Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Data Files
• Parameters
• Instruments
• Deployments
• Project Information
• Funding

This alongtrack data set consists of a single file produced for each day of the LMG1110 cruise, from 11/2/2011 to 12/1/2011.  Data were obtained primarily by applying calibrations to raw data and decimating to whole point intervals.  However, several fields are derived measurements from more than a single raw input. 

IEDA has published a DOI for another version of this dataset: 'Underway Hydrographic, Weather and Ship-state Data (JGOFS) from Laurence M. Gould expedition LMG1110 (2011)' 10.1594/IEDA/318148

The LMG alongtrack data acquisition systems continuously log data from a suite of instruments throughout the cruise. 

For information about events and known problems with acquisition, see the Cruise Data Report.

BCO-DMO Processing Notes and Edits:  BCO-DMO obtained the data in .dat format and made the following edits: Space and tab delimiters were replaced with commas.  Values originally used to indicate null, unusued, or unknown values (i.e. "9999" or "999.99") were replaced with "nd".  Two columns that were labeled "Not used" were omitted from display (these were columns 11 and 20 in original .dat files).  Original time in format of hh:mm:ss was removed from display.  "time_gmt", "month_gmt", "day_gmt" and "yrday" were calculated and added to the display.

The Antarctic salp, Salpa thompsoni, is an increasingly important player in the vulnerable Antarctic Peninsula pelagic ecosystem. Observations of high abundance of Salpa thompsoni during the summer in the Southern Ocean suggest that this species is capable of rapid somatic and population growth, and frequently forms dense blooms under favorable environmental conditions. The proposed research will examine genome-wide patterns of gene expression, target gene expression levels, and patterns of population genetic diversity and structure of the target salp species. Our preliminary results and data analysis have provided a promising basis for transcriptomic studies of S. thompsoni in the Southern Ocean. The proposed next steps in our genomic/transcriptomic analysis of Salpa thompsoni are: 1) completion of a reference transcriptome as a basis for genome-wide analysis of gene expression; 2) whole transcriptome shotgun sequencing (RNA-Seq) analysis to characterize gene expression in relation to individual characteristics and environmental conditions; 3) quantitative real-time PCR (qRT-PCR) characterization and validation of gene expression for 10-20 top differentially-expressed genes; and 4) detection of strand-specific allelic variation at SNP (Single Nucleotide Polymorphic) sites to analyze clonal diversity and population genetic diversity and structure. We hypothesize that: 1) deep analysis of the Salpa thompsoni transcriptome will reveal significant associations among selected set of differentially-expressed genes and critical life history stages and events (e.g., ontogenetic maturation, sexual reproduction, senescence) of the salp; and 2) the species will show variable levels of clonal diversity and significant genetic differentiation among salp populations in different regions of the Southern Ocean. Samples will be obtained from research cruises during 2011-2013 in diverse regions of the Southern Ocean; dedicated sample and data collection will be carried out during a cruise of the R/V LM GOULD (LMG11-10) to the Western Antarctic Peninsula region in November, 2011. The significance of this effort lies in new understanding of the molecular processes underlying the complex life history and population dynamics of S. thompsoni in relation to the Antarctic pelagic ecosystem and extreme and variable environmental conditions of the Southern Ocean.

Most of the data from this project are available from the Marine Geoscience Data System (MGDS), part of IEDA and is available at http://www.marine-geo.org/tools/search/Files.php?data_set_uid=18148.