In this work, we present the new multi-wavelength dataset of aerosol profiles, which are retrieved from the averaged transmittance spectra by the Global Ozone Monitoring by Occultation of Stars instruments on board the Envisat satellite.
Using monthly and zonally averaged transmittances as a starting point for the retrievals allows an improved signal-to-noise ratio of elimination of possible...
Introduction: The NOMAD-UVIS instrument on board the ExoMars Trace Gas Orbiter has been investigating the Martian atmosphere with the occultation technique since April 2018 [1]. In the solar occultation mode, it is mainly devoted to study the climatology of ozone and aerosol content [2,3,4].
We analyzed almost two Mars Years of ozone vertical distributions acquired at the day-night...
Direct observations of the thermospheric state can provide direct indicators of space weather activity for constraining models of the thermosphere-ionosphere system. However, no such measurements are currently made in real-time for use in space weather operations, and few have been historically collected for research purposes.
Discussed are results from a NASA Operations to Research project...
The Atmospheric Chemistry Experiment (ACE) is comprised of a Fourier transform spectrometer (ACE-FTS) operating in the infrared with broad spectral coverage (750 – 4400 cm-1) and high resolution (0.02 cm-1), a UV-Visible-NIR spectrophotometer (ACE-MAESTRO, Measurement of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation) with wavelength coverage 280 – 1030 nm and...
Ozone and water vapor in the lower stratosphere are important trace gases for atmospheric chemistry and radiative budget. The Stratospheric Aerosol and Gas Experiment (SAGE) missions have been crucial in monitoring the stratospheric ozone loss and the subsequent recovery as well as the trends in water vapor linked to surface temperature trends. The SAGE III instrument aboard the International...
ESA's Climate Change Initiative (CCI) programme was initiated around 2010 to address the difficulties in harmonising and merging climate data records (CDR) of Essential Climate Variables (ECV) and to provide climate modellers and researchers with stable long-term time series obtained by current and past European (and third-party) satellite missions. For over a decade now, the Ozone_cci team...
The Stratospheric Water and Ozone Satellite Homogenized (SWOOSH) database is a monthly mean merged data set of vertically resolved ozone and water vapor data from a subset of limb profiling instruments operating since the 1980s. In this presentation, we summarize recent updates and improvements to SWOOSH that were made as part of the forthcoming version 3.0 release. Changes in version 3.0...
NASA’s Global Modeling and Assimilation Office is producing a new reanalysis of stratospheric composition by assimilating water vapor, hydrogen chloride, nitric acid, nitrous oxide, and ozone profiles from Aura Microwave Limb Sounder (MLS). Named M2-SCREAM (MERRA-2 Stratospheric Composition Reanalysis of Aura MLS), this product covers the period between late 2004 and the present. Global...
The MATS (Mesospheric Aerosol/Airglow Tomography and Spectroscopy) satellite was finally launched on 4 November 2022 aboard an Electron rocket from New Zealand. It entered a 585 km sun-synchronous orbit with an LTAN of 17:45. Already a few days after launch first light was seen by the instrument confirming its functionality and ability to collect the planned data.
MATS images the...
Atmospheric composition continues to be a key Earth science focus for international space agencies and research organizations. The target constituent varies depending upon the topic area of interest such as monitoring the ozone layer and the efficacy of the Montreal Protocol, assessing the influence of volcanic eruptions and large wildfires on the atmosphere, improving our knowledge of...
The composition of the Upper Troposphere and Stratosphere (UTS) plays a significant role in controlling the Earth’s climate, but there are still poorly explored feedbacks within the Earth System. This region is coupled to the surface and the free troposphere both dynamically and radiatively. Its composition is strongly affected by anthropogenic emissions of greenhouse gases (GHG) and pollution...
Fourier-transform infrared (FTIR) sounding of the thermal emission of the Earth’s atmosphere is a versatile tool to address multiple scientific questions with one single instrument. Broad spectral coverage in combination with high spectral resolution provide information on a variety of trace gases, temperature and clouds. In the last decades, airborne FTIR sounders have been deployed for...
