Fire Power Research Articles

Methods, Progress and Challenges in Global Monitoring of Carbon Emissions from Biomass Combustion

Global biomass burning represents a significant source of carbon emissions, exerting a substantial influence on the global carbon cycle and climate change. As global carbon emissions become increasingly concerning, accurately quantifying the carbon emissions from biomass burning has emerged as a pivotal and challenging area of scientific research. This paper presents a comprehensive review of the primary monitoring techniques for carbon emissions from biomass burning, encompassing both bottom-up and top-down approaches. It examines the current status and limitations of these techniques in practice. The bottom-up method primarily employs terrestrial ecosystem models, emission inventory methods, and fire radiation power (FRP) techniques, which rely on the integration of fire activity data and emission factors to estimate carbon emissions. The top-down method employs atmospheric observation data and atmospheric chemical transport models to invert carbon emission fluxes. Both methods continue to face significant challenges, such as limited satellite resolution affecting data accuracy, uncertainties in emission factors in regions lacking ground validation, and difficulties in model optimization due to the complexity of atmospheric processes. In light of these considerations, this paper explores the prospective evolution of carbon emission monitoring technology for biomass burning, with a particular emphasis on the significance of high-precision estimation methodologies, technological advancements in satellite remote sensing, and the optimization of global emission inventories. This study aims to provide a forward-looking perspective on the evolution of carbon emission monitoring from biomass burning, offering a valuable reference point for related scientific research and policy formulation.

Impact of Fine Water Mist Curtains on Fire Safety in Historic Buildings: A Case Study of Foshan Historical and Cultural District, Guangdong Province, China

ABSTRACT To address inadequate fire separation distances in historical buildings leading to extensive fire spread, practical research employing Fire Dynamics Simulator (FDS) was conducted. The study involved simulating a historical and cultural block in Foshan City to analyze variations in heat flux density and temperatures within a 5-meter radius of windows under fire powers of 1.5 MW, 6 MW, and 10 MW, with window openings at 10%, 25%, and 50%, respectively. The aim was to preserve the original architectural integrity without modifying existing fire separations. Augmentation of fire protection through the implementation of a fine water mist water curtain between buildings was proposed, and its efficacy in smoke and heat insulation was evaluated. Results indicate that, at 1.5 MW fire power, adjacent structures remain relatively secure with current fire separations. However, at 6 MW and 10 MW, fire spread to neighboring buildings was significant regardless of window opening area. Implementation of the water curtain with a nozzle flow coefficient (K) of 80, typical for standard coverage area sprinkler nozzles, and a spacing of 0.8 m, proved effective in enhancing smoke and heat insulation while also offering cost efficiencies. Optimal results were achieved with an average droplet size of 200 µm and nozzle pressure set at 6.0 MPa, corresponding to a nozzle flow rate of 615 L/min. These findings provide valuable insights for drafting specifications for the adaptive reuse of historical buildings and deploying fine water mist water curtains in confined spaces.

Biomass burning CO emissions: exploring insights through TROPOMI-derived emissions and emission coefficients

Abstract. Emissions from biomass burning are a significant source of air pollution, which can adversely impact air quality and ecosystems thousands of kilometres downwind. These emissions can be estimated by a bottom-up approach that relies on fuel consumed and standardized emission factors. Emissions are also commonly derived with a top-down approach, using satellite-observed fire radiative power (FRP) as a proxy for fuel consumption. Biomass burning emissions can also be estimated directly from satellite trace gas observations, including carbon monoxide (CO). Here, we explore the potential of satellite-derived CO emission rates from biomass burning and provide new insights into the understanding of satellite-derived fire CO emissions globally, with respect to differences in regions and vegetation type. Specifically, we use the TROPOMI (Tropospheric Monitoring Instrument) high-spatial-resolution satellite datasets to derive burning CO emissions directly for individual fires between 2019 and 2021 globally. Using synthetic data (with known emissions), we show that the direct emission estimate methodology has a 34 % uncertainty for deriving CO emissions (and a total uncertainty of 44 % including wind and CO column uncertainty). From the TROPOMI-derived CO emissions, we derive biome-specific emission coefficients (emissions relative to FRP) by combining the direct emission estimates and the satellite-observed FRP from the Moderate Resolution Imaging Spectrometer (MODIS). These emission coefficients are used to establish annual top-down CO emission inventories from biomass burning, showing that Southern Hemisphere Africa has the highest CO biomass burning emissions (over 25 % of global total of 300–390 Mt(CO) yr−1 between 2003–2021), and almost 25 % of global CO biomass burning emissions are from broadleaved evergreen tree fires. A comprehensive comparison between direct estimates, top-down and bottom-up approaches, provides insight into the strengths and weaknesses of each method: FINN2.5 has higher CO emissions, by a factor between 2 and 5, than all other inventories assessed in this study. Trends over the past 2 decades are examined for different regions around the globe, showing that global CO biomass burning emissions have, on the whole, decreased (by 5.1 to 8.7 Mt(CO) yr−1), where some regions experience increased and others decreased emissions.

