Airborne Lidar measurements of the atmospheric pressure profile with tunable Alexandrite lasers

NASA Technical Reports Server (NTRS)

Korb, C. L.; Schwemmer, G. K.; Dombrowski, M.; Milrod, J.; Walden, H.

1986-01-01

The first remote measurements of the atmospheric pressure profile made from an airborne platform are described. The measurements utilize a differential absorption lidar and tunable solid state Alexandrite lasers. The pressure measurement technique uses a high resolution oxygen A band where the absorption is highly pressure sensitive due to collision broadening. Absorption troughs and regions of minimum absorption were used between pairs of stongly absorption lines for these measurements. The trough technique allows the measurement to be greatly desensitized to the effects of laser frequency instabilities. The lidar system was set up to measure pressure with the on-line laser tuned to the absorption trough at 13147.3/cm and with the reference laser tuned to a nonabsorbing frequency near 13170.0/cm. The lidar signal returns were sampled with a 200 range gate (30 vertical resoltion) and averaged over 100 shots.

Atmospheric Airborne Pressure Measurements Using the Oxygen A Band for the ASCENDS Mission

NASA Technical Reports Server (NTRS)

Riris, Haris; Rodriguez, Mike; Stephen, Mark; Hasselbrack, William; Allan, Graham; Mao, Jianping; Kawa, Stephen R.; Weaver, Clark J.

2010-01-01

We report on airborne atmospheric pressure measurements using new fiber-based laser technology and the oxygen A-band at 765 nm. Remote measurements of atmospheric temperature and pressure are required for a number of NASA Earth science missions and specifically for the Active Sensing of CO2 Emissions Over Nights, Days, and Seasons (ASCENDS) mission. Accurate measurements of tropospheric CO2 on a global scale are very important in order to better understand its sources and sinks and to improve predictions on any future climate change. The ultimate goal of a CO2 remote sensing mission, such as ASCENDS, is to derive the CO2 concentration in the atmosphere in terms of mole fraction in unit of parts-per-million (ppmv) with regard to dry air. Therefore, both CO2 and the dry air number of molecules in the atmosphere are needed in deriving this quantity. O2 is a stable molecule and uniformly mixed in the atmosphere. Measuring the O2 absorption in the atmosphere can thus be used to infer the dry air number of molecules and then used to calculate CO2 concentration. With the knowledge of atmospheric water vapor, we can then estimate the total surface pressure needed for CO2 retrievals. Our work, funded by the ESTO IIP program, uses fiber optic technology and non-linear optics to generate 765 nm laser radiation coincident with the Oxygen A-band. Our pulsed, time gated technique uses several on- and off-line wavelengths tuned to the O2 absorption line. The choice of wavelengths allows us to measure the pressure by using two adjacent O2 absorptions in the Oxygen A-band. Our retrieval algorithm fits the O2 lineshapes and derives the pressure. Our measurements compare favorably with a local weather monitor mounted outside our laboratory and a local weather station.

Atmospheric Airborne Pressure Measurements Using the Oxygen A Band for the ASCENDS Mission

NASA Technical Reports Server (NTRS)

Riris, Haris; Rodriguez, Mike; Stephen, Mark; Hasselbrack, William; Allan, Graham; Mao, Jiamping,; Kawa, Stephan R.; Weaver, Clark J.

2011-01-01

We report on airborne atmospheric pressure measurements using new fiber-based laser technology and the oxygen A-band at 765 nm. Remote measurements of atmospheric temperature and pressure are required for a number of NASA Earth science missions and specifically for the Active Sensing of CO2 Emissions Over Nights, Days, and Seasons (ASCENDS) mission. Accurate measurements of tropospheric CO2 on a global scale are very important in order to better understand its sources and sinks and to improve predictions on any future climate change. The ultimate goal of a CO2 remote sensing mission, such as ASCENDS, is to derive the CO2 concentration in the atmosphere in terms of mole fraction in unit of parts-per-million (ppmv) with regard to dry air. Therefore, both CO2 and the dry air number of molecules in the atmosphere are needed in deriving this quantity. O2 is a stable molecule and uniformly mixed in the atmosphere. Measuring the O2 absorption in the atmosphere can thus be used to infer the dry air number of molecules and then used to calculate CO2 concentration. With the knowledge of atmospheric water vapor, we can then estimate the total surface pressure needed for CO2 retrievals. Our work, funded by the ESTO IIP program, uses fiber optic technology and non-linear optics to generate 765 nm laser radiation coincident with the Oxygen A-band. Our pulsed, time gated technique uses several on- and off-line wavelengths tuned to the O2 absorption line. The choice of wavelengths allows us to measure the pressure by using two adjacent O2 absorptions in the Oxygen A-band. Our retrieval algorithm fits the O2 lineshapes and derives the pressure. Our measurements compare favorably with a local weather monitor mounted outside our laboratory and a local weather station.

Airborne water vapor DIAL research: System development and field measurements

NASA Technical Reports Server (NTRS)

Higdon, Noah S.; Browell, Edward V.; Ponsardin, Patrick; Chyba, Thomas H.; Grossmann, Benoist E.; Butler, Carolyn F.; Fenn, Marta A.; Mayor, Shane D.; Ismail, Syed; Grant, William B.

1992-01-01

This paper describes the airborne differential absorption lidar (DIAL) system developed at the NASA Langley Research Center for remote measurement of water vapor (H2O) and aerosols in the lower atmosphere. The airborne H2O DIAL system was flight tested aboard the NASA Wallops Flight Facility (WFF) Electra aircraft in three separate field deployments between 1989 and 1991. Atmospheric measurements were made under a variety of atmospheric conditions during the flight tests, and several modifications were implemented during this development period to improve system operation. A brief description of the system and major modifications will be presented, and the most significant atmospheric observations will be described.

A Study of Reflected Sonic Booms Using Airborne Measurements

NASA Technical Reports Server (NTRS)

Kantor, Samuel R.; Cliatt, Larry J.

2017-01-01

In support of ongoing efforts to bring commercial supersonic flight to the public, the Sonic Booms in Atmospheric Turbulence (SonicBAT) flight test conducted at NASA Armstrong Flight Research Center. During this test, airborne sonic boom measurements were made using an instrumented TG-14 motor glider, called the Airborne Acoustic Measurement Platform (AAMP).During the flight program, the AAMP was consistently able to measure the sonic boom wave that was reflected off of the ground, in addition to the incident wave, resulting in the creation of a completely unique data set of airborne sonic boom reflection measurements.

BOREAS RSS-12 Airborne Tracking Sunphotometer Measurements

NASA Technical Reports Server (NTRS)

Hall, Forrest G. (Editor); Nickeson, Jaime (Editor); Lobitz, Brad; Spanner, Michael; Wrigley, Robert

2000-01-01

The BOREAS RSS-12 team collected both ground and airborne sunphotometer measurements for use in characterizing the aerosol optical properties of the atmosphere during the BOREAS data collection activities. These measurements are to be used to: 1) measure the magnitude and variability of the aerosol optical depth in both time and space; 2) determine the optical properties of the boreal aerosols; and 3) atmospherically correct remotely sensed data acquired during BOREAS. This data set contains airborne tracking sunphotometer data that were acquired from the C-130 aircraft during its flights over the BOREAS study areas. The data cover selected days and times from May to September 1994. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

Progress toward improving regional atmospheric inversions using airborne measurements: Results from ACT-America

NASA Astrophysics Data System (ADS)

Davis, K. J.; Baier, B.; Baker, D.; Barkley, Z.; Bell, E.; Bowman, K. W.; Browell, E. V.; Campbell, J.; Chen, H. W.; Choi, Y.; DiGangi, J. P.; Dobler, J. T.; Erxleben, W. H.; Fan, T. F.; Feng, S.; Fried, A.; Gaudet, B. J.; Jacobson, A. R.; Keller, K.; Kooi, S. A.; Lauvaux, T.; Lin, B.; McGill, M. J.; McGregor, D.; Michalak, A.; Obland, M. D.; O'Dell, C.; Pal, S.; Parazoo, N.; Pauly, R.; Randazzo, N. A.; Samaddar, A.; Schuh, A. E.; Sweeney, C.; Wesloh, D.; Williams, C. A.; Zhang, F.; Zhou, Y.

2017-12-01

The Atmospheric Carbon and Transport (ACT) - America mission aims to improve our understanding of transport and fluxes of greenhouse gases (GHGs) via airborne campaigns spanning a range of mid-latitude weather conditions, and thus to improve the accuracy and precision of regional inverse flux estimates of GHGs. ACT-America has conducted three field campaigns with two aircraft across three regions of the eastern United States during summer 2016, winter 2017 and fall 2017. Simulations of atmospheric GHGs have been conducted for a subset of these campaigns. We present progress from these campaigns. Mid-summer observations suggest a net biological source of CO2 to the atmosphere in the Gulf Coast states. These results contradict those terrestrial biosphere models that show net uptake of CO2 in this region in summer. Methane observations downwind of major sources in the MidAtlantic suggest that these sources are represented fairly well by existing emissions inventories. Flux estimation in other regions is underway. Spatially-coherent differences in GHGs extend throughout the depth of the troposphere are observed at frontal boundaries in summer and winter. These spatial structures are captured in global and mesoscale simulations, though the simulated GHG mole fractions are sometimes biased with respect to observations, suggesting potential biases in synoptic transport. Mesoscale simulations overestimate spatial differences in ABL CO2 mole fractions in fair weather conditions as compared to observations and the CarbonTracker global inverse modeling system. ABL depths are simulated fairly well by both mesoscale and global modeling systems, suggesting that either weather-scale flux amplitudes are overestimated by CarbonTracker, or the mesoscale model lacks parameterized transport above the ABL. Measurements of OCS, 14CO2, and CO are being used to attribute CO2 variability to biogenic and anthropogenic processes and to expand the evaluation of GHG simulation systems. Cross

Analysis of airborne Doppler lidar, Doppler radar and tall tower measurements of atmospheric flows in quiescent and stormy weather

NASA Technical Reports Server (NTRS)

Bluestein, H. B.; Doviak, R. J.; Eilts, M. D.; Mccaul, E. W.; Rabin, R.; Sundara-Rajan, A.; Zrnic, D. S.

1986-01-01

The first experiment to combine airborne Doppler Lidar and ground-based dual Doppler Radar measurements of wind to detail the lower tropospheric flows in quiescent and stormy weather was conducted in central Oklahoma during four days in June-July 1981. Data from these unique remote sensing instruments, coupled with data from conventional in-situ facilities, i.e., 500-m meteorological tower, rawinsonde, and surface based sensors, were analyzed to enhance understanding of wind, waves and turbulence. The purposes of the study were to: (1) compare winds mapped by ground-based dual Doppler radars, airborne Doppler lidar, and anemometers on a tower; (2) compare measured atmospheric boundary layer flow with flows predicted by theoretical models; (3) investigate the kinematic structure of air mass boundaries that precede the development of severe storms; and (4) study the kinematic structure of thunderstorm phenomena (downdrafts, gust fronts, etc.) that produce wind shear and turbulence hazardous to aircraft operations. The report consists of three parts: Part 1, Intercomparison of Wind Data from Airborne Lidar, Ground-Based Radars and Instrumented 444 m Tower; Part 2, The Structure of the Convective Atmospheric Boundary Layer as Revealed by Lidar and Doppler Radars; and Part 3, Doppler Lidar Observations in Thunderstorm Environments.

[Remote sensing of atmospheric trace gas by airborne passive FTIR].

PubMed

Gao, Min-quang; Liu, Wen-qing; Zhang, Tian-shu; Liu, Jian-guo; Lu, Yi-huai; Wang, Ya-ping; Xu, Liang; Zhu, Jun; Chen, Jun

2006-12-01

The present article describes the details of aviatic measurement for remote sensing trace gases in atmosphere under various surface backgrounds with airborne passive FTIR. The passive down viewing and remote sensing technique used in the experiment is discussed. The method of acquiring atmospheric trace gases infrared characteristic spectra in complicated background and the algorithm of concentration retrieval are discussed. The concentrations of CO and N2O of boundary-layer atmosphere in experimental region below 1000 m are analyzed quantitatively. This measurement technique and the data analysis method, which does not require a previously measured background spectrum, allow fast and mobile remote detection and identification of atmosphere trace gas in large area, and also can be used for urgent monitoring of pollution accidental breakout.

Development of an Airborne Triple-Pulse 2-Micron Integrated Path Differential Absorption Lidar (IPDA) for Simultaneous Airborne Column Measurements of Carbon Dioxide and Water Vapor in the Atmosphere

NASA Technical Reports Server (NTRS)

Singh, Upendra N.; Petros, Mulugeta; Refaat, Tamer F.; Yu, Jirong; Antill, Charles W.; Remus, Ruben

2016-01-01

This presentation will provide status and details of an airborne 2-micron triple-pulse integrated path differential absorption (IPDA) lidar being developed at NASA Langley Research Center with support from NASA ESTO Instrument Incubator Program. The development of this active optical remote sensing IPDA instrument is targeted for measuring both atmospheric carbon dioxide and water vapor in the atmosphere from an airborne platform. This presentation will focus on the advancement of the 2-micron triple-pulse IPDA lidar development. Updates on the state-of-the-art triple-pulse laser transmitter will be presented including the status of seed laser locking, wavelength control, receiver and detector upgrades, laser packaging and lidar integration. Future plan for IPDA lidar system for ground integration, testing and flight validation will also be presented.

Airborne differential absorption lidar system for measurements of atmospheric water vapor and aerosols

NASA Technical Reports Server (NTRS)

Carter, Arlen F.; Allen, Robert J.; Mayo, M. Neale; Butler, Carolyn F.; Grossman, Benoist E.; Ismail, Syed; Grant, William B.; Browell, Edward V.; Higdon, Noah S.; Mayor, Shane D.;

Mobile Instruments Measure Atmospheric Pollutants

NASA Technical Reports Server (NTRS)

2009-01-01

As a part of NASA's active research of the Earth s atmosphere, which has included missions such as the Atmospheric Laboratory of Applications and Science (ATLAS, launched in 1992) and the Total Ozone Mapping Spectrometer (TOMS, launched on the Earth Probe satellite in 1996), the Agency also performs ground-based air pollution research. The ability to measure trace amounts of airborne pollutants precisely and quickly is important for determining natural patterns and human effects on global warming and air pollution, but until recent advances in field-grade spectroscopic instrumentation, this rapid, accurate data collection was limited and extremely difficult. In order to understand causes of climate change and airborne pollution, NASA has supported the development of compact, low power, rapid response instruments operating in the mid-infrared "molecular fingerprint" portion of the electromagnetic spectrum. These instruments, which measure atmospheric trace gases and airborne particles, can be deployed in mobile laboratories - customized ground vehicles, typically - to map distributions of pollutants in real time. The instruments must be rugged enough to operate rapidly and accurately, despite frequent jostling that can misalign, damage, or disconnect sensitive components. By measuring quickly while moving through an environment, a mobile laboratory can correlate data and geographic points, revealing patterns in the environment s pollutants. Rapid pollutant measurements also enable direct determination of pollutant sources and sinks (mechanisms that remove greenhouse gases and pollutants), providing information critical to understanding and managing atmospheric greenhouse gas and air pollutant concentrations.

Airborne & Ground-based measurements of atmospheric CO2 using the 1.57-μm laser absorption spectrometer

NASA Astrophysics Data System (ADS)

Sakaizawa, D.; Kawakami, S.; Nakajima, M.; Tanaka, T.; Miyamoto, Y.; Morino, I.; Uchino, O.; Asai, K.

2009-12-01

Greenhouse gases observing satellite (GOSAT) started the measurement of global CO2 abundances to reveal its continental inventory using two passive remote sensors. The goal that the sensor needs to be done is to achieve an 1% relative accuracy in order to reduce uncertainties of CO2 budget. Nevertheless, in the future global CO2 monitoring, more accurate measurement of global tropospheric CO2 abundances with the monthly regional scale are required to improve the knowledge of CO2 exchanges among the land, ocean, and atmosphere. In order to fulfill demands, a laser remote sensor, such as DIAL or laser absorption spectrometer (LAS), is a potential candidate of future space-based missions. Nowadays, those technologies are required to demonstrate an accuracy of the few-ppm level through airborne & ground-based measurements. We developed the prototype of the 1.57um LAS for a step of the next missions and perform it at the ground-based and airborne platform to show the properly validated performance in the framework of GOSAT validation. Our CO2 LAS is consisted of all optical fiber circuits & compact receiving /transmitting optics to achieve the portable, flexible and rigid system. The optical sources of on- and off-line are distributed feedback lasers, which are tuned at the strong and weak position of the R12 line in the (30012<-00001) absorption band. Their fiber coupled outputs are sinusoidal amplitude modulated by each EO devices with kHz rate and combined and amplified using an erbium doped fiber amplifier. Scattered signals from the hard target are collected by the 11cm receiving telescope and detected and stored into the laptop computer. After that, we evaluated the atmospheric CO2 density using the meteorological parameters and ratio between the on- and off-line signals. The resultant of the ground-based measurement of 3km optical length indicated that the statistical error of the path averaged atmospheric CO2 density is less than 2.8ppm with 25 minutes averaging

Airborne bacteria in the atmosphere: Presence, purpose, and potential

NASA Astrophysics Data System (ADS)

Smets, Wenke; Moretti, Serena; Denys, Siegfried; Lebeer, Sarah

2016-08-01

Numerous recent studies have highlighted that the types of bacteria present in the atmosphere often show predictable patterns across space and time. These patterns can be driven by differences in bacterial sources of the atmosphere and a wide range of environmental factors, including UV intensity, precipitation events, and humidity. The abundance of certain bacterial taxa is of interest, not only for their ability to mediate a range of chemical and physical processes in the atmosphere, such as cloud formation and ice nucleation, but also for their implications -both beneficial and detrimental-for human health. Consequently, the widespread importance of airborne bacteria has stimulated the search for their applicability. Improving air quality, modelling the dispersal of airborne bacteria (e.g. pathogens) and biotechnological purposes are already being explored. Nevertheless, many technological challenges still need to be overcome to fully understand the roles of airborne bacteria in our health and global ecosystems.

Lidar Measurements of Atmospheric CO2 From Regional to Global Scales

NASA Technical Reports Server (NTRS)

Lin, Bing; Harrison, F. Wallace; Nehrir, Amin; Browell, Edward; Dobler, Jeremy; Campbell, Joel; Meadows, Byron; Obland, Michael; Ismail, Syed; Kooi, Susan;

Retrieval of profile information from airborne multiaxis UV-visible skylight absorption measurements.

PubMed

Bruns, Marco; Buehler, Stefan A; Burrows, John P; Heue, Klaus-Peter; Platt, Ulrich; Pundt, Irene; Richter, Andreas; Rozanov, Alexej; Wagner, Thomas; Wang, Ping

2004-08-01

A recent development in ground-based remote sensing of atmospheric constituents by UV-visible absorption measurements of scattered light is the simultaneous use of several horizon viewing directions in addition to the traditional zenith-sky pointing. The different light paths through the atmosphere enable the vertical distribution of some atmospheric absorbers, such as NO2, BrO, or O3, to be retrieved. This approach has recently been implemented on an airborne platform. This novel instrument, the airborne multiaxis differential optical absorption spectrometer (AMAXDOAS), has been flown for the first time. In this study, the amount of profile information that can be retrieved from such measurements is investigated for the trace gas NO2. Sensitivity studies on synthetic data are performed for a variety of representative measurement conditions including two wavelengths, one in the UV and one in the visible, two different surface spectral reflectances, various lines of sight (LOSs), and for two different flight altitudes. The results demonstrate that the AMAXDOAS measurements contain useful profile information, mainly at flight altitude and below the aircraft. Depending on wavelength and LOS used, the vertical resolution of the retrieved profiles is as good as 2 km near flight altitude. Above 14 km the profile information content of AMAXDOAS measurements is sparse. Airborne multiaxis measurements are thus a promising tool for atmospheric studies in the troposphere and the upper troposphere and lower stratosphere region.

New Atmospheric Observations from the Airborne GNSS Instrument System for Multistatic and Occultation Sensing (GISMOS)

NASA Astrophysics Data System (ADS)

Haase, J. S.; Xie, F.; Muradyan, P.; Garrison, J. L.; Lulich, T.; Voo, J.; Larson, K. M.

2008-12-01

The Airborne GNSS Instrument System for Multistatic and Occultation Sensing (GISMOS) was deployed on the NCAR HIAPER (High-performance Instrumented Airborne Platform for Environmental Research) aircraft to make atmospheric observations over the Gulf of Mexico coastal region in February 2008. The objective of the measurements was to test the performance of the system in comparisons with radiosonde profiles and dropsonde profiles that were also collected during the field campaign. The airborne GNSS radio occultation measures of GNSS signals from satellites that are setting or rising behind the Earth's limb relative to the receiver on board an aircraft. High-gain side-looking antennas and a 10MHz GPS Recording System that records the raw RF signal make this set of instrumentation unique, and especially adapted for open-loop tracking observations in the lower atmosphere. Measurements of the amount of refraction in the signal ray paths are inverted using an Abel transform procedure to retrieve a profile of refractivity, which depends on atmospheric pressure, temperature and relative humidity. The airborne geometry, in contrast to the space- borne satellite occultation geometry, is affected by a large drift in the tangent point location, that is the location of the closest point to the Earth surface, as the ray path descends in the atmosphere. Therefore plans for the validation campaign included releasing dropsondes in the plane of the line of sight of the satellite-receiver occultation geometry in order to study this effect. Careful timing and location of the flight path was used to coordinate occultation times with operational and supplementary radiosonde launches. A total of 6 days of balloon sounding data were collected with 20 dropsondes and 28 supplementary radiosonde profiles. A discussion of the technical performance of the system will be presented, which describes the signal characteristics and antenna performance. Preliminary results on the quality of retrieved

Pulsed Airborne Lidar Measurements of Atmospheric CO2 Column Absorption and Line Shapes from 3-13 km Altitudes

NASA Technical Reports Server (NTRS)

Abshire, J. B.; Riris, H.; Allan, G. R.; Weaver, C.; Hasselbrack, W.; Sun, X.

2009-01-01

We have developed a lidar technique for measuring the tropospheric C02 concentrations as a candidate for NASA's planned ASCENDS mission. Our technique uses two pulsed laser transmitters allowing simultaneous measurement of a C02 absorption line in the 1570 nm band, 02 extinction in the Oxygen A-band and surface height and backscatter. The lidar measures the energy and time of flight of the laser echoes reflected from the atmosphere and surface. The lasers are stepped in wavelength across the C02 line and an 02 line region during the measurement. The receiver uses a telescope and photon counting detectors, and measures the background light and energies of the laser echoes from the surface along with scattering from any aerosols in the path. The gas extinction and column densities for the C02 and 02 gases are estimated from the ratio of the on- and off- line signals via the DIAL technique. Time gating is used to isolate the laser echo signals from the surface, and to reject laser photons scattered in the atmosphere. We have developed an airborne lidar to demonstrate the C02 measurement from the NASA Glenn Lear 25 aircraft. The airborne lidar steps the pulsed laser's wavelength across a selected C02 line with 20 steps per scan. The line scan rate is 450 Hz and laser pulse widths are I usec. The time resolved laser backscatter is collected by a 20 cm telescope, detected by a photomultiplier and is recorded by a photon counting system. We made initial airborne measurements on flights during October and December 2008. Laser backscatter and absorption measurements were made over a variety of land and water surfaces and through thin and broken clouds. Atmospheric C02 column measurements using the 1571.4, 1572.02 and 1572.33 nm C02 lines. Two flights were made above the DOE SGP ARM site at altitudes from 3-8 km. These nights were coordinated with DOE investigators who Hew an in-situ C02 sensor on a Cessna aircraft under the path. The increasing C02 line absorptions with

Evaluation of meteorological airborne Doppler radar

NASA Technical Reports Server (NTRS)

Hildebrand, P. H.; Mueller, C. K.

1984-01-01

This paper will discuss the capabilities of airborne Doppler radar for atmospheric sciences research. The evaluation is based on airborne and ground based Doppler radar observations of convective storms. The capability of airborne Doppler radar to measure horizontal and vertical air motions is evaluated. Airborne Doppler radar is shown to be a viable tool for atmospheric sciences research.

AIRBORNE BACTERIA IN THE ATMOSPHERIC SURFACE LAYER: TEMPORAL DISTRIBUTION ABOVE A GRASS SEED FIELD

EPA Science Inventory

Temporal airborne bacterial concentrations and meteorological conditions were measured above a grass seed field in the Willamette River Valley, near Corvallis, Oregon, in the summer of 1993. he report describes the changes in the atmospheric surface layer over a grass seed field ...

Double-pulse 2-μm integrated path differential absorption lidar airborne validation for atmospheric carbon dioxide measurement.

PubMed

Refaat, Tamer F; Singh, Upendra N; Yu, Jirong; Petros, Mulugeta; Remus, Ruben; Ismail, Syed

2016-05-20

Field experiments were conducted to test and evaluate the initial atmospheric carbon dioxide (CO₂) measurement capability of airborne, high-energy, double-pulsed, 2-μm integrated path differential absorption (IPDA) lidar. This IPDA was designed, integrated, and operated at the NASA Langley Research Center on-board the NASA B-200 aircraft. The IPDA was tuned to the CO₂ strong absorption line at 2050.9670 nm, which is the optimum for lower tropospheric weighted column measurements. Flights were conducted over land and ocean under different conditions. The first validation experiments of the IPDA for atmospheric CO₂ remote sensing, focusing on low surface reflectivity oceanic surface returns during full day background conditions, are presented. In these experiments, the IPDA measurements were validated by comparison to airborne flask air-sampling measurements conducted by the NOAA Earth System Research Laboratory. IPDA performance modeling was conducted to evaluate measurement sensitivity and bias errors. The IPDA signals and their variation with altitude compare well with predicted model results. In addition, off-off-line testing was conducted, with fixed instrument settings, to evaluate the IPDA systematic and random errors. Analysis shows an altitude-independent differential optical depth offset of 0.0769. Optical depth measurement uncertainty of 0.0918 compares well with the predicted value of 0.0761. IPDA CO₂ column measurement compares well with model-driven, near-simultaneous air-sampling measurements from the NOAA aircraft at different altitudes. With a 10-s shot average, CO₂ differential optical depth measurement of 1.0054±0.0103 was retrieved from a 6-km altitude and a 4-GHz on-line operation. As compared to CO₂ weighted-average column dry-air volume mixing ratio of 404.08 ppm, derived from air sampling, IPDA measurement resulted in a value of 405.22±4.15  ppm with 1.02% uncertainty and

Pulsed Airborne Lidar Measurements of C02 Column Absorption

NASA Technical Reports Server (NTRS)

Abshire, James B.; Riris, Haris; Allan, Graham R.; Weaver, Clark J.; Mao, Jianping; Sun, Xiaoli; Hasselbrack, William E.; Rodriquez, Michael; Browell, Edward V.

2011-01-01

We report on airborne lidar measurements of atmospheric CO2 column density for an approach being developed as a candidate for NASA's ASCENDS mission. It uses a pulsed dual-wavelength lidar measurement based on the integrated path differential absorption (IPDA) technique. We demonstrated the approach using the CO2 measurement from aircraft in July and August 2009 over four locations. The results show clear CO2 line shape and absorption signals, which follow the expected changes with aircraft altitude from 3 to 13 km. The 2009 measurements have been analyzed in detail and the results show approx.1 ppm random errors for 8-10 km altitudes and approx.30 sec averaging times. Airborne measurements were also made in 2010 with stronger signals and initial analysis shows approx. 0.3 ppm random errors for 80 sec averaging times for measurements at altitudes> 6 km.

Pulsed Airborne Lidar Measurements of Atmospheric CO2 Column Absorption and Line Shapes from 3-13 km Altitudes

NASA Technical Reports Server (NTRS)

Abshire, James; Riris, Haris; Allan, Graham; Weaver, Clark; Mao, Jianping; Sun, Xiaoli; Hasselbrack, William

2010-01-01

We have developed a pulsed lidar technique for measuring the tropospheric CO2 concentrations as a candidate for NASA's planned ASCENDS space mission. Our technique uses two pulsed laser transmitters allowing simultaneous measurement of a CO2 absorption line in the 1570 nm band, O2 extinction in the Oxygen A-band and surface height and backscatter. The lidar measures the energy and time of flight of the laser echoes reflected from the atmosphere and surface. The lasers are rapidly and precisely stepped in wavelength across the CO2 line and an O2 line region during the measurement. The direct detection receiver uses a telescope and photon counting detectors, and measures the background light and energies of the laser echoes from the surface along with scattering from any aerosols in the path. The gas extinction and column densities for the CO2 and O2 gases are estimated from the ratio of the on- and off- line signals via the DIAL technique. Time gating is used to isolate the laser echo signals from the surface, and to reject laser photons scattered in the atmosphere. The time of flight of the laser pulses are also used to estimate the height of the scattering surface and to identify cases of mixed cloud and ground scattering. We have developed an airborne lidar to demonstrate the CO2 measurement from the NASA Glenn Lear-25 aircraft. The airborne lidar steps the pulsed laser's wavelength across the selected CO2 line with 20 steps per scan. The line scan rate is 450 Hz, the laser pulse widths are 1 usec, and laser pulse energy is 24 uJ. The time resolved laser backscatter is collected by a 20 cm telescope, detected by a photomultiplier and is recorded by a photon counting system. We made initial airborne measurements on flights during fall 2008. Laser backscatter and absorption measurements were made over a variety of land and water surfaces and through thin clouds. The atmospheric CO2 column measurements using the 1572.33 nm CO2 lines. Two flights were made above the

A Study of Reflected Sonic Booms Using Airborne Measurements

NASA Technical Reports Server (NTRS)

Kantor, Samuel R.; Cliatt, Larry J., II

2017-01-01

In support of ongoing efforts to bring commercial supersonic flight to the public, the Sonic Booms in Atmospheric Turbulence (SonicBAT) flight test was conducted at NASA Armstrong Flight Research Center. During this test, airborne sonic boom measurements were made using an instrumented TG-14 motor glider, called the Airborne Acoustic Measurement Platform (AAMP).During the flight program, the AAMP was consistently able to measure the sonic boom wave that was reflected off of the ground, in addition to the incident wave, resulting in the creation of a completely unique data set of airborne sonic boom reflection measurements. This paper focuses on using this unique data set to investigate the ability of sonic boom modeling software to calculate sonic boom reflections. Because the algorithms used to model sonic boom reflections are also used to model the secondary carpet and over the top booms, the use of actual flight data is vital to improving the understanding of the effects of sonic booms outside of the primary carpet. Understanding these effects becomes especially important as the return of commercial supersonic approaches, as well as ensuring the accuracy of mission planning for future experiments.

Do airborne microbes matter for atmospheric chemistry and cloud formation?

PubMed

Konstantinidis, Konstantinos T

2014-06-01

The role of airborne microbial cells in the chemistry of the atmosphere and cloud formation remains essentially speculative. Recent studies have indicated that microbes might be more important than previously anticipated for atmospheric processes. However, more work and direct communication between microbiologists and atmospheric scientists and modellers are necessary to better understand and model bioaerosol-cloud-precipitation-climate interactions. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

Atmospheric Transport Studies Using In-situ Airborne Gas Chromatograph Measurements: An Overview of the NOAA Climate Monitoring and Diagnostics Laboratory (CMDL) Contribution.

NASA Astrophysics Data System (ADS)

Moore, F.; Dutton, G.; Elkins, J.; Hall, B.; Hurst, D.; Nance, D.; Ray, E.; Romashkin, P.; Thompson, T.; Volk, C. M.

2005-12-01

Accurate models of atmospheric transport are crucial to our current understanding of ozone production/loss and its coupling with climate change. Over the last ``20 years'', improvements in the ability to predict ``The Antarctic Ozone Hole and Polar Ozone Loss'' have tracked improvements in transport models. Data taken from the NOAA/CMDL airborne in-situ GC's (ACATS, LACE, PANTHER, and UCATS) have and will continue to play key roles in quantifying many aspects of stratospheric transport. Our data have been used in many of the model assessments to date. We will display an overview of the transport issues studied over the years using our data. They include descent with mixing within and into the polar vortex, entrainment of mid-latitude air across the vortex edge, upwelling and entrainment in the tropical pipe, isentropic transport across the tropopause into the lowermost stratosphere, mean ages of air parcels in the stratosphere, and stratospheric path distributions. ACATS - Airborne Chromatograph for Atmospheric Trace Species LACE - Lightweight Airborne Chromatograph Experiment PANTHER - PAN and Other Trace Hydrohalocarbons ExpeRiment UCATS - Unmanned aerial systems Chromatograph for Atmospheric Trace Species

Applications of airborne remote sensing in atmospheric sciences research

NASA Technical Reports Server (NTRS)

Serafin, R. J.; Szejwach, G.; Phillips, B. B.

1984-01-01

This paper explores the potential for airborne remote sensing for atmospheric sciences research. Passive and active techniques from the microwave to visible bands are discussed. It is concluded that technology has progressed sufficiently in several areas that the time is right to develop and operate new remote sensing instruments for use by the community of atmospheric scientists as general purpose tools. Promising candidates include Doppler radar and lidar, infrared short range radiometry, and microwave radiometry.

Airborne laser systems for atmospheric sounding in the near infrared

NASA Astrophysics Data System (ADS)

Sabatini, Roberto; Richardson, Mark A.; Jia, Huamin; Zammit-Mangion, David

2012-06-01

This paper presents new techniques for atmospheric sounding using Near Infrared (NIR) laser sources, direct detection electro-optics and passive infrared imaging systems. These techniques allow a direct determination of atmospheric extinction and, through the adoption of suitable inversion algorithms, the indirect measurement of some important natural and man-made atmospheric constituents, including Carbon Dioxide (CO2). The proposed techniques are suitable for remote sensing missions performed by using aircraft, satellites, Unmanned Aerial Vehicles (UAV), parachute/gliding vehicles, Roving Surface Vehicles (RSV), or Permanent Surface Installations (PSI). The various techniques proposed offer relative advantages in different scenarios. All are based on measurements of the laser energy/power incident on target surfaces of known geometric and reflective characteristics, by means of infrared detectors and/or infrared cameras calibrated for radiance. Experimental results are presented relative to ground and flight trials performed with laser systems operating in the near infrared (NIR) at λ = 1064 nm and λ = 1550 nm. This includes ground tests performed with 10 Hz and 20 KHz PRF NIR laser systems in a variety of atmospheric conditions, and flight trials performed with a 10 Hz airborne NIR laser system installed on a TORNADO aircraft, flying up to altitudes of 22,000 ft above ground level. Future activities are planned to validate the atmospheric retrieval algorithms developed for CO2 column density measurements, with emphasis on aircraft related emissions at airports and other high air-traffic density environments.

Column Closure Studies of Lower Tropospheric Aerosol and Water Vapor During ACE-Asia Using Airborne Sunphotometer, Airborne In-Situ and Ship-Based Lidar Measurements

NASA Technical Reports Server (NTRS)

Schmid, B.; Hegg, A.; Wang, J.; Bates, D.; Redemann, J.; Russells, P. B.; Livingston, J. M.; Jonsson, H. H.; Welton, E. J.; Seinfield, J. H.

2003-01-01

We assess the consistency (closure) between solar beam attenuation by aerosols and water vapor measured by airborne sunphotometry and derived from airborne in-situ, and ship-based lidar measurements during the April 2001 Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia). The airborne data presented here were obtained aboard the Twin Otter aircraft. Comparing aerosol extinction o(550 nm) from four different techniques shows good agreement for the vertical distribution of aerosol layers. However, the level of agreement in absolute magnitude of the derived aerosol extinction varied among the aerosol layers sampled. The sigma(550 nm) computed from airborne in-situ size distribution and composition measurements shows good agreement with airborne sunphotometry in the marine boundary layer but is considerably lower in layers dominated by dust if the particles are assumed to be spherical. The sigma(550 nm) from airborne in-situ scattering and absorption measurements are about approx. 13% lower than those obtained from airborne sunphotometry during 14 vertical profiles. Combining lidar and the airborne sunphotometer measurements reveals the prevalence of dust layers at altitudes up to 10 km with layer aerosol optical depth (from 3.5 to 10 km altitude) of approx. 0.1 to 0.2 (500 nm) and extinction-to-backscatter ratios of 59-71 sr (523 nm). The airborne sunphotometer aboard the Twin Otter reveals a relatively dry atmosphere during ACE- Asia with all water vapor columns less than 1.5 cm and water vapor densities w less than 12 g/cu m. Comparing layer water vapor amounts and w from the airborne sunphotometer to the same quantities measured with aircraft in-situ sensors leads to a high correlation (r(sup 3)=0.96) but the sunphotometer tends to underestimate w by 7%.

Airborne Lidar measurements of Atmospheric CO2 Column Absorption and Line Shapes from 3-11 km altitudes

NASA Astrophysics Data System (ADS)

Abshire, J. B.; Riris, H.; Allan, G. R.; Weaver, C.; Mao, J.; Hasselbrack, W.

2009-04-01

accommodation study. During 2008 we reconfigured our lidar for airborne use and made measurements of atmospheric CO2 absorption in the nadir column from the aircraft to the surface during 5 flights. The airborne lidar sweeps the laser wavelength across the CO2 line in either 10 or 20 steps per measurement. The line scan rate is ~ 1 KHz and the laser pulse widths are 1 usec. The time resolved laser backscatter is collected by the telescope and detected by a photomultiplier and recorded by a photon counting timing system. We installed our lidar on the NASA Glenn Lear-25 aircraft in October and first made measurements using the 1571.4 nm CO2 absorption line while flying in northern Ohio. We made laser backscatter and absorption measurements over a variety of land surface types, water surfaces and through thin clouds, broken clouds and to cloud tops. Strong laser signals were observed at altitudes from 2.5 to 11 km on two flights. We completed three additional flights during December 2008 and gathered over 6 hours of atmospheric CO2 column measurements using the 1572.02 and 1572.33 nm CO2 lines. Airborne CO2 line shape and absorption measurements were made while flying at 3-11 km altitudes over southwestern Ohio. Subsequently two flights were made from Ponca City OK, just east of the US Department of Energy's (DOE) ARM site. We made 4 hours of airborne measurements in square patterns around the ARM site at altitudes from 3-8 km. The increased CO2 line absorptions at higher altitudes were evident in all flights. The December flights were also coordinated with DOE investigators who flew an in-situ CO2 sensor on a Cessna aircraft inside the CO2 sounder's flight pattern. These yielded two height resolved profiles of CO2 concentrations from 5 km to the surface, which are being analyzed with radiosonde measurements for comparisons. More details of the flights, measurements and their analysis will be described in the presentation.

Constraints on Southern Ocean CO2 Fluxes and Seasonality from Atmospheric Vertical Gradients Observed on Multiple Airborne Campaigns

NASA Astrophysics Data System (ADS)

McKain, K.; Sweeney, C.; Stephens, B. B.; Long, M. C.; Jacobson, A. R.; Basu, S.; Chatterjee, A.; Weir, B.; Wofsy, S. C.; Atlas, E. L.; Blake, D. R.; Montzka, S. A.; Stern, R.

2017-12-01

The Southern Ocean plays an important role in the global carbon cycle and climate system, but net CO2 flux into the Southern Ocean is difficult to measure and model because it results from large opposing and seasonally-varying fluxes due to thermal forcing, biological uptake, and deep-water mixing. We present an analysis to constrain the seasonal cycle of net CO2 exchange with the Southern Ocean, and the magnitude of summer uptake, using the vertical gradients in atmospheric CO2 observed during three aircraft campaigns in the southern polar region. The O2/N2 Ratio and CO2 Airborne Southern Ocean Study (ORCAS) was an airborne campaign that intensively sampled the atmosphere at 0-13 km altitude and 45-75 degrees south latitude in the austral summer (January-February) of 2016. The global airborne campaigns, the HIAPER Pole-to-Pole Observations (HIPPO) study and the Atmospheric Tomography Mission (ATom), provide additional measurements over the Southern Ocean from other seasons and multiple years (2009-2011, 2016-2017). Derivation of fluxes from measured vertical gradients requires robust estimates of the residence time of air in the polar tropospheric domain, and of the contribution of long-range transport from northern latitudes outside the domain to the CO2 gradient. We use diverse independent approaches to estimate both terms, including simulations using multiple transport and flux models, and observed gradients of shorter-lived tracers with specific sources regions and well-known loss processes. This study demonstrates the utility of aircraft profile measurements for constraining large-scale air-sea fluxes for the Southern Ocean, in contrast to those derived from the extrapolation of sparse ocean and atmospheric measurements and uncertain flux parameterizations.

The Airborne Measurements of Methane Fluxes (AIRMETH) Arctic Campaign (Invited)

NASA Astrophysics Data System (ADS)

Serafimovich, A.; Metzger, S.; Hartmann, J.; Kohnert, K.; Sachs, T.

2013-12-01

One of the most pressing questions with regard to climate feedback processes in a warming Arctic is the regional-scale methane release from Arctic permafrost areas. The Airborne Measurements of Methane Fluxes (AIRMETH) campaign is designed to quantitatively and spatially explicitly address this question. Ground-based eddy covariance (EC) measurements provide continuous in-situ observations of the surface-atmosphere exchange of methane. However, these observations are rare in the Arctic permafrost zone and site selection is bound by logistical constraints among others. Consequently, these observations cover only small areas that are not necessarily representative of the region of interest. Airborne measurements can overcome this limitation by covering distances of hundreds of kilometers over time periods of a few hours. Here, we present the potential of environmental response functions (ERFs) for quantitatively linking methane flux observations in the atmospheric surface layer to meteorological and biophysical drivers in the flux footprints. For this purpose thousands of kilometers of AIRMETH data across the Alaskan North Slope are utilized, with the aim to extrapolate the airborne EC methane flux observations to the entire North Slope. The data were collected aboard the research aircraft POLAR 5, using its turbulence nose boom and fast response methane and meteorological sensors. After thorough data pre-processing, Reynolds averaging is used to derive spatially integrated fluxes. To increase spatial resolution and to derive ERFs, we then use wavelet transforms of the original high-frequency data. This enables much improved spatial discretization of the flux observations, and the quantification of continuous and biophysically relevant land cover properties in the flux footprint of each observation. A machine learning technique is then employed to extract and quantify the functional relationships between the methane flux observations and the meteorological and

High Energy 2-Micron Solid-State Laser Transmitter for NASA's Airborne CO2 Measurements

NASA Technical Reports Server (NTRS)

Singh, Upendra N.; Yu, Jirong; Petros, Mulugeta; Bai, Yingxin

2012-01-01

A 2-micron pulsed, Integrated Path Differential Absorption (IPDA) lidar instrument for ground and airborne atmospheric CO2 concentration measurements via direct detection method is being developed at NASA Langley Research Center. This instrument will provide an alternate approach to measure atmospheric CO2 concentrations with significant advantages. A high energy pulsed approach provides high-precision measurement capability by having high signal-to-noise level and unambiguously eliminates the contamination from aerosols and clouds that can bias the IPDA measurement.

ATLAS: Airborne Tunable Laser Absorption Spectrometer for stratospheric trace gas measurements

NASA Technical Reports Server (NTRS)

Loewenstein, Max; Podolske, James R.; Strahan, Susan E.

1990-01-01

The ATLAS instrument is an advanced technology diode laser based absorption spectrometer designed specifically for stratospheric tracer studies. This technique was used in the acquisition of N2O tracer data sets on the Airborne Antarctic Ozone Experiment and the Airborne Arctic Stratospheric Expedition. These data sets have proved valuable for comparison with atmospheric models, as well as in assisting in the interpretation of the entire ensemble of chemical and meteorological data acquired on these two field studies. The N2O dynamical tracer data set analysis revealed several ramifications concerning the polar atmosphere: the N2O/NO(y) correlation, which is used as a tool to study denitrification in the polar vertex; the N2O Southern Hemisphere morphology, showing subsidence in the winter polar vortex; and the value of the N2O measurements in the interpretation of ClO, O3, and NO(y) measurements and of the derived dynamical tracer, potential vorticity. Field studies also led to improved characterization of the instrument and to improved accuracy.

Ground and Airborne Methane Measurements with an Optical Parametric Amplifier

NASA Technical Reports Server (NTRS)

Numata, Kenji

2012-01-01

We report on ground and airborne atmospheric methane measurements with a differential absorption lidar using an optical parametric amplifier (OPA). Methane is a strong greenhouse gas on Earth and its accurate global mapping is urgently needed to understand climate change. We are developing a nanosecond-pulsed OPA for remote measurements of methane from an Earth-orbiting satellite. We have successfully demonstrated the detection of methane on the ground and from an airplane at approximately 11-km altitude.

Airborne direct-detection and coherent wind lidar measurements over the North Atlantic in 2015 supporting ESA's aeolus mission

NASA Astrophysics Data System (ADS)

Marksteiner, Uwe; Reitebuch, Oliver; Lemmerz, Christian; Lux, Oliver; Rahm, Stephan; Witschas, Benjamin; Schäfler, Andreas; Emmitt, Dave; Greco, Steve; Kavaya, Michael J.; Gentry, Bruce; Neely, Ryan R.; Kendall, Emma; Schüttemeyer, Dirk

2018-04-01

The launch of the Aeolus mission by the European Space Agency (ESA) is planned for 2018. The satellite will carry the first wind lidar in space, ALADIN (Atmospheric Laser Doppler INstrument). Its prototype instrument, the ALADIN Airborne Demonstrator (A2D), was deployed during several airborne campaigns aiming at the validation of the measurement principle and optimization of algorithms. In 2015, flights of two aircraft from DLR & NASA provided the chance to compare parallel wind measurements from four airborne wind lidars for the first time.

Microbiology and atmospheric processes: research challenges concerning the impact of airborne micro-organisms on the atmosphere and climate

NASA Astrophysics Data System (ADS)

Morris, C. E.; Sands, D. C.; Bardin, M.; Jaenicke, R.; Vogel, B.; Leyronas, C.; Ariya, P. A.; Psenner, R.

2011-01-01

For the past 200 years, the field of aerobiology has explored the abundance, diversity, survival and transport of micro-organisms in the atmosphere. Micro-organisms have been explored as passive and severely stressed riders of atmospheric transport systems. Recently, an interest in the active roles of these micro-organisms has emerged along with proposals that the atmosphere is a global biome for microbial metabolic activity and perhaps even multiplication. As part of a series of papers on the sources, distribution and roles in atmospheric processes of biological particles in the atmosphere, here we describe the pertinence of questions relating to the potential roles that air-borne micro-organisms might play in meteorological phenomena. For the upcoming era of research on the role of air-borne micro-organisms in meteorological phenomena, one important challenge is to go beyond descriptions of abundance of micro-organisms in the atmosphere toward an understanding of their dynamics in terms of both biological and physico-chemical properties and of the relevant transport processes at different scales. Another challenge is to develop this understanding under contexts pertinent to their potential role in processes related to atmospheric chemistry, the formation of clouds, precipitation and radiative forcing. This will require truly interdisciplinary approaches involving collaborators from the biological and physical sciences, from disciplines as disparate as agronomy, microbial genetics and atmosphere physics, for example.

ACME-V mission in the North Slope of Alaska (Airborne Carbon MEasurements)

NASA Astrophysics Data System (ADS)

Biraud, S.; Torn, M. S.; Sedlacek, A. J., III; Sweeney, C.; Springston, S. R.

2016-12-01

Atmospheric temperatures are warming faster in the Arctic than predicted by climate models. The impact of this warming on permafrost degradation is not well understood, but it is projected to increase carbon decomposition and greenhouse gas production (CO2 and/or CH4) by arctic ecosystems. Airborne observations of atmospheric trace gases, aerosols and cloud properties in North Slopes of Alaska (NSA) are improving our understanding of global climate, with the goal of reducing the uncertainty in global and regional climate simulations and projections. From June 1 through September 15, 2015, the Atmospheric radiation measurement (ARM) airborne facility (AAF) deployed a G1 research aircraft (ARM-ACME-V mission) to fly over the North Slope of Alaska, with occasional vertical profiling to measure trace gas concentrations, between Prudhoe Bay, Oliktok point, Barrow, Atqasuk, Ivotuk, and Toolik Lake. The aircraft payload includes a Picarro and a LGR analyzers for continuous measurements of CO2, CH4, H2O, and CO and N2O mixing ratios, and a 12-flask sampler for analysis of carbon cycle gases (CO2, CO, CH4, N2O, 13CO2, 14CO2, carbonyl sulfide, and trace hydrocarbon species including ethane). The aircraft payload also include measurements of aerosol properties (number size distribution, total number concentration, absorption, and scattering), cloud properties (droplet and ice size information), atmospheric thermodynamic state, and solar/infrared radiation. Preliminary results using CO2, CH4, CO, ethane, and soot spectroscopy observations are used to tease apart biogenic and thermogenic (biomass burning, and oil and gas production) contributions.

Study of cloud properties using airborne and satellite measurements

NASA Astrophysics Data System (ADS)

Boscornea, Andreea; Stefan, Sabina; Vajaiac, Sorin Nicolae

2014-08-01

The present study investigates cloud microphysics properties using aircraft and satellite measurements. Cloud properties were drawn from data acquired both from in situ measurements with state of the art airborne instrumentation and from satellite products of the MODIS06 System. The used aircraft was ATMOSLAB - Airborne Laboratory for Environmental Atmospheric Research, property of the National Institute for Aerospace Research "Elie Carafoli" (INCAS), Bucharest, Romania, which is specially equipped for this kind of research. The main tool of the airborne laboratory is a Cloud, Aerosol and Precipitation Spectrometer - CAPS (30 bins, 0.51- 50 μm). The data was recorded during two flights during the winter 2013-2014, over a flat region in the south-eastern part of Romania (between Bucharest and Constanta). The analysis of cloud particle size variations and cloud liquid water content provided by CAPS can explain cloud processes, and can also indicate the extent of aerosols effects on clouds. The results, such as cloud coverage and/or cloud types, microphysical parameters of aerosols on the one side and the cloud microphysics parameters obtained from aircraft flights on the other side, was used to illustrate the importance of microphysics cloud properties for including the radiative effects of clouds in the regional climate models.

Analysis of Pulsed Airborne Lidar Measurements of Atmospheric CO2 Column Absorption from 3-13 km Altitudes

NASA Technical Reports Server (NTRS)

Abshire, James B.; Weaver, Clark J.; Riris, Haris; Mao, Jianping; Sun, Xiaoli; Allan, Graham R.; Hasselbrack, William; Browell, Edward V.

2011-01-01

We have developed a pulsed lidar technique for measuring the tropospheric CO2 concentrations as a candidate for NASA's ASCENDS space mission [1]. It uses two pulsed laser transmitters allowing simultaneous measurement of a CO2 absorption line in the 1575 nm band, O2 extinction in the Oxygen A-band, surface height and backscatter profile. The lasers are precisely stepped in wavelength across the CO2 line and an O2 line region during the measurement. The direct detection receiver measures the energies of the laser echoes from the surface along with the range profile of scattering in the path. The column densities for the CO2 and O2 gases are estimated from the ratio of the on- and off-line signals via the integrated path differential absorption (IPDA) technique. The time of flight of the laser pulses is used to estimate the height of the scattering surface and to reject laser photons scattered in the atmosphere. We developed an airborne lidar to demonstrate an early version of the CO2 measurement from the NASA Glenn Lear-25 aircraft. The airborne lidar stepped the pulsed laser's wavelength across the selected CO2 line with 20 wavelength steps per scan. The line scan rate is 450 Hz, the laser pulse widths are 1 usec, and laser pulse energy is 24 uJ. The time resolved laser backscatter is collected by a 20 cm telescope, detected by a NIR photomultiplier and is recorded on every other reading by a photon counting system [2]. During August 2009 we made a series of 2.5 hour long flights and measured the atmospheric CO2 absorption and line shapes using the 1572.33 nm CO2 line. Measurements were made at stepped altitudes from 3-13 km over locations in the US, including the SGP ARM site in Oklahoma, central Illinois, north-eastern North Carolina, and over the Chesapeake Bay and the eastern shore of Virginia. Although the received signal energies were weaker than expected for ASCENDS, clear CO2 line shapes were observed at all altitudes, and some measurements were made

Improvement of an Acoustic Sounder Device Used to Measure Atmospheric Turbulence

DTIC Science & Technology

2004-12-01

The reference standard for measuring optical turbulence is to use microthermal probe sensors. This direct measure of CT2 uses the difference in...implement, the fragility of the wires makes microthermal probes unsuitable for atmospheric characterization. Rain and airborne debris quickly break the

Lidar measurements of polar stratospheric clouds during the 1989 airborne Arctic stratospheric expedition

NASA Technical Reports Server (NTRS)

Ismail, Syed; Browell, Edward V.

1991-01-01

The Airborne Arctic Stratospheric Expedition (AASE) was conducted during January to February 1989 from the Sola Air Station, Norway. As part of this expedition, the NASA Langley Research Center's multiwavelength airborne lidar system was flown on the NASA Ames Research Center's DC-8 aircraft to measure ozone (O3) and aerosol profiles in the region of the polar vortex. The lidar system simultaneously transmitted laser beams at 1064, 603, 311, and 301.5 nm to measure atmospheric scattering, polarization and O3 profiles. Long range flights were made between Stavanger, Norway, and the North Pole, and between 40 deg W and 20 deg E meridians. Eleven flights were made, each flight lasting an average of 10 hours covering about 8000 km. Atmospheric scattering ratios, aerosol polarizations, and aerosol scattering ratio wavelength dependences were derived from the lidar measurements to altitudes above 27 km. The details of the aerosol scattering properties of lidar observations in the IR, VIS, and UV regions are presented along with correlations with the national meteorological Center's temperature profiles.

Tunable laser heterodyne spectrometer measurements of atmospheric species

NASA Technical Reports Server (NTRS)

Allario, F.; Katzberg, S. J.; Hoell, J. M.

1983-01-01

It is pointed out that spectroscopic measurements conducted with the aid of tunable laser heterodyne spectrometers in the 3-30 micron range of the electromagnetic spectrum have the potential to measure the vertical profiles of tenuous gas molecules in the atmosphere with ultra high spectral resolution and great sensitivity. Programs related to the realization of this potential have been conducted for some time, and a Laser Heterodyne Spectrometer (LHS) experiment was developed. The present investigation has the objective to provide an overview of the LHS concept for measuring the vertical profiles of tenuous gas molecules in the upper atmosphere from space and airborne platforms, and to discuss the sensitivity ranges for this technique.

Pulsed Lidar Measurements of Atmospheric CO2 Column Concentration in the ASCENDS 2014 Airborne Campaign

NASA Astrophysics Data System (ADS)

Abshire, J. B.; Ramanathan, A. K.; Mao, J.; Riris, H.; Allan, G. R.; Hasselbrack, W. E.; Chen, J. R.

2015-12-01

We report progress in demonstrating a pulsed, wavelength-resolved IPDA lidar technique for measuring the tropospheric CO2 concentrations as a candidate for NASA's ASCENDS mission. The CO2 lidar flies on NASA's DC-8 aircraft and measures the atmospheric backscatter profiles and shape of the 1572.33 nm absorption line by using 30 wavelength samples distributed across the lube. Our post-flight analysis estimates the lidar range and pulse energies at each wavelength 10 times per second. The retrievals solve for the optimum CO2 absorption line shape and the column average CO2 concentrations using radiative transfer calculations based on HITRAN, the aircraft altitude, range to the scattering surface, and the atmospheric conditions. We compare these to CO2 concentrations sampled by in-situ sensors on the aircraft. The number of wavelength samples can be reduced in the retrievals. During the ASCENDS airborne campaign in 2013 two flights were made in February over snow in the Rocky Mountains and the Central Plains allowing measurement of snow-covered surface reflectivity. Several improvements were made to the lidar for the 2014 campaign. These included using a new step-locked laser diode source, and incorporating a new HgCdTe APD detector and analog digitizer into the lidar receiver. Testing showed this detector had higher sensitivity, analog response, and a more linear dynamic range than the PMT detector used previously. In 2014 flights were made in late August and early September over the California Central Valley, the redwood forests along the California coast, two desert areas in Nevada and California, and two flights above growing agriculture in Iowa. Two flights were also made under OCO-2 satellite ground tracks. Analyses show the retrievals of lidar range and CO2 column absorption, and mixing ratio worked well when measuring over topography with rapidly changing height and reflectivity, and through thin clouds and aerosol scattering. The lidar measurements clearly

Diurnal changes of remote sensing reflectance over Chesapeake Bay: Observations from the Airborne Compact Atmospheric Mapper

NASA Astrophysics Data System (ADS)

Zhang, Minwei; Hu, Chuanmin; Cannizzaro, Jennifer; Kowalewski, Matthew G.; Janz, Scott J.

2018-01-01

Using hyperspectral data collected by the Airborne Compact Atmospheric Mapper (ACAM) and a shipborne radiometer in Chesapeake Bay in July-August 2011, this study investigates diurnal changes of surface remote sensing reflectance (Rrs). Atmospheric correction of ACAM data is performed using the traditional "black pixel" approach through radiative transfer based look-up-tables (LUTs) with non-zero Rrs in the near-infrared (NIR) accounted for by iterations. The ACAM-derived Rrs was firstly evaluated through comparison with Rrs derived from the Moderate Resolution Imaging Spectroradiometer satellite measurements, and then validated against in situ Rrs using a time window of ±1 h or ±3 h. Results suggest that the uncertainties in ACAM-derived Rrs are generally comparable to those from MODIS satellite measurements over coastal waters, and therefore may be used to assess whether Rrs diurnal changes observed by ACAM are realistic (i.e., with changes > 2 × uncertainties). Diurnal changes observed by repeated ACAM measurements reaches up to 66.8% depending on wavelength and location and are consistent with those from the repeated in situ Rrs measurements. These findings suggest that once airborne data are processed using proper algorithms and validated using in situ data, they are suitable for assessing diurnal changes in moderately turbid estuaries such as Chesapeake Bay. The findings also support future geostationary satellite missions that are particularly useful to assess short-term changes.

Airborne and ground based lidar measurements of the atmospheric pressure profile

NASA Technical Reports Server (NTRS)

Korb, C. Laurence; Schwemmer, Geary K.; Dombrowski, Mark; Weng, Chi Y.

1989-01-01

The first high accuracy remote measurements of the atmospheric pressure profile have been made. The measurements were made with a differential absorption lidar system that utilizes tunable alexandrite lasers. The absorption in the trough between two lines in the oxygen A-band near 760 nm was used for probing the atmosphere. Measurements of the two-dimensional structure of the pressure field were made in the troposphere from an aircraft looking down. Also, measurements of the one-dimensional structure were made from the ground looking up. Typical pressure accuracies for the aircraft measurements were 1.5-2 mbar with a 30-m vertical resolution and a 100-shot average (20 s), which corresponds to a 2-km horizontal resolution. Typical accuracies for the upward viewing ground based measurements were 2.0 mbar for a 30-m resolution and a 100-shot average.

ARM Airborne Carbon Measurements (ARM-ACME) and ARM-ACME 2.5 Final Campaign Reports

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biraud, S. C.; Tom, M. S.; Sweeney, C.

2016-01-01

We report on a 5-year multi-institution and multi-agency airborne study of atmospheric composition and carbon cycling at the Atmospheric Radiation Measurement (ARM) Climate Research Facility’s Southern Great Plains (SGP) site, with scientific objectives that are central to the carbon-cycle and radiative-forcing goals of the U.S. Global Change Research Program and the North American Carbon Program (NACP). The goal of these measurements is to improve understanding of 1) the carbon exchange of the Atmospheric Radiation Measurement (ARM) SGP region; 2) how CO 2 and associated water and energy fluxes influence radiative-forcing, convective processes, and CO 2 concentrations over the ARM SGPmore » region, and 3) how greenhouse gases are transported on continental scales.« less

Evaluation of an airborne triple-pulsed 2 μm IPDA lidar for simultaneous and independent atmospheric water vapor and carbon dioxide measurements.

PubMed

Refaat, Tamer F; Singh, Upendra N; Yu, Jirong; Petros, Mulugeta; Ismail, Syed; Kavaya, Michael J; Davis, Kenneth J

2015-02-20

Water vapor and carbon dioxide are the most dominant greenhouse gases directly contributing to the Earth's radiation budget and global warming. A performance evaluation of an airborne triple-pulsed integrated path differential absorption (IPDA) lidar system for simultaneous and independent monitoring of atmospheric water vapor and carbon dioxide column amounts is presented. This system leverages a state-of-the-art Ho:Tm:YLF triple-pulse laser transmitter operating at 2.05 μm wavelength. The transmitter provides wavelength tuning and locking capabilities for each pulse. The IPDA lidar system leverages a low risk and technologically mature receiver system based on InGaAs pin detectors. Measurement methodology and wavelength setting are discussed. The IPDA lidar return signals and error budget are analyzed for airborne operation on-board the NASA B-200. Results indicate that the IPDA lidar system is capable of measuring water vapor and carbon dioxide differential optical depth with 0.5% and 0.2% accuracy, respectively, from an altitude of 8 km to the surface and with 10 s averaging. Provided availability of meteorological data, in terms of temperature, pressure, and relative humidity vertical profiles, the differential optical depth conversion into weighted-average column dry-air volume-mixing ratio is also presented.

