Biochemical and physical characterization of multi‐year and first‐year ice in the Lincoln Sea (between Canada and the North Pole)
Biochemical and physical characterization of multi‐year and first‐year ice in the Lincoln Sea (between Canada and the North Pole)
Lange, B.A.1,2,3; C. Michel4, J. Beckers3, J.A. Casey3, C. Haas3,6, A. Mucci5 & A. Niemi4
1Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany; 2University of Hamburg, Hamburg, Germany;
3University of Alberta, Edmonton, AB, Canada; 4Fisheries and Oceans Canada, Winnipeg, Canada;
5McGill University, Montreal, Canada; 6York University, Toronto, Canada
Results:
• A total of 11 MYI cores demonstrated a mean total chl a content of 0.93 mg/m2 (sd = 0.64); mean total phaeopigment content of 0.47 mg/m2 (sd = 0.45); mean chl a concentration of 0.35 mg/m3 (sd = 0.22); and mean phaeopiment concentration of 0.17 mg/m3 (sd = 0.15; Figure 2)
• A total of 7 FYI cores demonstrated a mean total chl a content of 0.71 mg/m2 (sd = 0.85); mean total phaeopigment content of 0.26 mg/m2 (sd = 0.21); mean chl a concentration of 0.58 mg/m3 (sd = 0.77); and mean phaeopiment concentration of 0.19 mg/m3 (sd = 0.15; Figure 2).
• Higher chl a content in sea ice near coast (e.g. lower latitudes;
Figure 3).
• Higher concentrations and content of chl a near the bottom of the sea ice cores (Figure 4).
References:
1. National Snow and Ice Data Center, Boulder, Colorado.
2. Maslanik, J., et al. 2011. Geophys. Res. Lett., 38, L13502, doi:10.1029/2011GL047735;
3. Parsons, T.R., et al. 1989. Pergamon Press, Toronto.173p.
Acknowledgements: We would like to thank all of the helicopter and twin otter pilots for their support and excellent and safe flying. Polar Continental Shelf Project was instrumental in the success of this project with their logistical and financial support.
The personal and logistical staff at CFS Alert military base were also very important throughout the campaigns.
Introduction:
• Record minimum summer SIE observed in September 20121.
• Rapid decline of Arctic Summer sea ice extent with reductions of MYI and a Shift to an ice pack dominated by FYI2.
• The contributions of FYI vs. MYI algae for Arctic primary production are unknown. Therefore ecological implications of a shift to more FYI are uncertain.
A
Figure 1: Maps of the Arctic Region: A) showing the Lincoln Sea study site with sample site locations; B) an overview map and; C) zoomed region of coastal (landfast sea ice) sample sites near CFS Alert.
Figure 2: Total chl a content in FYI and MYI cores extracted from locations in Figure 1.
Arrows correspond to locations that are adjacent to each other (locations shown in Figure 1).
Figure 5: Vertical salinity, chl a & phaeopigment profiles for MYI core 5‐10 with corresponding thick section cross‐ polarized texture images.
Contact:
Benjamin.Lange@awi.de
A B
C
Study Site:
• Lincoln Sea region of the High Arctic Ocean (Figure 1). Campaigns based out of CFS Alert on Ellesmere Island, Nunavut. This region is home to the thickest ice in the Arctic and will be one of the last refuges for MYI in the near future.
Methods Ice cores
• Extracted with a 9 cm diameter Kovacs ice corer.
• Cores processed for chl a3, texture, salinity and temperature.
• Recorded core length, snow depth and freeboard.
Floe Scale (100‐1000 m) Snow and Ice Surveys
• Ice thickness surveys using drill holes and EM‐31 (5‐20 m spacing's)
• Snow depth probe surveys (1‐5 m spacing's)
0.000 0.002 0.004 0.006 0.008 0.010 0.012 0.014
3‐102‐114‐112‐123‐124‐126‐12 1‐102‐104‐105‐101‐113‐115‐116‐111‐125‐127‐12
[Chl a] (mg)
Site‐Year (#‐YY)
Total Chl a (mg) Total Phaeo (mg)
FYI MYI
0.000 0.002 0.004 0.006 0.008 0.010 0.012 0.014
82.0 82.5 83.0 83.5 84.0 84.5 85.0 85.5 86.0 86.5
Chla (mg)
Latitude
FYI Cores MYI Cores
0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Concentration (mg m‐3)
Depth Fraction (depth from surface / total length)
Chl a FYI (mg m‐3) Chl a MYI (mg m‐3)
Figure 3: Total Chl a content vs. latitude. Latitude is an indicator for distance from the coast.
Figure 4: Chl a concentrations for MYI and FYI cores vs. depth fraction (which is the depth divided by total length).
0 cm
14 cm
26 cm
40 cm
56 cm
70 cm
70 cm
86 cm
100 cm
112 cm
125 cm
136 cm
146 cm
146 cm
179 cm 164 cm
196 cm
225 cm 210 cm
225 cm
242 cm
258 cm
273 cm
286 cm
301 cm
Sea Ice Core Cross Polarized Imagery from site A5, 2010/05/12
-320 -300 -280 -260 -240 -220 -200 -180 -160 -140 -120 -100 -80 -60 -40 -20 0
6.0 5.0
4.0 3.0
2.0 1.0 0.0
Chl a (mg/m3) Phaeo (mg/m3) Salinity (ppt)
-300 -280 -260 -240 -220 -200 -180 -160 -140 -120 -100 -80 -60 -40 -20 0
Depth (cm)
-7.0 -6.0 -5.0 -4.0 -3.0 -2.0 Temperature (oC)
Sea Ice Core Biochemical Analysis, from Alert site A5, 2010/05/12
