Ensemble projections of wildfire activity and carbonaceous aerosol concentrations over the western United States in the mid-21st century.
Ensemble projections of wildfire activity and carbonaceous aerosol concentrations over the western United States in the mid-21st century.
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DOI：
10.1016/j.atmosenv.2013.06.003
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发表时间：
2013-10-01
影响因子：
5
通讯作者：
Kaplan, Jed O.
中科院分区：
文献类型：
--
作者：
Yue, Xu;Mickley, Loretta J.;Logan, Jennifer A.;Kaplan, Jed O.
我们基于A1B情景下15个气候模型的结果，估计了21世纪中叶(2046-2065年)美国西部未来的野火活动。我们通过回归当年和往年的气象变量和火灾指数来建立火灾预测模型，并对观测到的区域燃烧面积进行预测。根据生态区的不同，回归可以解释1980-2004年间观测到的年燃烧面积变化的0.25-0.60。我们还用温度、降雨量和相对湿度对每日燃烧面积进行了参数化。这种方法解释了森林生态区观测到的烧毁面积的约0.5%的变化，但在内华达州和加利福尼亚州的半干旱地区没有显示出预测能力。通过将15个气候模型的气象场应用到我们的火灾预测模型中，我们量化了我们在本世纪中叶进行的野火预测的稳健性。我们用回归方法计算了燃烧面积增加了24%-124%，用参数化法计算了增加63%-169%。我们的预测在西南部沙漠最为可靠，那里的所有GCM都预测了重大的(p<；0.05)气象变化。对于森林生态区，更多的GCM预测未来在参数化下燃烧的面积显著增加，而不是回归，因为后一种方法对水文变量敏感，这些变量在气候预测中显示出较大的模型间变异性。该参数化预测，在本世纪中叶气候更温暖、更干燥的情况下，火季将延长23天。使用化学输送模型，我们发现，与现在相比，野火排放将使美国西部夏季地表有机碳气溶胶增加46%-70%，黑碳增加20%-27%。极端时段的污染最为严重：在落基山脉森林的32个联邦一级地区，OC增加~90%，BC增加~50%，能见度从130公里下降到100公里。
We estimate future wildfire activity over the western United States during the mid-21st century (2046–2065), based on results from 15 climate models following the A1B scenario. We develop fire prediction models by regressing meteorological variables from the current and previous years together with fire indexes onto observed regional area burned. The regressions explain 0.25–0.60 of the variance in observed annual area burned during 1980–2004, depending on the ecoregion. We also parameterize daily area burned with temperature, precipitation, and relative humidity. This approach explains ~0.5 of the variance in observed area burned over forest ecoregions but shows no predictive capability in the semi-arid regions of Nevada and California. By applying the meteorological fields from 15 climate models to our fire prediction models, we quantify the robustness of our wildfire projections at mid-century. We calculate increases of 24–124% in area burned using regressions and 63–169% with the parameterization. Our projections are most robust in the southwestern desert, where all GCMs predict significant (p<0.05) meteorological changes. For forested ecoregions, more GCMs predict significant increases in future area burned with the parameterization than with the regressions, because the latter approach is sensitive to hydrological variables that show large inter-model variability in the climate projections. The parameterization predicts that the fire season lengthens by 23 days in the warmer and drier climate at mid-century. Using a chemical transport model, we find that wildfire emissions will increase summertime surface organic carbon aerosol over the western United States by 46–70% and black carbon by 20–27% at midcentury, relative to the present day. The pollution is most enhanced during extreme episodes: above the 84th percentile of concentrations, OC increases by ~90% and BC by ~50%, while visibility decreases from 130 km to 100 km in 32 Federal Class 1 areas in Rocky Mountains Forest.
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影响因子：
5.2
作者：
Gillett, NP;Weaver, AJ;Flannigan, MD
通讯作者：
Flannigan, MD
影响因子：
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作者：
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影响因子：
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作者：
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通讯作者：
Pacala, Steve
影响因子：
4.4
作者：
Martin, M. Val;Honrath, R. E.;Barata, F.
通讯作者：
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