exceptional microporous characteristics, boasting a significantly high micropore surface area (2311 m2/g) and micropore volume (1.070 cm3 g−1). These structural attributes translate into impressive CH4 (11.92 mmol/g at 298 K and 70 bar) and H2 (2.74 mmol/g at 298 K and 70 bar) storage capacities, underscoring its potential as a viable ambient temperature gas storage material. Furthermore, our evaluation extends to the performance of the activated carbon for adsorptive CH4/H2 separation. The activated carbon exhibits a notable CH4 working capacity (3.13 mmol/g at 298 K, 1–10 bar pressure swing) coupled with a moderate Ideal Adsorbed Solution Theory (IAST) selectivity (25). These findings highlight the suitability of the activated carbon for both CH4 and H2 storage applications, as well as the separation of H2 from CH4.

Improving Electrical Conductivity of LiFePO4 through Advanced Synthesis and Multidoping Techniques

Extensive research has been conducted to enhance the electrical conductivity of LiFePO4. Several techniques, including doping with metal cations, synthesizing nanocrystalline grains, and carbon coating, have been employed [1]. Recent advances in material synthesis have revolutionized LiFePO4, such as depositing conductive carbon coatings on active material particles and exploring surface doping techniques. These advanced approaches have significantly improved the mass transfer rate [2]. High-capacity LiFePO4 materials close to the theoretical specific capacitance have been obtained.Efforts are currently underway to improve the electronic and ionic conductivity of LiFePO4 to enhance its efficiency. However, before it can be widely used, the material's low electronic conductivity and suboptimal performance in high-speed regimes must be overcome. Doping with supervalent cations is an effective method for narrowing the energy gap and increasing the electrical conductivity of LiFePO4 [3]. Additionally, the synthesis of nanocrystalline grains and the deposition of conductive carbon coatings on the particle surface contribute to an increase in mass transfer rate, removing critical performance limitations of LiFePO4. Reducing the size of LiFePO4 to the nanoscale has been identified as a strategic method to shorten the diffusion length of Li-ions and accelerate electron-conducting pathways during charging and discharging cycles, ultimately improving the overall performance of the material.This work compares the doping process of LiFePO4 cathode material using two methods: solid-phase synthesis in a planetary ball mill and spray pyrolysis in an inert gas atmosphere. The studies on the synthesis and modification of LiFePO4 have significant potential to overcome existing limitations and unlock its full potential for integration into high energy density batteries. The above multidoping methods enable the production of doped LiFePO4 materials with specific capacitance approaching theoretical values. Acknowledgments This research was funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan (Grant No. AP19677233).

Effects of Lithium Metal Storage Environment on Its Reactivity Toward Polyethylene Oxide-Based Blend Electrolytes

Lithium metal has generated significant interest as an anode material because of its high theoretical capacity (3860 mAh/g). However, issues such as dendrite growth and lithium loss during cycling make this material incompatible with current liquid electrolytes. Solid polymer electrolytes (SPE) have been proposed as a potential replacement as they are non-flammable, able to resist dendrite growth, have decent ionic conductivity and good interfacial contact with lithium metal.One aspect that is often overlooked is the fact that passivation layers, initially reported by Naudin et Al (1), often form on the lithium metal surface and are hence intrinsic to the chemical composition of the lithium surface (2, 3). According to Otto et Al (4), residual quantities of atmospheric gases are often present in lithium metal storage environments, thus electrode surface modification is inevitable. This passivation layer is expected to impact the reactivity of the lithium metal anode (LMA) towards SPE. Moreover, such phenomenon was originally described by Peled et Al as the solid electrolyte interface (SEI) (5). Lithium metal reactivity towards PEO, suspected by Galluzo et Al (6), was recently reported by Liu et Al (7), under optimized conditions (ultra-thin neat materials), but the impact of this phenomenon in a realistic LMA environment has not been extensively investigated.In this study, the impact of gas exposure on a LMA was investigated by exposing freshly cut lithium rods to O2, CO2 and N2. The resultant passivation layers were characterized via XPS. The effect of passivation layer formation on LMA reactivity towards SPE was measured by exposing samples with pre-characterized passivation layers to common SPE materials. The resultant interface was characterized using Raman spectroscopy. SPE-passivation layer reactivity was correlated to ageing properties by EIS and kinetic charge transfer characteristics in galvanostatic linear polarization at the LMA-SPE interface, in a symmetric Li – SPE – Li stack.This study revealed that the chemical composition of the lithium metal passivation layer affects its reactivity towards SPE as well as the electrochemical performance of a Li-SPE-Li symmetric cell. A thorough characterization of the lithium metal passivation layer is essential for the understanding of some of the fundamental factors affecting all solid-state lithium metal battery performance and is therefore consubstantial with the development of modified LMA. C. Naudin et al., Characterization of the lithium surface by infrared and Raman spectroscopies. Journal of Power Sources 124, 518-525 (2003).S.-K. Otto et al., In-Depth Characterization of Lithium-Metal Surfaces with XPS and ToF-SIMS: Toward Better Understanding of the Passivation Layer. Chemistry of Materials 33, 859-867 (2021).P. R. G. Zhuang, F. Kong, F. McLarnon The reaction of clean Li surfaces with small molecules in ultrahigh vacuum: II. Journal of The Electrochemical Society, 159-164 (1998).S.-K. Otto et al., Storage of Lithium Metal: The Role of the Native Passivation Layer for the Anode Interface Resistance in Solid State Batteries. ACS Applied Energy Materials 4, 12798-12807 (2021).E. Peled, Film forming reaction at the lithium/electrolyte interface. Journal of Power Sources 9, 253-266 (1983).M. D. Galluzzo et al., Dissolution of Lithium Metal in Poly(ethylene oxide). ACS Energy Letters 4, 903-907 (2019).P. Liu et al., Increasing Ionic Conductivity of Poly(ethylene oxide) by Reaction with Metallic Li. Advanced Energy and Sustainability Research 3, 2100142 (2022).

