The Photochemistry of Ozone Loss in the Arctic Region In Summer (POLARIS) campaign aimed to understand the seasonal behavior of polar stratospheric ozone as it shifts from very high concentrations in spring to very low levels in autumn. POLARIS involved three deployments based in California, Alaska, and Hawaii during the boreal spring, summer, and fall of 1997. Airborne observations of nitrogen, halogen, and hydrogen compounds, along with aerosols, were complemented by balloon measurements such as ozonesondes and radiosondes. POLARIS was funded by NASA in partnership with NOAA.
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
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 Submillimeter Limb Sounder (SLS) was a passive heterodyne radiometer designed for high-altitude balloons and aircraft. It measured thermal emission spectra around 640 GHz to detect chlorine monoxide (ClO), hydrogen chloride (HCl), and ozone (O3), and at 604 GHz for nitric acid (HNO3) and nitrous oxide (N2O). It had a field of view of 0.3 degrees, resulting in a vertical resolution of 1.5 km at an altitude of 25 km. SLS completed a full scan in approximately 300 seconds.
The Focused Cavity Aerosol Spectrometer (FCAS) is an in situ airborne optical particle counter developed by Particle Measuring Systems, Inc. FCAS detects light scattered by individual aerosol particles to determine their size distribution. It can detect aerosol particles ranging from 0.06 to 2 μm in size and operate at altitudes up to 20 km. Typically, FCAS provides measurements every 10 seconds.
The High-Sensitivity Fast-Response CO2 Analyzer (Harvard CO2) is an in situ airborne spectrometer operated by Harvard University. It measures carbon dioxide (CO2) concentrations using a modified nondispersive infrared CO2 analyzer. CO2 mixing ratios are determined by measuring absorption at 4.26 μm. Harvard CO2 has a measurement sampling rate of 0.5 Hz and a precision of 0.05 ppm. Harvard is typically deployed on high-altitude aircraft like the ER-2, but it has been used for balloon-borne measurements.
The Differential Absorption Lidar (DIAL) is an airborne lidar system developed at NASA’s Langley Research Center (LaRC). It uses four lasers to detect lidar backscatter and provide profile measurements of ozone and aerosols in the atmosphere. DIAL operates in the ultraviolet (289-300 nm) for ozone detection and in the visible (572-600 nm) and infrared (1064 nm) for aerosols. It has a horizontal spatial resolution of approximately 15 km and a measurement accuracy of 5 ppbv.
Earth Science > Spectral/engineering > Lidar > Lidar Depolarization Ratio
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 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 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 Airborne Laser Infrared Absorption Spectrometer (ALIAS) is an in situ airborne spectrometer developed by the Jet Propulsion Laboratory. It can also be deployed on balloons. It uses mid-infrared (3.4–8 μm) absorption spectroscopy to measure atmospheric gases such as nitrous oxide (N2O), nitrogen dioxide (NO2), nitric acid (HNO3), hydrochloric acid (HCl), carbon monoxide (CO), and methane (CH4). ALIAS has a vertical resolution of 15 m and a time resolution of 3 seconds or less.
Harvard Water Vapor (HWV) is an in situ airborne hygrometer developed at Harvard University that measures water vapor mixing ratios in the upper troposphere and lower stratosphere. HWV includes two instruments with different methods for detecting water vapor: the Lyman-α photo-fragment fluorescence instrument (LyA) and a tunable diode laser direct absorption instrument (HHH -Harvard Herriott Hygrometer). By combining both instruments, HWV can identify and reduce systematic errors during flight. It provides measurements of water vapor mixing ratio from 1 to 1000 ppmv at 1 Hz and with an accuracy of 5%.
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Water Vapor
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Profiles > Water Vapor Mixing Ratio Profiles
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators
Earth Science > Atmosphere > Atmospheric Water Vapor
The JPL Laser Hygrometer (JLH) is an in situ airborne hygrometer developed at the Jet Propulsion Laboratory (JPL). It uses a tunable diode laser operating at 1.37 μm to measure atmospheric water vapor in the upper troposphere and lower stratosphere. JLH has a minimum spatial resolution of 25 meters and a detection range of 1 to 500 ppmv. It typically samples at 1 Hz and can provide measurements with a precision of 0.05 ppmv.
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Water Vapor
Earth Science > Atmosphere > Atmospheric Water Vapor
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.
The Harvard Hydroxyl Experiment (HOx) is an in situ laser-induced fluorescence (LIF) sensor developed by Harvard University. It uses LIF centered at 309 nm to measure hydroxyl radical (OH). The OH is then converted into its first electronic state using a tunable ultraviolet laser near 282 nm. The hydroperoxyl radical (HO2) is measured as OH after chemical titration with nitric oxide. HOx has a short integration time of less than 20 seconds.
The Chlorine Nitrate Instrument (ClONO2) is an in situ airborne analyzer used for the detection of nitrogen dioxide (NO2), chlorine monoxide (ClO), bromine monoxide (BrO), and chlorine nitrate (ClONO2). It used laser-induced resonance fluorescence (LIF) at 585 nm for the direct detection of NO2. It provides NO2 measurements in 10-second intervals with an accuracy of approximately 10%. It uses thermal dissociation and ultraviolet (118.9 nm) resonance fluorescence for the detection of ClO, BrO, and ClONO2. It provides ClO and ClONO2 measurements in 35-second intervals with a detection limit of 3 pptv and 10 pptv, respectively.
