Sites: 04
Ponds and leads

Site 04
 
As part of the ice morphology studies a wall profile of the ice was made at the lead edge. This showed substantial undercutting at the waterline. The temperature and salinity of the top meter of the lead indicated a slight freshening in the top 10 cm.    


View of ice edge. Notice the undercutting at the waterline.
Schematic of lead edge  
       
  |<----53----->|    
      <- 4 cm thick overhang
         
  ICE     38 cm deep water
    |<--------78-------->|  
         
         
         

 
Mini CTD profile at lead edge
Depth (cm) Salinity (psu) Temperature (oC)
5 18.2 -1.1
10 20.8 -1.1
15 23.4 -1.2
20 24.8 -1.2
25 25.2 -1.2
30 25.6 -1.2
35 26.0 -1.3
40 26.6 -1.3
45 27.0 -1.3
50 27.3 -1.3
55 27.5 -1.4
60 27.9 -1.4
65 28.2 -1.4
70 28.8 -1.4
75 29.0 -1.4
80 29.2 -1.4
85 29.4 -1.5
90 29.4 -1.5
95 29.4 -1.5
100 29.5 -1.5
     

The morphology of two melt ponds were surveyed. The first was an elongated pond with horizontal dimensions of 3 m x 15 m. The pond had a 2 cm thick ice skim on top, a water depth of 28 cm, with 76 cm of underlying ice. The pond water had a temperature of -0.6 oC and a salinity of 17.4 psu.

The second pond was smaller, 3 m x 6 m in horizontal extent. This pond also had a 2 cm thick ice skim on top, with a water depth of 24 cm and 84 cm of underlying ice. There was a small amount of stratification in the pond water. The top portion had a temperature of -0.8 oC and a salinity of 16.5 psu, while the bottom portion had a temperature of -0.9 oC and a salinity of 18 psu.


Typical melt pond on this floe.