Fire Influence on Regional to Global Environments and Air Quality

Generic-Atmospheric State (Gen-AtmsState) refers to non-specific instruments on a platform used for measurements of atmospheric state parameters. These are typically in situ sensors that measure temperature, pressure, humidity, and wind speed/direction. Types of atmospheric state instruments include thermometers, hygrometers, barometers, and anemometers.

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 Proton Transfer Mass Spectrometer (PTR-MS) is an in situ spectrometer used both on aircraft and ground, developed by the University of Innsbruck in Austria. It detects volatile organic compounds (VOCs) without the need for sample preparation at very low concentrations. PTR-MS employs chemical ionization mass spectrometry, enabling quick and highly sensitive VOC detection. It has a signal integration time ranging from 0.5 to 1 second.

NOx/NOxy is an in situ chemiluminescence instrument that measures nitrogen oxides and ozone in the atmosphere. It offers a spatial resolution better than 100 meters at typical DC-8 research flight speeds. NOx/NOxy can be used on ground-based, airborne, and shipborne platforms, enabling it to support various atmospheric chemistry and air quality studies.

The Aerosol Mass Spectrometer (AMS) is an in situ spectrometer developed by Aerodyne Research. It employs quadrupole mass spectrometry to measure aerosol chemical composition and properties. It can detect particles ranging from 40 nm to 1 micron in size and has a time resolution of up to 10 Hz. It can be installed on aircraft, research vessels, mobile laboratories, or other ground-based platforms.

The Harvard Hydroxyl Experiment (HOx) is an in situ laser-induced fluorescence (LIF) sensor developed by Harvard University. It uses LIF centered at 309 nm to measure hydroxyl radical (OH). The OH is then converted into its first electronic state using a tunable ultraviolet laser near 282 nm. The hydroperoxyl radical (HO2) is measured as OH after chemical titration with nitric oxide. HOx has a short integration time of less than 20 seconds.

Generic-Chemical Ionization Mass Spectrometry (Gen-CIMS) refers to a non-specific CIMS instrument on a platform. A CIMS is an in situ mass spectrometer that measures gas species by ionizing the molecules through chemical reactions. They provide measurements of trace gases, organic compounds, inorganic compounds, halogen species, and reactive nitrogen species.

The Ultra-High Sensitivity Aerosol Spectrometer (UHSAS) is an in situ spectrometer developed by Droplet Measurement Technologies. It can be used on both airborne and ground-based platforms to measure aerosol size distribution and concentration. UHSAS determines particle size by detecting the peak light signals from aerosol particles illuminated by a 1054 nm laser. It can sample particles in the 60–1000 nm size range and operates at a sampling frequency of 10 Hz.

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.

NOx/NOxy is an in situ chemiluminescence instrument that measures nitrogen oxides and ozone in the atmosphere. It offers a spatial resolution better than 100 meters at typical DC-8 research flight speeds. NOx/NOxy can be used on ground-based, airborne, and shipborne platforms, enabling it to support various atmospheric chemistry and air quality studies.

The Aerosol Mass Spectrometer (AMS) is an in situ spectrometer developed by Aerodyne Research. It employs quadrupole mass spectrometry to measure aerosol chemical composition and properties. It can detect particles ranging from 40 nm to 1 micron in size and has a time resolution of up to 10 Hz. It can be installed on aircraft, research vessels, mobile laboratories, or other ground-based platforms.

The Particle Into Liquid Sampler (PILS) is an in situ aerosol sampler manufactured by Brechtel Manufacturing Inc. PILS can be used by both ground-based and airborne platforms to gather continuous data on ambient aerosol bulk composition. The particles collected by PILS are mixed with saturated water vapor to form droplets that are analyzed by either an ion chromatograph (IC) or a total organic carbon detector (TOC). PILS can detect aerosol particles ranging from 70 nm to 2.5 μm in size and offers a time resolution of 3 minutes for airborne measurements and 15 minutes for ground-based measurements.

The NOAA Chemical Ionization Mass Spectrometer (NOAA-CIMS) is an in situ airborne spectrometer developed by NOAA. It was designed to provide high-precision measurements of reactive nitrogen and halogen species such as nitric acid, nitric oxide, and bromine chloride in the upper atmosphere. It can also provide measurements of ozone and water vapor concentrations. NOAA-CIMS has a detection limit of 30 pptv and a temporal resolution of 1 second.

The Picarro gas concentration analyzer is an in situ airborne or ground-based sensor manufactured by Picarro, Inc. It uses Wavelength-Scanned Cavity Ring Spectroscopy (WS-CRDS) to measure trace gases such as carbon dioxide, carbon monoxide, methane, and water vapor. For carbon dioxide measurements, the laser within Picarro operates at 1603 nm wavelength, while 1651 nm wavelength is used for methane and water vapor measurements. Picarro has a typical sampling time of 2.5 seconds. Depending on the model, Picarro can also provide measurements of carbon isotopes for gas concentrations.

Generic-Radiometers refer to non-specific radiometers on a platform. These are typically passive microwave radiometers that measure brightness temperature. Radiometers can be used to retrieve temperature and water vapor profiles, soil moisture content, ocean salinity, precipitation and cloud properties, and vegetation.