The Composition and Photodissociative Flux Measurement (CPFM) is an in situ airborne spectroradiometer used for the measurement of direct and scattered solar irradiance. It is based on a holographic, diffraction grating, and a 1024-element photodiode array detector. It measures the solar flux on a horizontal surface and the limb and apparent brightness below the flight level. CPFM operates in the 300-770 nm wavelength range. CPFM has also been used for ground-based measurements.
Earth Science > Atmosphere > Atmospheric Radiation > Solar Irradiance
The Airborne Tunable Laser Absorption Spectrometer (ATLAS) is an in situ airborne spectrometer developed by NASA. ATLAS uses second-harmonic absorption spectrometry to measure trace gases in the lower stratosphere, such as nitrous oxide, methane, carbon monoxide, and ozone. The laser inside ATLAS is tuned to the infrared absorption band of the target gas and is frequency modulated at 2 kHz, with second-harmonic detection happening at 4 kHz. ATLAS provides measurements with a time resolution of 1 second and a spatial resolution of about 200 meters when deployed on the ER-2 aircraft.
NOAA Water (NW) is an airborne, two-channel, closed-path tunable diode laser absorption spectrometer developed by NOAA. It measures water vapor and enhanced total water content in the upper troposphere and lower stratosphere. Originally designed for installation on NASA’s Global Hawk Uncrewed Aircraft System (UAS), it can also be deployed on other high-altitude aircraft. It uses second harmonic detection near the 2.7 μm wavelength to measure water vapor. Its typical sampling frequency is 1 Hz.
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Water Vapor
Earth Science > Atmosphere > Atmospheric Water Vapor
The Airborne Laser Infrared Absorption Spectrometer (ALIAS) is an in situ airborne spectrometer developed by the Jet Propulsion Laboratory. It can also be deployed on balloons. It uses mid-infrared (3.4–8 μm) absorption spectroscopy to measure atmospheric gases such as nitrous oxide (N2O), nitrogen dioxide (NO2), nitric acid (HNO3), hydrochloric acid (HCl), carbon monoxide (CO), and methane (CH4). ALIAS has a vertical resolution of 15 m and a time resolution of 3 seconds or less.
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
The Lightweight Airborne Chromatograph Experiment (LACE) is an in situ balloon-borne, three-channel gas chromatograph. It was designed to operate on the Observations of the Middle Stratosphere (OMS) balloon gondola. It provides profile measurements of various gas species up to 32 km with a vertical resolution of 300 m. LACE measures halon-1211, chlorofluorocarbons, nitrous oxide, and sulfur hexafluoride every 70 seconds. It measures methyl chloroform, carbon tetrachloride, hydrogen, methane, and carbon monoxide every 140 seconds.
Argus is a two-channel, tunable diode laser instrument developed at NASA Ames Research Center. It collects in situ measurements of carbon monoxide (CO), nitrous oxide (N2O), and methane (CH4) in the atmosphere using second harmonic spectroscopy. Argus operates in the mid-infrared range (3.3 and 4.7 micrometers) and has an accuracy of about 3% for data rates between 0.1 and 0.5 Hz. Its lightweight and compact design makes it ideal for small payload platforms such as balloons and uncrewed aerial vehicles (UAVs).
The High-Sensitivity Fast-Response CO2 Analyzer (Harvard CO2) is an in situ airborne spectrometer operated by Harvard University. It measures carbon dioxide (CO2) concentrations using a modified nondispersive infrared CO2 analyzer. CO2 mixing ratios are determined by measuring absorption at 4.26 μm. Harvard CO2 has a measurement sampling rate of 0.5 Hz and a precision of 0.05 ppm. Harvard is typically deployed on high-altitude aircraft like the ER-2, but it has been used for balloon-borne measurements.
The Composition and Photodissociative Flux Measurement (CPFM) is an in situ airborne spectroradiometer used for the measurement of direct and scattered solar irradiance. It is based on a holographic, diffraction grating, and a 1024-element photodiode array detector. It measures the solar flux on a horizontal surface and the limb and apparent brightness below the flight level. CPFM operates in the 300-770 nm wavelength range. CPFM has also been used for ground-based measurements.
Earth Science > Atmosphere > Atmospheric Radiation > Solar Irradiance
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
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
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 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 Submillimeter Limb Sounder (SLS) was a passive heterodyne radiometer designed for high-altitude balloons and aircraft. It measured thermal emission spectra around 640 GHz to detect chlorine monoxide (ClO), hydrogen chloride (HCl), and ozone (O3), and at 604 GHz for nitric acid (HNO3) and nitrous oxide (N2O). It had a field of view of 0.3 degrees, resulting in a vertical resolution of 1.5 km at an altitude of 25 km. SLS completed a full scan in approximately 300 seconds.
The Cold Atmospheric Emission Spectral Radiometer (CAESR) is a balloon-borne scanning passive radiometer developed at the University of Denver. It measures thermal emission in the 7.5-12.6 μm spectral range. These measurements are used to derive nitric acid profiles (HNO3) up to 30 km with an effective vertical resolution of 1.5 km. CAESR can complete a scan in less than 10 seconds and has a field of view of about 1.5 degrees.
