Small Optical Particle Spectrometers (POPS)

AGENCY: National Oceanic and Atmospheric Administration (NOAA), Office of Atmospheric Research (OAR), Chemical Sciences Lab (CSL) DESCRIPTION This is a Sources Sought notice. This is NOT a request for quotes or proposals. This notice is for informational and planning purposes only and does not constitute a solicitation. The Government will not pay for any information submitted in response to this Sources Sought notice.

NOAA CSL is seeking to identify potential sources capable of providing 10 small optical particle spectrometers (Portable Optical Particle Spectrometer (POPS)) for the measurement of stratospheric aerosol size distributions using balloon sondes. SCOPE OR MISSION The instruments are needed for an ongoing project involving the systematic measurement of stratospheric aerosol number and size distributions.

These measurements will be conducted using small (weather) balloon sondes launched from Boulder, CO and other global sites, to characterize the baseline and variability of stratospheric aerosol microphysical properties. This project is a key component of the congressionally funded NOAA OAR Earth Radiation Budget initiative. BACKGROUND Stratospheric aerosol is a critical component of the climate system.

Improved observations of stratospheric aerosol microphysics and variability are necessary to enhance model representation of climate and ozone chemistry impacts resulting from changes in stratospheric aerosol. Furthermore, in situ observations are essential for validating and improving the interpretation of satellite remote sensing observations.

These measurements necessitate a miniaturized, research-quality instrument capable of detecting particles with diameters as small as 140 nm to accurately characterize the stratospheric aerosol size distribution. TECHNICAL SPECIFICATIONS Operational requirements for the optical particle spectrometer (OPC) instruments include:

Instrument Weight: < 1 kg Size: Smaller than 8" x 8" x 6" Power Consumption: < 6 W Minimum Particle Diameter Detection Limit: ? 140 nm Performance: Demonstrated performance at high altitude/low pressure. DELIVERY SCHEDULE NOAA CSL requires delivery of all 10 instruments by Sep 26, 2025. Partial deliveries following acceptance of the order are requested if permitted by production schedules. SUBMISSION INSTRUCTIONS Interested parties are requested to submit a brief capabilities statement (no more than 3 pages) demonstrating their ability to meet the requirements outlined in this notice. Submissions should include:

Company name, address, and primary point of contact information. A brief description of relevant experience and past performance in producing similar optical particle spectrometers. Confirmation of ability to meet the technical specifications. Anticipated lead time for production and delivery of 10 units. Any questions regarding this Sources Sought notice. Please submit all responses electronically to Elliott Waxman (elliott.waxman@noaa.gov) by Aug 8, 2025. This Sources Sought notice is for market research purposes only and does not commit the Government to award a contract. All information submitted will be used for planning purposes only.