The ObseRvations of Aerosols above CLouds and their intEractionS (ORACLES) campaign aimed to understand the processes that lead to climate impacts, such as radiation balance and cloud properties, caused by African biomass burning (BB) aerosols over the Southeast Atlantic Ocean. ORACLES carried out three deployments over the Southeast Atlantic Ocean in 2016, 2017, and 2018. Airborne in situ and remote sensing measurements of aerosols and clouds were collected using a combination of polarimeter, radar, and lidar instruments to improve satellite-based remote sensing. ORACLES was one of NASA’s Earth Venture Suborbital-2 projects.
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 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
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 Solar Spectral Flux Radiometer (SSFR) is an airborne radiometer developed by the Ames Atmospheric Radiation Group. It measures solar spectral irradiance in the troposphere. SSFR works within the 300-2150 nm wavelength range and offers a spectral resolution of 8-12 nm. It typically collects data at 1 Hz and has a radiometric accuracy of 3%.
Earth Science > Atmosphere > Atmospheric Radiation > Solar Irradiance
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 Differential Mobility Analyzer (DMA) is an in situ device that measures particle electrical mobility to determine their size distribution. It mainly measures aerosols between 10 and 1,000 nm in diameter. DMA can be used for airborne, ground-based, and laboratory measurements.
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 Counterflow Virtual Impactor (CVI) is an in situ airborne instrument that samples cloud droplets. It samples cloud droplets by removing them from the surrounding air through inertial impaction. CVI is typically deployed with additional sensors to provide measurements of cloud particle concentration, cloud liquid water, and water vapor of the sample droplets. CVI can detect cloud droplets as small as 7 microns in diameter and has a typical time response 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.
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.
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 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 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 Passive-Cavity Aerosol Spectrometer Probe (PCASP) is an in situ airborne optical spectrometer manufactured by Droplet Measurement Technologies. It detects light scattered by particles to determine aerosol size distribution and concentration within the 0.1 to 3.0 μm range. PCASP operates at a wavelength of 632 nm and typically samples at 10 Hz.
The Airborne Third Generation Precipitation Radar (APR-3) is an airborne Doppler dual-polarization radar. It measures Doppler velocity and radar reflectivity at three frequencies: 13.4 GHz, 35.6 GHz, and 94 GHz. These measurements are used to determine the vertical structures of clouds and precipitation characteristics. APR-3 has a horizontal resolution of 700-800 meters at an altitude of 10 km and a vertical resolution of 60 meters. It was developed by NASA's Jet Propulsion Laboratory (JPL) and replaced the APR-2.
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 Spectrometers for Sky-Scanning, Sun-Tracking Atmospheric Research (4-STAR) is an airborne sun-sky spectrometer that measures direct solar irradiance and sky radiance. These measurements can be used to retrieve column-integrated information on aerosols, clouds, and trace gases such as aerosol optical depth, extinction, and single scattering albedo. 4-STAR operates in the 350-1650 nm wavelength range and has a typical horizontal resolution of about 100 m.
The Advanced Microwave Precipitation Radiometer (AMPR) is an airborne passive microwave radiometer. AMPR provides calibrated brightness temperatures, which can be used to determine cloud and precipitation characteristics. It operates across four microwave channels: 10.7, 19.35, 37.1, and 85.5 GHz. These frequencies are sensitive to precipitation, making AMPR well-suited for studying rain events. It has a surface footprint size ranging from 640 m (85.5 GHz) to 2.8 km (10.7 GHz).
Earth Science > Spectral/engineering > Microwave > Brightness Temperature
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 Solar Spectral Flux Radiometer (SSFR) is an airborne radiometer developed by the Ames Atmospheric Radiation Group. It measures solar spectral irradiance in the troposphere. SSFR works within the 300-2150 nm wavelength range and offers a spectral resolution of 8-12 nm. It typically collects data at 1 Hz and has a radiometric accuracy of 3%.
Earth Science > Atmosphere > Atmospheric Radiation > Solar Irradiance
The Water Isotope System for Precipitation and Entrainment Research (WISPER) is an in situ airborne instrument used to measure condensed water content and water vapor. It consists of two inlets with the primary inlet being a counterflow virtual impactor (CVI) used to collect air samples. Picarro cavity ringdown laser spectrometers (CRDS) are used to measure condensed water and water vapor within the air samples. WISPER can also provide water vapor isotopic abundances. It has a typical sampling frequency of 1 second.
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Water Vapor
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators
Earth Science > Atmosphere > Atmospheric Water Vapor
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.
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 Phase Doppler Interferometer (PDI) is an in situ airborne interferometer developed by Artium Technologies, Inc. It is based on light scattering interferometry and laser Doppler velocimetry to measure the size and velocity of spherical cloud particles. It operates at wavelengths of 491, 532, 561, and 660 nm and has a measurement duration of 1 second. PDI can measure droplet sizes from 0.3 to 6000 μm and velocities from -600 to 1000 meters per second
The King Probe is an in situ airborne cloud instrument developed by Warren King (Commonwealth Scientific and Industrial Research Organisation) and manufactured by Particle Measuring Systems (PMS) and Droplet Measurement Technologies (DMT). The King Probe measures cloud liquid water content (LWC) by detecting the heat released when water droplets vaporize. It operates at a constant temperature of approximately 100°C and has a data output rate of 1 to 10 Hz. The probe is commonly used in studies of cloud microphysics and aircraft icing.
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.
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 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 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
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 High Volume Precipitation Spectrometer (HVPS) is an in situ airborne particle imager manufactured by SPEC Inc. It uses a 128-photodiode array to capture images of precipitation particles. These images can be used to determine the particles' shape, size, and concentration. HVPS-3 has a pixel resolution of 150 μm and a maximum field of view of 1.92 cm.
