The Arctic Radiation-Cloud-Aerosol-Surface Interaction EXperiment (ARCSIX) was a NASA field campaign to measure how surface properties, clouds, aerosols, and precipitation affect the Arctic summertime surface radiation budget and sea ice melt. ARCSIX involved two deployments based in Greenland from May to August 2024. The NASA P-3, G-III, and SPEC Learjet aircraft were equipped with both in situ and remote sensing sensors to gather radiation data and analyze aerosol and cloud properties across the Arctic. Additional ground-based observations were collected at the Thule High Arctic Atmospheric Observatory (THAAO) in Pituffik, Greenland. ARCSIX was funded by NASA’s Radiation Sciences and Cryospheric Sciences Programs.
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Profiles
Earth Science > Atmosphere > Aerosols
Earth Science > Atmosphere > Atmospheric Temperature > Upper Air Temperature > Boundary Layer Temperature
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 Differential Aerosol Sizing and Hygroscopicity Spectrometer Probe (DASH-SP) is an in situ airborne spectrometer developed by Brechtel Manufacturing, Inc. It uses differential mobility analysis (DMA) combined with multiple humidification and sizing modules to measure aerosol optical size and hygroscopic growth factors. The probe can deliver faster measurement resolution compared to other hygroscopicity techniques. DASH-SP measures aerosol particles in the size range of 0.1–1.0 μm and operates at a wavelength of 532 nm. Its typical sampling rate is 1 Hz.
The Fast Integrated Mobility Spectrometer (FIMS) is an in situ airborne spectrometer that measures aerosol size distributions. It separates charged aerosol particles based on their electrical mobility and then uses a charge-coupled device (CCD) imaging system to determine a particle size distribution. FIMS can measure aerosol size distributions from 8 to 600 nm at a sampling rate of 1 Hz.
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 G-band Vapor Radiometer (GVR) is an airborne passive radiometer developed by ProSensing, Inc. It measures brightness temperature at 183.31 GHz to determine precipitable water vapor and liquid water path. GVR is highly sensitive to water vapor, making it ideal for measurements in low-humidity conditions. It has an antenna beamwidth of 1.5 degrees and a data rate of up to 20 Hz. GVR can be configured for ground-based operations and has been used at the Department of Energy (DoE) Atmospheric Radiation Measurement (ARM) Central Facility site in Barrow, Alaska.
Earth Science > Spectral/engineering > Microwave > Brightness Temperature
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Total Precipitable Water
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).
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 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 Continuous Flow Diffusion Chamber (CFDC) is an in situ airborne optical particle counter (OPC). It uses vertical flow through two chambers with different wall temperatures to grow ice particles inside the OPC at the bottom of the instrument, which helps determine particle size distribution. The CFDC can also measure flow rate, temperature, and humidity if conditions are stable. It measures the size distribution of aerosol particles ranging from 0.4 to 20 mm. The device counts particles every 0.2 seconds and records particle spectra every 10 seconds.
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Humidity
Earth Science > Atmosphere > Atmospheric Temperature > Upper Air Temperature
A pyrometer is a remote-sensing infrared thermometer that measures the temperature of distant objects. It determines an object's temperature by detecting its thermal radiation. It can be mounted on aircraft, ground vehicles, or water-based platforms for surface and sea surface temperature observations. For atmospheric studies, the pyrometer usually operates in the 9.6 to 11.5 µm spectral range and has a temperature range of -25 to 200 degrees Celsius. Pyrometers typically have a response time between 5 milliseconds and 600 seconds.
Earth Science > Oceans > Ocean Temperature > Sea Surface Temperature
Earth Science > Atmosphere > Atmospheric Temperature > Surface Temperature > Skin Temperature
Earth Science > Atmosphere > Atmospheric Temperature > Surface Temperature
Earth Science > Spectral/engineering > Infrared Wavelengths > Brightness Temperature
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 optical method for
counting atmospheric aerosol particles.
Earth Science > >
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 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 Land, Vegetation, and Ice Sensor (LVIS) is an airborne imaging lidar developed and operated by Goddard Space Flight Center (GSFC). It is used to create topographical maps and examine the vertical structure of vegetation and ice. It has an operating wavelength of 1064 nm and pulse repetition rates up to 500 Hz. LVIS features a swath width of 2 km and a horizontal resolution of 20 m at a flight altitude of 10 km.
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 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 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 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.
