Skip to page content
USDA Forest Service

Research & Development Treesearch

Treesearch Home
About Treesearch
Contact Us
Research & Development
Forest Products Lab
International Institute of Tropical Forestry
Pacific Northwest
Pacific Southwest
Rocky Mountain
Southern Research Station
Help - We Participate  Government Made Easy

Global Forest Information Service

US Forest Service
P.O. Box 96090
Washington, D.C.

(202) 205-8333

You are here: Home / Search / Publication Information
Bookmark and Share

Publication Information

View PDF (1.0 MB)

Title: On the formation and persistence of superfog in woodland smoke

Author: Achtemeier, G.L.;

Date: 2009

Source: Meteorological Applications, Vol. 16: 215-225

Publication Series: Scientific Journal (JRNL)

Description: Dense fogs, comparable to historical fogs in England, have been implicated in numerous roadway accidents in the southern United States. Many of the fogs have occurred in association with prescribed burning. Direct measurements of superfog (fog reducing visibility to less than 3 m) were taken during burning of forest litter on 22 March 2003. Visibility was measured at 0.1 m implying an extinction coefficient of 39 120 km-1. The number of condensation nuclei required for fog to produce the observed visibility was about 1% of the number of particles released in wood smoke as reported in the literature. A recursive non-gradient mixing model shows (1) maximum excess liquid water (LWC) released was approximately 7.0 g kg-1, 23 times the LWC in natural fog, (2) superfog can form at the site of combustion then continue to form as it drifts downwind, and (3) superfog can modify air mass stability near the ground and persist for hours until dispersed by changing wind conditions or by solar heating after sunrise. Published in 2008 by John Wiley & Sons Ltd.

Keywords: highway accidents, visibility, dense fog, smoke, prescribed fire

Publication Notes:

  • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
  • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.



Achtemeier, G.L. 2009. On the formation and persistence of superfog in woodland smoke. Meteorological Applications 16: 215-225.


 [ Get Acrobat ]  Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility

USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.