Chemiresistive effect of p-type delafossite CuScO2 microsheets to gaseous alcohols.

The chemiresistive effect of an oxide significantly influences its electrical properties, which depend greatly on the interactions between the ambient gas molecules and the solid surface, including the gas adsorption and charge transfer still challenging to be clarified. In this work, we investigate the chemiresistive effect of the p-type delafossite CuScO2 microsheets by comparing their responses to various gaseous alcohols, which increase with an approximately linear relationship with the length of straight carbon chains from methanol to n-hexanol. A new mechanism is proposed to elucidate such a dramatic trend of observed chemiresistive change based on the first-principles calculations and test results. The increasing carbon chain length modulates the adsorption configuration and provides supplementary routes for electron transfer, which is assumed to account for the observed chemiresistive effect. This work may provide a novel perspective for the investigation and development of more advanced functional oxides for electrical applications.

A Synopsis on CO2 Capture by Synthetic Hydrogen Bonding Receptors.

Carbon dioxide (CO2) is one of the most abundant greenhouse gases in Earth's atmosphere and responsible for global warming. Therefore, aerial CO2 capture and sequestration has become a major task for human community. Though several adsorbents for CO2 including activated carbon, zeolites, metal-organic frameworks (MOFs), and other surface-modified porous materials are well developed, the supramolecular approaches using synthetic hydrogen-bonding receptors are less explored. This review article highlights the synthetic development of various artificial receptors and their properties toward fixation of aerial CO2 as carbonate (CO32-), bicarbonate (HCO3-), or carbamate (-NHCOO-/>NCOO-) ions, induced by excess fluoride (F-) or hydroxide (OH-) ions as their tetrabutylammonium salts. The utilization of encapsulated carbonate/bicarbonate/carbamate complexes in anion exchange metathesis for separation of oxyanions from aqueous solutions are also discussed. In addition, the release of CO2 and regeneration of receptor molecules are described in a number of occasions. Most importantly, the formation of anion complexes as crystalline materials in solid-state is described in terms of supramolecular chemistry and correlated with their solution-state properties. Finally, the types of receptors containing various functional groups are scrutinized in CO2 uptake, storage, and release processes and hints of endeavours for future research are delineated.

Modeling and Experimental Validation of Pre-Chamber Jet Penetration Considering Jet Density and Ejection Pressure Variations

Abstract Although pre-chamber (PC) is regarded as a promising solution to enhance ignition in lean-burn gas engines, a lack of comprehensive understanding of PC jet penetration dynamics remains. This study proposed a zero-dimensional (0-D) model for PC jet penetration, considering the mixing of combustion products and unburned gases and floating ejection pressure. A combustion completion degree was defined employing fuel property and heat release to estimate varying jet density. Pressure differences between PC and the main chamber (MC) were referred to as the ejection pressure. Then, this model was validated against experiments from a constant volume chamber and a rapid compression and expansion machine with CH4-H2 blends at different equivalent ratios. Results showed that the proposed model can provide a good prediction in stationary and turbulent fields with the calibrated model coefficient. The overall jet penetration exhibits a t0.5 dependence due to its single-phase characteristic and the relative lower density compared to ambient gas in MC. The flame propagation speed and heat release in PC influence the combustion completion degree at the start of jet ejection, the mass fraction of burned gas in jet increases with the equivalent ratio. Jet penetration is primarily driven by ejection pressure, with tip dynamics barely affected by the pressure difference after the peak. Tip penetration intensity increases with increased fuel equivalent ratio and H2 addition, owing to the faster flame propagation. These findings can offer useful suggestions for model-based design and combustion model development for gas engines.

A Review on Design and Mechanical Properties of Additively Manufactured NiTi Implants for Orthopedic Applications.

