Pacific Oxidants, Sulfur, Ice, Dehydration, and cONvection

The PAN and Trace Hydrohalocarbon ExpeRiment (PANTHER) is an in situ airborne analyzer. It uses electron capture detection and gas chromatography techniques to measure various trace gases such as methane, peroxyacyl nitrate (PAN), and carbon monoxide. PANTHER has a sampling frequency of 60 to 120 seconds and has an accuracy of around 2% for most species except for PAN (10%). The development of PANTHER was funded through NASA’s Instrument Incubator Program and NOAA’s Climate and Global Change Program.

The 2D-Stereo Particle Probe (2D-S) is an in situ airborne optical imaging probe developed by SPEC Inc. The 2D-S uses two diode laser beams to produce stereo cloud particle images through linear array shadowing. Through the imagery, cloud particle size distribution, particle number concentration, and ice/liquid water content can be determined. It has a resolution of 10 µm and can measure hydrometeors in the 25-1280 µm range.

The Meteorological Measurement System (MMS) is an in situ airborne instrument used for measuring atmospheric state parameters. MMS provides high-resolution and accurate measurements of atmospheric pressure, temperature, and wind direction/speed immediately around the plane. Additional parameters can be derived such as potential temperature, true airspeed, turbulence dissipation rate, and Reynolds number. Measurements of all parameters are typically collected at a rate of 20 Hz.

The Cloud Particle Imager (CPI) is an airborne imager manufactured by SPEC Inc. CPI collects high-resolution (2.3 μm pixel size) images of cloud particles that pass through its sample volume. It uses a charge-coupled device (CCD) camera that operates at 810 nm to record images and can take up to 74 frames per second with a refresh rate of 40 Hz. The imagery from CPI can be used to derive microphysical properties such as particle size and habit.

The Fast Cloud Droplet Probe (FCDP) is an in-situ airborne cloud probe manufactured by SPEC Inc. FCDP measures the concentration and size of cloud droplets by detecting the amount of light scattered by the particles. It measures particles within the diameter size range of 1.5-50 microns and has a typical measurement frequency of 1 Hz.

The Printed Optical Particle Spectrometer (POPS) is an in situ spectrometer that measures particle size and number concentration. POPS is capable of flying on UAVs or balloons, and it collects a vertical profile of particle measurements. With a typical operating wavelength of 405 nm, POPS obtains observations roughly every second and measures particles ranging in size from 140 nm to 3000 nm.

The Diode Laser Hygrometer (DLH) is an in situ airborne hygrometer developed by NASA’s Langley Research Center (LaRC). It uses tunable diode laser absorption to measure water vapor in the atmosphere. DLH operates in the near-infrared region at around 1.4 μm and has a measurement frequency of 100 Hz. It can provide accurate measurements of water vapor even while flying through clouds.

This data will be added in future versions.

This data will be added in future versions

The Whole Air Sampler (WAS) is an airborne in-situ instrument that collects samples of air for analysis of trace gases, such as nonmethane hydrocarbons (NMHCs), Halocarbons, Alkyl Nitrates, and various sulfur compounds that are present in the troposphere. Air samples collected via the WAS then undergo gas chromatography and mass spectrometry to determine which gasses are present in the sample. The WAS collects samples every minute, which enables scientists to get a clear picture of the chemical composition of the environment as research aircraft pass through.

The NOAA Dual-Beam UV-Absorption Ozone Photometer (NOAA-O3) is an in situ optical balloon-borne and airborne instrument that measures ozone concentrations in the troposphere and lower stratosphere. It operates at the 254 nm wavelength allowing it to calculate the ozone number density due to the accurate ozone absorption cross section at that wavelength. It has a sampling rate of 2 Hz and a horizontal resolution of 100 to 200 meters at typical research flight speeds.

The Uncrewed Aircraft Systems (UAS) Chromatograph for Atmospheric Trace Species (UCATS) is an in situ airborne instrument suite that measures trace gases in the atmosphere. It consists of three separate instruments: a three-channel gas chromatograph (GC), a dual-beam ozone photometer (OZ), and a tunable diode laser (TDL) spectrometer. The GC measures nitrous oxide (N2O) and sulfur hexafluoride (SF6) every 70 s and measures hydrogen (H2), methane (CH4), and carbon monoxide (CO) every 140 s. The OZ sensor operates at 254 nm and provides ozone measurements every 10 seconds. The TDL spectrometer operates at 1370 nm and provides water vapor measurements every 1 s. UCATS was designed to be operated on UAS, but it has been deployed on piloted aircraft as well.

The NOAA Water instrument is a two-channel, closed-path, tunable diode laser absorption spectrometer developed to measure both water vapor and enhanced total water content (sum of water vapor and inertially enhanced condensed phase) in the upper troposphere and lower stratosphere. It was originally designed to fly on the NASA Global Hawk Unmanned Aerial Vehicle, but it can fly on any high-altitude aircraft. The detection cells within the instrument are operated at a constant temperature, pressure, and flow conditions to maintain a constant sensitivity to ingested water regardless of the environment that is being sampled. Calibration of the instrument can also be completed periodically on-board to ensure the instrument remains stable during flight.