A novel limb sounder for the measurement of temperature at the mesosphere and lower thermosphere boundary is presented. The instrument is designed to fly on Micro- and Nanosatellite platforms for the deployment in satellite constellations. The goal is to obtain a dense, 4-dimensional mesh of temperatures for resolving the small scale, time-varying waves that couple atmospheric regions....
The Changing-Atmosphere Infra-Red Tomography Explorer (CAIRT) is currently in Phase 0 as one of four candidates for ESA’s Earth Explorer 11. As a Fourier transform infrared limb imager, CAIRT will observe simultaneously from the middle troposphere to the lower thermosphere at high spectral resolution in 3D with unprecedented horizontal and vertical resolution. With this, CAIRT will provide...
The Changing-Atmosphere Infra-Red Tomography Explorer (CAIRT) is one of the four candidates for ESA’s Earth Explorer 11. This mission has been proposed in order to achieve a step change in our understanding of the coupling of atmospheric circulation, composition and regional climate. The CAIRT concept proposes to perform limb tomography of the atmosphere from the troposphere to the lower...
The Airborne Scanning Microwave Limb Sounder (A-SMLS) is an instrument designed to fly onboard the NASA ER-2 aircraft, making wide-swath vertical profile observations of the composition of the upper troposphere and lower stratosphere (~10 – 20 km altitude) at 340 GHz. Observing a ~300km-wide swath ahead of the aircraft in a 2D raster scan (azimuth and elevation), A-SMLS is designed to measure...
Characterizing the distribution and evolution of aerosol particles in the stratosphere (10-40 km altitude) is important for understanding their potential contribution to long-term climate through heating. Significant heating effects are also observed due to impulsive events such as volcanic eruptions and smoke plumes from large wildfires, which can have considerable economic consequences....
Spaceborne observations have enabled critical insights into the behavior of Earth's atmosphere. Atmospheric limb sounding (viewing the atmosphere edge-on) offers good vertical resolution, and the long atmospheric path viewed provides a strong signal to noise for measurements of tenuous trace gases. We present an overview of the “Microwave Limb Sounder” (MLS) series of instruments, whose...
The Stratospheric Aerosol and Gas Experiment (SAGE) III instrument was deployed on the International Space Station (ISS) in early March 2017 and began routine measurements in June 2017. SAGE III retrieves profiles of temperature and pressure from multi-spectral measurements of the oxygen A-band absorption feature centered near 762 nm. The A-band is located in a favorable spectral region where...
Total ozone is a measure of the protection of the biosphere from UV radiation. Extratropical total ozone recovery trends of about +0.5%/decade are consistent with the continuous decline in stratospheric halogen loading since the middle 1990s as a consequence of the Montreal Protocol and its Amendments on phasing out ODS. Nevertheless, the recovery (or chemistry-related) trends in the northern...
Stratospheric ozone absorbs ultraviolet radiation that is harmful to life on earth. Ozone is a major driving force of atmospheric dynamic processes and is responsible for the radiative heating of the stratosphere. Due to anthropogenic emissions of ozone-depleting substances (ODS) the amount of
stratospheric ozone decreased substantially through the latter part of the 20th century and the...
The detection of random transients, arising from high energy particle hits on CCD pixels, bears significance for the OMPS Limb Profiler (LP) sensor and other limb scatter sensors of similar design. This is because majority of the LP science data products are derived from altitude normalized radiances where even small transients at normalization altitude can be significant. Results from a...
The combined effect of El Niño-Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD)on the tropical Upper Troposphere Lower Stratosphere (UTLS) ozone is examined using the data from Microwave Limb Sounder (MLS) onboard Aura Satellite and ECMWF (European Centre for Medium-Range Weather Forecasts) ERA5 reanalysis. During the years of positive (negative) ENSO and IOD events, UTLS ozone mixing...
