The Asian Summer Monsoon Chemical and Climate Impact Project (ACCLIP) was a joint effort between NASA and NCAR that focused on studying the Asian Summer Monsoon (ASM) and how gas and aerosol emissions influence global climate during the ASM. ACCLIP included one deployment during the boreal summer of 2022, with flights based out of South Korea. A series of test flights took place in the summer of 2021 at Ellington Air Force Base (AFB) in Houston, TX. NASA's WB-57 and NCAR's G-V aircraft were equipped with remote sensing and in situ instruments to measure cloud and aerosol properties. ACCLIP was funded through NASA's Upper Atmosphere Research Program.
The Microwave Temperature Profiler (MTP) is an airborne microwave radiometer developed by the Jet Propulsion Laboratory and later modified by NCAR. It measures brightness temperature from oxygen molecules at 56.363 GHz, 57.612 GHz, and 58.363 GHz. These measurements are converted into air temperature through a statistical retrieval process. It samples across 10 viewing angles and has a vertical resolution of 150 m near the aircraft. MTP provides profiles every 17 seconds with about 4 km of horizontal spacing.
Earth Science > Spectral/engineering > Microwave > Brightness Temperature
The European Research Council (ERC) Instrument for Chemical composition of Aerosols (ERICA) is an in situ airborne aerosol mass spectrometer (AMS). It combines two techniques to measure aerosol chemical composition: laser desorption ionization and thermal desorption with subsequent electron impact ionization techniques. The sampled aerosol particles are first sized through optical detection and then are vaporized and ionized by a 266 nm ultraviolet laser to determine the chemical composition. ERICA can detect particles within the 120 nm to 3.5 μm size range and has a data frequency of 0.1 Hz.
Earth Science > Atmosphere > Aerosols > Chemical Composition
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.
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.
Earth Science > Atmosphere > Atmospheric Water Vapor
Earth Science > Atmosphere > Atmospheric Pressure
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Humidity
Earth Science > Atmosphere > Atmospheric Temperature > Surface Temperature > Air Temperature
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 HIAPER Airborne Radiation Package (HARP) is an in situ airborne radiometer developed by NCAR, the University of Colorado, the Leibniz-Institute for Tropospheric Research, Metcon, Inc., and enviscope GmbH. The instrument measures actinic flux and spectral irradiance. HARP operates in the 280-680 nm wavelength range for actinic flux and in the 260-2400 nm range for irradiance. It typically samples data at a frequency of 1 Hz.
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.
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 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 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 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 Nucleation-mode Aerosol Size Spectrometer (NMASS) is an airborne, in situ spectrometer used to measure particle size distribution and cloud condensation nuclei (CCN). NMASS includes five parallel condensation nucleus counters (CNCs) that sample particles within the 3 to 60 nm diameter range. It can be mounted on various types of aircraft and is ideal for sampling cirrus clouds in the upper atmosphere. NMASS delivers rapid measurements with a temporal resolution of 10 Hz.
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.
Earth Science > Atmosphere > Air Quality > Nitrogen Oxides
The Vertical Cavity Surface Emitting Laser (VCSEL) Hygrometer is an airborne hygrometer that measures water vapor concentration in the troposphere and lower stratosphere. It is an open-path, laser-based hygrometer that operates near the 1854 nm wavelength. The VCSEL hygrometer provides real-time water vapor concentration measurements at a sampling rate of 25 Hz. At this rate, the hygrometer has a spatial resolution of approximately 10 meters when the Gulfstream-V aircraft is at maximum speed.
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Profiles > Water Vapor Concentration Profiles
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Humidity
Earth Science > Atmosphere > Atmospheric Water Vapor
The 2D-Stereo Particle Probe (2D-S) is an in situ airborne optical imaging device developed by SPEC Inc. It uses two diode laser beams to create stereo images of cloud particles via linear array shadowing. These images allow for the determination of cloud particle size distribution, particle number concentration, and ice or liquid water content. 2D-S has a resolution of 10 µm and can measure hydrometeors ranging from 25 to 1280 µm.