The Continuous Light Absorption Photometer (CLAP) is an airborne in situ photometer developed by the NOAA Global Monitoring Laboratory (GML) Aerosol Group. It uses light-diffusing filtering to measure aerosol light absorption coefficients at 468, 529, and 652 nm. It has a detection limit of 0.02 inverse megameters and a precision of 4% for hourly averages. CLAP was designed for long-term studies of the climate-forcing properties of aerosols.

Generic-Chemical Ionization Mass Spectrometry (Gen-CIMS) refers to a non-specific CIMS instrument on a platform. A CIMS is an in situ mass spectrometer that measures gas species by ionizing the molecules through chemical reactions. They provide measurements of trace gases, organic compounds, inorganic compounds, halogen species, and reactive nitrogen species.

GEOstationary Coastal and Air Pollution Events (GEO-CAPE) Airborne Simulator (GCAS) is an airborne push-broom instrument with two spectrometers. It was developed by the Radiometric Calibration and Flight Development Laboratory at Goddard Space Flight Center (GSFC) as a simulator for the GEO-CAPE mission. The first spectrometer in GCAS operates in the ultraviolet to visible (300-490 nm) range for air quality observations of nitrogen dioxide (NO2), ozone (O3), formaldehyde (HCHO), and other trace gases. The second spectrometer operates in the visible to near-infrared (480-900 nm) range to provide measurements of ocean color. GCAS has a typical spatial resolution of 250m across track and 500m along track at an altitude of 9 km, with a frame rate of 12 Hz.

The Airborne Multiangle SpectroPolariMetric Imager (AirMSPI) is a passive remote sensing, airborne pushbroom camera developed by the Jet Propulsion Laboratory (JPL) along with engineers from the University of Arizona and the University of Texas. AirMSPI operates across eight spectral bands (355, 380, 445, 470, 555, 660, 865, 935 nm) to deliver multiangle radiance and linear polarization imagery, which can be used to determine aerosol and cloud microphysical properties. AirMSPI has a spatial resolution ranging from 10 to 25 meters, depending on the scan mode, and typically captures images at a rate of 23 Hz. It was designed to be mounted on the nose of NASA’s ER-2 aircraft and has been used in several aerosol and cloud research missions.

The NPOESS Aircraft Sounder Testbed - Interferometer (NAST-I) is an airborne infrared interferometer operated and maintained by NASA Langley Research Center (LaRC). It uses Fourier transform spectroscopy to measure brightness temperature and radiance. NAST-I operates within the spectral range of 3.7-16.1 µm and has a spectral resolution of 0.25 cm-1. It features a spatial resolution of 2.6 km and a cross-track swath width of 46 km at a flight altitude of 20 km. A complete scan cycle for NAST-I takes approximately 12.2 seconds.

The Cloud Physics Lidar (CPL) is an airborne lidar system designed specifically to provide multi-wavelength measurements of cirrus clouds, sub-visual cirrus clouds, and aerosols. It measures lidar backscatter at three wavelengths: 355 nm, 532 nm, and 1064 nm. These measurements can be used to determine cloud optical depth, particle size distribution, extinction profiles, aerosol layers, and other properties. CPL has a vertical resolution of 30 m and a typical horizontal resolution of 200 m. It has a measurement sampling rate of 1 Hz.

The Enhanced MODIS Airborne Simulator (eMAS) is an airborne cross-track scanning spectrometer operated by the Airborne Sensor Facility (ASF) at NASA Ames Research Center. eMAS captures high-resolution imagery of cloud and surface features, which can be used to develop and test algorithms for MODIS satellite observations. It operates across 38 spectral channels covering wavelengths from 0.445 to 14.1 µm and has a scan rate of 6.25 Hz. eMAS offers a spatial resolution of 50 meters and a swath width of 37.25 kilometers at an altitude of 20 kilometers.

The Scanning High-resolution Interferometer Sounder (S-HIS) is an airborne cross-track scanning interferometer developed by the Space Science and Engineering Center at the University of Wisconsin-Madison. It measures emitted thermal radiation between 3.3 and 18 microns with high spectral resolution. These measurements help derive atmospheric profiles of temperature and water vapor in clear-sky conditions. S-HIS has a spatial resolution of 2 km and a swath width of 40 km at an altitude of 20 km at nadir. It operates at a sampling frequency of 0.5 seconds and has an absolute radiance accuracy of 0.2 K.

The Airborne Visible/Infrared Imaging Spectrometer - Classic (AVIRIS-C) is a passive imaging spectrometer developed at the Jet Propulsion Laboratory (JPL). It collects visible and infrared images across 224 spectral channels in the 380 to 2510 nm range. It has a horizontal resolution of 20 m and a swath width of 12 km at an altitude of 20 km. It operates at a scan rate of 12 Hz. AVIRIS-C has been replaced by AVIRIS-Next Generation (AVIRIS-NG), but it still remains in use.

Generic-Atmospheric State (Gen-AtmsState) refers to non-specific instruments on a platform used for measurements of atmospheric state parameters. These are typically in situ sensors that measure temperature, pressure, humidity, and wind speed/direction. Types of atmospheric state instruments include thermometers, hygrometers, barometers, and anemometers.

The Hyperspectral Thermal Emissions Spectrometer (HyTES) is an airborne pushbroom imaging spectrometer developed by the Jet Propulsion Laboratory (JPL). It was designed to support the Hyperspectral Infrared Imager (HyspIRI) missions and has been used in several research missions since 2012. HyTES offers high spatial and spectral resolution measurements of brightness temperature, emissivity, and land surface temperature. It operates across 256 spectral channels between 7.5 and 12 µm wavelengths and has an integration time of 30 ms. HyTES has a horizontal resolution of 7 m and a swath width of 3.6 km at a flight altitude of 4 km. HyTES was funded through NASA’s Earth Science Technology Office (ESTO) Instrument Incubator Program (IIP).