The Ozone Mapping and Profiler Suite’s Limb Profiler (OMPS-LP), built by Ball Aerospace, is a dedicated imaging spectrograph for measuring vertical ozone profiles. Two Limb Sensors are currently in orbit aboard the Suomi NPP and JPSS-2 (now NOAA-21) spacecraft with two more units slated to fly aboard JPSS-3 and JPSS-4. The Limb sensor measures the vertical distribution of ozone in the...
This presentation describes recent updates to the Gauss Seidel Limb Scattering (GSLS) radiative transfer model, and provides a preliminary assessment of the impact of those updates on the NASA OMPS LP aerosol extinction coefficient retrieval algorithm. This work builds upon the most recently-released aerosol extinction data product (Version 2.1), which provides retrievals at several...
Sulfur hexafluoride (SF$_6$) is a greenhouse gas that is emitted at the surface because of its use as an insulator in electrical transmission equipment and electronic devices. Since its quasi-linear emission growth and its very long lifetime, SF$_6$ can be used as a tracer for the Age of Air (AoA) to diagnose changes in the Brewer Dobson Circulation (BDC). The chemistry of SF$_6$ has been...
LOTUS (Long-term Ozone Trends and Uncertainties in the Stratosphere) is a SPARC (Stratosphere-troposphere Processes And their Role in Climate)-sponsored effort to foster collaboration between established and early career scientists around the world, with expertise in ozone observations, modeling, and trend tools, with an aim toward innovating new climate research that meets the needs of the...
The Limb Profiler (LP) instrument, part of the Ozone Mapper and Profiler (OMPS) Suite, is designed to measure ozone and aerosol vertical profiles in the stratosphere and to continue long-term ozone data records. The first OMPS LP instrument has been operating on the Suomi National Polar-orbiting Partnership (SNPP) satellite since 2012 and the second LP instrument on the NOAA-21 satellite was...
The OSIRIS instrument has now operated for over 20 years beyond its original two year lifetime and there are no technical reasons why it will not continue to operate for at least the next few years. The Team associated with this Canadian built instrument was part of the initial consortium of scientists that pioneered the concept of these ongoing Limb Workshops. This presentation will summarize...
The SASKTRAN radiative transfer model has been used for over twenty years in the retrieval processes associated with the Canadian OSIRIS instrument in operation onboard the Swedish spacecraft Odin. It started as a single Rayleigh scatter model first developed in the mid-1990s and has evolved into something much more. This presentation will detail the latest SASKTRAN developments that make it...
During the twilight event the boundary between the illuminated and shadowed parts of the atmosphere shifts upward with the increasing solar zenith angle. This makes it possible to retrieve the vertical profile of aerosol extinction from the ground – based measurements of the twilight sky brightness as a function of the solar zenith angle, performed in a narrow field of view and a narrow...
The quasi-biennial oscillation (QBO) represents a significant component of atmospheric dynamic variability in the stratosphere. Disruptions in the regular, if complex, nature of the QBO observed beginning in 2015 have reduced the power of traditional modeling approaches using linear dimensionality reduction techniques, e.g. principal component analysis (PCA). While the use of additional...
The Atmospheric Chemistry Experiment`– Fourier Transform Spectrometer (ACE-FTS) is a high spectral resolution spectrometer on the SciSat satellite that has been taking solar occultation measurements of the Earth’s limb since February 2004. ACE-FTS measures vertical profiles of temperature/pressure and concentrations of over 60 trace gases, including ozone and water vapour, with a vertical...
Both satellite observations and model simulations have shown ozone recovery since late 1990s. It is less certain for ozone in the mid-latitude lower stratosphere, where merged satellite observations suggest small decreases for 2000-2020, while Chemistry Climate Models (CCMs) suggest small increases (WMO, 2022). The differences could result from uncertainties in merged satellite data sets...
