Onnuri
R/V Onnuri

Ceilometers are ground-based remote sensing sensors that measure cloud ceilings and vertical visibility. They utilize a laser or another light source to detect backscatter from clouds, precipitation, and aerosols. Ceilometers provide detailed and precise measurements under all weather conditions and are cost-effective to operate. They are commonly used in boundary layer and cloud research.

The Cloud Aerosol and Precipitation Spectrometer (CAPS) is an in situ airborne spectrometer manufactured by Droplet Measurement Technologies. It combines the Cloud Imaging Probe (CIP), the Cloud and Aerosol Spectrometer (CAS), and the Hotwire Liquid Water Content (LWC) Sensor into a single instrument. CAPS measures the size distribution of aerosol, cloud, and liquid droplets for particles between 50-1600 μm in size, with a time resolution of 1 Hz. It can also capture images of cloud particles and provide measurements of temperature, pressure, and LWC.

Thermo Scientific Gas Analyzers are in situ gas analyzers manufactured by ThermoFisher Scientific. They provide precise measurements of various trace gases such as ozone, carbon dioxide, carbon monoxide, and sulfur dioxide. Thermo Scientific Gas Analyzers can be deployed on aircraft, research vessels, and ground-based platforms.

The Pandora Spectrometer System is a ground-based UV-VIS spectrometer designed to measure column amounts of trace gases in the atmosphere. It employs total optical absorption spectroscopy for retrievals of ozone, nitrogen dioxide, formaldehyde, and other trace gases. Pandora operates within the 280-525 nm spectral range at a resolution of 0.6 nm. It can perform both direct sun and all-sky radiance measurements, with an overall measurement time of 80 seconds. Pandora is part of a network of identical instruments called the Pandonia Global Network.

The Spectral Aerosol Extinction (SpEx) is a ground-based in situ spectrometer that measures ambient aerosol extinction. It is a modified aerosol extinction differential optical absorption spectrometer (AE-DOAS) with faster data acquisition and increased sensitivity. It measures aerosol extinction in the 300 to 700 nm wavelength range at a spectral resolution of about 0.7 nm. SpEx provides intensity spectra every 125 seconds and aerosol extinction every 250 seconds.

Generic-Chemistry Related Sensors (Gen-Chemistry) refers to non-specific instruments on a platform used for atmospheric chemistry measurements. These are typically in situ analyzers that measure various chemical compounds such as trace gases, halocarbons, volatile organic compounds, nitrates, aerosols, and other chemical species. Measurements can include mixing ratio, composition, particle size, optical properties, and particle size distribution.

The Tricolor Absorption Photometer (TAP) is an in situ optical sensor produced by Brechtel Manufacturing, Inc. It measures aerosol black carbon and light absorption by light transmission through a filter. It detects light absorption at three wavelengths: 467 nm, 528 nm, and 652 nm, providing data every second. TAP has been used for both ground-based and airborne observations.

Nephelometers are in situ optical sensors that can be airborne or ground-based. They measure the total scattering and backscattering of aerosol particles in the atmosphere. Nephelometers operate at three wavelengths: 450 nm, 550 nm, and 700 nm, with a typical time resolution of 1 Hz.

Sunphotometers are passive optical sensors that measure the amount of sunlight. They are pointed directly at the sun to measure direct sunlight and not sunlight scatter from aerosols. These measurements can be used to determine the aerosol optical depth by following Beer’s Law. Sunphotometers have been deployed on aircraft, research vessels, and field sites for aerosol research and monitoring.