Advances in High Energy Solid-State Pulsed 2-Micron Lidar Development for Ground and Airborne Wind, Water Vapor and CO2 Measurements

NASA Technical Reports Server (NTRS)

Singh, Upendra N.; Yu, Jirong; Petros, Mulugeta; Refaat, Tamer; Kavaya, Michael J.; Remus, Ruben

2015-01-01

NASA Langley Research Center has a long history of developing 2-micron lasers. From fundamental spectroscopy research, theoretical prediction of new materials, laser demonstration and engineering of lidar systems, it has been a very successful program spanning around two decades. Successful development of 2-micron lasers has led to development of a state-of-the-art compact lidar transceiver for a pulsed coherent Doppler lidar system for wind measurement with an unprecedented laser pulse energy of 250 millijoules in a rugged package. This high pulse energy is produced by a Ho:Tm:LuLiF laser with an optical amplifier. While the lidar is meant for use as an airborne instrument, ground-based tests were carried out to characterize performance of the lidar. Atmospheric measurements will be presented, showing the lidar's capability for wind measurement in the atmospheric boundary layer and free troposphere. Lidar wind measurements are compared to a balloon sonde, showing good agreement between the two sensors. Similar architecture has been used to develop a high energy, Ho:Tm:YLF double-pulsed 2-micron Integrated Differential Absorption Lidar (IPDA) instrument based on direct detection technique that provides atmospheric column CO2 measurements. This instrument has been successfully used to measure atmospheric CO2 column density initially from a ground mobile lidar trailer, and then it was integrated on B-200 plane and 20 hours of flight measurement were made from an altitude ranging 1500 meters to 8000 meters. These measurements were compared to in-situ measurements and National Oceanic and Atmospheric Administration (NOAA) airborne flask measurement to derive the dry mixing ratio of the column CO2 by reflecting the signal by various reflecting surfaces such as land, vegetation, ocean surface, snow and sand. The lidar measurements when compared showed a very agreement with in-situ and airborne flask measurement. NASA Langley Research Center is currently developing a

Airborne lidar/radiometric measurements of cirrus cloud parameters and their application to LOWTRAN radiance evaluations

NASA Technical Reports Server (NTRS)

Uthe, Edward E.

1990-01-01

SRI has assembled an airborne lidar/radiometric instrumentation suite for mapping cirrus cloud distribution and analyzing cirrus cloud optical properties. Operation of upward viewing infrared radiometers from an airborne platform provides the optimum method of measuring high altitude cold cloud radiative properties with minimum interference from the thermal emission by the earth's surface and lower atmospheric components. Airborne installed sensors can also operate over large regional areas including water, urban, and mountain surfaces and above lower atmospheric convective clouds and haze layers. Currently available sensors installed on the SRI Queen Air aircraft are illustrated. Lidar and radiometric data records are processed for real time viewing on a color video screen. A cirrus cloud data example is presented as a black and white reproduction of a color display of data at the aircraft altitude of 12,000 ft, the 8 to 14 micron atmospheric radiation background was equivalent to a blackbody temperature of about -60 C and, therefore, the radiometer did not respond strongly to low density cirrus cloud concentrations detected by the lidar. Cloud blackbody temperatures (observed by radiometer) are shown plotted against midcloud temperatures (derived from lidar observed cloud heights and supporting temperature profiles) for data collected on 30 June and 28 July.

Airborne Measurements of atmospheric PAH's across Europe

NASA Astrophysics Data System (ADS)

Davison, B.; Jaward, F.; Jones, K.; Lee, R.

2003-04-01

Atmospheric measurements of PAHs were taken aboard the DRL Falcon 20 during May 2001. A sampling system was designed to work aboard this aircraft platform. Particulate PAHs were collected on a glass fiber filter (GFF) with their gaseous component concentrated on a polyurethane foam sheets located behind the filter. Typically sampling volumes of between 20-50m^3 were collected which equated to a collection time of about 30minutes. In this way the distance travelled was kept within an acceptable level, about 60 nautical miles. The average concentrations of the data set for phenanthrene was 450 pg m-3 while values for many of the heavier PAH marker compounds used in the UK such as benzo(a)pyrene, diben(ah)anthracene were below the detection limits on all flights. The results will be discussed with consideration of location, altitude and airmass trajectory.

ARM Airborne Carbon Measurements VI (ACME VI) Science Plan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biraud, S

2015-12-01

From October 1 through September 30, 2016, the Atmospheric Radiation Measurement (ARM) Aerial Facility will deploy the Cessna 206 aircraft over the Southern Great Plains (SGP) site, collecting observations of trace-gas mixing ratios over the ARM’s SGP facility. The aircraft payload includes two Atmospheric Observing Systems, Inc., analyzers for continuous measurements of CO2 and a 12-flask sampler for analysis of carbon cycle gases (CO2, CO, CH4, N2O, 13CO2, 14CO2, carbonyl sulfide, and trace hydrocarbon species, including ethane). The aircraft payload also includes instrumentation for solar/infrared radiation measurements. This research is supported by the U.S. Department of Energy’s ARM Climate Researchmore » Facility and Terrestrial Ecosystem Science Program and builds upon previous ARM Airborne Carbon Measurements (ARM-ACME) missions. The goal of these measurements is to improve understanding of 1) the carbon exchange at the SGP site, 2) how CO2 and associated water and energy fluxes influence radiative forcing, convective processes and CO2 concentrations over the SGP site, and 3) how greenhouse gases are transported on continental scales.« less

Airborne mapping of Seoul's atmosphere: Trace gas measurements from GeoTASO during KORUS-AQ

NASA Astrophysics Data System (ADS)

Nowlan, C. R.; Al-Saadi, J. A.; Castellanos, P.; Chance, K.; Gonzalez Abad, G.; Janz, S. J.; Judd, L.; Kowalewski, M. G.; Liu, X.

2017-12-01

The Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) instrument is a pushbroom airborne remote sensing instrument capable of making measurements of air quality and ocean color using backscattered UV and visible light. GeoTASO is an airborne test-bed for the upcoming Tropospheric Emissions: Monitoring of Pollution (TEMPO) and Geostationary Environment Monitoring Spectrometer (GEMS) geostationary satellite missions, which will measure air quality over North America and Asia, respectively. GeoTASO also acts as a satellite analogue during field campaigns. GeoTASO flew on the NASA Langley Research Center UC-12 aircraft during the Korea-United States Air Quality Study in May-June 2016, collecting spectra over South Korea during 30 flights over 19 flight days. These observations can be used to derive 2-D maps of tropospheric trace gases including ozone, nitrogen dioxide, sulfur dioxide, formaldehyde, nitrous acid and glyoxal below the aircraft at spatial resolutions between 250 m x 250 m and 1 km x 1 km, depending on the gas. We present spatially resolved trace gas retrievals over Seoul and its surrounding industrial regions, and comparisons with correlative satellite and campaign data.

Science Measurement Requirements for Imaging Spectrometers from Airborne to Spaceborne

NASA Technical Reports Server (NTRS)

Green, Robert O.; Asner, Gregory P.; Boardman, Joseph; Ungar, Stephen; Mouroulis, Pantazis

2006-01-01

This slide presentation reviews the objectives of the work to create imaging spectrometers. The science objectives are to remotely determine the properties of the surface and atmosphere (physics, chemistry and biology) revealed by the interaction of electromagnetic energy with matter via spectroscopy. It presents a review the understanding of spectral, radiometric and spatial science measurement requirements for imaging spectrometers based upon science research results from past and current airborne and spaceborne instruments. It also examines the future requirements that will enable the next level of imaging spectroscopy science.

2-micron Double Pulsed IPDA Lidar for Atmospheric CO2 Measurement

NASA Astrophysics Data System (ADS)

Yu, Jirong; Petros, Mulugeta; Refaat, Tamer; Reithmaier, Karl; Remus, Ruben; Singh, Upendra; Johnson, Will; Boyer, Charlie; Fay, James; Johnston, Susan; Murchison, Luke; Scola, Tory

2015-04-01

We have developed a high energy pulsed 2-micron IPDA lidar instrument to measure the atmospheric CO2 column density. The IPDA lidar is operated on the long wavelength wing of R(30) CO2 line at 2050.967 nm (4875.749 cm-1) in the side-line operation mode. The R(30) line is an excellent absorption line for the measurements of CO2 in 2µm wavelength region with regard to the strength of the absorption lines, low susceptibility to atmospheric temperature variability, and freedom from problematic interference with other absorption lines. The Ho:Tm:YLF laser transmitter is designed to be operated in a unique double pulse format that can produce two-pulse pair in 10 Hz operation. Typically, the output energies of the laser transmitter are 100mJ and 45mJ for the first pulse and the second pulse, respectively. We injection seed the first pulse with on-line frequency and the second pulse with off-line frequency. The IPDA lidar instrument size, weight and power consumption were restricted to small research aircraft payload requirements. The airborne IPDA lidar instrument measures the total integrated column content of CO2 from the instrument to the ground but with weighting that can be tuned by controlling the transmitted wavelengths. Therefore, the transmitter could be tuned to weight the column measurement to the surface for optimum CO2 interaction studies or up to the free troposphere for optimum transport studies. The 2-μm CO2 IPDA lidar airborne demonstration was conducted during March 20, 2014 through April 10, 2014. IPDA lidar airborne flights included various operating and environmental conditions. Environmental conditions included different flight altitude up to 8.3 km, different ground target conditions such as vegetation, soil, ocean, snow and sand and different cloud conditions. Besides, some flights targeted power plant incinerators for investigating the IPDA sensitivity to CO2 plums. The lidar instrument is robust during all of the flights. This paper describes

Profiling of Atmospheric Water Vapor from the SSM/T-2 Radiometric Measurements

NASA Technical Reports Server (NTRS)

Wang, J. R.

2000-01-01

An advantage of using the millimeter-wave measurements for water vapor profiling is the ability to probe beyond a moderate cloud cover. Such a capability has been demonstrated from an airborne MIR (Millimeter-wave Imaging Radiometer) flight over the Pacific Ocean during an intense observation period of TOGA/COARE (Tropical Ocean Global Atmosphere/ Couple Ocean Atmospheric Response Experiment) in early 1993. A Cloud Lidar System (CLS) and MODIS Airborne Simulator (MAS) were on board the same aircraft to identify the presence of clouds and cloud type. The retrieval algorithm not only provides output of a water vapor profile, but also the cloud liquid water and approximate cloud altitude required to satisfy convergence of the retrieval. The validity of these cloud parameters has not been verified previously. In this document, these cloud parameters are compared with those derived from concurrent measurements from the CLS and AMPR (Advanced Microwave Precipitation Radiometer).

Retrieval of atmospheric backscatter and extinction profiles with the aladin airborne demonstrator (A2D)

NASA Astrophysics Data System (ADS)

Geiss, Alexander; Marksteiner, Uwe; Lux, Oliver; Lemmerz, Christian; Reitebuch, Oliver; Kanitz, Thomas; Straume-Lindner, Anne Grete

2018-04-01

By the end of 2017, the European Space Agency (ESA) will launch the Atmospheric laser Doppler instrument (ALADIN), a direct detection Doppler wind lidar operating at 355 nm. An important tool for the validation and optimization of ALADIN's hardware and data processors for wind retrievals with real atmospheric signals is the ALADIN airborne demonstrator A2D. In order to be able to validate and test aerosol retrieval algorithms from ALADIN, an algorithm for the retrieval of atmospheric backscatter and extinction profiles from A2D is necessary. The A2D is utilizing a direct detection scheme by using a dual Fabry-Pérot interferometer to measure molecular Rayleigh signals and a Fizeau interferometer to measure aerosol Mie returns. Signals are captured by accumulation charge coupled devices (ACCD). These specifications make different steps in the signal preprocessing necessary. In this paper, the required steps to retrieve aerosol optical products, i. e. particle backscatter coefficient βp, particle extinction coefficient αp and lidar ratio Sp from A2D raw signals are described.

Airborne remote sensing and in situ measurements of atmospheric CO2 to quantify point source emissions

NASA Astrophysics Data System (ADS)

Krings, Thomas; Neininger, Bruno; Gerilowski, Konstantin; Krautwurst, Sven; Buchwitz, Michael; Burrows, John P.; Lindemann, Carsten; Ruhtz, Thomas; Schüttemeyer, Dirk; Bovensmann, Heinrich

2018-02-01

Reliable techniques to infer greenhouse gas emission rates from localised sources require accurate measurement and inversion approaches. In this study airborne remote sensing observations of CO2 by the MAMAP instrument and airborne in situ measurements are used to infer emission estimates of carbon dioxide released from a cluster of coal-fired power plants. The study area is complex due to sources being located in close proximity and overlapping associated carbon dioxide plumes. For the analysis of in situ data, a mass balance approach is described and applied, whereas for the remote sensing observations an inverse Gaussian plume model is used in addition to a mass balance technique. A comparison between methods shows that results for all methods agree within 10 % or better with uncertainties of 10 to 30 % for cases in which in situ measurements were made for the complete vertical plume extent. The computed emissions for individual power plants are in agreement with results derived from emission factors and energy production data for the time of the overflight.

Airborne and Ground-Based Measurements Using a High-Performance Raman Lidar

NASA Technical Reports Server (NTRS)

Whiteman, David N.; Rush, Kurt; Rabenhorst, Scott; Welch, Wayne; Cadirola, Martin; McIntire, Gerry; Russo, Felicita; Adam, Mariana; Venable, Demetrius; Connell, Rasheen;

An overview of Airborne Data for Assessing Models (ADAM): a web development effort to effectively disseminate airborne data products

NASA Astrophysics Data System (ADS)

Mangosing, D. C.; Chen, G.; Kusterer, J.; Rinsland, P.; Perez, J.; Sorlie, S.; Parker, L.

2011-12-01

One of the objectives of the NASA Langley Research Center's MEaSURES project, "Creating a Unified Airborne Database for Model Assessment", is the development of airborne Earth System Data Records (ESDR) for the regional and global model assessment and validation activities performed by the tropospheric chemistry and climate modeling communities. The ongoing development of ADAM, a web site designed to access a unified, standardized and relational ESDR database, meets this objective. The ESDR database is derived from publically available data sets, from NASA airborne field studies to airborne and in-situ studies sponsored by NOAA, NSF, and numerous international partners. The ADAM web development activities provide an opportunity to highlight a growing synergy between the Airborne Science Data for Atmospheric Composition (ASD-AC) group at NASA Langley and the NASA Langley's Atmospheric Sciences Data Center (ASDC). These teams will collaborate on the ADAM web application by leveraging the state-of-the-art service and message-oriented data distribution architecture developed and implemented by ASDC and using a web-based tool provided by the ASD-AC group whose user interface accommodates the nuanced perspective of science users in the atmospheric chemistry and composition and climate modeling communities.

Exploring atmospheric radon with airborne gamma-ray spectroscopy

NASA Astrophysics Data System (ADS)

Baldoncini, Marica; Albéri, Matteo; Bottardi, Carlo; Minty, Brian; Raptis, Kassandra G. C.; Strati, Virginia; Mantovani, Fabio

2017-12-01

222Rn is a noble radioactive gas produced along the 238U decay chain, which is present in the majority of soils and rocks. As 222Rn is the most relevant source of natural background radiation, understanding its distribution in the environment is of great concern for investigating the health impacts of low-level radioactivity and for supporting regulation of human exposure to ionizing radiation in modern society. At the same time, 222Rn is a widespread atmospheric tracer whose spatial distribution is generally used as a proxy for climate and pollution studies. Airborne gamma-ray spectroscopy (AGRS) always treated 222Rn as a source of background since it affects the indirect estimate of equivalent 238U concentration. In this work the AGRS method is used for the first time for quantifying the presence of 222Rn in the atmosphere and assessing its vertical profile. High statistics radiometric data acquired during an offshore survey are fitted as a superposition of a constant component due to the experimental setup background radioactivity plus a height dependent contribution due to cosmic radiation and atmospheric 222Rn. The refined statistical analysis provides not only a conclusive evidence of AGRS 222Rn detection but also a (0.96 ± 0.07) Bq/m3 222Rn concentration and a (1318 ± 22) m atmospheric layer depth fully compatible with literature data.

Turbulence in breaking mountain waves and atmospheric rotors estimated from airborne in situ and Doppler radar measurements.

PubMed

Strauss, Lukas; Serafin, Stefano; Haimov, Samuel; Grubišić, Vanda

2015-10-01

Atmospheric turbulence generated in flow over mountainous terrain is studied using airborne in situ and cloud radar measurements over the Medicine Bow Mountains in southeast Wyoming, USA. During the NASA Orographic Clouds Experiment (NASA06) in 2006, two complex mountain flow cases were documented by the University of Wyoming King Air research aircraft carrying the Wyoming Cloud Radar. The structure of turbulence and its intensity across the mountain range are described using the variance of vertical velocity σw2 and the cube root of the energy dissipation rate ɛ 1/3 (EDR). For a quantitative analysis of turbulence from the cloud radar, the uncertainties in the Doppler wind retrieval have to be taken into account, such as the variance of hydrometeor fall speed and the contamination of vertical Doppler velocity by the horizontal wind. A thorough analysis of the uncertainties shows that 25% accuracy or better can be achieved in regions of moderate to severe turbulence in the lee of the mountains, while only qualitative estimates of turbulence intensity can be obtained outside the most turbulent regions. Two NASA06 events exhibiting large-amplitude mountain waves, mid-tropospheric wave breaking, and rotor circulations are examined. Moderate turbulence is found in a wave-breaking region with σw2 and EDR reaching 4.8 m 2 s -2 and 0.25 m 2/3 s -1 , respectively. Severe turbulence is measured within the rotor circulations with σw2 and EDR respectively in the ranges of 7.8-16.4 m 2 s -2 and 0.50-0.77 m 2/3 s -1 . A unique result of this study is the quantitative estimation of the intensity of turbulence and its spatial distribution in the interior of atmospheric rotors, provided by the radar-derived turbulence fields.

Airborne Shaped Sonic Boom Demonstration Pressure Measurements with Computational Fluid Dynamics Comparisons

NASA Technical Reports Server (NTRS)

Haering, Edward A., Jr.; Murray, James E.; Purifoy, Dana D.; Graham, David H.; Meredith, Keith B.; Ashburn, Christopher E.; Stucky, Mark

2005-01-01

The Shaped Sonic Boom Demonstration project showed for the first time that by careful design of aircraft contour the resultant sonic boom can maintain a tailored shape, propagating through a real atmosphere down to ground level. In order to assess the propagation characteristics of the shaped sonic boom and to validate computational fluid dynamics codes, airborne measurements were taken of the pressure signatures in the near field by probing with an instrumented F-15B aircraft, and in the far field by overflying an instrumented L-23 sailplane. This paper describes each aircraft and their instrumentation systems, the airdata calibration, analysis of the near- and far-field airborne data, and shows the good to excellent agreement between computational fluid dynamics solutions and flight data. The flights of the Shaped Sonic Boom Demonstration aircraft occurred in two phases. Instrumentation problems were encountered during the first phase, and corrections and improvements were made to the instrumentation system for the second phase, which are documented in the paper. Piloting technique and observations are also given. These airborne measurements of the Shaped Sonic Boom Demonstration aircraft are a unique and important database that will be used to validate design tools for a new generation of quiet supersonic aircraft.

Airborne Two-Micron Double-Pulse IPDA Lidar Validation for Carbon Dioxide Measurements Over Land

NASA Astrophysics Data System (ADS)

Refaat, Tamer F.; Singh, Upendra N.; Yu, Jirong; Petros, Mulugeta; Remus, Ruben; Ismail, Syed

2018-04-01

An airborne double-pulse 2-μm Integrated Path Differential Absorption (IPDA) lidar has been developed at NASA LaRC for measuring atmospheric CO2. IPDA was validated using NASA B-200 aircraft over land and ocean under different conditions. IPDA evaluation for land vegetation returns, during full day background conditions, are presented. IPDA CO2 measurements compare well with model results driven from on-board insitu sensor data. These results also indicate that CO2 measurement bias is consistent with that from ocean surface returns.

Initial Retrieval Validation from the Joint Airborne IASI Validation Experiment (JAIVEx)

NASA Technical Reports Server (NTRS)

Zhou, Daniel K.; Liu, Xu; Smith, WIlliam L.; Larar, Allen M.; Taylor, Jonathan P.; Revercomb, Henry E.; Mango, Stephen A.; Schluessel, Peter; Calbet, Xavier

2007-01-01

The Joint Airborne IASI Validation Experiment (JAIVEx) was conducted during April 2007 mainly for validation of the Infrared Atmospheric Sounding Interferometer (IASI) on the MetOp satellite, but also included a strong component focusing on validation of the Atmospheric InfraRed Sounder (AIRS) aboard the AQUA satellite. The cross validation of IASI and AIRS is important for the joint use of their data in the global Numerical Weather Prediction process. Initial inter-comparisons of geophysical products have been conducted from different aspects, such as using different measurements from airborne ultraspectral Fourier transform spectrometers (specifically, the NPOESS Airborne Sounder Testbed Interferometer (NAST-I) and the Scanning-High resolution Interferometer Sounder (S-HIS) aboard the NASA WB-57 aircraft), UK Facility for Airborne Atmospheric Measurements (FAAM) BAe146-301 aircraft insitu instruments, dedicated dropsondes, radiosondes, and ground based Raman Lidar. An overview of the JAIVEx retrieval validation plan and some initial results of this field campaign are presented.

Double-Pulse Two-Micron IPDA Lidar Simulation for Airborne Carbon Dioxide Measurements

NASA Technical Reports Server (NTRS)

Refaat, Tamer F.; Singh, Upendra N.; Yu, Jirong; Petros, Mulugeta

2015-01-01

An advanced double-pulsed 2-micron integrated path differential absorption lidar has been developed at NASA Langley Research Center for measuring atmospheric carbon dioxide. The instrument utilizes a state-of-the-art 2-micron laser transmitter with tunable on-line wavelength and advanced receiver. Instrument modeling and airborne simulations are presented in this paper. Focusing on random errors, results demonstrate instrument capabilities of performing precise carbon dioxide differential optical depth measurement with less than 3% random error for single-shot operation from up to 11 km altitude. This study is useful for defining CO2 measurement weighting, instrument setting, validation and sensitivity trade-offs.

Efficacy of atmospheric pressure dielectric barrier discharge for inactivating airborne pathogens

DOE PAGES

Romero-Mangado, Jaione; Dey, Avishek; Diaz-Cartagena, Diana C.; ...

2017-07-05

Atmospheric pressure plasmas have gained attention in recent years for several environmental applications. This technology could potentially be used to deactivate airborne microorganisms, surface-bound microorganisms, and biofilms. Here, the authors explore the efficacy of the atmospheric pressure dielectric barrier discharge (DBD) to inactivate airborne Staphylococcus epidermidis and Aspergillus niger that are opportunistic pathogens associated with nosocomial infections. This technology uses air as the source of gas and does not require any process gas such as helium, argon, nitrogen, or hydrogen. Moreover, the effect of DBD was studied on aerosolized S. epidermidis and aerosolized A. niger spores via scanning electron microscopymore » (SEM). The morphology observed on the SEM micrographs showed deformations in the cellular structure of both microorganisms. Cell structure damage upon interaction with the DBD suggests leakage of vital cellular materials, which is a key mechanism for microbial inactivation. The chemical structure of the cell surface of S. epidermidis was also analyzed by near edge x-ray absorption fine structure spectroscopy before and after DBD exposure. Our results from surface analysis revealed that reactive oxygen species from the DBD discharge contributed to alterations on the chemistry of the cell membrane/cell wall of S. epidermidis.« less

Efficacy of atmospheric pressure dielectric barrier discharge for inactivating airborne pathogens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Romero-Mangado, Jaione; Dey, Avishek; Diaz-Cartagena, Diana C.

Atmospheric pressure plasmas have gained attention in recent years for several environmental applications. This technology could potentially be used to deactivate airborne microorganisms, surface-bound microorganisms, and biofilms. Here, the authors explore the efficacy of the atmospheric pressure dielectric barrier discharge (DBD) to inactivate airborne Staphylococcus epidermidis and Aspergillus niger that are opportunistic pathogens associated with nosocomial infections. This technology uses air as the source of gas and does not require any process gas such as helium, argon, nitrogen, or hydrogen. Moreover, the effect of DBD was studied on aerosolized S. epidermidis and aerosolized A. niger spores via scanning electron microscopymore » (SEM). The morphology observed on the SEM micrographs showed deformations in the cellular structure of both microorganisms. Cell structure damage upon interaction with the DBD suggests leakage of vital cellular materials, which is a key mechanism for microbial inactivation. The chemical structure of the cell surface of S. epidermidis was also analyzed by near edge x-ray absorption fine structure spectroscopy before and after DBD exposure. Our results from surface analysis revealed that reactive oxygen species from the DBD discharge contributed to alterations on the chemistry of the cell membrane/cell wall of S. epidermidis.« less

Elucidating Carbon Exchange at the Regional Scale Via Airborne Eddy Covariance Flux Measurements

NASA Astrophysics Data System (ADS)

Hannun, R. A.; Wolfe, G. M.; Kawa, S. R.; Newman, P. A.; Hanisco, T. F.; Diskin, G. S.; DiGangi, J. P.; Nowak, J. B.; Barrick, J. D. W.; Thornhill, K. L., II; Noormets, A.; Vargas, R.; Clark, K. L.; Kustas, W. P.

2017-12-01

Direct flux observations from aircraft provide a unique tool for probing greenhouse gas (GHG) sources and sinks on a regional scale. Airborne eddy covariance, which relies on high-frequency, simultaneous measurements of fluctuations in concentration and vertical wind speed, is a robust method for quantifying surface-atmosphere exchange. We have assembled and flown an instrument payload onboard the NASA C-23 Sherpa aircraft capable of measuring CO2, CH4, H2O, and heat fluxes. Flights for the Carbon Airborne Flux Experiment (CARAFE) took place during September 2016 and May 2017 based out of Wallops Flight Facility, VA. Flight tracks covered a variety of ecosystems and land-use types in the Mid-Atlantic, including forests, croplands, and wetlands. Carbon fluxes are derived using eddy covariance and wavelet analysis. Our results show a strong drawdown of CO2 and near-zero CH4 emissions from crops and dry-land forest, but seasonally strong CH4 flux from wetland forest. CARAFE flux data will also be compared with observations from several flux towers along the flight path to complement the airborne measurements. We will further assess the effects of land surface type and seasonal variability in carbon exchange. Regional-scale flux observations from CARAFE supply a useful constraint for improving top-down and bottom up estimates of carbon sources and sinks.

Airborne 2-Micron Double-Pulsed Integrated Path Differential Absorption Lidar for Column CO2 Measurement

NASA Technical Reports Server (NTRS)

Singh, Upendra N.; Yu, Jirong; Petros, Mulugeta; Refaat, Tamer F.; Remus, Ruben G.; Fay, James J.; Reithmaier, Karl

2014-01-01

Double-pulse 2-micron lasers have been demonstrated with energy as high as 600 millijouls and up to 10 Hz repetition rate. The two laser pulses are separated by 200 microseconds and can be tuned and locked separately. Applying double-pulse laser in DIAL system enhances the CO2 measurement capability by increasing the overlap of the sampled volume between the on-line and off-line. To avoid detection complicity, integrated path differential absorption (IPDA) lidar provides higher signal-to-noise ratio measurement compared to conventional range-resolved DIAL. Rather than weak atmospheric scattering returns, IPDA rely on the much stronger hard target returns that is best suited for airborne platforms. In addition, the IPDA technique measures the total integrated column content from the instrument to the hard target but with weighting that can be tuned by the transmitter. Therefore, the transmitter could be tuned to weight the column measurement to the surface for optimum CO2 interaction studies or up to the free troposphere for optimum transport studies. Currently, NASA LaRC is developing and integrating a double-Pulsed 2-micron direct detection IPDA lidar for CO2 column measurement from an airborne platform. The presentation will describe the development of the 2-micron IPDA lidar system and present the airborne measurement of column CO2 and will compare to in-situ measurement for various ground target of different reflectivity.

Airborne optic and magnetic observatory (ABOMO) for the investigation of the ionosphere, magnetosphere, and atmospheric proceses

NASA Astrophysics Data System (ADS)

Raspopov, Oleg M.; Pochtarev, V. I.; Domaratskij, Serguej N.

1993-11-01

The St. Petersburg Filial (Division) of IZMIRAN has recently initiated a major new research project involving the Airborne Optic and Magnetic Observatory (ABOMO). ABOMO is designed specifically for studies of auroral, magnetic, ionospheric and atmospheric phenomena including ozone and other important atmospheric constituents. The observatory is constructed aboard a modified four-engine turboprop aircraft AN-12.

Analysis of Vertical Weighting Functions for Lidar Measurements of Atmospheric CO2 and O2

NASA Astrophysics Data System (ADS)

Kooi, S.; Mao, J.; Abshire, J. B.; Browell, E. V.; Weaver, C. J.; Kawa, S. R.

2011-12-01

Several NASA groups have developed integrated path differential absorption (IPDA) lidar approaches to measure atmospheric CO2 concentrations from space as a candidates for NASA's ASCENDS space mission. For example, the Goddard CO2 Sounder approach uses two pulsed lasers to simultaneously measure both CO2 and O2 absorption in the vertical path to the surface at a number of wavelengths across a CO2 line near 1572 nm and an O2 line doublet near 764 nm. The measurements of CO2 and O2 absorption allow computing their vertically weighted number densities and then their ratios for estimating CO2 concentration relative to dry air. Since both the CO2 and O2 densities and their absorption line-width decrease with altitude, the absorption response (or weighting function) varies with both altitude and absorption wavelength. We have used some standard atmospheres and HITRAN 2008 spectroscopy to calculate the vertical weighting functions for two CO2 lines near 1571 nm and the O2 lines near 764.7 and 1260 nm for candidate online wavelength selections for ASCENDS. For CO2, the primary candidate on-line wavelengths are 10-12 pm away from line center with the weighting function peaking in the atmospheric boundary layer to measure CO2 sources and sinks at the surface. Using another on-line wavelength 3-5 pm away from line center allows the weighting function to peak in the mid- to upper troposphere, which is sensitive to CO2 transport in the free atmosphere. The Goddard CO2 sounder team developed an airborne precursor version of a space instrument. During the summers of 2009, 2010 and 2011 it has participated in airborne measurement campaigns over a variety of different sites in the US, flying with other NASA ASCENDS lidar candidates along with accurate in-situ atmospheric sensors. All flights used altitude patterns with measurements at steps in altitudes between 3 and 13 km, along with spirals from 13 km altitude to near the surface. Measurements from in-situ sensors allowed an

An airborne sunphotometer for use with helicopters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walthall, C.L.; Halthore, R.N.; Elman, G.C.

1996-04-01

One solution for atmospheric correction and calibration of remotely sensed data from airborne platforms is the use of radiometrically calibrated instruments, sunphotometers and an atmospheric radiative transfer model. Sunphotometers are used to measure the direct solar irradiance at the level at which they are operating and the data are used in the computation of atmospheric optical depth. Atmospheric optical depth is an input to atmospheric correction algorithms that convert at-sensor radiance to required surface properties such as reflectance and temperature. Airborne sun photometry has thus far seen limited use and has not been used with a helicopter platform. The hardware,more » software, calibration and deployment of an automatic sun-tracking sunphotometer specifically designed for use on a helicopter are described. Sample data sets taken with the system during the 1994 Boreal Ecosystem and Atmosphere Study (BOREAS) are presented. The addition of the sun photometer to the helicopter system adds another tool for monitoring the environment and makes the helicopter remote sensing system capable of collecting calibrated, atmospherically corrected data independent of the need for measurements from other systems.« less

Double-Pulsed 2-Micrometer Lidar Validation for Atmospheric CO2 Measurements

NASA Technical Reports Server (NTRS)

Singh, Upendra N.; Refaat, Tamer F.; Yu, Jirong; Petros, Mulugeta; Remus, Ruben

2015-01-01

A double-pulsed, 2-micron Integrated Path Differential Absorption (IPDA) lidar instrument for atmospheric carbon dioxide (CO2) measurements is successfully developed at NASA Langley Research Center (LaRC). Based on direct detection technique, the instrument can be operated on ground or onboard a small aircraft. Key features of this compact, rugged and reliable IPDA lidar includes high transmitted laser energy, wavelength tuning, switching and locking, and sensitive detection. As a proof of concept, the IPDA ground and airborne CO2 measurement and validation will be presented. IPDA lidar CO2 measurements ground validation were conducted at NASA LaRC using hard targets and a calibrated in-situ sensor. Airborne validation, conducted onboard the NASA B-200 aircraft, included CO2 plum detection from power stations incinerators, comparison to in-flight CO2 in-situ sensor and comparison to air sampling at different altitude conducted by NOAA at the same site. Airborne measurements, spanning for 20 hours, were obtained from different target conditions. Ground targets included soil, vegetation, sand, snow and ocean. In addition, cloud slicing was examined over the ocean. These flight validations were conducted at different altitudes, up to 7 km, with different wavelength controlled weighing functions. CO2 measurement results agree with modeling conducted through the different sensors, as will be discussed.

A unique airborne observation. [Martian atmospheric temperature and abundances from occultation of Epsilon Geminorum

NASA Technical Reports Server (NTRS)

Elliot, J. L.; Dunham, E.; Church, C.

1976-01-01

The occultation of 3rd magnitude Epsilon Geminorum by Mars was observed using a 36-inch telescope equipped with a photoelectric photometer at the bent Cassegrain focus, carried aboard the Kuiper Airborne Observatory at altitudes up to 45,000 feet. Scintillation from the earth's atmosphere was greatly reduced in comparison with ground observations. The observations clearly show the central flash, caused by the symmetrical refraction of light by the atmosphere of Mars. The data are being analyzed to obtain temperature profiles and to assess the relative abundance of argon and carbon dioxide in the atmosphere of the planet.

Airborne Flux Measurements of Volatile Organic Compounds and NOx over a European megacity

NASA Astrophysics Data System (ADS)

Shaw, Marvin; Lee, James; Davison, Brian; Misztal, Pawel; Karl, Thomas; Hewitt, Nick; Lewis, Alistair

2014-05-01

Ground level ozone (O3) and nitrogen dioxide (NO2) are priority pollutants whose concentrations are closely regulated by European Union Air Quality Directive 2008/50/EC. O3 is a secondary pollutant, produced from a complex chemical interplay between oxides of nitrogen (NOx = NO + NO2) and volatile organic compounds (VOCs). Whilst the basic atmospheric chemistry leading to O3 formation is generally well understood, there are substantial uncertainties associated with the magnitude of emissions of both VOCs and NOx. At present our knowledge of O3 precursor emissions in the UK is primarily derived from National Atmospheric Emission inventories (NAEI) that provide spatially disaggregated estimates at 1x1km resolution, and these are not routinely tested at city or regional scales. Uncertainties in emissions propagate through into uncertainties in predictions of air quality in the future, and hence the likely effectiveness of control policies on both background and peak O3 and NO2 concentrations in the UK. The Ozone Precursor Fluxes in the Urban Environment (OPFUE) project aims to quantify emission rates for NOx and selected VOCs in and around the megacity of London using airborne eddy covariance (AEC). The mathematical foundation for AEC has been extensively reviewed and AEC measurements of ozone, dimethyl sulphide, CO2 and VOCs have been previously reported. During the summer of 2013, approximately 30 hours of airborne flux measurements of toluene, benzene, NO and NO2 were obtained from the NERC Airborne Research and Survey Facility's (ARSF) Dornier-228 aircraft. Over SE England, flights involved repeated south west to north east transects of ~50 km each over Greater London and it's surrounding suburbs and rural areas, flying at the aircraft's minimum operating flight altitude and airspeed (~300m, 80m/s). Mixing ratios of benzene and toluene were acquired at 2Hz using a proton transfer reaction mass spectrometer (PTR-MS) and compared to twice hourly whole air canister

Tropospheric and Airborne Emission Spectrometers

NASA Technical Reports Server (NTRS)

Glavich, Thomas; Beer, Reinhard

1996-01-01

X This paper describes the development of two related instruments, the Tropospheric Emission Spectrometer (TES) and the Airborne Emission Spectrometer (AES). Both instruments are infrared imaging Fourier Transform Spectrometers, used for measuring the state of the lower atmosphere, and in particular the measurement of ozone and ozone sources and sinks.

Methane airborne measurements and comparison to global models during BARCA

NASA Astrophysics Data System (ADS)

Beck, Veronika; Chen, Huilin; Gerbig, Christoph; Bergamaschi, Peter; Bruhwiler, Lori; Houweling, Sander; Röckmann, Thomas; Kolle, Olaf; Steinbach, Julia; Koch, Thomas; Sapart, Célia J.; van der Veen, Carina; Frankenberg, Christian; Andreae, Meinrat O.; Artaxo, Paulo; Longo, Karla M.; Wofsy, Steven C.

2012-08-01

Tropical regions, especially the Amazon region, account for large emissions of methane (CH4). Here, we present CH4 observations from two airborne campaigns conducted within the BARCA (Balanço Atmosférico Regional de Carbono na Amazônia) project in the Amazon basin in November 2008 (end of the dry season) and May 2009 (end of the wet season). We performed continuous measurements of CH4 onboard an aircraft for the first time in the Amazon region, covering the whole Amazon basin with over 150 vertical profiles between altitudes of 500 m and 4000 m. The observations support the finding of previous ground-based, airborne, and satellite measurements that the Amazon basin is a large source of atmospheric CH4. Isotope analysis verified that the majority of emissions can be attributed to CH4 emissions from wetlands, while urban CH4 emissions could be also traced back to biogenic origin. A comparison of five TM5 based global CH4 inversions with the observations clearly indicates that the inversions using SCIAMACHY observations represent the BARCA observations best. The calculated CH4 flux estimate obtained from the mismatch between observations and TM5-modeled CH4 fields ranges from 36 to 43 mg m-2 d-1 for the Amazon lowland region.

Airborne measurements of solar and planetary near ultraviolet radiation during the NASA/ESA CV-900 spacelab simulation

NASA Technical Reports Server (NTRS)

Sivjee, G. G.

1977-01-01

Results from a comparative study of the feasibility of employing experiment operators on the space shuttle to acquire scientifically worthwhile data are presented. The experiments performed during these tests included spectral observations of the Sun and Venus in the near ultraviolet region. The solar measurements were analyzed to determine ozone abundance in the terrestrial atmosphere. Using a detailed spectral matching technique to compare airborne solar UV measurements with synthetic spectral profiles of sunlight, it is deduced that in winter the total atmospheric ozone abundance is about 0.33 atm/cm at midlatitudes in the northern hemisphere.

Airborne measurements of isoprene and monoterpene emissions from southeastern U.S. forests.

PubMed

Yu, Haofei; Guenther, Alex; Gu, Dasa; Warneke, Carsten; Geron, Chris; Goldstein, Allen; Graus, Martin; Karl, Thomas; Kaser, Lisa; Misztal, Pawel; Yuan, Bin

2017-10-01

Isoprene and monoterpene emission rates are essential inputs for atmospheric chemistry models that simulate atmospheric oxidant and particle distributions. Process studies of the biochemical and physiological mechanisms controlling these emissions are advancing our understanding and the accuracy of model predictions but efforts to quantify regional emissions have been limited by a lack of constraints on regional distributions of ecosystem emission capacities. We used an airborne wavelet-based eddy covariance measurement technique to characterize isoprene and monoterpene fluxes with high spatial resolution during the 2013 SAS (Southeast Atmosphere Study) in the southeastern United States. The fluxes measured by direct eddy covariance were comparable to emissions independently estimated using an indirect inverse modeling approach. Isoprene emission factors based on the aircraft wavelet flux estimates for high isoprene chemotypes (e.g., oaks) were similar to the MEGAN2.1 biogenic emission model estimates for landscapes dominated by oaks. Aircraft flux measurement estimates for landscapes with fewer isoprene emitting trees (e.g., pine plantations), were about a factor of two lower than MEGAN2.1 model estimates. The tendency for high isoprene emitters in these landscapes to occur in the shaded understory, where light dependent isoprene emissions are diminished, may explain the lower than expected emissions. This result demonstrates the importance of accurately representing the vertical profile of isoprene emitting biomass in biogenic emission models. Airborne measurement-based emission factors for high monoterpene chemotypes agreed with MEGAN2.1 in landscapes dominated by pine (high monoterpene chemotype) trees but were more than a factor of three higher than model estimates for landscapes dominated by oak (relatively low monoterpene emitting) trees. This results suggests that unaccounted processes, such as floral emissions or light dependent monoterpene emissions, or

Airborne measurements of isoprene and monoterpene emissions from southeastern U.S. forests

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Haofei; Guenther, Alex; Gu, Dasa

Isoprene and monoterpene emission rates are essential inputs for atmospheric chemistry models that simulate atmospheric oxidant and particle distributions. Process studies of the biochemical and physiological mechanisms controlling these emissions are advancing our understanding and the accuracy of model predictions but efforts to quantify regional emissions have been limited by a lack of constraints on regional distributions of ecosystem emission capacities. We used an airborne wavelet-based eddy covariance measurement technique to characterize isoprene and monoterpene fluxes with high spatial resolution during the 2013 SAS (Southeast Atmosphere Study) in the southeastern United States. The fluxes measured by direct eddy covariance weremore » comparable to emissions independently estimated using an indirect inverse modeling approach. Isoprene emission factors based on the aircraft wavelet flux estimates for high isoprene chemotypes (e.g., oaks) were similar to the MEGAN2.1 biogenic emission model estimates for landscapes dominated by oaks. Aircraft flux measurement estimates for landscapes with fewer isoprene emitting trees (e.g., pine plantations), were about a factor of two lower than MEGAN2.1 model estimates. The tendency for high isoprene emitters in these landscapes to occur in the shaded understory, where light dependent isoprene emissions are diminished, may explain the lower than expected emissions. This result demonstrates the importance of accurately representing the vertical profile of isoprene emitting biomass in biogenic emission models. Airborne measurement-based emission factors for high monoterpene chemotypes agreed with MEGAN2.1 in landscapes dominated by pine (high monoterpene chemotype) trees but were more than a factor of three higher than model estimates for landscapes dominated by oak (relatively low monoterpene emitting) trees. This results suggests that unaccounted processes, such as floral emissions or light dependent monoterpene

In Situ Measurements of Sulfur Hexafluoride (SF6) and age of air from NH sources during the Atmospheric Tomography (ATom) global airborne survey

NASA Astrophysics Data System (ADS)

Elkins, J. W.; Moore, F. L.; Hintsa, E. J.; Ray, E. A.; Dutton, G. S.; Nance, J. D.; Hall, B. D.; Dlugokencky, E. J.; Sweeney, C.; Montzka, S. A.; Newman, P. A.

2017-12-01

Atmospheric SF6 is an excellent tracer of atmospheric transport in the troposphere, because of its long lifetime (850 years), mostly northern hemispheric (NH) emissions (95%), and high atmospheric growth rate ( 4%/yr.). The gas is used in the distribution of electrical power, because it is an excellent insulator. It is primarily released through its use (leaking and refilling) in high voltage power transformers. Two NOAA/GMD airborne, in situ gas chromatographs (GCs), PAN and other Trace Hydrohalocarbons ExpeRiment (PANTHER) and UAS Chromatograph for Atmospheric Trace Species (UCATS), operated on the first two circuits of the Atmospheric Tomography Mission (ATom-1 & ATom-2). Both instruments measure nitrous oxide (N2O) and sulfur hexafluoride (SF6) once every 70 seconds using a very sensitive electron capture detector (ECD). We combined both measurements into one data set for analysis of twice the amount of data, since both instruments are comparable and used the same gas standards. The main purpose of ATom is to study the influence of air quality on climate during the four seasons, where two seasons are completed so far. The altitude-latitude cross sections of SF6 mixing ratios during the ATom-1 (left) shows sources are mostly located in the NH ( 95%). The upper troposphere shows inter-hemispheric mixing. The polar stratosphere shows older air that is mixed with air from the mesospheric sink. Using the procedure described by Waugh et al., (2013) [JGR-Atmos. 10.1002/jgrd.50189] and a recent growth rate of 0.32 ppt yr-1, we have calculated the mean age of each SF6 measurement from its source at ground level in the NH (lat. range of 30-50°N). The contours of age (right) are in agreement with the mean inter-hemispheric exchange time (τNS) of 1.2 yr and higher ages in the polar stratosphere (2.5-3.0 yr).

Aircraft measurement of ozone turbulent flux in the atmospheric boundary layer

NASA Astrophysics Data System (ADS)

Affre, Ch.; Carrara, A.; Lefebre, F.; Druilhet, A.; Fontan, J.; Lopez, A.

In May 1995, the "Chimie-Creil 95" experiment was undertaken in the north of France. The field data are first used to validate the methodology for airborne measurement of ozone flux. A certain number of methodological problems due to the location of the fast ozone sensor inside the airplane are, furthermore discussed. The paper describes the instrumentation of the ARAT (Avion de Recherche Atmosphérique et de Télédétection), an atmospheric research and remote-sensing aircraft used to perform the airborne measurements, the area flown over, the meteorological conditions and boundary layer stability conditions. These aircraft measurements are then used to determine ozone deposition velocity and values are proposed for aerodynamic, bulk transfer coefficients (ozone and momentum). The paper also establishes the relationship between the normalised standard deviation and stability parameters ( z/ L) for ozone, temperature, humidity and vertical velocity. The laws obtained are then presented.

Comparison of Continuous Wave CO2 Doppler Lidar Calibration Using Earth Surface Targets in Laboratory and Airborne Measurements

NASA Technical Reports Server (NTRS)

Jarzembski, Maurice A.; Srivastava, Vandana

1999-01-01

Routine backscatter, beta, measurements by an airborne or space-based lidar from designated earth surfaces with known and fairly uniform beta properties can potentially offer lidar calibration opportunities. This can in turn be used to obtain accurate atmospheric aerosol and cloud beta measurements on large spatial scales. This is important because achieving a precise calibration factor for large pulsed lidars then need not rest solely on using a standard hard target procedure. Furthermore, calibration from designated earth surfaces would provide an inflight performance evaluation of the lidar. Hence, with active remote sensing using lasers with high resolution data, calibration of a space-based lidar using earth's surfaces will be extremely useful. The calibration methodology using the earth's surface initially requires measuring beta of various earth surfaces simulated in the laboratory using a focused continuous wave (CW) CO2 Doppler lidar and then use these beta measurements as standards for the earth surface signal from airborne or space-based lidars. Since beta from the earth's surface may be retrieved at different angles of incidence, beta would also need to be measured at various angles of incidences of the different surfaces. In general, Earth-surface reflectance measurements have been made in the infrared, but the use of lidars to characterize them and in turn use of the Earth's surface to calibrate lidars has not been made. The feasibility of this calibration methodology is demonstrated through a comparison of these laboratory measurements with actual earth surface beta retrieved from the same lidar during the NASA/Multi-center Airborne Coherent Atmospheric Wind Sensor (MACAWS) mission on NASA's DC8 aircraft from 13 - 26 September, 1995. For the selected earth surface from the airborne lidar data, an average beta for the surface was established and the statistics of lidar efficiency was determined. This was compared with the actual lidar efficiency

Wind Field Measurements With Airborne Doppler Lidar

NASA Technical Reports Server (NTRS)

Menzies, Robert T.

1999-01-01

In collaboration with lidar atmospheric remote sensing groups at NASA Marshall Space Flight Center and National Oceanic and Atmospheric Administration (NOAA) Environmental Technology Laboratory, we have developed and flown the Multi-center Airborne Coherent Atmospheric Wind Sensor (MACAWS) lidar on the NASA DC-8 research aircraft. The scientific motivations for this effort are: to obtain measurements of subgrid scale (i.e. 2-200 km) processes and features which may be used to improve parameterizations in global/regional-scale models; to improve understanding and predictive capabilities on the mesoscale; and to assess the performance of Earth-orbiting Doppler lidar for global tropospheric wind measurements. MACAWS is a scanning Doppler lidar using a pulsed transmitter and coherent detection; the use of the scanner allows 3-D wind fields to be produced from the data. The instrument can also be radiometrically calibrated and used to study aerosol, cloud, and surface scattering characteristics at the lidar wavelength in the thermal infrared. MACAWS was used to study surface winds off the California coast near Point Arena, with an example depicted in the figure below. The northerly flow here is due to the Pacific subtropical high. The coastal topography interacts with the northerly flow in the marine inversion layer, and when the flow passes a cape or point that juts into the winds, structures called "hydraulic expansion fans" are observed. These are marked by strong variation along the vertical and cross-shore directions. The plots below show three horizontal slices at different heights above sea level (ASL). Bottom plots are enlargements of the area marked by dotted boxes above. The terrain contours are in 200-m increments, with the white spots being above 600-m elevation. Additional information is contained in the original.

Ground and Airborne Methane Measurements Using Optical Parametric Amplifiers

NASA Technical Reports Server (NTRS)

Numata, Kenji; Riris, Haris; Li, Steve; Wu, Stewart; Kawa, Stephan R.; Abshire, James Brice; Dawsey, Martha; Ramanathan, Anand

2011-01-01

We report on ground and airborne methane measurements with an active sensing instrument using widely tunable, seeded optical parametric generation (OPG). The technique has been used to measure methane, CO2, water vapor, and other trace gases in the near and mid-infrared spectral regions. Methane is a strong greenhouse gas on Earth and it is also a potential biogenic marker on Mars and other planetary bodies. Methane in the Earth's atmosphere survives for a shorter time than CO2 but its impact on climate change can be larger than CO2. Carbon and methane emissions from land are expected to increase as permafrost melts exposing millennial-age carbon stocks to respiration (aerobic-CO2 and anaerobic-CH4) and fires. Methane emissions from c1athrates in the Arctic Ocean and on land are also likely to respond to climate warming. However, there is considerable uncertainty in present Arctic flux levels, as well as how fluxes will change with the changing environment. For Mars, methane measurements are of great interest because of its potential as a strong biogenic marker. A remote sensing instrument that can measure day and night over all seasons and latitudes can localize sources of biogenic gas plumes produced by subsurface chemistry or biology, and aid in the search for extra-terrestrial life. In this paper we report on remote sensing measurements of methane using a high peak power, widely tunable optical parametric generator (OPG) operating at 3.3 micrometers and 1.65 micrometers. We have demonstrated detection of methane at 3.3 micrometers and 1650 nanometers in an open path and compared them to accepted standards. We also report on preliminary airborne demonstration of methane measurements at 1.65 micrometers.

Ice crystals classification using airborne measurements in mixing phase

NASA Astrophysics Data System (ADS)

Sorin Vajaiac, Nicolae; Boscornea, Andreea

2017-04-01

This paper presents a case study of ice crystals classification from airborne measurements in mixed-phase clouds. Ice crystal shadow is recorded with CIP (Cloud Imaging Probe) component of CAPS (Cloud, Aerosol, and Precipitation Spectrometer) system. The analyzed flight was performed in the south-western part of Romania (between Pietrosani, Ramnicu Valcea, Craiova and Targu Jiu), with a Beechcraft C90 GTX which was specially equipped with a CAPS system. The temperature, during the fly, reached the lowest value at -35 °C. These low temperatures allow the formation of ice crystals and influence their form. For the here presented ice crystals classification a special software, OASIS (Optical Array Shadow Imaging Software), developed by DMT (Droplet Measurement Technologies), was used. The obtained results, as expected are influenced by the atmospheric and microphysical parameters. The particles recorded where classified in four groups: edge, irregular, round and small.

Atmospheric methane over Siberia: measurements from the 2014 YAK-AEROSIB aircraft campaign

NASA Astrophysics Data System (ADS)

Paris, Jean-Daniel; Pisso, Ignacio; Ancellet, Gérard; Law, Kathy; Arshinov, Mikhail Yu.; Belan, Boris D.; Nédélec, Philippe; Myhre, Cathrine Lund

2017-04-01

The YAK-AEROSIB program collects high-precision in-situ measurements of the vertical distribution of CO2, CH4, CO, O3, black carbon and ultrafine particles distribution in the Siberian troposphere, as well as other parameters including aerosol lidar profiles, on a pan-Siberian aircraft transect. Recent efforts aim at better understanding the respective role of CH4 emission processes in driving its large scale atmospheric variability over the region. The October 2014 YAK-AEROSIB/MOCA campaign from Novosibirsk to Salekhard and over the Kara sea and the Yamal peninsula sampled air masses affected by local, regional and remote pollution. We analyse the contribution of local anthropogenic sources to measured CH4 enhancements, in relation to atmospheric mixing and transport conditions. Our analysis also attempts to detect CH4 signal from sources of methane in the Siberian shelf and the Arctic ocean during low level flight legs over the Kara sea using the airborne measurements and a Lagrangian model coupled to potential CH4 hydrate and geological sources. The measured CH4 concentrations do not contradict a potential source upstream of our measurements, but the interpretation is challenging due to a very low CH4 signal. The challenging question of the methane budget and its evolution in Siberia leads to a need for new approaches. A new generation of airborne measurements, more flexible, is now needed.

Low Permafrost Methane Emissions from Arctic Airborne Flux Measurements

NASA Astrophysics Data System (ADS)

Sachs, T.; Serafimovich, A.; Metzger, S.; Kohnert, K.; Hartmann, J.

2014-12-01

One of the most pressing questions with regard to climate feedback processes in a warming Arctic is the regional-scale greenhouse gas release from Arctic permafrost areas. Ground-based eddy covariance (EC) measurements provide continuous in-situ observations of the surface-atmosphere exchange of energy and matter. However, these observations are rare in the Arctic permafrost zone and site selection is bound by logistical constraints among others. Consequently, these observations cover only small areas that are not necessarily representative of the region of interest. Airborne measurements can overcome this limitation by covering distances of hundreds of kilometers over time periods of a few hours. The Airborne Measurements of Methane Fluxes (AIRMETH) campaigns are designed to quantitatively and spatially explicitly address this question. During the AIRMETH-2012 and AIRMETH-2013 campaigns aboard the research aircraft POLAR 5 we measured turbulent exchange of energy, methane, and (in 2013) carbon dioxide along thousands of kilometers covering the North Slope of Alaska and the Mackenzie Delta, Canada. Time-frequency (wavelet) analysis, footprint modeling, and machine learning techniques are used to (i) determine spatially resolved turbulence statistics, fluxes, and contributions of biophysical surface properties, and (ii) extract regionally valid functional relationships between environmental drivers and the observed fluxes. These environmental response functions (ERF) are used to explain spatial flux patterns and - if drivers are available in temporal resolution - allow for spatio-temporal scaling of the observations. This presentation will focus on 2012 methane fluxes on the North Slope of Alaska and the relevant processes on the regional scale and provide an updated 100 m resolution methane flux map of the North Slope of Alaska.

Global Airborne Observations of Nitrogen Oxides and Ozone from the Atmospheric Tomography Mission

NASA Astrophysics Data System (ADS)

Thompson, C. R.; Peischl, J.; Ryerson, T. B.

2016-12-01

The Atmospheric Tomography (ATom) Mission is an ambitious airborne field campaign that will conduct measurements of an extensive suite of trace gases and aerosols from the NASA DC-8 platform over three years and four seasons. Flights will travel nearly pole-to-pole, traversing both the Pacific and Atlantic Oceans, while profiling continuously from 0.2 to 12 km altitude to provide nearly global-scale observations of greenhouse gases and reactive species. Measurements from ATom will provide an unprecedented test for current global chemistry-climate models (CCMs) and will inform further improvements to these models. In particular, reactive species, such as ozone, are difficult to represent accurately in CCMs. We will present global observations of reactive nitrogen compounds (NO, NO2, NOy) and ozone from the first deployment of the ATom Mission in August of 2016. Flights will intercept a wide variety of air masses with different pollution signatures, including aged biomass burning emissions from Siberian wildfires and anthropogenic outflow from the Asian mainland, which will contrast the relatively clean background atmosphere encountered in the high latitudes of the Northern and Southern Hemispheres. We will compare the composition of the NOy budgets across these variety of air masses and impacts on ozone.

Campaign datasets for ARM Airborne Carbon Measurements (ARM-ACME-V)

DOE Data Explorer

Biraud,Sebastien; Mei,Fan; Flynn,Connor; Hubbe,John; Long,Chuck; Matthews,Alyssa; Pekour,Mikhail; Sedlacek,Arthur; Springston,Stephen; Tomlinson,Jason; Chand,Duli

2016-03-15

Atmospheric temperatures are warming faster in the Arctic than predicted by climate models. The impact of this warming on permafrost degradation is not well understood, but it is projected to increase carbon decomposition and greenhouse gas production (CO2 and/or CH4) by arctic ecosystems. Airborne observations of atmospheric trace gases, aerosols, and cloud properties at the North Slope of Alaska are improving our understanding of global climate, with the goal of reducing the uncertainty in global and regional climate simulations and projections.

Characterization of Airborne Microbial Communities at a High-Elevation Site and Their Potential To Act as Atmospheric Ice Nuclei▿

PubMed Central

Bowers, Robert M.; Lauber, Christian L.; Wiedinmyer, Christine; Hamady, Micah; Hallar, Anna G.; Fall, Ray; Knight, Rob; Fierer, Noah

2009-01-01

Bacteria and fungi are ubiquitous in the atmosphere. The diversity and abundance of airborne microbes may be strongly influenced by atmospheric conditions or even influence atmospheric conditions themselves by acting as ice nucleators. However, few comprehensive studies have described the diversity and dynamics of airborne bacteria and fungi based on culture-independent techniques. We document atmospheric microbial abundance, community composition, and ice nucleation at a high-elevation site in northwestern Colorado. We used a standard small-subunit rRNA gene Sanger sequencing approach for total microbial community analysis and a bacteria-specific 16S rRNA bar-coded pyrosequencing approach (4,864 sequences total). During the 2-week collection period, total microbial abundances were relatively constant, ranging from 9.6 × 105 to 6.6 × 106 cells m−3 of air, and the diversity and composition of the airborne microbial communities were also relatively static. Bacteria and fungi were nearly equivalent, and members of the proteobacterial groups Burkholderiales and Moraxellaceae (particularly the genus Psychrobacter) were dominant. These taxa were not always the most abundant in freshly fallen snow samples collected at this site. Although there was minimal variability in microbial abundances and composition within the atmosphere, the number of biological ice nuclei increased significantly during periods of high relative humidity. However, these changes in ice nuclei numbers were not associated with changes in the relative abundances of the most commonly studied ice-nucleating bacteria. PMID:19502432

Airborne High Spectral Resolution Lidar Aerosol Measurements during MILAGRO and TEXAQS/GOMACCS

NASA Technical Reports Server (NTRS)

Ferrare, Richard; Hostetler, Chris; Hair, John; Cook Anthony; Harper, David; Burton, Sharon; Clayton, Marian; Clarke, Antony; Russell, Phil; Redemann, Jens

2007-01-01

Two1 field experiments conducted during 2006 provided opportunities to investigate the variability of aerosol properties near cities and the impacts of these aerosols on air quality and radiative transfer. The Megacity Initiative: Local and Global Research Observations (MILAGRO) /Megacity Aerosol Experiment in Mexico City (MAX-MEX)/Intercontinental Chemical Transport Experiment-B (INTEX-B) joint experiment conducted during March 2006 investigated the evolution and transport of pollution from Mexico City. The Texas Air Quality Study (TEXAQS)/Gulf of Mexico Atmospheric Composition and Climate Study (GoMACCS) (http://www.al.noaa.gov/2006/) conducted during August and September 2006 investigated climate and air quality in the Houston/Gulf of Mexico region. During both missions, the new NASA Langley airborne High Spectral Resolution Lidar (HSRL) was deployed on the NASA Langley B200 King Air aircraft and measured profiles of aerosol extinction, backscattering, and depolarization to: 1) characterize the spatial and vertical distributions of aerosols, 2) quantify aerosol extinction and optical thickness contributed by various aerosol types, 3) investigate aerosol variability near clouds, 4) evaluate model simulations of aerosol transport, and 5) assess aerosol optical properties derived from a combination of surface, airborne, and satellite measurements.

Airborne gamma radiation soil moisture measurements over short flight lines

NASA Technical Reports Server (NTRS)

Peck, Eugene L.; Carrol, Thomas R.; Lipinski, Daniel M.

1990-01-01

Results are presented on airborne gamma radiation measurements of soil moisture condition, carried out along short flight lines as part of the First International Satellite Land Surface Climatology Project Field Experiment (FIFE). Data were collected over an area in Kansas during the summers of 1987 and 1989. The airborne surveys, together with ground measurements, provide the most comprehensive set of airborne and ground truth data available in the U.S. for calibrating and evaluating airborne gamma flight lines. Analysis showed that, using standard National Weather Service weights for the K, Tl, and Gc radiation windows, the airborne soil moisture estimates for the FIFE lines had a root mean square error of no greater than 3.0 percent soil moisture. The soil moisture estimates for sections having acquisition time of at least 15 sec were found to be reliable.

