WHAT CAN WE LEARN FROM SUB-ANUALLY RESOLVED WEST ANTARCTIC ICE CORE SULFATE? Daniel A. Dixon, P. A....
-
Upload
reynard-lang -
Category
Documents
-
view
217 -
download
0
Transcript of WHAT CAN WE LEARN FROM SUB-ANUALLY RESOLVED WEST ANTARCTIC ICE CORE SULFATE? Daniel A. Dixon, P. A....
![Page 1: WHAT CAN WE LEARN FROM SUB-ANUALLY RESOLVED WEST ANTARCTIC ICE CORE SULFATE? Daniel A. Dixon, P. A. Mayewski, S. Kaspari, S. Sneed, M. Handley ACKNOWLEDGEMENTS:](https://reader036.fdocuments.in/reader036/viewer/2022062408/56649efe5503460f94c137d9/html5/thumbnails/1.jpg)
WHAT CAN WE LEARN FROM SUB-ANUALLY RESOLVED WEST ANTARCTIC ICE CORE SULFATE?
Daniel A. Dixon, P. A. Mayewski, S. Kaspari,
S. Sneed, M. Handley
ACKNOWLEDGEMENTS: Office of Polar Programs, National Science Foundation, 109th Air National Guard, Ice Core Drilling Services, Raytheon Polar Services.
![Page 2: WHAT CAN WE LEARN FROM SUB-ANUALLY RESOLVED WEST ANTARCTIC ICE CORE SULFATE? Daniel A. Dixon, P. A. Mayewski, S. Kaspari, S. Sneed, M. Handley ACKNOWLEDGEMENTS:](https://reader036.fdocuments.in/reader036/viewer/2022062408/56649efe5503460f94c137d9/html5/thumbnails/2.jpg)
OVERVIEW● Sixteen sub-annually dated ice cores from West
Antarctica are used to examine the spatial and temporal distribution of sulfate for the last 200 years.
● The ice cores are dated using seasonal signals and well-known volcanic events.
● The sulfate is separated into its sea salt (ss) and excess (xs)SO4 components and the mean values are plotted vs. site elevation, distance from open water, and accumulation rate.
● Mean annual concentrations of ssSO4 are plotted vs. time.
● A robust spline is applied to the mean annual xsSO4 record and the smoothed series is plotted vs. time.
● The robust spline residuals are filtered to identify global-scale volcanic signals.
● The volcanic signals are examined using raw xsSO4 data.
![Page 3: WHAT CAN WE LEARN FROM SUB-ANUALLY RESOLVED WEST ANTARCTIC ICE CORE SULFATE? Daniel A. Dixon, P. A. Mayewski, S. Kaspari, S. Sneed, M. Handley ACKNOWLEDGEMENTS:](https://reader036.fdocuments.in/reader036/viewer/2022062408/56649efe5503460f94c137d9/html5/thumbnails/3.jpg)
INTERNATIONAL ITASETRAVERSES FOR THE
PERIOD 1997-2003
U.S.ITASE TRAVERSES
![Page 4: WHAT CAN WE LEARN FROM SUB-ANUALLY RESOLVED WEST ANTARCTIC ICE CORE SULFATE? Daniel A. Dixon, P. A. Mayewski, S. Kaspari, S. Sneed, M. Handley ACKNOWLEDGEMENTS:](https://reader036.fdocuments.in/reader036/viewer/2022062408/56649efe5503460f94c137d9/html5/thumbnails/4.jpg)
ICE CORE LOCATIONS
Map created using the RAMP DEM (Liu and others, 2001).
![Page 5: WHAT CAN WE LEARN FROM SUB-ANUALLY RESOLVED WEST ANTARCTIC ICE CORE SULFATE? Daniel A. Dixon, P. A. Mayewski, S. Kaspari, S. Sneed, M. Handley ACKNOWLEDGEMENTS:](https://reader036.fdocuments.in/reader036/viewer/2022062408/56649efe5503460f94c137d9/html5/thumbnails/5.jpg)
DATING THE CORES USING ANNUAL SIGNALS IN THE MAJOR ION TIMESERIES
• Ice core 01-5• 94-99m depth
Ion concentrations in parts per billion.
![Page 6: WHAT CAN WE LEARN FROM SUB-ANUALLY RESOLVED WEST ANTARCTIC ICE CORE SULFATE? Daniel A. Dixon, P. A. Mayewski, S. Kaspari, S. Sneed, M. Handley ACKNOWLEDGEMENTS:](https://reader036.fdocuments.in/reader036/viewer/2022062408/56649efe5503460f94c137d9/html5/thumbnails/6.jpg)
THE 1815 TAMBORA VOLCANIC ERUPTION IN xsSO4 ION CONCENTRATION TIMESERIES
All concentrations in parts per billion.
