The SUbsonic aircraft: Contrail and Clouds Effects Special Study (SUCCESS) was a NASA field investigation that examined how subsonic aircraft affect contrails, cirrus, clouds, and atmospheric chemistry. SUCCESS involved a single deployment during the boreal spring of 1996 across central and western regions of the United States. NASA’s ER-2, DC-8, and T-39 aircraft were equipped with remote sensing and in situ sensors to collect data on cloud properties, aerosols, contrails, and radiation. The Department of Energy (DoE) Atmospheric Radiation Measurements Program (ARM) supported ground-based measurements through the operation of the Clouds and Radiation Testbed (CART) site in northern Oklahoma and southern Kansas. SUCCESS was funded by NASA's Subsonic Assessment Program (SASS) and the Radiation Sciences Program.
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 Cloud Lidar System (CLS) was an airborne lidar system that operated on the ER-2 aircraft. It measured lidar backscatter to determine the height structure of clouds, cloud thickness, and other cloud properties. CLS was also used to determine aerosol properties. It used a Nd-YAG operating at 1064 and 532 nm and had a pulse repetition frequency of 10 Hz. CLS had a horizontal resolution of 20 m and a vertical sampling resolution of 7.5 m.
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.
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Profiles
Earth Science > Atmosphere > Atmospheric Temperature
Earth Science > Atmosphere > Atmospheric Water Vapor
The RC-10 Mapping Camera was an airborne imaging system built by Wild Heerburg. It was a metric mapping camera with a shutter intervalometer designed to capture stereo imagery. It functioned across the 510 to 900 nm spectral range and had a typical resolution of 1.5 to 4 meters. The camera featured a 9x9 image format and was mounted in the Q-bay, nose pod, and both left and right wing pods of NASA’s ER-2 aircraft.
Digital cameras are used to provide imagery for research applications. Cameras are used on aircraft to collect aerial imagery for mapping and surveying, environmental monitoring, cloud observations, agriculture, geological studies, and other Earth science applications. They are also used at field sites to capture visual observations to monitor changes in land cover, vegetation, clouds, air quality, glaciers, and other phenomena.
The MODIS Airborne Simulator (MAS) is an airborne multispectral spectrometer designed to simulate the satellite instrument Moderate-Resolution Imaging Spectrometer (MODIS). MAS operates over 50 spectral channels in the 0.55 to 14.2 μm range, providing high-resolution images of clouds and surface features. It has a horizontal spatial resolution of 50 meters and a swath width of about 36 kilometers at an altitude of 20 km at nadir. Its scan rate is 6.25 Hz, with each scan line containing 716 pixels.
The Radiation Measurement System (RAMS) is an airborne passive radiometer that measures broadband solar irradiance. RAMS includes two radiometers: the Total Solar Broadband Radiometer (TSBR) and the Fractional Solar Broadband Radiometer (FSBR). The TSBR operates in the 0.224 to 3.91 μm range, while the FSBR operates between 0.68 and 3.3 μm. It has a response time of approximately 60 milliseconds and can provide measurements every 5 meters for aircraft speeds around 75 m/s. RAMS is primarily used for airborne operations but can also be used to collect ground-based measurements.
Earth Science > Atmosphere > Atmospheric Radiation > Solar Irradiance
The Millimeter-wave Imaging Radiometer (MIR) was a passive airborne cross-track scanning radiometer developed by NASA. MIR measured brightness temperature across nine channels and was used for studying clouds, precipitation, and atmospheric water vapor. MIR operated near and around the following frequencies: 89, 150, 183, 220, and 325 GHz. It had an angular swath of 100 degrees and a sampling interval of 3 seconds. MIR usually operated on NASA ER-2 aircraft before being retired.
Earth Science > Spectral/engineering > Infrared Wavelengths > Brightness Temperature
Earth Science > Atmosphere > Precipitation
Earth Science > Spectral/engineering > Microwave > Brightness Temperature
Earth Science > Atmosphere > Clouds
Earth Science > Atmosphere > Atmospheric Water Vapor
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.
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 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.
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-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 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 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
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
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 Raman Lidar (RL) is a ground-based lidar system operated by the Department of Energy’s (DoE) Atmospheric Radiation Measurement (ARM) User Facility. It detects Raman backscatter in the ultraviolet range (355 nm) to provide profiles of water vapor, temperature, and aerosol and cloud optical properties. It also detects Raman backscatter from water vapor at 408 nm and molecular nitrogen at 387 nm to help derive aerosol optical properties and water vapor mixing ratios. It has a range resolution of 7.5 m, a time resolution of 10 seconds, and a pulse repetition frequency of 30 Hz. RL can deliver profile measurements from approximately 200 m up to 10 km above ground level.