Selection of Military Armored Vehicle Using Fuzzy EDAS method

Military armored vehicles are specially designed and equipped for defense and security activities. During military operations, the right vehicle selection is of vital importance for the success of the operation. This problem examined 5 different alternative military armored vehicles for operational and logistic success using the criteria Engine Power, Dimensions, Fire Power Range, Gradeability, and Armor Thickness. In military decision problems, some alternatives probably need to be evaluated regarding more than one conflicting criterion. The decision among these alternatives will usually involve other strategic-level decisions. Multi-criteria decision-making (MCDM) refers to making decisions in such a situation. Are there any methods and techniques available to solve MCDM problems? The evaluation according to distance from average solution (EDAS) method is a multi-criteria decision-making method whose effectiveness has been tested in other problem areas in the literature. In this study, we use the EDAS method to address the problem of military armored vehicle selection in a fuzzy environment. While a Type-1 fuzzy set is used in the fuzzy EDAS method, trapezoidal fuzzy numbers are preferred for military expert evaluation. The results of this study show that the fuzzy EDAS method is effective.

Understanding fire combustion characteristics and available safe egress time in underground metro trains: A simulation approach

Due to insufficient oxygen supply in the tunnel, incomplete combustion of the underground metro train fire easily produces toxic gases and smoke dust, causing difficulty in breathing for passengers and rescue. The experimental study of the fire combustion characteristics of metro trains in the tunnel is of great significance for designing metro fire extinguishing and fire prevention systems and providing reliable guidance for emergency evacuation in fire scenarios. A train fire model is established to study the effects of various factors on fire combustion characteristics and calculate the available safe egress time (ASET). The smoke spread characteristics under different conditions such as fire source power, fire source location, carriage layout, and train location are simulated. The simulation results show that the fire source power, location, and seat arrangement have a significant impact on the smoke spread characteristics of carriage fires and ASET.

Assessing the Influence of Safety Culture to Employee Safety Performance Mediated by Safety Communication in Coal-Fired Power Plant

This study analyzes the effect of safety culture on employee safety performance at a Coal Fired Power Plant (CFPP) in Java, as well as the mediating role of safety communication and moderating role of service years. This study aims to investigate the direct and indirect effects between the variables of safety culture, safety communication and employee safety performance. In addition, the study also explored the moderating role of service year in the relationship between safety culture and employee safety performance. Data was obtained from distributing questionnaires to CFPP employees using a stratified sampling method. SmartPLS SEM. The findings reveal that safety culture does not have a significant direct effect on employee safety performance. However, safety communication significantly mediates the relations between safety culture and employee safety performance. The service year does not moderate the relationship between safety culture and employee safety performance This indicates that other factors such as continuous training, reward system, and work environment may be more influential in this context.

