li2025ARC

Bridging the gap between applied meteorology and climate science: a white roof example

Dan Li^1*

¹ Department of Earth and Environment and Department of Mechanical Engineering, Boston University, Boston, USA

* corresponding author: lidan@bu.edu

Abstract

White roof is a widely-studied urban heat mitigation strategy and frequently incorporated into climate adaptation plans by cities. Assessing the effects of white roofs on temperature has often been approached from the perspective of applied meteorology. Here, the white roof problem is reframed to a climate science problem by focusing on the roof surface temperature, incorporating concepts of climate forcing, sensitivity, and feedback, and utilizing a linearized surface energy balance (SEB) model. Different from the Albedo Cooling Effectiveness (ACE) index used for \textit{quantifying} white roof effects, a new index called Albedo Cooling Sensitivity ($\mathrm{ACSs}$, where the subscript s indicates surface) is proposed as a stepping stone towards \textit{understanding} white roof effects. The variability of $\mathrm{ACSs}$ simulated by the Weather Research and Forecasting (WRF) model is found to be strongly related to the variability of convective heat transfer efficiency. It is recommended that climate forcing, sensitivity, and feedback should be integrated into studying a wide range of urban adaptation strategies.

Journal reference

Li et al. (in submission). Bridging the gap between applied meteorology and climate science: a white roof example

Code reference

https://github.com/DanLi-BU/WRF/tree/WRFALBEDO (tag: ALBfinal)

Data reference

Input data

Output data

Contributing modeling software

| Model | Version | Repository Link | Tag | DOI | |-------|---------|-----------------|-----|-----| | WRF | 4.2.2 | https://github.com/DanLi-BU/WRF/tree/WRFALBEDO | ALBfinal |

Reproduce my experiment

Fill in detailed info here or link to other documentation to thoroughly walkthrough how to use the contents of this repository to reproduce your experiment. Below is an example.

1. Install the software components required to conduct the experiment from contributing modeling software
2. Download and install the supporting input data required to conduct the experiment. wrfinputd03 is for the control run, and wrfinputd03_alb60 is for the high-albedo run. Do NOT modify URBPARM.TBL when considering high albedo for roofs because modifying URBPARM.TBL will alter the roof albedo for all domains.
3. Use the following namelist.input in the scripts directory to re-create this experiment:

| Script Name | Description | How to Run | | --- | --- | --- | | namelist.input_July | namelist to run the WRF experiment for July | | | namelist.input_Feb | namelist to run the WRF experiment for Feb | |

1. change sfsfclayphysics and blpblphysics of all three domains to 2 for using MYJ
2. change sfsfclayphysics and blpblphysics of all three domains to 5 for using MYNN

Reproduce my figures

Use the scripts found in the figures directory to reproduce the figures used in this publication.