9 Attachment 1 - SON 1305M323QNRMA0096.pdf

Attachment 1

Statement of Need

NR-MAC100-23-00545

1. Background and Purpose

National Oceanic and Atmospheric Administration, Air Resources Laboratory’s Atmospheric Turbulence and Diffusion Division (ATDD) conducts a targeted variety of intensive campaigns to further the understanding of the carbon, water, and energy balance in the atmospheric boundary layer.

After considerable scientific planning and collaboration among partners in the research community, fluxes of CO2, H2O, and energy, along with a multitude of meteorological variables, will be measured in the upcoming Fire Weather campaign in the Western US in 2023. The primary method for measuring these fluxes is the eddy covariance technique, coupling a fast 3D wind speed sensor with a scalar gas analyzer measuring ambient concentrations of CO2 and H2O at up to 20Hz.

Additional measurements will be made at the Chestnut Ridge forest site in East Tennessee, continuing a long dataset of fluxes for monitoring seasonal climate variations.

2. Scope and Objectives

Eight gas analyzers are needed for the Fire Weather experiment, in order to measure carbon, water, and energy fluxes beginning in Fall 2023. Coupled with sonic anemometers, fluxes will be derived using the eddy covariance technique. The fluxes will aid researchers, providing an invaluable dataset as part of the Fire Weather campaign. Four gas analyzers are also needed for the ongoing climate monitoring at the Chestnut Ridge site.

Two plant canopy analyzers are needed to determine the leaf area index (LAI) of forests, grasslands, or managed agricultural systems that comprise the land use in the footprint of the boundary layer supersites that will be installed to support the fire weather research. Information on the LAI is critical for use in NOAA’s models for fire weather predictions. Similarly, one LAI canopy analyzer is needed for the Chestnut Ridge site to continue the needed measurement at that site.

3. Technical Specifications

In order to perform the required eddy covariance measurements, open-path gas analyzers measuring ambient concentrations of CO2 and H2O at up to 20 Hz are needed. Each gas analyzer must be reliable (with 20 years of proven field history, showing build durability and quality component selection), accurate (1% of reading for both CO2 and H2O), and rugged (withstanding temperatures from -20 to 50°C). For the CO2 measurements, a zero drift of no more than ±0.3 ppm per °C is required, and for the H2O measurements we require that the zero drift is no more than ±0.05 mmol mol-1 per degrees C.

Additionally, the RMS noise at 5 Hz should be no more than 0.08 ppm and 0.0034 mmol mol-1 for CO2 and H2O, respectively, and the gain drift should be no more than ±0.1% and ±0.3% of the maximum for CO2 and H2O, respectively. Scientifically proven flux processing software with data storage capabilities, like the SmartFlux 3 system, is also required. The unit needs to be low power, less than 5 Watts and over the range of 10.5 to 30 VDC. Additionally, the analyzer needs to be omni-directional and low maintenance, able to run for a full year without needing a site maintenance visit. Finally, because engineering support is limited, a familiar ‘plug and play’ solution is required.

Attachment 1

The canopy analyzers must use a non-destructive method to easily and accurately measure Leaf Area Index (LAI) within forests, grasslands and croplands and will provide a necessary measurement for further understanding the eddy covariance fluxes. The analyzers must have a menu-driven interface, in which one can view GPS coordinates, LAI, standard error, apparent clumping factor, mean tilt angle, and sample size. In addition, the canopy analyzers must have the advantage of automatic logging, USB data transfer, and a memory capacity of at least 1.5 million readings.

4. Required Items – Brand Name or Equal

Part Number / Description Quantity

Li-Cor LI-7500DS - Open Path H2O/CO2 Analyzer 12

Li-Cor LAI-2200C - Plant Canopy analyzer 3

Li-Cor 392-16699 - Ethernet Cable (25-m) 12

Li-Cor 9975-056 - Power Cable 12

Li-Cor 7900-340 - Analyzer Mounting Kit 12

5. Delivery Schedule

Delivery anticipated 60 after receipt of order (ARO).

Delivery address:

U.S. Department of Commerce Atmospheric Turbulence and Diffusion Division (ATDD) 456 S. Illinois Ave., R/ARL1 Oak Ridge, TN 37830