1. QC Challenges of Collecting
Time-Continuous Water
Quality Data:
PacIOOS Water Quality Buoy (WQB) Data QC
by
Michael Tomlinson & Eric De Carlo

2. Handout &Outline
 Handout contains most data products in presentation
 Overview of Pacific Islands Ocean Observing System
 PacIOOS water quality components
 Presentation focuses on the NOAA/PMEL MapCO2 /
PacIOOS specifically Water Quality Buoy data QC
 Manual data processing & QC (different time scales)
 Annual (and beyond) QC & data adjustment with
Aquarius® software
 Independent data (& estimate) validation
 Final data release
 What have we learned from 5 years of monitoring?

3. IOOS – National Ocean Observing
PacIOOS

4. PacIOOS

5. What does
PacIOOS do?
 Data Collection & QC
 Data Aggregation
 Data Visualization
 Real-time Warnings
 Provides Research Data
 Outreach/Communication

6. Examples of Applications
Understanding Ocean Acidification
Assessing the effects of storms on coastal
water quality (e.g., Tomlinson et al., 2011)
Water quality monitoring & sounding “all
clear” after tsunamis (e.g., Fiedler et al., 2014)
Impacts of groundwater / surface water on
coastal marine ecosystems

7.  NOAA/PMEL MapCO2/
PacIOOS WQBs (T, S, O2, CO2,
pH, nitrate, turbidity,
chlorophyll)
 Nearshore Sensors (T, S,
turbidity, chlorophyll)
 Kilo Nalu Observatory (tides,
waves, currents, acoustic
backscatter, T)
 Autonomous Underwater
Vehicle (bathy, currents, T, S,
chlorophyll, optical
backscatter)
 Synoptic manual event-driven
sampling
 NOAA/NWS Met Stations &
Rain Gages
 USGS Streamflow Gages
 NOAA/NOS Tide Gages & Met
Stations
 HIDoH Beach Monitoring
 NOAA/NDBC Open Ocean
Data Buoys
 Satellite Imagery
PacIOOS Water Quality Components

8. Water Quality Component Locations

9. NOAA/PMEL MapCO2/PacIOOS WQB Sensors
Sensor Variable
SBE16plus
V2 SEACAT®
Temperature
Salinity
Pressure
SBE63 DO® Diss. Oxygen
WET Labs
FLNTUS®
Chlorophyll
Turbidity
ISUS-V3® Nitrate
SeaFET® pH
LI-COR CO2® CO2

10. Data Processing & QC Flowchart
Figure 1

11. Twice-Daily Checks

12. Twice-Daily Checks (continued)
Gaps in the WQB record on
the website that did not
exist (see graph below);
caused by a problem with
the Data Turbine

13. Manual Processing (every 3 days)

14. Monthly QC Check

15. MathCAD® Check of Spreadsheet
Coefficient Check
Check Spreadsheet Calculation

16. Monthly Time-Series Plot

17. WQB Data QC 1 Year & Beyond
Aquarius "whiteboard" used to QC and adjust, as
necessary, data from the PacIOOS WQBs. In addition to
the WQB data, other data are used as surrogates to
help QC the data and guide any necessary
adjustments. The raw, adjusted, surrogate, and discrete
(C&CH) data are plotted as time-series.
Figure 2

18. Partial Aquarius® Whiteboard (close-up)

19. Rare Adjustment to Salinity Data
Raw Data
Adjusted Data
Note: Adjusted data are always flagged as ESTIMATES
Figure 3

20. Not So Rare Adjustment of
SBE43® Dissolved Oxygen (DO) Sensor
Figure 4

21. WET Labs FLNTUS® Chlorophyll &
Turbidity Sensor – Ultimate Challenge
Figure 5

22. Great when the sensor is working …
Figure 6

23. … a real challenge when it isn’t working
Figure 7

24. Final Adjusted Turbidity & Surrogates
Figure 8

25. Chlorophyll had its own challenges …
Figure 9

26. … but adjustable trim correction …
Figure 10

27. … salvaged some of the data!
Figure 11

28. Problems Evident After 1+ Years
(SBE43® Membrane DO Sensor)
Sensor began to drift immediately after deployment and continued
throughout the entire deployment period, regardless of the time of
year. SBE conceded there was a problem but cannot explain it.
Figure 12

29. Correcting the SBE43® DO Problem
Figure 13

30. Independent Data QC Check
C&CH NPDES
Receiving Water
Monitoring Station
Figure 14

31. Raw &
Adj.
WQB
Data
and
C&CH
NPDES
Data
Figure 15

32. Figure 16

33. Master PacIOOS WQB Spreadsheets

34. PacIOOS Water Quality Webpage

35. What have we learned in 5 years?
 QC must be conducted at different time scales
 Need one extra suite of sensors for annual servicing
 Some sensors (e.g., SBE43® DO membrane sensor)
do not work well in shallow, subtropical water
 Although expensive, need another suite of sensors with
comparable precision & accuracy for servicing checks
 Data QC is not part-time job nor can it be automated …
 … unless we emulate the National Data Buoy Center &
have redundant sensors (very expensive)
 Routine monitoring provides valuable research data,
e.g., tsunami water quality effects (Fiedler et al., 2014)

36. Questions & Contact Information
www.pacioos.org
Michael Tomlinson
UHM Oceanography
Flagstaff, AZ
mtomlins@hawaii.edu
928-266-2236 (cell)