| Sensor Type (link to manual) | sensor_min | sensor_max |
|---|---|---|
| aquameasure | -5 | 35 |
| hobo | -40 | 70 |
| vr2ar | -5 | 40 |
| tidbit | -20 | 50 |
| hobo do | -5 | 40 |
Thresholds
Temperature thresholds were calculated from the historical Coastal Monitoring Program data. Preliminary quality control was applied to this data, and obvious outliers and data from freshwater stations were omitted.
Separate thresholds were calculated for each county due to expected and observed spatial differences in temperature (Figure 1; Figure 2).
In the future, it may be useful to resolve temperature thresholds by depth as well as county (or smaller spatial scales). However, the data becomes very patchy when grouped by depth, which could result in less useful thresholds values. Additionally, the same depth can represent a different part of the water column for different stations. For example, at the Barren Island station in Guysborough County, the 15 m sensor is near the bottom. In contrast, 15 m is in the top 20 % of the water column at Tickle Island, another station in Guysborough County.
Gross Range Test
Sensor Thresholds
The sensor thresholds were determined based on the associated manual (Table 1).
Table 1: Temperature sensor thresholds for the Gross Range Test.
User Thresholds
The mean and standard deviation were used to determine
The
It may be useful for other users to apply their own
Climatological Test
Figure 2 shows the monthly mean and standard deviation of temperature data for each county. Observations from all depths were pooled together. This resulted in high standard deviations for some counties, particularly in the summer months when temperature stratification is the strongest (Figure 2, Table 3).
The observations are normally distributed within each month (Figure 3), and so the mean and standard deviation were used to calculate the seasonal thresholds (Table 3).
Figure 3
Seasonal distribution of depth observations (binwidth = 2 °C). Dotted orange lines indicate the user thresholds.
Spike Test
For all counties, the distribution of the spike value is skewed right, and so several upper quartile values (90th, 95th, and 99.7th quartile) were evaluated to use as the
Figure 4 shows the distribution of the spike value of temperature observations (binwidth = 0.1 °C). There is a separate tab for each county. Dotted orange line indicates
Figure 4
Table 4: Spike thresholds for temperature.
Rolling Standard Deviation Test
For all counties, the distribution of the rolling standard deviation is skewed right, and so several upper quartile values (90th, 95th, and 99.7th quartile) were evaluated to use as the
The 90th, 95th, and 99.7th quartile values were each applied to the the raw data (no preliminary QC) and the results inspected. There were minimal suspect changes in rolling standard deviation for temperature, and so the 99.7th quartile was selected to avoid false positives.
Table 5: Rolling standard deviation threshold for temperature.