![Page 7: WHAT CAN WE LEARN FROM SUB-ANUALLY RESOLVED WEST ANTARCTIC ICE CORE SULFATE? Daniel A. Dixon, P. A. Mayewski, S. Kaspari, S. Sneed, M. Handley ACKNOWLEDGEMENTS:](https://reader036.fdocuments.in/reader036/viewer/2022062408/56649efe5503460f94c137d9/html5/thumbnails/7.jpg)
SPATIAL VARIABILITY OF MEAN ssSO4and xsSO4 CONCENTRATIONS (1891-1991)
![Page 8: WHAT CAN WE LEARN FROM SUB-ANUALLY RESOLVED WEST ANTARCTIC ICE CORE SULFATE? Daniel A. Dixon, P. A. Mayewski, S. Kaspari, S. Sneed, M. Handley ACKNOWLEDGEMENTS:](https://reader036.fdocuments.in/reader036/viewer/2022062408/56649efe5503460f94c137d9/html5/thumbnails/8.jpg)
EOF OF ANNUAL ssSO4 CONCENTRATIONS
![Page 9: WHAT CAN WE LEARN FROM SUB-ANUALLY RESOLVED WEST ANTARCTIC ICE CORE SULFATE? Daniel A. Dixon, P. A. Mayewski, S. Kaspari, S. Sneed, M. Handley ACKNOWLEDGEMENTS:](https://reader036.fdocuments.in/reader036/viewer/2022062408/56649efe5503460f94c137d9/html5/thumbnails/9.jpg)
EOF OF ANNUAL xsSO4 CONCENTRATIONS
![Page 10: WHAT CAN WE LEARN FROM SUB-ANUALLY RESOLVED WEST ANTARCTIC ICE CORE SULFATE? Daniel A. Dixon, P. A. Mayewski, S. Kaspari, S. Sneed, M. Handley ACKNOWLEDGEMENTS:](https://reader036.fdocuments.in/reader036/viewer/2022062408/56649efe5503460f94c137d9/html5/thumbnails/10.jpg)
TEMPORAL VARIABILITY OF ANNUAL ssSO4 CONCENTRATIONS IN ppb (dark line = 5-yr. run. av.)
![Page 11: WHAT CAN WE LEARN FROM SUB-ANUALLY RESOLVED WEST ANTARCTIC ICE CORE SULFATE? Daniel A. Dixon, P. A. Mayewski, S. Kaspari, S. Sneed, M. Handley ACKNOWLEDGEMENTS:](https://reader036.fdocuments.in/reader036/viewer/2022062408/56649efe5503460f94c137d9/html5/thumbnails/11.jpg)
ROBUST SPLINE SMOOTHED ANNUAL xsSO4 CONCENTRATIONS (in ppb)
![Page 12: WHAT CAN WE LEARN FROM SUB-ANUALLY RESOLVED WEST ANTARCTIC ICE CORE SULFATE? Daniel A. Dixon, P. A. Mayewski, S. Kaspari, S. Sneed, M. Handley ACKNOWLEDGEMENTS:](https://reader036.fdocuments.in/reader036/viewer/2022062408/56649efe5503460f94c137d9/html5/thumbnails/12.jpg)
ICE CORE LOCATIONS
Map created using the RAMP DEM (Liu and others, 2001).
![Page 13: WHAT CAN WE LEARN FROM SUB-ANUALLY RESOLVED WEST ANTARCTIC ICE CORE SULFATE? Daniel A. Dixon, P. A. Mayewski, S. Kaspari, S. Sneed, M. Handley ACKNOWLEDGEMENTS:](https://reader036.fdocuments.in/reader036/viewer/2022062408/56649efe5503460f94c137d9/html5/thumbnails/13.jpg)
FILTERED POSITIVE RESIDUALS FROM ROBUST SPLINESMOOTHED ANNUAL xsSO4 CONCENTRATIONS (in ppb)
![Page 14: WHAT CAN WE LEARN FROM SUB-ANUALLY RESOLVED WEST ANTARCTIC ICE CORE SULFATE? Daniel A. Dixon, P. A. Mayewski, S. Kaspari, S. Sneed, M. Handley ACKNOWLEDGEMENTS:](https://reader036.fdocuments.in/reader036/viewer/2022062408/56649efe5503460f94c137d9/html5/thumbnails/14.jpg)
THE 1963 AGUNG ERUPTION AS SEEN IN RAW
xsSO4 CONCENTRATION DATA (in ppb)
NO CLEAR VOLCANICSIGNAL
![Page 15: WHAT CAN WE LEARN FROM SUB-ANUALLY RESOLVED WEST ANTARCTIC ICE CORE SULFATE? Daniel A. Dixon, P. A. Mayewski, S. Kaspari, S. Sneed, M. Handley ACKNOWLEDGEMENTS:](https://reader036.fdocuments.in/reader036/viewer/2022062408/56649efe5503460f94c137d9/html5/thumbnails/15.jpg)
THE 1991 PINATUBO ERUPTION AS SEEN IN RAW xsSO4 CONCENTRATION DATA (in ppb)
NO CLEAR VOLCANICSIGNAL
![Page 16: WHAT CAN WE LEARN FROM SUB-ANUALLY RESOLVED WEST ANTARCTIC ICE CORE SULFATE? Daniel A. Dixon, P. A. Mayewski, S. Kaspari, S. Sneed, M. Handley ACKNOWLEDGEMENTS:](https://reader036.fdocuments.in/reader036/viewer/2022062408/56649efe5503460f94c137d9/html5/thumbnails/16.jpg)
CONCLUSIONS● West Antarctic ice core data indicate that there are two
distinct transport sources for West Antarctic sulfate: lower troposphere for regions below 1000m and mid-upper troposphere/stratosphere for areas above 1000m.
● There is no compelling evidence for anthropogenic impact on the Antarctic sulfur budget.
● These data indicate that some kind of climate transition occurs over Central West Antarctica at around 1940.
● Global-scale volcanic eruptions appear as significant peaks in the robust spline residual xsSO4 records from sites located above 1000m elevation but do not appear in the residual records from sites located below 1000m.
![Page 17: WHAT CAN WE LEARN FROM SUB-ANUALLY RESOLVED WEST ANTARCTIC ICE CORE SULFATE? Daniel A. Dixon, P. A. Mayewski, S. Kaspari, S. Sneed, M. Handley ACKNOWLEDGEMENTS:](https://reader036.fdocuments.in/reader036/viewer/2022062408/56649efe5503460f94c137d9/html5/thumbnails/17.jpg)
QUESTIONS ?...