NiTi alloy has a wide range of applications as a biomaterial due to its high ductility, low corrosion rate, and favorable biocompatibility. Although Young’s modulus of NiTi is relatively low, it still needs to be reduced; one of the promising ways is by introducing porous structure. Traditional manufacturing processes, such as casting, can hardly produce complex porous structures. Additive manufacturing (AM) is one of the most advanced manufacturing technologies that can solve impurity issues, and selective laser melting (SLM) is one of the well-known methods. This paper reviews the developments of AM-NiTi with a particular focus on SLM-NiTi utilization in biomedical applications. Correspondingly, this paper aims to describe the three key factors, including powder preparation, processing parameters, and gas atmosphere during the overall process of porous NiTi. The porous structure design is of vital importance, so the unit cell and pore parameters are discussed. The mechanical properties of SLM-NiTi, such as hardness, compressive strength, tensile strength, fatigue behavior, and damping properties and their relationship with design parameters are summarized. In the end, it points out the current challenges. Considering the increasing application of NiTi implants, this review paper may open new frontiers for advanced and modern designs.

Collaborative disposal of exhaust gas and waste wind turbine blades: Mechanical properties of recycled glass fibres and economic analysis

The accumulation of waste wind turbine blades poses significant environmental challenges. Pyrolysis offers an industrially viable solution for both disposal and the recycling of valuable glass fibers from these blades. Exhaust gas from industrials with waste heat can be utilized to reduce the process cost. However, for mixed atmosphere of exhaust gas containing both CO2 and O2, its influence on resin matrix decomposition characteristics and fiber mechanical properties are currently unclear. This work provided a solution collaborated with exhaust gas to disposal of waste wind turbine blades, in which operating parameters (atmosphere composition and process procedure) were optimized. Results showed that the early invention at pyrolysis with low concentration of O2 in exhaust gas played a major role in facilitating the formation of surface protection. Atmosphere during oxidation of pyrolytic residual carbon was crucial in maintaining fiber strength. At this stage, the interaction between CO2 (especially at 15% concentration) and O2 could mitigating fiber degradation through promoting the re-oxidization of Si dangling bonds and reducing water corrosion. However, stepwise processing of pyrolysis first and then oxidation under exhaust gas with O2 containing was not recommended due to its little cost-effectiveness. The single step disposal of wind turbine blades collaborated with coal-fired flue gas could increase the strength of recycled glass fiber by over 50% and reduced process costs by 34%.

Determination of the sensing properties of the fluorescence-based sensor for atmospheric NO2 gas

Air pollution in urban areas poses a serious threat to human health and therefore the studies about the development of low cost and sensitive sensors to monitor the air quality with high spatial and low temporal resolution continue to be an extensive area in literature. In this study, oxime modified poly(4-(1-pyrenyl) styrene) (P(PySt)-NOX) probes were synthesized to use as a sensor to detect NO2 gas in ambient air. The structural characterization results showed that the probe was successfully synthesized. The sensitivity, selectivity, repeatability, and aging tests were performed during the study, and it was observed that P(PySt)-NOX loaded sensor is sensitive to NO2 for concentrations below 200ppb. The selectivity measurements were performed against O3 and SO2 which are common interfering gases in ambient air, and it was shown that the sensor is selective to NO2. Additionally, according to the aging tests performed in laboratory for 23 days, it was observed that the sensor is stable in this time interval. The studies showed the sensor synthesized and designed in this study is suitable for NO2 concentration measurements in ambient air where the concentration levels of NO2 is below 100 ppb.

State of polar climate in 2023

The year 2023 has become the warmest year on global record. As the Antarctic and Arctic are sensitive regions to global warming, the climate changes in 2023 in these regions have attracted widespread attention. In this study, using observations, reanalysis and remote sensing data, we reported detailed polar climate changes in 2023, including warming, sea ice, atmospheric composition and extreme events. Antarctic exhibited large east‒west regional differences and the coexistence of extreme warm and cold events. In Coats Land, Queen Maud Land and the Antarctic Peninsula, three and seven stations recorded the second and third highest autumn air temperatures in history, respectively. The Amundsen–Scott station experienced extreme warming event in July, with the temperature increasing by 40 °C in one day. Abnormal cooling was evident in the Ross Sea and neighboring regions which were predominantly winter (June–August) cold anomalies, with Marylin Station reaching the lowest winter temperature in history. The Arctic experienced the warmest summer after 1979, with an overall distribution of ‘warm land‒cold sea’ on annual average. Compared with the 1991–2020 average, the annual air temperature anomalies reached more than 2 °C in northern Canada and the Barents Sea–Kara Sea coast. Abnormal high summer temperature caused most severe wildfires in Canada on record and second largest daily cumulative melt area over the Greenland ice Sheet daily post-1979. Polar sea ice continued to decrease rapidly, with minimum sea ice extent in Antarctic and Arctic ranking the first and sixth lowest post-1979. For melt season, Arctic Ocean sea ice began to melt later in 2023 than the 2011–2023 average, and freeze onset was delayed due to high temperatures in summer and autumn. Additionally, the status of polar atmospheric greenhouse gases remains bleak, and major greenhouse gas concentrations continue to increase. The Antarctic ozone hole in 2023 formed approximately 10 d earlier and lasted longer than the 1979–2023 average, with a maximum daily area of 2.6 × 107 km2 on 21 September. This summary of polar climate changes in 2023 will help people better understand global climate change and draw attention to polar regions.