The 2018 Camp Fire: Meteorological Analysis Using In Situ Observations and Numerical Simulations
The 2018 Camp Fire: Meteorological Analysis Using In Situ Observations and Numerical Simulations
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DOI：
10.3390/atmos11010047
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发表时间：
2020-01-01
期刊：
影响因子：
2.9
通讯作者：
Clements, Craig B.
中科院分区：
文献类型：
--
作者：
Brewer, Matthew J.;Clements, Craig B.
2018年11月的营火迅速成为加州历史上最致命、最具破坏性的野火。在本案例研究中，我们调查了气象条件的贡献，特别是2018年Camp Fire期间发生的下坡风暴。点火前的干燥季节性条件导致该地区100小时燃料含水量达到创纪录的低水平。气象观测主要来自一些远程自动气象站和2018年11月8日部署到火灾的移动的扫描多普勒激光雷达。此外，在分析中综合了网格化业务预报模型和高分辨率气象模拟，为气象观测和下坡风暴结构提供背景。结果表明，这次暴雨与高空冷空气平流引起的中层反气旋Rossby波破裂有关。加州中部上空的一个反向低压槽产生了气压梯度，这可能增强了下坡风。观测到持续的地面风速在3-6米/秒之间，阵风超过25米/秒，而地面以上的风与间歇性的低空急流有关。事件的气象条件得到了很好的预测，考虑到当天的潜在火灾危险，火灾的严重程度并不令人惊讶。然而，单独使用地面网络并不能提供足够的观测来了解下坡风暴事件及其对火灾蔓延的影响。火灾管理操作可以受益于使用操作风廓线仪，以更好地了解下坡风暴和其他火灾天气现象的演变，这是很难理解和观察。
The November 2018 Camp Fire quickly became the deadliest and most destructive wildfire in California history. In this case study, we investigate the contribution of meteorological conditions and, in particular, a downslope windstorm that occurred during the 2018 Camp Fire. Dry seasonal conditions prior to ignition led to 100-h fuel moisture contents in the region to reach record low levels. Meteorological observations were primarily made from a number of remote automatic weather stations and a mobile scanning Doppler lidar deployed to the fire on 8 November 2018. Additionally, gridded operational forecast models and high-resolution meteorological simulations were synthesized in the analysis to provide context for the meteorological observations and structure of the downslope windstorm. Results show that this event was associated with mid-level anti-cyclonic Rossby wave breaking likely caused by cold air advection aloft. An inverted surface trough over central California created a pressure gradient which likely enhanced the downslope winds. Sustained surface winds between 3-6 m s(-1) were observed with gusts of over 25 m s(-1) while winds above the surface were associated with an intermittent low-level jet. The meteorological conditions of the event were well forecasted, and the severity of the fire was not surprising given the fire danger potential for that day. However, use of surface networks alone do not provide adequate observations for understanding downslope windstorm events and their impact on fire spread. Fire management operations may benefit from the use of operational wind profilers to better understand the evolution of downslope windstorms and other fire weather phenomena that are poorly understood and observed.