Raw tensiometer soil matric potential data, from Oct 2017-Jun 2020 in Manaus, Brazil

Author(s): Collins A; Newman B; Gimenez B; Wright C; Warren J

Site ID: BR-Ma2

Site Name: Manaus - ZF2 K34

Variables: Soil matric potential

Date Range: Oct. 26, 2017 - Nov. 9, 2020

Description: This data package contains raw output from two Campbell Scientific CR1000 data loggers each connected to three UMS T4e tensiometer sensors in Manaus, Brazil. Tensiometers at each data logger location were installed to depths of 10 cm, 20 cm and 50 cm below the ground surface for the purpose of measuring soil matric potential at each depth. “Station 3” tensiometers were installed at approximately 2°36'31.68"S, 60°12'34.70"W. “Station 4” tensiometers were installed at approximately 2°36'32.46"S, 60°12'34.92"W. The files “tensio3.edit.202109.csv” and “tensio4.edit.202109.csv” contain raw data (with invalid data removed). A text editor will be required to view the raw files in .csv (comma-separated values) format. Data processing was limited to: 1) Editing column headers for clarity; 2) Applying a correction that converts voltage read by the data loggers to pressure units (kPa); 3) removing all data greater than 50 kPa and less than -115 kPa; 4) Adding columns entitled “Caution.10cm”, “Caution.20cm” and “Caution.50cm” that contains values of either “NA” or “Caution”, the latter of which is applied when data exceeds the manufacturer reported data validity range of less than -85 kPa to suggest use of these data with caution; 5) Adding columns entitled “Invalid.10cm”, “Invalid.20cm”, and “Invalid.50cm” that contains values of either “NA” or “Invalid”, the latter of which is applied when data accuracy is deemed compromised due to the introduction of air bubbles into the instrument. Data marked “Invalid” may still indicate general trends of wet/high matric potential and dry/low matric potential, but values are inaccurate and dry/low matric potential values are likely not low enough. Wet/high matric potential values are likely to be more accurate than dry/low matric potential values; 6) Data format changed from .dat to .csv. This research was performed as a part of the NGEE Tropics project, which aims to advance model predictions of tropical forest carbon cycle responses to a changing climate over the 21st Century.

QA/QC: Full QA-QC

Methods Description: The following are the installation and maintenance methods for each station. Station 3: UMS T4e probes connected to Campbell Scientific CR1000 datalogger 2017 October 23: One trench was dug with a shovel, gradually deepening to 50 cm deep. All three probes were inserted at an approximately 45 degree angle, which results in 0.35 kPa offset (already accounted for in these data), at depths below ground surface of: #1 = 10 cm (T4e SN 05508), #2 = 20 cm (T4e SN 05506), #3 = 50 cm (T4e SN 05503). 2018 October 18: Tensiometers were refilled with degassed DI water at approximately 1015 am 18 October 2018. The 20 cm installation probe was carefully removed and replaced during refilling. The 10 cm and 50 cm installation probes were not removed but refilled in place. The 10 cm and 20 cm probes displayed highly variable data after refilling. Due to concerns of over-pressurizing during refilling, the technique was modified for the 50 cm installation to inject water much more slowly and data seemed to stabilize more quickly. Station 4: UMS T4e probes connected to Campbell Scientific CR1000 datalogger 2017 October 23: One trench was dug with a shovel, gradually deepening to 50 cm deep. All three probes were inserted at an approximately 45 degree angle, which results in 0.35 kPa offset (already accounted for in these data), at depths below ground surface of: #1 = 10 cm (T4e SN 05509), #2 = 20 cm (T4e SN 05507), #3 = 50 cm (T4e SN 05510). 2018 October 18: Tensiometers were refilled with degassed DI water at approximately 1215 pm 18 October 2018. All 3 tensiometers were refilled slowly and successfully. The 50 cm installation was reading out of range values (+250 kPa) and appeared to continue to give out of range values after refilling. 10 cm and 20 cm installation probes looked to be within the appropriate measurement range. Both Stations: Data was downloaded approximately monthly, and systems were checked for power and basic functionality. Chronological gaps in the data record either indicate power outages during which data was not recorded, or periods when all data for a given record (TIMESTAMP) was invalid as per referenced QA/QC procedures.

Access Level: NGEE Tropics

Originating Institution(s): Los Alamos National Laboratory

Sponsor Organization(s): None

Contact: Collins, Adam - Los Alamos National Lab (Acollins@lanl.gov)

Version: 1.0

Dataset Citation: Collins A; Newman B; Gimenez B; Wright C; Warren J (2022): Raw tensiometer soil matric potential data, from Oct 2017-Jun 2020 in Manaus, Brazil. 1.0. NGEE Tropics Data Collection. (dataset). https://doi.org/10.15486/ngt/1884391

Acknowledgement: Funding for NGEE-Tropics data resources was provided by the U.S. Department of Energy Office of Science, Office of Biological and Environmental Research.

This are no dataset references available.