|Sector||Heat stress and human discomfort|
|Description||Heat waves are characterized as periods of sustained, extreme heat, although there is no universal definition of a heat wave. For this application, a heat wave is defined according to Meehl and Tebaldi (2004) based on daily maximum air temperature (Tmax) and two percentile thresholds (T1 and T2) from the distribution of daily Tmax during the reference scenario period.|
|End User||General public, health authorities, urban planners|
|heatwaveduration||Hot period duration||yearly||Maximum number of consecutive days when: i) Daily Tmax is above T1 for at least three days, ii) the average Tmax is above T1 over the entire period, and iii) the daily Tmax must be above T2 every day of the period (the total heat wave period may be longer than three days).||days||T1 = 97.5th percentile T2 = 81st percentile||
|Provenance||Theese indicators are based on output from the Harmonie meteorological modell.|
|Validation||The simulations made by HARMONIE-AROME in Urban SIS has been validated against observations in Urban SIS deliverable 5.1, where an overview is given in Table 4.|
|Calculation caveats||Spatial representation:
Other caveats: O3, O4
Could be compared to:
Could be used with:
Both duration and frequency of heat waves may increase in Europe (Perkins et al. 2011). The provided indicator can give planners a hint of changes to expect in their city. The selected method (Meehl and Tebaldi 2004) provides information about heat wave duration.
|Experience user||Many methods to define a heatwave (Souch and Grimmond 2004, Perkins 2015).|
Meehl GA, C Tebaldi 2004: More intense, more frequent, and longer lasting heat waves in the 21st century. Science 305.5686, 994-997.
Perkins SE, Alexander LV, Nairn JR 2012: Increasing frequency, intensity and duration of observed global heatwaves and warm spells. Geophysical research letters. 39:20
Perkins SE 2015: A review on the scientific understanding of heatwaves—their measurement, driving mechanisms, and changes at the global scale. Atmospheric Research, 164, 242-267.
Souch C, CSB Grimmond 2004: Applied Climatology: Heat Waves. Progress in Physical Geography, 28, 599-606. doi: 10.1191/0309133304pp428pr