scholarly journals Role of Local Air‐Sea Interaction in Fire Activity Over Equatorial Asia

2019 ◽  
Vol 46 (24) ◽  
pp. 14789-14797 ◽  
Author(s):  
Jin‐Soo Kim ◽  
Su‐Jong Jeong ◽  
Jong‐Seong Kug ◽  
Mathew Williams
Keyword(s):  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. Libonati ◽  
J. M. C. Pereira ◽  
C. C. Da Camara ◽  
L. F. Peres ◽  
D. Oom ◽  
...  

AbstractBiomass burning in the Brazilian Amazon is modulated by climate factors, such as droughts, and by human factors, such as deforestation, and land management activities. The increase in forest fires during drought years has led to the hypothesis that fire activity decoupled from deforestation during the twenty-first century. However, assessment of the hypothesis relied on an incorrect active fire dataset, which led to an underestimation of the decreasing trend in fire activity and to an inflated rank for year 2015 in terms of active fire counts. The recent correction of that database warrants a reassessment of the relationships between deforestation and fire. Contrasting with earlier findings, we show that the exacerbating effect of drought on fire season severity did not increase from 2003 to 2015 and that the record-breaking dry conditions of 2015 had the least impact on fire season of all twenty-first century severe droughts. Overall, our results for the same period used in the study that originated the fire-deforestation decoupling hypothesis (2003–2015) show that decoupling was clearly weaker than initially proposed. Extension of the study period up to 2019, and novel analysis of trends in fire types and fire intensity strengthened this conclusion. Therefore, the role of deforestation as a driver of fire activity in the region should not be underestimated and must be taken into account when implementing measures to protect the Amazon forest.


2021 ◽  
Author(s):  
Thomas Smith ◽  
Jessica McCarty ◽  
Merritt Turetsky ◽  
Mark Parrington

<p>MODIS has provided an 18-year continuous record of global fire activity. Here we present a geospatial analysis of MODIS hotspots in the high latitudes of the northern hemisphere from 2003 through to 2020. By combining the hotspot data with multiple land-cover datasets relating to vegetation cover, permafrost, and peat, we investigate boreal and tundra wildfire regimes, including an assessment of a significant northwards shift and increase in fire activity in 2019 and 2020. We focus on the distribution of hotspots on high latitude peatlands and permafrost and the associated difficulties in confirming residual smouldering compustion of peat soils using current remote sensing technology.</p>


Fire ◽  
2019 ◽  
Vol 2 (4) ◽  
pp. 55 ◽  
Author(s):  
Alexander J. Schaefer ◽  
Brian I. Magi

For this study, we characterized the dependence of fire counts (FCs) on soil moisture (SM) at global and sub-global scales using 15 years of remote sensing data. We argue that this mathematical relationship serves as an effective way to predict fire because it is a proxy for the semi-quantitative fire–productivity relationship that describes the tradeoff between fuel availability and climate as constraints on fire activity. We partitioned the globe into land-use and land-cover (LULC) categories of forest, grass, cropland, and pasture to investigate how the fire–soil moisture (fire–SM) behavior varies as a function of LULC. We also partitioned the globe into four broadly defined biomes (Boreal, Grassland-Savanna, Temperate, and Tropical) to study the dependence of fire–SM behavior on LULC across those biomes. The forest and grass LULC fire–SM curves are qualitatively similar to the fire–productivity relationship with a peak in fire activity at intermediate SM, a steep decline in fire activity at low SM (productivity constraint), and gradual decline as SM increases (climate constraint), but our analysis highlights how forests and grasses differ across biomes as well. Pasture and cropland LULC are a distinctly human use of the landscape, and fires detected on those LULC types include intentional fires. Cropland fire–SM curves are similar to those for grass LULC, but pasture fires are evident at higher SM values than other LULC. This suggests a departure from the expected climate constraint when burning is happening at non-optimal flammability conditions. Using over a decade of remote sensing data, our results show that quantifying fires relative to a single physical climate variable (soil moisture) is possible on both cultivated and uncultivated landscapes. Linking fire to observable soil moisture conditions for different land-cover types has important applications in fire management and fire modeling.