The Laser Induced Fluorescence-Nitrogen Oxide (LIF-NO) is an airborne optical sensor operated by NOAA that detects nitric oxide (NO) in the upper troposphere and lower stratosphere. It utilizes single-photon laser-induced fluorescence and employs a tunable laser at 1074-1076 nm to generate the fifth harmonic, near 215 nm, for NO detection. It has a sampling rate of 1 Hz, a detection limit of 1 pptv, and an accuracy of 9%.

The Atmospheric Vertical Observations of CO2 in the Earth’s Troposphere (AVOCET) is an airborne in situ spectrometer built by NASA’s Langley Research Center (LaRC). AVOCET uses a differential, non-dispersive infrared spectrometer to provide high-resolution measurements of carbon dioxide (CO2). It operates at the 4.26 μm CO2 absorption band and has a measurement frequency of 5 Hz. Since the early 1990s, AVOCET has been used in multiple field studies and has taken part in over 450 science flights.

The Cloud Droplet Probe (CDP) is an in situ cloud probe manufactured by Droplet Measurement Technologies. It measures the particle size distribution and concentration for cloud particles in the 2-50 μm size range. CDP detects pulses of light scattered from a laser (658 nm) to count and size individual cloud droplets. CDP has a typical measurement rate of 1 Hz and can detect concentrations of up to 2000 particles per cubic centimeter.

The NOAA Chemical Ionization Mass Spectrometer (NOAA-CIMS) is an in situ airborne spectrometer developed by NOAA. It was designed to provide high-precision measurements of reactive nitrogen and halogen species such as nitric acid, nitric oxide, and bromine chloride in the upper atmosphere. It can also provide measurements of ozone and water vapor concentrations. NOAA-CIMS has a detection limit of 30 pptv and a temporal resolution of 1 second.

The Aerosol Mass Spectrometer (AMS) is an in situ spectrometer developed by Aerodyne Research. It employs quadrupole mass spectrometry to measure aerosol chemical composition and properties. It can detect particles ranging from 40 nm to 1 micron in size and has a time resolution of up to 10 Hz. It can be installed on aircraft, research vessels, mobile laboratories, or other ground-based platforms.

Condensation Particle Counters (CPCs) are in situ sensors that measure aerosol particle concentrations. CPCs determine aerosol levels by condensing fluid onto particles, causing them to grow to sizes detectable by optical scattering. Typically, CPCs can detect particles ranging from 7 nm to 3 μm, measure concentrations up to 100,000 particles per cubic centimeter, and provide readings every second. CPCs are manufactured by TSI Incorporated and can be used on airborne, shipborne, and ground-based platforms.

The Laser Aerosol Spectrometer (LAS) is an in situ airborne spectrometer manufactured by TSI, Inc. LAS measures particle size by analyzing how particles scatter light. It operates at a 633 nm wavelength and detects particles ranging from 0.09 to 7.5 μm. LAS can deliver complete particle size distributions at a rate of 10 Hz. It is commonly used as part of aerosol instrument suites, such as NASA’s Langley Aerosol Research Group Experiment (LARGE) and NOAA’s Aerosol Microphysical Properties (AMP).

The MODIS/ASTER Airborne Simulator (MASTER) is an airborne scanning spectrometer developed at NASA Ames Research Center (ARC) in collaboration with Jet Propulsion Laboratory (JPL) to support the validation of MODIS and ASTER retrieval algorithms. MASTER is maintained and operated by the Airborne Sensor Facility (ASF) at ARC. It provides visible to shortwave infrared and thermal infrared imagery and operates across 50 spectral channels within the 0.4-13 μm wavelength range. MASTER features a pixel spatial resolution of 5 to 50 meters and a swath width of 1.87 to 37.25 km, depending on the flight altitude. Its typical scan rate is 6.25 Hz.

The Particle Soot Absorption Photometer (PSAP) is an in situ airborne photometer manufactured by Radiance Research. It applies Beer's Law to measure the change in light transmission of aerosol particles. These measurements help determine aerosol absorption and extinction. PSAP operates across three wavelengths (467, 530, and 660 nm) and has a 1-second time resolution. It is usually deployed on aircraft, but it can also be used on ships and vehicles.

Gas Chromatography/Mass Spectrometry (GC-MS) is an in situ measurement technique used to analyze volatile organic compounds (VOCs) in the atmosphere. It employs gas chromatography to separate components of an air sample, and mass spectrometry to ionize, identify, and quantify gas species. GC-MS is utilized to detect VOCs, halocarbons, hydrocarbons, and various other pollutants. It can be used for ground-based or airborne operations.

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.

Generic-Atmospheric State (Gen-AtmsState) refers to non-specific instruments on a platform used for measurements of atmospheric state parameters. These are typically in situ sensors that measure temperature, pressure, humidity, and wind speed/direction. Types of atmospheric state instruments include thermometers, hygrometers, barometers, and anemometers.

The Proton Transfer Mass Spectrometer (PTR-MS) is an in situ spectrometer used both on aircraft and ground, developed by the University of Innsbruck in Austria. It detects volatile organic compounds (VOCs) without the need for sample preparation at very low concentrations. PTR-MS employs chemical ionization mass spectrometry, enabling quick and highly sensitive VOC detection. It has a signal integration time ranging from 0.5 to 1 second.