NASA COAST and OCEANIA Airborne Missions in Support of Ecosystem and Water Quality Research in the Coastal Zone

NASA Technical Reports Server (NTRS)

Guild, Liane S.; Hooker, Stanford B.; Kudela, Raphael; Morrow, John; Russell, Philip; Myers, Jeffrey; Dunagan, Stephen; Palacios, Sherry; Livingston, John; Negrey, Kendra;

NASA COAST and OCEANIA Airborne Missions Support Ecosystem and Water Quality Research in the Coastal Zone

NASA Technical Reports Server (NTRS)

Guild, Liane; Kudela, Raphael; Hooker, Stanford; Morrow, John; Russell, Philip; Palacios, Sherry; Livingston, John M.; Negrey, Kendra; Torres-Perez, Juan; Broughton, Jennifer

2014-01-01

NASA has a continuing requirement to collect high-quality in situ data for the vicarious calibration of current and next generation ocean color satellite sensors and to validate the algorithms that use the remotely sensed observations. Recent NASA airborne missions over Monterey Bay, CA, have demonstrated novel above- and in-water measurement capabilities supporting a combined airborne sensor approach (imaging spectrometer, microradiometers, and a sun photometer). The results characterize coastal atmospheric and aquatic properties through an end-to-end assessment of image acquisition, atmospheric correction, algorithm application, plus sea-truth observations from state-of-the-art instrument systems. The primary goal is to demonstrate the following in support of calibration and validation exercises for satellite coastal ocean color products: 1) the utility of a multi-sensor airborne instrument suite to assess the bio-optical properties of coastal California, including water quality; and 2) the importance of contemporaneous atmospheric measurements to improve atmospheric correction in the coastal zone. The imaging spectrometer (Headwall) is optimized in the blue spectral domain to emphasize remote sensing of marine and freshwater ecosystems. The novel airborne instrument, Coastal Airborne In-situ Radiometers (C-AIR) provides measurements of apparent optical properties with high dynamic range and fidelity for deriving exact water leaving radiances at the land-ocean boundary, including radiometrically shallow aquatic ecosystems. Simultaneous measurements supporting empirical atmospheric correction of image data are accomplished using the Ames Airborne Tracking Sunphotometer (AATS-14). Flight operations are presented for the instrument payloads using the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) Twin Otter flown over Monterey Bay during the seasonal fall algal bloom in 2011 (COAST) and 2013 (OCEANIA) to support bio-optical measurements of

The SPIRIT airborne instrument: a three-channel infrared absorption spectrometer with quantum cascade lasers for in situ atmospheric trace-gas measurements

NASA Astrophysics Data System (ADS)

Catoire, Valéry; Robert, Claude; Chartier, Michel; Jacquet, Patrick; Guimbaud, Christophe; Krysztofiak, Gisèle

2017-09-01

An infrared absorption spectrometer called SPIRIT (SPectromètre Infra-Rouge In situ Toute altitude) has been developed for airborne measurements of trace gases in the troposphere. At least three different trace gases can be measured simultaneously every 1.6 s using the coupling of a single Robert multipass optical cell with three Quantum Cascade Lasers (QCLs), easily interchangeable to select species depending on the scientific objectives. Absorptions of the mid-infrared radiations by the species in the cell at reduced pressure (<40 hPa), with path lengths adjustable up to 167.78 m, are quantified using an HgCdTe photodetector cooled by Stirling cycle. The performances of the instrument are assessed: a linearity with a coefficient of determination R 2 > 0.979 for the instrument response is found for CO, CH4, and NO2 volume mixing ratios under typical tropospheric conditions. In-flight comparisons with calibrated gas mixtures allow to show no instrumental drift correlated with atmospheric pressure and temperature changes (when vertical profiling) and to estimate the overall uncertainties in the measurements of CO, CH4, and NO2 to be 0.9, 22, and 0.5 ppbv, respectively. In-flight precision (1 σ) for these species at 1.6 s sampling is 0.3, 5, and 0.3 ppbv, respectively.

Metagenomic characterization of airborne viral DNA diversity in the near-surface atmosphere.

PubMed

Whon, Tae Woong; Kim, Min-Soo; Roh, Seong Woon; Shin, Na-Ri; Lee, Hae-Won; Bae, Jin-Woo

2012-08-01

Airborne viruses are expected to be ubiquitous in the atmosphere but they still remain poorly understood. This study investigated the temporal and spatial dynamics of airborne viruses and their genotypic characteristics in air samples collected from three distinct land use types (a residential district [RD], a forest [FR], and an industrial complex [IC]) and from rainwater samples freshly precipitated at the RD site (RD-rain). Viral abundance exhibited a seasonal fluctuation in the range between 1.7 × 10(6) and 4.0 × 10(7) viruses m(-3), which increased from autumn to winter and decreased toward spring, but no significant spatial differences were observed. Temporal variations in viral abundance were inversely correlated with seasonal changes in temperature and absolute humidity. Metagenomic analysis of air viromes amplified by rolling-circle phi29 polymerase-based random hexamer priming indicated the dominance of plant-associated single-stranded DNA (ssDNA) geminivirus-related viruses, followed by animal-infecting circovirus-related sequences, with low numbers of nanoviruses and microphages-related genomes. Particularly, the majority of the geminivirus-related viruses were closely related to ssDNA mycoviruses that infect plant-pathogenic fungi. Phylogenetic analysis based on the replication initiator protein sequence indicated that the airborne ssDNA viruses were distantly related to known ssDNA viruses, suggesting that a high diversity of viruses were newly discovered. This research is the first to report the seasonality of airborne viruses and their genetic diversity, which enhances our understanding of viral ecology in temperate regions.

Metagenomic Characterization of Airborne Viral DNA Diversity in the Near-Surface Atmosphere

PubMed Central

Whon, Tae Woong; Kim, Min-Soo; Roh, Seong Woon; Shin, Na-Ri; Lee, Hae-Won

2012-01-01

Airborne viruses are expected to be ubiquitous in the atmosphere but they still remain poorly understood. This study investigated the temporal and spatial dynamics of airborne viruses and their genotypic characteristics in air samples collected from three distinct land use types (a residential district [RD], a forest [FR], and an industrial complex [IC]) and from rainwater samples freshly precipitated at the RD site (RD-rain). Viral abundance exhibited a seasonal fluctuation in the range between 1.7 × 106 and 4.0 × 107 viruses m−3, which increased from autumn to winter and decreased toward spring, but no significant spatial differences were observed. Temporal variations in viral abundance were inversely correlated with seasonal changes in temperature and absolute humidity. Metagenomic analysis of air viromes amplified by rolling-circle phi29 polymerase-based random hexamer priming indicated the dominance of plant-associated single-stranded DNA (ssDNA) geminivirus-related viruses, followed by animal-infecting circovirus-related sequences, with low numbers of nanoviruses and microphages-related genomes. Particularly, the majority of the geminivirus-related viruses were closely related to ssDNA mycoviruses that infect plant-pathogenic fungi. Phylogenetic analysis based on the replication initiator protein sequence indicated that the airborne ssDNA viruses were distantly related to known ssDNA viruses, suggesting that a high diversity of viruses were newly discovered. This research is the first to report the seasonality of airborne viruses and their genetic diversity, which enhances our understanding of viral ecology in temperate regions. PMID:22623790

Development of airborne eddy-correlation flux measurement capabilities for reactive oxides of nitrogen

NASA Technical Reports Server (NTRS)

Bradshaw, John (Principal Investigator); Zheng, Xiaonan; Sandholm, Scott T.

1996-01-01

This research is aimed at producing a fundamental new research tool for characterizing the source strength of the most important compound controlling the hemispheric and global scale distribution of tropospheric ozone. Specifically, this effort seeks to demonstrate the proof-of-concept of a new general purpose laser-induced fluorescence based spectrometer for making airborne eddy-correlation flux measurements of nitric oxide (NO) and other reactive nitrogen compounds. The new all solid-state laser technology being used in this advanced sensor will produce a forerunner of the type of sensor technology that should eventually result in highly compact operational systems. The proof-of-concept sensor being developed will have over two orders-of-magnitude greater sensitivity than present-day instruments. In addition, this sensor will offer the possibility of eventual extension to airborne eddy-correlation flux measurements of nitrogen dioxide (NO2) and possibly other compounds, such as ammonia (NH3), peroxyradicals (HO2), nitrateradicals (NO3) and several iodine compounds (e.g., I and IO). Demonstration of the new sensor's ability to measure NO fluxes will occur through a series of laboratory and field tests. This proof-of-concept demonstration will show that not only can airborne fluxes of important ultra-trace compounds be made at the few parts-per-trillion level, but that the high accuracy/precision measurements currently needed for predictive models can also. These measurement capabilities will greatly enhance our current ability to quantify the fluxes of reactive nitrogen into the troposphere and significantly impact upon the accuracy of predictive capabilities to model O3's distribution within the remote troposphere. This development effort also offers a timely approach for producing the reactive nitrogen flux measurement capabilities that will be needed by future research programs such as NASA's planned 1999 Amazon Biogeochemistry and Atmospheric Chemistry

Hurricane Wind Field Measurements with Scanning Airborne Doppler Lidar During CAMEX-3

NASA Technical Reports Server (NTRS)

Rothermel, Jeffry; Cutten, D. R.; Howell, J. N.; Darby, L. S.; Hardesty, R. M.; Traff, D. M.; Menzies, R. T.

2000-01-01

During the 1998 Convection and Moisture Experiment (CAMEX-3), the first hurricane wind field measurements with Doppler lidar were achieved. Wind fields were mapped within the eye, along the eyewall, in the central dense overcast, and in the marine boundary layer encompassing the inflow region. Spatial coverage was determined primarily by cloud distribution and opacity. Within optically-thin cirrus slant range of 20- 25 km was achieved, whereas no propagation was obtained during penetration of dense cloud. Measurements were obtained with the Multi-center Airborne Coherent Atmospheric Wind Sensor (MACAWS) on the NASA DC-8 research aircraft. MACAWS was developed and operated cooperatively by the atmospheric lidar remote sensing groups of NOAA Environmental Technology Laboratory, NASA Marshall Space Flight Center, and Jet Propulsion Laboratory. A pseudo-dual Doppler technique ("co-planar scanning") is used to map the horizontal component of the wind at several vertical levels. Pulses from the laser are directed out the left side of the aircraft in the desired directions using computer-controlled rotating prisms. Upon exiting the aircraft, the beam is completely eyesafe. Aircraft attitude and speed are taken into account during real-time signal processing, resulting in determination of the ground-relative wind to an accuracy of about 1 m/s magnitude and about 10 deg direction. Beam pointing angle errors are about 0.1 deg, equivalent to about 17 m at 10 km. Horizontal resolution is about 1 km (along-track) for typical signal processor and scanner settings; vertical resolution varies with range. Results from CAMEX-3 suggest that scanning Doppler wind lidar can complement airborne Doppler radar by providing wind field measurements in regions that are devoid of hydrometeors. At present MACAWS observations are being assimilated into experimental forecast models and satellite Doppler wind lidar simulations to evaluate the relative impact.

Combining Airborne and Lidar Measurements for Attribution of Aerosol Layers

NASA Astrophysics Data System (ADS)

Nikandrova, A.; Väänänen, R.; Tabakova, K.; Kerminen, V. M.; O'Connor, E.

2016-12-01

The aim of this work was to identify discrete aerosol layers and diagnose their origin, investigate the strength of mixing within the free-troposphere and with the boundary layer (BL), and understand the impact that mixing has on local and long-range transport of aerosol. For these purposes we combined airborne in-situ aerosol measurements with data obtained by a High Spectral Resolution Lidar (HSRL). The HSRL was deployed in Hyytiälä, Southern Finland, from January to September 2014 as a part of the US DoE ARM (Atmospheric Radiation Measurement) Mobile Facility during the BAECC (Biogenic Aerosols - Effects on Cloud and Climate) Campaign. Two airborne campaigns took place in April and August 2014 during the BAECC campaign. The vertical profile of backscatter coefficient from the HSRL was used to diagnose the location and depth of significant aerosol layers in the atmosphere. Frequently, in addition to the BL, one or two tropospheric layers were identified. In-situ measurements of the aerosol size distribution in these layers were obtained from a Scanning Mobility Particle Sizer (SMPS) and Optical Particle Sizer (OPS), that were installed on board the aircraft; these measurements were combined to cover sizes ranging from 10 nm to 10 µm. As expected, the highest number concentration of aerosol particles at all size ranges was found predominantly in the BL. Many upper layers had size distributions with a similar shape to that in the BL but with overall lower concentrations attributed to dilution of particles into a large volume of air. Hence, these layers were likely of very similar origin to the air in the BL and presumably were the result of lofted residual layers. Intervening layers however, could contain markedly different distribution shapes, which could be attributed to both different air mass origins, and different ambient relative humidity. Potential for mixing between two discreet elevated layers was often seen as a thin interface layer, which exhibited a

Atmospheric water mapping with the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS), Mountain Pass, California

NASA Technical Reports Server (NTRS)

Conel, James E.; Green, Robert O.; Carrere, Veronique; Margolis, Jack S.; Alley, Ronald E.; Vane, Gregg; Bruegge, Carol J.; Gary, Bruce L.

1988-01-01

Observations are given of the spatial variation of atmospheric precipitable water using the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) over a desert area in eastern California, derived using a band ratio method and the 940 nm atmospheric water band and 870 nm continuum radiances. The ratios yield total path water from curves of growth supplied by the LOWTRAN 7 atmospheric model. An independent validation of the AVIRIS-derived column abundance at a point is supplied by a spectral hygrometer calibrated with respect to radiosonde observations. Water values conform to topography and fall off with surface elevation. The edge of the water vapor boundary layer defined by topography is thought to have been recovered. The ratio method yields column abundance estimates of good precision and high spatial resolution.

Aerosol Optical Depth Measurements by Airborne Sun Photometer in SOLVE II: Comparisons to SAGE III, POAM III and Airborne Spectrometer Measurements

NASA Technical Reports Server (NTRS)

Russell, P.; Livingston, J.; Schmid, B.; Eilers, J.; Kolyer, R.; Redemann, J.; Ramirez, S.; Yee, J-H.; Swartz, W.; Shetter, R.

2004-01-01

The 14-channel NASA Ames Airborne Tracking Sunphotometer (AATS-14) measured solar-beam transmission on the NASA DC-8 during the Second SAGE III Ozone Loss and Validation Experiment (SOLVE II). This paper presents AATS-14 results for multiwavelength aerosol optical depth (AOD), including its spatial structure and comparisons to results from two satellite sensors and another DC-8 instrument. These are the Stratospheric Aerosol and Gas Experiment III (SAGE III), the Polar Ozone and Aerosol Measurement III (POAM III) and the Direct beam Irradiance Airborne Spectrometer (DIAS).

The Atmospheric Radiation Measurement Program May 2003 Intensive Operations Period Examining Aerosol Properties and Radiative Influences: Preface to Special Section

NASA Technical Reports Server (NTRS)

Ferrare, Richard; Feingold, Graham; Ghan, Steven; Ogren, John; Schmid, Beat; Schwartz, Stephen E.; Sheridan, Pat

2006-01-01

Atmospheric aerosols influence climate by scattering and absorbing radiation in clear air (direct effects) and by serving as cloud condensation nuclei, modifying the microphysical properties of clouds, influencing radiation and precipitation development (indirect effects). Much of present uncertainty in forcing of climate change is due to uncertainty in the relations between aerosol microphysical and optical properties and their radiative influences (direct effects) and between microphysical properties and their ability to serve as cloud condensation nuclei at given supersaturations (indirect effects). This paper introduces a special section that reports on a field campaign conducted at the Department of Energy Atmospheric Radiation Measurement site in North Central Oklahoma in May, 2003, examining these relations using in situ airborne measurements and surface-, airborne-, and space-based remote sensing.

Airborne Sunphotometer Studies of Aerosol Properties and Effects, Including Closure Among Satellite, Suborbital Remote, and In situ Measurements

NASA Technical Reports Server (NTRS)

Russlee, Philip B.; Schmid, B.; Redemann, J.; Livingston, J. M.; Bergstrom, R. W.; Ramirez, S. A.; Hipskind, R. Stephen (Technical Monitor)

2001-01-01

Airborne sunphotometry has been used to measure aerosols from North America, Europe, and Africa in coordination with satellite and in situ measurements in TARFOX (1996), ACE-2 (1997), PRIDE (2000), and SAFARI 2000. Similar coordinated measurements of Asian aerosols are being conducted this spring in ACE-Asia and are planned for North American aerosols this summer in CLAMS. This paper summarizes the approaches used, key results, and implications for aerosol properties and effects, such as single scattering albedo and regional radiative forcing. The approaches exploit the three-dimensional mobility of airborne sunphotometry to access satellite scenes over diverse surfaces (including open ocean with and without sunglint) and to match exactly the atmospheric layers sampled by airborne in situ measurements and other radiometers. These measurements permit tests of the consistency, or closure, among such diverse measurements as aerosol size-resolved chemical composition; number or mass concentration; light extinction, absorption, and scattering (total, hemispheric back and 180 deg.); and radiative fluxes. In this way the airborne sunphotometer measurements provide a key link between satellite and in situ measurements that helps to understand any discrepancies that are found. These comparisons have led to several characteristic results. Typically these include: (1) Better agreement among different types of remote measurements than between remote and in situ measurements. (2) More extinction derived from transmission measurements than from in situ measurements. (3) Larger aerosol absorption inferred from flux radiometry than from in situ measurements. Aerosol intensive properties derived from these closure studies have been combined with satellite-retrieved fields of optical depth to produce fields of regional radiative forcing. We show results for the North Atlantic derived from AVHRR optical depths and aerosol intensive properties from TARFOX and ACE-2. Companion papers

Pressure Measurements Using an Airborne Differential Absorption Lidar. Part 1; Analysis of the Systematic Error Sources

NASA Technical Reports Server (NTRS)

Flamant, Cyrille N.; Schwemmer, Geary K.; Korb, C. Laurence; Evans, Keith D.; Palm, Stephen P.

1999-01-01

Remote airborne measurements of the vertical and horizontal structure of the atmospheric pressure field in the lower troposphere are made with an oxygen differential absorption lidar (DIAL). A detailed analysis of this measurement technique is provided which includes corrections for imprecise knowledge of the detector background level, the oxygen absorption fine parameters, and variations in the laser output energy. In addition, we analyze other possible sources of systematic errors including spectral effects related to aerosol and molecular scattering interference by rotational Raman scattering and interference by isotopic oxygen fines.

NASA's Student Airborne Research Program (2009-2013)

NASA Astrophysics Data System (ADS)

Schaller, E. L.; Shetter, R. E.

2013-12-01

The NASA Student Airborne Research Program (SARP) is a unique summer internship program for rising senior undergraduates majoring in any of the STEM disciplines. SARP participants acquire hands-on research experience in all aspects of an airborne research campaign, including flying onboard an major NASA resource used for studying Earth system processes. In summer 2013, thirty-two participants worked in four interdisciplinary teams to study surface, atmospheric, and oceanographic processes. Participants assisted in the operation of instruments onboard the NASA DC-8 aircraft where they sampled and measured atmospheric gases and imaged land and water surfaces in multiple spectral bands. Along with airborne data collection, students participated in taking measurements at field sites. Mission faculty and research mentors helped to guide participants through instrument operation, sample analysis, and data reduction. Over the eight-week program, each student developed an individual research project from the data collected and delivered a conference-style final presentation on his/her results. Several students will present the results of their research in science sessions at this meeting. We will discuss the results and effectiveness of the program over the past five summers and plans for the future.

High-resolution airborne imaging DOAS measurements of NO2 above Bucharest during AROMAT

NASA Astrophysics Data System (ADS)

Meier, Andreas Carlos; Schönhardt, Anja; Bösch, Tim; Richter, Andreas; Seyler, André; Ruhtz, Thomas; Constantin, Daniel-Eduard; Shaiganfar, Reza; Wagner, Thomas; Merlaud, Alexis; Van Roozendael, Michel; Belegante, Livio; Nicolae, Doina; Georgescu, Lucian; Burrows, John Philip

2017-05-01

In this study we report on airborne imaging DOAS measurements of NO2 from two flights performed in Bucharest during the AROMAT campaign (Airborne ROmanian Measurements of Aerosols and Trace gases) in September 2014. These measurements were performed with the Airborne imaging Differential Optical Absorption Spectroscopy (DOAS) instrument for Measurements of Atmospheric Pollution (AirMAP) and provide nearly gapless maps of column densities of NO2 below the aircraft with a high spatial resolution of better than 100 m. The air mass factors, which are needed to convert the measured differential slant column densities (dSCDs) to vertical column densities (VCDs), have a strong dependence on the surface reflectance, which has to be accounted for in the retrieval. This is especially important for measurements above urban areas, where the surface properties vary strongly. As the instrument is not radiometrically calibrated, we have developed a method to derive the surface reflectance from intensities measured by AirMAP. This method is based on radiative transfer calculation with SCIATRAN and a reference area for which the surface reflectance is known. While surface properties are clearly apparent in the NO2 dSCD results, this effect is successfully corrected for in the VCD results. Furthermore, we investigate the influence of aerosols on the retrieval for a variety of aerosol profiles that were measured in the context of the AROMAT campaigns. The results of two research flights are presented, which reveal distinct horizontal distribution patterns and strong spatial gradients of NO2 across the city. Pollution levels range from background values in the outskirts located upwind of the city to about 4 × 1016 molec cm-2 in the polluted city center. Validation against two co-located mobile car-DOAS measurements yields good agreement between the datasets, with correlation coefficients of R = 0.94 and R = 0.85, respectively. Estimations on the NOx

Coordinated analysis of various auroral measurements made during NASA's 1968 and 1969 airborne auroral expeditions

NASA Technical Reports Server (NTRS)

Sivjee, G. G.

1976-01-01

Auroral optical measurements made aboard NASA's CV 990 were analyzed. The measurements analyzed form a small part of extensive spectroscopic, photometric and photographic data gathered during the 1968 and 1969 Airborne Auroral Expeditions. Simultaneous particle measurements from ESRO IA satellite were used in the analysis. Information about magnetospheric boundaries, interaction between magnetosheath particles and the terrestrial ionosphere, the polar bulge in helium abundance and excitation mechanisms of the triplet state of atmospheric N2 in auroras was obtained. Further analysis of the data is required to elucidate the relation between 3466 and 5200 A emissions of NI and the excitation of 3726-3729 A emissions from atomic oxygen ions in auroras.

Airborne Mission Concept for Coastal Ocean Color and Ecosystems Research

NASA Technical Reports Server (NTRS)

Guild, Liane S.; Hooker, Stanford B.; Morrow, John H.; Kudela, Raphael M.; Palacios, Sherry L.; Torres Perez, Juan L.; Hayashi, Kendra; Dunagan, Stephen E.

2016-01-01

NASA airborne missions in 2011 and 2013 over Monterey Bay, CA, demonstrated novel above- and in-water calibration and validation measurements supporting a combined airborne sensor approach (imaging spectrometer, microradiometers, and a sun photometer). The resultant airborne data characterize contemporaneous coastal atmospheric and aquatic properties plus sea-truth observations from state-of-the-art instrument systems spanning a next-generation spectral domain (320-875 nm). This airborne instrument suite for calibration, validation, and research flew at the lowest safe altitude (ca. 100 ft or 30 m) as well as higher altitudes (e.g., 6,000 ft or 1,800 m) above the sea surface covering a larger area in a single synoptic sortie than ship-based measurements at a few stations during the same sampling period. Data collection of coincident atmospheric and aquatic properties near the sea surface and at altitude allows the input of relevant variables into atmospheric correction schemes to improve the output of corrected imaging spectrometer data. Specific channels support legacy and next-generation satellite capabilities, and flights are planned to within 30 min of satellite overpass. This concept supports calibration and validation activities of ocean color phenomena (e.g., river plumes, algal blooms) and studies of water quality and coastal ecosystems. The 2011 COAST mission flew at 100 and 6,000 ft on a Twin Otter platform with flight plans accommodating the competing requirements of the sensor suite, which included the Coastal-Airborne In-situ Radiometers (C-AIR) for the first time. C-AIR (Biospherical Instruments Inc.) also flew in the 2013 OCEANIA mission at 100 and 1,000 ft on the Twin Otter below the California airborne simulation of the proposed NASA HyspIRI satellite system comprised of an imaging spectrometer and thermal infrared multispectral imager on the ER-2 at 65,000 ft (20,000 m). For both missions, the Compact-Optical Profiling System (Biospherical

Airborne Quercus pollen in SW Spain: Identifying favourable conditions for atmospheric transport and potential source areas.

PubMed

Maya-Manzano, José María; Fernández-Rodríguez, Santiago; Smith, Matt; Tormo-Molina, Rafael; Reynolds, Andrew M; Silva-Palacios, Inmaculada; Gonzalo-Garijo, Ángela; Sadyś, Magdalena

2016-11-15

The pollen grains of Quercus spp. (oak trees) are allergenic. This study investigates airborne Quercus pollen in SW Spain with the aim identifying favourable conditions for atmospheric transport and potential sources areas. Two types of Quercus distribution maps were produced. Airborne Quercus pollen concentrations were measured at three sites located in the Extremadura region (SW Spain) for 3 consecutive years. The seasonal occurrence of Quercus pollen in the air was investigated, as well as days with pollen concentrations ≥80Pm(-3). The distance that Quercus pollen can be transported in appreciable numbers was calculated using clusters of back trajectories representing the air mass movement above the source areas (oak woodlands), and by using a state-of-the-art dispersion model. The two main potential sources of Quercus airborne pollen captured in SW Spain are Q. ilex subsp. ballota and Q. suber. The minimum distances between aerobiological stations and Quercus woodlands have been estimated as: 40km (Plasencia), 66km (Don Benito), 62km (Zafra) from the context of this study. Daily mean Quercus pollen concentration can exceed 1,700Pm(-3), levels reached not less than 24 days in a single year. High Quercus pollen concentration were mostly associated with moderate wind speed events (6-10ms(-1)), whereas that a high wind speed (16-20ms(-1)) seems to be associated with low concentrations. Copyright © 2016 Elsevier B.V. All rights reserved.

Quantifying Sources and Sinks of Reactive Gases in the Lower Atmosphere Using Airborne Flux Observations

NASA Technical Reports Server (NTRS)

Wolfe, G. M.; Hanisco, T. F.; Arkinson, H. L.; Bui, T. P.; Crounse, J. D.; Dean-Day, J.; Goldstein, A.; Guenther, A.; Hall, S. R.; Huey, G.;

Airborne gas chromatograph for in situ measurements of long-lived species in the upper troposphere and lower stratosphere

NASA Astrophysics Data System (ADS)

Elkins, J. W.; Fahey, D. W.; Gilligan, J. M.; Dutton, G. S.; Baring, T. J.; Volk, C. M.; Dunn, R. E.; Myers, R. C.; Montzka, S. A.; Wamsley, P. R.; Hayden, A. H.; Butler, J. H.; Thompson, T. M.; Swanson, T. H.; Dlugokencky, E. J.; Novelli, P. C.; Hurst, D. F.; Lobert, J. M.; Ciciora, S. J.; McLaughlin, R. J.; Thompson, T. L.; Winkler, R. H.; Fraser, P. J.; Steele, L. P.; Lucarelli, M. P.

A new instrument, the Airborne Chromatograph for Atmospheric Trace Species IV (ACATS-IV), for measuring long-lived species in the upper troposphere and lower stratosphere is described. Using an advanced approach to gas chromatography and electron capture detection, the instrument can detect low levels of CFC-11 (CCl3F), CFC-12 (CCl2F2), CFC-113 (CCl2F-CClF2), methyl chloroform (CH3CCl3), carbon tetrachloride (CCl4), nitrous oxide (N2O), sulfur hexafluoride (SF6), Halon-1211 (CBrClF2), hydrogen (H2), and methane (CH4) acquired in ambient samples every 180 or 360 s. The instrument operates fully-automated onboard the NASA ER-2 high-altitude aircraft on flights lasting up to 8 hours or more in duration. Recent measurements include 24 successful flights covering a broad latitude range (70°S-61°N) during the Airborne Southern Hemisphere Ozone Experiment/Measurements for Assessing the Effects of Stratospheric Aircraft (ASHOE/MAESA) campaign in 1994.

Passive remote sensing of large-scale methane emissions from Oil Fields in California's San Joaquin Valley and validation by airborne in-situ measurements - Results from COMEX

NASA Astrophysics Data System (ADS)

Gerilowski, Konstantin; Krautwurst, Sven; Thompson, David R.; Thorpe, Andrew K.; Kolyer, Richard W.; Jonsson, Haflidi; Krings, Thomas; Frankenberg, Christian; Horstjann, Markus; Leifer, Ira; Eastwood, Michael; Green, Robert O.; Vigil, Sam; Fladeland, Matthew; Schüttemeyer, Dirk; Burrows, John P.; Bovensmann, Heinrich

2016-04-01

The CO2 and MEthane EXperiment (COMEX) was a NASA and ESA funded campaign in support of the HyspIRI and CarbonSat mission definition activities. As a part of this effort, seven flights were performed between June 3 and September 4, 2014 with the Methane Airborne MAPper (MAMAP) remote sensing instrument (operated by the University of Bremen in cooperation with the German Research Centre for Geosciences - GFZ) over the Kern River, Kern Front, and Poso Creek Oil Fields located in California's San Joaquin Valley. MAMAP was installed for the flights aboard the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) Twin Otter aircraft, together with: a Picarro fast in-situ greenhouse gas (GHG) analyzer operated by the NASA Ames Research Center, ARC; a 5-hole turbulence probe; and an atmospheric measurement package operated by CIRPAS measuring aerosols, temperature, dew-point, and other atmospheric parameters. Three of the flights were accompanied by the Next Generation Airborne Visual InfraRed Imaging Spectrometer (AVIRIS-NG), operated by the Jet Propulsion Laboratory (JPL), California Institute of Technology, installed aboard a second Twin Otter aircraft. Large-scale, high-concentration CH4 plumes were detected by the MAMAP instrument over the fields and tracked over several kilometers. The spatial distribution of the MAMAP observed plumes was compared to high spatial resolution CH4 anomaly maps derived by AVIRIS-NG imaging spectroscopy data. Remote sensing data collected by MAMAP was used to infer CH4 emission rates and their distributions over the three fields. Aggregated emission estimates for the three fields were compared to aggregated emissions inferred by subsequent airborne in-situ validation measurements collected by the Picarro instrument. Comparison of remote sensing and in-situ flux estimates will be presented, demonstrating the ability of airborne remote sensing data to provide accurate emission estimates for concentrations above the

Analyzing source apportioned methane in northern California during Discover-AQ-CA using airborne measurements and model simulations

NASA Astrophysics Data System (ADS)

Johnson, Matthew S.; Yates, Emma L.; Iraci, Laura T.; Loewenstein, Max; Tadić, Jovan M.; Wecht, Kevin J.; Jeong, Seongeun; Fischer, Marc L.

2014-12-01

This study analyzes source apportioned methane (CH4) emissions and atmospheric mixing ratios in northern California during the Discover-AQ-CA field campaign using airborne measurement data and model simulations. Source apportioned CH4 emissions from the Emissions Database for Global Atmospheric Research (EDGAR) version 4.2 were applied in the 3-D chemical transport model GEOS-Chem and analyzed using airborne measurements taken as part of the Alpha Jet Atmospheric eXperiment over the San Francisco Bay Area (SFBA) and northern San Joaquin Valley (SJV). During the time period of the Discover-AQ-CA field campaign EDGAR inventory CH4 emissions were ∼5.30 Gg day-1 (Gg = 1.0 × 109 g) (equating to ∼1.90 × 103 Gg yr-1) for all of California. According to EDGAR, the SFBA and northern SJV region contributes ∼30% of total CH4 emissions from California. Source apportionment analysis during this study shows that CH4 mixing ratios over this area of northern California are largely influenced by global emissions from wetlands and local/global emissions from gas and oil production and distribution, waste treatment processes, and livestock management. Model simulations, using EDGAR emissions, suggest that the model under-estimates CH4 mixing ratios in northern California (average normalized mean bias (NMB) = -5.2% and linear regression slope = 0.20). The largest negative biases in the model were calculated on days when large amounts of CH4 were measured over local emission sources and atmospheric CH4 mixing ratios reached values >2.5 parts per million. Sensitivity emission studies conducted during this research suggest that local emissions of CH4 from livestock management processes are likely the primary source of the negative model bias. These results indicate that a variety, and larger quantity, of measurement data needs to be obtained and additional research is necessary to better quantify source apportioned CH4 emissions in California.

Analyzing Source Apportioned Methane in Northern California During DISCOVER-AQ-CA Using Airborne Measurements and Model Simulations

NASA Technical Reports Server (NTRS)

Johnson, Matthew S.

2014-01-01

This study analyzes source apportioned methane (CH4) emissions and atmospheric concentrations in northern California during the Discover-AQ-CA field campaign using airborne measurement data and model simulations. Source apportioned CH4 emissions from the Emissions Database for Global Atmospheric Research (EDGAR) version 4.2 were applied in the 3-D chemical transport model GEOS-Chem and analyzed using airborne measurements taken as part of the Alpha Jet Atmospheric eXperiment over the San Francisco Bay Area (SFBA) and northern San Joaquin Valley (SJV). During the time period of the Discover-AQ-CA field campaign EDGAR inventory CH4 emissions were 5.30 Gg/day (Gg 1.0 109 grams) (equating to 1.9 103 Gg/yr) for all of California. According to EDGAR, the SFBA and northern SJV region contributes 30 of total emissions from California. Source apportionment analysis during this study shows that CH4 concentrations over this area of northern California are largely influenced by global emissions from wetlands and local/global emissions from gas and oil production and distribution, waste treatment processes, and livestock management. Model simulations, using EDGAR emissions, suggest that the model under-estimates CH4 concentrations in northern California (average normalized mean bias (NMB) -5 and linear regression slope 0.25). The largest negative biases in the model were calculated on days when hot spots of local emission sources were measured and atmospheric CH4 concentrations reached values 3.0 parts per million (model NMB -10). Sensitivity emission studies conducted during this research suggest that local emissions of CH4 from livestock management processes are likely the primary source of the negative model bias. These results indicate that a variety, and larger quantity, of measurement data needs to be obtained and additional research is necessary to better quantify source apportioned CH4 emissions in California and further the understanding of the physical processes

Analyzing source apportioned methane in northern California during Discover-AQ-CA using airborne measurements and model simulations

DOE PAGES

Johnson, Matthew S.; Yates, Emma L.; Iraci, Laura T.; ...

2014-12-01

This study analyzes source apportioned methane (CH 4) emissions and atmospheric mixing ratios in northern California during the Discover-AQ-CA field campaign using airborne measurement data and model simulations. Source apportioned CH 4 emissions from the Emissions Database for Global Atmospheric Research (EDGAR) version 4.2 were applied in the 3-D chemical transport model GEOS-Chem and analyzed using airborne measurements taken as part of the Alpha Jet Atmospheric eXperiment over the San Francisco Bay Area (SFBA) and northern San Joaquin Valley (SJV). During the time period of the Discover-AQ-CA field campaign EDGAR inventory CH 4 emissions were ~5.30 Gg day –1 (Ggmore » = 1.0 × 10 9 g) (equating to ~1.90 × 10 3 Gg yr –1) for all of California. According to EDGAR, the SFBA and northern SJV region contributes ~30% of total CH 4 emissions from California. Source apportionment analysis during this study shows that CH 4 mixing ratios over this area of northern California are largely influenced by global emissions from wetlands and local/global emissions from gas and oil production and distribution, waste treatment processes, and livestock management. Model simulations, using EDGAR emissions, suggest that the model under-estimates CH 4 mixing ratios in northern California (average normalized mean bias (NMB) = –5.2% and linear regression slope = 0.20). The largest negative biases in the model were calculated on days when large amounts of CH 4 were measured over local emission sources and atmospheric CH 4 mixing ratios reached values >2.5 parts per million. Sensitivity emission studies conducted during this research suggest that local emissions of CH 4 from livestock management processes are likely the primary source of the negative model bias. These results indicate that a variety, and larger quantity, of measurement data needs to be obtained and additional research is necessary to better quantify source apportioned CH 4 emissions in California.« less

Simultaneous and Independent Measurement of Atmospheric Water Vapor and Carbon Dioxide using a Triple-Pulsed, 2-micron Airborne IPDA Lidar - A Feasibility Study

NASA Astrophysics Data System (ADS)

Singh, U. N.; Refaat, T. F.; Yu, J.; Petros, M.

2013-12-01

Water vapor (H2O) and carbon dioxide (CO2) are dominant greenhouse gases that are critical for Earth's radiation budget and global warming through the eco-system and the carbon cycle. NASA Langley Research Center (LaRC) has a strong heritage in atmospheric remote sensing of both gases using several instruments adopting various DIAL techniques. This communication presents a feasibility study for measuring both H2O and CO2 simultaneously and independently using a single instrument. This instrument utilizes the Integrated Path Differential Absorption (IPDA) lidar technique to measure the weighted-average column dry-air mixing ratios of CO2 (XCO2) and H2O (XH2O) independently and simultaneously from an airborne platform. The key component of this instrument is a tunable triple-pulse 2-micron laser. The three laser pulses are transmitted sequentially within a short time interval of 200 microsec. The wavelength of each of the laser pulses can be tuned separately. The IPDA receiver design is based on low-risk, commercially available components, including 300-micron diameter InGaAs 2-micron pin detector, a low-noise, high speed trans-impedance amplifier (TIA) and 12-bit 400 MHz digitizer.

Airborne volcanic plume measurements using a FTIR spectrometer, Kilauea volcano, Hawaii

USGS Publications Warehouse

McGee, K.A.; Gerlach, T.M.

1998-01-01

A prototype closed-path Fourier transform infrared spectrometer system (FTIK), operating from battery power and with a Stirling engine microcooler for detector cooling, was successfully used for airborne measurements of sulfur dioxide at Kilauea volcano. Airborne profiles of the volcanic plume emanating from the erupting Pu'u 'O'o vent on the East Rift of Kilauea revealed levels of nearly 3 ppm SO2 in the core of the plume. An emission rate of 2,160 metric tons per day of sulfur dioxide was calculated from the FTIR data, which agrees closely with simultaneous measurements by a correlation spectrometer (COSPEC). The rapid spatial sampling possible from an airborne platform distinguishes the methodology described here from previous FTIR measurements.

Assessment of Airborne Instrument Uncertainty via Measurement Comparisons Conducted During the DC3 and SEAC4RS Field Campaigns

NASA Astrophysics Data System (ADS)

Silverman, M. L.; Chen, G.; Shook, M.

2016-12-01

Airborne field campaigns have long understood the importance of well-defined measurement uncertainties and their impact on scientific research. Measurement comparisons are an effective way to assess the uncertainty of different techniques as well as gain insight into instrument performance. As part of the NASA DC3 (Deep Convective Clouds and Chemistry) airborne field campaign, there were several wing-tip-to-wing-tip formation flight segments designed for measurement comparison of the instruments onboard the NASA DC-8 and NSF/NCAR Gulfstream-V aircraft. This provides the opportunity to evaluate the consistency between multiple measurements of the same species/parameters on different platforms and based on different measurement techniques. The DC-8 aircraft was also instrumented with duplicate measurements of the same species, allowing for intraplatform comparisons. The NASA DC-8 was also used during the NASA SEAC4RS (Studies of Emission and Atmospheric Composition, Clouds, and Climate Coupling by Regional Surveys) airborne field campaign. While no wing-tip to wing-tip flights were flown, several instruments measuring the same species were aboard the DC-8 providing intraplatform comparisons. Time series and correlations are produced to show the relative agreement between the measurements both on a daily basis and over the course of the five inter-comparison days. We have also used a data-driven approach to analyze the instrument precisions as an important part of measurement uncertainty assessment. By conducting these analyses we provide insight to users on the quality of the measurements.

Evidence for CO in Jupiter's atmosphere from airborne spectroscopic observations at 5 microns

NASA Technical Reports Server (NTRS)

Larson, H. P.; Fink, U.; Treffers, R. R.

1978-01-01

High-altitude (12.4 km) spectra of Jupiter recorded at the Kuiper Airborne Observatory are analyzed for the presence of CO absorption lines. A line-by-line comparison of Jupiter's spectrum with that of carbon monoxide is presented, as well as a correlation analysis that includes the influence of other gases present in Jupiter's atmosphere (CH4, NH3, H2O, PH3, and GeH4). The resulting evidence points strongly to the presence of carbon monoxide in Jupiter's atmosphere, thus strengthening Beer's evidence for it. Possible explanations for the existence and observability of Jovian CO, including convection from hotter, deeper layers or decomposition of organic molecules, are explored. A recent suggestion that the Jovian CO is restricted to stratospheric levels is not supported by the observations.

Airborne tunable diode laser spectrometer for trace-gas measurement in the lower stratosphere

NASA Technical Reports Server (NTRS)

Podolske, James; Loewenstein, Max

1993-01-01

This paper describes the airborne tunable laser absorption spectrometer, a tunable diode laser instrument designed for in situ trace-gas measurement in the lower stratosphere from an ER-2 high-altitude research aircraft. Laser-wavelength modulation and second-harmonic detection are employed to achieve the required constituent detection sensitivity. The airborne tunable laser absorption spectrometer was used in two polar ozone campaigns, the Airborne Antarctic Ozone Experiment and the Airborne Arctic Stratospheric Expedition, and measured nitrous oxide with a response time of 1 s and an accuracy not greater than 10 percent.

Airborne and spaceborne lasers for terrestrial geophysical sensing; Proceedings of the Meeting, Los Angeles, CA, Jan. 14, 15, 1988

NASA Technical Reports Server (NTRS)

Allario, Frank (Editor)

1988-01-01

The present conference on airborne and spaceborne remote sensing laser applications discusses topics in atmospheric and geophysical sciences-related sensors, lidar and DIAL component and subsystem technologies, and coherent laser experiments and semiconductor laser technologies. Attention is given to airborne lidar measurement of aerosols, a ground-based injection-locked pulsed TEA laser for wind measurements, chemical/biological agent standoff detection methods, lidars for wind shear erosion, laser tuning to selected gas absorption lines in the atmosphere, the NASA lidar-in-space technology experiment, and the Laser Atmospheric Wind Sounder.

An Overview of the Challenges with and Proposed Solutions for the Ingest and Distribution Processes For Airborne Data Management

NASA Astrophysics Data System (ADS)

Northup, E. A.; Beach, A. L., III; Early, A. B.; Kusterer, J.; Quam, B.; Wang, D.; Chen, G.

2015-12-01

The current data management practices for NASA airborne field projects have successfully served science team data needs over the past 30 years to achieve project science objectives, however, users have discovered a number of issues in terms of data reporting and format. The ICARTT format, a NASA standard since 2010, is currently the most popular among the airborne measurement community. Although easy for humans to use, the format standard is not sufficiently rigorous to be machine-readable, and there lacks a standard variable naming convention among the many airborne measurement variables. This makes data use and management tedious and resource intensive, and also create problems in Distributed Active Archive Center (DAAC) data ingest procedures and distribution. Further, most DAACs use metadata models that concentrate on satellite data observations, making them less prepared to deal with airborne data. There also exists a substantial amount of airborne data distributed by websites designed for science team use that are less friendly to users unfamiliar with operations of airborne field studies. A number of efforts are underway to help overcome the issues with airborne data discovery and distribution. The ICARTT Refresh Earth Science Data Systems Working Group (ESDSWG) was established to enable a platform for atmospheric science data providers, users, and data managers to collaborate on developing new criteria for the file format in an effort to enhance airborne data usability. In addition, the NASA Langley Research Center Atmospheric Science Data Center (ASDC) has developed the Toolsets for Airborne Data (TAD) to provide web-based tools and centralized access to airborne in situ measurements of atmospheric composition. This presentation will discuss the aforementioned challenges and attempted solutions in an effort to demonstrate how airborne data management can be improved to streamline data ingest and discoverability to a broader user community.

Managing Large Datasets for Atmospheric Research

NASA Technical Reports Server (NTRS)

Chen, Gao

2015-01-01

Since the mid-1980s, airborne and ground measurements have been widely used to provide comprehensive characterization of atmospheric composition and processes. Field campaigns have generated a wealth of insitu data and have grown considerably over the years in terms of both the number of measured parameters and the data volume. This can largely be attributed to the rapid advances in instrument development and computing power. The users of field data may face a number of challenges spanning data access, understanding, and proper use in scientific analysis. This tutorial is designed to provide an introduction to using data sets, with a focus on airborne measurements, for atmospheric research. The first part of the tutorial provides an overview of airborne measurements and data discovery. This will be followed by a discussion on the understanding of airborne data files. An actual data file will be used to illustrate how data are reported, including the use of data flags to indicate missing data and limits of detection. Retrieving information from the file header will be discussed, which is essential to properly interpreting the data. Field measurements are typically reported as a function of sampling time, but different instruments often have different sampling intervals. To create a combined data set, the data merge process (interpolation of all data to a common time base) will be discussed in terms of the algorithm, data merge products available from airborne studies, and their application in research. Statistical treatment of missing data and data flagged for limit of detection will also be covered in this section. These basic data processing techniques are applicable to both airborne and ground-based observational data sets. Finally, the recently developed Toolsets for Airborne Data (TAD) will be introduced. TAD (tad.larc.nasa.gov) is an airborne data portal offering tools to create user defined merged data products with the capability to provide descriptive

Measuring Radiant Emissions from Entire Prescribed Fires with Ground, Airborne and Satellite Sensors RxCADRE 2012

NASA Technical Reports Server (NTRS)

Dickinson, Matthew B.; Hudak, Andrew T.; Zajkowski, Thomas; Loudermilk, E. Louise; Schroeder, Wilfrid; Ellison, Luke; Kremens, Robert L.; Holley, William; Martinez, Otto; Paxton, Alexander;

Airborne UV DIAL Measurements of Ozone and Aerosols

NASA Technical Reports Server (NTRS)

Grant, William B.; Browell, Edward V.

2000-01-01

The NASA Langley Research Center's airborne UV Differential Absorption Lidar (DIAL) system measures vertical profiles of ozone and aerosols above and below the aircraft along its flight track. This system has been used in over 20 airborne field missions designed to study the troposphere and stratosphere since 1980. Four of these missions involved tropospheric measurement programs in the Pacific Ocean with two in the western North Pacific and two in the South Pacific. The UV DIAL system has been used in these missions to study such things as pollution outflow, long-range transport, and stratospheric intrusions; categorize the air masses encountered; and to guide the aircraft to altitudes where interesting features can be studied using the in situ instruments. This paper will highlight the findings with the UV DIAL system in the Pacific Ocean field programs and introduce the mission planned for the western North Pacific for February-April 2001. This will be an excellent opportunity for collaboration between the NASA airborne mission and those with ground-based War systems in Asia Pacific Rim countries to make a more complete determination of the transport of air from Asia to the western Pacific.

Upgrade of the NASA 4STAR (Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research) to its Full Science Capability of Sun-Sky-Cloud-Trace Gas Spectrometry in Airborne Science Deployments

NASA Technical Reports Server (NTRS)

Johnson, Roy R.; Russell, P.; Dunagan, S.; Redemann, J.; Shinozuka, Y.; Segal-Rosenheimer, M.; LeBlanc, S.; Flynn, C.; Schmid, B.; Livingston, J.

2014-01-01

The objectives of this task in the AITT (Airborne Instrument Technology Transition) Program are to (1) upgrade the NASA 4STAR (Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research) instrument to its full science capability of measuring (a) direct-beam sun transmission to derive aerosol optical depth spectra, (b) sky radiance vs scattering angle to retrieve aerosol absorption and type (via complex refractive index spectra, shape, and mode-resolved size distribution), (c) zenith radiance for cloud properties, and (d) hyperspectral signals for trace gas retrievals, and (2) demonstrate its suitability for deployment in challenging NASA airborne multiinstrument campaigns. 4STAR combines airborne sun tracking, sky scanning, and zenith pointing with diffraction spectroscopy to improve knowledge of atmospheric constituents and their links to air pollution, radiant energy budgets (hence climate), and remote measurements of Earth's surfaces. Direct beam hyperspectral measurement of optical depth improves retrievals of gas constituents and determination of aerosol properties. Sky scanning enhances retrievals of aerosol type and size distribution. 4STAR measurements are intended to tighten the closure between satellite and ground-based measurements. 4STAR incorporates a modular sun-tracking/sky-scanning optical head with fiber optic signal transmission to rack mounted spectrometers, permitting miniaturization of the external optical head, and future detector evolution. 4STAR test flights, as well as science flights in the 2012-13 TCAP (Two-Column Aerosol Project) and 2013 SEAC4RS (Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys) have demonstrated that the following are essential for 4STAR to achieve its full science potential: (1) Calibration stability for both direct-beam irradiance and sky radiance, (2) Improved light collection and usage, and (3) Improved flight operability and reliability. A particular challenge

Fourth Airborne Geoscience Workshop

NASA Technical Reports Server (NTRS)

1991-01-01

The focus of the workshop was on how the airborne community can assist in achieving the goals of the Global Change Research Program. The many activities that employ airborne platforms and sensors were discussed: platforms and instrument development; airborne oceanography; lidar research; SAR measurements; Doppler radar; laser measurements; cloud physics; airborne experiments; airborne microwave measurements; and airborne data collection.

Comparison of Carbon Dioxide Airborne Measurement over Land and Ocean using 2-μm Double-Pulse Integrated Path Differential Absorption Lidar

NASA Astrophysics Data System (ADS)

Refaat, T. F.; Singh, U. N.; Petros, M.; Yu, J.; Remus, R.; Ismail, S.

2017-12-01

An airborne Integrated Path Differential Absorption (IPDA) lidar has been developed and validated at NASA Langley Research Center for atmospheric carbon dioxide column measurements. The instrument consists of a tunable, high-energy 2-μm double pulse laser transmitter and 0.4 m telescope receiver coupled to an InGaAs pin detection system. The instrument was validated for carbon dioxide (CO2) measurements from ground and airborne platforms, using a movable lidar trailer and the NASA B-200 aircraft. Airborne validation was conducted over the ocean by comparing the IPDA CO2 optical depth measurement to optical depth model derived using NOAA airborne CO2 air-sampling. Another airborne validation was conducted over land vegetation by comparing the IPDA measurement to a model derived using on-board in-situ measurements using an absolute, non-dispersive infrared gas analyzer (LiCor 840A). IPDA range measurements were also compared to rangefinder and Global Positioning System (GPS) records during ground and airborne validation, respectively. Range measurements from the ground indicated a 0.93 m IPDA range measurement uncertainty, which is limited by the transmitted laser pulse and detection system properties. This uncertainty increased to 2.80 and 7.40 m over ocean and land, due to fluctuations in ocean surface and ground elevations, respectively. IPDA CO2 differential optical depth measurements agree with both models. Consistent CO2 optical depth biases were well correlated with the digitizer full scale input range settings. CO2 optical depth measurements over ocean from 3.1 and 6.1 km altitudes indicated 0.95% and 0.83% uncertainty, respectively, using 10 second (100 shots) averaging. Using the same averaging 0.40% uncertainty was observed over land, from 3.4 km altitude, due to higher surface reflectivity, which increases the return signal power and enhances the signal-to-noise ratio. However, less uncertainty is observed at higher altitudes due to reduced signal shot

Sensor Performance Requirements for the Retrieval of Atmospheric Aerosols by Airborne Optical Remote Sensing.

PubMed

Seidel, Felix; Schläpfer, Daniel; Nieke, Jens; Itten, Klaus I

2008-03-18

This study explores performance requirements for the retrieval of the atmospheric aerosol optical depth (AOD) by airborne optical remote sensing instruments. Independent of any retrieval techniques, the calculated AOD retrieval requirements are compared with the expected performance parameters of the upcoming hyperspectral sensor APEX at the reference wavelength of 550nm. The AOD accuracy requirements are defined to be capable of resolving transmittance differences of 0.01 to 0.04 according to the demands of atmospheric corrections for remote sensing applications. For the purposes of this analysis, the signal at the sensor level is simulated by radiation transfer equations. The resulting radiances are translated into the AOD retrieval sensitivity (Δτ λ aer ) and compared to the available measuring sensitivity of the sensor (NE ΔL λ sensor ). This is done for multiple signal-to-noise ratios (SNR) and surface reflectance values. It is shown that an SNR of 100 is adequate for AOD retrieval at 550nm under typical remote sensing conditions and a surface reflectance of 10% or less. Such dark surfaces require the lowest SNR values and therefore offer the best sensitivity for measuring AOD. Brighter surfaces with up to 30% reflectance require an SNR of around 300. It is shown that AOD retrieval for targets above 50% surface reflectance is more problematic with the current sensor performance as it may require an SNR larger than 1000. In general, feasibility is proven for the analyzed cases under simulated conditions.

Sensor Performance Requirements for the Retrieval of Atmospheric Aerosols by Airborne Optical Remote Sensing

PubMed Central

Seidel, Felix; Schläpfer, Daniel; Nieke, Jens; Itten, Klaus I.

2008-01-01

This study explores performance requirements for the retrieval of the atmospheric aerosol optical depth (AOD) by airborne optical remote sensing instruments. Independent of any retrieval techniques, the calculated AOD retrieval requirements are compared with the expected performance parameters of the upcoming hyperspectral sensor APEX at the reference wavelength of 550nm. The AOD accuracy requirements are defined to be capable of resolving transmittance differences of 0.01 to 0.04 according to the demands of atmospheric corrections for remote sensing applications. For the purposes of this analysis, the signal at the sensor level is simulated by radiation transfer equations. The resulting radiances are translated into the AOD retrieval sensitivity (Δτλaer) and compared to the available measuring sensitivity of the sensor (NEΔLλsensor). This is done for multiple signal-to-noise ratios (SNR) and surface reflectance values. It is shown that an SNR of 100 is adequate for AOD retrieval at 550nm under typical remote sensing conditions and a surface reflectance of 10% or less. Such dark surfaces require the lowest SNR values and therefore offer the best sensitivity for measuring AOD. Brighter surfaces with up to 30% reflectance require an SNR of around 300. It is shown that AOD retrieval for targets above 50% surface reflectance is more problematic with the current sensor performance as it may require an SNR larger than 1000. In general, feasibility is proven for the analyzed cases under simulated conditions. PMID:27879801

Development of a Coherent Differential Absorption Lidar for Range Resolved Atmospheric CO2 Measurements

NASA Technical Reports Server (NTRS)

Yu, Jirong; Petros, Mulgueta; Chen, Songsheng; Bai, Yingxin; Petzar, Paul J.; Trieu, Bo. C.; Koch, Grady J.; Beyon, Jeffery J.; Singh, Upendra N.

2010-01-01

A pulsed, 2-m coherent Differential Absorption Lidar (DIAL) / Integrated Path Differential Absorption (IPDA) transceiver, developed under the Laser Risk Reduction Program (LRRP) at NASA, is integrated into a fully functional lidar instrument. This instrument will measure atmospheric CO2 profiles (by DIAL) initially from a ground platform, and then be prepared for aircraft installation to measure the atmospheric CO2 column densities in the atmospheric boundary layer (ABL) and lower troposphere. The airborne prototype CO2 lidar can measure atmospheric CO2 column density in a range bin of 1km with better than 1.5% precision at horizontal resolution of less than 50km. It can provide the image of the pooling of CO2 in lowlying areas and performs nighttime mass balance measurements at landscape scale. This sensor is unique in its capability to study the vertical ABL-free troposphere exchange of CO2 directly. It will allow the investigators to pursue subsequent in science-driven deployments, and provides a unique tool for Active Sensing of CO2 Emissions over Night, Days, and Seasons (ASCENDS) validation that was strongly advocated in the recent ASCENDS Workshop.

Validating Above-cloud Aerosol Optical Depth Retrieved from MODIS using NASA Ames Airborne Sun-Tracking Photometric and Spectrometric (AATS and 4STAR) Measurements

NASA Astrophysics Data System (ADS)

Jethva, H. T.; Torres, O.; Remer, L. A.; Redemann, J.; Dunagan, S. E.; Livingston, J. M.; Shinozuka, Y.; Kacenelenbogen, M. S.; Segal-Rosenhaimer, M.

2014-12-01

Absorbing aerosols produced from biomass burning and dust outbreaks are often found to overlay the lower level cloud decks as evident in the satellite images. In contrast to the cloud-free atmosphere, in which aerosols generally tend to cool the atmosphere, the presence of absorbing aerosols above cloud poses greater potential of exerting positive radiative effects (warming) whose magnitude directly depends on the aerosol loading above cloud, optical properties of clouds and aerosols, and cloud fraction. In recent years, development of algorithms that exploit satellite-based passive measurements of ultraviolet (UV), visible, and polarized light as well as lidar-based active measurements constitute a major breakthrough in the field of remote sensing of aerosols. While the unprecedented quantitative information on aerosol loading above cloud is now available from NASA's A-train sensors, a greater question remains ahead: How to validate the satellite retrievals of above-cloud aerosols (ACA)? Direct measurements of ACA such as carried out by the NASA Ames Airborne Tracking Sunphotometer (AATS) and Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) can be of immense help in validating ACA retrievals. In this study, we validate the ACA optical depth retrieved using the 'color ratio' (CR) method applied to the MODIS cloudy-sky reflectance by using the airborne AATS and 4STAR measurements. A thorough search of the historic AATS-4STAR database collected during different field campaigns revealed five events where biomass burning, dust, and wildfire-emitted aerosols were found to overlay lower level cloud decks observed during SAFARI-2000, ACE-ASIA 2001, and SEAC4RS-2013, respectively. The co-located satellite-airborne measurements revealed a good agreement (root-mean-square-error<0.1 for Aerosol Optical Depth (AOD) at 500 nm) with most matchups falling within the estimated uncertainties in the MODIS retrievals (-10% to +50%). An extensive validation of

Challenges in the Management and Stewardship of Airborne Observational Data at the National Center for Atmospheric Research (NCAR) Earth Observing Laboratory (EOL)

NASA Astrophysics Data System (ADS)

Aquino, J.; Daniels, M. D.

2015-12-01

The National Science Foundation (NSF) provides the National Center for Atmospheric Research (NCAR) Earth Observing Laboratory (EOL) funding for the operation, maintenance and upgrade of two research aircraft: the NSF/NCAR High-performance Instrumented Airborne Platform for Environmental Research (HIAPER) Gulfstream V and the NSF/NCAR Hercules C-130. A suite of in-situ and remote sensing airborne instruments housed at the EOL Research Aviation Facility (RAF) provide a basic set of measurements that are typically deployed on most airborne field campaigns. In addition, instruments to address more specific research requirements are provided by collaborating participants from universities, industry, NASA, NOAA or other agencies (referred to as Principal Investigator, or PI, instruments). At the 2014 AGU Fall Meeting, a poster (IN13B-3639) was presented outlining the components of Airborne Data Management included field phase data collection, formats, data archival and documentation, version control, storage practices, stewardship and obsolete data formats, and public data access. This talk will cover lessons learned, challenges associated with the above components, and current developments to address these challenges, including: tracking data workflows for aircraft instrumentation to facilitate identification, and correction, of gaps in these workflows; implementation of dataset versioning guidelines; and assignment of Digital Object Identifiers (DOIs) to data and instrumentation to facilitate tracking data and facility use in publications.

Aerosol Properties Derived from Airborne Sky Radiance and Direct Beam Measurements in Recent NASA and DoE Field Campaigns

NASA Technical Reports Server (NTRS)

Redemann, J.; Flynn, C. J.; Shinozuka, Y.; Russell, P. B.; Kacenelenbogen, M.; Segal-Rosenheimer, M.; Livingston, J. M.; Schmid, B.; Dunagan, S. E.; Johnson, R. R.;

NASA's Student Airborne Research Program (SARP) 2009-2017

NASA Astrophysics Data System (ADS)

Schaller, E. L.

2017-12-01

The NASA Student Airborne Research Program (SARP) is a unique summer internship program for rising senior undergraduates majoring in any of the STEM disciplines. SARP participants acquire hands-on research experience in all aspects of a NASA airborne campaign, including flying onboard NASA research aircraft while studying Earth system processes. Approximately thirty-two students are competitively selected each summer from colleges and universities across the United States. Students work in four interdisciplinary teams to study surface, atmospheric, and oceanographic processes. Participants assist in the operation of instruments onboard NASA aircraft where they sample and measure atmospheric gases and image land and water surfaces in multiple spectral bands. Along with airborne data collection, students participate in taking measurements at field sites. Mission faculty and research mentors help to guide participants through instrument operation, sample analysis, and data reduction. Over the eight-week program, each student develops an individual research project from the data collected and delivers a conference-style final presentation on their results. Each year, several students present the results of their SARP research projects in scientific sessions at this meeting. We discuss the results and effectiveness of the program over the past nine summers and plans for the future.

