MV005
Meteorological data from the Discovery Tree at the Andrews Experimental Forest, 2015 to present

CREATOR(S): Christopher J. Still

PRINCIPAL INVESTIGATOR(S): Christopher J. Still

ORIGINATOR(S): Christopher J. Still

OTHER RESEARCHER(S): Youngil Kim, Elise Heffernan, Mark D Schulze, Adam Sibley, Adam M Kennedy

DATA SET CONTACT PERSON: Adam M Kennedy

METADATA CONTACT: Adam M Kennedy

MOST RECENT METADATA REVIEW DATE:

14 May 2019

KEYWORDS:

relative humidity, microclimate, wind direction, wind speed, air temperature, soil temperature, soil moisture

PURPOSE:

To understand whether and how the forest canopy is 'de-coupled' from the understory and connected to larger-scale climate processes, and thus might also be experiencing regional warming and drought and heat stresses. Also to demonstrate how canopy microclimate observations can advance fundamental biological understanding of canopy processes and properties and their linkages to atmospheric and sub-canopy dynamics.

METHODS:

Experimental Design - MV005:

Description: Sensors were placed at defined intervals along a 65m tall old growth tree. Observations were collected at 1 or 30 seconds (depending on sensor) and averaged over 5-minute intervals. One CR1000 data logger was used to collect and compute 5-minute statistics from the lower sensors while a CR23X configured as a PakBus logger was used to collect and compute 5-minute statistics from the upper sensors.

Instrumentation: See Instruments listed in Field Methods section

Field Methods - MV005:

Description:

The following environmental variables were observed at multiple heights in the discovery tree.

Air Temperature/Relative Humidity: Campbell Scientific; HC2S3; Calibration dates unknown; Accuracy Air Temperature +- 0.6 deg C, Relative Humidity between -+3% - 7% depending on temperature and RH, 5-minute average; Heights 1.5m and 56m. Chris Thomas fan aspirated shield.

Dew Point Temperature: Calculation on data logger; deg C.

Vapor Pressure and mean air temperature: Calculation on post processing; mb.

Vapor Pressure at dew point temperature: Calculation on post processing; mb.

Air Temperature: Campbell Scientific; 107; Calibration dates unknown; Accuracy =±0.01°C over measurement range (CR1000), < ±0.5°C over measurement range (CR23X), 5-minute average; Heights 10m, 20m, 30m, 40m. Chris Thomas fan aspirated shield.

Leaf-wetness: Decagon Devices; output range 250 – 1500mV, operating temperature -20 deg C to 60 deg C. No accuracy data given; Heights 1.5m, 10m, 20m, 30m, 40m, 56m, units; mV.

Sonic Wind Speed/Direction: Vaisala, WAS425 (new code WS425); Unknown calibration dates; Accuracy +- 0.135 m/s or 3 % of reading, whichever is greater and +- 2 deg for wind speed over 1 m/s), 5-minute average; Heights 1.5m, 50m.

Instrumentation:

Instruments were mounted on the north side of the tree, approximately 30cm from the trunk. See field methods description section for a list of instruments deployed.

Dataloggers used: Campbell Scientific Inc,; CR1000, Calibration dates unknown; Accuracy Analog voltage accuracy +- (0.06% of reading + offset) at 0 deg to 40 deg C. Campbell Scientific Inc,; CR23X, Calibration dates unknown; Accuracy Analog voltage accuracy unknown.

Statistics - MV005:

Description: 5-min data are averages of 1 (wind speed and direction) or 30 second (everything else) samples.

Processing Procedures - MV005:

Description: Data were post-processed using GCE Data Toolbox for Matlab version 3.9.7b. Development of the GCE Data Toolbox for MATLAB was supported by the National Science Foundation under grant numbers OCE-9982133 and OCE-0620959.

Quality Assurance - MV005:

Description:

The data were checked for erroneous values using automated quality assurance checks. Missing timesteps were added and if gaps were less than 5-minutes, estimated values were added. Duplicate timestamps were identified and the second instance of duplicate row was deleted.

Manual data screening was undertaken using flags created by the GCE toolbox referenced in the processing procedures section. In most cases data records flagged as "Q" (questionable) or "I" (impossible) were replaced with NA values. Any NA value that was introduced into the dataset in the screening process has a corresponding flag value of "R", which stands for removed.

SITE DESCRIPTION:

Old-growth forest and an adjacent secondary-growth forest.

TAXONOMIC SYSTEM:

None

GEOGRAPHIC EXTENT:

Discovery Trail at the HJ Andrews Experimental Forest Headquarters

ELEVATION_MINIMUM (meters):

436

ELEVATION_MAXIMUM (meters):

436

MEASUREMENT FREQUENCY:

5 minute intervals

PROGRESS DESCRIPTION:

Active

UPDATE FREQUENCY DESCRIPTION:

continually

CURRENTNESS REFERENCE:

Observed