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-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 Aircraft-Integrated Meteorological Measurement System (AIMMS) is an in situ airborne sensor developed by Aventech Research, Inc. It measures the aircraft's position, altitude, temperature, relative humidity, static pressure, and three-dimensional wind vector. The system includes an Inertial Measurement Unit (IMU), Global Positioning System (GPS), Air Data Probe (ADP), and a central processing module (CPM) for processing the GPS data. AIMMS provides data at a rate of up to 20 Hz and can operate in temperatures ranging from -20 to 50 degrees Celsius.
Ozonesondes are in situ balloon-borne instruments used to measure ozone concentration profiles. An ozonesonde consists of an electrochemical ozone sensor connected with a meteorological radiosonde to collect ozone, temperature, pressure, and humidity measurements as it ascends through the atmosphere. It provides ozone profile measurements at a resolution of 100 to 150 m. Ozonesondes have a typical measurement rate of 0.1 Hz and can collect profiles up to around 35 km.
Earth Science > Atmosphere > Atmospheric Water Vapor
Earth Science > Atmosphere > Atmospheric Pressure
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Profiles
Earth Science > Atmosphere > Atmospheric Temperature > Upper Air Temperature > Vertical Profiles
Earth Science > Atmosphere > Atmospheric Temperature > Upper Air Temperature
Earth Science > Atmosphere > Atmospheric Temperature
Radiosondes are a balloon-borne instrument package used to collect profile measurements of pressure, temperature, humidity, and winds. These sensors are connected to a radio transmitter that sends the measurements to a ground receiver typically operating in the 400-406 MHz range. They typically provide measurements at 1-6 seconds, depending on the type and manufacturer of the radiosonde. Radiosondes are used for weather forecasting, ground truth satellite data, atmospheric research, and input for weather prediction models.
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Profiles
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 Airborne Carbonic Oxides and Sulfide Spectrometer (ACOS) is an in situ airborne spectrometer operated by NOAA. It is a modified Los Gatos Research (LGR) Off-Axis Integrated Cavity Output Spectrometer (OA-ICOS) used to measure carbonyl sulfide (OCS), carbon dioxide (CO2), carbon monoxide (CO), and atmospheric water vapor. ACOS provides these measurements simultaneously at a typical measurement rate of 1 Hz.
The Carbon Oxide Laser Detector 2 (COLD2) is an in situ airborne quantum cascade laser spectrometer. It measures carbon monoxide (CO) at 4.7 microns in the upper troposphere and lower stratosphere. It also provides measurements of nitrous oxide (N2O). COLD2 has a measurement frequency of 1 Hz and a sensitivity of around 2 ppbv. COLD2 can also be configured to operate on balloons.
The Cloud Particle Imager (CPI) is an airborne imager developed by SPEC Inc. CPI captures high-resolution (2.3 μm pixel size) images of cloud particles that pass through its sampling volume. It uses a charge-coupled device (CCD) camera operating at 810 nm to record images and can capture up to 74 frames per second with a refresh rate of 40 Hz. The images from CPI can be used to determine microphysical properties such as particle size and shape.
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.
Roscoe is an airborne aerosol and cloud lidar system. It is a more compact version of the Cloud Physics Lidar (CPL) developed by Goddard Space Flight Center (GSFC). It was designed to observe both upwards and downwards from the aircraft to collect profile measurements of attenuated backscatter and aerosol/cloud optical properties. Roscoe operates at 355 nm and 1064 nm wavelengths and has a resolution of 200 m. It has a temporal resolution of 1 second.
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 Particle Analysis by Laser Mass Spectrometry (PALMS) is a laser ionization mass spectrometer operated by NOAA. PALMS provides in situ measurements of aerosol particles and their chemical composition by using a UV laser pulse (193 nm) to generate ions. These ions are then analyzed with a time-of-flight mass spectrometer to produce the mass spectrum of each particle, which can be used to classify individual aerosol particles. PALMS has an aerosol size range of 0.2 to 3 microns and typically collects data at about 1 to 10 Hz. It can be used for either airborne or laboratory aerosol measurements.
Earth Science > Atmosphere > Aerosols > Chemical Composition
Earth Science > Atmosphere > Aerosols
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).
Broadband Radiometers (BBR) are modified versions of the Kipp & Zonen CM-22 pyranometers and CG-4 pyrgeometers. They have been adapted for use on airborne platforms through different instrument housing and signal amplification. BBR measures solar irradiance in the 0.2-3.6 μm wavelength range and infrared (IR) irradiance in the 4.5-42 μm range. These measurements can be used to derive net irradiance, radiative forcing, absorption, and albedo. It has a typical sampling rate of 1 Hz and a hemispheric field of view.