Airborne and Ground-Based Measurements Using a High-Performance Raman Lidar. Part 2; Ground Based

NASA Technical Reports Server (NTRS)

Whiteman, David N.; Cadirola, Martin; Venable, Demetrius; Connell, Rasheen; Rush, Kurt; Leblanc, Thierry; McDermid, Stuart

2009-01-01

The same RASL hardware as described in part I was installed in a ground-based mobile trailer and used in a water vapor lidar intercomparison campaign, hosted at Table Mountain, CA, under the auspices of the Network for the Detection of Atmospheric Composition Change (NDACC). The converted RASL hardware demonstrated high sensitivity to lower stratospheric water vapor indicating that profiling water vapor at those altitudes with sufficient accuracy to monitor climate change is possible. The measurements from Table Mountain also were used to explain the reason, and correct , for sub-optimal airborne aerosol extinction performance during the flight campaign.

Sources and sinks of ozone in savanna and forest areas during EXPRESSO: Airborne turbulent flux measurements

NASA Astrophysics Data System (ADS)

Cros, B.; Delon, C.; Affre, C.; Marion, T.; Druilhet, A.; Perros, P. E.; Lopez, A.

2000-12-01

An airborne study of ozone concentrations and fluxes in the lower layers of the atmosphere was conducted over the Central African Republic (CAR) and northern Congo in November/December 1996, within the framework of the Experiment of Regional Sources and Sinks of Oxidants (EXPRESSO). The first 4 km of the atmosphere above savanna, rain forest, and the transitional area between them, were investigated with the French research aircraft Avion de Recherche Atmosphérique et de Télédétection (ARAT). Turbulent fluxes and deposition velocities of ozone were determined using the Eddy Correlation (EC) method. A specific methodology was developed to obtain accurate airborne turbulent flux measurements. This methodology is linked to the turbulence stationarity. The average values of ozone fluxes and ozone deposition velocities in the Atmospheric Boundary Layer (ABL) increase appreciably from savanna to forest. Near the ground, the ozone fluxes range between -0.115 +/-0.073 ppbv m/s above savanna and -0.350 +/-0.115 ppbv m/s above forest; for the deposition, the ranges are 0.0042 +/-0.0018 m/s and 0.015 +/-0.004 m/s. A simple empirical relationship between deposition velocity and Leaf Area Index (LAI) is proposed, giving an estimation of the deposition velocity for a whole latitudinal band. Vertical inputs of ozone to the ABL are estimated according to entrainment fluxes. The role of advection is neglected for horizontal transport of ozone in the ABL. The photochemical ozone production is deduced from the photo-stationary state deviation, and compared to the net ozone increase in the ABL during the flights performed above the forest. A tentative ozone budget based on the aircraft measurements is proposed in the ABL of the rain forest. Around noon, the photochemical production dominates with a net production of about 10 ppbv/h.

Sun and aureole spectrometer for airborne measurements to derive aerosol optical properties.

PubMed

Asseng, Hagen; Ruhtz, Thomas; Fischer, Jürgen

2004-04-01

We have designed an airborne spectrometer system for the simultaneous measurement of the direct Sun irradiance and aureole radiance. The instrument is based on diffraction grating spectrometers with linear image sensors. It is robust, lightweight, compact, and reliable, characteristics that are important for airborne applications. The multispectral radiation measurements are used to derive optical properties of tropospheric aerosols. We extract the altitude dependence of the aerosol volume scattering function and of the aerosol optical depth by using flight patterns with descents and ascents ranging from the surface level to the top of the boundary layer. The extinction coefficient and the product of single scattering albedo and phase function of separate layers can be derived from the airborne measurements.

Spatial Variations in CO2 Mixing Ratios Over a Heterogenous Landscape - Linking Airborne Measurements With Remote Sensing Derived Biophysical Parameters

NASA Astrophysics Data System (ADS)

Choi, Y.; Vadrevu, K. P.; Vay, S. A.; Woo, J.

2006-12-01

North American terrestrial ecosystems are major sources and sinks of carbon. Precise measurement of atmospheric CO2 concentrations plays an important role in the development and testing of carbon cycle models quantifying the influence of terrestrial CO2 exchange on the North American carbon budget. During the summer 2004 Intercontinental Chemical Transport Experiment North America (INTEX-NA) campaign, regional scale in-situ measurements of atmospheric CO2 were made from the NASA DC-8 affording the opportunity to explore how land surface heterogeneity relates to the airborne observations utilizing remote-sensing data products and GIS-based methods. These 1 Hz data reveal the seasonal biospheric uptake of CO2 over portions of the U.S. continent, especially east of 90°W below 2 km, compared to higher mixing ratios over water as well as within the upper troposphere where well-mixed, aged air masses were sampled. In this study, we use several remote sensing derived biophysical parameters from the LANDSAT, NOAA AVHRR, and MODIS sensors to specify spatiotemporal patterns of land use cover and vegetation characteristics for linking the airborne measurements of CO2 data with terrestrial sources of carbon. Also, CO2 flux footprint outputs from a 3-D Lagrangian atmospheric model have been integrated with satellite remote sensing data to infer CO2 variations across heterogeneous landscapes. In examining the landscape mosaic utilizing these available tools, preliminary results suggest that the lowest CO2 mixing ratios observed during INTEX-NA were over agricultural fields in Illinois dominated by corn then secondarily soybean crops. Low CO2 concentrations are attributable to sampling during the peak growing season over such C4 plants as corn having a higher photosynthetic rate via the C4-dicarboxylic acid pathway of carbon fixation compared to C3 plants such as soybeans. In addition to LANDSAT derived land cover data, results from comparisons of the airborne CO2 observations

Airborne instruments to measure atmospheric aerosol particles, clouds and radiation: A cook's tour of mature and emerging technology

NASA Astrophysics Data System (ADS)

Baumgardner, D.; Brenguier, J. L.; Bucholtz, A.; Coe, H.; DeMott, P.; Garrett, T. J.; Gayet, J. F.; Hermann, M.; Heymsfield, A.; Korolev, A.; Krämer, M.; Petzold, A.; Strapp, W.; Pilewskie, P.; Taylor, J.; Twohy, C.; Wendisch, M.; Bachalo, W.; Chuang, P.

2011-10-01

An overview is presented of airborne systems for in situ measurements of aerosol particles, clouds and radiation that are currently in use on research aircraft around the world. Description of the technology is at a level sufficient for introducing the basic principles of operation and an extensive list of references for further reading is given. A number of newer instruments that implement emerging technology are described and the review concludes with a description of some of the most important measurement challenges that remain. This overview is a synthesis of material from a reference book that is currently in preparation and that will be published in 2012 by Wiley.

A Compact Airborne System for SO2 and DMS Measurements for Use on Future GTE Missions Aboard the P-3 or DC-8

NASA Technical Reports Server (NTRS)

Saltzman, Eric S.; DeBruyn, Warren J.

2000-01-01

This project involved the design and construction of a new instrument for airborne measurement of DMS and SO2. The instrument is intended for use on field missions to study the global atmospheric sulfur cycle. The ultimate scientific goal is to provide insight into the mechanisms of atmospheric transport and transformations impacting both natural and anthropogenic sulfur emissions. This report summarizes the progress made to date and the goals for future work on the project. The PI's for this project have recently relocated from the University of Miami to the University of California, Irvine, and a request has been made to transfer remaining funds to UCI. All equipment associated with this project has been transferred to UCI. The instrument design goal was to develop an instrument roughly one quarter the size and weight of currently available airborne instrumentation used for DMS and S02 measurements. Another goal was full automation, to allow unattended operation for the duration of a P-3 or DC-8 flight. The original performance design specifications for the instrument are given.

The marine atmospheric boundary layer under strong wind conditions: Organized turbulence structure and flux estimates by airborne measurements

NASA Astrophysics Data System (ADS)

Brilouet, Pierre-Etienne; Durand, Pierre; Canut, Guylaine

2017-02-01

During winter, cold air outbreaks take place in the northwestern Mediterranean sea. They are characterized by local strong winds (Mistral and Tramontane) which transport cold and dry continental air across a warmer sea. In such conditions, high values of surface sensible and latent heat flux are observed, which favor deep oceanic convection. The HyMeX/ASICS-MED field campaign was devoted to the study of these processes. Airborne measurements, gathered in the Gulf of Lion during the winter of 2013, allowed for the exploration of the mean and turbulent structure of the marine atmospheric boundary layer (MABL). A spectral analysis based on an analytical model was conducted on 181 straight and level runs. Profiles of characteristic length scales and sharpness parameter of the vertical wind spectrum revealed larger eddies along the mean wind direction associated with an organization of the turbulence field into longitudinal rolls. These were highlighted by boundary layer cloud bands on high-resolution satellite images. A one-dimensional description of the vertical exchanges is then a tricky issue. Since the knowledge of the flux profile throughout the entire MABL is essential for the estimation of air-sea exchanges, a correction of eddy covariance turbulent fluxes was developed taking into account the systematic and random errors due to sampling and data processing. This allowed the improvement of surface fluxes estimates, computed from the extrapolation of the stacked levels. A comparison between those surface fluxes and bulk fluxes computed at a moored buoy revealed considerable differences, mainly regarding the latent heat flux under strong wind conditions.

Solid-State 2-Micron Laser Transmitter Advancement for Wind and Carbon Dioxide Measurements From Ground, Airborne, and Space-Based Lidar Systems

NASA Technical Reports Server (NTRS)

Singh, Upendra N.; Kavaya, Michael J.; Koch, Grady; Yu, Jirong; Ismail, Syed

2008-01-01

NASA Langley Research Center has been developing 2-micron lidar technologies over a decade for wind measurements, utilizing coherent Doppler wind lidar technique and carbon dioxide measurements, utilizing Differential Absorption Lidar (DIAL) technique. Significant advancements have been made towards developing state-of-the-art technologies towards laser transmitters, detectors, and receiver systems. These efforts have led to the development of solid-state lasers with high pulse energy, tunablility, wavelength-stability, and double-pulsed operation. This paper will present a review of these technological developments along with examples of high resolution wind and high precision CO2 DIAL measurements in the atmosphere. Plans for the development of compact high power lasers for applications in airborne and future space platforms for wind and regional to global scale measurement of atmospheric CO2 will also be discussed.

Low level measurements of atmospheric DMS, H2S, and SO2 for GTE/CITE-3

NASA Technical Reports Server (NTRS)

Saltzman, Eric; Cooper, David

1991-01-01

This project involved the measurement of atmospheric dimethylsulfide (DMS) and hydrogen sulfide (H2S) as part of the GTE/CITE-3 instrument intercomparison program. The two instruments were adapted for use on the NASA Electra aircraft and participated in all phases of the mission. This included ground-based measurements of NIST-provided standard gases and a series of airborne missions over the Western Atlantic Ocean. Analytical techniques used are described and the results are summarized.

Airborne Spectral Measurements of Surface-Atmosphere Anisotropy for Skukuza and Mongu Sites

NASA Technical Reports Server (NTRS)

Gatebe, C. K.; King, Michael D.; Arnold, G. T.; Li, J. Y.

2001-01-01

The Cloud Absorption Radiometer (CAR) was flown aboard the University of Washington Convair CV-580 research aircraft and took measurements on 23 flights between August 15 and September 16. On 12 of those flights, BRF (bidirectional reflection function) measurements were obtained over different natural surfaces and ecosystems in southern Africa. The BRF measurements were done to characterize surface anisotropy in support of SAFARI 2000 science objectives principally to validate products from NASA's EOS (Earth Observing System) satellites, and to parameterize and validate BRF models. In this paper we present results of BRFs taken over two EOS validation sites: Skukuza tower, South Africa (25.0 S, 31.5 E) and Mongu tower, Zambia (15.4 S, 23.3 E). The CAR is capable of measuring scattered light in fourteen spectral bands. The scan mirror, rotating at 100 rpm, directs the light into a Dall-Kirkham telescope where the beam is split into nine paths. Eight light beams pass through beam splitters, dichroics, and lenses to individual detectors (0.34-1.27 microns), and finally are registered by eight data channels. They are sampled simultaneously and continuously. The ninth beam passes through a spinning filter wheel to an InSb detector cooled by a Stirling cycle cooler. Signals registered by the ninth data channel are selected from among six spectral channels (1.55-2.30 microns). The filter wheel can either cycle through all six spectral bands at a prescribed interval (usually changing filter every fifth scan line), or lock onto any one of the six spectral bands and sample it continuously. To measure the BRF of the surface-atmosphere system, the University of Washington CV-580 had to bank at a comfortable roll angle of approximately 20 degrees and fly in a circle about 3 km in diameter above the surface for roughly two minutes. Replicated observations (multiple circular orbits) were acquired over selected surfaces so that average BRF smooth out small-scale surface and

Tropospheric Emission Spectrometer and Airborne Emission Spectrometer

NASA Technical Reports Server (NTRS)

Glavich, T.; Beer, R.

1996-01-01

The Tropospheric Emission Spectrometer (TES) is an instrument being developed for the NASA Earth Observing System Chemistry Platform. TES will measure the distribution of ozone and its precursors in the lower atmosphere. The Airborne Emission Spectrometer (AES) is an aircraft precursor to TES. Applicable descriptions are given of instrument design, technology challenges, implementation and operations for both.

Aerosol, Cloud and Trace Gas Observations Derived from Airborne Hyperspectral Radiance and Direct Beam Measurements in Recent Field Campaigns

NASA Technical Reports Server (NTRS)

Redemann, J.; Flynn, C. J.; Shinozuka, Y.; Kacenelenbogen, M.; Segal-Rosenheimer, M.; LeBlanc, S.; Russell, P. B.; Livingston, J. M.; Schmid, B.; Dunagan, S. E.;

Challenges and Opportunities of Airborne Metagenomics

PubMed Central

Behzad, Hayedeh; Gojobori, Takashi; Mineta, Katsuhiko

2015-01-01

Recent metagenomic studies of environments, such as marine and soil, have significantly enhanced our understanding of the diverse microbial communities living in these habitats and their essential roles in sustaining vast ecosystems. The increase in the number of publications related to soil and marine metagenomics is in sharp contrast to those of air, yet airborne microbes are thought to have significant impacts on many aspects of our lives from their potential roles in atmospheric events such as cloud formation, precipitation, and atmospheric chemistry to their major impact on human health. In this review, we will discuss the current progress in airborne metagenomics, with a special focus on exploring the challenges and opportunities of undertaking such studies. The main challenges of conducting metagenomic studies of airborne microbes are as follows: 1) Low density of microorganisms in the air, 2) efficient retrieval of microorganisms from the air, 3) variability in airborne microbial community composition, 4) the lack of standardized protocols and methodologies, and 5) DNA sequencing and bioinformatics-related challenges. Overcoming these challenges could provide the groundwork for comprehensive analysis of airborne microbes and their potential impact on the atmosphere, global climate, and our health. Metagenomic studies offer a unique opportunity to examine viral and bacterial diversity in the air and monitor their spread locally or across the globe, including threats from pathogenic microorganisms. Airborne metagenomic studies could also lead to discoveries of novel genes and metabolic pathways relevant to meteorological and industrial applications, environmental bioremediation, and biogeochemical cycles. PMID:25953766

The NASA Langley High Altitude Lidar Observatory (HALO) - Advancements in Airborne DIAL Measurements of CH4 and H2O

NASA Astrophysics Data System (ADS)

Nehrir, A. R.; Hair, J. W.; Ferrare, R. A.; Hostetler, C. A.; Notari, A.; Collins, J. E., Jr.; Hare, R. J.; Harper, D. B.; Antill, C.; Cook, A. L.; Young, J.; Chuang, T.; Welch, W.

2016-12-01

Atmospheric methane (CH4) has the second largest radiative forcing of the long-lived greenhouse gasses (GHG) after carbon dioxide. However, methane's much shorter atmospheric lifetime and much stronger warming potential make its radiative forcing equivalent to that for CO2 over a 20-year time horizon which makes CH4 a particularly attractive target for mitigation strategies. Similar to CH4, water vapor (H2O) is the most dominant of the short-lived GHG in the atmosphere and plays a key role in many atmospheric processes. Atmospheric H2O concentrations span over four orders of magnitude from the planetary boundary layer where high impact weather initiates to lower levels in the upper troposphere and lower stratosphere where water vapor has significant and long term impacts on the Earth's radiation budget. Active remote sensing employing the differential absorption lidar (DIAL) technique enables scientific assessments of both natural and anthropogenic sources and sinks of CH4 with high accuracy and precision as well as and its impacts on the climate. The DIAL technique also allows for profiling of tropospheric water vapor for weather and climate applications with unprecedented spatial and temporal resolution. NASA Langley is developing the High Altitude Lidar Observatory (HALO) lidar system to address the observational needs of NASA's weather, climate, carbon cycle, and atmospheric composition focus areas. HALO is a multi-function airborne lidar being developed to measure atmospheric H2O and CH4 mixing ratios and aerosol and cloud optical properties using the DIAL and High Spectral Resolution Lidar (HSRL) techniques, respectively. HALO is designed as an airborne simulator for future space based DIAL missions and will serve as test bed for risk reduction of key technologies required of future space based GHG DIAL missions. A system level overview and up-to-date progress of the HALO lidar will be presented. Simulations on the expected accuracy and precision of HALO CH4

Aspects regarding vertical distribution of greenhouse gases resulted from in situ airborne measurements

NASA Astrophysics Data System (ADS)

Boscornea, Andreea; Sorin Vajaiac, Nicolae; Ardelean, Magdalena; Benciu, Silviu Stefan

2016-04-01

In the last decades the air quality, as well as other components of the environment, has been severely affected by uncontrolled emissions of gases - most known as greenhouse gases (GHG). The main role of GHG is given by the direct influence on the Earth's radiative budget, through Sun light scattering and indirectly by participating in cloud formation. Aldo, many efforts were made for reducing the high levels of these pollutants, e.g., International Panel on Climate Change (IPCC) initiatives, Montreal Protocol, etc., this issue is still open. In this context, this study aims to present several aspects regarding the vertical distribution in the lower atmosphere of some greenhouse gases: water vapours, CO, CO2 and methane. Bucharest and its metropolitan area is one of the most polluted regions of Romania due to high traffic. For assessing the air quality of this area, in situ measurements of water vapours, CO, CO2 and CH4 were performed using a Britten Norman Islander BN2 aircraft equipped with a Picarro gas analyser, model G2401-mc, able to provide precised, continuous and accurate data in real time. This configuration consisting in aircraft and airborne instruments was tested for the first time in Romania. For accomplishing the objectives of the measurement campaign, there were proposed several flight strategies which included vertical and horizontal soundings from 105 m to 3300 m and vice-versa around Clinceni area (20 km West of Bucharest). During 5 days (25.08.2015 - 31.08.2015) were performed 7 flights comprising 10h 18min research flight hours. The measured concentrations of GHS ranged between 0.18 - 2.2 ppm for water vapours with an average maximum value of 1.7 ppm, 0.04 - 0.53 ppm for CO with an average maximum value of 0.21 ppm, 377 - 437.5 ppm for CO2 with an average maximum value of 397 ppm and 1.7 - 6.1 ppm for CH4 with an average maximum value of 2.195 ppm. It was noticed that measured concentrations of GHG are decreasing for high values of sounding

Airborne Microalgae: Insights, Opportunities, and Challenges

PubMed Central

Skjøth, Carsten Ambelas; Šantl-Temkiv, Tina; Löndahl, Jakob

2016-01-01

Airborne dispersal of microalgae has largely been a blind spot in environmental biological studies because of their low concentration in the atmosphere and the technical limitations in investigating microalgae from air samples. Recent studies show that airborne microalgae can survive air transportation and interact with the environment, possibly influencing their deposition rates. This minireview presents a summary of these studies and traces the possible route, step by step, from established ecosystems to new habitats through air transportation over a variety of geographic scales. Emission, transportation, deposition, and adaptation to atmospheric stress are discussed, as well as the consequences of their dispersal on health and the environment and state-of-the-art techniques to detect and model airborne microalga dispersal. More-detailed studies on the microalga atmospheric cycle, including, for instance, ice nucleation activity and transport simulations, are crucial for improving our understanding of microalga ecology, identifying microalga interactions with the environment, and preventing unwanted contamination events or invasions. PMID:26801574

Airborne Observations of Water Vapor Deuterium Excess in the Mid-Latitude Lower Troposphere

NASA Astrophysics Data System (ADS)

Salmon, O. E.; Welp, L.; Shepson, P. B.; Stirm, B. H.

2017-12-01

Water vapor is responsible for over half of the natural atmospheric greenhouse effect. As global temperatures increase due to fossil fuel combustion, atmospheric water vapor concentrations are also expected to increase in positive feedback. Additionally, studies have shown that urban areas can influence humidity levels, and the frequency and intensity of precipitation events. It is thus important to understand anthropogenic modification of the hydrological cycle, particularly around urban areas, where over half of the world's population resides. Airborne measurements of water vapor isotopologues containing 2H and 18O were conducted to better understand processes influencing atmospheric moisture levels around urban areas. Airborne measurements were conducted around the Indianapolis and Washington, D.C.-Baltimore areas during afternoon hours in February and March 2016, using a Los Gatos Research Water Vapor Isotope Analyzer installed in Purdue University's experimental aircraft, the Airborne Laboratory for Atmospheric Research. The measurements of 2H and 18O allow for the calculation of deuterium excess (= δ2H - 8*δ18O), which provides information about non-equilibrium processes, such as kinetic effects, air parcel mixing, and transpiration. There are few studies that have reported observations of deuterium excess above the surface level ( 100 m). During the measurement campaign, vertical profiles were frequently conducted from 300 m above the ground to an altitude of approximately 1.5 km, effectively characterizing water vapor isotope profiles spanning the boundary layer and lower free troposphere. Measurements probed the transition from planetary boundary layer air to free troposphere air to provide high resolution deuterium excess information across this interface. Processes such as Rayleigh distillation, atmospheric mixing, and surface fluxes potentially impacting water vapor deuterium excess through the boundary layer and free troposphere with be discussed.

Differential absorption lidar measurements of atmospheric temperature and pressure profiles

NASA Technical Reports Server (NTRS)

Korb, C. L.

1981-01-01

The theory and methodology of using differential absorption lidar techniques for the remote measurement of atmospheric pressure profiles, surface pressure, and temperature profiles from ground, air, and space-based platforms are presented. Pressure measurements are effected by means of high resolution measurement of absorption at the edges of the oxygen A band lines where absorption is pressure dependent due to collisional line broadening. Temperature is assessed using measurements of the absorption at the center of the oxygen A band line originating from a quantum state with high ground state energy. The population of the state is temperature dependent, allowing determination of the temperature through the Boltzmann term. The results of simulations of the techniques using Voigt profile and variational analysis are reported for ground-based, airborne, and Shuttle-based systems. Accuracies in the 0.5-1.0 K and 0.1-0.3% range are projected.

Sampling the Vertical Moisture Structure of an Atmospheric River Event Using Airborne GPS Radio Occultation Profiling

NASA Astrophysics Data System (ADS)

Haase, J. S.; Malloy, K.; Murphy, B.; Sussman, J.; Zhang, W.

2015-12-01

Atmospheric rivers (ARs) are of high concern in California, bringing significant rain to the region over extended time periods of up to 5 days, potentially causing floods, and more importantly, contributing to the Sierra snowpack that provides much of the regional water resources. The CalWater project focuses on predicting the variability of the West Coast water supply, including improving AR forecasting. Unfortunately, data collection over the ocean remains a challenge and impacts forecasting accuracy. One novel technique to address this issue includes airborne GPS radio occultation (ARO), using broadcast GPS signals from space to measure the signal ray path bending angle and refractivity to retrieve vertical water vapor profiles. The Global Navigation Satellite System Instrument System for Multistatic and Occultation Sensing (GISMOS) system was developed for this purpose for recording and processing high-sample rate (10MHz) signals in the lower troposphere. Previous studies (Murphy et al, 2014) have shown promising results in acquiring airborne GPS RO data, comparing it to dropsondes and numerical weather models. CalWater launched a field campaign in the beginning of 2015 which included testing GISMOS ARO on the NOAA GIV aircraft for AR data acquisition, flying into the February 6th AR event that brought up to 35 cm of rain to central California. This case study will compare airborne GPS RO refractivity profiles to the NCEP-NCAR final reanalysis model and dropsonde profiles. We will show the data distribution and explain the sampling characteristics, providing high resolution vertical information to the sides of the aircraft in a manner complementary to dropsondes beneath the flight track. We will show how this method can provide additional reliable data during the development of AR storms.

Airborne measurements of multi-wavelength aerosol optical depth and cloud-transmitted radiances in the North Atlantic Aerosols and Marine Ecosystems Study (NAAMES)

NASA Astrophysics Data System (ADS)

Shinozuka, Y.; Johnson, R. R.; LeBlanc, S. E.; Chang, C. S.; Redemann, J.

2016-12-01

We report on our recent airborne measurements of multi-wavelength aerosol optical depth and cloud-transmitted radiances over the North Atlantic. We ran the Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) in November 2015 and the 14-channel Ames Airborne Tracking Sunphotometer (AATS-14) in May and June 2016, both aboard the NASA C-130 aircraft. These sunphotometers provide measurements of overlying cirrus and aerosol optical depths of up to about 0.5 and constrain ecosystem and aerosol retrievals from the accompanying nadir-viewing remote sensing instruments. In addition, 4STAR measures hyperspectral transmitted light, which enables the retrieval of cloud optical depth, effective radius, and thermodynamic phase from below cloud. Our measurements contribute to the science objectives of the North Atlantic Aerosols and Marine Ecosystems Study (NAAMES), an interdisciplinary investigation resolving key processes controlling marine ecosystems and aerosols that are essential to our understanding of Earth system function and future change.

Observations with the GISMOS Airborne Radio Occultation System

NASA Astrophysics Data System (ADS)

Muradyan, Paytsar; Haase, Jennifer; Garrison, James; Lulich, Tyler; Xie, Feiqin

2010-05-01

The spatial sample density of temperature and moisture profiles derived from the current spaceborne GPS radio occultation (RO) constellation is limited by the number of occultation satellites in operation. With the current RO satellite configuration, only one RO profile per day is typically available in a 160,000 square kilometer area in the mid-latitude and tropics and slightly more in high latitudes. The airborne RO technique, which has the GPS receiver onboard an airplane, offers flexibility and much denser sampling for targeted observation within 400 km of the aircraft, and provides comparable high vertical resolution to that of the spaceborne case. With an airborne system, targeted measurements can be planned in an optimal geometry to study the accuracy of RO measurements in the lower troposphere where strong vertical gradients in moisture might lead to disruption of signal tracking. These dense measurements can also be used to test assimilation techniques of refractivity and lower tropospheric moisture derived from RO data. In February 2008, the GNSS Instrument System for Multistatic and Occultation Sensing (GISMOS), developed at Purdue University, was successfully deployed on the NSF HIAPER aircraft for series of research flights in the Gulf of Mexico coastal region to validate the airborne observing system. During this campaign, occultation observations were collected in conjunction with supplemental radiosonde and dropsonde soundings. RO signals were recorded using side-looking GPS antennas and dual frequency GPS receivers. However, these conventional phase-locked-loop GPS receivers cannot always track the signal in the lower troposphere, where there are rapid phase accelerations caused by highly variable moisture structures. To extend the observations deeper into the atmosphere, the raw signal from occulting satellites is recorded at 10MHz sampling interval by a GPS recording system (GRS). Open-loop (OL) tracking, which replaces the traditional GPS

Integrated Airborne and In-Situ Measurements Over Land-Fast Ice Near Barrow, AK.

NASA Astrophysics Data System (ADS)

Gardner, J. M.; Brozena, J. M.; Richter-Menge, J.; Abelev, A.; Liang, R.; Ball, D.; Claffey, K. J.; Hebert, D. A.; Jones, K.

2015-12-01

The Naval Research Laboratory has collected two field seasons of integrated airborne and in-situ measurements over multiple sites of floating, but land-fast ice north of Barrow, AK. During the first season in March of 2014 the Cold Regions Research and Engineering Laboratory led the on-ice group including NRL personnel and Naval Academy midshipmen. The second season (March 2015) included only NRL scientists and midshipmen. The in-situ data provided ground-truth for airborne measurements from a scanning LiDAR (Riegl Q 560i), digital photogrammetry (Applanix DSS-439), a low-frequency SAR (P-band in 2014 and P and L bands in 2015) and a snow/Ku radar procured from the Center for Remote Sensing of Ice Sheets of the University of Kansas. The CReSIS radar was updated in 2015 to integrate the snow and Ku radars into a single continuous chirp, thus improving resolution. The objective of the survey was to aid our understanding of the use of the airborne data to calibrate/validate Cryosat-2 data. Sampling size or "footprint" plays a critical role in the attempt to compare in-situ measurements with airborne (or satellite) measurements. Thus the in-situ data were arranged to minimize aliasing. Ground measurements were collected along transects a sites generally consisting of a 2 km long profile of Magnaprobe and EM31 measurements with periodic boreholes. A 60 m x 400 m swath of Magnaprobe measurements was centered on this profile. Airborne data were collected on multiple overflights of the transect areas. The LiDAR measured total freeboard (ice + snow) referenced to leads in the ice, and produced swaths 200-300 m wide. The SAR imaged the ice beneath the snow and the snow/Ku radar measured snow thickness. The freeboard measurements and snow thickness are used to estimate ice thickness via isostasy and density estimates. Comparisons and processing methodology will be shown. The results of this ground-truth experiment will inform our analysis of grids of airborne data collected

Validating MODIS above-cloud aerosol optical depth retrieved from "color ratio" algorithm using direct measurements made by NASA's airborne AATS and 4STAR sensors

NASA Astrophysics Data System (ADS)

Jethva, Hiren; Torres, Omar; Remer, Lorraine; Redemann, Jens; Livingston, John; Dunagan, Stephen; Shinozuka, Yohei; Kacenelenbogen, Meloe; Segal Rosenheimer, Michal; Spurr, Rob

2016-10-01

We present the validation analysis of above-cloud aerosol optical depth (ACAOD) retrieved from the "color ratio" method applied to MODIS cloudy-sky reflectance measurements using the limited direct measurements made by NASA's airborne Ames Airborne Tracking Sunphotometer (AATS) and Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) sensors. A thorough search of the airborne database collection revealed a total of five significant events in which an airborne sun photometer, coincident with the MODIS overpass, observed partially absorbing aerosols emitted from agricultural biomass burning, dust, and wildfires over a low-level cloud deck during SAFARI-2000, ACE-ASIA 2001, and SEAC4RS 2013 campaigns, respectively. The co-located satellite-airborne matchups revealed a good agreement (root-mean-square difference < 0.1), with most matchups falling within the estimated uncertainties associated the MODIS retrievals (about -10 to +50 %). The co-retrieved cloud optical depth was comparable to that of the MODIS operational cloud product for ACE-ASIA and SEAC4RS, however, higher by 30-50 % for the SAFARI-2000 case study. The reason for this discrepancy could be attributed to the distinct aerosol optical properties encountered during respective campaigns. A brief discussion on the sources of uncertainty in the satellite-based ACAOD retrieval and co-location procedure is presented. Field experiments dedicated to making direct measurements of aerosols above cloud are needed for the extensive validation of satellite-based retrievals.

Validating MODIS Above-Cloud Aerosol Optical Depth Retrieved from Color Ratio Algorithm Using Direct Measurements Made by NASA's Airborne AATS and 4STAR Sensors

NASA Technical Reports Server (NTRS)

Jethva, Hiren; Torres, Omar; Remer, Lorraine; Redemann, Jens; Livingston, John; Dunagan, Stephen; Shinozuka, Yohei; Kacenelenbogen, Meloe; Segal Rozenhaimer, Michal; Spurr, Rob

2016-01-01

We present the validation analysis of above-cloud aerosol optical depth (ACAOD) retrieved from the color ratio method applied to MODIS cloudy-sky reflectance measurements using the limited direct measurements made by NASAs airborne Ames Airborne Tracking Sunphotometer (AATS) and Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) sensors. A thorough search of the airborne database collection revealed a total of five significant events in which an airborne sun photometer, coincident with the MODIS overpass, observed partially absorbing aerosols emitted from agricultural biomass burning, dust, and wildfires over a low-level cloud deck during SAFARI-2000, ACE-ASIA 2001, and SEAC4RS 2013 campaigns, respectively. The co-located satellite-airborne match ups revealed a good agreement (root-mean-square difference less than 0.1), with most match ups falling within the estimated uncertainties associated with the MODIS retrievals (about -10 to +50 ). The co-retrieved cloud optical depth was comparable to that of the MODIS operational cloud product for ACE-ASIA and SEAC4RS, however, higher by 30-50% for the SAFARI-2000 case study. The reason for this discrepancy could be attributed to the distinct aerosol optical properties encountered during respective campaigns. A brief discussion on the sources of uncertainty in the satellite-based ACAOD retrieval and co-location procedure is presented. Field experiments dedicated to making direct measurements of aerosols above cloud are needed for the extensive validation of satellite based retrievals.

Analysis of satellite and airborne wind measurements during the SEMAPHORE experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tournadre, J.; Hauser, D.

1994-12-31

During the SEMAPHORE experiment Intensive Observation Period (IOP), held in October and November 1993 in the Azores-Madeira region, two airplanes, instrumented for atmospheric research, and two oceanographic research vessels have conducted in situ measurements in a 500km x 500km domain. Within the framework of SEMAPHORE, the SOFIA program is dedicated to the study of the air-sea fluxes and interactions from local scale up to mesoscale. The analysis of the structure of the wind and wave fields and their relations to the surface fluxes (especially near oceanic fronts) and the validation of the satellite data are two of the main goalsmore » of the SOFIA program. During the IOP, the experiment domain was regularly overflown by the ERS-1 and Topex-Poseidon (TP) satellites. This study presents a preliminary analysis of the ERS-1 and TP altimeter wind and wave measurement and ERS-1 scatterometer wind fields. The data from the airborne RESSAC (a radar ocean wave spectrometer) are also presented.« less

Challenges and opportunities of airborne metagenomics.

PubMed

Behzad, Hayedeh; Gojobori, Takashi; Mineta, Katsuhiko

2015-05-06

Recent metagenomic studies of environments, such as marine and soil, have significantly enhanced our understanding of the diverse microbial communities living in these habitats and their essential roles in sustaining vast ecosystems. The increase in the number of publications related to soil and marine metagenomics is in sharp contrast to those of air, yet airborne microbes are thought to have significant impacts on many aspects of our lives from their potential roles in atmospheric events such as cloud formation, precipitation, and atmospheric chemistry to their major impact on human health. In this review, we will discuss the current progress in airborne metagenomics, with a special focus on exploring the challenges and opportunities of undertaking such studies. The main challenges of conducting metagenomic studies of airborne microbes are as follows: 1) Low density of microorganisms in the air, 2) efficient retrieval of microorganisms from the air, 3) variability in airborne microbial community composition, 4) the lack of standardized protocols and methodologies, and 5) DNA sequencing and bioinformatics-related challenges. Overcoming these challenges could provide the groundwork for comprehensive analysis of airborne microbes and their potential impact on the atmosphere, global climate, and our health. Metagenomic studies offer a unique opportunity to examine viral and bacterial diversity in the air and monitor their spread locally or across the globe, including threats from pathogenic microorganisms. Airborne metagenomic studies could also lead to discoveries of novel genes and metabolic pathways relevant to meteorological and industrial applications, environmental bioremediation, and biogeochemical cycles. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Measurements of Atmospheric CO2 Column in Cloudy Weather Conditions using An IM-CW Lidar at 1.57 Micron

NASA Technical Reports Server (NTRS)

Lin, Bing; Obland, Michael; Harrison, F. Wallace; Nehrir, Amin; Browell, Edward; Campbell, Joel; Dobler, Jeremy; Meadows, Bryon; Fan, Tai-Fang; Kooi, Susan;

Approach to the characterization of the airborne organic matter (benzene soluble) in the atmosphere of Mexico City

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bravo, H.; Baez, A.P.

1961-01-01

Three areas of Mexico City were chosen from which to obtain samples of aromatic airborne particles. The samples were analyzed in order to have a broad idea of the composition of the material. The downtown area contained the highest concentration of organic benzene soluble material in the airborne particles, with the highest concentrations during the winter months. A combined sample (Ciudad Universitaria and Tacuba) was analyzed and gave the following figures of benzene soluble material in mg/g: fluoranthene - 160; pyrene - 210; benzo(a)anthracene - 47; benzo(a)pyrene - 82; benzo(e)pyrene - 150; benzo(g,h,i)perylene - 340; coronene - 160. A moremore » complete study is recommended in order to establish the actual parameters of the organic content in Mexico City's atmosphere.« less

Airborne particulate matter in spacecraft

NASA Technical Reports Server (NTRS)

1988-01-01

Acceptability limits and sampling and monitoring strategies for airborne particles in spacecraft were considered. Based on instances of eye and respiratory tract irritation reported by Shuttle flight crews, the following acceptability limits for airborne particles were recommended: for flights of 1 week or less duration (1 mg/cu m for particles less than 10 microns in aerodynamic diameter (AD) plus 1 mg/cu m for particles 10 to 100 microns in AD); and for flights greater than 1 week and up to 6 months in duration (0.2 mg/cu m for particles less than 10 microns in AD plus 0.2 mg/cu m for particles 10 to 100 microns in AD. These numerical limits were recommended to aid in spacecraft atmosphere design which should aim at particulate levels that are a low as reasonably achievable. Sampling of spacecraft atmospheres for particles should include size-fractionated samples of 0 to 10, 10 to 100, and greater than 100 micron particles for mass concentration measurement and elementary chemical analysis by nondestructive analysis techniques. Morphological and chemical analyses of single particles should also be made to aid in identifying airborne particulate sources. Air cleaning systems based on inertial collection principles and fine particle collection devices based on electrostatic precipitation and filtration should be considered for incorporation into spacecraft air circulation systems. It was also recommended that research be carried out in space in the areas of health effects and particle characterization.

Bio-organic materials in the atmosphere and snow: measurement and characterization.

PubMed

Ariya, P A; Kos, G; Mortazavi, R; Hudson, E D; Kanthasamy, V; Eltouny, N; Sun, J; Wilde, C

2014-01-01

Bio-organic chemicals are ubiquitous in the Earth's atmosphere and at air-snow interfaces, as well as in aerosols and in clouds. It has been known for centuries that airborne biological matter plays various roles in the transmission of disease in humans and in ecosystems. The implication of chemical compounds of biological origins in cloud condensation and in ice nucleation processes has also been studied during the last few decades, and implications have been suggested in the reduction of visibility, in the influence on oxidative potential of the atmosphere and transformation of compounds in the atmosphere, in the formation of haze, change of snow-ice albedo, in agricultural processes, and bio-hazards and bio-terrorism. In this review we critically examine existing observation data on bio-organic compounds in the atmosphere and in snow. We also review both conventional and cutting-edge analytical techniques and methods for measurement and characterisation of bio-organic compounds and specifically for microbial communities, in the atmosphere and snow. We also explore the link between biological compounds and nucleation processes. Due to increased interest in decreasing emissions of carbon-containing compounds, we also briefly review (in an Appendix) methods and techniques that are currently deployed for bio-organic remediation.

Airborne cloud condensation nuclei measurements during the 2006 Texas Air Quality Study

NASA Astrophysics Data System (ADS)

Asa-Awuku, Akua; Moore, Richard H.; Nenes, Athanasios; Bahreini, Roya; Holloway, John S.; Brock, Charles A.; Middlebrook, Ann M.; Ryerson, Thomas B.; Jimenez, Jose L.; Decarlo, Peter F.; Hecobian, Arsineh; Weber, Rodney J.; Stickel, Robert; Tanner, Dave J.; Huey, Lewis G.

2011-06-01

Airborne measurements of aerosol and cloud condensation nuclei (CCN) were conducted aboard the National Oceanic and Atmospheric Administration WP-3D platform during the 2006 Texas Air Quality Study/Gulf of Mexico Atmospheric Composition and Climate Study (TexAQS/GoMACCS). The measurements were conducted in regions influenced by industrial and urban sources. Observations show significant local variability of CCN activity (CCN/CN from 0.1 to 0.5 at s = 0.43%), while variability is less significant across regional scales (˜100 km × 100 km; CCN/CN is ˜0.1 at s = 0.43%). CCN activity can increase with increasing plume age and oxygenated organic fraction. CCN measurements are compared to predictions for a number of mixing state and composition assumptions. Mixing state assumptions that assumed internally mixed aerosol predict CCN concentrations well. Assuming organics are as hygroscopic as ammonium sulfate consistently overpredicted CCN concentrations. On average, the water-soluble organic carbon (WSOC) fraction is 60 ± 14% of the organic aerosol. We show that CCN closure can be significantly improved by incorporating knowledge of the WSOC fraction with a prescribed organic hygroscopicity parameter (κ = 0.16 or effective κ ˜ 0.3). This implies that the hygroscopicity of organic mass is primarily a function of the WSOC fraction. The overall aerosol hygroscopicity parameter varies between 0.08 and 0.88. Furthermore, droplet activation kinetics are variable and 60% of particles are smaller than the size characteristic of rapid droplet growth.

Satellite Observations for Detecting and Tracking Changes in Atmospheric Composition

EPA Science Inventory

The international scientific community's Integrated Global Atmosphere Chemistry Observation System report outlined a plan for ground-based, airborne and satellite Measurements, and models to integrate the observations into a 4-dimensional representation of the atmosphere (space a...

Studying the influence of temperature and pressure on microphysical properties of mixed-phase clouds using airborne measurements

NASA Astrophysics Data System (ADS)

Andreea, Boscornea; Sabina, Stefan; Sorin-Nicolae, Vajaiac; Mihai, Cimpuieru

2015-04-01

One cloud type for which the formation and evolution process is not well-understood is the mixed-phase type. In general mixed-phase clouds consist of liquid droplets and ice crystals. The temperature interval within both liquid droplets and ice crystals can potentially coexist is limited to 0 °C and - 40 °C. Mixed-phase clouds account for 20% to 30% of the global cloud coverage. The need to understand the microphysical characteristics of mixed-phase clouds to improve numerical forecast modeling and radiative transfer calculation is of major interest in the atmospheric community. In the past, studies of cloud phase composition have been significantly limited by a lack of aircraft instruments capable of discriminating between the ice and liquid phase for a wide range of particle sizes. Presently, in situ airborne measurements provide the most accurate information about cloud microphysical characteristics. This information can be used for verification of both numerical models and cloud remote-sensing techniques. The knowledge of the temperature and pressure variation during the airborne measurements is crucial in order to understand their influence on the cloud dynamics and also their role in the cloud formation processes like accretion and coalescence. Therefore, in this paper is presented a comprehensive study of cloud microphysical properties in mixed-phase clouds in focus of the influence of temperature and pressure variation on both, cloud dynamics and the cloud formation processes, using measurements performed with the ATMOSLAB - Airborne Laboratory for Environmental Atmospheric Research in property of the National Institute for Aerospace Research "Elie Carafoli" (INCAS). The airborne laboratory equipped for special research missions is based on a Hawker Beechcraft - King Air C90 GTx aircraft and is equipped with a sensors system CAPS - Cloud, Aerosol and Precipitation Spectrometer (30 bins, 0.51-50 µm) and a HAWKEYE cloud probe. The analyzed data in this

Airborne Measurements of Ozone and Other Trace Gases Captured by the Alpha Jet Atmospheric eXperiment (AJAX) during the 2016 California Baseline Ozone Transport Study (CABOTS)

NASA Astrophysics Data System (ADS)

McNamara, M. E.; Iraci, L. T.; Yates, E. L.; Marrero, J. E.; Ryoo, J. M.; Langford, A. O.; Alvarez, R. J., II; Senff, C. J.; Kirgis, G.; Chiao, S.; Eiserloh, A. J., Jr.

2016-12-01

In October 2015, the Environmental Protection Agency lowered the National Ambient Air Quality Standard for ozone (O3) from 75 ppbv to 70 ppbv. However, meeting the stricter air standards is a challenge for certain areas of California, like the San Joaquin Valley (SJV), where O3 levels are typically high due to topography, meteorology, and local emissions. Another factor potentially contributing to increased surface O3 is the trans-Pacific transport of O3 from Asia. The extent of which O3stems from local emissions or is transported across the Pacific, however, is unclear. The California Ozone Transport Study (CABOTS), a joint effort between the California Air Resource Board, the National Oceanic and Atmospheric Administration, and San Jose State University, was conducted during the spring and summer of 2016 in an attempt to answer this question. Nearly 10 science flights were carried out by the Alpha Jet Atmospheric eXperiment (AJAX) between June and August 2016, based out of the NASA Ames Research Center. A summary of airborne O3, CO2, CH4, H2O, formaldehyde (HCHO), and 3D wind measurements will be presented. AJAX flights connect the fixed-location measurements at Visalia (TOPAZ ozone lidar) and Bodega Bay (ozonesondes), while exploring the spatial heterogeneity of O3 concentrations across California and at various offshore locations. Preliminary analyses of these flights will investigate connections between offshore O3 and Central Valley O3. Vertical profiles, time series, and tracer-tracer correlations will be employed to identify the sources of O3 during these flights.

Airborne data measurement system errors reduction through state estimation and control optimization

NASA Astrophysics Data System (ADS)

Sebryakov, G. G.; Muzhichek, S. M.; Pavlov, V. I.; Ermolin, O. V.; Skrinnikov, A. A.

2018-02-01

The paper discusses the problem of airborne data measurement system errors reduction through state estimation and control optimization. The approaches are proposed based on the methods of experiment design and the theory of systems with random abrupt structure variation. The paper considers various control criteria as applied to an aircraft data measurement system. The physics of criteria is explained, the mathematical description and the sequence of steps for each criterion application is shown. The formula is given for airborne data measurement system state vector posterior estimation based for systems with structure variations.

Airborne remote-sensing of atmospheric CH4 and CO2 with MAMap: first results of measurements over wetlands in Germany and a N-S transect from Canada to Chile

NASA Astrophysics Data System (ADS)

Tretner, A.; Gerilowski, K.; Bovensmann, H.; Buchwitz, M.; Bertagnolio, P. P.; Erzinger, J.; Burrows, J.

2008-12-01

The Methane Airborne Mapper (MAMap) was designed for CO2 and CH4 remote sensing of the atmospheric column between an aircraft and the Earth's surface. The instrument is specified to detect mixing ratio variations below the aircraft of <3% of the atmospheric background as well as a ground pixel size of 20m x 20m (700m flight height, 200 km/h flight speed). It allows the detection of CO2 and CH4 gradients on a local, regional and global scale, and provides a link between ground-based and satellite- based measurements. The goal of the MAMap measurements is to improve the knowledge of CH4 and CO2 sources and sinks. In 2007 and 2008, several flight campaigns over bogs and wetlands have been conducted in Germany and correlated to ground-based measurements. A first version of the data retrieval has been developed using a modified version of the WFM-DOAS algorithm. WFM-DOAS is also used for the retrieval of CH4 and CO2 column concentrations from nadir measurements by SCIAMACHY onboard ENVISAT. In November 2008, a transect from Oshawa, Canada to Punta Arenas, Chile will be flown onboard the AWI POLAR 5 aircraft. Along the flight path CH4 and CO2 measurements will be conducted by MAMap. Besides the N-S track (Canada-USA-Bahamas-Panama-Ecuador-Peru-Chile), an additional W-E track from Guayaquil (Ecuador) to Iquitos (Peru) and back is planned, covering large areas of Peruvian rainforest. One focus of this project is the evaluation of tropical rain forest and savannah as sources/sinks of CH4 and CO2. Discrepancies between the models and satellite data regarding atmospheric CH4 concentrations over the tropics have been reported in the past. A first assessment of MAMap measurements performed in 2008 over wetlands in Germany and the AWI-POLAR 5 campaign will be presented.

Assessment of airborne soy-hull allergen (Gly m 1) in the Port of Ancona, Italy.

PubMed

Antonicelli, L; Ruello, M L; Monsalve, R I; González, R; Fava, G; Bonifazi, F

2010-10-01

Epidemic asthma outbreaks are potentially a very high-risk medical situation in seaport towns where large volumes of soybean are loaded and unloaded Airborne allergen assessment plays a pivotal role in evaluating the resulting environmental pollution. The aim of this study was to measure the airborne Gly m 1 allergen level in the seaport of Ancona in order assess the soybean-specific allergenic risk for the city. Allergen and PM10 were evaluated at progressive distances from the port area. Allergen analysis was performed by monoclonal antibody-based immunoassay on the sampled filters. Daily meteorological data were obtained from the local meteorological station. For estimating the assimilative capacity of the atmosphere, an approach based on dispersive ventilation coefficient was tried. The allergen concentrations detected were low (range = 0.4-171 ng/m3). A decreasing gradient of the airborne allergen from the unloading area (22.1 +/- 41.2 ng/m3) to the control area (0.6 +/- 0.7 ng/m3) was detected. The concentration of the airborne Gly m 1 was not coupled with the presence of the soy-carrying ships in the port. A statistically significant relationship between airborne allergen, PM10 and local meteorological parameters quantifies the association with the atmospheric condition. Airborne Gly m 1 is part of the atmospheric dust of Ancona. The low level of this allergen seems consistent with the absence of asthma epidemic outbreak.

Initial evaluation of airborne water vapour measurements by the IAGOS-GHG CRDS system

NASA Astrophysics Data System (ADS)

Filges, Annette; Gerbig, Christoph; Smit, Herman G. J.; Krämer, Martina; Spelten, Nicole

2013-04-01

Accurate and reliable airborne measurements of water vapour are still a challenge. Presently, no airborne humidity sensor exists that covers the entire range of water vapour content between the surface and the upper troposphere/lower stratosphere (UT/LS) region with sufficient accuracy and time resolution. Nevertheless , these data are a pre-requisite to study the underlying processes in the chemistry and physics of the atmosphere. The DENCHAR project (Development and Evaluation of Novel Compact Hygrometer for Airborne Research) addresses this deficit by developing and characterizing novel or improved compact airborne hygrometers for different airborne applications within EUFAR (European Facility for Airborne Research). As part of the DENCHAR inter-comparison campaign in Hohn (Germany), 23 May - 1 June 2011, a commercial gas analyzer (G2401-m, Picarro Inc.,US), based on cavity ring-down spectroscopy (CRDS), was installed on a Learjet to measure water vapour, CO2, CH4 and CO. The CRDS components are identical to those chosen for integration aboard commercial airliner within IAGOS (In-service Aircraft for a Global Observing System). Thus the campaign allowed for the initial assessment validation of the long-term IAGOS H2O measurements by CRDS against reference instruments with a long performance record (FISH, the Fast In-situ Stratospheric Hygrometer, and CR2 frostpoint hygrometer, both research centre Juelich). The inlet system, a one meter long 1/8" FEP-tube connected to a Rosemount TAT housing (model 102BX, deiced) installed on a window plate of the aircraft, was designed to eliminate sampling of larger aerosols, ice particles, and water droplets, and provides about 90% of ram-pressure. In combination with a lowered sample flow of 0.1 slpm (corresponding to a 4 second response time), this ensured a fully controlled sample pressure in the cavity of 140 torr throughout an aircraft altitude operating range up to 12.5 km without the need of an upstream sampling pump

Water depth measurement using an airborne pulsed neon laser system

NASA Technical Reports Server (NTRS)

Hoge, F. E.; Swift, R. N.; Frederick, E. B.

1980-01-01

The paper presents the water depth measurement using an airborne pulsed neon laser system. The results of initial base-line field test results of NASA airborne oceanographic lidar in the bathymetry mode are given, with water-truth measurements of depth and beam attenuation coefficients by boat taken at the same time as overflights to aid in determining the system's operational performance. The nadir-angle tests and field-of-view data are presented; this laser bathymetry system is an improvement over prior models in that (1) the surface-to-bottom pulse waveform is digitally recorded on magnetic tape, and (2) wide-swath mapping data may be routinely acquired using a 30 deg full-angle conical scanner.

Comparison of airborne lidar measurements with 420 kHz echo-sounder measurements of zooplankton.

PubMed

Churnside, James H; Thorne, Richard E

2005-09-10

Airborne lidar has the potential to survey large areas quickly and at a low cost per kilometer along a survey line. For this reason, we investigated the performance of an airborne lidar for surveys of zooplankton. In particular, we compared the lidar returns with echo-sounder measurements of zooplankton in Prince William Sound, Alaska. Data from eight regions of the Sound were compared, and the correlation between the two methods was 0.78. To obtain this level of agreement, a threshold was applied to the lidar return to remove the effects of scattering from phytoplankton.

Measurements of airborne methylene diphenyl diisocyanate (MDI) concentration in the U.S. workplace.

PubMed

Booth, Karroll; Cummings, Barbara; Karoly, William J; Mullins, Sharon; Robert, William P; Spence, Mark; Lichtenberg, Fran W; Banta, J

2009-04-01

This article summarizes a large body of industry air sampling data (8134 samples) in which airborne MDI concentrations were measured in a wide variety of manufacturing processes that use either polymeric MDI (PMDI) or monomeric (pure) MDI. Data were collected during the period 1984 through 1999. A total of 606 surveys were conducted for 251 companies at 317 facilities. The database includes 3583 personal (breathing zone) samples and 4551 area samples. Data demonstrate that workplace airborne MDI concentrations are extremely low in a majority of the manufacturing operations. Most (74.6%) of the airborne MDI concentrations measured in the personal samples were nondetectable, i.e., below the limits of quantification (LOQs). A variety of validated industrial hygiene sampling/analytical methods were used for data collection; most are modifications of OSHA Method 47. The LOQs for these methods ranged from 0.1-0.5 microg/sample. The very low vapor pressures of both monomeric MDI and PMDI largely explain the low airborne concentrations found in most operations. However, processes or applications in which the chemical is sprayed or heated may result in higher airborne concentrations and higher exposure potentials if appropriate control measures are not implemented. Data presented in this article will be a useful reference for employers in helping them to manage their health and safety program as it relates to respiratory protection during MDI/PMDI applications.

Airborne radar radiometer measurements of tropical storms

NASA Technical Reports Server (NTRS)

Kumagai, H.; Meneghini, R.; Kozu, T.; Okamoto, K.

1992-01-01

The results from an airborne radar radiometer experiment of rainfall measurement in tropical storms are presented. The experiment was conducted in the Western Pacific in September 1990 with the NASA/DC-8 aircraft which was equipped with a nadir-loking dual-frequency rain radar operating at X band and Ka band, and several channels of microwave radiometers. The X-band radar has a capability of dual-polarization reception which enables the measurements of Linear Depolarization Ratio (LDR). The data of the microwave radiometers are compared with the radar data.

Using airborne HIAPER Pole-to-Pole Observations (HIPPO) to evaluate model and remote sensing estimates of atmospheric carbon dioxide

NASA Astrophysics Data System (ADS)

Frankenberg, Christian; Kulawik, Susan S.; Wofsy, Steven C.; Chevallier, Frédéric; Daube, Bruce; Kort, Eric A.; O'Dell, Christopher; Olsen, Edward T.; Osterman, Gregory

2016-06-01

In recent years, space-borne observations of atmospheric carbon dioxide (CO2) have been increasingly used in global carbon-cycle studies. In order to obtain added value from space-borne measurements, they have to suffice stringent accuracy and precision requirements, with the latter being less crucial as it can be reduced by just enhanced sample size. Validation of CO2 column-averaged dry air mole fractions (XCO2) heavily relies on measurements of the Total Carbon Column Observing Network (TCCON). Owing to the sparseness of the network and the requirements imposed on space-based measurements, independent additional validation is highly valuable. Here, we use observations from the High-Performance Instrumented Airborne Platform for Environmental Research (HIAPER) Pole-to-Pole Observations (HIPPO) flights from 01/2009 through 09/2011 to validate CO2 measurements from satellites (Greenhouse Gases Observing Satellite - GOSAT, Thermal Emission Sounder - TES, Atmospheric Infrared Sounder - AIRS) and atmospheric inversion models (CarbonTracker CT2013B, Monitoring Atmospheric Composition and Climate (MACC) v13r1). We find that the atmospheric models capture the XCO2 variability observed in HIPPO flights very well, with correlation coefficients (r2) of 0.93 and 0.95 for CT2013B and MACC, respectively. Some larger discrepancies can be observed in profile comparisons at higher latitudes, in particular at 300 hPa during the peaks of either carbon uptake or release. These deviations can be up to 4 ppm and hint at misrepresentation of vertical transport. Comparisons with the GOSAT satellite are of comparable quality, with an r2 of 0.85, a mean bias μ of -0.06 ppm, and a standard deviation σ of 0.45 ppm. TES exhibits an r2 of 0.75, μ of 0.34 ppm, and σ of 1.13 ppm. For AIRS, we find an r2 of 0.37, μ of 1.11 ppm, and σ of 1.46 ppm, with latitude-dependent biases. For these comparisons at least 6, 20, and 50 atmospheric soundings have been averaged for GOSAT, TES, and AIRS

Airborne lidar wind detection at 2 μm

NASA Astrophysics Data System (ADS)

Targ, Russell; Hawley, James G.; Steakley, Bruce C.; Ames, Lawrence L.; Robinson, Paul A.

1995-06-01

NASA and the FAA have expressed interest in laser radar's capabilities to detect wind profiles at altitude. A number of programs have been addressing the technical feasibility and utility of laser radar atmospheric backscatter data to determine wind profiles and wind hazards for aircraft guidance and navigation. In addition, the U.S. Air Force is investigating the use of airborne lidar to achieve precision air drop capability, and to increase the accuracy of the AC- 130 gunship and the B-52 bomber by measuring the wind field from the aircraft to the ground. There are emerging capabilities of airborne laser radar to measure wind velocities and detect turbulence and other atmospheric disturbances out in front of an aircraft in real time. The measurement of these parameters can significantly increase fuel efficiency, flight safety, airframe lifetime, and terminal area capacity for new and existing aircraft. This is achieved through wind velocity detection, turbulence avoidance, active control utilization to alleviate gust loading, and detection of wingtip wake vortices produced by landing aircraft. This paper presents the first flight test results of an all solid-state 2-micrometers laser radar system measuring the wind field profile 1 to 2 km in front of an aircraft in real time. We find 0.7-m/s wind measurement accuracy for the system which is configured in a rugged, light weight, high- performance ARINC package.

NASA Langley Atmospheric Science Data Center Toolsets for Airborne Data (TAD): Common Variable Naming Schema

NASA Astrophysics Data System (ADS)

Chen, G.; Early, A. B.; Peeters, M. C.

2014-12-01

NASA has conducted airborne tropospheric chemistry studies for about three decades. These field campaigns have generated a great wealth of observations, which are characterized by a wide range of trace gases and aerosol properties. The airborne observational data have often been used in assessment and validation of models and satellite instruments. One particular issue is a lack of consistent variable naming across field campaigns, which makes cross-mission data discovery difficult. The ASDC Toolset for Airborne Data (TAD) is being designed to meet the user community needs for manipulating aircraft data for scientific research on climate change and air quality relevant issues. As part of this effort, a common naming system was developed to provide a link between variables from different aircraft field studies. This system covers all current and past airborne in-situ measurements housed at the ASDC, as well as select NOAA missions. The TAD common variable naming system consists of 6 categories and 3 sub-levels. The top-level category is primarily defined by the physical characteristics of the measurement: e.g., aerosol, cloud, trace gases. The sub-levels were designed to organize the variables according to nature of measurement (e.g., aerosol microphysical and optical properties) or chemical structures (e.g., carbon compound). The development of the TAD common variable naming system was in consultation with staff from the Global Change Master Directory (GCMD) and referenced/expanded the existing Climate and Forecast (CF) variable naming conventions. The detailed structure of the TAD common variable naming convention and its application in TAD development will be presented.

Ultrafine particles from power plants: Evaluation of WRF-Chem simulations with airborne measurements

NASA Astrophysics Data System (ADS)

Forkel, Renate; Junkermann, Wolfgang

2017-04-01

Ultrafine particles (UFP, particles with a diameter < 100 nm) are an acknowledged risk to human health and have a potential effect on climate as their presence affects the number concentration of cloud condensation nuclei. Despite of the possibly hazardous effects no regulations exist for this size class of ambient air pollution particles. While ground based continuous measurements of UFP are performed in Germany at several sites (e.g. the German Ultrafine Aerosol Network GUAN, Birmili et al. 2016, doi:10.5194/essd-8-355-2016) information about the vertical distribution of UFP within the atmospheric boundary layer is only scarce. This gap has been closed during the last years by regional-scale airborne surveys for UFP concentrations and size distributions over Germany (Junkermann et al., 2016, doi: 10.3402/tellusb.v68.29250) and Australia (Junkermann and Hacker, 2015, doi: 10.3402/tellusb.v67.25308). Power stations and refineries have been identified as a major source of UFP in Germany with observed particle concentrations > 50000 particles cm-3 downwind of these elevated point sources. Nested WRF-Chem simulations with 2 km grid width for the innermost domain are performed with UFP emission source strengths derived from the measurements in order to study the advection and vertical exchange of UFP from power plants near the Czech and Polish border and their impact on planetary boundary layer particle patterns. The simulations are evaluated against the airborne observations and the downward mixing of the UFP from the elevated sources is studied.

Direct analysis of airborne mite allergen (Der f1) in the residential atmosphere by chemifluorescent immunoassay using bioaerosol sampler.

