Transcript Tracking DMS in Antarctica

Tracking DMS in Antarctica
Burton Gray
December 1, 2004
Oxidizing Boundary Layer
• Mixed Layer Once Thought to be
Chemically Inert
• Large Levels of Nitric Oxide Present
• Leads to Formation of OH
• Reacts with Chemical Species in the Mixed
Layer and the Snowpack
• Can Bias Results from Glacio-Chemists
Importance of DMS
• Released by Phytoplankton from Southern
Ocean
• Chemical Indicator of Biomass Production
• Could Provide Valuable Information in
Studying Past Climate Changes
Measuring DMS
• 2000-2001 Study from Davis, et al
– Expected significant atmospheric transport of
DMS and sulfate from coast to pole (10kft alt)
– Found very little unreacted DMS at Pole
• Elevated NO Maintains Highly Oxidizing
Environment
– Order of magnitude greater than that found in
Summit, Greenland and Alert, Canada
Tracking DMS
• Use 2000 Data
• Code Developed by Tao Zeng
• Backtracking Through x-Day Increments
• Compare DMS versus Other Chemical
Species Levels at Each Point Along the
Way
My Results
• Available Data: 11/09/00  12/31/00
• Range I Chose:
– 11/25/00  12/10/00
– Five-Day backtracking
• Backtracking Based on Meteorological
Data Only
• No Chemical Species Breakdown
My Results
Five-Day Backtracking Analysis from 11/25 to 12/10
-74
12/04
12/05
11/27
-76
12/03
12/06
-78
12/01
12/02
12/08
Latitude (deg)
-80
12/10
11/28
12/07
-82
11/30
12/09
-84
11/26
11/29
11/25
-86
-88
Starting Point
-90
-180
-140
-100
-60
-20
20
Longitude (deg)
60
100
140
180
My Results
Ten-Day Backtracking Analysis from 11/25 to 12/10
11/26
-60
11/27
11/25
-65
11/28
Latitude (deg)
-70
12/02
12/09
12/06
-75
12/03
12/08
12/01
12/10
-80
12/07
12/05
11/29
11/30
-85
12/04
Starting Point
-90
-180
-140
-100
-60
-20
20
Longitude (deg)
60
100
140
180
Future Work
• Experiment More with Number of
Backtracking Days
• Perform Chemical Species Breakdown at
Each Location to Isolate DMS
• Will Hopefully Lead to Better
Understanding of DMS Trajectory and
Influence