2020 ◽  
Vol 20 (2) ◽  
pp. 995-1020 ◽  
Author(s):  
Yufei Zou ◽  
Yuhang Wang ◽  
Yun Qian ◽  
Hanqin Tian ◽  
Jia Yang ◽  
...  

Abstract. Large wildfires exert strong disturbance on regional and global climate systems and ecosystems by perturbing radiative forcing as well as the carbon and water balance between the atmosphere and land surface, while short- and long-term variations in fire weather, terrestrial ecosystems, and human activity modulate fire intensity and reshape fire regimes. The complex climate–fire–ecosystem interactions were not fully integrated in previous climate model studies, and the resulting effects on the projections of future climate change are not well understood. Here we use the fully interactive REgion-Specific ecosystem feedback Fire model (RESFire) that was developed in the Community Earth System Model (CESM) to investigate these interactions and their impacts on climate systems and fire activity. We designed two sets of decadal simulations using CESM-RESFire for present-day (2001–2010) and future (2051–2060) scenarios, respectively, and conducted a series of sensitivity experiments to assess the effects of individual feedback pathways among climate, fire, and ecosystems. Our implementation of RESFire, which includes online land–atmosphere coupling of fire emissions and fire-induced land cover change (LCC), reproduces the observed aerosol optical depth (AOD) from space-based Moderate Resolution Imaging Spectroradiometer (MODIS) satellite products and ground-based AErosol RObotic NETwork (AERONET) data; it agrees well with carbon budget benchmarks from previous studies. We estimate the global averaged net radiative effect of both fire aerosols and fire-induced LCC at -0.59±0.52 W m−2, which is dominated by fire aerosol–cloud interactions (-0.82±0.19 W m−2), in the present-day scenario under climatological conditions of the 2000s. The fire-related net cooling effect increases by ∼170 % to -1.60±0.27 W m−2 in the 2050s under the conditions of the Representative Concentration Pathway 4.5 (RCP4.5) scenario. Such considerably enhanced radiative effect is attributed to the largely increased global burned area (+19 %) and fire carbon emissions (+100 %) from the 2000s to the 2050s driven by climate change. The net ecosystem exchange (NEE) of carbon between the land and atmosphere components in the simulations increases by 33 % accordingly, implying that biomass burning is an increasing carbon source at short-term timescales in the future. High-latitude regions with prevalent peatlands would be more vulnerable to increased fire threats due to climate change, and the increase in fire aerosols could counter the projected decrease in anthropogenic aerosols due to air pollution control policies in many regions. We also evaluate two distinct feedback mechanisms that are associated with fire aerosols and fire-induced LCC, respectively. On a global scale, the first mechanism imposes positive feedbacks to fire activity through enhanced droughts with suppressed precipitation by fire aerosol–cloud interactions, while the second one manifests as negative feedbacks due to reduced fuel loads by fire consumption and post-fire tree mortality and recovery processes. These two feedback pathways with opposite effects compete at regional to global scales and increase the complexity of climate–fire–ecosystem interactions and their climatic impacts.


Author(s):  
C. Fuilla ◽  
P. Ménage ◽  
M. Imbert ◽  
H. Julien ◽  
F. Baud
Keyword(s):  

2017 ◽  
Vol 8 (3) ◽  
pp. 749-771 ◽  
Author(s):  
Praveen Noojipady ◽  
Douglas C. Morton ◽  
Wilfrid Schroeder ◽  
Kimberly M. Carlson ◽  
Chengquan Huang ◽  
...  