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.
Video cameras capture video recordings of various phenomena for research purposes. They are used on aircraft to provide continuous views of weather and terrain below the flight path. Video cameras are also employed to verify the aircraft's flight track. Additionally, they are deployed at field sites to monitor changes in vegetation, land cover, clouds, air quality, glaciers, and other Earth science phenomena.
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.
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
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
Digital cameras are used to provide imagery for research applications. Cameras are used on aircraft to collect aerial imagery for mapping and surveying, environmental monitoring, cloud observations, agriculture, geological studies, and other Earth science applications. They are also used at field sites to capture visual observations to monitor changes in land cover, vegetation, clouds, air quality, glaciers, and other phenomena.
The microwave radiometers (MWRs) are ground-based radiometers manufactured by Radiometrics Corporation and operated by the Atmospheric Radiation Measurement (ARM) Research Facility. MWR measures brightness temperature at 23.8 and 31.4 GHz to determine the column amounts of water vapor and liquid water in the atmosphere. MWR has a field of view (FOV) ranging from about 5.9 to 4.5 degrees depending on the channel and typically has a time resolution of 20 seconds for sky-view observations.
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Water Vapor
Earth Science > Spectral/engineering > Microwave > Brightness Temperature
Earth Science > Atmosphere > Atmospheric Water Vapor
The Atmospheric Emitted Radiance Interferometer (AERI) is a ground-based passive interferometer developed by the University of Wisconsin Space Science and Engineering Center (UW-SSEC) for the Department of Energy (DoE) Atmospheric Radiation Measurement (ARM) Program. It uses Fourier transform spectroscopy to measure downwelling thermal infrared emissions from the atmosphere. These measurements can be used to provide profile measurements of atmospheric temperature and water vapor and detect trace gases. AERI operates across the 3.3-19 μm spectral range and up to 25 μm for the extended range version of the instrument. It has an optimal vertical resolution of 100 meters and completes a full sky scan about every 20 seconds.
The Radiation Measurement System (RAMS) is an airborne passive radiometer that measures broadband solar irradiance. RAMS includes two radiometers: the Total Solar Broadband Radiometer (TSBR) and the Fractional Solar Broadband Radiometer (FSBR). The TSBR operates in the 0.224 to 3.91 μm range, while the FSBR operates between 0.68 and 3.3 μm. It has a response time of approximately 60 milliseconds and can provide measurements every 5 meters for aircraft speeds around 75 m/s. RAMS is primarily used for airborne operations but can also be used to collect ground-based measurements.
Earth Science > Atmosphere > Atmospheric Radiation > Solar Irradiance
W-band radars are highly sensitive radars used for atmospheric research. They operate around the 94-95 GHz frequency band, allowing for the detection of small water droplets. W-band radars are used for cloud and precipitation studies since they can provide more detailed observations than typical weather radars. They can be deployed on research vessels, aircraft, and mobile ground-based platforms.
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
Infrared Thermometers (IRTs) are ground-based pyrometers that measure the brightness temperature of a scene within their field of view. They determine brightness temperature by detecting electromagnetic radiation emitted by Earth’s surface. These measurements are used to find either the surface skin temperature or the sea surface temperature, depending on whether the platform is on land or water. IRTs typically operate within the 8- to 14-μm wavelength range.
Earth Science > Spectral/engineering > Infrared Wavelengths > Brightness Temperature
Earth Science > Oceans > Ocean Temperature > Sea Surface Temperature
Earth Science > Atmosphere > Atmospheric Temperature > Surface Temperature
Earth Science > Atmosphere > Atmospheric Temperature > Surface Temperature > Skin Temperature
The Polarization Diversity Lidar (PDL) is a ground-based mobile lidar system developed at the University of Utah. It is a dual-wavelength (1.06 and 0.532 μm) scanning lidar system that simultaneously measures backscatter and depolarization at both wavelengths to characterize clouds and aerosols. It has a spatial resolution of 1.5 meters and a temporal resolution of 0.1 seconds.
The Total Sky Imager (TSI) is a ground-based, optical instrument developed by Yankee Environmental Systems (YES), Inc. TSI provides full-color, hemispheric images of the sky during the day using a charge-coupled device (CCD) imager. It also measures fractional sky cover and sun obscuration caused by clouds. TSI can be mounted on mobile platforms such as trailers and research vehicles, enabling it to collect cloud cover data in different locations during field studies.