PubMed

Miyajima, Kumiko; Suzuki, Yurika; Miki, Daisuke; Arai, Moeka; Arakawa, Takahiro; Shimomura, Hiroji; Shiba, Kiyoko; Mitsubayashi, Kohji

2014-06-01

Dermatophagoides farinae allergen (Der f1) is one of the most important indoor allergens associated with allergic diseases in humans. Mite allergen Der f1 is usually associated with particles of high molecular weight; thus, Der f1 is generally present in settled dust. However, a small quantity of Der f1 can be aerosolized and become an airborne component. Until now, a reliable method of detecting airborne Der f1 has not been developed. The aim of this study was to develop a fiber-optic chemifluorescent immunoassay for the detection of airborne Der f1. In this method, the Der f1 concentration measured on the basis of the intensity of fluorescence amplified by an enzymatic reaction between the labeled enzyme by a detection antibody and a fluorescent substrate. The measured Der f1 concentration was in the range from 0.49 to 250 ng/ml and a similar range was found by enzyme-linked immunosorbent assay (ELISA). This method was proved to be highly sensitive to Der f1 compared with other airborne allergens. For the implementation of airborne allergen measurement in a residential environment, a bioaerosol sampler was constructed. The airborne allergen generated by a nebulizer was conveyed to a newly sampler we developed for collecting airborne Der f1. The sampler was composed of polymethyl methacrylate (PMMA) cells for gas/liquid phases and some porous membranes which were sandwiched in between the two phases. Der f1 in air was collected by the sampler and measured using the fiber-optic immunoassay system. The concentration of Der f1 in aerosolized standards was in the range from 0.125 to 2.0 mg/m(3) and the collection rate of the device was approximately 0.2%. © 2013 Elsevier B.V. All rights reserved.

Aerosol Optical Retrieval and Surface Reflectance from Airborne Remote Sensing Data over Land

PubMed Central

Bassani, Cristiana; Cavalli, Rosa Maria; Pignatti, Stefano

2010-01-01

Quantitative analysis of atmospheric optical properties and surface reflectance can be performed by applying radiative transfer theory in the Atmosphere-Earth coupled system, for the atmospheric correction of hyperspectral remote sensing data. This paper describes a new physically-based algorithm to retrieve the aerosol optical thickness at 550nm (τ550) and the surface reflectance (ρ) from airborne acquired data in the atmospheric window of the Visible and Near-Infrared (VNIR) range. The algorithm is realized in two modules. Module A retrieves τ550 with a minimization algorithm, then Module B retrieves the surface reflectance ρ for each pixel of the image. The method was tested on five remote sensing images acquired by an airborne sensor under different geometric conditions to evaluate the reliability of the method. The results, τ550 and ρ, retrieved from each image were validated with field data contemporaneously acquired by a sun-sky radiometer and a spectroradiometer, respectively. Good correlation index, r, and low root mean square deviations, RMSD, were obtained for the τ550 retrieved by Module A (r2 = 0.75, RMSD = 0.08) and the ρ retrieved by Module B (r2 ≤ 0.9, RMSD ≤ 0.003). Overall, the results are encouraging, indicating that the method is reliable for optical atmospheric studies and the atmospheric correction of airborne hyperspectral images. The method does not require additional at-ground measurements about at-ground reflectance of the reference pixel and aerosol optical thickness. PMID:22163558

MULTIPLY: Development of a European HSRL Airborne Facility

NASA Astrophysics Data System (ADS)

Binietoglou, Ioannis; Serikov, Ilya; Nicolae, Doina; Amiridis, Vassillis; Belegante, Livio; Boscornea, Andrea; Brugmann, Bjorn; Costa Suros, Montserrat; Hellmann, David; Kokkalis, Panagiotis; Linne, Holger; Stachlewska, Iwona; Vajaiac, Sorin-Nicolae

2016-08-01

MULTIPLY is a novel airborne high spectral resolution lidar (HSRL) currently under development by a consortium of European institutions from Romania, Germany, Greece, and Poland. Its aim is to contribute to calibration and validations activities of the upcoming ESA aerosol sensing missions like ADM-Aeolus, EarthCARE and the Sentinel-3/-4/-5/-5p which include products related to atmospheric aerosols. The effectiveness of these missions depends on independent airborne measurements to develop and test the retrieval methods, and validate mission products following launch. The aim of ESA's MULTIPLY project is to design, develop, and test a multi-wavelength depolarization HSRL for airborne applications. The MULTIPLY lidar will deliver the aerosol extinction and backscatter coefficient profiles at three wavelengths (355nm, 532nm, 1064nm), as well as profiles of aerosol intensive parameters (Ångström exponents, extinction- to-backscatter ratios, and linear particle depolarization ratios).

Integrated Airborne and In-Situ Measurements over Land-Fast Ice near Barrow, AK.

NASA Astrophysics Data System (ADS)

Brozena, J. M.; Gardner, J. M.; Liang, R.; Ball, D.; Richter-Menge, J.; Claffey, K. J.; Abelev, A.; Hebert, D. A.; Jones, K.

2014-12-01

During March of 2014, the Naval Research Laboratory and the Cold Regions Research and Engineering Laboratory collected an integrated set of airborne and in-situ measurements over two areas of floating, but land-fast ice near the coast of Barrow, AK. The near-shore site was just north of Point Barrow, and the "offshore" site was ~ 20 km east of Point Barrow. The in-situ data provided ground-truth for airborne measurements from a scanning LiDAR (Riegl Q 560i), digital photogrammetry (Applanix DSS-439) and a snow radar procured from the Center for Remote Sensing of Ice Sheets of the University of Kansas. The objective of the survey was to aid our understanding of the use of the airborne data to calibrate/validate Cryosat-2 data. Sampling size or "footprint" plays a critical role in the attempt to compare in-situ measurements with airborne (or satellite) measurements. Thus the in-situ data were arranged to minimize aliasing. Ground measurements were collected along transects at both sites consisting of a 2 km long profile of snow depth and ice thickness measurements with periodic boreholes. A 60 m x 400 m swath of snow depth measurements was centered on this profile. Airborne data were collected on five overflights of the two transect areas. The LiDAR measured total freeboard (ice + snow) referenced to leads in the ice, and produced swaths 200-300 m wide. The radar measured snow thickness. The freeboard and snow thickness measurements are used to estimate ice thickness via isostasy and density estimates. The central swath of in situ snow depth data allows examination of the effects of cross-track variations considering the relatively large footprint of the snow radar. Assuming a smooth, flat surface the radar range resolution in air is < 4 cm, but the along-track sampling distance is ~ 3 m after unfocussed SAR processing. The width of the footprint varies from ~ 9 m up to about 40 m (beam-limited) for uneven surfaces. However, the radar could not resolve snow thickness

All-Fiber Airborne Coherent Doppler Lidar to Measure Wind Profiles

NASA Astrophysics Data System (ADS)

Liu, Jiqiao; Zhu, Xiaopeng; Diao, Weifeng; Zhang, Xin; Liu, Yuan; Bi, Decang; Jiang, Liyuan; Shi, Wei; Zhu, Xiaolei; Chen, Weibiao

2016-06-01

An all-fiber airborne pulsed coherent Doppler lidar (CDL) prototype at 1.54μm is developed to measure wind profiles in the lower troposphere layer. The all-fiber single frequency pulsed laser is operated with pulse energy of 300μJ, pulse width of 400ns and pulse repetition rate of 10kHz. To the best of our knowledge, it is the highest pulse energy of all-fiber eye-safe single frequency laser that is used in airborne coherent wind lidar. The telescope optical diameter of monostatic lidar is 100 mm. Velocity-Azimuth-Display (VAD) scanning is implemented with 20 degrees elevation angle in 8 different azimuths. Real-time signal processing board is developed to acquire and process the heterodyne mixing signal with 10000 pulses spectra accumulated every second. Wind profiles are obtained every 20 seconds. Several experiments are implemented to evaluate the performance of the lidar. We have carried out airborne wind lidar experiments successfully, and the wind profiles are compared with aerological theodolite and ground based wind lidar. Wind speed standard error of less than 0.4m/s is shown between airborne wind lidar and balloon aerological theodolite.

Meeting Review: Airborne Aerosol Inlet Workshop

NASA Technical Reports Server (NTRS)

Baumgardner, Darrel; Huebert, Barry; Wilson, Chuck

1991-01-01

Proceedings from the Airborne Aerosol Inlet Workshop are presented. The two central topics of discussion were the role of aerosols in atmospheric processes and the difficulties in characterizing aerosols. The following topics were discussed during the working sessions: airborne observations to date; identification of inlet design issues; inlet modeling needs and directions; objectives for aircraft experiments; and future laboratory and wind tunnel studies.

Airborne Dust Cloud Measurements at the INL National Security Test Range

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michael L. Abbott; Norm Stanley; Larry Radke

2007-09-01

On July 11, 2007, a surface, high-explosive test (<20,000 lb TNT-equivalent) was carried out at the National Security Test Range (NSTR) on the Idaho National Laboratory (INL) Site. Aircraft-mounted rapid response (1-sec) particulate monitors were used to measure airborne PM-10 concentrations directly in the dust cloud and to develop a PM-10 emission factor that could be used for subsequent tests at the NSTR. The blast produced a mushroom-like dust cloud that rose approximately 2,500–3,000 ft above ground level, which quickly dissipated (within 5 miles of the source). In general, the cloud was smaller and less persistence than expected, or thatmore » might occur in other areas, likely due to the coarse sand and subsurface conditions that characterize the immediate NSTR area. Maximum short time-averaged (1-sec) PM-10 concentrations at the center of the cloud immediately after the event reached 421 µg m-3 but were rapidly reduced (by atmospheric dispersion and fallout) to near background levels (~10 µg m-3) after about 15 minutes. This occurred well within the INL Site boundary, about 8 km (5 miles) from the NSTR source. These findings demonstrate that maximum concentrations in ambient air beyond the INL Site boundary (closest is 11.2 km from NSTR) from these types of tests would be well within the 150 µg m-3 24-hour National Ambient Air Quality Standards for PM-10. Aircraft measurements and geostatistical techniques were used to successfully quantify the initial volume (1.64E+9 m3 or 1.64 km3) and mass (250 kg) of the PM-10 dust cloud, and a PM-10 emission factor (20 kg m-3 crater soil volume) was developed for this specific type of event at NSTR. The 250 kg of PM-10 mass estimated from this experiment is almost seven-times higher than the 36 kg estimated for the environmental assessment (DOE-ID 2007) using available Environmental Protection Agency (EPA 1995) emission factors. This experiment demonstrated that advanced aircraft-mounted instruments operated by

Upscaling surface energy fluxes over the North Slope of Alaska using airborne eddy-covariance measurements and environmental response functions

NASA Astrophysics Data System (ADS)

Serafimovich, Andrei; Metzger, Stefan; Hartmann, Jörg; Kohnert, Katrin; Zona, Donatella; Sachs, Torsten

2018-03-01

The objective of this study was to upscale airborne flux measurements of sensible heat and latent heat and to develop high resolution flux maps. In order to support the evaluation of coupled atmospheric/land-surface models we investigated spatial patterns of energy fluxes in relation to land-surface properties. We used airborne eddy-covariance measurements acquired by the POLAR 5 research aircraft in June-July 2012 to analyze surface fluxes. Footprint-weighted surface properties were then related to 21 529 sensible heat flux observations and 25 608 latent heat flux observations using both remote sensing and modelled data. A boosted regression tree technique was used to estimate environmental response functions between spatially and temporally resolved flux observations and corresponding biophysical and meteorological drivers. In order to improve the spatial coverage and spatial representativeness of energy fluxes we used relationships extracted across heterogeneous Arctic landscapes to infer high-resolution surface energy flux maps, thus directly upscaling the observational data. These maps of projected sensible heat and latent heat fluxes were used to assess energy partitioning in northern ecosystems and to determine the dominant energy exchange processes in permafrost areas. This allowed us to estimate energy fluxes for specific types of land cover, taking into account meteorological conditions. Airborne and modelled fluxes were then compared with measurements from an eddy-covariance tower near Atqasuk. Our results are an important contribution for the advanced, scale-dependent quantification of surface energy fluxes and provide new insights into the processes affecting these fluxes for the main vegetation types in high-latitude permafrost areas.

Sensor System Performance Evaluation and Benefits from the NPOESS Airborne Sounder Testbed-Interferometer (NAST-I)

NASA Technical Reports Server (NTRS)

Larar, A.; Zhou, D.; Smith, W.

2009-01-01

Advanced satellite sensors are tasked with improving global-scale measurements of the Earth's atmosphere, clouds, and surface to enable enhancements in weather prediction, climate monitoring, and environmental change detection. Validation of the entire measurement system is crucial to achieving this goal and thus maximizing research and operational utility of resultant data. Field campaigns employing satellite under-flights with well-calibrated FTS sensors aboard high-altitude aircraft are an essential part of this validation task. The National Polar-orbiting Operational Environmental Satellite System (NPOESS) Airborne Sounder Testbed-Interferometer (NAST-I) has been a fundamental contributor in this area by providing coincident high spectral/spatial resolution observations of infrared spectral radiances along with independently-retrieved geophysical products for comparison with like products from satellite sensors being validated. This paper focuses on some of the challenges associated with validating advanced atmospheric sounders and the benefits obtained from employing airborne interferometers such as the NAST-I. Select results from underflights of the Aqua Atmospheric InfraRed Sounder (AIRS) and the Infrared Atmospheric Sounding Interferometer (IASI) obtained during recent field campaigns will be presented.

Airborne Remote sensing of the OH tropospheric column with an Integrated Path Differential LIDAR.

NASA Astrophysics Data System (ADS)

Hanisco, T. F.; Liang, Q.; Nicely, J. M.; Brune, W. H.; Miller, D. O.; Thames, A. B.

2017-12-01

The Hydroxyl radical, OH, is central to the photochemistry that controls tropospheric oxidation including the removal of atmospheric methane. Measurements of this important species are thus critical to testing our understanding and for constraining model results. Until now, tropospheric measurements have been limited to airborne or ground-based in situ instruments best suited to test photochemical box models. However, because of the growing recognition of the importance of the global methane abundance, we have a growing need to better quantify OH at the regional to global scales that are best sampled with airborne or space-based remote sensing instruments. To address this need, we have developed an instrument concept and have begun work on a laser transmitter for an airborne integrated path differential absorption LIDAR for the detection of OH. We will describe the instrument and present the expected performance characteristics. As a demonstration, we will use measurements from the recent ATOM-1 NASA airborne campaign to show measured OH columns can be used to constrain regional and global models.

Flux Of Carbon from an Airborne Laboratory (FOCAL): Synergy of airborne and surface measures of carbon emission and isotopologue content from tundra landscape in Alaska

NASA Astrophysics Data System (ADS)

Dobosy, R.; Dumas, E.; Sayres, D. S.; Kochendorfer, J.

2013-12-01

Arctic tundra, recognized as a potential major source of new atmospheric carbon, is characterized by low topographic relief and small-scale heterogeneity consisting of small lakes and intervening tundra vegetation. This fits well the flux-fragment method (FFM) of analysis of data from low-flying aircraft. The FFM draws on 1)airborne eddy-covariance flux measurements, 2)a classified surface-characteristics map (e.g. open water vs tundra), 3)a footprint model, and 4)companion surface-based eddy-covariance flux measurements. The FOCAL, a collaboration among Harvard University's Anderson Group, NOAA's Atmospheric Turbulence and Diffusion Division (ATDD), and Aurora Flight Sciences, Inc., made coordinated flights in 2013 August with a collaborating surface site. The FOCAL gathers not only flux data for CH4 and CO2 but also the corresponding carbon-isotopologue content of these gases. The surface site provides a continuous sample of carbon flux from interstitial tundra over time throughout the period of the campaign. The FFM draws samples from the aircraft data over many instances of tundra and also open water. From this we will determine how representative the surface site is of the larger area (100 km linear scale), and how much the open water differs from the tundra as a source of carbon.

2-micron Pulsed Direct Detection IPDA Lidar for Atmospheric CO2 Measurements

NASA Astrophysics Data System (ADS)

Yu, J.; Singh, U.; Petros, M.

2012-12-01

A 2-micron high energy, pulsed Integrated Path Differential Absorption (IPDA) lidar is being developed for atmospheric CO2 measurements. Development of this lidar heavily leverages the 2-micron laser technologies developed in LaRC over the last decade. The high pulse energy, direct detection lidar operating at CO2 2-micron absorption band provides an alternate approach to measure CO2 concentrations with significant advantages. It is expected to provide high-precision measurement capability by unambiguously eliminating contamination from aerosols and clouds that can bias the IPDA measurement. Our objective is to integrate an existing high energy double-pulsed 2-micron laser transmitter with a direct detection receiver and telescope to enable an airborne capability to perform a first proof of principle demonstration of airborne direct detection CO2 measurements. The 2-micron transmitter provides 100mJ at 10Hz with double pulse format specifically designed for DIAL/IPDA instrument. The compact, rugged, highly reliable transceiver is based on unique Ho:Tm:YLF high-energy 2-micron pulsed laser technology. All the optical mounts are custom designed and have space heritage. A 16-inch diameter telescope has been designed and being manufactured for the direct detection lidar. The detector is an InGaAs Positive-Intrinsic-Negative (PIN) photodiode manufactured by Hamamatsu Corporation. The performance of the detector is characterized at various operating temperatures and bias voltages for spectral response, NEP, response time, dynamic range, and linearity. A collinear lidar structure is designed to be integrated to NASA UC12 or B200 research aircrafts. This paper will describe the design of the airborne 2-micron pulsed IPDA lidar system; the lidar operation parameters; the wavelength pair selection; laser transmitter energy, pulse rate, beam divergence, double pulse generation and accurate frequency control; detector characterization; telescope design; lidar structure design

Global monitoring of atmospheric properties by the EOS MODIS

NASA Technical Reports Server (NTRS)

King, Michael D.

1993-01-01

The Moderate Resolution Imaging Spectroradiometer (MODIS) being developed for the Earth Observing System (EOS) is well suited to the global monitoring of atmospheric properties from space. Among the atmospheric properties to be examined using MODIS observations, clouds are especially important, since they are a strong modulator of the shortwave and longwave components of the earth's radiation budget. A knowledge of cloud properties (such as optical thickness and effective radius) and their variation in space and time, which are our task objectives, is also crucial to studies of global climate change. In addition, with the use of related airborne instrumentation, such as the Cloud Absorption Radiometer (CAR) and MODIS Airborne Simulator (MAS) in intensive field experiments (both national and international campaigns, see below), various types of surface and cloud properties can be derived from the measured bidirectional reflectances. These missions have provided valuable experimental data to determine the capability of narrow bandpass channels in examining the Earth's atmosphere and to aid in defining algorithms and building an understanding of the ability of MODIS to remotely sense atmospheric conditions for assessing global change. Therefore, the primary task objective is to extend and expand our algorithm for retrieving the optical thickness and effective radius of clouds from radiation measurements to be obtained from MODIS. The secondary objective is to obtain an enhanced knowledge of surface angular and spectral properties that can be inferred from airborne directional radiance measurements.

Airborne measurements of CO2 and CH4 onboard the UK FAAM research aircraft using a, Los Gatos Research Inc, cavity enhanced absorption spectrometer

NASA Astrophysics Data System (ADS)

O'Shea, S.; Bauguitte, S.; Muller, J. B.; Le Breton, M.; Gallagher, M. W.; Allen, G.; Percival, C. J.

2012-12-01

Airborne measurements of CO2 and CH4 have been made using the UK Facility for Airborne Atmospheric Measurements (FAAM) BAe-146 research aircraft since spring 2011.The measurement system uses a commercially available analyser, based on the off-axis integrated cavity output spectroscopy technique, from Los Gatos Research Inc (FGGA, Model RMT-200). During the first year of operation (29 flights), 1 Hz measurements were found to be accurate to 0.07 ± 2.48ppbv for CH4 and -0.06± 0.66ppmv for CO2. In summer 2011, as part of the BORTAS project (Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites), outflow from boreal forest fires was measured in Eastern Canada. A number of fresh and photochemically-aged plumes were identified using simultaneous HCN measurements, a widely used tracer for biomass burning. In the freshest plumes, strong relationships were found between CH4, CO2 and other tracers for biomass burning. From this we were able to estimate that 6.9±0.8 g of CH4 and 1551±213 g of CO2 were released into the atmosphere per kg of dry matter burnt. These emission factors are in good agreement with estimates from previous studies in boreal regions. However for aged plumes the correlations between CH4 and other biomass burning tracers were not as robust, most likely due to mixing from other CH4 emission sources, such as the wetland regions. The role of additional emission sources will be investigated using the UK Met Office NAME atmospheric dispersion model and the HYSPLIT trajectory model. Using tailored back trajectory analysis, we will present an interpretation of this new dataset in the context of air mass/fire origin, relating this to MODIS fire maps and source strength.

Twenty Five Years of Airborne Observations of Ozone-Depleting and Climate-Related Gases in the Upper Troposphere and Lower Stratosphere.

NASA Astrophysics Data System (ADS)

Elkins, J. W.; Moore, F. L.; Hintsa, E. J.; Dutton, G. S.; Nance, J. D.; Hall, B. D.

2016-12-01

NOAA scientists started in situ airborne measurements of two strong ozone-depleting gases or chlorofluorocarbons, CFC-11 and CFC-113 in 1991 on the NASA ER-2 aircraft with a two-channel gas chromatograph, Airborne Chromatograph for Atmospheric Trace Species (ACATS). We broaden our list of gases to include more ozone-depleting and other climate-related gases. An improved 4-channel gas chromatograph that included N2O, SF6, CFC-11, -12, -113, halon-1211, CCl4, CH3CCl3, CH4, CO, and H2 was added to the ER-2 aircraft in 1994. As CFC replacements took hold, we add a gas chromatograph-mass spectrometer system, PAN and other Trace Hydro-halocarbon Experiment (PANTHER), to examine shorter-lived gases mainly in the upper troposphere. These airborne measurements were to complement of ground-based flask and in situ measurements from the NOAA Halocarbon and other Trace Species Network. This talk will show results from a tropical study, Airborne Tropical Tropopause Experiment (ATTREX) on the NASA Global Hawk aircraft and preliminary results from the Atmospheric Tomography Mission (ATom) conducted in August 2016 on the NASA DC-8 aircraft. A detrended, gridded, latitudinal distribution of SF6 is shown in the figure below for the years of 1994 through 2014. Such a plot may be useful to atmospheric modelers trying to capture transport or calculate emissions.

UV/visible albedos from airborne measurements

NASA Astrophysics Data System (ADS)

Webb, A.; Kylling, A.; Stromberg, I.

2003-04-01

During the INSPECTRO campaign effective surface albedo was measured at UV and visible wavelengths from two airborne platforms, a Cessna light aircraft and a hot air balloon. On board the Cessna was a scanning spectroradiometer measuring from 300 - 500nm at 10nm intervals. The NILU cube, with 6 faces and two UV channels at 312 and 340nm, was suspended beneath the hot air balloon. Flights took place over East Anglia during September, 2002. Balloon flights were made below cloud layers, while the Cessna flew both above and below cloud. The Cessna also flew over Barton Bendish, where surface albedos have been measured for ground truthing of satellite data, and measured the effective albedo at four visible wave- lengths in the centres of the satellite bandpass functions. Results of measurements from the different platforms are compared, and model simulations used to deduce the surface albedo from the effective albedo at altitude, giving, for example, an albedo of 0.02 ± 0.01 at 340nm.

How Cities Breathe: Ground-Referenced, Airborne Hyperspectral Imaging Precursor Measurements To Space-Based Monitoring

NASA Technical Reports Server (NTRS)

Leifer, Ira; Tratt, David; Quattrochi, Dale; Bovensmann, Heinrich; Gerilowski, Konstantin; Buchwitz, Michael; Burrows, John

2013-01-01

the complex and often aerosol laden, humid, urban microclimates, atmospheric transport and profile monitoring, spatial resolution, temporal cycles (diurnal and seasonal which involve interactions with the surrounding environment diurnal and seasonal cycles) and representative measurement approaches given traffic realities. Promising approaches incorporate contemporaneous airborne remote sensing and in situ measurements, nocturnal surface surveys, with ground station measurement

Development of airborne oil thickness measurements.

PubMed

Brown, Carl E; Fingas, Mervin F

2003-01-01

A laboratory sensor has now been developed to measure the absolute thickness of oil on water slicks. This prototype oil slick thickness measurement system is known as the laser-ultrasonic remote sensing of oil thickness (LURSOT) sensor. This laser opto-acoustic sensor is the initial step in the ultimate goal of providing an airborne sensor with the ability to remotely measure oil-on-water slick thickness. The LURSOT sensor employs three lasers to produce and measure the time-of-flight of ultrasonic waves in oil and hence provide a direct measurement of oil slick thickness. The successful application of this technology to the measurement of oil slick thickness will benefit the scientific community as a whole by providing information about the dynamics of oil slick spreading and the spill responder by providing a measurement of the effectiveness of spill countermeasures such as dispersant application and in situ burning. This paper will provide a review of early developments and discuss the current state-of-the-art in the field of oil slick thickness measurement.

Characterizing the solar reflection from wildfire smoke plumes using airborne multiangle measurements

NASA Astrophysics Data System (ADS)

Gatebe, C. K.; Varnai, T.; Gautam, R.; Poudyal, R.; Singh, M. K.

2016-12-01

To help better understand forest fire smoke plumes, this study examines sunlight reflected from plumes that were observed over Canada during the ARCTAS campaign in summer 2008. In particular, the study analyzes multiangle and multispectral measurements of smoke scattering by the airborne Cloud Absorption Radiometer (CAR). In combination with other in-situ and remote sensing information and radiation modeling, CAR data is used for characterizing the radiative properties and radiative impact of smoke particles—which inherently depend on smoke particle properties that influence air quality. In addition to estimating the amount of reflected and absorbed sunlight, the work includes using CAR data to create spectral and broadband top-of-atmosphere angular distribution models (ADMs) of solar radiation reflected by smoke plumes, and examining the sensitivity of such angular models to scene parameters. Overall, the results help better understand the radiative properties and radiative effects of smoke particles, and are anticipated to help better interpret satellite data on smoke plumes.

Atmospheric characterization through fused mobile airborne and surface in situ surveys: methane emissions quantification from a producing oil field

NASA Astrophysics Data System (ADS)

Leifer, Ira; Melton, Christopher; Fischer, Marc L.; Fladeland, Matthew; Frash, Jason; Gore, Warren; Iraci, Laura T.; Marrero, Josette E.; Ryoo, Ju-Mee; Tanaka, Tomoaki; Yates, Emma L.

2018-03-01

Methane (CH4) inventory uncertainties are large, requiring robust emission derivation approaches. We report on a fused airborne-surface data collection approach to derive emissions from an active oil field near Bakersfield, central California. The approach characterizes the atmosphere from the surface to above the planetary boundary layer (PBL) and combines downwind trace gas concentration anomaly (plume) above background with normal winds to derive flux. This approach does not require a well-mixed PBL; allows explicit, data-based, uncertainty evaluation; and was applied to complex topography and wind flows. In situ airborne (collected by AJAX - the Alpha Jet Atmospheric eXperiment) and mobile surface (collected by AMOG - the AutoMObile trace Gas - Surveyor) data were collected on 19 August 2015 to assess source strength. Data included an AMOG and AJAX intercomparison transect profiling from the San Joaquin Valley (SJV) floor into the Sierra Nevada (0.1-2.2 km altitude), validating a novel surface approach for atmospheric profiling by leveraging topography. The profile intercomparison found good agreement in multiple parameters for the overlapping altitude range from 500 to 1500 m for the upper 5 % of surface winds, which accounts for wind-impeding structures, i.e., terrain, trees, buildings, etc. Annualized emissions from the active oil fields were 31.3 ± 16 Gg methane and 2.4 ± 1.2 Tg carbon dioxide. Data showed the PBL was not well mixed at distances of 10-20 km downwind, highlighting the importance of the experimental design.

NASA/MSFC FY-84 Atmospheric Processes Research Review

NASA Technical Reports Server (NTRS)

Vaughan, W. W. (Compiler); Porter, F. (Compiler)

1984-01-01

The two main areas of focus for NASA/MSFC's atmospheric research program are: (1) global scale processes (geophysical fluid processes, satellite Doppler lidar wind profiler, and satellite data analyses) and (2) mesoscale processes (atmospheric electricity (lightning), ground/airborne Doppler lidar wind measurements, and mesoscale analyses and space sensors). Topics within these two general areas are addressed.

Validation of LIRIC aerosol concentration retrievals using airborne measurements during a biomass burning episode over Athens

NASA Astrophysics Data System (ADS)

Kokkalis, Panagiotis; Amiridis, Vassilis; Allan, James D.; Papayannis, Alexandros; Solomos, Stavros; Binietoglou, Ioannis; Bougiatioti, Aikaterini; Tsekeri, Alexandra; Nenes, Athanasios; Rosenberg, Philip D.; Marenco, Franco; Marinou, Eleni; Vasilescu, Jeni; Nicolae, Doina; Coe, Hugh; Bacak, Asan; Chaikovsky, Anatoli

2017-01-01

In this paper we validate the Lidar-Radiometer Inversion Code (LIRIC) retrievals of the aerosol concentration in the fine mode, using the airborne aerosol chemical composition dataset obtained over the Greater Athens Area (GAA) in Greece, during the ACEMED campaign. The study focuses on the 2nd of September 2011, when a long-range transported smoke layer was observed in the free troposphere over Greece, in the height range from 2 to 3 km. CIMEL sun-photometric measurements revealed high AOD ( 0.4 at 532 nm) and Ångström exponent values ( 1.7 at 440/870 nm), in agreement with coincident ground-based lidar observations. Airborne chemical composition measurements performed over the GAA, revealed increased CO volume concentration ( 110 ppbv), with 57% sulphate dominance in the PM1 fraction. For this case, we compare LIRIC retrievals of the aerosol concentration in the fine mode with the airborne Aerosol Mass Spectrometer (AMS) and Passive Cavity Aerosol Spectrometer Probe (PCASP) measurements. Our analysis shows that the remote sensing retrievals are in a good agreement with the measured airborne in-situ data from 2 to 4 km. The discrepancies observed between LIRIC and airborne measurements at the lower troposphere (below 2 km), could be explained by the spatial and temporal variability of the aerosol load within the area where the airborne data were averaged along with the different time windows of the retrievals.

Spectrometers for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) Upgrade to Full Sun-Sky-Cloud-Trace Gas Spectrometry Capability for Airborne Science

NASA Astrophysics Data System (ADS)

Dunagan, S. E.; Flynn, C. J.; Johnson, R. R.; Kacenelenbogen, M. S.; Knobelspiesse, K. D.; LeBlanc, S. E.; Livingston, J. M.; Redemann, J.; Russell, P. B.; Schmid, B.; Segal-Rosenhaimer, M.; Shinozuka, Y.

2014-12-01

The Spectrometers for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) instrument has been developed at NASA Ames in collaboration with Pacific Northwest National Laboratory (PNNL) and NASA Goddard, supported substantially since 2009 by NASA's Radiation Science Program and Earth Science Technology Office. It combines grating spectrometers with fiber optic links to a tracking, scanning head to enable sun tracking, sky scanning, and zenith viewing. 4STAR builds on the long and productive heritage of the NASA Ames Airborne Tracking Sunphotometers (AATS-6 and -14), which have yielded more than 100 peer-reviewed publications and extensive archived data sets in many NASA Airborne Science campaigns from 1986 to the present. The baseline 4STAR instrument has provided extensive data supporting the TCAP (Two Column Aerosol Project, July 2012 & Feb. 2013), SEAC4RS (Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys, 2013), and ARISE (Arctic Radiation - IceBridge Sea and Ice Experiment, 2014), field campaigns.This poster presents plans and progress for an upgrade to the 4STAR instrument to achieve full science capability, including (1) direct-beam sun tracking measurements to derive aerosol optical depth spectra, (2) sky radiance measurements to retrieve aerosol absorption and type (via complex refractive index and mode-resolved size distribution), (3) cloud properties via zenith radiance, and (4) trace gas spectrometry. Technical progress in context with the governing physics is reported on several upgrades directed at improved light collection and usage, particularly as related to spectrally and radiometrically stable propagation through the collection light path. In addition, improvements to field calibration and verification, and flight operability and reliability are addressed.

Airborne measurements of cloud forming nuclei and aerosol particles at Kennedy Space Center, Florida

NASA Technical Reports Server (NTRS)

Radke, L. F.; Langer, G.; Hindman, E. E., II

1978-01-01

Results of airborne measurements of the sizes and concentrations of aerosol particles, ice nuclei, and cloud condensation nuclei that were taken at Kennedy Space Center, Florida, are presented along with a detailed description of the instrumentation and measuring capabilities of the University of Washington airborne measuring facility (Douglas B-23). Airborne measurements made at Ft. Collins, Colorado, and Little Rock, Arkansas, during the ferry of the B-23 are presented. The particle concentrations differed significantly between the clean air over Ft. Collins and the hazy air over Little Rock and Kennedy Space Center. The concentrations of cloud condensation nuclei over Kennedy Space Center were typical of polluted eastern seaboard air. Three different instruments were used to measure ice nuclei: one used filters to collect the particles, and the others used optical and acoustical methods to detect ice crystals grown in portable cloud chambers. A comparison of the ice nucleus counts, which are in good agreement, is presented.

Airborne Infrared Spectroscopy of 1994 Western Wildfires

NASA Technical Reports Server (NTRS)

Worden, Helen; Beer, Reinhard; Rinsland, Curtis P.

1997-01-01

In the summer of 1994 the 0.07/ cm resolution infrared Airborne Emission Spectrometer (AES) acquired spectral data over two wildfires, one in central Oregon on August 3 and the other near San Luis Obispo, California, on August 15. The spectrometer was on board a NASA DC-8 research aircraft, flying at an altitude of 12 km. The spectra from both fires clearly show features due to water vapor, carbon dioxide, carbon monoxide, ammonia, methanol, formic acid, and ethylene at significantly higher abundance and temperature than observed in downlooking spectra of normal atmospheric and ground conditions. Column densities are derived for several species, and molar ratios are compared with previous biomass fire measurements. We believe that this is the first time such data have been acquired by airborne spectral remote sensing.

Short-term Changes of Apparent Optical Properties in a Shallow Water Environment: Observations from Repeated Airborne Hyperspectral Measurements

NASA Astrophysics Data System (ADS)

Zhang, M.; English, D. C.; Hu, C.; Carlson, P. R., Jr.; Muller-Karger, F. E.; Toro-Farmer, G.; Herwitz, S. R.

2016-02-01

An atmospheric correction algorithm has been developed for AISA imagery over optically shallow waters in Sugarloaf Key of the Florida Keys. The AISA data were collected repeatedly during several days in May 2012, October 2012, and May 2013. A non-zero near-infrared (NIR) remote sensing reflectance (Rrs) was accounted for through iterations, based on the relationship of field-measured Rrs between the NIR and red wavelengths. Validation showed mean ratios of 0.94 to 1.002 between AISA-derived and field-measured Rrs in the blue to red wavelengths, with uncertainties generally < 0.002 sr-1. Such an approach led to observations of diurnal changes of AISA-derived Rrs from repeated measurements over waters with bottom types of seagrass meadow, sand, and patch reef, which were driven by tides and/or winds depending on the bottom types. Rrs generally increased with decreasing tidal height and increasing wind speed, with more changes observed over sandy bottom than over seagrass as explained by changes in water turbidity (light attenuation) and bottom contributions. Some of these changes are larger than two times of the Rrs uncertainties from the AISA retrievals, therefore representing statistically significant changes that can be well observed from airborne measurements. The case study suggests that repeated airborne measurements may be used to study short-term changes in shallow water environments, and such a capacity may be enhanced with future geostationary satellite missions specifically designed to observe coastal ecosystems.

Novel atmospheric extinction measurement techniques for aerospace laser system applications

NASA Astrophysics Data System (ADS)

Sabatini, Roberto; Richardson, Mark

2013-01-01

Novel techniques for laser beam atmospheric extinction measurements, suitable for manned and unmanned aerospace vehicle applications, are presented in this paper. Extinction measurements are essential to support the engineering development and the operational employment of a variety of aerospace electro-optical sensor systems, allowing calculation of the range performance attainable with such systems in current and likely future applications. Such applications include ranging, weaponry, Earth remote sensing and possible planetary exploration missions performed by satellites and unmanned flight vehicles. Unlike traditional LIDAR methods, the proposed techniques are based on measurements of the laser energy (intensity and spatial distribution) incident on target surfaces of known geometric and reflective characteristics, by means of infrared detectors and/or infrared cameras calibrated for radiance. Various laser sources can be employed with wavelengths from the visible to the far infrared portions of the spectrum, allowing for data correlation and extended sensitivity. Errors affecting measurements performed using the proposed methods are discussed in the paper and algorithms are proposed that allow a direct determination of the atmospheric transmittance and spatial characteristics of the laser spot. These algorithms take into account a variety of linear and non-linear propagation effects. Finally, results are presented relative to some experimental activities performed to validate the proposed techniques. Particularly, data are presented relative to both ground and flight trials performed with laser systems operating in the near infrared (NIR) at λ = 1064 nm and λ = 1550 nm. This includes ground tests performed with 10 Hz and 20 kHz PRF NIR laser systems in a large variety of atmospheric conditions, and flight trials performed with a 10 Hz airborne NIR laser system installed on a TORNADO aircraft, flying up to altitudes of 22,000 ft.

Results of a comprehensive atmospheric aerosol-radiation experiment in the southwestern United States. I - Size distribution, extinction optical depth and vertical profiles of aerosols suspended in the atmosphere. II - Radiation flux measurements and

NASA Technical Reports Server (NTRS)

Deluisi, J. J.; Furukawa, F. M.; Gillette, D. A.; Schuster, B. G.; Charlson, R. J.; Porch, W. M.; Fegley, R. W.; Herman, B. M.; Rabinoff, R. A.; Twitty, J. T.

1976-01-01

Results are reported for a field test that was aimed at acquiring a sufficient set of measurements of aerosol properties required as input for radiative-transfer calculations relevant to the earth's radiation balance. These measurements include aerosol extinction and size distributions, vertical profiles of aerosols, and radiation fluxes. Physically consistent, vertically inhomogeneous models of the aerosol characteristics of a turbid atmosphere over a desert and an agricultural region are constructed by using direct and indirect sampling techniques. These results are applied for a theoretical interpretation of airborne radiation-flux measurements. The absorption term of the complex refractive index of aerosols is estimated, a regional variation in the refractive index is noted, and the magnitude of solar-radiation absorption by aerosols and atmospheric molecules is determined.

High-resolution measurements from the airborne Atmospheric Nitrogen Dioxide Imager (ANDI)

NASA Astrophysics Data System (ADS)

Lawrence, J. P.; Anand, J. S.; Vande Hey, J. D.; Leigh, R. R.; Monks, P. S.; Leigh, R. J.

2015-06-01

Nitrogen Dioxide is both a primary pollutant with direct health effects and a key precursor of the secondary pollutant ozone. This paper reports on the development, characterisation and test flight of the Atmospheric Nitrogen Dioxide Imager (ANDI) remote sensing system. The ANDI system includes an imaging (UV)-vis grating spectrometer able to capture scattered sunlight spectra for the determination of tropospheric nitrogen dioxide (NO2) concentrations by way of DOAS slant column density and vertical column density measurements. Results are shown for an ANDI test flight over Leicester City in the UK. Retrieved NO2 columns at a surface resolution of 80 m x 20 m revealed hot spots in a series of locations around Leicester City, including road junctions, the train station, major car parks, areas of heavy industry, a nearby airport (East Midlands) and a power station (Ratcliffe-on-Soar). In the city centre the dominant source of NO2 emissions was identified as road traffic, contributing to a background concentration as well as producing localised hot spots. Quantitative analysis revealed a significant urban increment over the city centre which increased throughout the flight.

High-resolution measurements from the airborne Atmospheric Nitrogen Dioxide Imager (ANDI)

NASA Astrophysics Data System (ADS)

Lawrence, J. P.; Anand, J. S.; Vande Hey, J. D.; White, J.; Leigh, R. R.; Monks, P. S.; Leigh, R. J.

2015-11-01

Nitrogen dioxide is both a primary pollutant with direct health effects and a key precursor of the secondary pollutant ozone. This paper reports on the development, characterisation and test flight of the Atmospheric Nitrogen Dioxide Imager (ANDI) remote sensing system. The ANDI system includes an imaging UV/Vis grating spectrometer able to capture scattered sunlight spectra for the determination of tropospheric nitrogen dioxide (NO2) concentrations by way of DOAS slant column density and vertical column density measurements. Results are shown for an ANDI test flight over Leicester City in the UK on a cloud-free winter day in February 2013. Retrieved NO2 columns gridded to a surface resolution of 80 m × 20 m revealed hotspots in a series of locations around Leicester City, including road junctions, the train station, major car parks, areas of heavy industry, a nearby airport (East Midlands) and a power station (Ratcliffe-on-Soar). In the city centre the dominant source of NO2 emissions was identified as road traffic, contributing to a background concentration as well as producing localised hotspots. Quantitative analysis revealed a significant urban increment over the city centre which increased throughout the flight.

Airborne spectral measurements of surface-atmosphere anisotropy during the SCAR-A, Kuwait oil fire, and TARFOX experiments

NASA Astrophysics Data System (ADS)

Soulen, Peter F.; King, Michael D.; Tsay, Si-Chee; Arnold, G. Thomas; Li, Jason Y.

2000-04-01

During the SCAR-A, Kuwait Oil Fire Smoke Experiment, and TARFOX deployments, angular distributions of spectral reflectance for various surfaces were measured using the scanning Cloud Absorption Radiometer (CAR) mounted on the nose of the University of Washington C-131A research aircraft. The CAR contains 13 narrowband spectral channels between 0.47 and 2.3 μm with a 190° scan aperture (5° before zenith to 5° past nadir) and 1° instantaneous field of view. The bidirectional reflectance is obtained by flying a clockwise circular orbit above the surface, resulting in a ground track approximately 3 km in diameter within about 2 min. Spectral bidirectional reflectances of four surfaces are presented: the Great Dismal Swamp in Virginia with overlying haze layer, the Saudi Arabian Desert and the Persian Gulf in the Middle East, and the Atlantic Ocean measured east of Richmond, Virginia. Although the CAR measurements are contaminated by atmospheric effects, results show distinct spectral characteristics for various types of surface-atmosphere systems, including hot spots, limb brightening and darkening, and Sun glint. In addition, the hemispherical albedo of each surface-atmosphere system is calculated directly by integrating over all high angular-resolution CAR measurements for each spectral channel. Comparing the nadir reflectance with the overall hemispherical albedo of each surface, we find that using nadir reflectances as a surrogate for hemispherical albedo can cause albedos to be underestimated by as much as 95% and overestimated by up to 160%, depending on the type of surface and solar zenith angle.

An experiment for Shuttle aerodynamic force coefficient determination from inflight dynamical and atmospheric measurements

NASA Technical Reports Server (NTRS)

Compton, H. R.; Blanchard, R. C.; Walberg, G. D.

1978-01-01

A two-phase experiment is proposed which utilizes the Shuttle Orbiter and its unique series of repeated entries into the earth's atmosphere as an airborne in situ aerodynamic testing laboratory. The objective of the experiment is to determine static aerodynamic force coefficients, first of the orbiter, and later of various entry configurations throughout the high speed flight regime, including the transition from free molecule to continuum fluid flow. The objective will be accomplished through analysis of inflight measurements from both shuttle-borne and shuttle-launched instrumented packages. Results are presented to demonstrate the feasibility of such an experiment.

Lidar Measurements of Aerosol and Ozone Distributions During the 1992 Airborne Arctic Stratospheric Expedition

NASA Technical Reports Server (NTRS)

Browell, E. V.; Butler, C. F.; Fenn, M. A.; Grant, W. B.; Carter, A. F.

1992-01-01

The LaRC airborne lidar system was operated from the ARC DC-8 aircraft during the 1992 Airborne Arctic Stratospheric Expedition (ASEE-2) to investigate the distribution of stratospheric aerosols and O3 across the Arctic vortex from Jan. to Mar. 1992. Monthly flights were made across the Arctic vortex from Anchorage, Alaska, to Stavanger, Norway, and then back to Bangor, Maine, and additional round-trip flights north into the vortex were made each month from either Stavanger or Bangor depending on the location of the vortex that month. The airborne lidar system uses the differential absorption lidar (DIAL) technique at laser wavelengths of 301.5 and 310.8 nm to measure O3 profiles above the DC-8 over the 12-25 km altitude range. Lidar measurements of aerosol backscatter and depolarization profiles over the 12-30 km altitude range are made simultaneously with the O3 measurements using infrared (IR) and visible (VIS) laser wavelengths of 603 and 1064 nm, respectively. The measurements of Pinatubo aerosols, polar stratospheric clouds, and O3 made with the airborne DIAL system during the AASE-2 expedition and to chemical and dynamical process that contribute to O3 depletion in the wintertime Arctic stratosphere.

Pluto’s Atmosphere from the 23 June 2011 Stellar Occultation: Airborne and Ground Observations

NASA Astrophysics Data System (ADS)

Person, Michael J.; Bosh, A. S.; Levine, S. E.; Gulbis, A. A. S.; Zangari, A. M.; Zuluaga, C. A.; Dunham, E. W.; Pasachoff, J. M.; Babcock, B. A.; Pandey, S.; Armhein, D.; Sallum, S.; Tholen, D. J.; Collins, P.; Bida, T.; Taylor, B.; Wolf, J.; Meyer, A.; Pfueller, E.; Wiedermann, M.; Roesser, H.; Lucas, R.; Kakkala, M.; Ciotti, J.; Plunkett, S.; Hiraoka, N.; Best, W.; Pilger, E. L.; Miceli, M.; Springmann, A.; Hicks, M.; Thackeray, B.; Emery, J.; Rapoport, S.; Ritchie, I.

2012-10-01

The double stellar occultation by Pluto and Charon of 2011 June 23 was observed from numerous ground stations as well as the Stratospheric Observatory for Infrared Astronomy (SOFIA). This first airborne occultation observation since 1995 resulted in the best occultation chords recorded for the event, in three optical wavelength bands. The data obtained from SOFIA were combined with chords obtained from the ground at the IRTF (including a full spectral light curve), the USNO--Flagstaff Station, and Leeward Community College to give a detailed profile of Pluto’s atmosphere. The data show a return to the distinct upper and lower atmospheric regions with a knee, or kink in the light curves separating them as was observed in 1988 (Millis et al. 1993), rather than the smoothly transitioning bowl-shaped light curves of recent years (Elliot et al. 2007). We analyze the upper atmosphere by fitting a model to all of the light curves obtained, resulting in a half-light radius of 1288 ± 1 km. We analyze the lower atmosphere with two different methods to provide results under the separate assumptions of particulate haze and a strong thermal gradient. Results indicate that the lower atmosphere evolves on short seasonal timescales, changing between 1988 and 2006, and then returning to approximately the 1988 state in 2011, though at significantly higher pressures. Throughout these changes, the upper atmosphere remains remarkably stable in structure, again excepting the overall pressure changes. No evidence of the onset of atmospheric collapse predicted by frost migration models is yet seen, and the atmosphere appears to be remaining at a stable pressure level. This work was supported in part by NASA Planetary Astronomy grants to MIT (NNX10AB27G) and Williams College (NNX08AO50G, NNH11ZDA001N), as well as grants from USRA (#8500-98-003) and Ames Research (#NAS2-97-01) to Lowell Observatory.

Airborne lidar measurements of the soufriere eruption of 17 april 1979.

PubMed

Fuller, W H; Sokol, S; Hunt, W H

1982-06-04

At the time of the Soufriere, St. Vincent, volcanic eruption of 17 April 1979, a NASA P-3 aircraft with an uplooking lidar (light detection and ranging) system onboard was airborne 130 kilometers east of the island. Lidar measurements of the fresh volcanic ash were made approximately 2 hours after the eruption, 120 kilometers to the northeast and east. On the evening of 18 April, the airborne lidar, on a southerly flight track, detected significant amounts of stratospheric material in layers at 16, 17, 18, and 19.5 kilometers. These data, and measurements to the north on 19 April, indicate that the volcanic plume penetrated the stratosphere to an altitude of about 20 kilometers and moved south during the first 48 hours after the eruption.

Airborne lidar measurements of the Soufriere eruption of 17 April 1979

NASA Technical Reports Server (NTRS)

Fuller, W. H., Jr.; Sokol, S.; Hunt, W. H.

1982-01-01

At the time of the Soufriere, St. Vincent, volcanic eruption of April 17, 1979, a NASA P-3 aircraft with an uplooking lidar (light detection and ranging) system onboard was airborne 130 kilometers east of the island. Lidar measurements of the fresh volcanic ash were made approximately 2 hours after the eruption, 120 kilometers to the northeast and east. On the evening of April 18, the airborne lidar, on a southerly flight track, detected significant amounts of stratospheric material in layers at 16, 17, 18, and 19.5 kilometers. These data, and measurements to the north on April 19, indicate that the volcanic plume penetrated the stratosphere to an altitude of about 20 kilometers and moved south during the first 48 hours after the eruption.

Using Atmosphere-Forest Measurements To Examine The Potential For Reduced Downwind Dose

DOE Office of Scientific and Technical Information (OSTI.GOV)

Viner, B.

2015-10-13

A 2-D dispersion model was developed to address how airborne plumes interact with the forest at Savannah River Site. Parameters describing turbulence and mixing of the atmosphere within and just above the forest were estimated using measurements of water vapor or carbon dioxide concentration made at the Aiken AmeriFlux tower for a range of stability and seasonal conditions. Stability periods when the greatest amount of mixing of an airborne plume into the forest were found for 1) very unstable environments, when atmospheric turbulence is usually at a maximum, and 2) very stable environments, when the plume concentration at the forestmore » top is at a maximum and small amounts of turbulent mixing can move a substantial portion of the plume into the forest. Plume interactions with the forest during stable periods are of particular importance because these conditions are usually considered the worst-case scenario for downwind effects from a plume. The pattern of plume mixing into the forest was similar during the year except during summer when the amount of plume mixed into the forest was nearly negligible for all but stable periods. If the model results indicating increased deposition into the forest during stable conditions can be confirmed, it would allow for a reduction in the limitations that restrict facility operations while maintaining conservative estimates for downwind effects. Continuing work is planned to confirm these results as well as estimate specific deposition velocity values for use in toolbox models used in regulatory roles.« less

Development of an Airborne Micropulse Water Vapor DIAL

NASA Astrophysics Data System (ADS)

Nehrir, A. R.; Ismail, S.

2012-12-01

Water vapor plays a key role in many atmospheric processes affecting both weather and climate. Airborne measurements of tropospheric water vapor profiles have been a longstanding observational need to not only the active remote sensing community but also to the meteorological, weather forecasting, and climate/radiation science communities. Microscale measurements of tropospheric water vapor are important for enhancing near term meteorological forecasting capabilities while mesoscale and synopticscale measurements can lead to an enhanced understanding of the complex coupled feedback mechanisms between water vapor, temperature, aerosols, and clouds. To realize tropospheric measurements of water vapor profiles over the microscale-synopticscale areas of meteorological interest, a compact and cost effective airborne micropulse differential absorption lidar (DIAL) is being investigated using newly emerging semiconductor based laser technology. Ground based micropulse DIAL (MPD) measurements of tropospheric water vapor and aerosol profiles up to 6 km and 15 km, respectively, have been previously demonstrated using an all semiconductor based laser transmitter. The DIAL transmitter utilizes a master oscillator power amplifier (MOPA) configuration where two semiconductor seed lasers are used to seed a single pass traveling wave tapered semiconductor optical amplifier (TSOA), producing up to 7μJ pulse energies over a 1 μs pulse duration at a 10 kHz pulse repetition frequency (PRF). Intercomparisons between the ground based instrument measurements and radiosonde profiles demonstrating the MPD performance under varying atmospheric conditions will be presented. Work is currently ongoing to expand upon the ground based MPD concept and to develop a compact and cost effective system capable of deployment on a mid-low altitude aircraft such as the NASA Langley B200 King Air. Initial lab experiments show that a two-three fold increase in the laser energy compared to the ground

Airborne bacteria associated with corrosion of mild steel 1010 and aluminum alloy 1100.

PubMed

Rajasekar, Aruliah; Xiao, Wang; Sethuraman, Manivannan; Parthipan, Punniyakotti; Elumalai, Punniyakotti

2017-03-01

A novel approach to measure the contribution of airborne bacteria on corrosion effects of mild steel (MS) and aluminum alloy (AA) as a function of their exposure period, and the atmospheric chemical composition was investigated at an urban industrial coastal site, Singapore. The 16S rRNA and phylogenetic analyses showed that Firmicutes are the predominant bacteria detected in AA and MS samples. The dominant bacterial groups identified were Bacillaceae, Staphylococcaceae, and Paenibacillaceae. The growth and proliferation of these bacteria could be due to the presence of humidity and chemical pollutants in the atmosphere, leading to corrosion. Weight loss showed stronger corrosion resistance of AA (1.37 mg/cm 2 ) than MS (26.13 mg/cm 2 ) over the exposure period of 150 days. The higher corrosion rate could be a result of simultaneous action of pollutants and bacterial exopolysaccharides on the metal surfaces. This study demonstrates the significant involvement of airborne bacteria on atmospheric corrosion of engineering materials.

Transmitter Pulse Estimation and Measurements for Airborne TDEM Systems

NASA Astrophysics Data System (ADS)

Vetrov, A.; Mejzr, I.

2013-12-01

The processing and interpretation of Airborne Time Domain EM data requires precise description of the transmitter parameters, including shape, amplitude and length of the transmitted pulse. There are several ways to measure pulse shape of the transmitter loop. Transmitted pulse can be recorded by a current monitor installed on the loop. The current monitor readings do not give exact image due to own time-domain physical characteristics of the current monitor. Another way is to restore the primary pulse shape from the receiver data recorded on-time, if such is possible. The receiver gives exact image of the primary field projection combined with the ground response, which can be minimized at high altitude pass, usually with a transmitter elevation higher than 1500 ft from the ground. The readings on the receiver are depending on receiver position and orientation. Modeling of airborne TDEM transmitter pulse allows us to compare estimated and measured shape of the pulse and apply required corrections. Airborne TDEM system transmitter pulse shape has been studied by authors while developing P-THEM system. The data has been gathered during in-doors and out-doors ground tests in Canada, as well as during flight tests in Canada and in India. The P-THEM system has three-axes receiver that is suspended on a tow-cable in the midpoint between the transmitter and the helicopter. The P-THEM receiver geometry does not require backing coils to dump the primary field. The system records full-wave data from the receiver and current monitor installed on the transmitter loop, including on-time and off-time data. The modeling of the transmitter pulse allowed us to define the difference between estimated and measured values. The higher accuracy pulse shape can be used for better data processing and interpretation. A developed model can be applied to similar systems and configurations.

An overview of the flight campaign for the GAUGE project: airborne greenhouse gas (and other complementary trace gas) measurements around and over the UK between April 2014 and May 2015

NASA Astrophysics Data System (ADS)

Allen, Grant; Pitt, Joseph; Le Breton, Michael; Percival, Carl; Bannan, Thomas; O'Doherty, Simon; Manning, Alistair; Rigby, Matt; Gannesan, Anita; Mead, Mohammed; Bauguitte, Stephane; Lee, James; Wenger, Angelina; Palmer, Paul

2016-04-01

This work highlights data measured during flights by the UK Facility for Airborne Atmospheric Measurement (FAAM) as part of the Greenhouse gAs UK and Global Emissions (GAUGE) campaign. A total of 17 flights (85 flight-hours) have been conducted so far around the UK mainland and Ireland to sample precision in situ CH4, CO2, N2O (and other trace gas) concentrations and meteorological parameters at altitudes up to 9500m throughout the period April 2014 to May 2015. Airborne remote sensing retrievals of greenhouse gas total columns have also been calculated using the Manchester Airborne Retrieval Scheme for the UK Met Office ARIES high resolution FTIR instrument. This airborne dataset represents a mapped climatology and a series of case studies from which to assess top-down bulk-net-flux snapshots for regions of the UK, and provides for evaluation of inverse modelling approaches that challenge bottom-up inventories, satellite remote sensing measurements, and assessment of model transport uncertainty. In this paper, we shall describe the instrumentation on the FAAM aircraft and provide a diary of GAUGE FAAM flights (and data highlights) to date; and discuss selected flights of interest to studies such as those above with a focus of net mass flux evaluation.

Cloud and Thermodynamic Parameters Retrieved from Satellite Ultraspectral Infrared Measurements

NASA Technical Reports Server (NTRS)

Zhou, Daniel K.; Smith, William L.; Larar, Allen M.; Liu, Xu; Taylor, Jonathan P.; Schluessel, Peter; Strow, L. Larrabee; Mango, Stephen A.

2008-01-01

Atmospheric-thermodynamic parameters and surface properties are basic meteorological parameters for weather forecasting. A physical geophysical parameter retrieval scheme dealing with cloudy and cloud-free radiance observed with satellite ultraspectral infrared sounders has been developed and applied to the Infrared Atmospheric Sounding Interferometer (IASI) and the Atmospheric InfraRed Sounder (AIRS). The retrieved parameters presented herein are from radiance data gathered during the Joint Airborne IASI Validation Experiment (JAIVEx). JAIVEx provided intensive aircraft observations obtained from airborne Fourier Transform Spectrometer (FTS) systems, in-situ measurements, and dedicated dropsonde and radiosonde measurements for the validation of the IASI products. Here, IASI atmospheric profile retrievals are compared with those obtained from dedicated dropsondes, radiosondes, and the airborne FTS system. The IASI examples presented here demonstrate the ability to retrieve fine-scale horizontal features with high vertical resolution from satellite ultraspectral sounder radiance spectra.

Airborne measurements in the infrared using FTIR-based imaging hyperspectral sensors

NASA Astrophysics Data System (ADS)

Puckrin, E.; Turcotte, C. S.; Lahaie, P.; Dubé, D.; Lagueux, P.; Farley, V.; Marcotte, F.; Chamberland, M.

2009-09-01

Hyperspectral ground mapping is being used in an ever-increasing extent for numerous applications in the military, geology and environmental fields. The different regions of the electromagnetic spectrum help produce information of differing nature. The visible, near-infrared and short-wave infrared radiation (400 nm to 2.5 μm) has been mostly used to analyze reflected solar light, while the mid-wave (3 to 5 μm) and long-wave (8 to 12 μm or thermal) infrared senses the self-emission of molecules directly, enabling the acquisition of data during night time. Push-broom dispersive sensors have been typically used for airborne hyperspectral mapping. However, extending the spectral range towards the mid-wave and long-wave infrared brings performance limitations due to the self emission of the sensor itself. The Fourier-transform spectrometer technology has been extensively used in the infrared spectral range due to its high transmittance as well as throughput and multiplex advantages, thereby reducing the sensor self-emission problem. Telops has developed the Hyper-Cam, a rugged and compact infrared hyperspectral imager. The Hyper-Cam is based on the Fourier-transform technology yielding high spectral resolution and enabling high accuracy radiometric calibration. It provides passive signature measurement capability, with up to 320x256 pixels at spectral resolutions of up to 0.25 cm-1. The Hyper-Cam has been used on the ground in several field campaigns, including the demonstration of standoff chemical agent detection. More recently, the Hyper-Cam has been integrated into an airplane to provide airborne measurement capabilities. A special pointing module was designed to compensate for airplane attitude and forward motion. To our knowledge, the Hyper-Cam is the first commercial airborne hyperspectral imaging sensor based on Fourier-transform infrared technology. The first airborne measurements and some preliminary performance criteria for the Hyper-Cam are presented in

Airborne measurements in the infrared using FTIR-based imaging hyperspectral sensors

NASA Astrophysics Data System (ADS)

Puckrin, E.; Turcotte, C. S.; Lahaie, P.; Dubé, D.; Farley, V.; Lagueux, P.; Marcotte, F.; Chamberland, M.

2009-05-01

Hyperspectral ground mapping is being used in an ever-increasing extent for numerous applications in the military, geology and environmental fields. The different regions of the electromagnetic spectrum help produce information of differing nature. The visible, near-infrared and short-wave infrared radiation (400 nm to 2.5 μm) has been mostly used to analyze reflected solar light, while the mid-wave (3 to 5 μm) and long-wave (8 to 12 μm or thermal) infrared senses the self-emission of molecules directly, enabling the acquisition of data during night time. Push-broom dispersive sensors have been typically used for airborne hyperspectral mapping. However, extending the spectral range towards the mid-wave and long-wave infrared brings performance limitations due to the self emission of the sensor itself. The Fourier-transform spectrometer technology has been extensively used in the infrared spectral range due to its high transmittance as well as throughput and multiplex advantages, thereby reducing the sensor self-emission problem. Telops has developed the Hyper-Cam, a rugged and compact infrared hyperspectral imager. The Hyper-Cam is based on the Fourier-transform technology yielding high spectral resolution and enabling high accuracy radiometric calibration. It provides passive signature measurement capability, with up to 320x256 pixels at spectral resolutions of up to 0.25 cm-1. The Hyper-Cam has been used on the ground in several field campaigns, including the demonstration of standoff chemical agent detection. More recently, the Hyper-Cam has been integrated into an airplane to provide airborne measurement capabilities. A special pointing module was designed to compensate for airplane attitude and forward motion. To our knowledge, the Hyper-Cam is the first commercial airborne hyperspectral imaging sensor based on Fourier-transform infrared technology. The first airborne measurements and some preliminary performance criteria for the Hyper-Cam are presented in

Visitor’s Guide to Oliktok Point Atmospheric Radiation Measurement Climate Research Facility, North Slope of Alaska

DOE Office of Scientific and Technical Information (OSTI.GOV)

Desilets, Darin; Helsel, Fred M.; Bendure, Al O.

