Physico-chemical Oceanographic data analysis

Most Israt Jahan Mili, School for Marine Science and Technology, University of Massachusetts-Dartmouth.

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Summary

This activity is a part of the course that can be used for either physical oceanography (CTD data profiling) or chemical oceanography lab exercise. This is included with the real-time field sampling data that was previously published as a data article in 2021. Also, it can be used as secondary data for manuscript preparation and publication with proper citation, or can be utilized to become familiar with those features.

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Learning Goals

Upon completion, the learner will be able to work with a '.mat' or '.csv' or '.xlsx' file to import into MATLAB. They will be able to create new variables and run a script. Will be able to plot figures of the vertical line graphs and describe how the profiles of temperature, salinity, density, fluorescence, dissolved oxygen, and turbidity change with the depth of the water column. Will become familiar with the range of such parameters in the aspects of a subtropical region through the nutrients data files.

The in-situ data will be shown in this aspect using MATLAB, which will provide the learner with a more detailed understanding of how they are dispersed. Consider other factors that might affect such variations when you write your report.

Additionally, it would be beneficial to learn how to write with field data, gain some understanding of how the data is gathered, and become accustomed to the tools.

Context for Use

#The best place to introduce and carry out this activity is at the undergraduate and graduate levels of universities, studying oceanography, environmental science, and marine science.

#This can be used as a component of a course on the physico-chemical characteristics of ocean research. The MATLAB exercise scripts can be completed in 2-3 full classes of 40–50 minutes with only one station's worth of data; however, if someone wants to use all of the data for their manuscript, it may require more work depending on the theme they choose.

#This might benefit from some earlier, more fundamental familiarity with handling and using MATLAB, but it's not necessary.

#Some theoretical understanding of those properties, such as what they are and how they vary depending on the climate, ocean, and other geographical factors.

#This task is also easily accomplished using different tools and settings.

#Access to MATLAB. This may already be installed on a person's computer or may have been on a computer in a lab or classroom. To work more effectively, it would be helpful to understand what a command window is, as well as the workspace, editor, current folder, mat file, script, and live script.

Description and Teaching Materials

With this activity, first you will prepare images using MATLAB and second, write a report with those images. As attachments, there is one compressed 'Data files', one '.m' file as script and two PDFs (one is a guide to import data into MATLAB and another one is a guide to write the report) . Download all attachments and place them in a designated working folder. Under 'Data files' there are '.mat' file, '.xlsx' file and '.csv' files. Using the PDF brief guide (explanation of how to import '.csv' and '.xlsx' files into a MATLAB environment), import the data into MATLAB. After the data has been successfully imported, open and run the MATLAB script ('.m' file). When you are successful in running the script with the imported data, you will end up preparing three figures as figure1, figure2 and figure3. Read through the report writing guide as PDF to prepare other images as stated. Save desired images in a 'JPEG' form. (Note: To avoid difficulties locating the folder/file path in the MATLAB environment, you must keep all of those files, including the data and the script, in the same folder). Note that with the prepared script ('.m' file) you will be able to prepare images for one station. However, as you will be able to import data into MATLAB, therefore follow those steps to prepare images for other stations and modify the script as required before running the script.

When you are done with the preparation of the required figures, follow the instructions for writing the report and submit it for assessment.


Direction to import data (Acrobat (PDF) 437kB Nov5 23)
Report writing directions (Acrobat (PDF) 698kB Nov5 23)
Script (Matlab File 3kB Nov5 23) 
Data file (.mat file) (Zip Archive 35kB Nov5 23)

Teaching Notes and Tips

It is necessary to introduce students to some fundamental MATLAB terminology. Finding the file directory in MATLAB to find the datafile can occasionally be difficult. As a result, it is advised to keep everything in the same working folder and access from there.

Assessment

Learners will be able to play with various data file formats, import the data, run the scripts, and create the figures. Look into the flow of writing the report and the capability of writing the description. Please cite these data sources properly when using them.

References and Resources

This activity's data was published as a data article in the "Data in Brief Journal" in 2021 and is also accessible online. Therefore, using this should include the proper citation, which is provided below:

Mili, Most Israt Jahan, Md Kawser Ahmed, Md Masud-Ul-Alam, Md Hasnain, Md Ashif Imam Khan, Rupak Loodh, Abdullah-Al Hasan, Kazi Belayet Hossain, and Sultan Al Nahian. "In-situ datasets of important physical and bio-chemical parameters in the continental shelf of the northern Bay of Bengal." Data in Brief 35 (2021): 106947.