The Georgia Institute of Technology Chemical Ionization Mass Spectrometer (GT-CIMS) is an in situ airborne spectrometer. It employs a lower-pressure flow tube reactor to detect reactive nitrogen species such as nitric acid and peroxyacetyl nitrate (PAN) in the lower atmosphere. GT-CIMS typically has a temporal resolution of 1 second and a detection limit of 10 pptv.

The Trace Organic Gas Analyzer (TOGA) is an in situ airborne analyzer that measures volatile organic compounds (VOCs) in the atmosphere. It combines fast gas chromatography and mass spectrometry to provide atmospheric mixing ratios of VOCs. It can detect a wide range of VOCs with high precision (<3%) and accuracy (20% or better), with a time resolution of 40 seconds for a 2-minute cycle.

LI-COR Gas Analyzer is an in situ gas analyzer manufactured by LI-COR. They can be deployed on aircraft, research vessels, vehicles, balloons, and ground-based platforms. They provide measurements of various trace gases such as carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and water vapor (H2O). Most models use Optical Feedback-Cavity Enhanced Absorption Spectroscopy (OF-CEAS) to collect measurements. LI-COR gas analyzers have a typical measurement rate of 1 Hz and an operating temperature range of -25 to 45 degrees Celsius.

The Scanning Mobility Particle Sizer (SMPS) is an in situ aerosol sensor that can be operated on airborne or ground-based platforms, manufactured by TSI Incorporated. SMPS uses a differential mobility analyzer (DMA) to measure the electrical mobility diameter of aerosol particles, which helps determine the size distribution. It also counts the number of aerosol particles using a condensation particle counter (CPC). It detects particles in the size range of 10-1000 nm and typically takes about 10 seconds to complete each scan.

The Open-Path Ammonia Laser Spectrometer (OPALS) is an in situ airborne spectrometer developed by Princeton University. It is a quantum cascade laser-based spectrometer that detects ammonia (NH3) at the 9.06 μm wavelength. It can measure a wide range of NH3 mixing ratios and offers improved capabilities for emission source characterization and flux measurements. OPALS has a precision of 0.15 ppbv, an accuracy of 10%, and a time resolution of 10 Hz.

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.

The Soluble Acidic Gases and Aerosols (SAGA) is an in-situ airborne sampler owned and operated by the University of New Hampshire. It uses a mist chamber and ion chromatography to collect and analyze specific aerosol species. It can provide samples of nitric acid, chloride, sulfates, nitrates, sodium, potassium, ammonium, and calcium. SAGA has a typical sampling interval of 5 to 15 minutes and a detection limit of 1 to 25 pptv, depending on the sampled species.

The Compact Airborne NO2 Experiment (CANOE) is an in situ analyzer developed at Goddard Space Flight Center (GSFC). It uses non-resonant laser-induced fluorescence (LIF) to measure nitrogen dioxide (NO2) throughout the troposphere and lower stratosphere. A 532 nm laser detects the fluorescence from NO2 molecules to determine the concentration. CANOE provides measurements at a rate of 1 Hz.

The Ultra-High Sensitivity Aerosol Spectrometer (UHSAS) is an in situ spectrometer developed by Droplet Measurement Technologies. It can be used on both airborne and ground-based platforms to measure aerosol size distribution and concentration. UHSAS determines particle size by detecting the peak light signals from aerosol particles illuminated by a 1054 nm laser. It can sample particles in the 60–1000 nm size range and operates at a sampling frequency of 10 Hz.

The Single Particle Soot Photometer (SP2) is an in situ laser-induced photometer developed by Droplet Measurement Technologies. SP2 measures the black carbon (BC) mass in individual aerosol particles, along with their optical and physical properties that contain BC. The device detects aerosol particles with diameters of 200-400 nm and can analyze up to 25,000 particles per second. It operates at a sampling rate of 1 Hz and uses a wavelength of 1.06 μm. It can be used on airborne or ground-based platforms and paired with a Humidified-Dual SP2 (HD-SP2).

The Differential Absorption Lidar (DIAL) - High Spectral Resolution Lidar (HSRL) is an airborne lidar that combines both DIAL and HSRL techniques to measure ozone and aerosols at the same time. DIAL typically operates at wavelengths of 289 nm and 300 nm to profile ozone. The HSRL modification adds a three-wavelength (355 nm, 532 nm, 1064 nm) narrowband laser to the DIAL system, enabling measurements of aerosol backscatter, extinction, depolarization, and other aerosol properties. For ozone measurements, DIAL-HSRL generally has a vertical resolution of 330 m and a temporal resolution of 90 seconds. For aerosol measurements, it features a vertical resolution of 30 m and a temporal resolution of 10 seconds.

The Whole Air Sampler (WAS) is an airborne in-situ instrument that collects air samples for analyzing trace gases, such as nonmethane hydrocarbons (NMHCs), halocarbons, alkyl nitrates, and various sulfur compounds found in the troposphere. Air samples collected by the WAS are then analyzed using gas chromatography and mass spectrometry to identify the gases present. The WAS collects samples every minute, allowing scientists to get a clear picture of the environment's chemical composition as research aircraft pass through.

