trace species
Recently Published Documents


TOTAL DOCUMENTS

300
(FIVE YEARS 31)

H-INDEX

41
(FIVE YEARS 4)

2021 ◽  
Vol 14 (12) ◽  
pp. 7975-7998
Author(s):  
Bianca Maria Dinelli ◽  
Piera Raspollini ◽  
Marco Gai ◽  
Luca Sgheri ◽  
Marco Ridolfi ◽  
...  

Abstract. The observations acquired during the full mission of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instrument, aboard the European Space Agency Environmental Satellite (Envisat), have been analysed with version 8.22 of the Optimised Retrieval Model (ORM), originally developed as the scientific prototype of the ESA level-2 processor for MIPAS observations. The results of the analyses have been included into the MIPAS level-2 version 8 (level2-v8) database containing atmospheric fields of pressure, temperature, and volume mixing ratio (VMR) of MIPAS main targets H2O, O3, HNO3, CH4, N2O, and NO2, along with the minor gases CFC-11, ClONO2, N2O5, CFC-12, COF2, CCl4, CF4, HCFC-22, C2H2, CH3Cl, COCl2, C2H6, OCS, and HDO. The database covers all the measurements acquired by MIPAS in the nominal measurement mode of the full resolution (FR) part of the mission (from July 2002 to March 2004) and all the observation modes of the optimised resolution (OR) part (from January 2005 to April 2012). The number of species included in the MIPAS level2-v8 dataset makes it of particular importance for the studies of stratospheric chemistry. The database is considered by ESA the final release of the MIPAS level-2 products. The ORM algorithm is operated at the vertical grid coincident to the tangent altitudes of the observations or to a subset of them, spanning (in the nominal mode) the altitude range from 6 to 68 km in the FR phase and from 6 to 70 km in the OR period. In the latitude domain, FR profiles are spaced by about 4.7∘, while the OR profiles are spaced by about 3.7∘. For each retrieved species, the auxiliary data and the retrieval choices are described. Each product is characterised in terms of the retrieval error, spatial resolution, and “useful” vertical range in both phases of the MIPAS mission. These depend on the characteristics of the measurements (spectral and vertical resolution of the measurements), the retrieval choices (number of spectral points included in the analyses, number of altitudes included in the vertical retrieval grid), and the information content of the measurements for each trace species. For temperature, water vapour, ozone, and nitric acid, the number of degrees of freedom is significantly larger in the OR phase than in the FR one, mainly due to the finer vertical measurement grid. In the FR phase, some trace species are characterised by a smaller retrieval error with respect to the OR phase, mainly due to the larger number of spectral points used in the analyses, along with the reduced vertical resolution. The way of handling possible caveats (negative VMR, vertical grid representation) is discussed. The quality of the retrieved profiles is assessed through four criteria, two providing information on the successful convergence of the retrieval iterations, one on the capability of the retrieval to reproduce the measurements, and one on the presence of outliers. An easy way to identify and filter the problematic profiles with the information contained in the output files is provided. MIPAS level2-v8 data are available to the scientific community through the ESA portal (https://doi.org/10.5270/EN1-c8hgqx4).


2021 ◽  
Author(s):  
Alexandra Laeng ◽  
Thomas von Clarmann ◽  
Quentin Errera ◽  
Udo Grabowski ◽  
Shawn Honomichl

Abstract. High-resolution model data are used to estimate typical variabilities of mixing ratios of trace species as a function of spatial and temporal distance. These estimates can be used to explain that part of the differences between observations made with different observing systems that are due to less than perfect collocation of the measurements. The variability values are described by a two-parameter regression function. A reparametrization of the variabilities values as function of latitudinal graidents is proposed, and season-independence of linear approximation of such function is demonstrated.


2021 ◽  
Vol 14 (10) ◽  
pp. 6795-6819
Author(s):  
Eric J. Hintsa ◽  
Fred L. Moore ◽  
Dale F. Hurst ◽  
Geoff S. Dutton ◽  
Bradley D. Hall ◽  
...  

