Neon optimization examples

1. This material is based upon work supported by NSF’s National Ecological Observatory Network which is a major facility fully funded by the National Science Foundation
Christine Laney, Caren Scott, Kaelin Cawley
LTER ASM 2018, Pacific Grove, CA
October 2, 2018
NEON Optimization Examples
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2. 1: Alkalinity & Acid Neutralizing Capacity (ANC)
• Goal: Reduce budget, without major decrease in quality of our data products
• Alkalinity and Acid Neutralizing Capacity (ANC) are measures of the water’s ability to buffer
systems from changes in pH
▪ ALKALINITY: filtered water
▪ ANC: non-filtered (whole) water
• At each stream site, NEON measures both alkalinity and ANC 26 times per year
▪ 12 monthly
▪ 14 based on hydrology
• If particulates do not add to buffering capacity, ANC will be equal to ALK
• Can we reduce the sampling of ANC?
Contact: Caren Scott (cscott@battelleecology.org)
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3. How similar are ALK/ANC? Site ID
Mean Alk
meq/L
Mean
%Diff
ARIK 5.31 3
BIGC 0.60 5
BLDE 0.88 6
BLUE 6.20 3
CARI 0.60 5
COMO 0.19 10
CUPE 2.75 3
GUIL 1.69 5
HOPB 0.12 30
KING 6.24 3
LECO 0.09 14
LEWI 5.43 4
MART 0.30 10
MAYF 0.04 38
MCDI 5.60 5
MCRA 0.21 10
OKSR 0.56 7
POSE 0.86 5
PRIN 4.98 3
REDB 4.62 3
SYCA 5.26 4
WALK 2.05 3
WLOU 1.25 12
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4. How similar are ALK/ANC?
• Significant differences at 7 sites
• But the differences are so small,
are they ecologically meaningful differences?
• USGS defines appropriate reproducibility of replicates
▪ good indication of ecologically meaningful differences
• ONLY 1 site had differences greater than USGS threshold
▪ LECO
ALK
meq/L
USGS
cutoff
>4 5%
>0.02 &
<4 10%
<0.02 1 meq/L
Commissioning
Tests
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5. Is there a pattern to the differences?
• Even if overall the differences are small, is there a pattern?
• For example: Are differences are always greater in the spring?
▪ If they are, we can keep sampling both ALK and ANC in the spring
• Modelled the differences
▪ Total Suspended Solids—indication of particulates
▪ Specific Conductance—indication of hydrology
▪ Month—indication of hydrology
▪ Year
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6. Is there a pattern to the differences?
There are some significant predictors of the difference, mostly by month
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7. Recommendations:
• Very little difference between measurements of ALK and ANC
• Even when significant, the magnitude of the difference is smaller than what we
would find appropriate for replicate samples
• Of these small differences, some sites show that the differences are greater in
certain months
• We recommend reducing the ANC sampling
• Keep it at once a month to capture seasonality
• EXCEPT: LECO, significant difference that was greater than replicates should be
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8. 2. Reaeration Optimization
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Contact: Kaelin Cawley (kcawley@battelleecology.org)
Question
• Does collecting 6 reaeration experiments per year rather than 10 impact data
quality negatively?
• Physical reaeration is an important
component of enabling metabolism modeling
in aquatic systems
• Parts of an experiment:
1. Discharge measurement
2. Field measurements
3. Conductivity logger measurements
4. Tracer samples

9. Data Completeness
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10. Future Process Quality Checks
▪ Quarterly QAQC checks from HQ and service now ticket(s) and tasks for incomplete experiments
▪ Attempt to reschedule reaeration experiments if one or more components are not completed, e.g.,
HOBO files or discharge data missing or corrupt
▪ Follow-up with the external labs to ensure data is returned in a timely manner
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Future Data Quality Checks
▪ Develop relationships between physical reaeration
rates and stream discharge where possible using
the existing reaeration R package
▪ Target times of year when discharge is likely to be in
a range that isn’t well covered with existing
reaeration data
k600
versus Q

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