The Condensation Nuclei Counter (CNC) is an in situ optical sensor produced by Droplet Measurement Technologies. It detects cloud condensation nuclei (CCN) by supersaturating the sampled air, allowing CCN particles to become detectable. The particles are then measured with an optical particle counter (OPC). CNC can detect particles from 0.75 to 10 μm in diameter and operates at a sampling rate of 1 Hz. It is suitable for both airborne and ground-based operations.

The Forward Looking InfraRed (FLIR) imaging camera is an airborne infrared camera that measures radiance and provides thermal images. It is used to detect thermal properties of various land surfaces such as vegetation, water, snow, and soil. FLIR operates within the 8-12 μm spectral range. It has a field of view of 110 meters by 30 meters at an altitude of 600 meters above ground level.

The Compact Atmospheric Multispecies Spectrometer (CAMS) is an in situ airborne spectrometer developed by the University of Colorado. CAMS uses mid-IR (3.53 μm) absorption spectroscopy to measure formaldehyde and ethane in the atmosphere. It employs difference-frequency generation (DFG) to produce mid-IR light by mixing two near-IR (1562 and 1083 nm) laser sources. CAMS provides high-precision measurements at a sampling rate of 1 Hz.

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 detect water vapor in the atmosphere. DLH operates in the near-infrared range at about 1.4 μm and has a measurement frequency of 100 Hz. It can deliver precise measurements of water vapor even when flying through clouds.

The In Situ Airborne Formaldehyde (ISAF) is an airborne optical sensor developed by NASA's Goddard Space Flight Center (GSFC). ISAF uses laser-induced fluorescence (LIF) to measure formaldehyde throughout the troposphere and lower stratosphere. It operates at a wavelength of 353 nm and has a sampling frequency of 1 Hz. ISAF can detect formaldehyde concentrations from 10 pptv to hundreds of ppbv with an accuracy of 10%.

The Rapid OZone Experiment (ROZE) is an airborne in situ instrument that measures ozone levels in the troposphere and lower stratosphere. It employs the incoherent broadband cavity-enhanced absorption spectroscopy (IBBCEAS) technique to determine ozone concentrations in the sampled volume. ROZE utilizes a light-emitting diode (LED) in the ultraviolet (UV) spectrum at 265 nm. ROZE operates with a measurement sampling rate of 10 Hz and an accuracy of 6.2%.

NOx/NOxy is an in situ chemiluminescence instrument that measures nitrogen oxides and ozone in the atmosphere. It offers a spatial resolution better than 100 meters at typical DC-8 research flight speeds. NOx/NOxy can be used on ground-based, airborne, and shipborne platforms, enabling it to support various atmospheric chemistry and air quality studies.

The High Resolution Aerosol Mass Spectrometer (HR-AMS) is an in situ airborne mass spectrometer designed to detect aerosol composition and chemistry. It is a modified version of the Aerodyne Aerosol Mass Spectrometer developed by the University of Colorado. It measures the mass concentrations of aerosol particles ranging from 50 nm to 1 μm. HR-AMS detects aerosol composition through impaction at 600 °C, followed by electron ionization and mass spectral analysis. It has a measurement sampling rate of 1 Hz.

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

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.

The Aerosol Sampling for Transmission Electron Microscopy (AS-TEM) is an airborne aerosol sampler. It collects and filters aerosol samples using an impactor, which are then analyzed with transmission electron microscopy (TEM) to determine the particles' size, shape, composition, and mixing state. It can sample fine (100-700 nm) and coarse particles (>700 nm). AS-TEM can also be used for ground-based sampling.

The Cloud, Aerosol, and Refractive Index Experiment (CARE) is an airborne in situ instrument suite operated by the University of Vienna. It consists of three instruments: an Optical Particle AnaLyzer (OPAL), a Cloud, Aerosol, and Precipitation Spectrometer (CAPS), and a Precipitation Imaging Probe (PIP). CARE provides measurements of particle size distributions for aerosol and cloud particles in the 0.5 μm to 6.2 mm size range at a sampling frequency of 1 Hz. It also provides information about particle shape and cloud phase and allows for refractive index retrievals of single particles in the 0.5 to 2 μm size range.

The Cloud Particle Spectrometer with Polarized Detection (CPSPD) is an in situ airborne spectrometer manufactured by Droplet Measurement Technologies. It measures forward and backward scattered light of cloud and aerosol particles at 658 nm. These measurements can be used to derive particle properties such as particle size distribution, number concentration, effective diameter, and liquid water content. CPSPD measures particles in the 0.65 to 30 μm size range and measures 20,000 particles per second. It has a selectable sampling frequency of 0.04 to 20 seconds.

The Los Gatos Research (LGR) Greenhouse Gas Analyzer (GGA) is a portable analyzer suitable for in situ measurements, either airborne or ground-based. It utilizes off-axis integrated cavity output spectroscopy (OA-ICOS) technology to simultaneously measure methane (CH4), carbon dioxide (CO2), and water vapor (H2O). It can detect CH4 levels up to 100 ppm, CO2 up to 20,000 ppm, and H2O up to 30,000 ppm. The device offers a selectable measurement rate ranging from 0.01 to 1 Hz, with some models featuring a fast flow option capable of rates up to 10 Hz.

Differential Optical Absorption Spectroscopy (DOAS) is a passive spectrometer technique used to measure trace gas concentrations. It detects trace gases by measuring specific, narrow-band absorptions in the ultraviolet and visible light spectrum. DOAS is typically used to detect ozone (O3), nitrogen dioxide (NO2), formaldehyde (CH2O), and sulfur dioxide (SO2). It is suitable for both airborne and ground-based applications.

