Editing Microclimate (section)

===Cold air pool===
Examples of the [[Cold-air pool|cold air pool]] (CAP) effect are Gstettneralm Sinkhole in Austria (lowest recorded temperature {{convert|-53|C|abbr=on}})<ref>{{cite web|url=http://www.wetter-freizeit.com/mikroklima.html|title=Mikroklima – Definition – Wissenswertes|website= wetter-freizeit.com}}</ref> and [[Peter Sinks]] in the US.
The main criterion on the wind speed <math>v</math> in order to create a warm air flow penetration into a CAP is the following:
:<math>
\mathrm{Fr} = \frac{v}{Nh} \geq \mathrm{Fr}_c,
</math>

where <math>\mathrm{Fr}</math> is the [[Froude number]], <math>N</math> — the [[Brunt–Väisälä frequency]], <math>h</math> — depth of the valley, and <math>\mathrm{Fr}_c</math> — Froude number at the threshold wind speed.<ref>J. Racovec et al. Turbulent dissipation of the cold-air pool in a basin: comparison of observed and simulated development. Meteorol. Atmos. Phys. 79, 195–213 (2002).</ref>