Uncertainties in observations often considerably limit our ability to assess long-term changes in the vertical distribution of water vapour. ESA's Climate Change Initiative (CCI) was set up to address the difficulties in harmonizing and merging climate data records (CDRs) of key climate variables and to provide climate modellers and researchers with high-quality, stable, long-term time series...
We present the calculation of ozone trends from various versions of combined satellite records SAGE II, MIPAS and OMPS NASA, which spans the period from 1979 to 2022. The merging is performed using different transfer standards: satellite records of ACE-FTS and MLS, and model runs EMAC, CMAM and WACCM. The impact of transfer standard on corresponding trends is investigated.
NOAA’s goal of understanding climate change is supported by operations of satellite and ground-based ozone observations that allow monitoring of atmospheric composition variability and long-term changes in the stratosphere and troposphere. Both satellite and ground-based (GB) observations are needed to track stratospheric ozone recovery and to evaluate the atmospheric radiative budget. Both GB...
Rising greenhouse gas emissions are changing the circulation in the stratosphere and subsequently altering the stratospheric composition. The result is that trace gas trends from the past two decades show a hemispheric asymmetry, with trends in each hemisphere having opposite signs. Here we discuss trends in observations from the limb instruments ACE-FTS and OSIRIS, as well as trends in model...
We present trace gas and aerosol measurements obtained by the airborne infrared imaging limb sounder GLORIA (Gimballed Limb Observer for Radiance Imaging of the Atmosphere) that has been operated onboard the research aircraft Geophysica within the Asian Monsoon during the StratoClim campaign (July 2017) and onboard HALO (High Altitude and Long Range Research Aircraft) above the South Atlantic...
In August 2023, the Canadian-led Atmospheric Chemistry Experiment (ACE) mission will complete its 20th year in orbit on board the SCISAT satellite. The long lifetime of ACE provides a valuable time series of composition measurements that contribute to our understanding of ozone recovery, climate change and pollutant emissions. The main instruments on board SCISAT use infrared and UV-visible...
Since the mid-1980s, a series of limb and occultation instruments provide observations to assess past and recent changes in stratospheric ozone. Long-term changes are so small that the stability of the ozone profile climate data records (CDRs) must be better than ~2% per decade in order to be detected. Ensuring this level of stability poses a challenge for the teams providing datasets of...
We report the results of validation exercise of ozone and temperature L2 MIPAS products, processed with IMK/IAA Level 2 scientific processor. Ozone profiles are compared to ACE-FTS, MLS, GOMOS, OSIRIS and SAGE II records, as well as to ozonesondes records from HEGIFTOM database.
Temperature profiles are compared to ACE-FTS, MLS and HALOE satellite records, GRUAN profiles, and COSMIC and...
ALTIUS is a limb sounder mission that for the monitoring of the distribution and evolution of stratospheric ozone at high vertical resolution in support of operational services and long term trend monitoring. The ALTIUS mission will provide detailed stratospheric ozone profiles information at high vertical resolution, which adds valuable information to total column ozone used for data...
ALTIUS has been accepted as an Earth Watch mission with the primary objective of measuring concentration profiles of ozone in the stratosphere. But the mission has secondary scientific objectives which, however, are not driving the space segment developments. Recognizing that the instrumental concept of ALTIUS is offering opportunities for measuring at wavelengths relevant for other...
In-flight calibration techniques developed for ALTIUS at the University of Saskatchewan are presented. Simulated observations of the Sun, Moon and high-altitude atmosphere are used to measure instrument photo-response non-uniformity, spatial point spread function, wavelength registration and polarization response. The performance of the simulated techniques is assessed.
Based on highly autonomous and pointing-agile PROBA-NEXT Platform, the ALTIUS satellite embarks an optical instrument made of three independent channels (VIS, UV and NIR) to observe the Earth limb through a field of view of 100 km x 100 km, measuring scattered sun light (bright limb) and atmospheric attenuation (solar and stellar occultation mode) in fully tuneable monochromatic 2-D...
