{"id":9239,"date":"2026-06-08T09:37:28","date_gmt":"2026-06-08T07:37:28","guid":{"rendered":"https:\/\/nersc.no\/?p=9239"},"modified":"2026-06-08T09:38:04","modified_gmt":"2026-06-08T07:38:04","slug":"satellites-reveal-hidden-hotspots-in-cold-cities","status":"publish","type":"post","link":"https:\/\/nersc.no\/en\/features\/satellites-reveal-hidden-hotspots-in-cold-cities\/","title":{"rendered":"Satellites reveal hidden hotspots in cold cities"},"content":{"rendered":"

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Satellites reveal hidden hotspots in cold cities<\/h1><\/div>[vc_column_text css=””]Arctic cities are shaped by long winters, snow, and frozen ground. Urban development in cold regions has therefore largely focused on shielding people from harsh climatic conditions through enclosed, well<\/strong>\u2011insulated environments. New research shows that large buildings can create localised heat hotspots during summer. This knowledge can provide urban planners with new tools to protect infrastructure built on permafrost and to develop more attractive outdoor spaces in northern cities.<\/strong><\/p>\n

Big footprints, warmer surfaces
\n<\/strong>Researchers from the Nansen Center, the University of Troms\u00f8, and the George Washington University (USA) published a study on summer surface temperatures in three very different northern cities: Fairbanks in Alaska, Troms\u00f8 in northern Norway, and Nadym in western Siberia.
\nDespite their contrasting layouts, all three show the same pattern, made visible by using satellite-based thermal measurements. Large, low-rise buildings consistently formed the warmest spots in the urban landscape. On their own, such buildings already absorb and store heat efficiently. But the strongest warming occurs where many of them are located close together. When large-footprint buildings are clustered into districts, their effects add up. Wide roofs, extensive paved areas, and limited vegetation create continuous surfaces that heat up together. In cold-climate cities, weak atmospheric mixing allows this heat to remain local rather than dispersing. The study shows that these clustered areas can reach surface temperatures up to 4\u202f\u00b0C warmer than their immediate surroundings.<\/p>\n

Rethinking urban heat in cold climates
\n<\/strong>Much of what we know about urban heat islands is based on research on temperate cities, where dense, tall building clusters often dictate summer hotspot patterns. The new findings challenge the direct transfer of this thinking to cold regions.
\nIn Arctic and sub-Arctic cities, limited atmospheric mixing and large expanses of impermeable surfaces mean that horizontal scale matters more than vertical density. In other words, a building\u2019s footprint can matter more than its height when it comes to temperature.<\/p>\n

Three cities, one clear signal
\n<\/strong>The study deliberately compared cities with very different forms. Fairbanks is spread out and transport is car-oriented. Troms\u00f8 is compact and coastal. Nadym is a dense, structured city built on permafrost. Across all three cities, isolated large buildings produced localised hotspots, but spatially continuous clusters of large buildings created the most persistent and intense summer heat patterns. This consistency across locations strengthens confidence that the pattern is robust and not tied to a single city or planning tradition.<\/p>\n

Why these findings matter for Arctic cities
\n<\/strong>Localised summer surface warming can increase stress on foundations and infrastructure, as permafrost is sensitive to temperature changes. This is particularly relevant where large buildings are clustered. Knowing where these local hotspots form gives engineers and planners a clearer basis for protecting vulnerable ground and prioritising maintenance.
\nAt the same time, summer warmth in the far north is not only a risk. During short summers, slightly warmer outdoor spaces can improve comfort and support everyday activity. In many Arctic cities, people already seek out sun\u2011exposed areas for social life, movement between buildings, and informal use of public space.
\nThis study highlights an important point: rather than focusing on resisting climatic conditions, cities can also make use of local microclimates to offset harsh environments. Warmer areas can actively be used to support outdoor activity and seasonal urban life. For urban planners and decision\u2011makers, this means moving beyond one\u2011size\u2011fits\u2011all solutions and instead designing cities that work better across seasons.<\/p>\n

Key researcher:<\/strong> Victoria Miles<\/span><\/a>[\/vc_column_text][\/vc_column][vc_column width=”1\/3″ css=”.vc_custom_1695033709348{padding-right: 0px !important;}”]

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Publication<\/strong><\/h3>\n

“Thermal amplification by large-footprint buildings in cold-climate cities: Implications for urban heat mitigation”<\/a>,<\/span> published in Building and Environment<\/em><\/p><\/div>

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Large low-rise buildings cause warming<\/strong><\/h3>\n

In this study, the warmest urban areas are linked to large, low\u2011rise buildings with very wide footprints. These include shopping centres, warehouses, airports, and large institutional complexes. In urban climate research, this building type is known as Local Climate Zone 8. Their design traps heat very efficiently.<\/p><\/div>

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Measuring urban heat from space<\/strong><\/h3>\n

The researchers measured urban heat using thermal satellite data from the Landsat programme. The analysis focuses on land surface temperature, not indoor conditions or human heat stress. By comparing similar neighbourhood types using the “Local Climate Zone” framework, the study identifies local heat “hotspots” that are up to 4\u202f\u00b0C warmer than their immediate surroundings.<\/p><\/div>[\/vc_column][\/vc_row]<\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"

[vc_row][vc_column][\/vc_column][\/vc_row][vc_row][vc_column width=”2\/3″ css=”.vc_custom_1693479579188{background-color: #ffffff !important;}”][vc_column_text css=””]Arctic cities are shaped by long winters, snow, and frozen ground. Urban development in cold regions has therefore largely focused on shielding people from harsh climatic conditions through enclosed, well\u2011insulated environments. New research shows that large buildings can create localised heat hotspots during summer. This knowledge can provide urban planners […]<\/p>\n","protected":false},"author":4,"featured_media":9241,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_relevanssi_hide_post":"","_relevanssi_hide_content":"","_relevanssi_pin_for_all":"","_relevanssi_pin_keywords":"","_relevanssi_unpin_keywords":"","_relevanssi_related_keywords":"","_relevanssi_related_include_ids":"","_relevanssi_related_exclude_ids":"","_relevanssi_related_no_append":"","_relevanssi_related_not_related":"","_relevanssi_related_posts":"","_relevanssi_noindex_reason":"","footnotes":""},"categories":[80],"tags":[],"class_list":["post-9239","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-features"],"acf":[],"publishpress_future_action":{"enabled":false,"date":"2026-06-15 22:41:57","action":"change-status","newStatus":"draft","terms":[],"taxonomy":"category","extraData":[]},"publishpress_future_workflow_manual_trigger":{"enabledWorkflows":[]},"_links":{"self":[{"href":"https:\/\/nersc.no\/en\/wp-json\/wp\/v2\/posts\/9239","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nersc.no\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/nersc.no\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/nersc.no\/en\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/nersc.no\/en\/wp-json\/wp\/v2\/comments?post=9239"}],"version-history":[{"count":3,"href":"https:\/\/nersc.no\/en\/wp-json\/wp\/v2\/posts\/9239\/revisions"}],"predecessor-version":[{"id":9253,"href":"https:\/\/nersc.no\/en\/wp-json\/wp\/v2\/posts\/9239\/revisions\/9253"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nersc.no\/en\/wp-json\/wp\/v2\/media\/9241"}],"wp:attachment":[{"href":"https:\/\/nersc.no\/en\/wp-json\/wp\/v2\/media?parent=9239"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nersc.no\/en\/wp-json\/wp\/v2\/categories?post=9239"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nersc.no\/en\/wp-json\/wp\/v2\/tags?post=9239"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}