North Atlantic CTD Casts with Sensor Profiles from 2011 Cruise

NOAA NCEI provides 100 CTD (Conductivity, Temperature, Depth) casts collected during the R/V Knorr cruise KN200-2 in March 2011 north of the Flemish Cap. The dataset includes raw and derived oceanographic variables from primary and secondary sensor suites, processed and binned to 1-decibar intervals. Data collection and processing were performed by NOAA using a SeaBird SBE911+ system and proprietary software.

Use Cases

• Modeling water column stratification by analyzing potential density (sigma-theta) profiles derived from temperature and salinity.
• Calibrating secondary sensor suites against primary sensors using the quality flags (PRIMARY, SECONDARY, BOTH GOOD) for temperature and conductivity channels.
• Studying biological activity through correlations between chlorophyll fluorescence, beam transmission, and turbidity measurements.
• Analyzing sensor response times by applying the documented time delays (e.g., oxygen voltage advanced by 4 seconds) to time-series data.
• Investigating upper ocean dynamics using casts limited to the upper 1000 decibars versus full-water-column profiles.

Strengths

• 100 CTD casts provide multiple spatial samples from the North Atlantic region.
• Data includes both raw sensor values (e.g., temperature, conductivity) and derived variables (e.g., potential temperature, salinity, oxygen concentration).
• Processing details are documented, including specific time delays (e.g., 0.011s for primary conductivity) and filter parameters (7-scan median filter).

Limitations

• Sample size is limited to a single cruise in March 2011, lacking temporal diversity.
• Geographic coverage is restricted to the region north of Flemish Cap in the North Atlantic Ocean.
• Some casts only cover the upper 1000 decibars, not the full water column.

Provenance

Source

NOAA National Centers for Environmental Information (NCEI).

Collection Method

Data collected using a SeaBird SBE911+ CTD system sampled at 24 Hz, processed with SBEDataProcessing-Win32 software, and averaged into 1 dbar bins.

Time Range

March 2011.

Freshness

Data is from a single collection period concluding in March 2011.

Geography

North Atlantic Ocean, region north of Flemish Cap.