Earth Science > Atmosphere > Atmospheric Radiation > Solar Irradiance
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 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 a wavelength of 254 nm, enabling it to calculate ozone number density due to the precise ozone absorption cross section at that wavelength. It has a sampling rate of 2 Hz and a horizontal resolution of 100 to 200 meters during typical research flights.
Earth Science > Atmosphere > Air Quality > Tropospheric Ozone
The Nucleation-mode Aerosol Size Spectrometer (NMASS) is an airborne, in situ spectrometer used to measure particle size distribution and cloud condensation nuclei (CCN). NMASS includes five parallel condensation nucleus counters (CNCs) that sample particles within the 3 to 60 nm diameter range. It can be mounted on various types of aircraft and is ideal for sampling cirrus clouds in the upper atmosphere. NMASS delivers rapid measurements with a temporal resolution of 10 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.
Earth Science > Atmosphere > Atmospheric Water Vapor
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Water Vapor
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Humidity > Relative Humidity
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Humidity
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 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.
The Fast Cloud Droplet Probe (FCDP) is an in situ airborne cloud probe manufactured by SPEC Inc. The FCDP measures the concentration and size of cloud droplets by detecting light scattered by particles. It detects particles with diameters ranging from 1.5 to 50 microns and typically records measurements at 1 Hz.
The Particles in the Upper Troposphere/Lower Stratosphere (PUTLS) is an in situ airborne instrument suite. It consists of three individual instruments: a Nucleation Mode Aerosol Size Spectrometer (NMASS), an Ultra-High Sensitivity Aerosol Spectrometer (UHSAS), and a Portable Optical Particle Spectrometer (POPS). It is used to measure aerosol number concentration and size distribution in the upper troposphere and lower stratosphere. PUTLS can measure particles in the 4 to 3000 nm diameter size range and has a measurement frequency of 1 Hz.
The Chicago Water Isotope Spectrometer (ChiWIS) is an in situ integrated cavity output spectrometer (ICOS) operated by the University of Chicago. It measures water vapor (H2O) and semi-heavy water (HDO) in the dry upper troposphere and lower stratosphere (UTLS). It operates at the 2.647 μm wavelength and has an effective path length of 7.5 km. ChiWIS has a time resolution of 5 seconds, resulting in a spatial resolution of 1 km for aircraft speeds of 200 meters per second. ChiWIS has a precision of 3.6 ppbv for H2O and 82 pptv for HDO.
Earth Science > Atmosphere > Atmospheric Water Vapor
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Water Vapor
The Carbon monOxide Measurement from Ames (COMA) is an in situ airborne spectrometer that measures carbon monoxide (CO) and nitrous oxide (N2O). It is an Off-Axis Integrated Cavity Output Spectrometer (OA-ICOS) manufactured by Los Gatos Research that has been converted for high-altitude (18 km) observations of CO and N2O. It has an uncertainty of 4.1 to 5.9 ppb for CO measurements and 2.7 ppb for N2O measurements. COMA has a typical measurement rate of 1 Hz.
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.
Earth Science > Human Dimensions > Public Health > Environmental Health Factors > Particulate Matter Concentrations
The 2D-Stereo Particle Probe (2D-S) is an in situ airborne optical imaging device developed by SPEC Inc. It uses two diode laser beams to create stereo images of cloud particles via linear array shadowing. These images allow for the determination of cloud particle size distribution, particle number concentration, and ice or liquid water content. 2D-S has a resolution of 10 µm and can measure hydrometeors ranging from 25 to 1280 µm.
The Aerosol Microphysical Properties (AMP) is an in situ airborne instrument suite operated by NOAA. It includes instruments such as the Nucleation-Mode Aerosol Size Spectrometer (NMASS), Ultra-High Sensitivity Aerosol Spectrometer (UHSAS), Laser Aerosol Spectrometer (LAS), and Coarse-Mode Aerosol Size Spectrometer (CMASS). AMP provides measurements of aerosol particle size distribution, as well as particle number, size, and volume concentration. It can measure aerosols within a size range of 3 to 40,000 nm and offers measurements at 1 Hz resolution.
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%.
