Northwest Dive Club

How much do you think the water temperature changes over the course of a year in Puget Sound?

During the last 45 months I have collected 247 water temperature measurements using the same Shearwater Petrel 2. When I dive multiple times per day at the same site, I only use one sample for that site on that day. Turns out that the temperature in Puget Sound goes from a low of 47 to a high of 55 (°F). Here is a graph of the data I've collected.

Cheers, John

That's a pretty solid seasonal plot. Nice work. How does it compare to historical data? Presuming this is aggregate data (pooled 4 yr data), how does it trend as a 4 yr plot? Undulations fairly similar? were you seeing fairly similar highs/lows over the time? (sorry to get data nerd...) If I teach a unit on oceanogrpahy again this year, mind if I use this plot (middle school science)?

Nice! My wife doesn't currently believe me that the water temperature fluctuates more than 1 or 2 degrees. I'll have to show here this (in a nice way of course!). Are these average or lowest temperatures per dive? I'm not sure how the shearwater records temps, but my oceanic computer saves the coldest temperature noted during a dive as the final temp. With the thermoclines this time of year it's always interesting to see the varying temperatures between the deeper and shallower sites.

The Shearwater records every 10 seconds. The numbers I use are the lowest temperatures recorded on each dive.

Yes, you can have the data I've collected. I have it both as a table in Word and in Excel. You can email me at johndo88@gmail.com and I'll send it to you. My data collection starts November 2015 to present (the first two dives in August 2019, but I'll be adding a third entry tonight).

johndo88- email sent. Thank you!

I am honestly surprised to see the data get up in the mid 50's; I knew it got into the 50's but wasn't expecting 55/56.

WARNING- I geek out below on data for a second. Read if you wanna geek out a bit.

Since this is similar depth records across the whole data set, and this is site specific, NOW I'm interested to see similar data trends from other locations under similar circumstances to compare. This kind of information is interesting on many levels, at least to me. Primarily if we consider local conditions as driving factors for local dissolved gases and availability of nutrients (from upwelling, etc) in a more intimate approach, one could do cross comparisons of different dive sites looking at similar currents/exchange rates and local animal life abundance. Essentially what I am saying is, we could generate a "Map" of "where and when" to track more trends in what we (as divers) are seeing at a macro level and correlate it to other factors. I'd be willing to bet there are smarter people than me that are already thinking about this stuff, they just don't have the diver power to get the site specific data coverage.

Hmmmm... I've got a scientist friend at NOAA... I'm going to reach out to her... could literally crowd source the data from the dive community? This would mean we'd have to know the calibration range of/ calibrate the temp sensors on the dive computers to make the data as accurate as possible... hmmm...

We as a local dive community have piles of this data, presumably sitting in computer records? (Unless of course it's been dumped as not relevant...) Thinking of the amount of literal data: times, dates, sites, depth ranges, and variances, this could be interesting to load into a graphics system to show the temperature fluctuations as a heat map over seasonal time in combination with the known tide exchange rates. Hmmm....

Was your max depth the same on every dive?

johndo88 wrote: ↑Thu Aug 15, 2019 9:38 am How much do you think the water temperature changes over the course of a year in Puget Sound?

During the last 45 months I have collected 247 water temperature measurements using the same Shearwater Petrel 2. When I dive multiple times per day at the same site, I only use one sample for that site on that day. Turns out that the temperature in Puget Sound goes from a low of 47 to a high of 55 (°F). Here is a graph of the data I've collected.

Cheers, John

Laura, not at all. The dives were however at recreational depths (I do not include deep technical dives in this list).