The Airborne Cavity Enhanced Spectrometer (ACES) is a two-channel spectrometer designed for aircraft measurements of glyoxal (CHOCHO), methylglyoxal (CH3COCHO), nitrous acid (HONO), nitrogen dioxide (NO2), and water vapor (H2O). ACES provides high-sensitivity measurements of trace gases and aerosols by passing light through an optical cavity equipped with a grating spectrometer and a charge-coupled device. It operates across two wavelength ranges (361-389 nm and 438-468 nm) and offers high precision and rapid measurement frequency.

The Aerosol Optical Properties (AOP) is an in situ airborne suite consisting of a Cavity Ringdown Spectrometer (CRDS), a Photoacoustic Absorption Spectrometer (PAS), and an Ultra-High Sensitivity Aerosol Size Spectrometer (UHSAS). It provides multi-wavelength measurements of aerosol extinction, absorption, and other properties. CRDS measures aerosol extinction at 405, 532, and 662 nm wavelengths and has an accuracy of less than 2%. PAS measures absorption at 405, 532, and 660 nm wavelengths and has a sampling rate of 1 Hz. UHSAS measures the size distribution of aerosol particles within the size range of 0.008 to 1 μm. The measurements from the combined AOP instrument package allow for the calculation of radiative forcing and atmospheric heating rates.

The Charged-couple device (CCD) Actinic Flux Spectroradiometer (CAFS) is an in situ airborne spectroradiometer developed by the Atmospheric Radiation Investigations and Measurements (ARIM) laboratory at NCAR. CAFS measures spectrally resolved ultraviolet and visible actinic flux between 280-650 nm. These measurements can be used to derive the photolysis frequencies for several chemical compounds such as ozone, nitrogen dioxide, formaldehyde, and nitrate. CAFS has a temporal resolution of 1 Hz and a wavelength resolution of about 1.8 nm at 297 nm.

The CalTech Chemical Ionization Mass Spectrometer (CIT-CIMS) is an in situ airborne single-mass spectrometer. CIT-CIMS uses CF3O-ion chemistry and compact time-of-flight and triple quadrupole spectrometers to measure specific atmospheric trace gases such as nitric acid, hydrogen peroxide, and sulfur dioxide. It was designed with rapid scan capabilities, enabling it to operate at a high temporal resolution (10 Hz) and detect a wide range of masses. CIT-CIMS is typically used for airborne observations but can also be employed for ground-based measurements.

The Differential Absorption Carbon monOxide Measurements (DACOM) is an airborne in situ spectrometer system. It uses the differential absorption technique and an infrared tunable diode laser (TDL) to collect measurements of nitrous oxide (N2O), carbon dioxide (CO2), carbon monoxide (CO), and methane (CH4) in the atmosphere. DACOM operates across the 4.7, 4.5, and 3.3 μm wavelengths to access the absorption lines for CO, N2O, and CH4. It has a measurement frequency of 5 Hz and a precision of about 1 ppbv.

The Langley Aerosol Research Group Experiment (LARGE) is an in situ airborne instrument suite that measures aerosol and cloud microphysical and optical properties, such as size distribution, number concentration, and scattering and absorption coefficients. LARGE includes several instruments, such as the Ultra-High Sensitivity Aerosol Spectrometer (UHSAS), Particle-Into-Liquid Sampler (PILS), Particle Soot Absorption Photometer (PSAP), Cloud and Aerosol Spectrometer (CAS), Cloud Imaging Probe (CIP), and additional cloud and aerosol sensors. The LARGE instruments operate over the 450-700 nm wavelength range, detect particles ranging from 0.003 to 20 μm, and measure at a frequency of 1 Hz. It is primarily used for airborne measurements but can also be deployed on ground-based platforms like vehicles.

The Laser Induced Fluorescence-Sulfur Dioxide (LIF-SO2) is an airborne optical sensor operated by NOAA to measure SO2 in the upper troposphere and lower stratosphere. It is based on the single-photon laser-induced fluorescence technique and uses a tunable diode laser at 1084.5 nm to excite SO2 at 216.9 nm. It detects SO2 at a sampling rate of 1 Hz, with a detection limit of 5 pptv and an accuracy of 10%.

The Optical Particle Counter (OPC) is an optical device used to measure aerosol particle size and concentration. It determines particle size and concentration by detecting the intensity of scattered light. Most OPCs operate within the visible to near-infrared wavelengths (500-1100 nm) and have a time resolution of 1 second. They are typically used to measure particles larger than 0.5 μm in diameter. OPCs can be used for both airborne and ground-based applications.

The Printed Optical Particle Spectrometer (POPS) is an in situ spectrometer that measures particle size and concentration. POPS can be mounted on UAVs or balloons to gather vertical aerosol particle profiles. Operating at a typical wavelength of 405 nm, POPS provides measurements roughly every second and detects particles from 140 nm to 3000 nm in size.

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 Forward Looking InfraRed (FLIR) imaging camera is an airborne infrared camera that measures radiance and provides thermal images. It is used to detect thermal properties of various land surfaces such as vegetation, water, snow, and soil. FLIR operates within the 8-12 μm spectral range. It has a field of view of 110 meters by 30 meters at an altitude of 600 meters above ground level.