Abstract. UCATS (the UAS Chromatograph for Atmospheric Trace Species) was designed and built for observations of important atmospheric trace gases from unmanned aircraft systems (UAS) in the upper troposphere and lower stratosphere (UTLS). Initially it measured major chlorofluorocarbons (CFCs) and the stratospheric transport tracers nitrous oxide (N2O) and sulfur hexafluoride (SF6), using gas chromatography with electron capture detection. Compact commercial absorption spectrometers for ozone (O3) and water vapor (H2O) were added to enhance its capabilities on platforms with relatively small payloads. UCATS has since been reconfigured to measure methane (CH4), carbon monoxide (CO), and molecular hydrogen (H2) instead of CFCs and has undergone numerous upgrades to its subsystems. It has served as part of large payloads on stratospheric UAS missions to probe the tropical tropopause region and transport of air into the stratosphere; in piloted aircraft studies of greenhouse gases, transport, and chemistry in the troposphere; and in 2021 is scheduled to return to the study of stratospheric ozone and halogen compounds, one of its original goals. Each deployment brought different challenges, which were largely met or resolved. The design, capabilities, modifications, and some results from UCATS are shown and described here, including changes for future missions.


2021 ◽  
Author(s):  
Andrew M. Bradley ◽  
Peter A. Bosler ◽  
Oksana Guba

Abstract. Advection of trace species (tracers), also called tracer transport, in models of the atmosphere and other physical domains is an important and potentially computationally expensive part of a model's dynamical core (dycore). Semi-Lagrangian (SL) advection methods are efficient because they permit a time step much larger than the advective stability limit for explicit Eulerian methods. Thus, to reduce the computational expense of tracer transport, dycores often use SL methods to advect passive tracers. The class of interpolation semi-Lagrangian (ISL) methods contains potentially extremely efficient SL methods. We describe a set of ISL bases for element-based transport, such as for use with atmosphere models discretized using the spectral element (SE) method. An ISL method that uses the natural polynomial interpolant on Gauss-Legendre-Lobatto (GLL) SE nodes of degree at least three is unstable on the test problem of periodic translational flow on a uniform element grid. We derive new alternative bases of up to order of accuracy nine that are stable on this test problem; we call these the Islet bases. Then we describe an atmosphere tracer transport method, the Islet method, that uses three grids that share an element grid: a dynamics grid supporting, for example, the GLL basis of degree three; a physics grid with a configurable number of finite-volume subcells per element; and a tracer grid supporting use of our Islet bases, with particular basis again configurable. This method provides extremely accurate tracer transport and excellent diagnostic values in a number of validation problems. We conclude with performance results that use up to 27,600 NVIDIA V100 GPUs on the Summit supercomputer.


2021 ◽  
Author(s):  
Bianca Maria Dinelli ◽  
Piera Raspollini ◽  
Marco Gai ◽  
Luca Sgheri ◽  
Marco Ridolfi ◽  
...  

Abstract. The observations acquired during the full mission of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instrument, on board the European Space Agency ENVISAT satellite, have been analysed with version 8.22 of the Optimised Retrieval Model (ORM), originally developed as the scientific prototype of the ESA level 2 processor for MIPAS observations. The results of the analyses have been included into the MIPAS level 2 version 8 (level2-v8) database containing atmospheric fields of pressure, temperature and volume mixing ratio of MIPAS main targets H2O, O3, HNO3, CH4, N2O, and NO2, along with the minor gases CFC-11, ClONO2, N2O5, CFC-12, COF2, CCl4, CF4, HCFC-22, C2H2, CH3Cl, COCl2, C2H6, OCS, HDO. The database covers all the measurements acquired by MIPAS in the nominal measurement mode of the Full Resolution (FR) part of the mission (from July 2002 to March 2004) and all the observation modes of the Optimised Resolution (OR) part (from January 2005 to April 2012). The number of species included in the MIPAS level2-v8 data-set makes it of particular importance for the studies of stratospheric chemistry. The database is considered by ESA the final release of the MIPAS level 2 products. The ORM algorithm is operated at the vertical grid coincident to the tangent altitudes of the observations or to a subset of them, spanning (in the nominal mode) the altitude range from 6 to 68 km in the FR phase and from 6 to 70 km in the OR period. In the latitude domain, FR profiles are spaced by about 4.7 degrees while the OR profiles are spaced by about 3.7 degrees. For each retrieved species the auxiliary data and the retrieval choices are described. Each product is characterised in terms of the retrieval error, spatial resolution, and 'useful' vertical range in both phases of the MIPAS mission. These depend on the characteristics of the measurements (spectral and vertical resolution of the measurements), on the retrieval choices (number of spectral points included in the analyses, number of altitudes included in the vertical retrieval grid), and on the information content of the measurements for each trace species. For temperature, water vapour, ozone and nitric acid the number of degrees of freedom is significantly larger in the OR phase than in the FR one, mainly due to the finer vertical measurement grid. In the FR phase some trace species are characterised by a smaller retrieval error with respect to the OR phase, mainly due to the larger number of spectral points used in the analyses, along with the reduced vertical resolution. The way of handling possible caveats (negative VMR, vertical grid representation) is discussed. The quality of the retrieved profiles is assessed through four criteria, two providing information on the successful convergence of the retrieval iterations, one on the capability of the retrieval to reproduce the measurements, and one on the presence of outliers. An easy way to identify and filter the problematic profiles with the information contained in the output files is provided. MIPAS level2-v8 data are available to the scientific community through the ESA portal https://earth.esa.int/eogateway/.