2016-04-01

The importance of Oliktok Point, Alaska, as a focal point for climate research in the Arctic continues to grow with the addition of a U.S. Department of Energy (DOE) Atmospheric Radiation Monitoring (ARM) Climate Research Facility Mobile Facility (AMF) and the expansion of infrastructure to support airborne measurements. The site hosts a suite of instruments for making multi-year, high-fidelity atmospheric measurements; serves as a base of operations for field campaigns; and contains the only Restricted Airspace and Warning Area in the U.S. Arctic, which enables the use of unmanned aircraft systems. The use of this site by climate researchers involvesmore » several considerations, including its remoteness, harsh climate, and location amid the North Slope oilfields. This guide is intended to help visitors to Oliktok Point navigate this unique physical and administrative environment, and thereby facilitate safe and productive operations.« less

Differential absorption lidars for remote sensing of atmospheric pressure and temperature profiles

NASA Technical Reports Server (NTRS)

Korb, C. Laurence; Schwemmer, Geary K.; Famiglietti, Joseph; Walden, Harvey; Prasad, Coorg

1995-01-01

A near infrared differential absorption lidar technique is developed using atmospheric oxygen as a tracer for high resolution vertical profiles of pressure and temperature with high accuracy. Solid-state tunable lasers and high-resolution spectrum analyzers are developed to carry out ground-based and airborne measurement demonstrations and results of the measurements presented. Numerical error analysis of high-altitude airborne and spaceborne experiments is carried out, and system concepts developed for their implementation.

Implementing the ban on smoking in Israeli pubs: measuring airborne nicotine and enforcement by local authorities.

PubMed

Satran, Carmit; Drach-Zahavy, Anat; Hammond, S Katharine; Baron-Epel, Orna

2014-06-01

In 2007 an amendment to the law restricting smoking in pubs and bars (P&Bs) was enacted in Israel. However, a year after the ban only slight decreases in airborne smoke in P&Bs in one city have been reported. We aimed to assess levels of airborne nicotine in Israeli P&Bs and to measure ifself-reported enforcement of the law by local officials was associated with levels of airborne nicotine in P&Bs. Airborne nicotine levels were measured in 72 P&Bs in 29 towns in Israel; this consisted of 90% of eligible towns. In addition, 73 local authority officials were interviewed in 25 of these towns. The officials were asked to assess the local authority's level of enforcement of the law banning smoking in P&Bs. The association of levels of airborne nicotine with the levels of enforcement of the law was calculated. Data were collected during 2009-2010 and analyzed in 2010-2011. Levels of airborne nicotine were comparatively high in P&Bs. No association was detected between levels of nicotine and the P&Bs' characteristics. In the larger towns, levels of airborne nicotine were higher. In 16% of towns the local authority officials reported high levels of law enforcement. Generally, levels of reported enforcement by local authorities were low and did not predict levels of airborne nicotine in the P&Bs. Self-reported local authorities' law enforcement was not associated with levels of airborne nicotine in P&Bs in these towns. There is a need to develop ways to increase law enforcement by the local authorities or other agencies.

ARM-ACME V: ARM Airborne Carbon Measurements V on the North Slope of Alaska Field Campaign Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biraud, Sebastien C

2016-05-01

Atmospheric temperatures are warming faster in the Arctic than predicted by climate models. The impact of this warming on permafrost degradation is not well understood, but it is projected to increase carbon decomposition and greenhouse gas production (CO2 and/or CH4) by arctic ecosystems. Airborne observations of atmospheric trace gases, aerosols and cloud properties in North Slopes of Alaska (NSA) are improving our understanding of global climate, with the goal of reducing the uncertainty in global and regional climate simulations and projections. From June 1 through September 15, 2015, AAF deployed the G1 research aircraft and flew over the North Slopemore » of Alaska (38 flights, 140 science flight hours), with occasional vertical profiling over Prudhoe Bay, Oliktok point, Barrow, Atqasuk, Ivotuk, and Toolik Lake. The aircraft payload included Picarro and Los Gatos Research (LGR) analyzers for continuous measurements of CO2, CH4, H2O, and CO and N2O mixing ratios, and a 12-flask sampler for analysis of carbon cycle gases (CO2, CO, CH4, N2O, 13CO2, and trace hydrocarbon species). The aircraft payload also include measurements of aerosol properties (number size distribution, total number concentration, absorption, and scattering), cloud properties (droplet and ice size information), atmospheric thermodynamic state, and solar/infrared radiation.« less

Airborne soil organic particles generated by precipitation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Bingbing; Harder, Tristan H.; Kelly, Stephen T.

Airborne organic particles play a critical role in the Earth’s climate1, public health2, air quality3, and hydrological and carbon cycles4. These particles exist in liquid, amorphous semi-solid, or solid (glassy) phase states depending on their composition and ambient conditions5. However, sources and formation mechanisms for semi- solid and solid organic particles are poorly understood and typically neglected in atmospheric models6. Here we report field evidence for airborne solid organic particles generated by a “raindrop” mechanism7 pertinent to atmosphere – land surface interactions (Fig. 1). We find that after rain events at Southern Great Plains, Oklahoma, USA, submicron solid particles, withmore » a composition consistent with soil organic matter, contributed up to 60% of atmospheric particles in number. Subsequent experiments indicate that airborne soil organic particles are ejected from the surface of soils caused by intensive rains or irrigation. Our observations suggest that formation of these particles may be a widespread phenomenon in ecosystems where soils are exposed to strong, episodic precipitation events such as agricultural systems and grasslands8. Chemical imaging and micro-spectroscopy analysis of their physico-chemical properties suggests that airborne soil organic particles may have important impacts on cloud formation and efficiently absorb solar radiation and hence, are an important type of particles.« less

Airborne derivation of microburst alerts from ground-based Terminal Doppler Weather Radar information: A flight evaluation

NASA Technical Reports Server (NTRS)

Hinton, David A.

1993-01-01

An element of the NASA/FAA windshear program is the integration of ground-based microburst information on the flight deck, to support airborne windshear alerting and microburst avoidance. NASA conducted a windshear flight test program in the summer of 1991 during which airborne processing of Terminal Doppler Weather Radar (TDWR) data was used to derive microburst alerts. Microburst information was extracted from TDWR, transmitted to a NASA Boeing 737 in flight via data link, and processed to estimate the windshear hazard level (F-factor) that would be experienced by the aircraft in each microburst. The microburst location and F-factor were used to derive a situation display and alerts. The situation display was successfully used to maneuver the aircraft for microburst penetrations, during which atmospheric 'truth' measurements were made. A total of 19 penetrations were made of TDWR-reported microburst locations, resulting in 18 airborne microburst alerts from the TDWR data and two microburst alerts from the airborne reactive windshear detection system. The primary factors affecting alerting performance were spatial offset of the flight path from the region of strongest shear, differences in TDWR measurement altitude and airplane penetration altitude, and variations in microburst outflow profiles. Predicted and measured F-factors agreed well in penetrations near microburst cores. Although improvements in airborne and ground processing of the TDWR measurements would be required to support an airborne executive-level alerting protocol, the practicality of airborne utilization of TDWR data link data has been demonstrated.

Ground and Airborne Methane Measurements using Optical Parametric Amplifiers

NASA Technical Reports Server (NTRS)

Riris, Haris; Numata, Kenji; Li, Steve; Wu, Stewart; Kawa, Stephan R.; Abshire, James; Dawsey, Martha; Ramanathan, Anand

2012-01-01

We report on an initial airborne demonstration of atmospheric methane column measurements at 1.65 micrometers using a widely tunable, seeded optical parametric amplifier (OPA) lidar and a photon counting detector. Methane is an important greenhouse gas and accurate knowledge of its sources and sinks is needed for climate modeling. Our lidar system uses 20 pulses at increasing wavelengths and integrated path differential absorption (IPDA) to map a methane line at 1650.9 nanometers. The wavelengths are generated by using a Nd:YAG pump laser at 1064.5 nanometers and distributed feedback diode laser at 1650.9 nanometers and a periodically-poled lithium niobate (PPLN) crystal. The pulse width was 3 nanoseconds and the pulse repetition rate was 6.28 KHz. The outgoing energy was approximately 13 microJoules/pulse. A commercial 20 nanometer diameter fiber-coupled telescope with a photon counting detector operated in analog mode with a 0.8 nanometer bandpass filter was used as the lidar receiver. The lidar system was integrated on NASA's DC-8 flying laboratory, based at Dryden Airborne operations Facility (DAOF) in Palmdale CA. Three flights were performed in the central valley of California. Each flight lasted about 2.5 hours and it consisted of several flight segments at constant altitudes at approximately 3, 4.5, 6, 7.6, 9.1, 10.6 km (l0, 15, 20, 25, 30, 35 kft). An in-situ cavity ring down spectrometer made by Picarro Inc. was flown along with the lidar instrument provided us with the "truth" i.e. the local CH4, CO2 and H2O concentrations at the constant flight altitude segments. Using the aircraft's altitude, GPS, and meteorological data we calculated the theoretical differential optical depth of the methane absorption at increasing altitudes. Our results showed good agreement between the experimentally derived optical depth measurements from the lidar instrument and theoretical calculations as the flight altitude was increased from 3 to 10.6 kilometers, assuming a

Vertical profiles of urban aerosol complex refractive index in the frame of ESQUIF airborne measurements

NASA Astrophysics Data System (ADS)

Raut, J.-C.; Chazette, P.

2007-07-01

A synergy between lidar, sunphotometer and in situ measurements has been applied to airborne observations performed during the Etude et Simulation de la QUalité de l'air en Ile-de-France (ESQUIF), enabling the retrieval of vertical profiles for the aerosol complex refractive index (ACRI) and single-scattering albedo with a vertical resolution of 200 m over Paris area. The averaged value over the entire planetary boundary layer (PBL) for the ACRI is close to 1.51(±0.02)-i0.017(±0.003) at 532 nm. The single-scattering albedo of the corresponding aerosols is found to be ~0.9 at the same wavelength. A good agreement is found with previous studies for urban aerosols. A comparison of vertical profiles of ACRI with simulations combining in situ measurements and relative humidity (RH) profiles has highlighted a modification in aerosol optical properties linked to their history and the origin of the air mass. The determination of ACRI in the atmospheric column enabled to retrieve vertical profiles of extinction coefficient in accordance with lidar profiles measurements.

Vertical profiles of urban aerosol complex refractive index in the frame of ESQUIF airborne measurements

NASA Astrophysics Data System (ADS)

Raut, J.-C.; Chazette, P.

2008-02-01

A synergy between lidar, sunphotometer and in situ measurements has been applied to airborne observations performed during the Etude et Simulation de la QUalité de l'air en Ile-de-France (ESQUIF), enabling the retrieval of vertical profiles for the aerosol complex refractive index (ACRI) and single-scattering albedo with a vertical resolution of 200 m over Paris area. The averaged value over the entire planetary boundary layer (PBL) for the ACRI is close to 1.51(±0.02)-i0.017(±0.003) at 532 nm. The single-scattering albedo of the corresponding aerosols is found to be ~0.9 at the same wavelength. A good agreement is found with previous studies for urban aerosols. A comparison of vertical profiles of ACRI with simulations combining in situ measurements and relative humidity (RH) profiles has highlighted a modification in aerosol optical properties linked to their history and the origin of the air mass. The determination of ACRI in the atmospheric column enabled to retrieve vertical profiles of extinction coefficient in accordance with lidar profiles measurements.

Atmospheric and surface temperatures and airborne dust amounts during late southern summer from Mariner 9 IRIS data

NASA Technical Reports Server (NTRS)

Santee, M.; Crisp, D.

1992-01-01

The temperature structure and dust loading of the Martian atmosphere are investigated using thermal emission spectra recorded in 1972 by the Mariner 9 infrared interferometer spectrometer (IRIS). The analysis focuses on a subset of data consisting of approximately 2400 spectra obtained near the end of the southern summer season (L(sub s) equal to 343 deg to 348 deg), after the global dust storm had largely abated and airborne dust amounts were subsiding to background values. Simultaneous retrieval of the vertical distribution of both atmospheric temperature and dust optical depth is accomplished through an iterative procedure which is performed on each individual spectrum. The atmospheric transmittances are calculated using a Voigt quasi-random band model, which includes absorption by CO2 and dust, but neglects the effects of multiple scattering. Vertical profiles of temperature and dust optical depth are obtained using modified algorithms. These profiles are used to construct global maps of temperature and dust optical depth as functions of latitude (+/- 90 deg), altitude (approximately 0-50 km), and local time of day.

Ultrasonic airborne insertion loss measurements at normal incidence (L).

PubMed

Farley, Jayrin; Anderson, Brian E

2010-12-01

Transmission loss and insertion loss measurements of building materials at audible frequencies are commonly made using plane wave tubes or as a panel between reverberant rooms. These measurements provide information for noise isolation control in architectural acoustics and in product development. Airborne ultrasonic sound transmission through common building materials has not been fully explored. Technologies and products that utilize ultrasonic frequencies are becoming increasingly more common, hence the need to conduct such measurements. This letter presents preliminary measurements of the ultrasonic insertion loss levels for common building materials over a frequency range of 28-90 kHz using continuous-wave excitation.

Simple method for measuring vibration amplitude of high power airborne ultrasonic transducer: using thermo-couple.

PubMed

Saffar, Saber; Abdullah, Amir

2014-03-01

Vibration amplitude of transducer's elements is the influential parameters in the performance of high power airborne ultrasonic transducers to control the optimum vibration without material yielding. The vibration amplitude of elements of provided high power airborne transducer was determined by measuring temperature of the provided high power airborne transducer transducer's elements. The results showed that simple thermocouples can be used both to measure the vibration amplitude of transducer's element and an indicator to power transmission to the air. To verify our approach, the power transmission to the air has been investigated by other common method experimentally. The experimental results displayed good agreement with presented approach. Copyright © 2013 Elsevier B.V. All rights reserved.

OPTIMIZING THE PAKS METHOD FOR MEASURING AIRBORNE ACROLEIN

EPA Science Inventory

Airborne acrolein is produced from the combustion of fuel and tobacco and is of concern due to its potential for respiratory tract irritation and other adverse health effects. Active sampling with DNPH-coated solid sorbents has been widely used for sampling airborne carbonyls; ...

OPTIMIZING THE PAKS METHOD FOR MEASURING AIRBORNE ACROLEIN

EPA Science Inventory

Airborne acrolein is produced from the combustion of fuel and tobacco and is of concern due to its potential for respiratory tract irritation and other adverse health effects. DNPH active-sampling is a method widely used for sampling airborne aldehydes and ketones (carbonyls); ...

Sampling and analysis method for measuring airborne coal dust mass in mixtures with limestone (rock) dust.

PubMed

Barone, T L; Patts, J R; Janisko, S J; Colinet, J F; Patts, L D; Beck, T W; Mischler, S E

2016-01-01

Airborne coal dust mass measurements in underground bituminous coal mines can be challenged by the presence of airborne limestone dust, which is an incombustible dust applied to prevent the propagation of dust explosions. To accurately measure the coal portion of this mixed airborne dust, the National Institute for Occupational Safety and Health (NIOSH) developed a sampling and analysis protocol that used a stainless steel cassette adapted with an isokinetic inlet and the low temperature ashing (LTA) analytical method. The Mine Safety and Health Administration (MSHA) routinely utilizes this LTA method to quantify the incombustible content of bulk dust samples collected from the roof, floor, and ribs of mining entries. The use of the stainless steel cassette with isokinetic inlet allowed NIOSH to adopt the LTA method for the analysis of airborne dust samples. Mixtures of known coal and limestone dust masses were prepared in the laboratory, loaded into the stainless steel cassettes, and analyzed to assess the accuracy of this method. Coal dust mass measurements differed from predicted values by an average of 0.5%, 0.2%, and 0.1% for samples containing 20%, 91%, and 95% limestone dust, respectively. The ability of this method to accurately quantify the laboratory samples confirmed the validity of this method and allowed NIOSH to successfully measure the coal fraction of airborne dust samples collected in an underground coal mine.

Sampling and analysis method for measuring airborne coal dust mass in mixtures with limestone (rock) dust

PubMed Central

Barone, T. L.; Patts, J. R.; Janisko, S. J.; Colinet, J. F.; Patts, L. D.; Beck, T. W.; Mischler, S. E.

2016-01-01

Airborne coal dust mass measurements in underground bituminous coal mines can be challenged by the presence of airborne limestone dust, which is an incombustible dust applied to prevent the propagation of dust explosions. To accurately measure the coal portion of this mixed airborne dust, the National Institute for Occupational Safety and Health (NIOSH) developed a sampling and analysis protocol that used a stainless steel cassette adapted with an isokinetic inlet and the low temperature ashing (LTA) analytical method. The Mine Safety and Health Administration (MSHA) routinely utilizes this LTA method to quantify the incombustible content of bulk dust samples collected from the roof, floor, and ribs of mining entries. The use of the stainless steel cassette with isokinetic inlet allowed NIOSH to adopt the LTA method for the analysis of airborne dust samples. Mixtures of known coal and limestone dust masses were prepared in the laboratory, loaded into the stainless steel cassettes, and analyzed to assess the accuracy of this method. Coal dust mass measurements differed from predicted values by an average of 0.5%, 0.2%, and 0.1% for samples containing 20%, 91%, and 95% limestone dust, respectively. The ability of this method to accurately quantify the laboratory samples confirmed the validity of this method and allowed NIOSH to successfully measure the coal fraction of airborne dust samples collected in an underground coal mine. PMID:26618374

Measuring fire spread rates from repeat pass airborne thermal infrared imagery

Treesearch

Douglas A. Stow; Philip J. Riggan; Emanual A. Storey; Lloyd L. Coulter

2014-01-01

The objective is to evaluate procedures for direct measurement of fire spread rates (FSRs) based on archived repeat pass airborne thermal infrared (ATIR) imagery and to identify requirements for more refined measurements of FSR and environmental factors that influence FSR. Flaming front positions are delineated on sequential FireMapper ATIR images captured at...

Measurement of In-Flight Aircraft Emissions

NASA Technical Reports Server (NTRS)

Sokoloski, M.; Arnold, C.; Rider, D.; Beer, R.; Worden, H.; Glavich, T.

1995-01-01

Aircraft engine emission and their chemical and physical evolution can be measured in flight using high resolution infrared spectroscopy. The Airborne Emission Spectrometer (AES), designed for remote measure- ments of atmosphere emissions from an airborne platform, is an ideal tool for the evaluation of aircraft emissions and their evolution. Capabilities of AES will be discussed. Ground data will be given.

Investigating Ozone Sources in California Using AJAX Airborne Measurements and Models: Implications for Stratospheric Intrusion and Long Range Transport

NASA Technical Reports Server (NTRS)

Ryoo, Ju-Mee; Johnson, Matthew S.; Iraci, Laura T.; Yates, Emma L.; Pierce, R. Bradley; Tanaka, Tomoaki; Gore, Warren

2016-01-01

High ozone concentrations at low altitudes near the surface were detected from airborne Alpha Jet Atmospheric eXperiment (AJAX) measurements on May 30, 2012. We investigate the causes of the elevated ozone concentrations using the airborne measurements and various models. GEOSchem and WRF-STILT model simulations show that the contribution from local sources is small. From MERRA reanalysis, it is found that high potential vorticity (PV) is observed at low altitudes. This high PV appears to be only partially coming through the stratospheric intrusions because the air inside the high PV region is moist, which shows that mixing appears to be enhanced in the low altitudes. Considering that diabatic heating can also produce high PV in the lower troposphere, high ozone is partially coming through stratospheric intrusion, but this cannot explain the whole ozone concentration in the target areas of the western U.S. A back-trajectory model is utilized to see where the air masses originated. The air masses of the target areas came from the lower stratosphere (LS), upper (UT), mid- (MT), and lower troposphere (LT). The relative number of trajectories coming from LS and UT is low (7.7% and 7.6%, respectively) compared to that from LT (64.1%), but the relative ozone concentration coming from LS and UT is high (38.4% and 20.95%, respectively) compared to that from LT (17.7%). The air mass coming from LT appears to be mostly coming from Asia. Q diagnostics show that there is sufficient mixing along the trajectory to indicate that ozone from the different origins is mixed and transported to the western U.S. This study shows that high ozone concentrations can be detected by airborne measurements, which can be analyzed by integrated platforms such as models, reanalysis, and satellite data.

Atmospheric radiation measurement unmanned aerospace vehicle (ARM-UAV) program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bolton, W.R.

1996-11-01

ARM-UAV is part of the multi-agency U.S. Global Change Research Program and is addressing the largest source of uncertainty in predicting climatic response: the interaction of clouds and the sun`s energy in the Earth`s atmosphere. An important aspect of the program is the use of unmanned aerospace vehicles (UAVs) as the primary airborne platform. The ARM-UAV Program has completed two major flight series: The first series conducted in April, 1994, using an existing UAV (the General Atomics Gnat 750) consisted of eight highly successful flights at the DOE climate site in Oklahoma. The second series conducted in September/October, 1995, usingmore » two piloted aircraft (Egrett and Twin Otter), featured simultaneous measurements above and below clouds and in clear sky. Additional flight series are planned to continue study of the cloudy and clear sky energy budget in the Spring and Fall of 1996 over the DOE climate site in Oklahoma. 3 refs., 4 figs., 1 tab.« less

Regional and Global Atmospheric CO2 Measurements Using 1.57 Micron IM-CW Lidar

NASA Technical Reports Server (NTRS)

Lin, Bing; Obland, Michael; Nehrir, Amin; Browell, Edward; Harrison, F. Wallace; Dobler, Jeremy; Campbell, Joel; Kooi, Susan; Meadows, Byron; Fan, Tai-Fang;

CARVE Measurements of Atmospheric Methane Concentrations and Emissions in Arctic and Boreal Alaska

NASA Astrophysics Data System (ADS)

Miller, C. E.; Miller, J. B.; Chang, R. Y.; Sweeney, C.; Karion, A.; Wofsy, S. C.; Henderson, J.; Eluszkiewicz, J.; Mountain, M.; Oechel, W. C.

2013-12-01

The Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) is a NASA Earth Ventures (EV-1) investigation designed to quantify correlations between atmospheric and surface state variables for the Alaskan terrestrial ecosystems through intensive seasonal aircraft campaigns, ground-based observations, and analysis sustained over a 5-year mission. CARVE bridges critical gaps in our knowledge and understanding of Arctic ecosystems, linkages between the Arctic hydrologic and terrestrial carbon cycles, and the feedbacks from fires and thawing permafrost. We present CARVE airborne measurements of spatial and temporal patterns in atmospheric CH4 concentrations and estimated surface-atmosphere emissions for Arctic and Boreal Alaska. Continuous in situ CH4, CO2 and CO data are supplemented by periodic whole air flask samples from which 13CH4 and non-methane hydrocarbons are used to assess the relative contributions of wetlands, fossil fuel combustion, and oil and gas production to the observed CH4 signals. The CARVE project has also initiated monthly 14CH4 sampling at Barrow, AK (BRW) and the CARVE Tower in Fox, AK (CRV) to evaluate seasonal changes in the fraction of old carbon being mobilized via methanogenesis.

Airborne tracking sunphotometer

NASA Technical Reports Server (NTRS)

Matsumoto, Tak; Russell, Philip; Mina, Cesar; Van Ark, William; Banta, Victor

1987-01-01

An airborne tracking sunphotometer, mounted on the outside top surface of an aircaft has been developed to provide unresricted viewing of the sun. This instrument will substantially increase the data that scientists can gather for atmospheric studies. The instrument has six wavelength channels and an automatic data gathering system. The instrument's optical features, tracking capability, mechanical features, and data gathering system are described.

Atmospheric Pollution from Shipping and Oil platforms of West Africa (APSOWA) observed during the airborne DACCIWA campaign

NASA Astrophysics Data System (ADS)

Krysztofiak-Tong, Gisèle; Brocchi, Vanessa; Catoire, Valéry; Stratmann, Greta; Sauer, Daniel; Deroubaix, Adrien; Deetz, Konrad; Schlager, Hans

2017-04-01

In the framework of the European DACCIWA (Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa) project, the airborne study APSOWA (Atmospheric Pollution from Shipping and Oil platforms of West Africa) has been conducted in July 2016 to study emissions from oil rigs and maritime traffic in the Gulf of Guinea. The measurements were performed during four flights of about 3-4 hours including meandering transects through emission plumes in the planetary boundary layer (around 300 m asl) off the coast of West Africa from Ivory Coast to Togo. Several instruments have been used on-board the DLR Falcon-20, providing measurements of the pollutants O3, CO, NO2, SO2, aerosol content and meteorological parameters. This set of trace gases can be used to fingerprint different sources of local air pollution. The first part of our study is focused on the FPSO Kwame Nkrumah facility operating in the Jubilee oil field off the coast of Ghana. Aircraft observations have been combined with a nested-grid regional scale Lagrangian particle dispersion model (FLEXPART) to estimate surface emission fluxes from this platform. A simplified inverse method is used and repeated until the modelling output and aircraft observations converged. The estimated fluxes of CO, SO2, NO2 are compared to global (EDGAR, MACCity) and regional (Deetz and Vogel, 2017, in press) inventories. A second part of the study provides the first results of the APSOWA flights for the study of the impact of shipping emissions on the regional air quality. Using data from Marine Traffic, ship positions during the campaign are identified. Then, FLEXPART is used to quantify the contributions of the ship emissions to the aircraft observations. Finally, direct measurements in the MBL around 4°N latitude along the Ghana coast show no strong evidence of the presence of an atmospheric pollution maritime corridor simulated by MACCity.

An Algorithm to Atmospherically Correct Visible and Thermal Airborne Imagery

NASA Technical Reports Server (NTRS)

Rickman, Doug L.; Luvall, Jeffrey C.; Schiller, Stephen; Arnold, James E. (Technical Monitor)

2000-01-01

The program Watts implements a system of physically based models developed by the authors, described elsewhere, for the removal of atmospheric effects in multispectral imagery. The band range we treat covers the visible, near IR and the thermal IR. Input to the program begins with atmospheric pal red models specifying transmittance and path radiance. The system also requires the sensor's spectral response curves and knowledge of the scanner's geometric definition. Radiometric characterization of the sensor during data acquisition is also necessary. While the authors contend that active calibration is critical for serious analytical efforts, we recognize that most remote sensing systems, either airborne or space borne, do not as yet attain that minimal level of sophistication. Therefore, Watts will also use semi-active calibration where necessary and available. All of the input is then reduced to common terms, in terms of the physical units. From this it Is then practical to convert raw sensor readings into geophysically meaningful units. There are a large number of intricate details necessary to bring an algorithm or this type to fruition and to even use the program. Further, at this stage of development the authors are uncertain as to the optimal presentation or minimal analytical techniques which users of this type of software must have. Therefore, Watts permits users to break out and analyze the input in various ways. Implemented in REXX under OS/2 the program is designed with attention to the probability that it will be ported to other systems and other languages. Further, as it is in REXX, it is relatively simple for anyone that is literate in any computer language to open the code and modify to meet their needs. The authors have employed Watts in their research addressing precision agriculture and urban heat island.

The wildfire experiment (WIFE): observations with airborne remote sensors

Treesearch

L.F. Radke; T.L. Clark; J.L. Coen; C.A. Walther; R.N. Lockwood; P.J. Riggan; J.A. Brass; R.G. Higgins

2000-01-01

Airborne remote sensors have long been a cornerstone of wildland fire research, and recently three-dimensional fire behaviour models fully coupled to the atmosphere have begun to show a convincing level of verisimilitude. The WildFire Experiment (WiFE) attempted the marriage of airborne remote sensors, multi-sensor observations together with fire model development and...

Airborne tests of an OAWL Doppler lidar: Results and potential for space deployment

NASA Astrophysics Data System (ADS)

Hardesty, Michael; Tucker, Sara; Baidar, Sunil; Beubien, Mark

2018-04-01

The 532 nm Green Optical Covariance Wind Lidar (GrOAWL) was flown on a NASA WB-57 research aircraft during the summer of 2016 to validate the instrument design and evaluate wind measurement capability and sensitivity. Comparisons with dropsondes and atmospheric models showed good agreement, demonstrating that a GrOAWL type instrument could provide high-value wind measurements from both airborne and space-based platforms

Convenient models of the atmosphere: optics and solar radiation

NASA Astrophysics Data System (ADS)

Alexander, Ginsburg; Victor, Frolkis; Irina, Melnikova; Sergey, Novikov; Dmitriy, Samulenkov; Maxim, Sapunov

2017-11-01

Simple optical models of clear and cloudy atmosphere are proposed. Four versions of atmospheric aerosols content are considered: a complete lack of aerosols in the atmosphere, low background concentration (500 cm-3), high concentrations (2000 cm-3) and very high content of particles (5000 cm-3). In a cloud scenario, the model of external mixture is assumed. The values of optical thickness and single scattering albedo for 13 wavelengths are calculated in the short wavelength range of 0.28-0.90 µm, with regard to the molecular absorption bands, that is simulated with triangle function. A comparison of the proposed optical parameters with results of various measurements and retrieval (lidar measurement, sampling, processing radiation measurements) is presented. For a cloudy atmosphere models of single-layer and two-layer atmosphere are proposed. It is found that cloud optical parameters with assuming the "external mixture" agrees with retrieved values from airborne observations. The results of calculating hemispherical fluxes of the reflected and transmitted solar radiation and the radiative divergence are obtained with the Delta-Eddington approach. The calculation is done for surface albedo values of 0, 0.5, 0.9 and for spectral values of the sandy surface. Four values of solar zenith angle: 0°, 30°, 40° and 60° are taken. The obtained values are compared with data of radiative airborne observations. Estimating the local instantaneous radiative forcing of atmospheric aerosols and clouds for considered models is presented together with the heating rate.

International Symposium on Airborne Geophysics

NASA Astrophysics Data System (ADS)

Mogi, Toru; Ito, Hisatoshi; Kaieda, Hideshi; Kusunoki, Kenichiro; Saltus, Richard W.; Fitterman, David V.; Okuma, Shigeo; Nakatsuka, Tadashi

2006-05-01

Airborne geophysics can be defined as the measurement of Earth properties from sensors in the sky. The airborne measurement platform is usually a traditional fixed-wing airplane or helicopter, but could also include lighter-than-air craft, unmanned drones, or other specialty craft. The earliest history of airborne geophysics includes kite and hot-air balloon experiments. However, modern airborne geophysics dates from the mid-1940s when military submarine-hunting magnetometers were first used to map variations in the Earth's magnetic field. The current gamut of airborne geophysical techniques spans a broad range, including potential fields (both gravity and magnetics), electromagnetics (EM), radiometrics, spectral imaging, and thermal imaging.

Overview of Lidar Contributions to the Atmospheric Carbon and Transport - America (ACT-America) Program

NASA Astrophysics Data System (ADS)

Davis, K. J.; Meadows, B.; Barrick, J. D. W.; Bell, E.; Browell, E. V.; Campbell, J. F.; DiGangi, J. P.; Chen, G.; Dobler, J. T.; Fan, T. F.; Feng, S.; Fried, A.; Kooi, S. A.; Lauvaux, T.; Lin, B.; McGill, M. J.; Miles, N.; Nehrir, A. R.; Obland, M. D.; O'Dell, C.; Pal, S.; Pauly, R.; Sweeney, C.; Yang, M. Y.

2017-12-01

The Atmospheric Carbon and Transport - America (ACT-America) is an Earth Venture Suborbital -2 (EVS-2) mission sponsored by the Earth Science Division of NASA's Science Mission Directorate. A major objective is to enhance our knowledge of the sources/sinks and transport of atmospheric CO2 through the application of remote and in situ airborne measurements of CO2 and other atmospheric properties on spatial and temporal scales not previously available to the science community. ACT-America consists of five campaigns to measure regional carbon and evaluate transport under various meteorological conditions in three regional areas of the Continental United States. Three of the five campaigns, summer 2016, winter 2017, and fall 2017, have taken place. Data have been collected during these campaigns using 2 airborne platforms (NASA Wallops' C-130 and NASA Langley's B-200) with in-situ instruments on both aircraft and three lidar systems on the C-130, along with instrumented towers and coordinated under flights with the Orbiting Carbon Observatory (OCO-2) satellite. The lidar systems include the Harris Corp. Multi-Frequency Fiber Laser Lidar (MFLL), the NASA Langley ASCENDS CarbonHawk Experiment Simulator (ACES) and the Goddard Cloud Physics Laboratory (CPL). The airborne lidars provide unique data that complement the more traditional in situ sensors. Lidar CO2 measurements provide integrated views of spatial variations of partial columns of atmospheric CO2 which can be adjusted to the column of scientific interest by changing flight altitudes. Lidar backscatter data provide detailed views of atmospheric layers, including the atmospheric boundary layer, residual layers, and cloud layers. The combination of these two lidars provide a far more comprehensive view of atmospheric structure and CO2 content than can be achieved with in situ measurements alone. This presentation provides an overview of the application of these three lidar systems toward achieving ACT

Measurements of Ultra-fine and Fine Aerosol Particles over Siberia: Large-scale Airborne Campaigns

NASA Astrophysics Data System (ADS)

Arshinov, Mikhail; Paris, Jean-Daniel; Stohl, Andreas; Belan, Boris; Ciais, Philippe; Nédélec, Philippe

2010-05-01

In this paper we discuss the results of in-situ measurements of ultra-fine and fine aerosol particles carried out in the troposphere from 500 to 7000 m in the framework of several International and Russian State Projects. Number concentrations of ultra-fine and fine aerosol particles measured during intensive airborne campaigns are presented. Measurements carried over a great part of Siberia were focused on particles with diameters from 3 to 21 nm to study new particle formation in the free/upper troposphere over middle and high latitudes of Asia, which is the most unexplored region of the Northern Hemisphere. Joint International airborne surveys were performed along the following routes: Novosibirsk-Salekhard-Khatanga-Chokurdakh-Pevek-Yakutsk-Mirny-Novosibirsk (YAK-AEROSIB/PLARCAT2008 Project) and Novosibirsk-Mirny-Yakutsk-Lensk-Bratsk-Novosibirsk (YAK-AEROSIB Project). The flights over Lake Baikal was conducted under Russian State contract. Concentrations of ultra-fine and fine particles were measured with automated diffusion battery (ADB, designed by ICKC SB RAS, Novosibirsk, Russia) modified for airborne applications. The airborne ADB coupled with CPC has an additional aspiration unit to compensate ambient pressure and changing flow rate. It enabled to classify nanoparticles in three size ranges: 3-6 nm, 6-21 nm, and 21-200 nm. To identify new particle formation events we used similar specific criteria as Young et al. (2007): (1) N3-6nm >10 cm-3, (2) R1=N3-6/N621 >1 and R2=N321/N21200 >0.5. So when one of the ratios R1 or R2 tends to decrease to the above limits the new particle formation is weakened. It is very important to notice that space scale where new particle formation was observed is rather large. All the events revealed in the FT occurred under clean air conditions (low CO mixing ratios). Measurements carried out in the atmospheric boundary layer over Baikal Lake did not reveal any event of new particle formation. Concentrations of ultra

Characterization of Fine Airborne Particulate Collected in Tokyo and Major Atmospheric Emission Sources by Using Single Particle Measurement of SEM-EDX

NASA Astrophysics Data System (ADS)

Sato, K.; Iijima, A.; Furuta, N.

2008-12-01

In our long-term monitoring of size-classified Airborne Particulate Matter (APM) in Tokyo since 1995, it had been demonstrated that toxic elements such as As, Se, Cd, Sb and Pb were extremely enriched in fine APM (PM2.5). However, in that study, total sampled APM on a filter was digested with acids, and thus only averaged elemental composition in fine APM could be obtained. One of the effective methods to determine the origin of APM is single particle measurement by using SEM-EDX. By using characteristic shapes observed by SEM and marker elements contained in APM measured by EDX, detailed information for source identification can be obtained. In this study, fine APM (PM2.5) was collected at various locations such as roadside, diesel vehicle exhaust, a heavy oil combustion plant and a waste incineration plant as well as ambient atmosphere in Tokyo, and characteristics of fine particles that will be utilized for identification of emission sources are elucidated. Fine particles can be classified into 3 main characteristic shape groups; edge-shaped, cotton-like and spherical. Shape of particles collected in a heavy oil combustion plant and a waste incineration plant was mostly spherical, and these particles may be associated with thermal process. Diesel exhaust particles were predominantly cotton-like which may consist of coagulated nano-sized particles. Most of brake abrasion dusts were edge-shaped, which may be associated with mechanical abrasion of brake pads. In the elemental analysis of fine particles, high concentrations of Sb, Cu, Ti and Ba were detected in brake abrasion dusts. Since these elements are major constituents of brake pads, these can be used for marker elements of brake abrasion dusts. High concentration of C was detected in diesel exhaust particles and oil combustion particles, and thus C can be used for marker elements of their origin. Furthermore, high concentrations of C, Ca and K were detected in fly ash from a waste incineration plant, which

Airborne plutonium-239 and americium-241 concentrations measured from the 125-meter Hanford Meteorological Tower

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sehmel, G.A.

1978-01-01

Airborne plutonium-239 and americium-241 concentrations and fluxes were measured at six heights from 1.9 to 122 m on the Hanford meteorological tower. The data show that plutonium-239 was transported on nonrespirable and small particles at all heights. Airborne americium-241 concentrations on small particles were maximum at the 91 m height.

Integrated Airborne and In-Situ Measurements over Land-Fast Ice near Barrow, AK

NASA Astrophysics Data System (ADS)

Brozena, J. M.; Gardner, J. M.; Liang, R.; Vermillion, M.; Ball, D.; Stoudt, C. A.; Geiger, C. A.; Woods, J. E.; Samluk, J.; Deliberty, T. L.

2013-12-01

During March of 2013, the Naval Research Laboratory, the University of Delaware and the US Naval Academy collected an integrated set of measurements over the largely floating, but land-fast ice near the coast of Barrow, AK. The purpose of the collection was to compare airborne remote sensing methods of collection to in-situ ground-truth measurements. Airborne measurements include scanning LiDAR (Riegl Q 680i), digital photogrammetry (Applanix DSS-439) and a short-pulse (~ 1 nsec) 10 GHz radar altimeter. The LiDAR measures total freeboard (ice + snow) referenced to leads in the ice. The radar measures approximate ice freeboard with the difference with the LiDAR providing an estimate of snow thickness. The freeboard measurements are aimed at estimating ice thickness via estimates of densities and isostasy. The photogrammetry was used to measure ice motion over free-floating sea-ice, but provided only a velocity calibration and general situational awareness over the land-fast ice. Ground measurements were collected along a transect, and included boreholes, snow-thickness (Magnaprobe), and ice thickness (EM31). Airborne data were collected on six overflights of this transect over a three week period. LiDAR swath widths ranged from 200-300m (depending on altitude) and encompassed three grounded ridges which remained essentially stationary over the collection period, that together with the shoreline, provided fixed reference points to compare the heights of the floating ice that varied with the tide (and to some extent the snow conditions). Sampling size or 'footprint' plays a critical role in the attempt to compare in-situ measurements with airborne (or satellite) measurements. Boreholes are point measurements and are difficult enough to obtain, that only a limited number are practical during a survey period. EM31 and Magnaprobe instrumentation allows collection of snow and ice thickness along one-dimensional profiles, and several adjacent profiles can be collected to

Investigation of Ozone Sources in California Using AJAX Airborne Measurements and Models: Implications for Stratospheric Intrusion and Long Range Transport

NASA Technical Reports Server (NTRS)

Ryoo, Ju-Mee; Johnson, Matthew S.; Iraci, Laura T.; Yates, Emma L.; Pierce, R. Bradley; Tanaka, Tomoaki; Gore, Warren

2015-01-01

High ozone concentrations at low altitudes near the surface were detected from airborne Alpha Jet Atmospheric eXperiment (AJAX) measurements on May 30, 2012. We investigate the causes of the elevated ozone concentrations using the airborne measurements and various models. GEOS-chem and WRF-STILT model simulations show that the contribution from local sources is small. From MERRA reanalysis, it is found that high potential vorticity (PV) is observed at low altitudes. This high PV appears to be only partially coming through the stratospheric intrusions because the air inside the high PV region is moist, which shows that mixing appears to be enhanced in the low altitudes. Considering that diabatic heating can also produce high PV in the lower troposphere, high ozone is partially coming through stratospheric intrusion, but this cannot explain the whole ozone concentration in the target areas of the western U.S. A back-trajectory model is utilized to see where the air masses originated. The air masses of the target areas came from the lower stratosphere (LS), upper (UT), mid- (MT), and lower troposphere (LT). The relative number of trajectories coming from LS and UT is low (7.7 and 7.6, respectively) compared to that from LT (64.1), but the relative ozone concentration coming from LS and UT is high (38.4 and 20.95, respectively) compared to that from LT (17.7). The air mass coming from LT appears to be mostly coming from Asia. Q diagnostics show that there is sufficient mixing along the trajectory to indicate that ozone from the different origins is mixed and transported to the western U.S. This study shows that high ozone concentrations can be detected by airborne measurements, which can be analyzed by integrated platforms such as models, reanalysis, and satellite data.

Experimental feasibility of the airborne measurement of absolute oil fluorescence spectral conversion efficiency

NASA Technical Reports Server (NTRS)

Hoge, F. E.; Swift, R. N.

1983-01-01

Airborne lidar oil spill experiments carried out to determine the practicability of the AOFSCE (absolute oil fluorescence spectral conversion efficiency) computational model are described. The results reveal that the model is suitable over a considerable range of oil film thicknesses provided the fluorescence efficiency of the oil does not approach the minimum detection sensitivity limitations of the lidar system. Separate airborne lidar experiments to demonstrate measurement of the water column Raman conversion efficiency are also conducted to ascertain the ultimate feasibility of converting such relative oil fluorescence to absolute values. Whereas the AOFSCE model is seen as highly promising, further airborne water column Raman conversion efficiency experiments with improved temporal or depth-resolved waveform calibration and software deconvolution techniques are thought necessary for a final determination of suitability.

Airborne observations of greenhouse gases in the North Slope of Alaska during summer 2015

NASA Astrophysics Data System (ADS)

Biraud, S.; Torn, M. S.; Sweeney, C.; Springston, S. R.; Sedlacek, A. J., III

2015-12-01

Atmospheric temperatures are warming faster in the Arctic than predicted by climate models. The impact of this warming on permafrost degradation is not well understood, but it is projected to increase carbon decomposition and greenhouse gas production (CO2 and/or CH4) by arctic ecosystems. Airborne observations of atmospheric trace gases, aerosols and cloud properties in North Slopes of Alaska (NSA) are improving our understanding of global climate, with the goal of reducing the uncertainty in global and regional climate simulations and projections. From June 1 through September 15, 2015, the Atmospheric radiation measurement (ARM) airborne facility (AAF) deployed a G1 research aircraft (ARM-ACME-V mission) to fly over the North Slope of Alaska, with occasional vertical profiling to measure trace gas concentrations, between Prudhoe Bay, Oliktok point, Barrow, Atqasuk, Ivotuk, and Toolik Lake. The aircraft payload includes a Picarro and a LGR analyzers for continuous measurements of CO2, CH4, H2O, and CO and N2O mixing ratios, and a 12-flask sampler for analysis of carbon cycle gases (CO2, CO, CH4, N2O, 13CO2, 14CO2, carbonyl sulfide, and trace hydrocarbon species including ethane). The aircraft payload also include measurements of aerosol properties (number size distribution, total number concentration, absorption, and scattering), cloud properties (droplet and ice size information), atmospheric thermodynamic state, and solar/infrared radiation. Preliminary results using CO2, CH4, CO, ethane, and soot spectroscopy observations are used to tease apart biogenic and thermogenic (biomass burning, and oil and gas production) contributions

Column CO2 Measurement From an Airborne Solid-State Double-Pulsed 2-Micron Integrated Path Differential Absorption Lidar

NASA Technical Reports Server (NTRS)

Singh, U. N.; Yu, J.; Petros, M.; Refaat, T. F.; Remus, R.; Fay, J.; Reithmaier, K.

2014-01-01

NASA LaRC is developing and integrating a double-Pulsed 2-micron direct detection IPDA lidar for CO2 column measurement from an airborne platform. The presentation will describe the development of the 2-micrometers IPDA lidar system and present the airborne measurement of column CO2 and will compare to in-situ measurement for various ground target of different reflectivity.

Comprehensive Airborne in Situ Characterization of Atmospheric Aerosols: From Angular Light Scattering to Particle Microphysics

NASA Astrophysics Data System (ADS)

Espinosa, W. Reed

A comprehensive understanding of atmospheric aerosols is necessary both to understand Earth's climate as well as produce skillful air quality forecasts. In order to advance our understanding of aerosols, the Laboratory for Aerosols, Clouds and Optics (LACO) has recently developed the Imaging Polar Nephelometer instrument concept for the in situ measurement of aerosol scattering properties. Imaging Nephelometers provide measurements of absolute phase function and polarized phase function over a wide angular range, typically 3 degrees to 177 degrees, with an angular resolution smaller than one degree. The first of these instruments, the Polarized Imaging Nephelometer (PI-Neph), has taken part in five airborne field experiments and is the only modern aerosol polar nephelometer to have flown aboard an aircraft. A method for the retrieval of aerosol optical and microphysical properties from I-Neph measurements is presented and the results are compared with existing measurement techniques. The resulting retrieved particle size distributions agree to within experimental error with measurements made by commercial optical particle counters. Additionally, the retrieved real part of the refractive index is generally found to be within the predicted error of 0.02 from the expected values for three species of humidified salt particles, whose refractive index is well established. A synopsis is then presented of aerosol scattering measurements made by the PI-Neph during the Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) and the Deep Convection Clouds and Chemistry (DC3) field campaigns. To better summarize these extensive datasets a novel aerosol classification scheme is developed, making use of ancillary data that includes gas tracers, chemical composition, aerodynamic particle size and geographic location, all independent of PI-Neph measurements. Principal component analysis (PCA) is then used to reduce the

The continuous measurement of hydrogen chloride in the ambient atmosphere using the dual isotope infrared absorption technique

NASA Technical Reports Server (NTRS)

Williams, K. G.

1974-01-01

The results of a program to develop a prototype gas filter correlation NDIR analyzer capable of providing the required HCl measurement capability, while maintaining an adequate rejection of any other gases anticipated in the atmosphere are presented. Examples of the performance of the prototype analyzer are presented which show an rms noise equivalent concentration of 0.06 ppm of HCl was achieved while maintaining an electronically determined 10% to 90% time response to gas samples of about 2 seconds. No measureable response was observed to CO2, CO, and H2O while maintaining an adequate rejection of the hydrocarbons, for example CH4 and n-hexane. The experiments were performed which demonstrate that the span stability of the HCl gas filter correlation analyzer is unaffected by the presence of water vapor and which support the belief that the incorporation of a relatively open-volume, multiple path sample cell into the instrument would enable ground station as well as airborne measurements of trace quantities of HCl in the ambient atmosphere to be performed.

Methane Measurements from Space: Technical Challenges and Solutions

NASA Technical Reports Server (NTRS)

Riris, Haris; Numata, Kenji; Wu, Stewart; Gonzalez, Brayler; Rodriguez, Michael; Kawa, Stephan; Mao, Jianping

2017-01-01

We report on an airborne demonstration of atmospheric methane (CH4) measurements with an Integrated Path Differential Absorption (IPDA) lidar using an optical parametric oscillator (OPO) and optical parametric amplifier (OPA) laser transmitter and a sensitive avalanche photo detector. The lidar measures the CH4 absorption at multiple, discrete wavelengths around 1650.9 nm. In September 2015, the instrument was deployed on NASAs DC-8 airborne laboratory and measured atmospheric methane over a wide range of topography and weather conditions from altitudes of 3 km to 13 km. In this paper, we will review the results from our flights, and identify areas of improvement.

Methane measurements from space: technical challenges and solutions

NASA Astrophysics Data System (ADS)

Riris, Haris; Numata, Kenji; Wu, Stewart; Gonzalez, Brayler; Rodriguez, Michael; Kawa, Stephan; Mao, Jianping

2017-05-01

We report on an airborne demonstration of atmospheric methane (CH4) measurements with an Integrated Path Differential Absorption (IPDA) lidar using an optical parametric oscillator (OPO) and optical parametric amplifier (OPA) laser transmitter and a sensitive avalanche photo detector. The lidar measures the CH4 absorption at multiple, discrete wavelengths around 1650.9 nm. In September 2015, the instrument was deployed on NASA's DC-8 airborne laboratory and measured atmospheric methane over a wide range of topography and weather conditions from altitudes of 3 km to 13 km. In this paper, we will review the results from our flights, and identify areas of improvement.

Airborne measurements of Black Carbon using miniature high-performance Aethalometers during global circumnavigation campaign GLWF 2012

NASA Astrophysics Data System (ADS)

Močnik, Griša; Drinovec, Luka; Vidmar, Primož; Lenarčič, Matevž

2013-04-01

While ground-level measurements of atmospheric aerosols are routinely performed around the world, there exists very little data on their vertical and geographical distribution in the global atmosphere. This data is a crucial requirement for our understanding of the dispersion of pollutant species of anthropogenic origin, and their possible effects on radiative forcing, cloud condensation, and other phenomena which can contribute to adverse outcomes. Black Carbon (BC) is a unique tracer for combustion emissions, and can be detected rapidly and with great sensitivity by filter-based optical methods. It has no non-combustion sources and is not transformed by atmospheric processes. Its presence at altitude is unequivocal. Recent technical advances have led to the development of miniaturized instruments which can be operated on ultra-light aircraft, balloons or UAV's. From January to April 2012, a 'Pipistrel Virus' single-seat ultra-light aircraft flew around the world on a photographic and environmental-awareness mission. The flight track covered all seven continents; crossed all major oceans; and operated at altitudes around 3000 m ASL and up to 8900 m ASL. The aircraft carried a specially-developed high-sensitivity miniaturized dual-wavelength Aethalometer, which recorded BC concentrations with very high temporal resolution and sensitivity (see Reference below). We present examples of data from flight tracks over remote oceans, uninhabited land masses, and densely populated areas. Back-trajectories are used to show transport of polluted air masses. Measuring the dependence of the aerosol absorption on the wavelength, we show that aerosols produced during biomass combustion can be transported to high altitude in high concentrations. 1. __, Carbon Sampling Takes Flight, Science 2012, 335, 1286. 2. G. Močnik, L. Drinovec, M. Lenarčič, Airborne measurements of Black Carbon during the GLW Flight using miniature high-performance Aethalometers, accessed 8 January 2013

Fast in situ airborne measurement of ammonia using a mid-infrared off-axis ICOS spectrometer.

PubMed

Leen, J Brian; Yu, Xiao-Ying; Gupta, Manish; Baer, Douglas S; Hubbe, John M; Kluzek, Celine D; Tomlinson, Jason M; Hubbell, Mike R

2013-09-17

A new ammonia (NH3) analyzer was developed based on off-axis integrated cavity output spectroscopy. Its feasibility was demonstrated by making tropospheric measurements in flights aboard the Department of Energy Gulfstream-1 aircraft. The ammonia analyzer consists of an optical cell, quantum-cascade laser, gas sampling system, control and data acquisition electronics, and analysis software. The NH3 mixing ratio is determined from high-resolution absorption spectra obtained by tuning the laser wavelength over the NH3 fundamental vibration band near 9.67 μm. Excellent linearity is obtained over a wide dynamic range (0-101 ppbv) with a response rate (1/e) of 2 Hz and a precision of ±90 pptv (1σ in 1 s). Two research flights were conducted over the Yakima Valley in Washington State. In the first flight, the ammonia analyzer was used to identify signatures of livestock from local dairy farms with high vertical and spatial resolution under low wind and calm atmospheric conditions. In the second flight, the analyzer captured livestock emission signals under windy conditions. Our results demonstrate that this new ammonia spectrometer is capable of providing fast, precise, and accurate in situ observations of ammonia aboard airborne platforms to advance our understanding of atmospheric compositions and aerosol formation.

Simultaneous Red - Blue Lidar and Airborne Impactor Measurements

NASA Technical Reports Server (NTRS)

McCormick, M. P.; Blifford, I. H.; Fuller, W. H.; Grams, G. W.

1973-01-01

Simultaneous two-color (0.6943 micrometers and 0.3472 micrometers) LIDAR measurements were made in the troposphere and lower stratosphere over Boulder, Colorado during March 1973. In addition, on the evening of March 26, airborne single-stage impactor measurements were made at four altitudes-- 10,500, 25,000, 33,000 and 43,000 feet MSL. These data were integrated at constant altitude for 15,45, 45, and 60 minutes respectively. The LIDAR data were taken with Langley's 48" LIDAR using a dichroic beamsplitter to separate the return at 0.6943 micrometers and 0.3472 micrometers. The analog waveforms for both colors were digitized simultaneously; one on an NCAR data acquisition system and the other on the 48" Langley data acquisition system. A discussion of the preliminary results from these measurements will be presented.

Lord Kelvin's atmospheric electricity measurements

NASA Astrophysics Data System (ADS)

Aplin, Karen; Harrison, R. Giles; Trainer, Matthew; Hough, James

2013-04-01

Lord Kelvin (William Thomson), one of the greatest Victorian scientists, made a substantial but little-recognised contribution to geophysics through his work on atmospheric electricity. He developed sensitive instrumentation for measuring the atmospheric electric field, including invention of a portable electrometer, which made mobile measurements possible for the first time. Kelvin's measurements of the atmospheric electric field in 1859, made during development of the portable electrometer, can be used to deduce the substantial levels of particulate pollution blown over the Scottish island of Arran from the industrial mainland. Kelvin was also testing the electrometer during the largest solar flare ever recorded, the "Carrington event" in the late summer of 1859. Subsequently, Lord Kelvin also developed a water dropper sensor, and employed photographic techniques for "incessant recording" of the atmospheric electric field, which led to the long series of measurements recorded at UK observatories for the remainder of the 19th and much of the 20th century. These data sets have been valuable in both studies of historical pollution and cosmic ray effects on atmospheric processes.

NASA Langley Atmospheric Science Data Center Toolsets for Airborne Data (TAD): User Interface Design and Development

NASA Astrophysics Data System (ADS)

Beach, A. L., III; Early, A. B.; Chen, G.; Parker, L.

2014-12-01

NASA has conducted airborne tropospheric chemistry studies for about three decades. These field campaigns have generated a great wealth of observations, which are characterized by a wide range of trace gases and aerosol properties. The airborne observational data have often been used in assessment and validation of models and satellite instruments. The ASDC Toolset for Airborne Data (TAD) is being designed to meet the user community needs for manipulating aircraft data for scientific research on climate change and air quality relevant issues. Given the sheer volume of data variables across field campaigns and instruments reporting data on different time scales, this data is often difficult and time-intensive for researchers to analyze. The TAD web application is designed to provide an intuitive user interface (UI) to facilitate quick and efficient discovery from a vast number of airborne variables and data. Users are given the option to search based on high-level parameter groups, individual common names, mission and platform, as well as date ranges. Experienced users can immediately filter by keyword using the global search option. Once the user has chosen their required variables, they are given the option to either request PI data files based on their search criteria or create merged data, i.e. geo-located data from one or more measurement PIs. The purpose of the merged data feature is to allow users to compare data from one flight, as not all data from each flight is taken on the same time scale. Time bases can be continuous or based on the time base from one of the measurement time scales and intervals. After an order is submitted and processed, an ASDC email is sent to the user with a link for data download. The TAD user interface design, application architecture, and proposed future enhancements will be presented.

Measurements of Ocean Surface Scattering Using an Airborne 94-GHz Cloud Radar: Implication for Calibration of Airborne and Spaceborne W-band Radars

NASA Technical Reports Server (NTRS)

Li, Li-Hua; Heymsfield, Gerald M.; Tian, Lin; Racette, Paul E.

2004-01-01

Scattering properties of the Ocean surface have been widely used as a calibration reference for airborne and spaceborne microwave sensors. However, at millimeter-wave frequencies, the ocean surface backscattering mechanism is still not well understood, in part, due to the lack of experimental measurements. During the Cirrus Regional Study of Tropical Anvils and Cirrus Layers-Florida Area Cirrus Experiment (CRYSTAL-FACE), measurements of ocean surface backscattering were made using a 94-GHz (W-band) cloud radar onboard a NASA ER-2 high-altitude aircraft. The measurement set includes the normalized Ocean surface cross section over a range of the incidence angles under a variety of wind conditions. Analysis of the radar measurements shows good agreement with a quasi-specular scattering model. This unprecedented dataset enhances our knowledge about the Ocean surface scattering mechanism at 94 GHz. The results of this work support the proposition of using the Ocean surface as a calibration reference for airborne millimeter-wave cloud radars and for the ongoing NASA CloudSat mission, which will use a 94-GHz spaceborne cloud radar for global cloud measurements.

Quantifying sources and sinks of reactive gases in the lower atmosphere using airborne flux observations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolfe, Glenn; Hanisco, T. F.; Atkinson, H. L.

Atmospheric composition is governed by the interplay of emissions, chemistry, deposition, and transport. Substantial questions surround each of these processes, especially in forested environments with strong biogenic emissions. Utilizing aircraft observations acquired over a forest in the southeast U.S., we calculate eddy covariance fluxes for a suite of reactive gases and apply the synergistic information derived from this analysis to quantify emission and deposition fluxes, oxidant concentrations, aerosol uptake coefficients, and other key parameters. Evaluation of results against state-of-the-science models and parameterizations provides insight into our current understanding of this system and frames future observational priorities. As a near-direct measurementmore » of fundamental process rates, airborne fluxes offer a new tool to improve biogenic and anthropogenic emissions inventories, photochemical mechanisms, and deposition parameterizations.« less

Airborne spectral Measurements of Surface-Atmosphere Anisotropy for Several Surfaces and Ecosystem over Southern Africa

NASA Technical Reports Server (NTRS)

Gatebe, Charles K.; King, M. D.; Arnold, G. T.; Li, J. Y.; Lau, William K. M. (Technical Monitor)

2001-01-01

The Cloud Absorption Radiometer (CAR) was flown aboard the University of Washington Convair CV-580 research aircraft and took measurements on 23 flights between August 15 and September 16. On 12 of those flights, BRF measurements were obtained over different natural surfaces and ecosystem in southern Africa. The BRF measurements were done to characterize surface anisotropy in support of SAFARI 2000 science objectives principally to validate products from NASA's EOS satellites, and to parameterize and validate BRF models. In this paper we present results of BRFs taken over two EOS validation sites: Skukuza tower, South Africa (25.0 deg S, 31.5 deg E) and Mongu tower, Zambia (15.4 deg S, 23.3 deg E). Additional sites are also considered and include, Maun tower, Botswana (20.0 deg S, 23.5 deg E), Sowa Pan, Botswana (20.6 deg S, 26.2 deg E) and Etosha Pan, Namibia (19.0 deg S, 16.0 deg E). The CAR is capable of measuring scattered light in fourteen spectral bands. The scan mirror, rotating at 100 rpm, directs the light into a Dall-Kirkham telescope where the beam is split into nine paths. Eight light beams pass through beam splitters, dichroics, and lenses to individual detectors (0.34-1.27 micrometers), and finally are registered by eight data channels. They are sampled simultaneously and continuously. The ninth beam passes through a spinning filter wheel to an InSb detector cooled by a Stirling cycle cooler. Signals registered by the ninth data channel are selected from among six spectral channels (1.55-2.30 micrometers). The filter wheel can either cycle through all six spectral bands at a prescribed interval (usually changing filter every fifth scan line), or lock onto any one of the six spectral bands and sample it continuously. To measure the BRF of the surface-atmosphere system, the University of Washington CV-580 had to bank at a comfortable roll angle of approximately 20 degrees and fly in a circle about 3 km in diameter above the surface for roughly two

Wildfire smoke in the Siberian Arctic in summer: source characterization and plume evolution from airborne measurements

NASA Astrophysics Data System (ADS)

Paris, J.-D.; Stohl, A.; Nédélec, P.; Arshinov, M. Yu.; Panchenko, M. V.; Shmargunov, V. P.; Law, K. S.; Belan, B. D.; Ciais, P.