Programmed as an element of ESA’s Earth Watch programme, Atmospheric Limb Tracker for Investigation of the Upcoming Stratosphere (ALTIUS) has been developed as a gap filler mission responding to the urgent need to continue the global, long-term monitoring of stratospheric ozone, other trace gases and aerosols at the vertical resolution of the order of a few km. Scheduled for operation in the...
The Limb Profiler (LP) is a part of the Ozone Mapping and Profiler Suite on the Suomi NPP satellite. We present a new version of the ozone profile product processed at NASA Goddard Space Flight Center (GSFC). In this study we summarize changes implemented in version 2.6 including changes in both Level 1 and Level 2 algorithms. In this presentation we focus on algorithmic Level 2 changes. The...
Nadir near-UV measurements are used routinely to derive aerosol optical depth and single scattering albedo of desert dust and carbonaceous aerosols. Accurate retrieval of these parameters, however, requires aerosol layer height (ALH) information. Over dark vegetated-land and water surfaces, ALH can be retrieved using Oxygen A and B band observations from sensors equipped with those...
Stratospheric aerosols largely affect the radiative budget of the Earth’s atmosphere by scattering the incident solar radiation back to the space in the UV-Vis-NIR spectral range and by absorbing the radiation upwelling from the troposphere in the thermal infrared spectral range. Furthermore, stratospheric aerosols provide surface for heterogeneous reactions releasing halogenated compounds,...
The Aerosol Limb Imager (ALI) is a multi-spectral polarimetric imager designed to observe scattered sun light in the limb. ALI collects images in a narrow spectral band in one of two orthogonal polarization states for the purpose of retrieving aerosol number density and particle size information within the upper-troposphere lower-stratosphere. Of novelty is the polarimetric nature of the...
Retrieval artifacts from 1D limb retrievals, which assume homogeneous atmospheric properties along the satellite line of sight (LOS), are known but generally associated with variations in the trace gas concentration or temperature. The focus of this study is the investigation of a retrieval artifact identified in tropospheric ozone data and ozone limb profiles retrieved from OMPS-LP...
In this study we demonstrate how neural network (NN) models can be used to improve our understanding of OMPS LP measurements, optimize forward modeling, and enhance OMPS LP retrievals. Retrieving atmospheric profiles from limb observations requires modeling how solar light scatters through the atmosphere. Operational retrieval codes make approximations for computationally expensive processes...
We report on the detection and upper-limit of SO$_2$, SO$_3$, OCS, H$_2$S, CS, H$_2$CO, O$_3$, NH$_3$, HCN, N$_2$O, NO$_2$, and HO$_2$ above the cloud deck using the SOIR instrument on-board Venus Express [1, 2].
The SOIR instrument [3] performed solar occultation measurements in the IR region (2.2 - 4.3 µm) at a spectral resolution of 0.12 cm$^{-1}$, among the highest of all space...
The Changing-Atmosphere Infra-Red Tomography Explorer (CAIRT) is one of the four candidates for ESA’s Earth Explorer 11. By exploiting its imaging capabilities, CAIRT can sound the atmosphere simultaneously from the middle troposphere to the lower thermosphere at high spectral resolution and with unprecedented horizontal and vertical resolution. Flying in loose formation with MetOp-SG mission...
Aerosols are present in the atmosphere of Mars and have a major effect on it. They are mainly composed of dust, water ice and CO2 ice. Dust is confined to lower altitudes during the aphelion season and can reach higher altitudes during the perihelion, especially during dust storms that frequently arise on Mars. These storms can sometimes grow up to cover the entire planet and are then called...
The data record of the Aura Microwave Limb Sounder (MLS) currently covers more than 18 years, far exceeding its original 5-year design life. As part of the A-train constellation, the long MLS data record and the comparatively high spatio-temporal resolution of its retrieval products provide a unique opportunity to apply machine learning techniques to enhance its observational...