Early polar-orbiting satellite-based fire remote sensing during the 1960s

ABSTRACT Satellite-based sensors such as the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Visible Infrared Imaging Radiometer Suite (VIIRS) now routinely provide a detailed picture of global fire activity on a daily basis. These systems explicitly included biomass burning as a phenomenon of interest, and their design was heavily influenced by experience gained with the comparatively primitive Advanced Very High Resolution Radiometer (AVHRR) first deployed on the TIROS-N satellite in the late 1970s. The AVHRR is generally recognized as the earliest spaceborne sensor to provide a middle infrared (MWIR) channel sensitive to actively burning vegetation fires and other high-temperature, sub-pixel thermal anomalies, forming the basis of countless fire studies before higher quality MODIS data became available. Here, we consider in the context of active fire monitoring a sensor much older than the AVHRR, namely the High Resolution Infrared Radiometer (HRIR) on board NASA’s Nimbus-I, -II, and -III satellites, launched in 1964, 1966, and 1969, respectively. This early imaging sensor had a single MWIR channel primarily intended for night-time meteorological observations (a complementary daytime near-infrared channel was added for Nimbus-III) that could potentially serve as a source of pre-AVHRR active fire data. To this end, we inspected night-time HRIR imagery acquired over the western United States and found unambiguous evidence of multiple confirmed wildfires in 1966. In addition, we found strong evidence of actively burning fires in Africa, specifically the Democratic Republic of the Congo, western Zambia, and northern Namibia, and in northern Australia, commensurate with their fire seasons. Our findings indicate that it was actually the HRIR that acquired the earliest MWIR imagery that could be used for identifying biomass burning from space, well over a decade before the first AVHRR was deployed. We found in addition that the retrieval of fire radiative power (FRP) from higher dynamic-range HRIR observations was potentially possible pending refined calibration.

Experimental study on the effect of longitudinal ventilation on spill fire characteristics in sloped tunnels

A series of spill fire tests were carried out in a reduced-scale tunnel (6 m × 0.6 m × 0.45 m), considering different discharge rates (60–140 ml/min), ventilation rates (0∼1.26 m/s), and tunnel slopes (3 %, 5 %, 7 %). Some crucial characteristic parameters during the quasi-steady combustion stage of tunnel spill fires were analyzed, including the diffusion shape of the liquid fuel, mass burning rate per unit area, flame morphology and plume temperature, and the critical ventilation velocity. The results show that as the tunnel slope increases, the diffusion shape of the liquid fuel transitions from circular to an ellipse shape and then to rectangular or linear shape. Moreover, the mass burning rate per unit area decreases with increasing ventilation rates at low ventilation (V < 0.5 m/s), while it remains almost constant at high ventilation rates (V ≥ 0.5 m/s). This could be attributed to variations in flame tilt behavior under different ventilation conditions. Predictive models for the flame tilt angle and the vertical temperature distribution of tunnel spill fires under the effect of ventilation were further established and verified. Furthermore, the critical ventilation velocity of tunnel spill fires remains essentially unchanged as the discharge rate (or fire source power) increases. This phenomenon was explained by analyzing the resistance of the spill fire plume and the buoyancy generated by the smoke temperature. This work could serve as a critical reference for assessing disaster risks and executing emergency rescue operations during tunnel spill fires.

Study on the Fire Characteristics of Dual Fire Sources and the Difference in Power Temperature of Different Fire Sources in Tunnel

To investigate the combustion characteristics of multiple fire sources in the tunnel caused by ‘jumping’ discontinuous fire spread, we utilized scaled model experiments, numerical simulation software, and theoretical research. Our study focused on analyzing the influence of different fire source powers on the temperature characteristics of double fire sources in the tunnel. We examined the temperature characteristics, critical wind speed, and change rule under various wind speeds, fire source spacing, and fire source powers. Additionally, we explored the temperature characteristics, critical wind speed, and change rule of different fire source powers under varying wind speed conditions. The mathematical model for roof temperature decay and the temperature decay coefficients of dual source fires were established through the analysis of scale-down model experiments and numerical simulations. In comparison to single-source fires, the temperature variations in the tunnel of dual source fires exhibit a more intricate pattern, with higher average temperature and temperature peak values. These values are influenced by factors such as fire source spacing and power. Numerical simulation software was utilized to investigate the impact of fire source spacing at 10 m, 15 m, and 20 m, as well as the effect of varying fire source power on the temperature distribution within a tunnel under consistent fire source position and growth coefficient. The study revealed that, with consistent double fire source position and ventilation conditions in the tunnel, the upstream fire source exhibited greater power than the downstream fire source, resulting in the lowest average and peak temperatures in the tunnel. This observation could potentially enhance escape and rescue operations within the tunnel. Similarly, the lowest average and peak temperatures in the tunnel were also identified, offering potential benefits for optimizing escape and rescue strategies in tunnel scenarios.