2009-09-01

We present airborne measurements of carbon dioxide (CO2), carbon monoxide (CO), ozone (O3), equivalent black carbon (EBC) and ultra fine particles over North-Eastern Siberia in July 2008 performed during the YAK-AEROSIB/POLARCAT experiment. During a "golden day" (11 July 2008) a number of biomass burning plumes were encountered with CO concentration enhancements of up to 500 ppb relative to a background of 90 ppb. Number concentrations of aerosols in the size range 3.5-200 nm peaked at 4000 cm-3 and the EBC content reached 1.4 μg m-3. These high concentrations were caused by forest fires in the vicinity of the landing airport in Yakutsk where during the descent measurements in fresh smoke could be made. We estimate a combustion efficiency of 90±3% based on CO and CO2 measurements. The emission factor of CO emitted was 59.6±15.2 g CO per kilogram of dry matter burned, suggesting an increase in the average northern hemispheric CO concentration of 3.0-7.2 ppb per million hectares of Siberian forest burned. For BC, we estimate an emission factor of 0.52±0.07 g BC kg-1, comparable to values reported in the literature. The emission ratio of ultra-fine particles (3.5-200 nm) was 26 cm-3 (ppb CO)-1, consistent with other airborne studies. The transport of identified biomass burning plumes was investigated using the FLEXPART Lagrangian model. Based on sampling of wildfire plumes from the same source but with different atmospheric ages derived from FLEXPART, we estimate that the e-folding lifetimes of EBC and ultra fine particles (between 3.5 and 200 nm in size) against removal and growth processes are 5.1 and 5.5 days, respectively, supporting lifetimes estimates used in various modelling studies.

Wildfire smoke in the Siberian Arctic in summer: source characterization and plume evolution from airborne measurements

NASA Astrophysics Data System (ADS)

Paris, J.-D.; Stohl, A.; Nédélec, P.; Arshinov, M. Yu.; Panchenko, M. V.; Shmargunov, V. P.; Law, K. S.; Belan, B. D.; Ciais, P.

2009-12-01

We present airborne measurements of carbon dioxide (CO2), carbon monoxide (CO), ozone (O3), equivalent black carbon (EBC) and ultra fine particles over North-Eastern Siberia in July 2008 performed during the YAK-AEROSIB/POLARCAT experiment. During a "golden day" (11 July 2008) a number of biomass burning plumes were encountered with CO mixing ratio enhancements of up to 500 ppb relative to a background of 90 ppb. Number concentrations of aerosols in the size range 3.5-200 nm peaked at 4000 cm-3 and the EBC content reached 1.4 μg m-3. These high concentrations were caused by forest fires in the vicinity of the landing airport in Yakutsk where measurements in fresh smoke could be made during the descent. We estimate a combustion efficiency of 90 ± 3% based on CO and CO2 measurements and a CO emission factor of 65.5 ± 10.8 g CO per kilogram of dry matter burned. This suggests a potential increase in the average northern hemispheric CO mixing ratio of 3.0-7.2 ppb per million hectares of Siberian forest burned. For BC, we estimate an emission factor of 0.52 ± 0.07 g BC kg-1, comparable to values reported in the literature. The emission ratio of ultra-fine particles (3.5-200 nm) was 26 cm-3 (ppb CO)-1, consistent with other airborne studies. The transport of identified biomass burning plumes was investigated using the FLEXPART Lagrangian model. Based on sampling of wildfire plumes from the same source but with different atmospheric ages derived from FLEXPART, we estimate that the e-folding lifetimes of EBC and ultra fine particles (between 3.5 and 200 nm in size) against removal and growth processes are 5.1 and 5.5 days respectively, supporting lifetime estimates used in various modelling studies.

Airborne intercomparison of nitric oxide measurement techniques

NASA Technical Reports Server (NTRS)

Hoell, James M., Jr.; Gregory, Gerald L.; Mcdougal, David S.; Torres, Arnold L.; Davis, Douglas D.

1987-01-01

Results from an airborne intercomparison of techniques to measure tropospheric levels of nitric oxide (NO) are discussed. The intercomparison was part of the National Aeronautics and Space Administration's Global Tropospheric Experiment and was conducted during missions flown in the fall of 1983 and spring of 1984. Instruments intercompared included a laser-induced fluorescence (LIF) system and two chemiluminescence instruments (CL). NO mixing ratios from below 5 pptv (parts per trillion by volume) to greater than 100 pptv were reported, with the majority less than 20 pptv. Good correlation was observed between the measurements reported by the CL and LIF techniques. The general level of agreement observed for the ensemble of measurements obtained during the two missions provides the basis from which one can conclude that equally 'valid' measurements of background levels of NO can be expected from either CL or LIF instruments. At the same time the periods of disagreement that were observed between the CL and LIF instruments as well as between the two CL instruments highlight the difficulty of obtaining reliable measurements with NO mixing ratios in the 5-20 pptv range and emphasize the vigilance that should be maintained in future NO measurements.

Atmospheric Ionization Measurements

NASA Astrophysics Data System (ADS)

Slack, Thomas; Mayes, Riley

2015-04-01

The measurement of atmospheric ionization is a largely unexplored science that potentially holds the key to better understanding many different geophysical phenomena through this new and valuable source of data. Through the LaACES program, which is funded by NASA through the Louisiana Space Consortium, students at Loyola University New Orleans have pursued the goal of measuring high altitude ionization for nearly three years, and were the first to successfully collect ionization data at altitudes over 30,000 feet using a scientific weather balloon flown from the NASA Columbia Scientific Ballooning Facility in Palestine, TX. In order to measure atmospheric ionization, the science team uses a lightweight and highly customized sensor known as a Gerdien condenser. Among other branches of science the data is already being used for, such as the study of aerosol pollution levels in the atmosphere, the data may also be useful in meteorology and seismology. Ionization data might provide another variable with which to predict weather or seismic activity more accurately and further in advance. Thomas Slack and Riley Mayes have served as project managers for the experiment, and have extensive knowledge of the experiment from the ground up. LaSPACE Louisiana Space Consortium.

Validation of aerosol extinction and water vapor profiles from routine Atmospheric Radiation Measurement Program Climate Research Facility measurements

NASA Astrophysics Data System (ADS)

Schmid, Beat; Flynn, Connor J.; Newsom, Rob K.; Turner, David D.; Ferrare, Richard A.; Clayton, Marian F.; Andrews, Elisabeth; Ogren, John A.; Johnson, Roy R.; Russell, Philip B.; Gore, Warren J.; Dominguez, Roseanne

2009-11-01

The accuracy with which vertical profiles of aerosol extinction σep(λ) can be measured using routine Atmospheric Radiation Measurement Program (ARM) Climate Research Facility (ACRF) measurements and was assessed using data from two airborne field campaigns, the ARM Aerosol Intensive Operation Period (AIOP, May 2003), and the Aerosol Lidar Validation Experiment (ALIVE, September 2005). This assessment pertains to the aerosol at its ambient concentration and thermodynamic state (i.e., σep(λ) either free of or corrected for sampling artifacts) and includes the following ACRF routine methods: Raman lidar, micropulse lidar (MPL), and in situ aerosol profiles (IAP) with a small aircraft. Profiles of aerosol optical depth τp(λ), from which the profiles of σep(λ) are derived through vertical differentiation, were measured by the NASA Ames Airborne Tracking 14-channel Sun photometer (AATS-14); these data were used as benchmark in this evaluation. The ACRF IAP σep(550 nm) were lower by 11% (during AIOP) and higher by 1% (during ALIVE) when compared to AATS-14. The ACRF MPL σep(523 nm) measurements were higher by 24% (AIOP) and 19-21% (ALIVE) compared to AATS-14, but the correlation improved significantly during ALIVE. In the AIOP, a second MPL operated by NASA showed a smaller positive bias (13%) with respect to AATS-14. The ACRF Raman lidar σep(355 nm) measurements were larger by 54% (AIOP) and by 6% (ALIVE) compared to AATS-14. The large bias in the Raman lidar measurements during AIOP stemmed from a gradual loss of Raman lidar sensitivity starting about the end of 2001 going unnoticed until after AIOP. A major refurbishment and upgrade of the instrument and improvements to a data processing algorithm led to the significant improvement and very small bias in ALIVE. Finally, we find that during ALIVE the Raman lidar water vapor densities ρw are 8% larger when compared to AATS-14, whereas in situ measured ρw aboard two different aircraft are smaller than the

Device and method for accurately measuring concentrations of airborne transuranic isotopes

DOEpatents

McIsaac, Charles V.; Killian, E. Wayne; Grafwallner, Ervin G.; Kynaston, Ronnie L.; Johnson, Larry O.; Randolph, Peter D.

1996-01-01

An alpha continuous air monitor (CAM) with two silicon alpha detectors and three sample collection filters is described. This alpha CAM design provides continuous sampling and also measures the cumulative transuranic (TRU), i.e., plutonium and americium, activity on the filter, and thus provides a more accurate measurement of airborne TRU concentrations than can be accomplished using a single fixed sample collection filter and a single silicon alpha detector.

Device and method for accurately measuring concentrations of airborne transuranic isotopes

DOEpatents

McIsaac, C.V.; Killian, E.W.; Grafwallner, E.G.; Kynaston, R.L.; Johnson, L.O.; Randolph, P.D.

1996-09-03

An alpha continuous air monitor (CAM) with two silicon alpha detectors and three sample collection filters is described. This alpha CAM design provides continuous sampling and also measures the cumulative transuranic (TRU), i.e., plutonium and americium, activity on the filter, and thus provides a more accurate measurement of airborne TRU concentrations than can be accomplished using a single fixed sample collection filter and a single silicon alpha detector. 7 figs.

Hyper-spectral Atmospheric Sounding. Appendixes 1

NASA Technical Reports Server (NTRS)

Smith, W. L.; Zhou, D. K.; Revercomb, H. E.; Huang, H. L.; Antonelli, P.; Mango, S. A.

2002-01-01

The Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS) is the first hyper-spectral remote sounding system to be orbited aboard a geosynchronous satellite. The GETS is designed to obtain revolutionary observations of the four dimensional atmospheric temperature, moisture, and wind structure as well as the distribution of the atmospheric trace gases, CO and O3. Although GIFTS will not be orbited until 2006-2008, a glimpse at the its measurement capabilities has been obtained by analyzing data from the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Airborne Sounder Test-bed-Interferometer (NAST-I) and Aqua satellite Atmospheric Infrared Sounder (AIRS). In this paper we review the GIFTS experiment and empirically assess measurement expectations based on meteorological profiles retrieved from the NAST aircraft and Aqua satellite AIRS spectral radiances.

Retrievals with the Infrared Atmospheric Sounding Interferometer

NASA Technical Reports Server (NTRS)

Zhou, Daniel K.; Liu, Xu; Larar, Allen M.; Smith, William L.; Taylor, Jonathan P.; Schlussel, Peter; Strow, L. Larrabee; Calbet, Xavier; Mango, Stephen A.

2007-01-01

The Infrared Atmospheric Sounding Interferometer (IASI) on the MetOp satellite was launched on October 19, 2006. The Joint Airborne IASI Validation Experiment (JAIVEx) was conducted during April 2007 mainly for validation of the IASI on the MetOp satellite. IASI possesses an ultra-spectral resolution of 0.25/cm and a spectral coverage from 645 to 2760/cm. Ultraspectral resolution infrared spectral radiance obtained from near nadir observations provide atmospheric, surface, and cloud property information. An advanced retrieval algorithm with a fast radiative transfer model, including cloud effects, is used for atmospheric profile and cloud parameter retrieval. Preliminary retrievals of atmospheric soundings, surface properties, and cloud optical/microphysical properties with the IASI observations during the JAIVEx are obtained and presented. These retrievals are further inter-compared with those obtained from airborne FTS system, such as the NPOESS Airborne Sounder Testbed Interferometer (NAST-I), dedicated dropsondes, radiosondes, and ground based Raman Lidar. The capabilities of satellite ultra-spectral sounder such as the IASI are investigated.

A new method for GPS-based wind speed determinations during airborne volcanic plume measurements

USGS Publications Warehouse

Doukas, Michael P.

2002-01-01

Begun nearly thirty years ago, the measurement of gases in volcanic plumes is today an accepted technique in volcano research. Volcanic plume measurements, whether baseline gas emissions from quiescent volcanoes or more substantial emissions from volcanoes undergoing unrest, provide important information on the amount of gaseous output of a volcano to the atmosphere. Measuring changes in gas emission rates also allows insight into eruptive behavior. Some of the earliest volcanic plume measurements of sulfur dioxide were made using a correlation spectrometer (COSPEC). The COSPEC, developed originally for industrial pollution studies, is an upward-looking optical spectrometer tuned to the ultraviolet absorption wavelength of sulfur dioxide (Millán and Hoff, 1978). In airborne mode, the COSPEC is mounted in a fixed-wing aircraft and flown back and forth just underneath a volcanic plume, perpendicular to the direction of plume travel (Casadevall and others, 1981; Stoiber and others, 1983). Similarly, for plumes close to the ground, the COSPEC can be mounted in an automobile and driven underneath a plume if a suitable road system is available (Elias and others, 1998). The COSPEC can also be mounted on a tripod and used to scan a volcanic plume from a fixed location on the ground, although the effectiveness of this configuration declines with distance from the plume (Kyle and others, 1990). In the 1990’s, newer airborne techniques involving direct sampling of volcanic plumes with infrared spectrometers and electrochemical sensors were developed in order to measure additional gases such as CO2 and H2S (Gerlach and others, 1997; Gerlach and others, 1999; McGee and others, 2001). These methods involve constructing a plume cross-section from several measurement traverses through the plume in a vertical plane. Newer instruments such as open-path Fourier transform infrared (FTIR) spectrometers are now being used to measure the gases in volcanic plumes mostly from fixed

Airborne trace contaminants of possible interest in CELSS

NASA Technical Reports Server (NTRS)

Garavelli, J. S.

1986-01-01

One design goal of Closed Ecological Life Support Systems (CELSS) for long duration space missions is to maintain an atmosphere which is healthy for all the desirable biological species and not deleterious to any of the mechanical components in that atmosphere. CELESS design must take into account the interactions of at least six major components; (1) humans and animals, (2) higher plants, (3) microalgae, (4) bacteria and fungi, (5) the waste processing system, and (6) other mechanical systems. Each of these major components can be both a source and a target of airborne trace contaminants in a CELSS. A range of possible airborne trace contaminants is discussed within a chemical classification scheme. These contaminants are analyzed with respect to their probable sources among the six major components and their potential effects on those components. Data on airborne chemical contaminants detected in shuttle missions is presented along with this analysis. The observed concentrations of several classes of compounds, including hydrocarbons, halocarbons, halosilanes, amines and nitrogen oxides, are considered with respect to the problems which they present to CELSS.

Developments in Airborne Oceanography and Air-Sea Interaction

NASA Astrophysics Data System (ADS)

Melville, W. K.

2014-12-01

One of the earliest ocean-related flights was that of Amundsen to be first across the North Pole and Arctic from Svalbard to Alaska in the airship Norge in 1926. Twenty five years later Cox & Munk flew a B-17G "Flying Fortress" bomber over Hawaiian waters measuring sea surface slope statistics from photographs of sun glitter and wind speed from a yacht. The value of Cox & Munk's "airborne oceanography" became apparent another twenty five years later with the short-lived Seasat microwave remote-sensing mission, since interpretation of the Seasat data in geophysical variables required scattering theories that relied on their data. The universal acceptance of remote sensing in oceanography began in 1992 with the launch of, and successful analysis of sea surface height data from, the Topex/Poseidon radar altimeter. With that and the development of more realistic coupled atmosphere-ocean models it became apparent that our understanding of weather and climate variability in both the atmosphere and the ocean depends crucially on our ability to measure processes in boundary layers spanning the interface. Ten years ago UNOLS formed the Scientific Committee for Oceanographic Aircraft Research (SCOAR) "...to improve access to research aircraft facilities for ocean sciences"; an attempt to make access to aircraft as easy as access to research vessels. SCOAR emphasized then that "Aircraft are ideal for both fast-response investigations and routine, long-term measurements, and they naturally combine atmospheric measurements with oceanographic measurements on similar temporal and spatial scales." Since then developments in GPS positioning and miniaturization have made scientific measurements possible from smaller and smaller platforms, including the transition from manned to unmanned aerial vehicles (UAVs). Furthermore, ship-launched and recovered UAVs have demonstrated how they can enhance the capabilities and reach of the research vessels, "projecting" research and science

Airborne survey of major air basins in California

NASA Technical Reports Server (NTRS)

Gloria, H. R.; Bradburn, G.; Reinisch, R. F.; Pitts, J. N., Jr.; Behar, J. V.; Zafonte, L.

1974-01-01

An instrumented aircraft was used to study the chemical and transport properties of air pollution in two major urban centers in California and to survey certain aspects of air pollution within this state. State-of-the-art measurement techniques and sampling procedures are discussed. It is found that meteorological transport mechanisms are better portrayed by vertical pollutant profiles. Airborne measurements define the nature of the mixing layer for atmospheric pollutants. Results show that the pollutants are found to be concentrated in distinct layers up to at least 18,000 feet and the O3 buildup occurring in advected air masses is a result of a continuous photochemical aging of air mass.

Measurement of atmospheric water vapor, leaf liquid water and reflectance with AVIRIS in the Boreal Ecosystem-Atmosphere Study: Initial results

NASA Technical Reports Server (NTRS)

Green, Robert O.; Conel, James E.; Roberts, Dar A.

1995-01-01

The Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) acquired data as part of the Boreal Ecosystem-Atmosphere Study (BOREAS) in 1994. Flights occurred over the northern study area (NSA) in the region of 56 degrees north latitude and 98.5 degrees west longitude and over the southern study area (SSA) at 54 degrees north latitude and 105 degrees west longitude. These data will be used to directly derive spectral properties of the surface and atmosphere and to provide supporting data for other instruments, models, and experiments in support of the BOREAS objectives. We present a preliminary evaluation of the AVIRIS data collected in BOREAS in terms of the AVIRIS-derived parameters: water vapor, leaf water, and apparent spectral reflectance.

Airborne seeker evaluation and test system

NASA Astrophysics Data System (ADS)

Jollie, William B.

1991-08-01

The Airborne Seeker Evaluation Test System (ASETS) is an airborne platform for development, test, and evaluation of air-to-ground seekers and sensors. ASETS consists of approximately 10,000 pounds of equipment, including sixteen racks of control, display, and recording electronics, and a very large stabilized airborne turret, all carried by a modified C- 130A aircraft. The turret measures 50 in. in diameter and extends over 50 in. below the aircraft. Because of the low ground clearance of the C-130, a unique retractor mechanism was designed to raise the turret inside the aircraft for take-offs and landings, and deploy the turret outside the aircraft for testing. The turret has over 7 cubic feet of payload space and can accommodate up to 300 pounds of instrumentation, including missile seekers, thermal imagers, infrared mapping systems, laser systems, millimeter wave radar units, television cameras, and laser rangers. It contains a 5-axis gyro-stabilized gimbal system that will maintain a line of sight in the pitch, roll, and yaw axes to an accuracy better than +/- 125 (mu) rad. The rack-mounted electronics in the aircraft cargo bay can be interchanged to operate any type of sensor and record the data. Six microcomputer subsystems operate and maintain all of the system components during a test mission. ASETS is capable of flying at altitudes between 200 and 20,000 feet, and at airspeeds ranging from 100 to 250 knots. Mission scenarios can include air-to-surface seeker testing, terrain mapping, surface target measurement, air-to-air testing, atmospheric transmission studies, weather data collection, aircraft or missile tracking, background signature measurements, and surveillance. ASETS is fully developed and available to support test programs.

Spatial variations in atmospheric CO2 concentrations during the ARCTAS-CARB 2008 Summer Campaign

NASA Astrophysics Data System (ADS)

Vadrevu, K. P.; Choi, Y.; Vay, S. A.

2009-12-01

The Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) was a major NASA field campaign designed to understand the transport and transformation of trace gases and aerosols on transcontinental and intercontinental scales and their impact on the composition of the arctic atmosphere and climate. Preceding the summer ARCTAS deployment, measurements were conducted over the state of California in collaboration with the California Air Resources Board (CARB) utilizing the airborne chemistry payload already integrated on the NASA DC-8. In situ CO2 measurements were made using a modified infrared CO2 gas analyzer having a precision of 0.1 ppmv and accuracy of ±0.25 ppmv traceable to the WMO scale. This analysis focuses on the atmospheric CO2 variability and biospheric/atmospheric exchange over California. We used multi-satellite remote sensing datasets to relate airborne observations of CO2 to infer sources and sinks. Georeferencing the airborne CO2 transect data with the LANDSAT derived land cover datasets over California suggested significant spatial variations. The airborne CO2 concentrations were found to be 375-380ppm over the Pacific ocean, 385-391ppm in the highly vegetated agricultural areas, 400-420 in the near coastal areas and greater than 425ppmv in the urban areas. Analysis from MODIS fire products suggested significant fires in northern California. CO2 emissions exceeded 425ppmv in the fire affected regions, where mostly Douglas and White Fir conifers and mixed Chaparral vegetation was burnt. Analysis from GOES-East and GOES-West visible satellite imagery suggested significant smoke plumes moving from northern California towards Nevada and Idaho. To infer the biospheric uptake of CO2, we tested the potential correlations between airborne CO2 data and MODIS normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI). Results suggested significant anti-correlations between the airborne CO2 data and

TRACE-P OH and HO2 Measurements with the Airborne Tropospheric Hydrogen Oxides Sensor (ATHOS) on the DC-8

NASA Technical Reports Server (NTRS)

Brune, William H.; Martinez-Harder, Monica; Harder, Hartwig

2004-01-01

The Airborne Tropospheric Hydrogen Oxides Sensor (ATHOS) measures OH and HO2 from the NASA DC-8. This instrument detects OH by laser induced fluorescence (LIF) in detection chambers at low pressure and detects HO2 by chemical conversion with NO followed by LIF detection. The demonstrated detection limit (S/N=2, 5 min.) for OH is about 0.005 pptv (1x10(exp 6)/cu cm at 2 km altitude) and for HO2 is 0.05 pptv (1x10(exp 6)/cu cm at 2 km altitude). We will use ATHOS to measure OH, HO2, and HO2/OH during TRACE- P, analyze these results by comparing them against fundamental relationships and computer models, and publish the analyses. TRACE-P HO(x), measurements will help develop a clearer picture of the atmospheric oxidation and 0 3 production that occur as Asian pollution spreads across the Pacific Ocean.

Atmospheric CO2 Column Measurements with an Airborne Intensity-Modulated Continuous-Wave 1.57-micron Fiber Laser Lidar

NASA Technical Reports Server (NTRS)

Dobler, Jeremy T.; Harrison, F. Wallace; Browell, Edward V.; Lin, Bing; McGregor, Doug; Kooi, Susan; Choi, Yonghoon; Ismail, Syed

2013-01-01

The 2007 National Research Council (NRC) Decadal Survey on Earth Science and Applications from Space recommended Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) as a mid-term, Tier II, NASA space mission. ITT Exelis, formerly ITT Corp., and NASA Langley Research Center have been working together since 2004 to develop and demonstrate a prototype Laser Absorption Spectrometer for making high-precision, column CO2 mixing ratio measurements needed for the ASCENDS mission. This instrument, called the Multifunctional Fiber Laser Lidar (MFLL), operates in an intensity-modulated, continuous-wave mode in the 1.57- micron CO2 absorption band. Flight experiments have been conducted with the MFLL on a Lear-25, UC-12, and DC-8 aircraft over a variety of different surfaces and under a wide range of atmospheric conditions. Very high-precision CO2 column measurements resulting from high signal-to-noise (great than 1300) column optical depth measurements for a 10-s (approximately 1 km) averaging interval have been achieved. In situ measurements of atmospheric CO2 profiles were used to derive the expected CO2 column values, and when compared to the MFLL measurements over desert and vegetated surfaces, the MFLL measurements were found to agree with the in situ-derived CO2 columns to within an average of 0.17% or approximately 0.65 ppmv with a standard deviation of 0.44% or approximately 1.7 ppmv. Initial results demonstrating ranging capability using a swept modulation technique are also presented.

Differential Absorption Lidar (DIAL) Measurements from Air and Space

NASA Technical Reports Server (NTRS)

Browell, E. V.; Ismail, S.; Grant, W. B.

1998-01-01

Differential absorption lidar (DIAL) systems have been used for the measurement of ozone, water vapor, and aerosols from aircraft platforms for over 18 years, yielding new insights into atmospheric chemistry, composition, and dynamics in large-scale field experiments conducted all over the world. The successful deployment of the lidar in-space technology experiment (LITE) in September 1994 demonstrated that space-based lidars can also collect valuable information on the global atmosphere. This paper reviews some of the contributions of the NASA Langley Research Center's airborne ozone and water vapor DIAL systems and space-based LITE system to the understanding of the atmosphere and discusses the feasibility and advantages of putting DIAL systems in space for routine atmospheric measurements of ozone and/or water vapor and aerosols and clouds. The technology and applications of the differential absorption lidar (DIAL) technique have progressed significantly since the first DIAL measurements of Schotland, and airborne DIAL measurements of ozone and water vapor are frequently being made in a wide range of field experiments. In addition, plans are underway to develop DIAL systems for use on satellites for continuous global measurements. This paper will highlight the history of airborne lidar and DIAL systems, summarize the major accomplishments of the NASA Langley DIAL program, and discuss specifications and goals for DIAL systems in space.

Airborne and satellite remote sensing of the mid-infrared water vapour continuum.

PubMed

Newman, Stuart M; Green, Paul D; Ptashnik, Igor V; Gardiner, Tom D; Coleman, Marc D; McPheat, Robert A; Smith, Kevin M

2012-06-13

Remote sensing of the atmosphere from space plays an increasingly important role in weather forecasting. Exploiting observations from the latest generation of weather satellites relies on an accurate knowledge of fundamental spectroscopy, including the water vapour continuum absorption. Field campaigns involving the Facility for Airborne Atmospheric Measurements research aircraft have collected a comprehensive dataset, comprising remotely sensed infrared radiance observations collocated with accurate measurements of the temperature and humidity structure of the atmosphere. These field measurements have been used to validate the strength of the infrared water vapour continuum in comparison with the latest laboratory measurements. The recent substantial changes to self-continuum coefficients in the widely used MT_CKD (Mlawer-Tobin-Clough-Kneizys-Davies) model between 2400 and 3200 cm(-1) are shown to be appropriate and in agreement with field measurements. Results for the foreign continuum in the 1300-2000 cm(-1) band suggest a weak temperature dependence that is not currently included in atmospheric models. A one-dimensional variational retrieval experiment is performed that shows a small positive benefit from using new laboratory-derived continuum coefficients for humidity retrievals.

Progress on Development of an Airborne Two-Micron IPDA Lidar for Water Vapor and Carbon Dioxide Column Measurements

NASA Technical Reports Server (NTRS)

Singh, Upendra N.; Petros, Mulugeta; Refaat, Tamer F.; Yu, Jirong; Antill, Charles W.; Taylor, Bryant D.; Bowen, Stephen C.; Welters, Angela M.; Remus, Ruben G.; Wong, Teh-Hwa;

Infrared lidars for atmospheric remote sensing

NASA Technical Reports Server (NTRS)

Menzies, Robert T.

1991-01-01

Lidars using pulsed TEA-CO2 transmitters and coherent receivers have been developed at JPL and used to measure atmospheric backscatter and extinction at wavelengths in the 9-11 micron region. The global winds measurement application of coherent Doppler lidar requires intensive study of the global climatology of aerosol and cloud backscatter and extinction. An airborne lidar was recently flown on the NASA DC-8 research aircraft for operation during two Pacific circumnavigation missions. The instrument characteristics, as well as representative measurement results, are discussed.

Airborne Measurements of CO2 Column Absorption and Range Using a Pulsed Direct-Detection Integrated Path Differential Absorption Lidar

NASA Technical Reports Server (NTRS)

Abshire, James B.; Riris, Haris; Weaver, Clark J.; Mao, Jianping; Allan, Graham R.; Hasselbrack, William E.; Browell, Edward V.

2013-01-01

We report on airborne CO2 column absorption measurements made in 2009 with a pulsed direct-detection lidar operating at 1572.33 nm and utilizing the integrated path differential absorption technique. We demonstrated these at different altitudes from an aircraft in July and August in flights over four locations in the central and eastern United States. The results show clear CO2 line shape and absorption signals, which follow the expected changes with aircraft altitude from 3 to 13 km. The lidar measurement statistics were also calculated for each flight as a function of altitude. The optical depth varied nearly linearly with altitude, consistent with calculations based on atmospheric models. The scatter in the optical depth measurements varied with aircraft altitude as expected, and the median measurement precisions for the column varied from 0.9 to 1.2 ppm. The altitude range with the lowest scatter was 810 km, and the majority of measurements for the column within it had precisions between 0.2 and 0.9 ppm.

Nitrous Oxide (N2O) Emissions from California based on 2010 CalNex Airborne Measurements

NASA Astrophysics Data System (ADS)

Xiang, B.; Miller, S.; Kort, E. A.; Santoni, G. W.; Daube, B.; Commane, R.; Angevine, W. M.; Ryerson, T. B.; Trainer, M.; Andrews, A. E.; Nehrkorn, T.; Tian, H.; Wofsy, S. C.

2012-12-01

Nitrous oxide (N2O) is an important gas for climate and for stratospheric chemistry, with an atmospheric lifetime exceeding 100 years. Global concentrations have increased steadily since the 18th century, apparently due to human-associated emissions, principally from application of nitrogen fertilizers. However, quantitative studies of agricultural emissions at large spatial scales are lacking, inhibited by the difficulty of measuring small enhancements of atmospheric concentrations. Here we derive regional emission rates for N2O in the Central Valley of California, based on analysis of in-situ airborne atmospheric observations collected using a quantum cascade laser spectrometer. The data were obtained on board the NOAA P-3 research aircraft during the CalNex (California Research at the Nexus of Air Quality and Climate Change) program in May and June, 2010. We coupled WRF (Weather Research and Forecasting) model to STILT (Stochastic Time-Inverted Lagrangian Transport) to link our in-situ observations to surface emissions, and then used a variety of statistical methods to identify source areas and to extract optimized emission rates from the inversion. Our results support the view that fertilizer application is the largest source of N2O in the Central Valley. But the spatial distribution of derived surface emissions, based on California land use and activity maps, was very different than indicated in the leading emissions inventory (EDGAR 4.0), and our estimated total emission flux of N2O for California during the study period was 3 - 4 times larger than EDGAR and other inventories.

Influence of aerosol chemical composition on N2O5 uptake: airborne regional measurements in northwestern Europe

NASA Astrophysics Data System (ADS)

Morgan, W. T.; Ouyang, B.; Allan, J. D.; Aruffo, E.; Di Carlo, P.; Kennedy, O. J.; Lowe, D.; Flynn, M. J.; Rosenberg, P. D.; Williams, P. I.; Jones, R.; McFiggans, G. B.; Coe, H.

2015-01-01

Aerosol chemical composition was found to influence nighttime atmospheric chemistry during a series of airborne measurements in northwestern Europe in summer conditions, which has implications for regional air quality and climate. The uptake of dinitrogen pentoxide, γ (N2O5), to particle surfaces was found to be modulated by the amount of water content and ammonium nitrate present in the aerosol. The conditions prevalent in this study suggest that the net uptake rate of N2O5 to atmospheric aerosols was relatively efficient compared to previous studies, with γ (N2O5) values in the range 0.01-0.03. This is likely a consequence of the elevated relative humidity in the region, which promotes greater aerosol water content. Increased nitrate concentrations relative to particulate water were found to suppress N2O5 uptake. The results presented here contrast with previous ambient studies of N2O5 uptake, which have generally taken place in low-nitrate environments in the USA. Comparison of the N2O5 uptake derived from the measurements with a parameterised scheme that is based on the ratio of particulate water to nitrate yielded reasonably good agreement in terms of the magnitude and variation in uptake, provided the effect of chloride was neglected. An additional suppression of the parameterised uptake is likely required to fully capture the variation in N2O5 uptake, which could be achieved via the known suppression by organic aerosol. However, existing parameterisations representing the suppression by organic aerosol were unable to fully represent the variation in N2O5 uptake. These results provide important ambient measurement constraint on our ability to predict N2O5 uptake in regional and global aerosol models. N2O5 uptake is a potentially important source of nitrate aerosol and a sink of the nitrate radical, which is the main nocturnal oxidant in the atmosphere. The results further highlight the importance of ammonium nitrate in northwestern Europe as a key component

An investigation of airborne allergenic pollen at different heights.

PubMed

Xiao, Xiaojun; Fu, Aixiang; Xie, Xiongjie; Kang, Minxiong; Hu, Dongsheng; Yang, Pingchang; Liu, Zhigang

2013-01-01

Airborne pollen is an important source of allergens in a number of allergic diseases. Data on the concentrations of pollen at different heights in the air are scarce. The aim of the present study was to investigate different types and numbers of airborne pollen and their seasonal variation at different heights in the urban area of Shenzhen (China) and their associations with meteorological factors. The concentration of airborne pollen at different heights was monitored with Burkard traps from July 1, 2006, to June 30, 2007, in Shenzhen; the results were analyzed with SAS 9.13 software. In total, 1,095 films (at 3 heights, 365 films at each height) were exposed throughout the year, and 48 families and 85 genera of pollen taxa were identified. The total pollen count was 55,830 grains (25,204 grains at 1.5 m; 16,218 grains at 35 m, and 14,408 grains at 70 m); pollen grains were present in the atmosphere throughout the year, with two peaks of airborne pollen: one peak in February to April and the other in September to November. On the basis of our local investigations, the pollen concentrations and the pollen types in the air decrease gradually with increasing height. The distribution and concentrations of airborne pollen at different heights in the atmosphere were influenced by composite factors such as the season and meteorological factors. Copyright © 2012 S. Karger AG, Basel.

Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) Instrument Improvements

NASA Technical Reports Server (NTRS)

Dunagan, Stephen E.; Redemann, Jens; Chang, Cecilia; Dahlgren, Robert; Fahey, Lauren; Flynn, Connor; Johnson, Roy; Kacenelenbogen, Meloe; Leblanc, Samuel; Liss, Jordan;

Transmission of Airborne Bacteria across Built Environments and Its Measurement Standards: A Review.

PubMed

Fujiyoshi, So; Tanaka, Daisuke; Maruyama, Fumito

2017-01-01

Human health is influenced by various factors including microorganisms present in built environments where people spend most of their lives (approximately 90%). It is therefore necessary to monitor and control indoor airborne microbes for occupational safety and public health. Most studies concerning airborne microorganisms have focused on fungi, with scant data available concerning bacteria. The present review considers papers published from 2010 to 2017 approximately and factors affecting properties of indoor airborne bacteria (communities and concentration) with respect to temporal perspective and to multiscale interaction viewpoint. From a temporal perspective, bacterial concentrations in built environments change depending on numbers of human occupancy, while properties of bacterial communities tend to remain stable. Similarly, the bacteria found in social and community spaces such as offices, classrooms and hospitals are mainly associated with human occupancy. Other major sources of indoor airborne bacteria are (i) outdoor environments, and (ii) the building materials themselves. Indoor bacterial communities and concentrations are varied with varying interferences by outdoor environment. Airborne bacteria from the outdoor environment enter an indoor space through open doors and windows, while indoor bacteria are simultaneously released to the outer environment. Outdoor bacterial communities and their concentrations are also affected by geographical factors such as types of land use and their spatial distribution. The bacteria found in built environments therefore originate from any of the natural and man-made surroundings around humans. Therefore, to better understand the factors influencing bacterial concentrations and communities in built environments, we should study all the environments that humans contact as a single ecosystem. In this review, we propose the establishment of a standard procedure for assessing properties of indoor airborne bacteria using

Transmission of Airborne Bacteria across Built Environments and Its Measurement Standards: A Review

PubMed Central

Fujiyoshi, So; Tanaka, Daisuke; Maruyama, Fumito

2017-01-01

Human health is influenced by various factors including microorganisms present in built environments where people spend most of their lives (approximately 90%). It is therefore necessary to monitor and control indoor airborne microbes for occupational safety and public health. Most studies concerning airborne microorganisms have focused on fungi, with scant data available concerning bacteria. The present review considers papers published from 2010 to 2017 approximately and factors affecting properties of indoor airborne bacteria (communities and concentration) with respect to temporal perspective and to multiscale interaction viewpoint. From a temporal perspective, bacterial concentrations in built environments change depending on numbers of human occupancy, while properties of bacterial communities tend to remain stable. Similarly, the bacteria found in social and community spaces such as offices, classrooms and hospitals are mainly associated with human occupancy. Other major sources of indoor airborne bacteria are (i) outdoor environments, and (ii) the building materials themselves. Indoor bacterial communities and concentrations are varied with varying interferences by outdoor environment. Airborne bacteria from the outdoor environment enter an indoor space through open doors and windows, while indoor bacteria are simultaneously released to the outer environment. Outdoor bacterial communities and their concentrations are also affected by geographical factors such as types of land use and their spatial distribution. The bacteria found in built environments therefore originate from any of the natural and man-made surroundings around humans. Therefore, to better understand the factors influencing bacterial concentrations and communities in built environments, we should study all the environments that humans contact as a single ecosystem. In this review, we propose the establishment of a standard procedure for assessing properties of indoor airborne bacteria using

Airborne Laser CO2 Column Measurements: Evaluation of Precision and Accuracy Under a Wide Range of Surface and Atmospheric Conditions

NASA Astrophysics Data System (ADS)

Browell, E. V.; Dobler, J. T.; Kooi, S. A.; Fenn, M. A.; Choi, Y.; Vay, S. A.; Harrison, F. W.; Moore, B.

2011-12-01

This paper discusses the latest flight test results of a multi-frequency intensity-modulated (IM) continuous-wave (CW) laser absorption spectrometer (LAS) that operates near 1.57 μm for remote CO2 column measurements. This IM-LAS system is under development for a future space-based mission to determine the global distribution of regional-scale CO2 sources and sinks, which is the objective of the NASA Active Sensing of CO2 Emissions during Nights, Days, and Seasons (ASCENDS) mission. A prototype of the ASCENDS system, called the Multi-frequency Fiber Laser Lidar (MFLL), has been flight tested in eleven airborne campaigns since May 2005. This paper compares the most recent results obtained during the 2010 and 2011 UC-12 and DC-8 flight tests, where MFLL remote CO2 column measurements were evaluated against airborne in situ CO2 profile measurements traceable to World Meteorological Organization standards. The major change to the MFLL system in 2011 was the implementation of several different IM modes, which could be quickly changed in flight, to directly compare the precision and accuracy of MFLL CO2 measurements in each mode. The different IM modes that were evaluated included "fixed" IM frequencies near 50, 200, and 500 kHz; frequencies changed in short time steps (Stepped); continuously swept frequencies (Swept); and a pseudo noise (PN) code. The Stepped, Swept, and PN modes were generated to evaluate the ability of these IM modes to desensitize MFLL CO2 column measurements to intervening optically thin aerosols/clouds. MFLL was flown on the NASA Langley UC-12 aircraft in May 2011 to evaluate the newly implemented IM modes and their impact on CO2 measurement precision and accuracy, and to determine which IM mode provided the greatest thin cloud rejection (TCR) for the CO2 column measurements. Within the current hardware limitations of the MFLL system, the "fixed" 50 kHz results produced similar SNR values to those found previously. The SNR decreased as expected

Airborne organophosphate pesticides drift in Mediterranean climate: The importance of secondary drift

NASA Astrophysics Data System (ADS)

Zivan, Ohad; Segal-Rosenheimer, Michal; Dubowski, Yael

2016-02-01

Pesticide application is a short-term air-pollution episode with near and far field effects due to atmospheric drift. In order to better evaluate resulting air concentrations in nearby communities following pesticide application, measurements of airborne pesticides were conducted at ∼70 m from field edge. This was done following three different application events of the organophosphate pesticide Chlorpyrifos in a persimmon orchard. Complementary information on larger spatial scale was obtained using CALPUFF modeling in which application and meteorological data was used to better evaluate dispersion patterns. Measurements indicated high airborne concentrations during application hours (few μg m-3 for 8 h average), which dropped to tens of ng m-3 in the following days. Measured atmospheric concentrations show that secondary drift (i.e., post-application drift) involves significant loads of pesticides and hence should not be ignored in exposure considerations. Furthermore, CALPUFF modeling revealed the complex dispersion pattern when weak winds prevailed, and showed that during the 24 h after application air concentrations reached levels above the hourly Texas effect screening level (0.1 μg m-3). Interestingly, weak winds on the night after application resulted in a secondary peak in measured and modeled air concentrations. Long exposure time (when secondary drift is considered) and concentrations measured following such common air-assisted orchard application, suggest pesticide drift may have health repercussions that are currently unknown, and emphasize the need for further epidemiological studies.

Airborne Tropical TRopopause EXperiment (ATTREX) 2014 Western Pacific Campaign

NASA Technical Reports Server (NTRS)

Jensen, E.; Pfister, L.

2014-01-01

The NASA Airborne Tropical TRopopause EXperiment (ATTREX) is a series of airborne campaigns focused on understanding physical processes in the Tropical Tropopause Layer (TTL) and their role in atmospheric chemistry and climate. ATTREX is using the high-altitude, long-duration NASA Global Hawk Unmanned Air System to make in situ and remote-sensing measurements spanning the Pacific. A particular ATTREX emphasis is to better understand the dehydration of air as it passes through the cold tropical tropopause region. The ATTREX payload contains 12 in situ and remote sensing instruments that measure water vapor, carbon dioxide, methane, nonmethane hydrocarbons, sulfur hexafluoride, chlorofluorocarbons, nitrous oxide), reactive chemical compounds (ozone, bromine, nitrous oxide), meteorological parameters, and radiative fluxes. During January-March, 2014, the Global Hawk was deployed to Guam for ATTREX flights. Six science flights were conducted from Guam (in addition to the transits across the Pacific), resulting in over 100 hours of Western Pacific TTL sampling and about 180 vertical profiles through the TTL. I will provide an overview of the dataset, with examples of the measurements including meteorological parameters, clouds and water vapor, and chemical tracers.

Airborne in situ vertical profiling of HDO / H216O in the subtropical troposphere during the MUSICA remote sensing validation campaign

NASA Astrophysics Data System (ADS)

Dyroff, C.; Sanati, S.; Christner, E.; Zahn, A.; Balzer, M.; Bouquet, H.; McManus, J. B.; Gonzalez-Ramos, Y.; Schneider, M.

2015-05-01

Vertical profiles of water vapor (H2O) and its isotope ratio D / H expressed as δD(H2O) were measured in situ by the ISOWAT II diode-laser spectrometer during the MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water (MUSICA) airborne campaign. We present recent modifications of the instrument design. The instrument calibration on the ground as well as in flight is described. Based on the calibration measurements, the humidity-dependent uncertainty of our airborne data is determined. For the majority of the airborne data we achieved an accuracy (uncertainty of the mean) of Δ(δD) ≈10‰. Vertical profiles between 150 and ~7000 m were obtained during 7 days in July and August 2013 over the subtropical North Atlantic Ocean near Tenerife. The flights were coordinated with ground-based (Network for the Detection of Atmospheric Composition Change, NDACC) and space-based (Infrared Atmospheric Sounding Interferometer, IASI) FTIR remote sensing measurements of δD(H2O) as a means to validate the remote sensing humidity and δD(H2O) data products. The results of the validation are presented in detail in a separate paper (Schneider et al., 2014). The profiles were obtained with a high vertical resolution of around 3 m. By analyzing humidity and δD(H2O) correlations we were able to identify different layers of air masses with specific isotopic signatures. The results are discussed.

Airborne in situ vertical profiling of HDO/H216O in the subtropical troposphere during the MUSICA remote sensing validation campaign

NASA Astrophysics Data System (ADS)

Dyroff, C.; Sanati, S.; Christner, E.; Zahn, A.; Balzer, M.; Bouquet, H.; McManus, J. B.; González-Ramos, Y.; Schneider, M.

2015-01-01

Vertical profiles of water vapor (H2O) and its isotope ratio D / H expressed as δ D(H2O were measured in situ by the ISOWAT II diode-laser spectrometer during the MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water (MUSICA) airborne campaign. We present recent modifications of the instrument design. The instrument calibration on the ground as well as in flight is described. Based on the calibration measurements, the humidity-dependent uncertainty of our airborne data is determined. For the majority of the airborne data we achieved an accuracy (uncertainty of the mean) of Δ(δ D) ≈ 10‰. Vertical profiles between 150 and ~7000 m were obtained during 7 days in July and August 2013 over the subtropical North Atlantic Ocean near Tenerife. The flights were coordinated with ground-based (Network for the Detection of Atmospheric Composition Change, NDACC) and space-based (Infrared Atmospheric Sounding Interferometer, IASI) FTIR remote-sensing measurements of δ D(H2O) as a means to validate the remote sensing humidity and δ D(H2O) data products. The results of the validation are presented in detail in a separate paper (Schneider et al., 2014). The profiles were obtained with a high vertical resolution of around 3 m. By analyzing humidity and δ D(H2O) correlations we were able to identify different layers of airmasses with specific isotopic signatures. The results are discussed.

Satellite and airborne IR sensor validation by an airborne interferometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gumley, L.E.; Delst, P.F. van; Moeller, C.C.

1996-11-01

The validation of in-orbit longwave IR radiances from the GOES-8 Sounder and inflight longwave IR radiances from the MODIS Airborne Simulator (MAS) is described. The reference used is the airborne University of Wisconsin High Resolution Interferometer Sounder (HIS). The calibration of each sensor is described. Data collected during the Ocean Temperature Interferometric Survey (OTIS) experiment in January 1995 is used in the comparison between sensors. Detailed forward calculations of at-sensor radiance are used to account for the difference in GOES-8 and HIS altitude and viewing geometry. MAS radiances and spectrally averaged HIS radiances are compared directly. Differences between GOES-8 andmore » HIS brightness temperatures, and GOES-8 and MAS brightness temperatures, are found to be with 1.0 K for the majority of longwave channels examined. The same validation approach will be used for future sensors such as the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Atmospheric Infrared Sounder (AIRS). 11 refs., 2 figs., 4 tabs.« less

Analyzing carbon dioxide and methane emissions in California using airborne measurements and model simulations

NASA Astrophysics Data System (ADS)

Johnson, M. S.; Yates, E. L.; Iraci, L. T.; Jeong, S.; Fischer, M. L.

2013-12-01

Greenhouse gas (GHG) concentrations have increased over the past decades and are linked to global temperature increases and climate change. These changes in climate have been suggested to have varying effects, and uncertain consequences, on agriculture, water supply, weather, sea-level rise, the economy, and energy. To counteract the trend of increasing atmospheric concentrations of GHGs, the state of California has passed the California Global Warming Act of 2006 (AB-32). This requires that by the year 2020, GHG (e.g., carbon dioxide (CO2) and methane (CH4)) emissions will be reduced to 1990 levels. To quantify GHG fluxes, emission inventories are routinely compiled for the State of California (e.g., CH4 emissions from the California Greenhouse Gas Emissions Measurement (CALGEM) Project). The major sources of CO2 and CH4 in the state of California are: transportation, electricity production, oil and gas extraction, cement plants, agriculture, landfills/waste, livestock, and wetlands. However, uncertainties remain in these emission inventories because many factors contributing to these processes are poorly quantified. To alleviate these uncertainties, a synergistic approach of applying air-borne measurements and chemical transport modeling (CTM) efforts to provide a method of quantifying local and regional GHG emissions will be performed during this study. Additionally, in order to further understand the temporal and spatial distributions of GHG fluxes in California and the impact these species have on regional climate, CTM simulations of daily variations and seasonality of total column CO2 and CH4 will be analyzed. To assess the magnitude and spatial variation of GHG emissions and to identify local 'hot spots', airborne measurements of CH4 and CO2 were made by the Alpha Jet Atmospheric eXperiment (AJAX) over the San Francisco Bay Area (SFBA) and San Joaquin Valley (SJV) in January and February 2013 during the Discover-AQ-CA study. High mixing ratios of GHGs were

First Airborne IPDA Lidar Measurements of Methane and Carbon Dioxide Applying the DLR Greenhouse Gas Sounder CHARM-F

NASA Astrophysics Data System (ADS)

Amediek, A.; Ehret, G.; Fix, A.; Wirth, M.; Quatrevalet, M.; Büdenbender, C.; Kiemle, C.; Loehring, J.; Gerbig, C.

2015-12-01

First airborne measurement using CHARM-F, the four-wavelengths lidar for simultaneous soundings of atmospheric CO2 and CH4, were performed in Spring 2015 onboard the German research aircraft HALO. The lidar is designed in the IPDA (integrated path differential absorption) configuration using short double pulses, which gives column averaged gas mixing ratios between aircraft and ground. HALO's maximum flight altitude of 15 km and special features of the lidar, such as a relatively large laser ground spot, enable the CHARM-F system to be an airborne demonstrator for future spaceborne greenhouse gas lidars. Due to a high technological conformity this applies in particular to the French-German satellite mission MERLIN, the spaceborne methane IPDA lidar. The successfully completed flight measurements provide a valuable dataset, which supports the retrieval algorithm development for MERLIN notably. The flights covered different ground cover types, different orography types as well as the sea. Additionally, we captured different cloud conditions, at which the broken cloud case is a matter of particular interest. This dataset allows detailed analyses of measurement sensitivities, general studies on the IPDA principle and on technical details of the system. These activities are supported by another instrument onboard: a cavity ring down spectrometer, providing in-situ data of carbon dioxide, methane and water vapor with high accuracy and precision, which is ideal for validation purposes of the lidar. Additionally the onboard instrumentation of HALO gives information about pressure and temperature for cross-checking the ECMWF data, which are intended to be used for calculating the weighting function, the key quantity for the retrieval of gas column mixing ratios from the measured gas optical depths. In combination with dedicated descents into the boundary layer and subsequent ascents, a self-contained dataset for characterizations of CHARM-F is available.

MicroMED: a dust particle counter for the characterization of airborne dust close to the surface of Mars

NASA Astrophysics Data System (ADS)

Cozzolino, Fabio; Esposito, Francesca; Molfese, Cesare; Cortecchia, Fausto; Saggin, Bortolino; D'amato, Francesco

2015-04-01

Monitoring of airborne dust is very important in planetary climatology. Indeed, dust absorbs and scatter solar and thermal radiation, severely affecting atmospheric thermal structure, balance and dynamics (in terms of circulations). Wind-driven blowing of sand and dust is also responsible for shaping planetary surfaces through the formation of sand dunes and ripples, the erosion of rocks, and the creation and transport of soil particles. Dust is permanently present in the atmosphere of Mars and its amount varies with seasons. During regional or global dust storms, more than 80% of the incoming sunlight is absorbed by dust causing an intense atmospheric heating. Airborne dust is therefore a crucial climate component on Mars which impacts atmospheric circulations at all scales. Main dust parameters influencing the atmosphere heating are size distribution, abundance, albedo, single scattering phase function, imaginary part of the index of refraction. Moreover, major improvements of Mars climate models require, in addition to the standard meteorological parameters, quantitative information about dust lifting, transport and removal mechanisms. In this context, two major quantities need to be measured for the dust source to be understood: surface flux and granulometry. While many observations have constrained the size distribution of the dust haze seen from the orbit, it is still not known what the primary airborne dust (e.g. the recently lifted dust) is made of, size-wise. MicroMED has been designed to fill this gap. It will measure the abundance and size distribution of dust, not in the atmospheric column, but close to the surface, where dust is lifted, so to be able to monitor dust injection into the atmosphere. This has never been performed in Mars and other planets exploration. MicroMED is an Optical Particle Counter, analyzing light scattered from single dust particles to measure their size and abundance. A proper fluid-dynamic system, including a pump and a

Airborne lidar mapping of vertical ozone distributions in support of the 1990 Clean Air Act Amendments

NASA Technical Reports Server (NTRS)

Uthe, Edward E.; Nielsen, Norman B.; Livingston, John M.

1992-01-01

The 1990 Clean Air Act Amendments mandated attainment of the ozone standard established by the U.S. Environmental Protection Agency. Improved photochemical models validated by experimental data are needed to develop strategies for reducing near surface ozone concentrations downwind of urban and industrial centers. For more than 10 years, lidar has been used on large aircraft to provide unique information on ozone distributions in the atmosphere. However, compact airborne lidar systems are needed for operation on small aircraft of the type typically used on regional air quality investigations to collect data with which to develop and validate air quality models. Data presented in this paper will consist of a comparison between airborne differential absorption lidar (DIAL) and airborne in-situ ozone measurements. Also discussed are future plans to improve the airborne ultraviolet-DIAL for ozone and other gas observations and addition of a Fourier Transform Infrared (FTIR) emission spectrometer to investigate the effects of other gas species on vertical ozone distribution.

COMET: a planned airborne mission to simultaneously measure CO2 and CH4 columns using airborne remote sensing and in-situ techniques

NASA Astrophysics Data System (ADS)

Fix, A.; Amediek, A.; Büdenbender, C.; Ehret, G.; Wirth, M.; Quatrevalet, M.; Rapp, M.; Gerilowski, K.; Bovensmann, H.; Gerbig, C.; Pfeilsticker, K.; Zöger, M.; Giez, A.

2013-12-01

To better predict future trends in the cycles of the most important anthropogenic greenhouse gases, CO2 and CH4, there is a need to measure and understand their distribution and variation on various scales. To address these requirements it is envisaged to deploy a suite of state-of-the-art airborne instruments that will be capable to simultaneously measure the column averaged dry-air mixing ratios (XGHG) of both greenhouse gases along the flight path. As the measurement platform serves the research aircraft HALO, a modified Gulfstream G550, operated by DLR. This activity is dubbed CoMet (CO2 and Methane Mission). The instrument package of CoMet will consist of active and passive remote sensors as well as in-situ instruments to complement the column measurements by highly-resolved profile information. As an active remote sensing instrument CHARM-F, the integrated-path differential absorption lidar currently under development at DLR, will provide both, XCO2 and XCH4, below flight altitude. The lidar instrument will be complemented by MAMAP which is a NIR/SWIR absorption spectrometer developed by University of Bremen and which is also capable to derive XCH4 and XCO2. As an additional passive instrument, mini-DOAS operated by University of Heidelberg will contribute with additional context information about the investigated air masses. In order to compare the remote sensing instruments with integrated profile information, in-situ instrumentation is indispensable. The in-situ package will therefore comprise wavelength-scanned Cavity-Ring-Down Spectroscopy (CRDS) for the detection of CO2, CH4, CO and H2O and a flask sampler for collection of atmospheric samples and subsequent laboratory analysis. Furthermore, the BAsic HALO Measurement And Sensor System (BAHAMAS) will provide an accurate set of meteorological and aircraft state parameters for each scientific flight. Within the frame of the first CoMet mission scheduled for the 2015 timeframe it is planned to concentrate

Airborne Sunphotometer Measurements of Aerosol Optical Depth and Water Vapor in ACE-Asia and Their Comparisons to Correlative Measurements

NASA Technical Reports Server (NTRS)

Schmid, B.; Redemann, J.; Livingston, J.; Russell, P.; Hegg, D.; Wang, J.; Kahn, R.; Hsu, C.; Masonis, S.; Murayama, T.;

Active optical CO2 sensing for Ground-based, Airborne, and from Space platform

NASA Astrophysics Data System (ADS)

Sakaizawa, D.; Kawakami, S.; Nakajima, M.; Tanaka, T.; Miyamoto, Y.; Inoue, M.; Morino, I.; Uchino, O.; Sawa, Y.; Matsueda, H.

2011-12-01

Accurate measurements of lower tropospheric CO2 from space are strongly needed to quantify processes that identify the CO2 flux by the lands and oceans. The Greenhouse gases Observing SATellite (GOSAT) is the first space mission focused on lower tropospheric CO2 measurements by detecting the near-infrared spectral absorption in reflected sunlight. The GOSAT mission is a key first step, and will increase knowledge about atmospheric CO2 distributions. However there are unavoidable limitations imposed by its measurements approach, 1) the best performance of CO2 total column measurements can only be performed under the clear-sky atmosphere, 2) seasonal dependence reduces its global coverage, such as the case of the northern hemisphere in winter, and 3) unknowns and variations in cloud and aerosol contamination is also sensitive for CO2 measurements. The laser-based CO2 remote sensing is advantage of those un-met needs. We have developed and improved a compact differential laser absorption sensor (LAS) for measuring the weighted column-averaged dry CO2 mixing ratio (Wq) as a candidate for space mission. Our instrument employs two continuous-wave lasers and a fiber amplifier, which are available of simultaneous measurements of CO2 differential absorption optical depth and range to the target. The amplitude-modulated laser outputs are amplified by a fiber-amplifier. The receiver uses a compact telescope and photodiodes, and measures the laser powers reflected from the target. The gas absorption and column-averaged mixing ratio for the CO2 are evaluated from the ratio of the on- and off-line signals. We have performed ground-based and airborne measurement to evaluate uncertainty of Wq measurements. In these measurements R(12) line in the (30012<-00001) absorption bands of 12C16O2 was used. The precision of the ground-based measurements of horizontal Wq was 0.49% for a horizontal range of 2.1 km. The first airborne measurements were also made during August 2009. These

Atmospheric transformation of solar radiation reflected from the ocean

NASA Technical Reports Server (NTRS)

Malkevich, M. S.; Istomina, L. G.; Hovis, W. A., Jr.

1977-01-01

Airborne measurements of the brightness spectrum of the Atlantic Ocean in the wavelength region from 0.4 to 0.7 micron are analyzed. These measurements were made over a tropical region of the Atlantic from an aircraft at heights of 0.3 and 10.5 km during the TROPEX-72 experiment. The results are used to estimate the contribution of the atmosphere to the overall brightness of the ocean-atmosphere system. It is concluded that: (1) the atmosphere decreases the absolute brightness of the ocean by a factor of 5 to 10 and also strongly affects the spectral behavior of solar radiation reflected from the ocean surface; (2) the atmospheric contribution to overall brightness may vary considerably under real conditions; (3) finely dispersed particles and Rayleigh scattering affect the spectral distribution of solar radiation; and (4) the spectral composition of ocean-atmosphere brightness may be completely governed by the atmosphere.

Evaluation of the reactive nitrogen budget of the remote atmosphere in global models using airborne measurements

NASA Astrophysics Data System (ADS)

Murray, L. T.; Strode, S. A.; Fiore, A. M.; Lamarque, J. F.; Prather, M. J.; Thompson, C. R.; Peischl, J.; Ryerson, T. B.; Allen, H.; Blake, D. R.; Crounse, J. D.; Brune, W. H.; Elkins, J. W.; Hall, S. R.; Hintsa, E. J.; Huey, L. G.; Kim, M. J.; Moore, F. L.; Ullmann, K.; Wennberg, P. O.; Wofsy, S. C.

2017-12-01

Nitrogen oxides (NOx ≡ NO + NO2) in the background atmosphere are critical precursors for the formation of tropospheric ozone and OH, thereby exerting strong influence on surface air quality, reactive greenhouse gases, and ecosystem health. The impact of NOx on atmospheric composition and climate is sensitive to the relative partitioning of reactive nitrogen between NOx and longer-lived reservoir species of the total reactive nitrogen family (NOy) such as HNO3, HNO4, PAN and organic nitrates (RONO2). Unfortunately, global chemistry-climate models (CCMs) and chemistry-transport models (CTMs) have historically disagreed in their reactive nitrogen budgets outside of polluted continental regions, and we have lacked in situ observations with which to evaluate them. Here, we compare and evaluate the NOy budget of six global models (GEOS-Chem CTM, GFDL AM3 CCM, GISS E2.1 CCM, GMI CTM, NCAR CAM CCM, and UCI CTM) using new observations of total reactive nitrogen and its member species from the NASA Atmospheric Tomography (ATom) mission. ATom has now completed two of its four planned deployments sampling the remote Pacific and Atlantic basins of both hemispheres with a comprehensive suite of measurements for constraining reactive photochemistry. All six models have simulated conditions climatologically similar to the deployments. The GMI and GEOS-Chem CTMs have in addition performed hindcast simulations using the MERRA-2 reanalysis, and have been sampled along the flight tracks. We evaluate the performance of the models relative to the observations, and identify factors contributing to their disparate behavior using known differences in model oxidation mechanisms, heterogeneous loss pathways, lightning and surface emissions, and physical loss processes.

Source Term Estimation of Radioxenon Released from the Fukushima Dai-ichi Nuclear Reactors Using Measured Air Concentrations and Atmospheric Transport Modeling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eslinger, Paul W.; Biegalski, S.; Bowyer, Ted W.

2014-01-01

Systems designed to monitor airborne radionuclides released from underground nuclear explosions detected radioactive fallout from the Fukushima Daiichi nuclear accident in March 2011. Atmospheric transport modeling (ATM) of plumes of noble gases and particulates were performed soon after the accident to determine plausible detection locations of any radioactive releases to the atmosphere. We combine sampling data from multiple International Modeling System (IMS) locations in a new way to estimate the magnitude and time sequence of the releases. Dilution factors from the modeled plume at five different detection locations were combined with 57 atmospheric concentration measurements of 133-Xe taken from Marchmore » 18 to March 23 to estimate the source term. This approach estimates that 59% of the 1.24×1019 Bq of 133-Xe present in the reactors at the time of the earthquake was released to the atmosphere over a three day period. Source term estimates from combinations of detection sites have lower spread than estimates based on measurements at single detection sites. Sensitivity cases based on data from four or more detection locations bound the source term between 35% and 255% of available xenon inventory.« less

Release of Airborne Polychlorinated Biphenyls from New Bedford Harbor Results in Elevated Concentrations in the Surrounding Air.