Abstract. Indonesia and Malaysia have emerged as leading producers of palm oil in the past several decades, expanding production through the conversion of tropical forests to industrial plantations. Efforts to produce sustainable palm oil, including certification by the Roundtable on Sustainable Palm Oil (RSPO), include guidelines designed to reduce the environmental impact of palm oil production. Fire-driven deforestation is prohibited by law in both countries and a stipulation of RSPO certification, yet the degree of environmental compliance is unclear, especially during El Niño events when drought conditions increase fire risk. Here, we used time series of satellite data to estimate the spatial and temporal patterns of fire-driven deforestation on and around oil palm plantations. In Indonesia, fire-driven deforestation accounted for one-quarter of total forest losses on both certified and noncertified plantations. After the first plantations in Indonesia received RSPO certification in 2009, forest loss and fire-driven deforestation declined on certified plantations but did not stop altogether. Oil palm expansion in Malaysia rarely involved fire; only 5 % of forest loss on certified plantations had coincident active fire detections. Interannual variability in fire detections was strongly influenced by El Niño and the timing of certification. Fire activity during the 2002, 2004, and 2006 El Niño events was similar among oil palm plantations in Indonesia that would later become certified, noncertified plantations, and surrounding areas. However, total fire activity was 75 % and 66 % lower on certified plantations than noncertified plantations during the 2009 and 2015 El Niño events, respectively. The decline in fire activity on certified plantations, including during drought periods, highlights the potential for RSPO certification to safeguard carbon stocks in peatlands and remaining forests in accordance with legislation banning fires. However, aligning certification standards with satellite monitoring capabilities will be critical to realize sustainable palm oil production and meet industry commitments to zero deforestation.


1998 ◽  
Vol 46 (4) ◽  
pp. 387 ◽  
Author(s):  
Philip K. Groom ◽  
Byron B. Lamont

Within the Proteaceae, 353 species confined to 7 genera in the Grevilleoideae have woody fruits. The majority (> 70%) occur in fire-prone vegetation on nutrient-poor, summer-dry soils of south-western Australia. These species are characterised by large, winged seeds contained within serotinous follicles. Seed release is mediated by desiccation of the follicle walls resulting from fruit death, although wet–dry cycles are required in some genera. After release, germination must take place by the next wet season, as the seeds are not long-lived. Seeds are particularly high in protein (40–60%), P (1–2%) and Fe (10–60‰) compared with other Proteaceae. Seeds are favoured food for pre- and post-dispersal granivores (insects, birds, rodents) and young seedlings are favoured by herbivores (insects, marsupials), with the more serotinous fruits providing extra protection for their seeds. Successful establishment is facilitated by the protective and water retentive role of the testa during germination, and the remobilisation of N and P from the cotyledons to the seedling within 10 weeks of emergence. Drought stress reduces seedling establishment in otherwise favourable postfire microsites and prevents it (assisted by herbivores) in mature vegetation. Typically, < 10% of seeds released after fire become seedlings, and < 50% of these survive the first summer. Among fire-killed species, species that produce few seeds are more likely to have drought-resistant seedlings, often associated with larger seeds and/or needle-shaped leaves. Species that resprout after fire produce a few large viable seeds per plant, whereas fire-killed species produce many smaller seeds. Of all the Proteaceae, the ecology of woody-fruited species is best known, providing great scope for comparative biology studies.


2020 ◽  
Vol 8 (7) ◽  
pp. 520 ◽  
Author(s):  
Giada Kyaw Oo D’Amore ◽  
Alberto Marinò ◽  
Jan Kašpar

Finite element analysis (FEA) is employed to simulate the thermo-resistance of a marine fire-proof door in the fire-resistance test defined by the International Code for the Application of Fire Test Procedures (2010 FTP Code) and required by the International Maritime Organization (IMO) for marine applications. The appropriate type of simulation adopted (i.e., steady or unsteady) is discriminated on the basis of a comparison between the numerical results and the experimental data. This appropriate model is used to evaluate the critical parameters affecting fire-proof door performance. A remarkable role of the thermal bridge at the door edges in fire resistance is assessed, along with the parameters that allow its reduction. These findings provide insight into how to design a thinner and lighter fire door.


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