The Photochemistry of Ozone Loss in the Arctic Region In Summer (POLARIS) campaign was designed to understand the seasonal behavior of polar stratospheric ozone as it changes from very high concentrations in spring down to very low concentrations in autumn. POLARIS had three deployments based out of California, Alaska, and Hawaii in the boreal spring, summer, and fall of 1997. Airborne observations of nitrogen, halogen, and hydrogen families, as well as aerosols, were supplemented 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 thermal emissions from oxygen molecules in the atmosphere to prove temperature profiles above, below, and at flight level. It operates between 55 to 59 GHz and provides profiles every 17 seconds with 4 km horizontal spacing. MTP has a vertical resolution of 150 m near the aircraft.
Earth Science > Spectral/engineering > Microwave > Brightness Temperature
The Airborne Tunable Laser Absorption Spectrometer (ATLAS) is an in situ airborne spectrometer developed by NASA. ATLAS utilizes second-harmonic absorption spectrometry to measure trace gases in the lower stratosphere such as nitrous oxide, methane, carbon monoxide, and ozone. The laser within ATLAS is tuned to the infrared absorption band of the target gas and is frequency modulated at 2 kHz with the second-harmonic detection occurring at 4 kHz. ATLAS provides measurements at a time resolution of 1 s and has a spatial resolution of about 200 m when deployed on the ER-2 aircraft.
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 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 designed at NASA’s Langley Research Center (LaRC). It uses four lasers to detect lidar backscatter to provide profile measurements of ozone and aerosols in the atmosphere. DIAL operates in the ultraviolet (289-300 nm) for ozone measurements and operates in the visible (572-600 nm) and infrared (1064 nm) for aerosols. It has a horizontal spatial resolution of approximately 15 km and has 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 samples of air for analysis of trace gases, such as nonmethane hydrocarbons (NMHCs), Halocarbons, Alkyl Nitrates, and various sulfur compounds that are present in the troposphere. Air samples collected via the WAS then undergo gas chromatography and mass spectrometry to determine which gasses are present in the sample. The WAS collects samples every minute, which enables scientists to get a clear picture of the chemical composition of the environment 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 the 254 nm wavelength allowing it to calculate the ozone number density due to the accurate ozone absorption cross section at that wavelength. It has a sampling rate of 2 Hz and a horizontal resolution of 100 to 200 meters at typical research flight speeds.
Earth Science > Atmosphere > Air Quality > Tropospheric Ozone
The Aircraft Laser Infrared Absorption Spectrometer (ALIAS) is a high-resolution spectrometer developed by the Jet Propulsion Laboratory (JPL) to fly aboard the NASA ER-2. ALIAS takes real-time measurements of various nitrogen, carbon, and hydrogen compounds, including NO2, CH4, and HCl. Its ability to be flown at high altitudes paired with its fast sample rate makes the ALIAS an ideal instrument to study atmospheric chemistry processes within polar stratospheric clouds (PSCs).
The Focused Cavity Aerosol Spectrometer (FCAS) is an in situ airborne optical particle counter designed by Particle Measuring Systems, Inc. FCAS measures the light scattered by the individual aerosol particles to determine the particle size distribution. It can detect aerosol particles in the size range of 0.06 to 2 μm and can operate at altitudes up to 20 km. Typically, FCAS provides measurements at a sampling rate of 10 seconds.
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 consists of two instruments with distinctly 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 limit systematic errors while in flight. It provides measurements of water vapor mixing ratio from 1 to 1000 ppmv at a frequency of 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 that operates at 1.37 μm to measure atmospheric water vapor in the upper troposphere and lower stratosphere. JLH has a minimum spatial resolution of 25 m and a detection range of 1 to 500 ppmv. It has a typical sampling rate of 1 Hz and can provide measurements at 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. It provides measurements of nitrogen oxides and ozone in the atmosphere at a spatial resolution better than 100m for typical DC-8 research flight speeds. NOx/NOxy can be utilized on ground-based, airborne, and shipborne platforms allowing it to be used in various types of 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 for measuring atmospheric state parameters. MMS provides high-resolution and accurate measurements of atmospheric pressure, temperature, and wind direction/speed immediately around the plane. Additional parameters can be derived such as 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
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. It was originally designed to fly on NASA’s Global Hawk Uncrewed Aircraft System (UAS), but it can deployed on other high-altitude aircraft. It utilizes second harmonic detection near the 2.7 μm wavelength to measure water vapor. It has a typical sampling frequency of 1 Hz.
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Water Vapor
Earth Science > Atmosphere > Atmospheric Water Vapor
The Aircraft Laser Infrared Absorption Spectrometer (ALIAS) is a high-resolution spectrometer developed by the Jet Propulsion Laboratory (JPL) to fly aboard the NASA ER-2. ALIAS takes real-time measurements of various nitrogen, carbon, and hydrogen compounds, including NO2, CH4, and HCl. Its ability to be flown at high altitudes paired with its fast sample rate makes the ALIAS an ideal instrument to study atmospheric chemistry processes within polar stratospheric clouds (PSCs).
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 that was developed at NASA Ames Research Center. Argus collects in situ measurements of carbon monoxide (CO), nitrous oxide (N2O), and methane (CH4) in the atmosphere by 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 of 0.1 to 0.5 Hz. Argus is ideal for small payload platforms such as balloons and uncrewed aerial vehicles (UAV) due to its lightweight and compact design.
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 the 254 nm wavelength allowing it to calculate the ozone number density due to the accurate ozone absorption cross section at that wavelength. It has a sampling rate of 2 Hz and a horizontal resolution of 100 to 200 meters at typical research flight speeds.
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 airborne and ground-based spectrometer. FTS measures the solar radiance reflected from the surface, which can be used to derive measurements of carbon monoxide (CO), carbon dioxide (CO2), and methane (CH4) in the atmosphere. It has a spatial resolution of around 100m x 1000m and a measurement frequency of 1 Hz for typical research flight conditions.
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.
