Feeds

City heat leak can disrupt high-altitude winds

‘Heat islands’ have warmed winters – in some places

Bridging the IT gap between rising business demands and ageing tools

Urban heat islands are a contentious phenomenon in the study of global climate change, but a new University of California-led study suggests that city heat can reach far enough into the upper atmosphere to alter high-altitude winds, impacting climate thousands of kilometres away from where energy is consumed.

The study, published in Nature Climate Change, sought to resolve a long-standing problem in climate modelling: the apparent disparity between observed warming over the last fifty years on the one hand, and the predictions made by computer climate models.

As noted by AFP, northern hemisphere winters have, somewhat awkwardly, been warmer than predicted by existing computer models.

The problem, according to the new study, is that those models focus on predicting the impact of anthropogenic greenhouse gases and aerosols, and to date have not included the vast amount of heat released by cities.

The authors explain that their calculations suggest that of the 16 Terawatts of global energy consumption in 2006, 6.7 TW was consumed in the 86 metropolitan areas they examined in the study.

By incorporating that heat release, the researchers found “the inclusion of energy use at 86 model grid points where it exceeds 0:4Wm -2 can lead to remote surface temperature changes by as much as 1K [El Reg - Kelvin] in mid- and high latitudes in winter and autumn over North America and Eurasia”.

An announcement at Florida State University quotes Cai as saying: “The world’s most populated metropolitan areas, which also have the highest rates of energy consumption, are along the east and west coasts of the North American and Eurasian continents, underneath the most prominent atmospheric circulation troughs and ridges.

“The concentrated and intensive release of waste energy in these areas causes a noticeable interruption to normal atmospheric circulation systems, leading to remote surface temperature changes far away from the regions where the waste heat is generated.”

The paper describes the impact on atmospheric jets as “a robust change in atmospheric circulation in response to the anthropogenic heating due to energy consumption. There is an equatorward shift of the winter mid-latitude jet, with increasing westerly wind at 20°N and decreasing westerly wind at 40°N.”

Interestingly, the study says the notion that urban heat islands could affect high-altitude atmospheric currents was first considered fifty years ago in two late-1960s studies. It was excluded from later models because early studies suggested the “heat island forcing” was indistinguishable from natural fluctuations.

Those studies, the authors note, only lasted a few months. The new results suggest that longer-scale modelling of the impact of urban heat release produces a quantifiable, if localised, impact. The global impact, however, remains trivial at 0.01°C.

The work, part-funded by the National Oceanic and Atmospheric Administration, was conducted by Florida State University’s Ming Cai, the University of California’s Guang Zhang, and Aixue Hu of the National Center for Atmospheric Research. ®

Mobile application security vulnerability report

More from The Register

next story
Malaysian Airlines flight MH17 claimed lives of HIV/AIDS cure scientists
Researchers, advocates, health workers among those on shot-down plane
Mwa-ha-ha-ha! Eccentric billionaire Musk gets his PRIVATE SPACEPORT
In the Lone Star State, perhaps appropriately enough
All those new '5G standards'? Here's the science they rely on
Radio professor tells us how wireless will get faster in the real world
The Sun took a day off last week and made NO sunspots
Someone needs to get that lazy star cooking again before things get cold around here
Boffins discuss AI space program at hush-hush IARPA confab
IBM, MIT, plenty of others invited to fill Uncle Sam's spy toolchest, but where's Google?
Microsoft's anti-bug breakthrough: Wire devs to BRAIN SCANNERS
Clippy: It looks your hands are shaking, are you sure you want to commit this code?
prev story

Whitepapers

Designing a Defense for Mobile Applications
Learn about the various considerations for defending mobile applications - from the application architecture itself to the myriad testing technologies.
How modern custom applications can spur business growth
Learn how to create, deploy and manage custom applications without consuming or expanding the need for scarce, expensive IT resources.
Reducing security risks from open source software
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.
Consolidation: the foundation for IT and business transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.