McMurdo Station Fog Climatology Matthew A. Lazzara Antarctic Meteorological Research Center Space Science and Engineering Center University of Wisconsin-Madison

Outline Data and “A Fog Day” Historical review Fun facts to know and tell… Interesting items found… Future work A Fog Day Definition: A Fog Day – There is at least one hour during the day that fog is reported (present weather or past weather) Data: Synoptic observations from NCDC (Navy) Climatology reports from ATS/SPAWAR A.Cayette

McMurdo Fog Climatology: What’s Normal? US Navy (NCDC) SPAWAR (Direct) Poor Data Quantity Why so little fog?

McMurdo Fog Climatology : Monthly View “Ice” Fog PeakLiquid Fog Peak ?

Fun facts to know and tell… More detailed analysis – looking at the largest fog category reported – WMO #40 Fog occurs at a wide range of temperatures, pressures, wind speeds, cloud coverage, etc. However: –Fog observations have a very high correlation with a preferred wind direction –Preferred Temperatures reflect fog type (liquid vs. ice) –Pressure – not too high or low –Clouds…..

Fog most in the wee hours to early morning to mid-morning 12-0 UTC

Majority of the fog events have an Easterly wind component!

East to East Southeasterly wind direction!!

Winds 0 to 4 MPH to 18 MPH to as high as 35 MPH!!

0 C/32F ~-23 C/~-10 F Ice Fog! Liquid Fog!

Fog occurs at neither very “High” nor “Low” Pressure

Fog occurs with either some or lots of sky coverage

Good News: Fog doesn’t always have clouds over it Bad News: It does enough, making it hard to track by satellite

Future work… Complete this initial review Case Studies 1999 to 2003 –Detailed/in-depth analysis of events –Satellite data – Terra and Aqua and more… Web site: – – Input from you! –Observers –Pilots –Forecasters –Researchers –Others

Questions ? Fog Web Site: Linda AWS site/M.Lazzara