Ice floes were accessed from the LMG throughout the cruise for snow and ice studies that entailed ice and snow thickness transects, snow collections, ice core collections and brine collections. In addition CTD deployments and measures of bacterial and algal production were undertaken while on these long term ice stations. Thickness transects and snow pits were accomplished in conjunction with OG-241.
\nAt the ice stations we measured ice thickness transects 20 m to 100 m in length. These transects were often located in an area under which the divers (BG-244) would be working. Along these transect lines we measured snow depth, slush depth (if present), depth ofthe wicked layer (the layer of snow above the slush layer which has absorbed moisture), ice thickness, freeboard (the distance from sea level to the ice surface), and ice surface temperature.
\nWhen time and ice conditions permitted, surveys of snow depth and ice thickness were conducted along 20 to 100-m-long lines. These survey lines were laid out on the ice and snow depth, freeboard, and ice thickness were measured every meter along the line. This was a team effort with individual people working a 1 m auger, a 2 m auger, snow pits, and an ice thickness tape. Ice cores were also taken to provide a detailed look at ice properties and structure. These surveys were conducted at 10 sites in 2001 and are summarized in the 2001 table. Surveys were conducted at 12 sites in 2002 and are summarized in the 2002 table.
\n| Summary of 2001 survey sites | \nSummary of 2002 survey sites | \n
| Robert | \nSite 1 | \n
| TR1 | \nSite 6 | \n
| TR2 | \nSite 9-1 | \n
| TR3 | \nSite 9-2 | \n
| TR4 | \nSite 21-1 | \n
| TR5 | \nSite 21-2 | \n
| TR10 | \nSite 24-1 | \n
| Billy | \nSite 24-2 | \n
| Fernando | \nSite 29 | \n
| Yoga | \nSite 30 | \n
| \u00a0 | \nSite 31-1 | \n
| \u00a0 | \nSite 31-2 | \n
Related datasets:
\nice properties, snow pits, sea ice, ice optics
These observations are being analyzed in conjunction with those collected by personnel on the N.B. Palmer to yield a regional ice maps. The summary data from the observations on the Gould show substantial amounts of open water were encountered during cruise as was evident from a large amount of time spent in the vicinity of the southern end of Adelaide Island where the reoccurring polyna predominated. Because of these operations, the operations are highly biased and significant editing of observations has to occur to account for reoccurring observations in the same region. Such editing and analysis are underway. Despite these known biases, the observations yield useful information in regards to the types of ice encountered. For instance, the average estimated ice thickness on ridged ice types was 54 cm while the average level ice thickness encountered was 38 cm (below). Snow thickness estimates yielded an average snow thickness of 11 cm with only 70.8% of the ice observed had snow (the remainder of the ice observed being nilas or young gray ice with new snow cover).
\nSummary statistics from sea ice observations aboard LMG01-06.
\n\u00a0
\n| Total ice concentration (%): | \n82.18* | \n
| Open water within pack (%): | \n17.82* | \n
| Avg. level ice thickness (total area) cm: | \n31.52 | \n
| Avg. level ice thickness (ice area) cm: | \n38.35 | \n
| Fraction of surface area ridged: | \n0.05 | \n
| Avg. ridged ice thickness (total area) cm: | \n44.5 | \n
| Avg. ridged ice thickness (ice area) cm: | \n54.15 | \n
| Avg. snow thickness (total area) cm: | \n9.05 | \n
| Avg. snow thickness (ice area) cm: | \n11.01 | \n
| Avg. snow thickness (snow covered area) cm: | \n15.55 | \n
| Snow covered ice within pack (total area): | \n58.18 | \n
| Snow free ice within pack (total area): | \n24 | \n
| Percent ice with snow cover: | \n70.8 | \n
| Percent ice with no snow: | \n29.2 | \n
| \u00a0 | \n\u00a0 | \n
| Avg. albedo (total area) | \n0.55* | \n
\u00a0
\n*biased by repetitive polyna observations
\nSummary statistics for observations taken during the LMG02-05 cruise.
\n\u00a0
\n| Total ice concentration (%) | \n83.08 | \n
| Open water within pack (%) | \n16.92 | \n
| Avg. level ice thickness (total area) cm: | \n37.09 | \n
| Avg. level ice thickness (ice area) cm: | \n44.65 | \n
| Fraction of surface area ridged: | \n0.13 | \n
| Avg. ridged ice thickness (total area) cm: | \n81 | \n
| Avg. ridged ice thickness (ice area) cm: | \n97.5 | \n
| Avg. snow thickness (total area) cm: | \n11.09 | \n
| Avg. snow thickness (ice area) cm: | \n13.35 | \n
| Avg. snow thickness (snow covered area) cm: | \n16.4 | \n
| Snow covered ice within pack (% total area): | \n67.65 | \n
| Snow free ice within pack (% total area): | \n15.43 | \n
| Percent ice with snow cover: | \n81.43 | \n
| Percent ice with no snow: | \n18.57 | \n
| Avg. albedo (total area): | \n0.58 | \n
\u00a0
\n(from cruise reports, LMG0106, LMG0205)
\nBCO-DMO Processing Notes:
\nversion 1 changes (2009-05-13):
\n- added conventional header with dataset name, PI name, version date
\n-\u00a0modified parameter names to conform with BCO-DMO naming conventions
\nversion 2 changes (2020-01-22):
\n- changed lonitude values to negative for West locations
\n- changed date format from m/d/yyyy to yyyy-mm-dd