Wildfire combustion emission inventory in Southwest China (2001–2020) based on MODIS fire radiative energy data

Wildfires, a persistent environmental menace, are a significant source of harmful gases and particulate emissions. This study leverages the fire radiative power (FRP) method to delineate a comprehensive wildfire emission inventory for Southwest China from 2001 to 2020. Daily fire radiative power data derived from 1 km MODIS Thermal Anomalies/Fire products (MOD14/MYD14) were used to calculate the FRE and combusted biomass. Available emission factors were assigned to three biomass burn types: forest, grass, and shrub fires. Over the span of two decades, we have compiled data and estimated the annual emissions of carbon dioxide (CO2), carbon monoxide (CO), methane (CH4), sulfur dioxide (SO2), ammonia (NH3), nitrogen oxides (NOx), total particulate matter (TPM), black carbon (BC), organic carbon (OC), and non-methane volatile organic compounds (NMVOCs) to be 9809.13, 566.82, 25.79, 5.37, 12.25, 16.67, 133.53, 4.16, 41.81, and 97.23 Gg per year (Gg yr−1), respectively. In terms of fire type, forest fires accounted for the largest portion of total CO2 emissions (59.23%), with grass fires and shrub fires coming in second and third, accounting for 20.41% and 20.36%, respectively. Geographically, Yunnan Province were identified as the major contributor in Southwest China, accounting for 69.67% of the total emissions. Temporally, the maximum emission occurred in 2010 (24263.33 Gg), and the minimum emission occurred in 2017 (2917.66 Gg). And the emissions were mainly concentrated in February (23.33%), March (25.52%), and April (22.61%), which accounted for nearly three-fourths of the total emissions. The results of this study are much higher than those obtained by the burned area method, almost three times as high. In contrast, the results of this study are close to the fire emission data from the GFED4s and GFASv1.2 and QFEDv2.5r1 databases.

The effect of co-combustion of cattle manure and sawdust on energy recovered

The co-hydrothermal carbonization of biomasses has shown many advantages on charcoal yield, carbonization degree, thermal-stability of hydrocar and energy recovered. The goal of this study is to investigate the effect of co-combustion of cattle manure and sawdust on energy recovered. The results show that ash content ranged between 10.38%–20.00%, indicating that the proportion of each variable influences energy recovered. The optimum is obtained at 51% cattle manure and 49% sawdust revealing 37% thermal efficiency and 3.9 kW fire power. These values are higher compared to cattle manure individually which gives values of 30% and 2.3 kW respectively for thermal efficiency and fire power. Thus, the mixture of biomasses enhances energy recovered both in combustion and hydrothermal carbonization. Volatile matter is lower in mixture predicting that the flue gas releases is lower during combustion. Fixed carbon is higher in mixture predicting that energy recovered increases during the combustion of mixture than cattle manure individually. Higher Carbon content was noticed in mixture than cattle manure indicating that the incorporation of sawdust enhances heating value. The incorporation of sawdust in cattle manure can also enhance energy recovered and is more suitable for domestic and industrial application.

Study on temperature field beneath tunnel ceiling induced by transverse symmetrical double fires