PubMed

Martinez, Andres; Hadnott, Bailey N; Awad, Andrew M; Herkert, Nicholas J; Tomsho, Kathryn; Basra, Komal; Scammell, Madeleine K; Heiger-Bernays, Wendy; Hornbuckle, Keri C

2017-04-11

Qualitatively and quantitatively, we have demonstrated that airborne polychlorinated biphenyl (PCB) concentrations in the air surrounding New Bedford Harbor (NBH) are caused by its water PCB emissions. We measured airborne PCBs at 18 homes and businesses near NBH in 2015, with values ranging from 0.4 to 38 ng m -3 , with a very strong Aroclor 1242/1016 signal that is most pronounced closest to the harbor and reproducible over three sampling rounds. Using U.S. Environmental Protection Agency (U.S. EPA) water PCB data from 2015 and local meteorology, we predicted gas-phase fluxes of PCBs from 160 to 1200 μg m -2 day -1 . Fluxes were used as emissions for AERMOD, a widely applied U.S. EPA atmospheric dispersion model, to predict airborne PCB concentrations. The AERMOD predictions were within a factor of 2 of the field measurements. PCB emission from NBH (110 kg year -1 , average 2015) is the largest reported source of airborne PCBs from natural waters in North America, and the source of high ambient air PCB concentrations in locations close to NBH. It is likely that NBH has been an important source of airborne PCBs since it was contaminated with Aroclors more than 60 years ago.

NASA Standard for Airborne Data: ICARTT Format ESDS-RFC-019

NASA Astrophysics Data System (ADS)

Thornhill, A.; Brown, C.; Aknan, A.; Crawford, J. H.; Chen, G.; Williams, E. J.

2011-12-01

Airborne field studies generate a plethora of data products in the effort to study atmospheric composition and processes. Data file formats for airborne field campaigns are designed to present data in an understandable and organized way to support collaboration and to document relevant and important meta data. The ICARTT file format was created to facilitate data management during the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) campaign in 2004 that involved government-agencies and university participants from five countries. Since this mission the ICARTT format has been used in subsequent field campaigns such as Polar Study Using Aircraft Remote Sensing, Surface Measurements and Models of Climates, Chemistry, Aerosols, and Transport (POLARCAT) and the first phase of Deriving Information on Surface Conditions from COlumn and VERtically Resolved Observations Relevant to Air Quality (DISCOVER-AQ). The ICARTT file format has been endorsed as a standard format for airborne data by the Standard Process Group (SPG), one of the Earth Science Data Systems Working Groups (ESDSWG) in 2010. The detailed description of the ICARTT format can be found at http://www-air.larc.nasa.gov/missions/etc/ESDS-RFC-019-v1.00.pdf. The ICARTT data format is an ASCII, comma delimited format that was based on the NASA Ames and GTE file formats. The file header is detailed enough to fully describe the data for users outside of the instrument group and includes a description of the meta data. The ICARTT scanning tools, format structure, implementations, and examples will be presented.

The Next Generation of Airborne Polarimetric Doppler Weather Radar: NCAR/EOL Airborne Phased Array Radar (APAR) Development

NASA Astrophysics Data System (ADS)

Moore, James; Lee, Wen-Chau; Loew, Eric; Vivekanandan, Jothiram; Grubišić, Vanda; Tsai, Peisang; Dixon, Mike; Emmett, Jonathan; Lord, Mark; Lussier, Louis; Hwang, Kyuil; Ranson, James

2017-04-01

The National Center for Atmospheric Research (NCAR) Earth observing Laboratory (EOL) is entering the third year of preliminary system design studies, engineering prototype testing and project management plan preparation for the development of a novel Airborne Phased Array Radar (APAR). This system being designed by NCAR/EOL will be installed and operated on the NSF/NCAR C-130 aircraft. The APAR system will consist of four removable C-band Active Electronically Scanned Arrays (AESA) strategically placed on the fuselage of the aircraft. Each AESA measures approximately 1.5 x 1.9 m and is composed of 3000 active radiating elements arranged in an array of line replaceable units (LRU) to simplify maintenance. APAR will provide unprecedented observations, and in conjunction with the advanced radar data assimilation schema, will be able to address the key science questions to improve understanding and predictability of significant and high-impact weather APAR, operating at C-band, allows the measurement of 3-D kinematics of the more intense portions of storms (e.g. thunderstorm dynamics and tornadic development, tropical cyclone rainband structure and evolution) with less attenuation compared with current airborne Doppler radar systems. Polarimetric measurements are not available from current airborne tail Doppler radars. However, APAR, with dual-Doppler and dual polarization diversity at a lesser attenuating C-band wavelength, will further advance the understanding of the microphysical processes within a variety of precipitation systems. The radar is sensitive enough to provide high resolution measurements of winter storm dynamics and microphysics. The planned APAR development that would bring the system to operational readiness for research community use aboard the C-130 is expected to take 8 years once major funding support is realized. The authors will review the overall APAR design and provide new details of the system based on our Technical Requirements Document

An Overview of the Regional Experiments for Land-atmosphere Exchanges 2012 (REFLEX 2012) Campaign

NASA Astrophysics Data System (ADS)

Timmermans, Wim J.; van der Tol, Christiaan; Timmermans, Joris; Ucer, Murat; Chen, Xuelong; Alonso, Luis; Moreno, Jose; Carrara, Arnaud; Lopez, Ramon; de la Cruz Tercero, Fernando; Corcoles, Horacio L.; de Miguel, Eduardo; Sanchez, Jose A. G.; Pérez, Irene; Franch, Belen; Munoz, Juan-Carlos J.; Skokovic, Drazen; Sobrino, Jose; Soria, Guillem; MacArthur, Alasdair; Vescovo, Loris; Reusen, Ils; Andreu, Ana; Burkart, Andreas; Cilia, Chiara; Contreras, Sergio; Corbari, Chiara; Calleja, Javier F.; Guzinski, Radoslaw; Hellmann, Christine; Herrmann, Ittai; Kerr, Gregoire; Lazar, Adina-Laura; Leutner, Benjamin; Mendiguren, Gorka; Nasilowska, Sylwia; Nieto, Hector; Pachego-Labrador, Javier; Pulanekar, Survana; Raj, Rahul; Schikling, Anke; Siegmann, Bastian; von Bueren, Stefanie; Su, Zhongbo (Bob)

2015-12-01

The REFLEX 2012 campaign was initiated as part of a training course on the organization of an airborne campaign to support advancement of the understanding of land-atmosphere interaction processes. This article describes the campaign, its objectives and observations, remote as well as in situ. The observations took place at the experimental Las Tiesas farm in an agricultural area in the south of Spain. During the period of ten days, measurements were made to capture the main processes controlling the local and regional land-atmosphere exchanges. Apart from multi-temporal, multi-directional and multi-spatial space-borne and airborne observations, measurements of the local meteorology, energy fluxes, soil temperature profiles, soil moisture profiles, surface temperature, canopy structure as well as leaf-level measurements were carried out. Additional thermo-dynamical monitoring took place at selected sites. After presenting the different types of measurements, some examples are given to illustrate the potential of the observations made.

Validation of Airborne FMCW Radar Measurements of Snow Thickness Over Sea Ice in Antarctica

NASA Technical Reports Server (NTRS)

Galin, Natalia; Worby, Anthony; Markus, Thorsten; Leuschen, Carl; Gogineni, Prasad

2012-01-01

Antarctic sea ice and its snow cover are integral components of the global climate system, yet many aspects of their vertical dimensions are poorly understood, making their representation in global climate models poor. Remote sensing is the key to monitoring the dynamic nature of sea ice and its snow cover. Reliable and accurate snow thickness data are currently a highly sought after data product. Remotely sensed snow thickness measurements can provide an indication of precipitation levels, predicted to increase with effects of climate change in the polar regions. Airborne techniques provide a means for regional-scale estimation of snow depth and distribution. Accurate regional-scale snow thickness data will also facilitate an increase in the accuracy of sea ice thickness retrieval from satellite altimeter freeboard estimates. The airborne data sets are easier to validate with in situ measurements and are better suited to validating satellite algorithms when compared with in situ techniques. This is primarily due to two factors: better chance of getting coincident in situ and airborne data sets and the tractability of comparison between an in situ data set and the airborne data set averaged over the footprint of the antennas. A 28-GHz frequency modulated continuous wave (FMCW) radar loaned by the Center for Remote Sensing of Ice Sheets to the Australian Antarctic Division is used to measure snow thickness over sea ice in East Antarctica. Provided with the radar design parameters, the expected performance parameters of the radar are summarized. The necessary conditions for unambiguous identification of the airsnow and snowice layers for the radar are presented. Roughnesses of the snow and ice surfaces are found to be dominant determinants in the effectiveness of layer identification for this radar. Finally, this paper presents the first in situ validated snow thickness estimates over sea ice in Antarctica derived from an FMCW radar on a helicopterborne platform.

Emerging Technologies and Synergies for Airborne and Space-Based Measurements of Water Vapor Profiles

NASA Astrophysics Data System (ADS)

Nehrir, Amin R.; Kiemle, Christoph; Lebsock, Mathew D.; Kirchengast, Gottfried; Buehler, Stefan A.; Löhnert, Ulrich; Liu, Cong-Liang; Hargrave, Peter C.; Barrera-Verdejo, Maria; Winker, David M.

2017-11-01

A deeper understanding of how clouds will respond to a warming climate is one of the outstanding challenges in climate science. Uncertainties in the response of clouds, and particularly shallow clouds, have been identified as the dominant source of the discrepancy in model estimates of equilibrium climate sensitivity. As the community gains a deeper understanding of the many processes involved, there is a growing appreciation of the critical role played by fluctuations in water vapor and the coupling of water vapor and atmospheric circulations. Reduction of uncertainties in cloud-climate feedbacks and convection initiation as well as improved understanding of processes governing these effects will result from profiling of water vapor in the lower troposphere with improved accuracy and vertical resolution compared to existing airborne and space-based measurements. This paper highlights new technologies and improved measurement approaches for measuring lower tropospheric water vapor and their expected added value to current observations. Those include differential absorption lidar and radar, microwave occultation between low-Earth orbiters, and hyperspectral microwave remote sensing. Each methodology is briefly explained, and measurement capabilities as well as the current technological readiness for aircraft and satellite implementation are specified. Potential synergies between the technologies are discussed, actual examples hereof are given, and future perspectives are explored. Based on technical maturity and the foreseen near-mid-term development path of the various discussed measurement approaches, we find that improved measurements of water vapor throughout the troposphere would greatly benefit from the combination of differential absorption lidar focusing on the lower troposphere with passive remote sensors constraining the upper-tropospheric humidity.

Progress on development of an airborne two-micron IPDA lidar for water vapor and carbon dioxide column measurements

NASA Astrophysics Data System (ADS)

Singh, Upendra N.; Petros, Mulugeta; Refaat, Tamer F.; Yu, Jirong; Antill, Charles W.; Taylor, Bryant D.; Bowen, Stephen C.; Welters, Angela M.; Remus, Ruben G.; Wong, Teh-Hwa; Reithmaier, Karl; Lee, Jane; Ismail, Syed

2017-09-01

An airborne 2-μm triple-pulse integrated path differential absorption (IPDA) lidar is currently under development at NASA Langley Research Center (LaRC). This lidar targets both atmospheric carbon dioxide (CO2) and water vapor (H2O) column measurements, simultaneously. Advancements in the development of this IPDA lidar are presented in this paper. Updates on advanced two-micron triple-pulse high-energy laser transmitter will be given including packaging and lidar integration status. In addition, receiver development updates will also be presented. This includes a state-of-the-art detection system integrated at NASA Goddard Space Flight Center. This detection system is based on a newly developed HgCdTe (MCT) electron-initiated avalanche photodiode (e-APD) array. Future plan for IPDA lidar system for ground integration, testing and flight validation will be discussed.

OCEANET-Atmosphere - The Autonomous Measurement Container

NASA Astrophysics Data System (ADS)

Kalisch, John; Macke, Andreas; Althausen, Dietrich; Bumke, Karl; Engelmann, Ronny; Kanitz, Thomas; Kleta, Henry; Zoll, Yann

2010-05-01

OCEANET-Atmosphere is a joint venture project of IFM-GEOMAR and IFT to study the mass and energy transfer of ocean and atmosphere by introducing a special measurement container, which is suitable to perform a large spectrum of atmospheric underway measurements on offshore research vessels and cargo ships. The container combines state-of-the-art measurement devices and connect them to its own computer network to realize a comprehensive system for remote sensing. A Raman-lidar measures marine and anthropogenic optical aerosol properities by analyzing the elastic signal and the vibration-rotation Raman signal of nitrogen. Our passive microwave radiometer determines the integrated water vapor and the liquid water path of the atmospheric column, as well as vertical temperature and humidity profiles. Carbon dioxide is measured high-frequent. Turbulence measurements are performed by means of a sonic anemometer. In combination with fast humidity sensors the fluxes of momentum, latent and sensible heat are derived. An automatic full sky imager monitors the state of the cloudy sky. A selection of standard meteorological devices measure air temperature, humidity, wind velocity, wind speed and downward shortwave and longwave radiative fluxes. The GPS sensors register navigational data. For an almost real time monitoring of a data subset our telemetry system is sending short hourly data reports via satellite. OCEANET-Atmosphere is set up to improve the quantity and the quality of atmospheric data sets on intercontinental oceanic transects, where the previous data base is still weak. A first research mission has been performed onboard RV Polarstern at ANT XXVI/1.

Global Atmosphere Watch Workshop on Measurement-Model ...

EPA Pesticide Factsheets

The World Meteorological Organization’s (WMO) Global Atmosphere Watch (GAW) Programme coordinates high-quality observations of atmospheric composition from global to local scales with the aim to drive high-quality and high-impact science while co-producing a new generation of products and services. In line with this vision, GAW’s Scientific Advisory Group for Total Atmospheric Deposition (SAG-TAD) has a mandate to produce global maps of wet, dry and total atmospheric deposition for important atmospheric chemicals to enable research into biogeochemical cycles and assessments of ecosystem and human health effects. The most suitable scientific approach for this activity is the emerging technique of measurement-model fusion for total atmospheric deposition. This technique requires global-scale measurements of atmospheric trace gases, particles, precipitation composition and precipitation depth, as well as predictions of the same from global/regional chemical transport models. The fusion of measurement and model results requires data assimilation and mapping techniques. The objective of the GAW Workshop on Measurement-Model Fusion for Global Total Atmospheric Deposition (MMF-GTAD), an initiative of the SAG-TAD, was to review the state-of-the-science and explore the feasibility and methodology of producing, on a routine retrospective basis, global maps of atmospheric gas and aerosol concentrations as well as wet, dry and total deposition via measurement-model

Influence of aerosol chemical composition on N2O5 uptake: airborne regional measurements in North-Western Europe

NASA Astrophysics Data System (ADS)

Morgan, W. T.; Ouyang, B.; Allan, J. D.; Aruffo, E.; Di Carlo, P.; Kennedy, O. J.; Lowe, D.; Flynn, M. J.; Rosenberg, P. D.; Williams, P. I.; Jones, R.; McFiggans, G. B.; Coe, H.

2014-07-01

Aerosol chemical composition was found to influence nighttime atmospheric chemistry during a series of airborne measurements in North-Western Europe in summer conditions, which has implications for regional air quality and climate. The uptake of dinitrogen pentoxide, γ (N2O5), to particle surfaces was found to be modulated by the amount of water content and ammonium nitrate present in the aerosol. The conditions prevalent in this study suggest that the net uptake rate of N2O5 to atmospheric aerosols was relatively efficient compared to previous studies, with γ (N2O5) values in the range 0.01-0.03. This is likely a consequence of the elevated relative humidity in the region, which promotes greater aerosol water content. Increased nitrate concentrations relative to particulate water were found to suppress N2O5 uptake. The results presented here contrast with previous ambient studies of N2O5 uptake, which have generally taken place in low-nitrate environments in the USA. Comparison of the N2O5 uptake derived from the measurements with a parameterised scheme that is based on the ratio of particulate water to nitrate yielded reasonably good agreement in terms of the magnitude and variation in uptake, provided the effect of chloride was neglected. An additional suppression of the parameterised uptake is likely required to fully capture the variation in N2O5 uptake, which could be achieved via the known suppression by organic aerosol. However, existing parameterisations representing the suppression by organic aerosol were unable to fully represent the variation in N2O5 uptake. These results provide important ambient measurement constraint on our ability to predict N2O5 uptake in regional and global aerosol models. N2O5 uptake is a potentially important source of nitrate aerosol and a sink of the nitrate radical, which is the main nocturnal oxidant in the atmosphere. The results further highlight the importance of ammonium nitrate in North-Western Europe as a key

The Atmospheric Distribution of Molecular Hydrogen (H2) and Related Species During HIPPO and Other Recent Airborne Missions

NASA Astrophysics Data System (ADS)

Hintsa, E. J.; Moore, F. L.; Dutton, G. S.; Hall, B. D.; Nance, J. D.; Hurst, D. F.; Novelli, P. C.; Elkins, J. W.; Daube, B.; Kort, E. A.; Pittman, J. V.; Santoni, G. W.; Wofsy, S. C.; Jaegle, L.

2012-12-01

The goal of the HIAPER Pole-to-Pole Observations (HIPPO) of Carbon Cycle and Greenhouse Gases Study was to measure a large set of trace gases and aerosols as a function of altitude and latitude in different seasons in order to better understand their sources, sinks, and atmospheric transport, and to use these measurements to compare with a variety of chemical transport models, ultimately leading to improvements in the models. The NSF/NCAR Gulfstream V (GV) aircraft (formerly known as HIAPER) was equipped with instruments for trace gases, aerosols, and meteorological parameters, and flew a set of five transects in 2009-2011 from Colorado, to Anchorage, AK, to near the North Pole, then south to Christchurch, NZ, toward the edge of Antarctica, and back to the northern hemisphere high latitudes, with intermediate stops at different locations in the Pacific Ocean. On each leg of the journey, the GV carried out a series of profiles from the marine (or continental) boundary layer to the stratosphere, generating a set of altitude/latitude slices of the atmosphere in different seasons (January 2009, October-November 2009, March-April 2010, June-July 2011, and August-September 2011). While HIPPO was in progress, data were also obtained at higher altitudes in the stratosphere over the Pacific Ocean from the NASA Global Hawk aircraft during the GloPac (Global Hawk Pacific; March-April 2010) and ATTREX (Airborne Tropical Tropopause Experiment; October-November 2011) missions, respectively. In this presentation, results are shown that were obtained from the UCATS and PANTHER instruments and other sensors on board the GV and the Global Hawk. UCATS (the UAS Chromatograph for Atmospheric Trace Species) flew on both platforms and was configured to measure N2O, SF6, H2, CH4, CO, water vapor, and ozone. PANTHER (PAN and other Trace Hydrohalocarbon ExpeRiment) measures an even larger set of trace gases with gas chromatography and a mass spectrometer, and flew on every leg of HIPPO. The

New techniques for laser beam atmospheric extinction measurements from manned and unmanned aerospace vehicles

NASA Astrophysics Data System (ADS)

Sabatini, Roberto; Richardson, Mark

2013-03-01

Novel techniques for laser beam atmospheric extinction measurements, suitable for several air and space platform applications, are presented in this paper. Extinction measurements are essential to support the engineering development and the operational employment of a variety of aerospace electro-optical sensor systems, allowing calculation of the range performance attainable with such systems in current and likely future applications. Such applications include ranging, weaponry, Earth remote sensing and possible planetary exploration missions performed by satellites and unmanned flight vehicles. Unlike traditional LIDAR methods, the proposed techniques are based on measurements of the laser energy (intensity and spatial distribution) incident on target surfaces of known geometric and reflective characteristics, by means of infrared detectors and/or infrared cameras calibrated for radiance. Various laser sources can be employed with wavelengths from the visible to the far infrared portions of the spectrum, allowing for data correlation and extended sensitivity. Errors affecting measurements performed using the proposed methods are discussed in the paper and algorithms are proposed that allow a direct determination of the atmospheric transmittance and spatial characteristics of the laser spot. These algorithms take into account a variety of linear and non-linear propagation effects. Finally, results are presented relative to some experimental activities performed to validate the proposed techniques. Particularly, data are presented relative to both ground and flight trials performed with laser systems operating in the near infrared (NIR) at λ= 1064 nm and λ= 1550 nm. This includes ground tests performed with 10 Hz and 20 KHz PRF NIR laser systems in a large variety of atmospheric conditions, and flight trials performed with a 10 Hz airborne NIR laser system installed on a TORNADO aircraft, flying up to altitudes of 22,000 ft.

Spatio-temporal variability of airborne bacterial communities and their correlation with particulate matter chemical composition across two urban areas.

PubMed

Gandolfi, I; Bertolini, V; Bestetti, G; Ambrosini, R; Innocente, E; Rampazzo, G; Papacchini, M; Franzetti, A

2015-06-01

The study of spatio-temporal variability of airborne bacterial communities has recently gained importance due to the evidence that airborne bacteria are involved in atmospheric processes and can affect human health. In this work, we described the structure of airborne microbial communities in two urban areas (Milan and Venice, Northern Italy) through the sequencing, by the Illumina platform, of libraries containing the V5-V6 hypervariable regions of the 16S rRNA gene and estimated the abundance of airborne bacteria with quantitative PCR (qPCR). Airborne microbial communities were dominated by few taxa, particularly Burkholderiales and Actinomycetales, more abundant in colder seasons, and Chloroplasts, more abundant in warmer seasons. By partitioning the variation in bacterial community structure, we could assess that environmental and meteorological conditions, including variability between cities and seasons, were the major determinants of the observed variation in bacterial community structure, while chemical composition of atmospheric particulate matter (PM) had a minor contribution. Particularly, Ba, SO4 (2-) and Mg(2+) concentrations were significantly correlated with microbial community structure, but it was not possible to assess whether they simply co-varied with seasonal shifts of bacterial inputs to the atmosphere, or their variation favoured specific taxa. Both local sources of bacteria and atmospheric dispersal were involved in the assembling of airborne microbial communities, as suggested, to the one side by the large abundance of bacteria typical of lagoon environments (Rhodobacterales) observed in spring air samples from Venice and to the other by the significant effect of wind speed in shaping airborne bacterial communities at all sites.

Upper atmosphere pollution measurements (GASP)

NASA Technical Reports Server (NTRS)

Rudey, R. A.; Holdeman, J. D.

1975-01-01

The environmental effects are discussed of engine effluents of future large fleets of aircraft operating in the stratosphere. Topics discussed include: atmospheric properties, aircraft engine effluents, upper atmospheric measurements, global air sampling, and data reduction and analysis

Remote Sensing of Wind Fields and Aerosol Distribution with Airborne Scanning Doppler Lidar

NASA Technical Reports Server (NTRS)

Rothermel, Jeffry; Cutten, Dean R.; Johnson, Steven C.; Jazembski, Maurice; Arnold, James E. (Technical Monitor)

2001-01-01

The coherent Doppler laser radar (lidar), when operated from an airborne platform, is a unique tool for the study of atmospheric and surface processes and features. This is especially true for scientific objectives requiring measurements in optically-clear air, where other remote sensing technologies such as Doppler radar are typically at a disadvantage. The atmospheric lidar remote sensing groups of several US institutions, led by Marshall Space Flight Center, have developed an airborne coherent Doppler lidar capable of mapping the wind field and aerosol structure in three dimensions. The instrument consists of an eye-safe approx. 1 Joule/pulse lidar transceiver, telescope, scanner, inertial measurement unit, and flight computer system to orchestrate all subsystem functions and tasks. The scanner is capable of directing the expanded lidar beam in a variety of ways, in order to extract vertically-resolved wind fields. Horizontal resolution is approx. 1 km; vertical resolution is even finer. Winds are obtained by measuring backscattered, Doppler-shifted laser radiation from naturally-occurring aerosol particles (of order 1 micron diameter). Measurement coverage depends on aerosol spatial distribution and composition. Velocity accuracy has been verified to be approx. 1 meter per second. A variety of applications have been demonstrated during the three flight campaigns conducted during 1995-1998. Examples will be shown during the presentation. In 1995, boundary layer winds over the ocean were mapped with unprecedented resolution. In 1996, unique measurements were made of. flow over the complex terrain of the Aleutian Islands; interaction of the marine boundary layer jet with the California coastal mountain range; a weak dry line in Texas - New Mexico; the angular dependence of sea surface scattering; and in-flight radiometric calibration using the surface of White Sands National Monument. In 1998, the first measurements of eyewall and boundary layer winds within a

On the impact of a refined stochastic model for airborne LiDAR measurements

NASA Astrophysics Data System (ADS)

Bolkas, Dimitrios; Fotopoulos, Georgia; Glennie, Craig

2016-09-01

Accurate topographic information is critical for a number of applications in science and engineering. In recent years, airborne light detection and ranging (LiDAR) has become a standard tool for acquiring high quality topographic information. The assessment of airborne LiDAR derived DEMs is typically based on (i) independent ground control points and (ii) forward error propagation utilizing the LiDAR geo-referencing equation. The latter approach is dependent on the stochastic model information of the LiDAR observation components. In this paper, the well-known statistical tool of variance component estimation (VCE) is implemented for a dataset in Houston, Texas, in order to refine the initial stochastic information. Simulations demonstrate the impact of stochastic-model refinement for two practical applications, namely coastal inundation mapping and surface displacement estimation. Results highlight scenarios where erroneous stochastic information is detrimental. Furthermore, the refined stochastic information provides insights on the effect of each LiDAR measurement in the airborne LiDAR error budget. The latter is important for targeting future advancements in order to improve point cloud accuracy.

Rapid, optical measurement of the atmospheric pressure on a fast research aircraft using open-path TDLAS

NASA Astrophysics Data System (ADS)

Buchholz, B.; Afchine, A.; Ebert, V.

2014-05-01

Because of the high travel speed, the complex flow dynamics around an aircraft and the complex dependency of the fluid dynamics on numerous airborne parameters, it is quite difficult to obtain accurate pressure values at a specific instrument location of an aircraft's fuselage. Complex simulations using computational fluid dynamics (CFD) models can in theory computationally "transfer" pressure values from one location to another. However, for long flight patterns, this process is inconvenient and cumbersome. Furthermore these CFD transfer models require a local experimental validation, which is rarely available. In this paper, we describe an integrated approach for a spectroscopic, calibration-free, in-flight pressure determination in an open-path White cell on an aircraft fuselage using ambient, atmospheric water vapour as the "sensor species". The presented measurements are realized with the HAI (Hygrometer for Atmospheric Investigations) instrument, built for multiphase water detection via calibration-free TDLAS (tunable diode laser absorption spectroscopy). The pressure determination is based on raw data used for H2O concentration measurement, but with a different post-flight evaluation method, and can therefore be conducted at deferred time intervals on any desired flight track. The spectroscopic pressure is compared in-flight with the static ambient pressure of the aircraft avionic system and a micro-mechanical pressure sensor, located next to the open-path cell, over a pressure range from 150 hPa to 800 hPa, and a water vapour concentration range of more than three orders of magnitude. The correlation between the micro-mechanical pressure sensor measurements and the spectroscopic pressure measurements show an average deviation from linearity of only 0.14% and a small offset of 9.5 hPa. For the spectroscopic pressure evaluation we derive measurement uncertainties under laboratory conditions of 3.2% and 5.1% during in flight operation on the HALO airplane

Rapid, optical measurement of the atmospheric pressure on a fast research aircraft using open-path TDLAS

NASA Astrophysics Data System (ADS)

Buchholz, B.; Afchine, A.; Ebert, V.

2014-11-01

Because of the high travel speed, the complex flow dynamics around an aircraft, and the complex dependency of the fluid dynamics on numerous airborne parameters, it is quite difficult to obtain accurate pressure values at a specific instrument location of an aircraft's fuselage. Complex simulations using computational fluid dynamics (CFD) models can in theory computationally "transfer" pressure values from one location to another. However, for long flight patterns, this process is inconvenient and cumbersome. Furthermore, these CFD transfer models require a local experimental validation, which is rarely available. In this paper, we describe an integrated approach for a spectroscopic, calibration-free, in-flight pressure determination in an open-path White cell on an aircraft fuselage using ambient, atmospheric water vapour as the "sensor species". The presented measurements are realised with the HAI (Hygrometer for Atmospheric Investigations) instrument, built for multiphase water detection via calibration-free TDLAS (tunable diode laser absorption spectroscopy). The pressure determination is based on raw data used for H2O concentration measurement, but with a different post-flight evaluation method, and can therefore be conducted at deferred time intervals on any desired flight track. The spectroscopic pressure is compared in-flight with the static ambient pressure of the aircraft avionic system and a micro-mechanical pressure sensor, located next to the open-path cell, over a pressure range from 150 to 800 hPa, and a water vapour concentration range of more than 3 orders of magnitude. The correlation between the micro-mechanical pressure sensor measurements and the spectroscopic pressure measurements shows an average deviation from linearity of only 0.14% and a small offset of 9.5 hPa. For the spectroscopic pressure evaluation we derive measurement uncertainties under laboratory conditions of 3.2 and 5.1% during in-flight operation on the HALO airplane. Under

Constraints on oceanic methane emissions west of Svalbard from atmospheric in situ measurements and Lagrangian transport modeling.

PubMed

Pisso, I; Myhre, C Lund; Platt, S M; Eckhardt, S; Hermansen, O; Schmidbauer, N; Mienert, J; Vadakkepuliyambatta, S; Bauguitte, S; Pitt, J; Allen, G; Bower, K N; O'Shea, S; Gallagher, M W; Percival, C J; Pyle, J; Cain, M; Stohl, A

2016-12-16

Methane stored in seabed reservoirs such as methane hydrates can reach the atmosphere in the form of bubbles or dissolved in water. Hydrates could destabilize with rising temperature further increasing greenhouse gas emissions in a warming climate. To assess the impact of oceanic emissions from the area west of Svalbard, where methane hydrates are abundant, we used measurements collected with a research aircraft (Facility for Airborne Atmospheric Measurements) and a ship (Helmer Hansen) during the Summer 2014 and for Zeppelin Observatory for the full year. We present a model-supported analysis of the atmospheric CH 4 mixing ratios measured by the different platforms. To address uncertainty about where CH 4 emissions actually occur, we explored three scenarios: areas with known seeps, a hydrate stability model, and an ocean depth criterion. We then used a budget analysis and a Lagrangian particle dispersion model to compare measurements taken upwind and downwind of the potential CH 4 emission areas. We found small differences between the CH 4 mixing ratios measured upwind and downwind of the potential emission areas during the campaign. By taking into account measurement and sampling uncertainties and by determining the sensitivity of the measured mixing ratios to potential oceanic emissions, we provide upper limits for the CH 4 fluxes. The CH 4 flux during the campaign was small, with an upper limit of 2.5 nmol m -2  s -1 in the stability model scenario. The Zeppelin Observatory data for 2014 suggest CH 4 fluxes from the Svalbard continental platform below 0.2 Tg yr -1 . All estimates are in the lower range of values previously reported.

Constraints on oceanic methane emissions west of Svalbard from atmospheric in situ measurements and Lagrangian transport modeling

PubMed Central

Myhre, C. Lund; Platt, S. M.; Eckhardt, S.; Hermansen, O.; Schmidbauer, N.; Mienert, J.; Vadakkepuliyambatta, S.; Bauguitte, S.; Pitt, J.; Allen, G.; Bower, K. N.; O'Shea, S.; Gallagher, M. W.; Percival, C. J.; Pyle, J.; Cain, M.; Stohl, A.

2016-01-01

Abstract Methane stored in seabed reservoirs such as methane hydrates can reach the atmosphere in the form of bubbles or dissolved in water. Hydrates could destabilize with rising temperature further increasing greenhouse gas emissions in a warming climate. To assess the impact of oceanic emissions from the area west of Svalbard, where methane hydrates are abundant, we used measurements collected with a research aircraft (Facility for Airborne Atmospheric Measurements) and a ship (Helmer Hansen) during the Summer 2014 and for Zeppelin Observatory for the full year. We present a model‐supported analysis of the atmospheric CH4 mixing ratios measured by the different platforms. To address uncertainty about where CH4 emissions actually occur, we explored three scenarios: areas with known seeps, a hydrate stability model, and an ocean depth criterion. We then used a budget analysis and a Lagrangian particle dispersion model to compare measurements taken upwind and downwind of the potential CH4 emission areas. We found small differences between the CH4 mixing ratios measured upwind and downwind of the potential emission areas during the campaign. By taking into account measurement and sampling uncertainties and by determining the sensitivity of the measured mixing ratios to potential oceanic emissions, we provide upper limits for the CH4 fluxes. The CH4 flux during the campaign was small, with an upper limit of 2.5 nmol m−2 s−1 in the stability model scenario. The Zeppelin Observatory data for 2014 suggest CH4 fluxes from the Svalbard continental platform below 0.2 Tg yr−1. All estimates are in the lower range of values previously reported. PMID:28261536

Constraints on oceanic methane emissions west of Svalbard from atmospheric in situ measurements and Lagrangian transport modeling

NASA Astrophysics Data System (ADS)

Pisso, I.; Myhre, C. Lund; Platt, S. M.; Eckhardt, S.; Hermansen, O.; Schmidbauer, N.; Mienert, J.; Vadakkepuliyambatta, S.; Bauguitte, S.; Pitt, J.; Allen, G.; Bower, K. N.; O'Shea, S.; Gallagher, M. W.; Percival, C. J.; Pyle, J.; Cain, M.; Stohl, A.

2016-12-01

Methane stored in seabed reservoirs such as methane hydrates can reach the atmosphere in the form of bubbles or dissolved in water. Hydrates could destabilize with rising temperature further increasing greenhouse gas emissions in a warming climate. To assess the impact of oceanic emissions from the area west of Svalbard, where methane hydrates are abundant, we used measurements collected with a research aircraft (Facility for Airborne Atmospheric Measurements) and a ship (Helmer Hansen) during the Summer 2014 and for Zeppelin Observatory for the full year. We present a model-supported analysis of the atmospheric CH4 mixing ratios measured by the different platforms. To address uncertainty about where CH4 emissions actually occur, we explored three scenarios: areas with known seeps, a hydrate stability model, and an ocean depth criterion. We then used a budget analysis and a Lagrangian particle dispersion model to compare measurements taken upwind and downwind of the potential CH4 emission areas. We found small differences between the CH4 mixing ratios measured upwind and downwind of the potential emission areas during the campaign. By taking into account measurement and sampling uncertainties and by determining the sensitivity of the measured mixing ratios to potential oceanic emissions, we provide upper limits for the CH4 fluxes. The CH4 flux during the campaign was small, with an upper limit of 2.5 nmol m-2 s-1 in the stability model scenario. The Zeppelin Observatory data for 2014 suggest CH4 fluxes from the Svalbard continental platform below 0.2 Tg yr-1. All estimates are in the lower range of values previously reported.

Airborne Observations of Urban-Derived Water Vapor and Potential Impacts on Chemistry and Clouds

NASA Astrophysics Data System (ADS)

Salmon, O. E.; Shepson, P. B.; Grundman, R. M., II; Stirm, B. H.; Ren, X.; Dickerson, R. R.; Fuentes, J. D.

2015-12-01

Atmospheric conditions typical of wintertime, such as lower boundary layer heights and reduced turbulent mixing, provide a unique environment for anthropogenic pollutants to accumulate and react. Wintertime enhancements in water vapor (H2O) have been observed in urban areas, and are thought to result from fossil fuel combustion and urban heat island-induced evaporation. The contribution of urban-derived water vapor to the atmosphere has the potential to locally influence atmospheric chemistry and weather for the urban area and surrounding region due to interactions between H2O and other chemical species, aerosols, and clouds. Airborne observations of urban-derived H2O, carbon dioxide (CO2), methane, nitrogen dioxide (NO2), ozone, and aerosols were conducted from Purdue University's Airborne Laboratory for Atmospheric Research (ALAR) and the University of Maryland's (UMD) Twin Cessna research aircraft during the winter of 2015. Measurements were conducted as part of the collaborative airborne campaign, Wintertime INvestigation of Transport, Emissions, and Reactivity (WINTER), which investigated seasonal trends in anthropogenic emissions and reactivity in the Northeastern United States. ALAR and the UMD aircraft participated in mass balance experiments around Washington D.C.-Baltimore to determine total city emission rates of H2O and other greenhouse gases. Average enhancements in H2O mixing ratio of 0.048%, and up to 0.13%, were observed downwind of the urban centers on ten research flights. In some cases, downwind H2O concentrations clearly track CO2 and NO2 enhancements, suggesting a strong combustion signal. Analysis of Purdue and UMD data collected during the WINTER campaign shows an average urban-derived H2O contribution of 5.3%, and as much as 13%, to the local boundary layer from ten research flights flown in February and March of 2015. In this paper, we discuss the potential chemical and physical implications of these results.

Remote measurement of atmospheric pollutants

NASA Technical Reports Server (NTRS)

Allario, F.; Hoell, J.; Seals, R. K.

1979-01-01

The concentration and vertical distribution of atmospheric ammonia and ozone are remotely sensed, using dual-C02-laser multichannel infrared Heterodyne Spectrometer (1HS). Innovation makes atmospheric pollution measurements possible with nearly-quantum-noise-limited sensitivity and ultrafine spectral resolution.

Innovative measurement within the atmosphere of Venus.

NASA Astrophysics Data System (ADS)

Ekonomov, Alexey; Linkin, Vyacheslav; Manukin, Anatoly; Makarov, Vladislav; Lipatov, Alexander

The results of Vega project experiments with two balloons flew in the cloud layer of the atmosphere of Venus are analyzed as to the superrotation nature and local dynamic and thermodynamic characteristics of the atmosphere. These balloons in conjunction with measurements of temperature profiles defined by the Fourier spectrometer measurements from the spacecraft Venera 15 allow us to offer a mechanism accelerating the atmosphere to high zonal velocities and supporting these speeds, the atmosphere superrotation in general. Spectral measurements with balloons confirm the possibility of imaging the planet's surface from a height of not more than 55 km. Promising experiments with balloons in the atmosphere of Venus are considered. In particular, we discuss the possibility of measuring the geopotential height, as Venus no seas and oceans to vertical positioning of the temperature profiles. As an innovative research facilities within the atmosphere overpressure balloon with a lifetime longer than 14 Earth days and vertical profile microprobes are considered.

Radon measurements aboard the Kuiper Airborne Observatory

NASA Technical Reports Server (NTRS)

Kritz, Mark A.; Rosner, Stefan W.

1995-01-01

We have carried out three (piggyback) radon-related projects aboard the KAO. The first, which was limited to upper tropospheric measurements while in level flight, revealed the systematic occurrence of unexpectedly high radon concentrations in this region of the atmosphere. The second project was an instrument development project, which led to the installation of an automatic radon measurement system aboard the NASA ER-2 High Altitude Research Aircraft. In the third, we installed a new system capable of collecting samples during the normal climb and descent of the KAO. The results obtained in these projects have resulted in significant contributions to our knowledge of atmospheric transport processes, and are currently playing a key role in the validation of global circulation and transport models.

Results of airborne measurements in the plume near and far from the 2014 Bardarbunga-Holuhraun eruption.

NASA Astrophysics Data System (ADS)

Arnason, Gylfi; Eliasson, Jonas; Weber, Konradin; Boehlke, Christoph; Palsson, Thorgeir; Rognvaldsson, Olafur; Thorsteinsson, Throstur; Platt, Ulrich; Tirpitz, Lukas; Jones, Roderic L.; Smith, Paul D.

2015-04-01

The Volcanic Ash Research (VAR) group is focused on airborne measurement of ash contamination to support safe air travel. In relations to the recent eruption, the group measured ash and several gaseous species in the plume 10-300 km from the volcano. The eruption emitted ash turned out to be mostly in the fine aerosol range (much less than 10 micrometers in diameter). Our highest measured concentrations were lower than 1 mg/m3 indicating that commercial air traffic was not threatened (greater than 2 mg/m3) by the ash contamination. But we measured sulfur dioxide (SO2 ) up to 90 mg/m3, which presented a potentially dangerous pollution problem. However, airborne measurements indicate that the sulfur concentration decays (probably due to scavenging) as the plume is carried by the wind from the volcano, which limits the area of immediate danger to the public. Here we present size distribution for particulate matter collected during flights, near and far from the crater at various times. The particle data is then compared with simultaneously collected sulfur dioxide data and the rate of decay of is estimated. Sulfur and particle concentration variations with height in the far plume are presented. Some airborne measurements for H2S, NO, NO2 and CO2 will also be presented. This includes correlation matrices for simultaneous measurements of these gases and comparison to National Air Quality Standards and background values.

Gross-alpha and gross-beta activities in airborne particulate samples. Analysis and prediction models.

PubMed

Dueñas, C; Fernández, M C; Carretero, J; Liger, E; Cañete, S

2001-04-01

Measurements of gross-alpha and gross-beta activities were made every week during the years 1992-1997 for airborne particulate samples collected using air filters at a clear site. The data are sufficiently numerous to allow the examination of variations in time and by these measurements to establish several features that should be important in understanding any trends of atmospheric radioactivity. Two models were used to predict the gross-alpha and gross-beta activities. A good agreement between the results of these models and the measurements was highlighted.

Hyperspectral Observations of Land Surfaces Using Ground-based, Airborne, and Satellite Sensors

NASA Astrophysics Data System (ADS)

Knuteson, R. O.; Best, F. A.; Revercomb, H. E.; Tobin, D. C.

2006-12-01

The University of Wisconsin-Madison Space Science and Engineering Center (UW-SSEC) has helped pioneer the use of high spectral resolution infrared spectrometers for application to atmospheric and surface remote sensing. This paper is focused on observations of land surface infrared emission from high spectral resolution measurements collected over the past 15 years using airborne, ground-based, and satellite platforms. The earliest data was collected by the High-resolution Interferometer Sounder (HIS), an instrument designed in the 1980s for operation on the NASA ER-2 high altitude aircraft. The HIS was replaced in the late 1990s by the Scanning-HIS instrument which has flown on the NASA ER-2, WB-57, DC-8, and Scaled Composites Proteus aircraft and continues to support field campaigns, such as those for EOS Terra, Aqua, and Aura validation. Since 1995 the UW-SSEC has fielded a ground-based Atmospheric Emitted Radiance Interferometer (AERI) in a research vehicle (the AERIBAGO) which has allowed for direct field measurements of land surface emission from a height of about 16 ft above the ground. Several ground-based and aircraft campaigns were conducted to survey the region surrounding the ARM Southern Great Plains site in north central Oklahoma. The ground- based AERIBAGO has also participated in surface emissivity campaigns in the Western U.S.. Since 2002, the NASA Atmospheric InfraRed Sounder (AIRS) has provided similar measurements from the Aqua platform in an afternoon sun-synchronous polar orbit. Ground-based and airborne observations are being used to validate the land surface products derived from the AIRS observations. These cal/val activities are in preparation for similar measurements anticipated from the operational Cross-track InfraRed Sounder (CrIS) on the NPOESS Preparatory Platform (NPP), expected to be launched in 2008. Moreover, high spectral infrared observations will soon be made by the Infrared Atmospheric Sounder Interferometer (IASI) on the

Airborne laser ranging system for monitoring regional crustal deformation

NASA Technical Reports Server (NTRS)

Degnan, J. J.

1981-01-01

Alternate approaches for making the atmospheric correction without benefit of a ground-based meteorological network are discussed. These include (1) a two-color channel that determines the atmospheric correction by measuring the time delay induced by dispersion between pulses at two optical frequencies; (2) single-color range measurements supported by an onboard temperature sounder, pressure altimeter readings, and surface measurements by a few existing meteorological facilities; and (3) inclusion of the quadratic polynomial coefficients as variables to be solved for along with target coordinates in the reduction of the single-color range data. It is anticipated that the initial Airborne Laser Ranging System (ALRS) experiments will be carried out in Southern California in a region bounded by Santa Barbara on the norht and the Mexican border on the south. The target area will be bounded by the Pacific Ocean to the west and will extend eastward for approximately 400 km. The unique ability of the ALRS to provide a geodetic 'snapshot' of such a large area will make it a valuable geophysical tool.

An Assessment of the Need for Standard Variable Names for Airborne Field Campaigns

NASA Astrophysics Data System (ADS)

Beach, A. L., III; Chen, G.; Northup, E. A.; Kusterer, J.; Quam, B. M.

2017-12-01

The NASA Earth Venture Program has led to a dramatic increase in airborne observations, requiring updated data management practices with clearly defined data standards and protocols for metadata. An airborne field campaign can involve multiple aircraft and a variety of instruments. It is quite common to have different instruments/techniques measure the same parameter on one or more aircraft platforms. This creates a need to allow instrument Principal Investigators (PIs) to name their variables in a way that would distinguish them across various data sets. A lack of standardization of variables names presents a challenge for data search tools in enabling discovery of similar data across airborne studies, aircraft platforms, and instruments. This was also identified by data users as one of the top issues in data use. One effective approach for mitigating this problem is to enforce variable name standardization, which can effectively map the unique PI variable names to fixed standard names. In order to ensure consistency amongst the standard names, it will be necessary to choose them from a controlled list. However, no such list currently exists despite a number of previous efforts to establish a sufficient list of atmospheric variable names. The Atmospheric Composition Variable Standard Name Working Group was established under the auspices of NASA's Earth Science Data Systems Working Group (ESDSWG) to solicit research community feedback to create a list of standard names that are acceptable to data providers and data users This presentation will discuss the challenges and recommendations of standard variable names in an effort to demonstrate how airborne metadata curation/management can be improved to streamline data ingest, improve interoperability, and discoverability to a broader user community.

Anthropogenic plumes from metropolitan areas and biomass burning emissions in West Africa during DACCIWA - airborne measurements on board the DLR Falcon 20

NASA Astrophysics Data System (ADS)

Stratmann, Greta; Schlager, Hans; Sauer, Daniel; Brocchi, Vanessa; Catoire, Valery; Baumann, Robert

2017-04-01

The DACCIWA (Dynamics-Aerosol-Chemistry-Cloud Interactions over West Africa) airborne field campaign was conducted in Southern West Africa in June/July 2016. Three European research aircraft (DLR - Falcon 20, SAFIRE - ATR 42 and BAS - Twin Otter) were deployed from Lomé/Togo and conducted research flights across Ivory Coast, Ghana, Togo and Benin. On board the DLR Falcon O3, SO2, CO, NO2 and aerosol fine mode particle number concentration and size distribution were measured during a total of 12 scientific flights. Until now only few airborne trace gas measurements were conducted in Southern West Africa. Therefore, this field experiment contributes to the knowledge of the chemical composition of the lower troposphere between 0 - 4 km. During several flights pollution plumes from major population centers - Lomé/Togo, Accra/Ghana, Kumasi/Ghana, and Abidjan/Ivory Coast - were probed below, inside and above clouds. Here, enhanced trace gas and particle concentrations were observed. In addition, plumes from biomass burning emissions were detected which were transported to West Africa. The composition of the pollution plumes are presented as well as transport pathways using HYSPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectories) trajectory calculations. Ozone enhancements in the biomass burning pollution plumes of up to 70 ppb were observed compared to background concentrations of 30-40 ppb. Furthermore, HYSPLIT atmospheric dispersion simulations are used to estimate anthropogenic SO2 city emissions.

Measurement of airborne ultrasonic slow waves in calcaneal cancellous bone.

PubMed

Strelitzki, R; Paech, V; Nicholson, P H

1999-05-01

Measurements of an airborne ultrasonic wave were made in defatted cancellous bone from the human calcaneus using standard ultrasonic equipment. The wave propagating under these conditions was consistent with a decoupled Biot slow wave travelling in the air alone, as previously reported in gas-saturated foams. Reproducible measurements of phase velocity and attenuation coefficient were possible, and an estimate of the tortuosity of the trabecular framework was derived from the high frequency limit of the phase velocity. Thus the method offers a new approach to the acoustic characterisation of bone in vitro which, in contrast to existing techniques, has the potential to yield information directly characterising the trabecular structure.

The effects of temperature and pressure on airborne exposure concentrations when performing compliance evaluations using ACGIH TLVs and OSHA PELs.

PubMed

Stephenson, D J; Lillquist, D R

2001-04-01

Occupational hygienists perform air sampling to characterize airborne contaminant emissions, assess occupational exposures, and establish allowable workplace airborne exposure concentrations. To perform these air sampling applications, occupational hygienists often compare an airborne exposure concentration to a corresponding American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV) or an Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL). To perform such comparisons, one must understand the physiological assumptions used to establish these occupational exposure limits, the relationship between a workplace airborne exposure concentration and its associated TLV or PEL, and the effect of temperature and pressure on the performance of an accurate compliance evaluation. This article illustrates the correct procedure for performing compliance evaluations using airborne exposure concentrations expressed in both parts per million and milligrams per cubic meter. In so doing, a brief discussion is given on the physiological assumptions used to establish TLVs and PELs. It is further shown how an accurate compliance evaluation is fundamentally based on comparison of a measured work site exposure dose (derived from the sampling site exposure concentration estimate) to an estimated acceptable exposure dose (derived from the occupational exposure limit concentration). In addition, this article correctly illustrates the effect that atmospheric temperature and pressure have on airborne exposure concentrations and the eventual performance of a compliance evaluation. This article also reveals that under fairly moderate conditions of temperature and pressure, 30 degrees C and 670 torr, a misunderstanding of how varying atmospheric conditions affect concentration values can lead to a 15 percent error in assessing compliance.

Airborne measurement of submicron aerosol number concentration and CCN activity in and around the Korean Peninsula and their comparison to ground measurement in Seoul

NASA Astrophysics Data System (ADS)

Park, M.; Kim, N.; Yum, S. S.

2016-12-01

Aerosols exert impact not only on human health and visibility but also on climate change directly by scattering or absorbing solar radiation and indirectly by acting as cloud condensation nuclei (CCN) and thus altering cloud radiative and microphysical properties. Aerosol indirect effects on climate has been known to have large uncertainty because of insufficient measurement data on aerosol and CCN activity distribution. Submicron aerosol number concentration (NCN, TSI CPC) and CCN number concentration (NCCN, DMT CCNC) were measured on board the NASA DC-8 research aircraft and at a ground site at Olympic Park in Seoul from May 2nd to June 10th, 2016. CCNC on the airborne platform was operated with the fixed internal supersaturation of 0.6% and CCNC at the ground site was operated with the five different supersaturations (0.2%, 0.4%, 0.6%, 0.8%, and 1.0%). The NASA DC-8 conducted 20 research flights (about 150 hours) in and around the Korean Peninsula and the ground measurement at Olympic Park was continuously made during the measurement period. Both airborne and ground measurements showed spatially and temporally varied aerosol number concentration and CCN activity. Aerosol number concentration in the boundary layer measured on airborne platform was highly affected by pollution sources on the ground. The average diurnal distribution of ground aerosol number concentration showed distinct peaks are located at about 0800, 1500, and 2000. The middle peak indicates that new particle formation events frequently occurred during the measurement period. CCN activation ratio at 0.6% supersaturation (NCCN/NCN) of the airborne measurement ranged from 0.1 to 0.9, indicating that aerosol properties in and around the Korean Peninsula varied so much (e. g. size, hygroscopicity). Comprehensive analysis results will be shown at the conference.

A rigorous assessment of tree height measurements obtained using airborne LIDAR and conventional field methods.

Treesearch

Hans-Erik Andersen; Stephen E. Reutebuch; Robert J. McGaughey

2006-01-01

Tree height is an important variable in forest inventory programs but is typically time-consuming and costly to measure in the field using conventional techniques. Airborne light detection and ranging (LIDAR) provides individual tree height measurements that are highly correlated with field-derived measurements, but the imprecision of conventional field techniques does...

Remote Sensing of Aerosol Backscatter and Earth Surface Targets By Use of An Airborne Focused Continuous Wave CO2 Doppler Lidar Over Western North America

NASA Technical Reports Server (NTRS)

Jarzembski, Maurice A.; Srivastava, Vandana; Goodman, H. Michael (Technical Monitor)

2000-01-01

Airborne lidar systems are used to determine wind velocity and to measure aerosol or cloud backscatter variability. Atmospheric aerosols, being affected by local and regional sources, show tremendous variability. Continuous wave (cw) lidar can obtain detailed aerosol loading with unprecedented high resolution (3 sec) and sensitivity (1 mg/cubic meter) as was done during the 1995 NASA Multi-center Airborne Coherent Atmospheric Wind Sensor (MACAWS) mission over western North America and the Pacific Ocean. Backscatter variability was measured at a 9.1 micron wavelength cw focused CO2 Doppler lidar for approximately 52 flight hours, covering an equivalent horizontal distance of approximately 30,000 km in the troposphere. Some quasi-vertical backscatter profiles were also obtained during various ascents and descents at altitudes that ranged from approximately 0.1 to 12 km. Similarities and differences for aerosol loading over land and ocean were observed. Mid-tropospheric aerosol backscatter background mode was approximately 6 x 10(exp -11)/ms/r, consistent with previous lidar datasets. While these atmospheric measurements were made, the lidar also retrieved a distinct backscatter signal from the Earth's surface from the unfocused part of the focused cw lidar beam during aircraft rolls. Atmospheric backscatter can be highly variable both spatially and temporally, whereas, Earth-surface backscatter is relatively much less variant and can be quite predictable. Therefore, routine atmospheric backscatter measurements by an airborne lidar also give Earth surface backscatter which can allow for investigating the Earth terrain. In the case where the Earth's surface backscatter is coming from a well-known and fairly uniform region, then it can potentially offer lidar calibration opportunities during flight. These Earth surface measurements over varying Californian terrain during the mission were compared with laboratory backscatter measurements using the same lidar of various

30 CFR 56.5005 - Control of exposure to airborne contaminants.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Air Quality and Physical Agents Air Quality § 56.5005 Control of exposure to airborne contaminants... Administration. (c) When respiratory protection is used in atmospheres immediately harmful to life, the presence...

Mesures spectroscopiques de constituants et de polluants atmosphériques par techniques in situ et à distance, au sol ou embarquéesSpectroscopic measurements of atmospheric constituents and pollutants by in situ and remote techniques from the ground and in flight

NASA Astrophysics Data System (ADS)

Camy-Peyret, Claude; Payan, Sébastien; Jeseck, Pascal; Té, Yao

2001-09-01

Infrared spectroscopy is a powerful tool for precise measurements of atmospheric trace species concentrations through the use of characteristic spectral signatures of the different molecular species and their associated vibration-rotation bands in the mid- or near-infrared. Different methods based on quantitative spectroscopy permit tropospheric or stratospheric measurements: in situ long path absorption, atmospheric absorption/emission by Fourier transform spectroscopy with high spectral resolution instruments on the ground, airborne, balloon-borne or satellite-borne.

Characterization of Atmospheric Aerosol Behavior and Climatic Effects by Analysis of SAGE 2 and Other Space, Air, and Ground Measurements

NASA Technical Reports Server (NTRS)

Livingston, John M.

1999-01-01

This report documents the research performed under NASA Ames Cooperative Agreement NCC 2-991, which covered the period 1 April 1997 through 31 March 1999. Previously, an interim technical report (Technical Report No. 1, 20 March 1998) summarized the work completed during the period 1 April 1997 through 31 March 1998. The objective of the proposed research was to advance our understanding of atmospheric aerosol behavior, aerosol-induced climatic effects, and the remote measurement and retrieval capabilities of spaceborne sensors such as SAGE II by combining and comparing data from these instruments and from airborne and ground-based instruments.

Concentration and trend of 9,10-phenanthrenequinone in airborne particulates collected in Nagasaki city, Japan.

PubMed

Kishikawa, Naoya; Nakao, Maiko; Ohba, Yoshihito; Nakashima, Kenichiro; Kuroda, Naotaka

2006-07-01

9,10-Phenanthrenequinone (PQ), one of the components of atmospheric pollutants, has potent harmful effects on human health. PQ in airborne particulates collected in Nagasaki city was determined by HPLC with fluorescence derivatization. PQ extracted from airborne particulates using methanol was derivatized with benzaldehyde in the presence of ammonium acetate to give a fluorescent compound. The average concentration (mean+/-SD, n=52) of PQ found in airborne particulates collected from July 1997 to June 1998 was 0.287+/-0.128 ng m-3. Concentrations of PQ in winter were higher than those in summer. In a weekly variation study, PQ concentrations were higher during weekdays and lower at weekend. The levels of PQ were obviously correlated with those of phenanthrene (PH) that is considered as a parent compound of PQ. This observation suggested that PQ was emitted into the atmosphere from the same source as PH, or PQ was converted from PH in the atmosphere.

Aerosol-fluorescence spectrum analyzer: real-time measurement of emission spectra of airborne biological particles

NASA Astrophysics Data System (ADS)

Hill, Steven C.; Pinnick, Ronald G.; Nachman, Paul; Chen, Gang; Chang, Richard K.; Mayo, Michael W.; Fernandez, Gilbert L.

1995-10-01

We have assembled an aerosol-fluorescence spectrum analyzer (AFS), which can measure the fluorescence spectra and elastic scattering of airborne particles as they flow through a laser beam. The aerosols traverse a scattering cell where they are illuminated with intense (50 kW/cm 2) light inside the cavity of an argon-ion laser operating at 488 nm. This AFS can obtain fluorescence spectra of individual dye-doped polystyrene microspheres as small as 0.5 mu m in diameter. The spectra obtained from microspheres doped with pink and green-yellow dyes are clearly different. We have also detected the fluorescence spectra of airborne particles (although not single particles) made from various

Source term estimation of radioxenon released from the Fukushima Dai-ichi nuclear reactors using measured air concentrations and atmospheric transport modeling.

PubMed

Eslinger, P W; Biegalski, S R; Bowyer, T W; Cooper, M W; Haas, D A; Hayes, J C; Hoffman, I; Korpach, E; Yi, J; Miley, H S; Rishel, J P; Ungar, K; White, B; Woods, V T

2014-01-01

Systems designed to monitor airborne radionuclides released from underground nuclear explosions detected radioactive fallout across the northern hemisphere resulting from the Fukushima Dai-ichi Nuclear Power Plant accident in March 2011. Sampling data from multiple International Modeling System locations are combined with atmospheric transport modeling to estimate the magnitude and time sequence of releases of (133)Xe. Modeled dilution factors at five different detection locations were combined with 57 atmospheric concentration measurements of (133)Xe taken from March 18 to March 23 to estimate the source term. This analysis suggests that 92% of the 1.24 × 10(19) Bq of (133)Xe present in the three operating reactors at the time of the earthquake was released to the atmosphere over a 3 d period. An uncertainty analysis bounds the release estimates to 54-129% of available (133)Xe inventory. Copyright © 2013 Elsevier Ltd. All rights reserved.

Atmospheric electrical detection of organized convection.

PubMed

Markson, R

1975-06-20

Relatively simple atmospheric electrical instrumentation carried on a small aircraft constitutes a flexible and sensitive system for detecting organized convection. Data can be obtained close to the sea surface, and low-velocity flight enhances the spatial resolution. With a slow-flying airplane or powered glider, it may be possible to trace the circulation of individual convection cells and to investigate the trajectory of air which forms cumulus clouds, one of the major unsolved problems in tropical meteorology. Since space charge near the ocean surface was found on some days to be organized on a horizontal scale equivalent to the cumulus cloud scale, this suggests that some of the air which forms maritime cumulus clouds may come from within a few meters of the ocean and that atmospheric electrical instrumentation may have the potential for tracing air from the sea surface to the clouds. Although the atmospheric electrical instrumentation technique described here cannot be used for direct measurement of air velocity, it may be possible to develop model that can be used to calculate air velocities from electric field data. Even though with the technique described here it is not possible to make direct measurements of wind velocity, airborne electric field records can provide useful information about convection by delineating patterns in the wind field and structural features of thermals (rising bodies of relatively warm air) and by making possible the remote detection of thermals (29). Future plans include attempting to trace interfaces between adjacent roll vortices from the sea surface through the depth of the mixed layer (i) by flying the aircraft parallel to the wind so as to nullify the horizontal electric field (measured between wing-tip probes) while ascending and descending along the interface between adjacent roll vortices and (ii) by measuring vertical and horizontal potential gradient variations at different flight levels (30). The sensitivity of

Rapid assessment of water pollution by airborne measurement of chlorophyll content.

NASA Technical Reports Server (NTRS)

Arvesen, J. C.; Weaver, E. C.; Millard, J. P.

1971-01-01

Present techniques of airborne chlorophyll measurement are discussed as an approach to water pollution assessment. The differential radiometer, the chlorophyll correlation radiometer, and an infrared radiometer for water temperature measurements are described as the key components of the equipment. Also covered are flight missions carried out to evaluate the capability of the chlorophyll correlation radiometer in measuring the chlorophyll content in water bodies with widely different levels of nutrients, such as fresh-water lakes of high and low eutrophic levels, marine waters of high and low productivity, and an estuary with a high sediment content. The feasibility and usefulness of these techniques are indicated.

Mismatch in aeroallergens and airborne grass pollen concentrations