2021 ◽  
Author(s):  
Xinting Yu ◽  
Julianne Moses ◽  
Jonathan Fortney ◽  
Xi Zhang
Keyword(s):  

2021 ◽  
Author(s):  
James Abshire ◽  
Scott Guzewich ◽  
Daniel Cremons ◽  
Michael Smith ◽  
Kenji Numata ◽  
...  

<p>The planetary boundary layer (PBL) is the lowest layer of the atmosphere that interacts directly with the surface. For Mars and Titan, processes within the PBL are very important scientifically because they control the transfer of heat, momentum, dust, water, and other constituents between surface and atmospheric reservoirs. For Mars understanding these processes is critical for understanding the modern climate, including the stability and development of the polar caps how the regolith exchanges with the atmosphere how wind shapes the landscape how dust is lifted and transported and for being able to validate and improve general circulation models (GCMs). The PBL is also critical for operations since it is the environment in which landed missions must operate.</p> <p>On Mars the PBL depth varies between roughly 1 and 10 km, depending on time of day, with the deepest layer occurring during the day when convective turbulence is greatest. The PBL is difficult to observe from orbit, and so detailed observations of it have been mostly limited to those just at the surface from landers. The lack of PBL observations has led to significant gaps of understanding in several key areas. These include diurnal variations of aerosols, water vapor and direct measurements of wind velocity, the combination of which provides information on the horizontal and vertical transport of water, dust, and other trace species and their exchange with the surface. The Mars atmosphere has complex interactions between its dust, water and CO<sub>2</sub> cycles. Because these quantities are interrelated and they partially drive the wind fields, it is important to measure the water vapor, aerosols, and winds simultaneously, ideally using a single instrument.</p> <p>We are developing and plan to demonstrate a breadboard of small, highly capable atmospheric lidar to address these needs for a future lander on Mars or Titan. The lidar is designed to measure vertically-resolved profiles of water vapor by using a single frequency laser. The laser will be tuned onto and off strong isolated water vapor lines near 1911 nm. The vertical distribution of water vapor will be determined from the on- and off-line backscatter profiles via the differential absorption lidar (DIAL) technique. The same laser is used for measuring aerosol and wind profiles via the Doppler shift in the backscatter. The laser beam is linearly polarized and a cross polarized receiver allows separating the backscatter of water ice from dust.  It emits two beams that are offset 30 deg from zenith and perpendicular to one another in azimuth, allowing directional wind profiles to be resolved. Both lidar measurement channels are otherwise identical and use common lens-type receiver telescopes.</p> <p>These lidar measurements address important science needs that are traceable to Mars Exploration Program Analysis Group (MEPAG) science goals relating to climate, surface-atmosphere interactions, and preparing for human exploration.  Our lidar will measure vertical profiles of water vapor, and dust and water ice aerosols and winds with km-scale vertical resolution from the surface to > 15 km altitude.  These measurements will directly profile the full planetary boundary layer, which is key for understanding how water, dust, CO<sub>2</sub> and trace species exchange between surface and atmosphere.  The lidar will provide observations of all quantities simultaneously. </p> <p>Only one atmospheric lidar has been previously flown on a planetary lander. The lidar on the Phoenix Mars lander mission (Komguem et al., 2013) successfully measured aerosol backscatter profiles at 1064 nm and 532 nm as a function of altitude and time (Whiteway, et al., 2008). The lidar also measured cloud and ice scattering profiles and measured falling ice over the Phoenix Lander site (Whiteway, 2009).</p> <p>Our lidar approach is designed to provide several important new capabilities. It will measure, for the first time, water vapor profiles from 100 m to 15 km, along with wind and aerosol profiles at 1911 nm. Our approach utilizes a highly sensitive HgCdTe avalanche photodiode detector as a key component of the lidar receiver. During the next 2 years of this project, our plan is to develop the remaining lidar components from TRL 2 to 4, and to use the breadboard lidar to demonstrate profile measurements of aerosols, water vapor and wind from the Mauna Kea Hawaii astronomy site</p> <p><em>Acknowledgement:</em> This work is supported by an award from the 2019 NASA PICASSO program.</p>