During a tunnel fire incident, a substantial volume of high-temperature smoke gathers and disperses beneath the tunnel ceiling, posing significant risks of casualties and structural harm. A comprehensive comprehension of the temperature distribution of smoke beneath the ceiling is pivotal for the fire-resistant design and formulation of rescue plans for tunnel structures. This paper initially employs the FTP theory to analyze the fire scene resulting from fire spread under vehicle congestion. Subsequently, A set of numerical simulations is performed, and a prediction model of the temperature field for transverse symmetrical double fires is established according to the simulation results. Finally, an air entrainment model for transverse symmetrical double fires is proposed. The air entrainment amount under different fire spacing is obtained by theoretical derivation. Combined with the relationship between air entrainment amount, flame height, and maximum temperature, the variation of temperature field under the ceiling with fire spacing is explained from the mechanism. The results show that: the maximum temperature beneath tunnel ceiling increases with the increase of the fire power, decreases and then increases with the increase of the fire spacing and the variation has symmetry; The temperature attenuation along transverse and longitudinal directions under the ceiling following the exponential attenuation model, and the temperature attenuation rate is positively correlated with the maximum temperature. The transverse temperature attenuation is smaller than that of the longitudinal temperature under the same conditions; There is an internal relationship between the air entrainment, flame height and temperature field of the transverse double fires. The variation law of the temperature field beneath the ceiling depends on the degree of air entrainment limitation. Based on mirror model, this paper indicates that when the fire spacing is within a certain range, the combustion of the double fires can be effectively represented as near-wall fire.

Identification of peat-fire-burnt areas among other wildfires using the peat fire index

Fires in peat soils are distinguished from other wildfires by their duration, the release of combustion pollutants dangerous to human health, carbon loss, and other environmental impacts. Peat fires can be detected by superimposing fire data extracted on the basis of the thermal anomalies of the MODIS Terra/Aqua Moderate Resolution Imaging spectroradiometer on previously developed peatland maps. It is necessary to take into account, not all forest fires in peatlands turn into underground (peat) fires. In the example of the extensive fires that occurred in Central European Russia in 2010, the potential of using fire activity indicators (fire radiative power (FRP), temperature, duration, etc., obtained according to MODIS data) to identify soil (peat) fires and separate them from surface fires was investigated. A special peat fire index (consisting of maximum values of FRP, average temperature, duration of burning, and area of ignition) was proposed and tested. A model of the peat fire index is a value that shows the degree of confidence that this fire is a peat fire. This index takes values from 0 to 1: 0 – surface fire, 1 – peat soil fire; values in the interval mean that a fire can affect both the surface and soil of the peatland. After analyzing the proportions of identified fires, we found out that the devised peat fire index is the most effective indicator compared with others. This indicator makes it possible to identify with high probability not only peat fires, but also to identify surface fires, and this reduces the area of uncertainty. Although the obtained results require verification at other sites, they provide convincing evidence that remote data can be used to detect peat fires.

Study on the Length of Smoke Backlayering of Double-Source Fire in Tunnels.

In order to predict the smoke backlayering length of double-source fire in tunnels, this paper deduced the dimensional expressions for smoke backlayering length by theoretical analysis and proposed a prediction formula for smoke backlayering length in single-source fire on the basis of the Fire Dynamics Simulator. Based on the results, the paper proposed a method for studying the smoke backlayering length of double-source fire in the tunnel. By introducing the fire power influence coefficient α and the distance influence coefficient β, the formula for predicting smoke backlayering length in single-source fire was revised to obtain a new formula for predicting the smoke backlayering length of double-source fire. By comparing the formula prediction value with the simulation value, it is found that the prediction formula is almost accurate. This study will be helpful for understanding the multisource tunnel fire and predicting the smoke backlayering length of double-source fire in tunnels, which can provide guidance for tunnel fire rescue.

Modelling the Smoke Flow Characteristics of a Comprehensive Pipe Gallery Fire with Rectangular Section

In this study, a numerical model of the cable cabin of a comprehensive pipe gallery was established to study the smoke flow diffusion behaviour of a comprehensive pipe gallery fire under a rectangular cross-section. The effects of fire source power (Q = 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 MW) and fire source location (D = 10, 20, 40, 50, 60, 80, 100 m) on the smoke flow characteristics—such as smoke layer height and thickness, longitudinal airflow velocity, and ceiling temperature distribution—were analysed, and the corresponding prediction model was fitted. The results show the following: (1) The height of the smoke layer decreases with increasing fire power, and the predictive model of the smoke layer thickness obtained from the fitting is proportional to the smoke mass flow rate and inversely proportional to the aspect ratio of the pipe gallery. (2) Longitudinal air velocity prediction models of D &lt; 50 m and D ≥ 50 m are fitted, and the average error between them and the numerical simulation values is 9.611%. (3) The temperature decay gradient of the smoke decreases gradually with increasing distance from the fire source, while there is a significant temperature difference between the two sides of the fire source. The average relative errors of the dimensionless temperature rise models fitted upstream and downstream of the fire source in the form of ΔTT0=AeBD−XH+C exponentials with respect to the numerical simulations were 11.688% and 7.296%, respectively. The results of the study can provide a reference for smoke flow and fire prevention and control in comprehensive pipe galleries.

