The Aerosol Cloud meTeorology Interactions oVer the western ATlantic Experiment (ACTIVATE) was a NASA-led, multi-year campaign that studied marine boundary layer cloud systems and aerosols. ACTIVATE consisted of six deployments from 2020 to 2022 over the Western North Atlantic Ocean. NASA's B-200 and Falcon aircraft were equipped with remote and in situ sensors to collect measurements of marine cloud and aerosol properties within the boundary layer. ACTIVATE was part of the Earth Venture Suborbital-3 (EVS-3) program.
The Research Scanning Polarimeter (RSP) is an airborne, passive polarimeter developed by SpecTIR Corporation. It measures total radiance and linear polarization across nine spectral bands in the visible and infrared wavelengths (410-2250 nm). These measurements can be used to determine aerosol and cloud properties. RSP has a time resolution of 0.8 seconds, a field of view of 14 mrad, and a horizontal resolution of approximately 100 meters at an altitude of 5 km.
The High Spectral Resolution Lidar 2 (HSRL-2) is an airborne lidar developed by NASA's Langley Research Center. HSRL-2 measures aerosol backscatter at 355, 532, and 1064 nm wavelengths and aerosol extinction at 355 and 532 nm wavelengths. It has a horizontal resolution of 1-2 km and a vertical resolution of 15 m, with measurements taken approximately every 0.5 seconds. It replaced the original High Spectral Resolution Lidar (HSRL).
Earth Science > Spectral/engineering > Lidar > Lidar Depolarization Ratio
Dropsondes, also known as dropwindsondes, are in situ instruments designed to be released from aircraft. They are equipped with Global Positioning System (GPS) receivers and sensors to collect profile measurements of pressure, temperature, humidity, wind speed, and wind direction. Dropsondes are important during field investigations because they enable researchers to collect vertical profiles in remote locations and during severe weather conditions. Typically, dropsondes have a vertical resolution of 5 meters and provide wind speed and direction measurements every 0.25 seconds, while temperature, pressure, and humidity are recorded every 0.5 seconds.
Rosemount Temperature Probes are in situ airborne temperature sensors manufactured by Rosemount, Inc. They provide atmospheric temperature measurements and are typically used to collect flight-level meteorological observations. Rosemount Temperature Probes consist of temperature transmitters, thermocouple sensors, resistance temperature detectors, and other temperature sensors.
Earth Science > Atmosphere > Atmospheric Temperature > Upper Air Temperature
Earth Science > Atmosphere > Atmospheric Temperature
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 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.
Earth Science > Atmosphere > Aerosols > Chemical Composition
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 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.
Earth Science > Atmosphere > Aerosols > Chemical Composition
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.
The Turbulent Air Motion Measurement System (TAMMS) is an in situ airborne sensor used to gather aircraft navigation information. TAMMS consists of several subsystems, including pressure transducers and temperature sensors, an aircraft inertial navigation system, a central data acquisition system, and water vapor and other gas sensors. It provides measurements of aircraft position, flight level winds, temperature, pressure, and water vapor. TAMMS has a typical sampling frequency of less than 1 second and a spatial resolution of 5 meters.
Earth Science > Atmosphere > Atmospheric Temperature
Earth Science > Atmosphere > Atmospheric Winds
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.
Earth Science > Atmosphere > Aerosols
Earth Science > Atmosphere > Aerosols > Chemical Composition
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 Axial Cycle Cloud-water Collector (AC3) is an in situ airborne cloud probe that is part of the Langley Aerosol Research Group Experiment (LARGE) instrument suite. It collects samples of liquid cloud water by using inertial separation to remove cloud droplets from the airflow. These droplets are collected and later used for chemical analysis using techniques such as ion chromatography. A shutter is used to prevent contamination from aerosols.
The Condensation Nuclei Counter (CNC) is optical method for
counting atmospheric aerosol particles.
Earth Science > >
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 NOAA Frost Point Hygrometer (FPH) is a balloon-borne sensor that collects profile measurements of atmospheric water vapor. It employs the chilled-mirror principle to determine the frost or dew point temperature up to 28 km in the atmosphere. FPH takes measurements with a vertical resolution of 5-10 m and a temporal resolution of 1-2 seconds.
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Profiles
Earth Science > Atmosphere > Atmospheric Water Vapor
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Dew Point Temperature
The Cloud Imaging Probe (CIP) is an in situ airborne optical array probe manufactured by Droplet Measurement Technologies. It captures cloud particle images by recording shadows as particles pass through a laser. Additionally, it provides data on particle size distribution and cloud liquid water content. CIP typically has a resolution of 25 μm and can measure particles ranging from 12.5 μm to 1.55 mm.
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.
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 Cloud and Aerosol Spectrometer (CAS) is an in situ airborne spectrometer manufactured by Droplet Measurement Technologies. It measures light scattering at 658 nm to determine aerosol and cloud particle size distributions from 0.51 to 50 μm. It also provides measurements of the refractive index and particle shape. CAS has a typical time resolution of 1 Hz and can measure concentrations greater than 1,000 particles per cubic meter.
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 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.
