Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA.
Advanced Strategic Planning and Policy Program, Command and General Staff College, Ft Leavenworth, KS, 66027, USA.
Int J Biometeorol. 2024 Dec;68(12):2663-2676. doi: 10.1007/s00484-024-02776-5. Epub 2024 Sep 17.
Increasing temperature will impact future outdoor worker safety but quantifying this impact to develop local adaptations is challenging. Wet bulb globe temperature (WBGT) is the preferred thermal index for regulating outdoor activities in occupational health, athletic, and military settings, but global circulation models (GCMs) have coarse spatiotemporal resolution and do not always provide outputs required to project the full diurnal range of WBGT. This article presents a novel method to project WBGT at local spatial and hourly temporal resolutions without many assumptions inherent in previous research. We calculate sub-daily future WBGT from GCM output and then estimate hourly WBGT based on a site-specific, historical diurnal cycles. We test this method against observations at U.S. Army installations and find results match closely. We then project hourly WBGT at these locations from January 1, 2025, to December 31, 2100, to quantify trends and estimate future periods exceeding outdoor activity modification thresholds. We find regional patterns affecting WBGT, suggesting accurately projecting WBGT demands a localized approach. Results show increased frequency of hours at high WBGT and, using U.S. military heat thresholds, we estimate impacts to future outdoor labor. By mid-century, some locations are projected to average 20 or more days each summer when outdoor labor will be significantly impacted. The method's fine spatiotemporal resolution enables detailed analysis of WBGT projections, making it useful applied at specific locations of interest.
温度升高将影响未来户外工作者的安全，但量化这种影响以制定当地适应措施具有挑战性。湿球黑球温度 (WBGT) 是职业健康、运动和军事领域调节户外活动的首选热指数，但全球环流模型 (GCM) 的时空分辨率较粗，并不总是能提供预测 WBGT 全天范围所需的输出。本文提出了一种在当地空间和每小时时间分辨率下预测 WBGT 的新方法，而无需采用先前研究中存在的许多假设。我们从 GCM 输出中计算亚日未来 WBGT，然后根据特定地点的历史日循环来估算每小时 WBGT。我们在美国陆军设施的观测结果对该方法进行了测试，发现结果非常吻合。然后，我们从 2025 年 1 月 1 日至 2100 年 12 月 31 日，在这些地点预测每小时 WBGT，以量化趋势并估计未来超过户外活动修改阈值的时期。我们发现影响 WBGT 的区域模式，这表明准确预测 WBGT 需要采用本地化方法。结果表明，WBGT 高值的小时数增加，并且根据美国军事热阈值，我们估计未来户外劳动的影响。到本世纪中叶，一些地区预计每年夏季将有 20 天或更多天数，户外劳动将受到重大影响。该方法的精细时空分辨率使 WBGT 预测的详细分析成为可能，使其在特定感兴趣地点具有应用价值。