Increasing frequency and intensity of the most extreme wildfires on Earth.

Climate change is exacerbating wildfire conditions, but evidence is lacking for global trends in extreme fire activity itself. Here we identify energetically extreme wildfire events by calculating daily clusters of summed fire radiative power using 21 years of satellite data, revealing that the frequency of extreme events (≥99.99th percentile) increased by 2.2-fold from 2003 to 2023, with the last 7 years including the 6 most extreme. Although the total area burned on Earth may be declining, our study highlights that fire behaviour is worsening in several regions-particularly the boreal and temperate conifer biomes-with substantial implications for carbon storage and human exposure to wildfire disasters.

Land Cover Disaggregated Fire Occurrence and Particulate Matter2.5 Relationship in the Mekong Region: A Comprehensive Study

Air pollution has become an increasing concern in the Mekong region due to seasonal vegetative burning triggered by related anthropogenic activities and climate change. While the assumption of a correlation between agriculture burning and air pollution is a common postulation, little evidence exists on the association between fire incidents and air pollution concentrations. The current study explores the relationship between satellite-derived fire occurrence, land surface characteristics, and particulate matter 2.5 (PM2.5) concentrations for the five Lower Mekong countries, namely Cambodia, Laos, Myanmar, Thailand, and Vietnam, in an effort to gain new insights into fire distributions related to air quality. Publicly available daily active fire hotspots from the VIIRS satellite instrument, annual land cover products from the MODIS satellite, and mean monthly ground-level PM2.5 estimates from the V5.GL.04 database were analyzed in two relational assessments; first, the distribution of VIIRS active fire counts and fire radiative power (FRP) temporally and spatially and secondly, the correlations between the monthly VIIRS active fire counts, cumulative monthly FRP and mean monthly PM2.5 estimates per country and land cover type. The results suggest a statistically significant positive correlation between monthly fire counts, cumulative FRP, and PM2.5 estimates for each country, which differ based on land cover. The strongest correlation between monthly fire incidences and PM2.5 estimates was found in the case of Myanmar. For all countries combined, fires detected in forests displayed the highest correlation with monthly PM2.5 estimates. This study demonstrates the use of the VIIRS active fire product and provides important insights into temporal and spatial fire distributions as baseline information for fire prevention and mitigation strategies in the Mekong region.

Diagnosing uncertainties in global biomass burning emission inventories and their impact on modeled air pollutants

Abstract. Large uncertainties persist within current biomass burning (BB) inventories, and the choice of these inventories can substantially impact model results when assessing the influence of BB aerosols on weather and climate. We evaluated discrepancies among BB emission inventories by comparing carbon monoxide (CO) and organic carbon (OC) emissions from seven major BB regions globally between 2013 and 2016. Mainstream bottom-up inventories, including the Fire INventory from NCAR 1.5 (FINN1.5) and Global Fire Emissions Database version 4s (GFED4s), along with the top-down inventories Quick Fire Emissions Dataset 2.5 (QFED2.5) and Visible Infrared Imaging Radiometer (VIIRS-)based Fire Emission Inventory version 0 (VFEI0), were selected for this study. Global CO emissions range from 252 to 336 Tg, with regional disparities reaching up to a 6-fold difference. Dry matter is the primary contributor to the regional variation in CO emissions (50 %–80 %), with emission factors accounting for the remaining 20 %–50 %. Uncertainties in dry matter often arise from biases in calculating bottom fuel consumption and burned area, influenced by vegetation classification methods and fire detection products. In the tropics, peatlands contribute more fuel loads and higher emission factors than grasslands. At high latitudes, increased cloud fraction amplifies the discrepancy in estimated burned area (or fire radiative power) by 20 %. The global OC emissions range from 14.9 to 42.9 Tg, exhibiting higher variability than CO emissions due to the corrected emission factors in QFED2.5, with regional disparities reaching a factor of 8.7. Additionally, we applied these BB emission inventories to the Community Atmosphere Model version 6 (CAM6) and assessed the model performance against observations. Our results suggest that the simulations based on the GFED4s agree best with the Measurements of Pollution in the Troposphere (MOPITT-)retrieved CO. While comparing the simulation with the Moderate Resolution Imaging Spectroradiometer (MODIS) and AErosol RObotic NETwork (AERONET) aerosol optical depth (AOD), our results reveal that there is no global optimal choice for BB inventories. In the high latitudes of the Northern Hemisphere, using GFED4s and QFED2.5 can better capture the AOD magnitude and diurnal variation. In equatorial Asia, GFED4s outperforms other models in representing day-to-day changes, particularly during intense burning. In Southeast Asia, we recommend using the OC emission magnitude from FINN1.5 combined with daily variability from QFED2.5. In the Southern Hemisphere, the latest VFEI0 has performed relatively well. This study has implications for reducing the uncertainties in emissions and improving BB emission inventories in further studies.