The Airborne Visible InfraRed Imaging Spectrometer—Next Generation (AVIRIS-NG) is an airborne imaging spectrometer developed by the Jet Propulsion Laboratory (JPL). It collects visible and infrared imagery, mainly used for terrestrial ecology research. It operates between 380 and 2510 nm at a spectral resolution of 5 nm. It has a horizontal resolution of 8 m and a swath width of 4 km at an altitude of 8 km. It has a measurement frequency of 100 Hz. It was designed to replace the AVIRIS Classic (AVIRIS-C).
The High Altitude Lidar Observatory (HALO) is an airborne lidar system developed by NASA's Langley Research Center. HALO operates on four wavelengths (1645, 1064, 935, 532 nm) and combines Differential Absorption Lidar (DIAL) with High Spectral Resolution Lidar (HSRL) techniques to measure lidar backscatter and depolarization ratio. It provides vertical profiles of aerosol and cloud optical properties, atmospheric water vapor, and methane at a data rate of 2 Hz. HALO has a nominal spatial resolution of 12 km horizontally and 315 m vertically at an altitude of 10 km.
Earth Science > Spectral/engineering > Lidar > Lidar Depolarization Ratio
The High Spectral Resolution Lidar (HSRL) is an airborne lidar system developed at NASA Langley Research Center (LaRC). It uses the HSRL technique at 532 nm and the standard backscatter technique at 1064 nm to provide profile measurements of aerosol backscatter, extinction, and depolarization. The profiles of aerosol backscatter and depolarization typically have a vertical resolution of 30 m and a horizontal resolution of about 1 km. For the extinction profiles, the vertical resolution is 300 m with a horizontal resolution of approximately 6 km. HSRL is usually flown during investigations to validate observations from the CALIPSO spaceborne lidar.
Earth Science > Spectral/engineering > Lidar > Lidar Depolarization Ratio
The Airborne Vertical Atmospheric Profiling System (AVAPS) is an airborne system that uses dropsondes and Global Positioning System (GPS) receivers to gather in situ profiles of atmospheric parameters. It provides profile measurements of temperature, pressure, and humidity every 0.5 seconds, and atmospheric wind measurements every 0.25 seconds. AVAPS has a vertical resolution of approximately 10 meters and can launch dropsondes every 20 seconds. Developed by the National Center for Atmospheric Research (NCAR) for the NASA Global Hawk, it can also be deployed on other aircraft such as the DC-8 and P-3.
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Humidity
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.
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
A pyrometer is a remote-sensing infrared thermometer that measures the temperature of distant objects. It determines an object's temperature by detecting its thermal radiation. It can be mounted on aircraft, ground vehicles, or water-based platforms for surface and sea surface temperature observations. For atmospheric studies, the pyrometer usually operates in the 9.6 to 11.5 µm spectral range and has a temperature range of -25 to 200 degrees Celsius. Pyrometers typically have a response time between 5 milliseconds and 600 seconds.
Earth Science > Oceans > Ocean Temperature > Sea Surface Temperature
Earth Science > Atmosphere > Atmospheric Temperature > Surface Temperature > Skin Temperature
Earth Science > Atmosphere > Atmospheric Temperature > Surface Temperature
Earth Science > Spectral/engineering > Infrared Wavelengths > Brightness Temperature
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.
Earth Science > Spectral/engineering > Microwave > Brightness Temperature
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 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.
The Micro Rain Radar (MRR) is a ground-based, vertically oriented, continuous wave K-band (24.23 GHz) radar that measures various parameters of precipitation, such as liquid water content and rain rate, from near ground level to the lower troposphere. The backscatter captured by the MRR’s antenna can determine precipitation size distributions ranging from 0.25 mm to 4.53 mm and can also calculate the frequency shift of falling precipitation to determine its velocity. Additional uses of the MRR include identifying bright bands, nowcasting precipitation, and tracking chemical transport during precipitation events. It has a range resolution of 10 to 200 meters and a sampling time of 10 seconds.
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 Forward Scattering Spectrometer Probe (FSSP) is an in situ airborne optical particle counter initially developed by Particle Measuring Systems, Inc. It determines particle size distribution by measuring the light intensity scattered by individual particles within the cloud. FSSP can detect particles ranging from 0.5 to 47 μm in diameter. It functions at a wavelength of 633 nm and typically samples at a rate of 1 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 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.
