NEON and Texas A&M Consider Collaboration for Flux Data
View of a flux tower from below
December 2017
The atmospheric flux towers at NEON’s terrestrial field sites provide a rich set of data for examining the exchange of gasses and energy between the atmosphere, plants, and soil. Recently, researchers from the Texas A&M Department of Ecosystem Science and Management visited NEON’s CLBJ terrestrial field site outside Decatur, Texas to learn how NEON data could support their own research programs.
Surface-atmosphere exchange, also known as “flux,” is the process by which gases (such as carbon dioxide, nitrogen and oxygen) and energy (sunlight and heat) are passed back and forth between the atmosphere and soil and plant life on the ground. Understanding these exchanges, and the overall balance of chemical and energy exchange, is a foundational component of climate science. For example, local flux data tells researchers how much carbon dioxide trees and vegetation are absorbing from the atmosphere and whether the net exchange of carbon between the surface and atmosphere is positive or negative.
NEON terrestrial sites are equipped with sophisticated flux towers for collecting these measurements. Towers range in height from 26 to 279 feet, depending on the location, to allow measurement above the vegetation canopy. Suites of sensors mounted on the top, as well different heights along the tower, continuously collect a full profile of atmospheric measurements. These measurements include carbon dioxide concentration and flux, wind speed and direction, particulate mass and size, precipitation, direct and diffused radiation, air temperature, barometric pressure, and more to provide a detailed look at the microclimate around the tower. Like all terrestrial NEON sites, this tower is co-located with soil sensors and observational sampling plots. This integrated sampling approach supports ecosystem-level study of carbon dioxide, water vapor and energy fluxes as they cycle through the atmosphere, vegetation, and soil.
Texas A&M hopes to tap into the data collected at NEON sites as well as NEON’s expertise in the deployment of advanced sensor technologies for flux measurement. The Department of Ecosystem Science and Management is already engaged in flux measurement of their own. They currently operate two flux towers near Vernon, Texas and are planning to build several additional towers along a north-south gradient in Texas. Seven representatives of the department, including Department Chair Dr. Kathleen Kavanagh, visited the NEON CLBJ terrestrial field site on November 9 to learn more about NEON’s capabilities and discuss ways in which the organizations can collaborate.
The NEON towers offer some advanced instrumentation not available on Texas A&M’s current towers, including a Cimel sun photometer and a Picarro laser analyzer for precision measurement of carbon dioxide and water concentrations. Because instrumentation and data collection methods are standardized across NEON field sites, the data also allow for analysis and comparison between the Texas sites and other sites across the country.
Discussions between Texas A&M and NEON are ongoing. Texas A&M is considering using NEON data to supplement their own data collection. They are also looking at the possibility of standardizing the data collected at their own sites with NEON’s methods so that data between NEON and Texas A&M towers will be fully comparable. Using NEON’s tower data will allow them to expand their research programs without additional expenditures, and may allow them to build and operate fewer towers of their own.
The NEON flux towers are designed to provide extremely high quality, standardized eddy covariance data. These detailed data will help researchers build better climate models and understand how flux conditions are changing both locally and nationwide.
Building the network of flux towers has given the NEON team considerable expertise in this area, which they hope to share with Texas A&M and other researchers interested in studying surface-atmosphere exchange. NEON can also provide additional resources for researchers, including mobile truck-mounted towers that can be deployed to gather flux data in areas outside of NEON’s field sites. These towers are available to outside researchers through NEON’s Assignable Assets program.