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Ocean Observations from Below Petermann Gletscher, GreenlandAndreas Münchow University of Delaware USAKeith Nicholls British Antarctic Service UKCéline Heuzé University of Gothenburg SwedenAnna Wåhlin University of Gothenburg SwedenAlan Mix Oregon State University USALaurie Padman Earth & Space Research USA
C21A-‐0693
• Drains 4% of the Greenland ice sheet
• Large break-‐ups in 2010 and 2012
• Fjord mostly ice-‐free in August
• Warming Atlantic waters fill ocean below floating glacier
• Large temperature and salinity variations near ice-‐ocean boundary
• Swedish icebreaker Oden visits Petermann Fjord Aug.-‐2015
• Moorings below ice shelf extend Oden survey data in space + time
• Ice shelf moorings measure ocean properties below floating glacier hourly
Petermann Gletscher Petermann Fjord and Nares Strait Petermann Ocean Weather Stations
Data:http://ows.udel.edu
Web logs:
http://IcySeas.orghttp://PolarFever.com
http://PetermannsGlacialHistory.wordpress.com
CTD-‐ship
CTD-‐glacierUNAVCO GPS Radar (ice thickness)
+• 2 ocean CTD• Two stations• Iridium short-‐burst data
Weather + GPS+
• 5 ocean CTD• One station• Iridium dial-‐up
−65˚ −64˚ −63˚ −62˚ −61˚ −60˚80˚30'
80˚40'
80˚50'
81˚00'
81˚10'
81˚20'
81˚30'
81˚40'0 10 20
km
−1200
−1000
−800
−600
−400
−200
0meters
First 100 days of ongoing ocean, air, and glacier properties with last data from Nov.-‐29, 2015 8:00 am UTC:
• Glacier ice drifts ~ 1190 m/year• Bi-‐monthly air temperature maxima• Down-‐glacier winds dominate
Funded by NASA, NSF, andSwedish Polar Secretariat
−0.8
−0.6
−0.4
−0.2
0.0
0.2
0.4
Pot.
Tem
pera
ture
, C
34.2 34.3 34.4 34.5 34.6 34.7 34.8Salinity, psu
27.5
27.6
27.7
27.8
27.9
810-‐m warm450-‐m300-‐m melt
115-‐m95-‐m cold
Ocean surveys August 2015
1. Under floating ice-‐shelf
2. Across-‐fjord at glacier terminus
3. Along-‐fjord into Nares Strait
4. Across-‐fjord at entrance−600
−500
−400
−300
−200
−100
0
Dep
th (m
)
20 30 40 50 60 70
Distance (km)
34.0 34.2 34.4 34.6 34.8 35.0Salinity
32
34
34.434.5
34.6
34.7
34.74
34.76
34.7
8
20 30 40 50 60 70
Distance (km)
−1.6 −1.2 −0.8 −0.4 0.0 0.4Temperature
−1.6−1.2−1.2
−0.8
−0.4
00
0.1
0.2
0.24
0.28
0.32
3.
−600
−500
−400
−300
−200
−100
0
Dep
th (m
)
0 5 10 15
Distance (km)
34.0 34.2 34.4 34.6 34.8 35.0Salinity
32
34
34.434.534.6
34.734.7234.7434.76
34.78
0 5 10 15
Distance (km)
−1.6 −1.2 −0.8 −0.4 0.0 0.4Temperature
−0.8
−0.8
−0.4
000.1
0.20.20.240.28
0.32
4.
−600
−500
−400
−300
−200
−100
0
Dep
th (m
)
0 10
Distance (km)
34.0 34.2 34.4 34.6 34.8 35.0Salinity
3032
34
34.434.534.6
34.734.72
34.74
34.76
34.7634.78
0 10
Distance (km)
−1.6 −1.2 −0.8 −0.4 0.0 0.4Temperature
−1.2−1.2−0.8
−0.8
−0.4−0.4
−0.4
0
0
0.1
0.1
0.2
0.2
0.24
0.24
0.26
0.26
0.28
0.28
0.280.30.320.340.360.380.4
2.
• Mooring data: red/blue symbols• Survey data: green/azure lines• Ocean density: thin black line• Glacier-‐Ocean mixing: thick black line
• ~ 1.2 ∘C bi-‐monthly cold pulses• Strong ocean T-‐S correlation• Pulses coincide with neap tide
Sill Front
West
East
PetermannFjord
Glacier CTDOcean Moorings
Ocean CTDSections 2. & 4.
δh=25m for h ∊ [350, 500] m
Sill ~ 430 m
δh=500m for h ∊ [500, 1000] m
1.Ice-‐shelfIce-‐shelf
Base of ice shelf 365 m below sea level 3 km from grounding zone
References:
• Johnson et al., 2011: Ocean circulation and properties in Petermann Fjord, Greenland. J. Geophys. Res., 106, C01003, doi:10.1029/2010JC006519.
• Münchow, A. et al., 2014: Interannual changes of the floating ice shelf of Petermann Gletscher, North Greenland from 2000 to 2012, J. Glac., 60, 489-‐499.
• Münchow, A., 2015: Volume and freshwater flux observations in Nares Strait to the west of Greenland at daily time scales from 2003 to 2009, J. Phys. Oceanogr., in press.
• Tinto, K. et al., 2015: Bathymetry in Petermann fjord from Operation IceBridgeaerogravity. Earth Plan. Sci. Let., 442, 58-‐66.