Goal

The goal of the course project is for you to organize and prepare a report and preliminary analysis for the physical oceanographic data collected in Saanich Inlet. The emphasis will be on presenting the data and a rough qualitative and quantitative (where possible) analysis.

Background Reading

• Gargett et al 2003
• Manning et al 2010

Saanich Inlet Data Analysis

The project is to write a short cruise report detailing the observations made in Saanich Inlet. You will organize the data and make plots of the results. Some comparison with previous data is required. Any interpretation of the results will be welcome.

Getting data…

The data will be in a database at:

http://web.uvic.ca/~sarahjt/OSM/OSMCruiseData/

ctd :

• Individual CTD casts are named by station “S4, S5…”
• A 1-m vertical grid of the CTD casts: CtdGrid.mat
• The variables should be self explanatory. One exception is cgrid.alongx, which is an along-inlet co-ordinate system that is useful if you want to plot x,z,T plots (for instance). This has varied a bit over the years, and for 2016 is the distance from the head of the inlet. Other years it has been distance from S4. Sorry for the confusion, but distance from S4 is not a very good co-ordinate system if you don’t always do the same line. To correct, you need to find the cast with S4 data in it and subtract its value of cgrid.alongx from the rest to compare with other years.

Hallam:

• This year we have data from the UBC Hallam lab of monthly CTDs from 2015 to the present. They are collected near S4, and are extremely valuable in putting the data sets we collect into context. Note that their fluorometer has issues.

BPS:

• Last year we had Buoyed Profiler System data from Ocean Networks Canada. There is a map at http://www.oceannetworks.ca/installations/observatories/salish-sea/saanich-inlet showing its location. The CTD and Oxygen data from this profiler is collected usually 4 times a day, though there are data gaps. I have binned these into 1-day bins and interpolated over most gaps to give a nice time series. How does this data fit into your observations of the along-channel sections?
• http://dmas.uvic.ca/DataSearch?location=YPVP
• Slides about BPS Courtesy D. Riddell, ONC

Introduction

Write a brief introduction to your report. State the objectives of the cruises and what scientific questions they were designed to answer.

Methods and Site

Describe what vessel was used and what instrumentation was aboard. Be as specific as possible, including model numbers and any specifying information. Processing methods should be described at this point: i.e. if you bin the CTD data onto 1-m depth bins, this would be the place to mention it.

Also describe where the cruise went. This will be done with a cruise track over a plot of bathymetry. Include an indication of when and the ship was at different positions. The Inlet location should be indicated on a larger regional map as well. Below you are asked to compare with previous seasons and other years. Indicate which station(s) you are using to make this comparison.

This section is short!

Tides

Load bottom pressure data from VENUS for a month centered around the cruise. Also upload tidal predictions from IOS. Indicate where our cruise was. How well did the tidal prediction do? What are the differences and similarities?

Indicate where the data collection falls in the tidal phase and spring-neap cycle.

Local Weather

What was the weather like that day? At least mention. Ask your classmates for the weather on their leg. Or, download the met data from

http://web.uvic.ca/~sarahjt/OSM/OSMCruiseData/RegionalData/

Observations

The overall goal here is to compare our new data and put in context with different timescales in the Inlet.

Multi-year comparison

UVic visits Saanich Inlet almost every year in July since 2007. A fun comparison is to look at the data from station S4 and/or S5 for those years and see if there are any changes. Particularly focus on the deep water as the surface water is quite variable. Are there any years that are anomolous in any of the properties, and are there reasonable explanations for this?

Seasonal comparison

Similarly, we visit at different times of year. Is the inlet different in Jan, June, and July? Again, be careful about focusing on the near-surface data. The BPS data (see above) was collected from Jan until now, and can give the best picture of the inlet’s state over most of the year. How representative were the CTD casts collected at other times of year? Did they happen to catch an interesting event? What “events” can you see in the BPS data? Again, I suggest you strongly focus on the deeper water, though the upper water is interesting as well.

Cruise CTD Section

We ran from the Haro Strait to Saanich Inlet in 201407, 201509a, 201510, 201609a, 201609b, 201610, 201709, 201709b, and 201710. Plot the sections, preferably in space. Make sure to indicate salinity, temperature, O2, and fluorescence (the radiometer is less useful), and from that density. How and where do the water masses change in Satellite Channel? Preference would be to focus on 2017 data, but you are free to look at the previous cruises as well to compare and contrast.

General presentation hints:

You may also want to look at the O2 data. You’ll likely cover this in your other classes, but while you have the plotting routines made it is pretty easy to go through and make another set of plots.

For the CTD data, pcolor and contour are sometimes good. It is also sometimes more helpful to simply plot vertical profiles. i.e. to compare July 2007 to July 2014 it might be most effective to plot profiles of T at S4 in 2007 and J1 in 2010 on the same plot, but colour them uniquely. Similarly with S.

A very useful technique for determining water masses is a plot of T on the y-axis, versus S on the x-axis. You can do the same with O2 versus T or S (Flu isn’t as interesting).

Be judicious in your plots and comparisons. We don’t need to see all the data in each report. Tell a story with the data.

Make sure your colormaps and axes limits are meaningful. The surface water varies a lot. If you want to talk about that, that is great, but be prepared to make another plot that zooms in on the deeper water that doesn’t have as much variation.

Summary and discussion

Summarize the findings. How did the observations conform to your expectations and what surprises did you find? How did they agree with previous measurements published by other authors (briefly!). Feel free to speculate on what mechanisms are causing the observations you are seeing. This section may be a few subsections where interesting tidbits from your analysis above are discussed in more detail, perhaps with a speculative air.

Format

You will each prepare a separate report. You may use the software package of your choice, but be sure to hand in a PDF of your final report.

All sections should be identified with clear headings, in bold.

I don’t require a bibliography, but if you prepare one put it at the end. Make sure to use an Author/Year citation style in the text i.e. “Gargett et al. (2003) found that deep water renewal into the inlet was episodic….”

Figures are the heart of this report. They should all be legible. Each should have a caption including a figure number. Most software packages have ways of keeping automatic counters of figure numbers. In the main text, reference should be made to figure numbers.

Figures must include axes labels, legends, and colorbars. Text annotations on the figures are sometimes useful.

Grading:

The goal is to present the data as clearly as possible. This requires figures, figure captions, and some prose. The grading is as follows:

• Prose (out of 11)
  • Introduction
  • Description of the experiment
  • Explain the data in the figures
  • Compares the data sets
  • Attempts to explain relevant physical processes
  • Refers to published literature if relevant.
• Figures (out of 14)
  • Clear, properly labeled
  • Clear and concise captions
  • Explain the data efficiently