Generic-Atmospheric State (Gen-AtmsState) refers to non-specific instruments on a platform used for measurements of atmospheric state parameters. These are typically in situ sensors that measure temperature, pressure, humidity, and wind speed/direction. Types of atmospheric state instruments include thermometers, hygrometers, barometers, and anemometers.

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.

The 2B Technologies Ozone (O3) Monitor is an in-situ dual-beam ozone monitor suitable for airborne and ground-based use. It measures O3 concentration through dual-beam ultraviolet (UV) absorption at 254 nm. The device has a detection range of 0 to 20 ppm, a resolution of 0.1 ppb, and provides measurements every 2 seconds. Its operating temperature range is 0 to 50 degrees Celsius, with an altitude range of approximately 0 to 13.5 km.

The Aerosol Mass Spectrometer (AMS) is an in situ spectrometer developed by Aerodyne Research. It employs quadrupole mass spectrometry to measure aerosol chemical composition and properties. It can detect particles ranging from 40 nm to 1 micron in size and has a time resolution of up to 10 Hz. It can be installed on aircraft, research vessels, mobile laboratories, or other ground-based platforms.

Condensation Particle Counters (CPCs) are in situ sensors that measure aerosol particle concentrations. CPCs determine aerosol levels by condensing fluid onto particles, causing them to grow to sizes detectable by optical scattering. Typically, CPCs can detect particles ranging from 7 nm to 3 μm, measure concentrations up to 100,000 particles per cubic centimeter, and provide readings every second. CPCs are manufactured by TSI Incorporated and can be used on airborne, shipborne, and ground-based platforms.

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.

Generic-Atmospheric State (Gen-AtmsState) refers to non-specific instruments on a platform used for measurements of atmospheric state parameters. These are typically in situ sensors that measure temperature, pressure, humidity, and wind speed/direction. Types of atmospheric state instruments include thermometers, hygrometers, barometers, and anemometers.

The Proton Transfer Mass Spectrometer (PTR-MS) is an in situ spectrometer used both on aircraft and ground, developed by the University of Innsbruck in Austria. It detects volatile organic compounds (VOCs) without the need for sample preparation at very low concentrations. PTR-MS employs chemical ionization mass spectrometry, enabling quick and highly sensitive VOC detection. It has a signal integration time ranging from 0.5 to 1 second.

Generic-Radiometers refer to non-specific radiometers on a platform. These are typically passive microwave radiometers that measure brightness temperature. Radiometers can be used to retrieve temperature and water vapor profiles, soil moisture content, ocean salinity, precipitation and cloud properties, and vegetation.

LI-COR Gas Analyzer is an in situ gas analyzer manufactured by LI-COR. They can be deployed on aircraft, research vessels, vehicles, balloons, and ground-based platforms. They provide measurements of various trace gases such as carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and water vapor (H2O). Most models use Optical Feedback-Cavity Enhanced Absorption Spectroscopy (OF-CEAS) to collect measurements. LI-COR gas analyzers have a typical measurement rate of 1 Hz and an operating temperature range of -25 to 45 degrees Celsius.

The Scanning Mobility Particle Sizer (SMPS) is an in situ aerosol sensor that can be operated on airborne or ground-based platforms, manufactured by TSI Incorporated. SMPS uses a differential mobility analyzer (DMA) to measure the electrical mobility diameter of aerosol particles, which helps determine the size distribution. It also counts the number of aerosol particles using a condensation particle counter (CPC). It detects particles in the size range of 10-1000 nm and typically takes about 10 seconds to complete each scan.

The Tunable Infrared Laser Direct Absorption Spectrometer (TILDAS) is an in situ spectrometer developed by Aerodyne Research. It measures gas concentrations by determining how much light the species absorbs at a specific wavelength. TILDAS is used to detect various trace gases, including methane, nitrous oxide, nitrogen dioxide, carbon monoxide, carbon dioxide, formaldehyde, and ammonia. The laser operates within the mid-infrared spectrum and is tuned to a specific wavelength based on the target species. It provides measurements at a data rate of up to 10 Hz. TILDAS can be deployed on aircraft, ships, trucks, and other ground-based platforms.

The Multi-Angle Absorption Photometer (MAAP) is an in situ aerosol optical sensor developed by Thermo Scientific. It provides continuous measurements of black carbon concentrations and aerosol light absorption properties. It has multiple detectors that measure transmitted and scattered light simultaneously at scattering angles of 130 and 165 degrees. MAAP operates at a wavelength of 670 nm and has a typical time resolution of 2 minutes. It is part of the Langlely Aerosol Research Group Experiment (LARGE) instrument suite and can be used for ground-based and airborne operations.

The Picarro gas concentration analyzer is an in situ airborne or ground-based sensor manufactured by Picarro, Inc. It uses Wavelength-Scanned Cavity Ring Spectroscopy (WS-CRDS) to measure trace gases such as carbon dioxide, carbon monoxide, methane, and water vapor. For carbon dioxide measurements, the laser within Picarro operates at 1603 nm wavelength, while 1651 nm wavelength is used for methane and water vapor measurements. Picarro has a typical sampling time of 2.5 seconds. Depending on the model, Picarro can also provide measurements of carbon isotopes for gas concentrations.