2021 ◽  
Vol 914 (1) ◽  
pp. 38
Author(s):  
Xinting Yu ◽  
Julianne I. Moses ◽  
Jonathan J. Fortney ◽  
Xi Zhang
Keyword(s):  

2021 ◽  
Author(s):  
Lin He ◽  
Erik Hans Hoffmann ◽  
Andreas Tilgner ◽  
Hartmut Herrmann

<p>Biomass burning (BB) is a significant contributor to air pollution on global, regional and local scale with impacts on air quality, public health and climate. Anhydrosugars (levoglucosan, mannosan and galactocan) and methoxyphenols (guaiacol, creosol, etc.) are important tracer compounds emitted through biomass burning. Once emitted, they can undergo complex multiphase chemistry in the atmosphere contributing to secondary organic aerosol formation. However, their chemical multiphase processing is not yet well understood and investigated by models. Therefore, the present study aimed at a better understanding of the multiphase chemistry of these BB trace species by means of detailed model studies with a new developed detailed chemical CAPRAM biomass burning module (CAPRAM-BB). This module was developed based on the kinetic data from the laser flash photolysis measurements in our lab at TROPOS and other literature studies. The developed CAPRAM-BB module includes 2991 reactions (thereof 9 phase transfers and 2982 aqueous-phase reactions). By coupling with the multiphase chemistry mechanism MCMv3.2/CAPRAM4.0 and the extended CAPRAM aromatics (CAPRAM-AM1.0) and halogen modules (CAPRAM-HM3.0), it is being applied for some residential wood burning cases in Europe and wildfire cases in the US. Our model results show that the BB chemistry could significantly affect the budgets of important atmospheric oxidants such as H<sub>2</sub>O<sub>2</sub> and HONO, and contribute to the SOA formation especially the fraction of brown carbon and substituted organic acids.</p>


2021 ◽  
Author(s):  
Christiane Voigt ◽  
Jos Lelieveld ◽  
Hans Schlager ◽  
Johannes Schneider ◽  
Daniel Sauer ◽  
...  

<p>Worldwide regulations to control the COVID-19 pandemic caused significant reductions in ground and airborne transportation in spring 2020. This unprecedented situation provided the unique opportunity to directly measure the less perturbed atmosphere, notably near the tropopause, and derive the effects of anthropogenic emissions on atmospheric composition, aerosol, clouds and climate. These changes were investigated during the BLUESKY experiment by the two research aircraft HALO and the DLR Falcon, satellite observations and models. From 16 May to 9 June 2020, the two research aircraft performed 20 flights over Europe and the North Atlantic. Profiles of trace species were measured with an advanced in-situ trace gas, aerosol and cloud payload from the boundary layer to 14 km altitude. Here, we present an overview and selected highlights of the BLUESKY experiment. Continental aerosol profiles show significant reductions in aerosol mass in the boundary layer. The reduced aerosol optical thickness above Germany has also been detected by MODIS and its impact on the colour of the sky is investigated. A specific focus was the detection of aerosol and cirrus changes caused by up to 90% reductions in air traffic. We find reductions in fine mode aerosol in the UTLS at various levels compared to CARIBIC data. In addition, we derive reductions in contrail and cirrus cover using passive and active remote sensing from satellite combined with cloud modeling. The comprehensive data set acquired during the 2020 lockdown period allows better understanding and constraining the anthropogenic influence on the composition of the atmosphere and its impacts on air quality and climate.</p>


Sign in / Sign up

Export Citation Format

Share Document