mcmurdo station fog climatology 1973-1998
DESCRIPTION
McMurdo Station Fog Climatology 1973-1998. 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. - PowerPoint PPT PresentationTRANSCRIPT
McMurdo Station Fog McMurdo Station Fog ClimatologyClimatology1973-19981973-1998
Matthew A. LazzaraAntarctic Meteorological Research Center
Space Science and Engineering CenterUniversity of Wisconsin-Madison
Outline• Data and “A Fog Day”
• Historical review
• Fun facts to know and tell…
• Interesting items found…
• Future work
Definition: A Fog DayA Fog Day – There is at least one hour during the daythat fog is reported (present weather or past weather)
Data: 1973-1998 Synoptic observations from NCDC (Navy) 1999-2003 Climatology reports from ATS/SPAWAR
A.Cayette
McMurdo Station, Antarctica Fog Climatology 1973-2003
0
2
4
6
8
10
12
14
16
18
Jan-73
Jan-74
Jan-75
Jan-76
Jan-77
Jan-78
Jan-79
Jan-80
Jan-81
Jan-82
Jan-83
Jan-84
Jan-85
Jan-86
Jan-87
Jan-88
Jan-89
Jan-90
Jan-91
Jan-92
Jan-93
Jan-94
Jan-95
Jan-96
Jan-97
Jan-98
Jan-99
Jan-00
Jan-01
Jan-02
Jan-03
Time
Fo
g D
ays
McMurdo Fog Climatology: What’s Normal?
US Navy(NCDC)
SPAWAR(Direct)
Poor Data Quantity
Why so little fog?
McMurdo Station Fog Climatology 1973-2003
112
48
87
42
27
23
40
76
93
63
33
61
0
20
40
60
80
100
120
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Months
To
tal #
of
Fo
g D
ays
McMurdo Fog Climatology 1973-2003: 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…..
McMurdo Fog Climatology 1973-1998: Time of Day View
0
20
40
60
80
100
0 3 6 9 12 15 18 21
Hour of the day (UTC)
To
tal
# o
f F
og
Day
s
Fog most in the wee hours to early morning to mid-morning 12-0 UTC
Wind Direction
0
100
200
300
400
Fog days 1973-1998 (WMO #40)
Win
d d
ire
cti
on
in
De
gre
es
Majority of the fog events have an Easterly wind component!
Wind Direction vs. Fog Days1973-1998
0
50
100
150
200
250
45 90 135 180 225 270 315 360
Wind Direction Categories
Fo
g D
ay O
ccu
ren
ce
East to East Southeasterly wind direction!!
Wind Speed vs. Fog Days1973-1998
020406080
100120140
0 200 400 600 800 1000 1200 1400 1600
Wind Speed (Units? mps x100?)
Fo
g D
ay O
ccu
ren
ce
Winds 0 to 4 MPH to 18 MPH to as high as 35 MPH!!
Temperature vs. Fog Days1973-1998
0
20
40
60
80
100
2350 2400 2450 2500 2550 2600 2650 2700 2750 2800
Temperature (deg. K x10) Categories
Fo
g D
ay O
ccu
ren
ce
0 C/32F~-23 C/~-10 F
Ice Fog! Liquid Fog!
Fog occurs at neither very “High” nor “Low” Pressure
Sea Level Pressure vs. Fog Days1973-1998
020406080
100120140
9700 9750 9800 9850 9900 9950 10000 10050 10100 10150
Pressure (mb x10) Categories
Fo
g D
ay O
ccu
ren
ce
Fog occurs with either some or lots of sky coverage
Total Sky Cover vs Fog Days1973-1998
0
20
40
60
80
100
120
0 1 2 3 4 5 6 7 8
Total Sky Cover (octals) Categories
Fo
g D
ay O
ccu
ren
ce
Visibilities vs Fog Days
020406080
100120140160
0 10000 20000 30000 40000 50000 60000 70000 80000
Visibility Categories
Fo
g D
ay O
ccu
ren
ce
Fraction of Low Cloud vs Fog Days
0
50
100
150
200
0 1 2 3 4 5 6 7 8
Fraction of Low Clouds (Octals) Categories
Fo
g D
ay O
ccu
ren
ce
Good News: Fog doesn’t always have clouds over itBad News: It does enough, making it hard to track by satellite
Clouds vs Fog Days1973-1998
0
200
400
600
800
1000
1200
0 1 2 3 4 5 6 7 8
Coverage (octals) Categories
Fo
g D
ay O
ccu
ren
ce
Low
Middle
High
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:– http://amrc.ssec.wisc.edu/fog– http://amrc.ssec.wisc.edu/realfog.html
• Input from you!– Observers– Pilots– Forecasters– Researchers– Others
Questions ?
E-mail:[email protected]
Fog Web Site:http://amrc.ssec.wisc.edu/fog
http://amrc.ssec.wisc.edu/realfog.html
Linda AWS site/M.Lazzara