The Aethalometer is an in situ aerosol measuring device made by Magee Scientific. It can be used on both airborne and ground-based platforms. It collects aerosols through a filter tape and gauges the attenuation of transmitted light to assess black carbon particle levels. The Aethalometer works across seven optical wavelengths (370, 470, 520, 590, 660, 880, and 950 nm) and delivers data at a rate of 1 Hz. It has a measurement range of 0-500 μg per cubic meter and a resolution of 0.1 μg per cubic meter.

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.

The Soluble Acidic Gases and Aerosols (SAGA) is an in-situ airborne sampler owned and operated by the University of New Hampshire. It uses a mist chamber and ion chromatography to collect and analyze specific aerosol species. It can provide samples of nitric acid, chloride, sulfates, nitrates, sodium, potassium, ammonium, and calcium. SAGA has a typical sampling interval of 5 to 15 minutes and a detection limit of 1 to 25 pptv, depending on the sampled species.

The Ultra-High Sensitivity Aerosol Spectrometer (UHSAS) is an in situ spectrometer developed by Droplet Measurement Technologies. It can be used on both airborne and ground-based platforms to measure aerosol size distribution and concentration. UHSAS determines particle size by detecting the peak light signals from aerosol particles illuminated by a 1054 nm laser. It can sample particles in the 60–1000 nm size range and operates at a sampling frequency of 10 Hz.

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.

The Single Particle Soot Photometer (SP2) is an in situ laser-induced photometer developed by Droplet Measurement Technologies. SP2 measures the black carbon (BC) mass in individual aerosol particles, along with their optical and physical properties that contain BC. The device detects aerosol particles with diameters of 200-400 nm and can analyze up to 25,000 particles per second. It operates at a sampling rate of 1 Hz and uses a wavelength of 1.06 μm. It can be used on airborne or ground-based platforms and paired with a Humidified-Dual SP2 (HD-SP2).

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.

The Aerodynamic Particle Sizer (APS) is an in situ spectrometer manufactured by TSI Instruments. APS measures aerodynamic particles in the 0.5-20 μm size range. It also measures the light-scattering intensity of the particles in the 0.37-20 μm optical size range. APS provides particle size distributions for 52 channels at a typical sampling time of 1 second. It uses a laser diode operating at 655 nm and has a size resolution of 0.02 μm at 1 μm. APS can be deployed on aircraft, ships, or ground-based platforms.

NOx/NOxy is an in situ chemiluminescence instrument that measures nitrogen oxides and ozone in the atmosphere. It offers a spatial resolution better than 100 meters at typical DC-8 research flight speeds. NOx/NOxy can be used on ground-based, airborne, and shipborne platforms, enabling it to support various atmospheric chemistry and air quality studies.

The High Resolution Aerosol Mass Spectrometer (HR-AMS) is an in situ airborne mass spectrometer designed to detect aerosol composition and chemistry. It is a modified version of the Aerodyne Aerosol Mass Spectrometer developed by the University of Colorado. It measures the mass concentrations of aerosol particles ranging from 50 nm to 1 μm. HR-AMS detects aerosol composition through impaction at 600 °C, followed by electron ionization and mass spectral analysis. It has a measurement sampling rate of 1 Hz.

TSI Particle Probes are in situ particle counters and detectors manufactured by TSI Incorporated. They are used to detect aerosol particles and determine concentration and particle counts. TSI Particle Probes are typically combined with particle sizers, which can measure size distribution. TSI Particle Probes can be deployed on aircraft, research vessels, and ground-based platforms.

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.

The Los Gatos Research (LGR) Greenhouse Gas Analyzer (GGA) is a portable analyzer suitable for in situ measurements, either airborne or ground-based. It utilizes off-axis integrated cavity output spectroscopy (OA-ICOS) technology to simultaneously measure methane (CH4), carbon dioxide (CO2), and water vapor (H2O). It can detect CH4 levels up to 100 ppm, CO2 up to 20,000 ppm, and H2O up to 30,000 ppm. The device offers a selectable measurement rate ranging from 0.01 to 1 Hz, with some models featuring a fast flow option capable of rates up to 10 Hz.

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.

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 Langley Aerosol Research Group Experiment (LARGE) is an in situ airborne instrument suite that measures aerosol and cloud microphysical and optical properties, such as size distribution, number concentration, and scattering and absorption coefficients. LARGE includes several instruments, such as the Ultra-High Sensitivity Aerosol Spectrometer (UHSAS), Particle-Into-Liquid Sampler (PILS), Particle Soot Absorption Photometer (PSAP), Cloud and Aerosol Spectrometer (CAS), Cloud Imaging Probe (CIP), and additional cloud and aerosol sensors. The LARGE instruments operate over the 450-700 nm wavelength range, detect particles ranging from 0.003 to 20 μm, and measure at a frequency of 1 Hz. It is primarily used for airborne measurements but can also be deployed on ground-based platforms like vehicles.

The AErosol RObotic NETwork (AERONET) is a federated network of ground-based remote sensing aerosol sensors established by NASA and the PHOtométrie pour le Traitement Opérationnel de Normalisation Satellitaire (PHOTONS) in 1993. Each AERONET site includes a CIMEL Electronique sunphotometer that measures sun irradiance and sky radiances. These measurements are used to determine aerosol properties such as aerosol optical depth and extinction. The sunphotometers operate at nine wavelengths (340, 380, 440, 500, 675, 870, 937, 1020, and 1640 nm) and provide aerosol data approximately every 15 minutes. AERONET sites are distributed worldwide, enabling mapping of about 90% of the Earth’s surface.