Long exposures + cold temps. The vapor seen is coming from power and production plants to the south.
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/14727154@N03">John Murphy</a>
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/kingair42/2145679954/">Cold Over El Segundo</a>