Multi-resolution monitoring of the 2023 maui wildfires, implications and needs for satellite-based wildfire disaster monitoring

The August 2023 wildfires over the island of Maui, Hawaii were one of the deadliest U.S. wildfire incidents on record with 100 deaths and an estimated U.S. $5.5 billion cost. This study documents the incidence, extent, and characteristics of the 2023 Maui wildfires using multi-resolution global satellite fire products, and in so doing demonstrates their utility and limitations for detailed fire monitoring, and highlights outstanding satellite fire observation needs for wildfire monitoring. The NASA 500 m Moderate Resolution Imaging Spectroradiometer (MODIS) burned area product is compared with PlanetScope 3 m burned areas that were mapped using a published deep learning algorithm. In addition, all the August 2023 active fire detections provided by MODIS on the Terra and Aqua satellites and by the Visible Infrared Imaging Radiometer Suite (VIIRS) on the S-NPP and NOAA-20 satellites are used to investigate the geographic and temporal occurrence of the fires and their incidence relative to the 3 m mapped burned areas. The geographic and diurnal variation on the fire radiative power (FRP), available with the active fire detections, is presented to examine how energetically the fires were burning. The analysis is undertaken for all of Maui and for the town of Lahaina that was the major population center that burned. Satellite active fires were first detected August 8th, 2023 in the early morning (1:45 onwards) on the western slopes of Mt. Haleakalā and were last detected August 10th in the early morning (at 2:46) over Lahaina and on the western slopes of Mt. Haleakalā. The FRP available with the VIIRS satellite active fire detections indicate that the fires burned less intensely from the beginning to the end of this three day period, the nighttime fires generally burned more intensely than the daytime fires, and the most intensely burning fires occurred over Lahaina likely due to the high fuel load in the buildings compared to the vegetation that burned elsewhere. The MODIS 500 m burned area product was too coarse to map most of the 18 burned areas that were mapped unambiguously at 3 m resolution with PlanetScope and covered 29.60 km2, equivalent to about 1.6% of Maui. This study highlights the limitations of systematically derived satellite fire products for assessment before, during and after wildfire disaster events such as those experienced over Maui. The needs for future fire monitoring of wildfire disaster events, and the recommendation for a fire monitoring satellite constellation, are discussed.

Application of Internet of Things and embedded technology in electronic communication

In order to explore the energy-saving control method of electronic communication, the author proposes the application of Internet of Things and embedded technology in electronic communication. The application makes full use of the “Internet of Things” and embedded technology to create an energy-saving system, send data to the energy-saving system to control the power supply, and control operation of electrical appliances to achieve energy saving results. According to the test resultsThe energy consumption of the system designed by the author after energy saving is 4.8335kWh, which is lower than that of the device before energy saving, which is 5.8424kWh and saves electricity. At different load current, the system output voltage is controlled at 220 V and the performance of the system is stable. ConclusionThe system designed according to the model proposed by the author has a good performance in terms of energy consumption and has a connection with Internet technology and embedded technology in fire communication power.