Urban heat island causation and adaptation: Model development and application to Canadian cities

预计世界城市将因气候变化和城市发展而变暖，影响健康和可持续性成果。我的研究计划的长期目标包括确定城市热的地方设计相关的原因，并随之改善城市适应现有和未来的气候。城市发展从根本上改变了景观，产生城市热岛（UHI）。然而，用领先的城市气候学家的话来说，我们目前对城市热岛效应原因的理解仍然包括“更多的猜测而不是既定的事实”。文献中充满了对城市热岛强度的研究，但是，很少有研究令人满意地解决城市热岛的因果机制，主要是因为相关的模型没有充分代表关键的物理processes.I少数研究人员之一，世界各地发展先进的城市微气象模型。我和同事们开发了一个广泛使用的街道尺度温度模型，一个复杂的城市街道湍流热交换模型，以及第一个详细的行道树模型表示（通常用作热适应策略）。本研究的目标包括：（1）开发和评估一个全面的、评价良好的街道尺度城市气候模式;（2）完整评估不同季节和气候条件下城市热岛的成因机制; 3）对影响街道空气温度的几个未经检验的过程进行了新的评估：4）在两个城市和季节中，对植树对街道空气温度和建筑能耗的影响进行了耦合模型评估; 5）评估多伦多当前和未来气候的最佳热适应策略，并考虑其冷季影响。将与国际同事合作，在几个尺度上进行创新的数值模式开发和应用。我们的工作将捕捉任何其他城市建模平台无法解决的潜在重要气象过程。我们的树模型将被插入到国家的最先进的天气研究和预报（WRF）的气象模型，并在多伦多的街道树木和其他城市热适应策略的实施将通过全球气候模型预测的动态降尺度为当代和未来的气候进行评估。七名研究生和五名本科生将在一个刺激的环境中接受培训。调查结果将为加拿大城市对气候变暖的最佳适应提供信息。

The world's cities are projected to warm from climate change and urban development, impacting health and sustainability outcomes. The long-term objectives of my research program include identification of local design-related causes of urban heat and consequent amelioration of urban adaptation to existing and future climates.Urban development radically alters the landscape, generating urban heat islands (UHIs). Yet, in the words of leading urban climatologists, our current understanding of UHI causation still includes “more speculation than established fact.” The literature is replete with studies of UHI intensity; however, few studies satisfactorily address UHI causal mechanisms, principally because relevant models have not adequately represented key physical processes.I am one of few researchers worldwide developing advanced urban micrometeorological models. Colleagues and I developed a widely-used model of street-scale temperatures, a sophisticated model of turbulent heat exchange in city streets, and the first detailed model representation of street trees (often used as a heat adaptation strategy). Appropriately combined, these advances will generate numerical models capable of accurately resolving all UHI causation and adaptation mechanisms.The objectives of this proposal include: 1) development and evaluation of a comprehensive, well-evaluated street-scale urban climate model; 2) complete assessment of UHI causation mechanisms for diverse seasons and climates; 3) novel appraisal of several unexamined processes that affect street-level air temperature; 4) coupled model assessment of impacts of tree planting on street-level temperature and building energy consumption in two cities and seasons; 5) evaluation of optimal heat adaptation strategies for present and future climates in Toronto with consideration of their cold season impacts.Innovative numerical model development and application will be undertaken at several scales, in collaboration with colleagues internationally. Our work will capture potentially important meteorological processes not resolved by any other urban modeling platform. Our tree model will be inserted into the state-of-the-art Weather Research and Forecasting (WRF) meteorological model, and implementation of street trees and other urban heat adaptation strategies in Toronto will be assessed for contemporary and future climates via dynamical downscaling of global climate model projections. Seven graduate students and five undergraduate students will be trained in a stimulating environment. Findings will inform optimal adaptation of Canadian cities to a warming climate.