Study
Human FactorsRecentModerate effect

Heatwaves intensify sea breeze cooling but exacerbate urban heat island discomfort

During heatwaves, while sea breezes offer a stronger cooling effect, the urban heat island's nighttime temperature amplification leads to significantly increased thermal discomfort.

Urban Climate · 2023

01

Key Findings

  • 01Heatwaves intensify the cooling effect of sea breezes.
  • 02The daily-averaged urban heat island intensity did not show significant differences between heatwave and non-heatwave periods.
  • 03During heatwaves, nighttime urban temperatures are higher, particularly during extreme heat episodes.
  • 04While heatwaves increase thermal discomfort, they are not solely sufficient to cause severe heat stress on their own.
02

Application

Design takeaway

Designers must consider the amplified nighttime urban heat island effect during heatwaves when developing strategies for thermal comfort, focusing on materials and designs that reduce heat absorption and retention.

How to apply

When designing or retrofitting urban spaces in similar climates, prioritize solutions that reduce heat absorption during the day and facilitate heat dissipation at night, particularly in residential and public areas.

Project actions

  • 01When researching thermal comfort, consider how different times of day and extreme weather events affect user experience.
  • 02Investigate the interplay between natural phenomena (like sea breezes) and urban infrastructure.
03

Method & Evidence

AimHow do heatwaves influence the intensity of the urban heat island effect and the perceived thermal comfort in a Mediterranean coastal metropolitan area?
MethodComparative analysis of meteorological data
ProcedureMeteorological data from urban and rural stations in Rome were collected and analyzed for the summer of 2022, specifically comparing heatwave days with non-heatwave days. This data was also compared to data from 2020, a year with more typical temperatures, to assess the impact of extreme heat events on sea breeze, urban heat island intensity, and thermo-hygrometric comfort.
ContextUrban climate and human thermal comfort in a Mediterranean coastal city (Rome, Italy)

Variables

IV["Presence of heatwaves","Time of day (day vs. night)"]
DV["Sea breeze intensity","Urban heat island intensity (UHII)","Thermo-hygrometric comfort"]
CV["Location (urban vs. rural)","Season (summer)","Year (comparison between 2022 and 2020)"]
04

Strengths & Limitations

Strengths

  • +Utilizes real-world meteorological data from a specific urban context.
  • +Compares heatwave conditions with typical conditions and across different years.

Limitations

The study is specific to Rome's climate and urban structure; results might not be directly transferable to other cities without adaptation.

Reliability & validity

The study's reliability is supported by the use of ground-based remote sensing and in-situ meteorological measurements. Validity is enhanced by comparing heatwave days to non-heatwave days and by comparing data across different years.

Think critically

How might the design of urban green spaces or water features be optimized to mitigate the amplified nighttime urban heat island effect during heatwaves?

05

Design Principles

"Urban microclimates are dynamic and can be significantly altered by extreme weather events, requiring adaptive design strategies that consider both daytime and nighttime conditions."

Understanding how extreme weather events like heatwaves interact with urban microclimates is crucial for designing healthier and more comfortable urban environments. This insight informs strategies for mitigating heat stress in cities, impacting public health and urban planning.

06

What This Means for Your Design

Even when the sea breeze cools things down during a hot day, cities can get much hotter at night during heatwaves, making people feel uncomfortable.

How to use in your project

  • 1.Reference this study when discussing the impact of climate on user comfort and the effectiveness of design interventions in urban environments.
07

Add to My Project

08

Quick Cite

(2023). Effect of heatwaves on urban sea breeze, heat island intensity, and outdoor thermo-hygrometric comfort in Rome (Italy). Urban Climate. https://doi.org/10.1016/j.uclim.2023.101735 Retrieved from https://designdex.org/study/38fa4b69-6a2b-4959-9f3f-b440fb97f7b5/heatwaves-intensify-sea-breeze-cooling-but-exacerbate-urban-heat-island-discomfort

Paragraph starter

Research indicates that during heatwaves, urban areas experience amplified nighttime temperatures due to the urban heat island effect, leading to increased thermal discomfort even when daytime cooling from natural phenomena like sea breezes is enhanced. This highlights the need for design strategies that address both diurnal temperature variations and extreme weather impacts on user comfort.

09

Source

Urban Climate

Effect of heatwaves on urban sea breeze, heat island intensity, and outdoor thermo-hygrometric comfort in Rome (Italy)

journal · 2023

View source

Questions about this research

What does the research say about heatwaves intensify sea breeze cooling but exacerbate urban heat island discomfort?
Designers must consider the amplified nighttime urban heat island effect during heatwaves when developing strategies for thermal comfort, focusing on materials and designs that reduce heat absorption and retention. Evidence: Urban Climate (2023).
Why does "Heatwaves intensify sea breeze cooling but exacerbate urban heat island discomfort" matter for design?
Understanding how extreme weather events like heatwaves interact with urban microclimates is crucial for designing healthier and more comfortable urban environments. This insight informs strategies for mitigating heat stress in cities, impacting public health and urban planning.
How can designers apply this research?
Designers must consider the amplified nighttime urban heat island effect during heatwaves when developing strategies for thermal comfort, focusing on materials and designs that reduce heat absorption and retention.
What were the main findings?
Heatwaves intensify the cooling effect of sea breezes.. The daily-averaged urban heat island intensity did not show significant differences between heatwave and non-heatwave periods.. During heatwaves, nighttime urban temperatures are higher, particularly during extreme heat episodes.. While heatwaves increase thermal discomfort, they are not solely sufficient to cause severe heat stress on their own.
What research method was used?
Comparative analysis of meteorological data.
How strong is the evidence?
Evidence strength is rated Moderate effect, based on a 2023 journal from Urban Climate.
What should I do differently in my next project?
When designing or retrofitting urban spaces in similar climates, prioritize solutions that reduce heat absorption during the day and facilitate heat dissipation at night, particularly in residential and public areas.
What are the limitations?
The study focuses on a single Mediterranean coastal city, and findings may vary in different urban typologies and climates. The definition of 'heatwave' and 'comfort' can also be subjective.
Is there evidence that heat island affects design outcomes?
During heatwaves in Rome, sea breezes become more effective at cooling, but the city's nighttime temperatures rise significantly, leading to greater overall thermal discomfort for inhabitants, though not necessarily severe heat stress. Understanding how extreme weather events like heatwaves interact with urban microcli Source: Urban Climate (2023).
Where does this urban research apply?
Urban climate and human thermal comfort in a Mediterranean coastal city (Rome, Italy) It sits within human factors research on designdex.org.

Related research topics

heat island design research · evidence on heat island · does heat island improve design outcomes · urban studies for designers · heat island and urban findings · human factors research evidence