The Fourier Transformation Spectrometer (FTS) is a high-resolution spectrometer used both in airborne and ground-based applications. FTS measures the solar radiance reflected from the surface, which can be used to estimate levels of carbon monoxide (CO), carbon dioxide (CO2), and methane (CH4) in the atmosphere. It offers a spatial resolution of approximately 100m by 1000m and operates at a measurement frequency of 1 Hz during typical research flights.
The Micropulse Lidar (MPL) is a ground-based lidar system used for cloud detection. It measures lidar backscatter at 532 nm to retrieve cloud properties such as cloud top and base height. It can also be used for the detection of aerosols. MPL has a vertical resolution of 15 m and a maximum range of 18 km. MPL can operate autonomously and typically provides 10-second averaged data.
Earth Science > Spectral/engineering > Lidar > Lidar Depolarization Ratio
The Radio Acoustic Sounding System (RASS) is an active ground-based acoustic sounder that provides profiles of virtual temperature. It uses radar techniques to measure acoustic disturbances and derive the virtual temperature. RASS is typically used alongside radar wind profilers (RWPs) and operates at frequencies of 915 MHz and 1290 MHz. It has a sampling rate of approximately 5 to 15 minutes, a vertical resolution of 150 m, and a horizontal resolution of 60 m.
Earth Science > Atmosphere > Atmospheric Temperature > Surface Temperature > Boundary Layer Temperature
Earth Science > Atmosphere > Atmospheric Temperature > Upper Air Temperature > Vertical Profiles
Earth Science > Atmosphere > Atmospheric Temperature > Upper Air Temperature > Virtual Temperature
The NOAA/WPL Pulsed Coherent Doppler Lidar is a ground-based lidar system developed by the NOAA Wave Propagation Laboratory (WPL). It measures radial velocity as a function of range using light-scattering particles in the air as tracers to derive wind profiles and momentum fluxes. It operates at a wavelength of 10.59 μm and has a pulse repetition rate from 1 to 20 Hz. It provides velocity azimuth display (VAD) scans, range height indication (RHI), and volume or roster scans at a range resolution of 150 meters.
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 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 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.
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.
The Multiple-Angle Aerosol Spectrometer Probe (MASP) is an in situ airborne spectrometer. It measures the light intensity of scatter aerosol particles at 780 nm wavelength across multiple angles to determine particle size and concentration. It can detect particles within the 0.3 to 20 micron size range. MASP typically has a time resolution of 10 seconds.
The Particule Volume Matter (PVM-100A) is an in situ airborne cloud probe manufactured by Gerber Scientific. It measures liquid water content and the effective radius of cloud droplets by measuring the scattering intensity proportional to the droplets' density and particle surface area density. PVM-100A operates at 780 nm and has a measurement rate of up to 5000 Hz. It can measure droplets in the size range of 3-50 μm diameter. The ground-based model of this instrument is PVM-100.
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 Radiation Measurement System (RAMS) is an airborne passive radiometer that measures broadband solar irradiance. RAMS includes two radiometers: the Total Solar Broadband Radiometer (TSBR) and the Fractional Solar Broadband Radiometer (FSBR). The TSBR operates in the 0.224 to 3.91 μm range, while the FSBR operates between 0.68 and 3.3 μm. It has a response time of approximately 60 milliseconds and can provide measurements every 5 meters for aircraft speeds around 75 m/s. RAMS is primarily used for airborne operations but can also be used to collect ground-based measurements.
Earth Science > Atmosphere > Atmospheric Radiation > Solar Irradiance
The Airborne Tropospheric Hydrogen Oxides Sensor (ATHOS) is an in situ airborne sensor developed by Penn State University. ATHOS uses a laser-induced fluorescence (LIF) technique to measure hydroxide (OH) and hydroperoxyl (HO2) in the atmosphere. ATHOS operates near the 308 nm wavelength, has a pulse repetition frequency of 3 kHz, and has a typical time resolution of 20-30 seconds. It was designed to be installed on NASA’s DC-8 aircraft and can collect measurements of OH and HO2 in clear sky and light cloud conditions.
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. If conditions are stable, the CFDC can also measure flow rate, temperature, and humidity. 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
The 2D-C/P Hydrometeor Imaging Probe (2D-C/P) is an in situ, airborne instrument that captures images of hydrometeors. It records these images by detecting the illuminated or shadowed states of the photodiode array as the shadow of the hydrometeors passes over. 2D-C/P also offers measurements of particle size distribution, cloud droplet concentration, and hydrometeor shape. Typically, 2D-C/P probes have an image resolution of 25 micrometers and can image hydrometeors with diameters up to 1600 micrometers.
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 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
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 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 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.
