Climatological Heat Waves in Norway -  a base for Operational Warning System

Abstract

<p>With increasing temperatures in Norway, the possibility of heat waves are assumed to increase. The Norwegian Meteorological Institute (MET Norway) is testing ways to monitor heat waves  and possibly implement an operational warning system for heat waves in the future. For this work, it was necessary to assess the development of observed heat waves in Norway.</p><p>Heat waves were computed from daily minimum and maximum temperatures for the period 1961-2020, for three example stations and maps. For the stations, time series were assessed. For the maps, an observation-based dataset on a 1×1 km grid was used. The two different normal periods 1961-1990 and 1991-2020 were also compared.</p><p>The method to qualify a heat wave determines the number of heat waves in a given summer. There are different methods used internationally. MET Norway wants to find a method that works for Norway, and maybe in cooperation with surrounding countries. The last couple of years we have had the same criterias as used in Denmark; the mean value of maximum temperature of three consecutive days ≥ 28 degrees. In this study we have looked at different methods to qualify a heat wave in Norway, since the Danish method indicated heat waves too frequently, also during the spring. The method for heat waves is based on the maximum and minimum temperature combined. We have looked at different temperature limits and different number of days. For other weather warnings, a 2 years return period is used for a yellow warning. When testing different methods, we found that the mean value of maximum temperature for 5 days ≥ 28 degrees combined with the mean value of minimum temperature for 5 days ≥ 16 degrees were likely to occur seldom enough and also give some heat stress to people and nature.</p><p>Climate services has worked together with the forecasting group at MET Norway to propose a method to use for both forecasting and climatology. This summer (2022) the heat wave monitoring system will be tested operationally, and an evaluation is due in the autumn.</p>

Using web GIS to promote stakeholder understanding of scientific results in sustainable urban development: A case study in Bergen, Norway

“…These heat waves, while unusual for Bergen, pose health risks, especially for vulnerable populations. As climate change intensifies, the city's residents and infrastructure face challenges in adapting to these increasingly frequent and severe heat events (Liu et al, 2023; Tilley Tajet et al, 2022).…”

“…Using remote sensing data and high‐resolution urban models, areas prone to heatwaves and air pollution can be pinpointed, allowing targeted action (Lappalainen et al, 2022; Schaefer et al, 2021). In Bergen, this information can help prioritize mitigation measures such as green infrastructure development (Venter et al, 2020) and implementation of heat warning systems (Tilley Tajet et al, 2022; Toloo et al, 2013).…”

Assessing the impact of urban microclimate on building energy demand by coupling CFD and building performance simulation

“…On the other hand, the investigated summer conditions are more common in South Norway. As global temperatures are rising, also Scandinavia will experience periods of extensive heat more and more frequently in the future [143]. Unlike in countries with warmer climates, neither the people nor buildings are adequately prepared for such a development.…”