The Changing-Atmosphere Infra-Red Tomography Explorer (CAIRT) is one of four candidates for ESA’s Earth Explorer 11. It's imaging capabilities will be used to offer several independent measurement tracks across its swath and thus deliver, in combination with tomographic retrieval techniques, a true 3-D product with a high vertical resolution (down to 1km).
In this work, we will examine and...
AerGOM is a retrieval algorithm that was specifically designed to retrieve stratospheric aerosol extinction from the Global Ozone Monitoring by the Occultation of Stars (GOMOS) experiment that was launched onboard Envisat and provided measurements of the Earth atmospheric limb between 2002 and 2012.
While AerGOM retrieves simultaneously aerosol extinction, ozone, nitrogen dioxide and...
The Earth’s hydrogen (H) corona has been observed from various platforms for over half a century and many of these measurements, particularly those made in recent times, leverage the observation of solar H-Lyman-α (121.6 nm) photons resonantly scattered by H. Interpreting these observations becomes increasingly complex in the optically thick region of the corona below 3 Earth-radii (RE) where...
The study of Jupiter’s atmosphere is of interest to the scientific community, including its composition, evolution, distribution, structure, and dynamics around the planet. Although the main chemical composition of Jupiter’s atmosphere has been unraveled, many questions remain open, such as the global abundance of water, or the responsible chemistry for the coloration of the clouds....
To monitor stratospheric ozone and aerosols, the ALTIUS mission will perform measurements either in limb scattering mode or in occultation mode. In this mode, the satellite will observe the Sun during sunrise and sunset, and the rises and sets of the brightest stars and planets during the night. To increase the geographic coverage of the observations, lunar measurements will also be carried...
The Stratospheric Aerosol and Gas Experiment III (SAGE III) is an externally affixed payload on the International Space Station (ISS; SAGE III/ISS). SAGE III/ISS retrieves highly resolved vertical profiles of gaseous atmospheric constituent number density including ozone, water vapor, and nitrogen dioxide, as well as aerosol extinction coefficient at nine wavelengths in the visible to near-IR...
Polar stratospheric clouds (PSC) play an important role in polar ozone loss. However, there are still gaps in our knowledge about PSCs and nitric acid trihydrate (NAT) particles in particular. Active lidar and passive limb emission satellite instruments allow for PSC measurements over the entire winter season at both poles and provide a classification between the three types: ice, NAT, and...
Solar radiation management has been proposed as a method to combat and control changes in the climate of Earth. The method aims at the intentional releasing of aerosol into the atmosphere to adjust radiative forcing. However, there is significant uncertainty in the evolution of artificial aerosol particles, as well as the atmospheric dynamics of such a release. The Stratospheric Controlled...
Stratospheric aerosols play key roles in the chemistry and radiation balance of the atmosphere and are a key input parameter for global chemistry and climate models. The degree to which aerosols impact chemistry and radiation balance depends primarily on the relative abundance of different sized particles within the sample volume, often referred to as the particle size distribution (PSD). If...
On 15 January 2022, the submarine Hunga Tonga-Hunga Ha'apai volcanic eruption lofted materials high into the upper stratosphere, reaching a record-breaking altitude of ~58 km, unprecedented in the satellite observations era. Within two weeks, the bulk of the injected material circulated the globe between 20 – 30 km altitude, as observed by the OMPS LP instrument. Initial predictions suggested...
The 2022 eruption of the Hunga Tonga-Hunga Ha’apai volcano caused substantial impacts on the atmosphere, including a large increase of stratospheric aerosol at high altitudes and a massive injection of water vapor. We show results from application of a two-dimensional tomographic retrieval of aerosol extinction profiles from limb scattered sunlight made by the NASA OMPS Limb Profiler...
Climate-related studies need information about the distribution of stratospheric aerosols, which impact the energy balance of the Earth’s atmosphere. In this work, we present a merged dataset of vertically resolved stratospheric aerosol extinction coefficients, which is derived from data by six limb and occultation satellite instruments: SAGE II on ERBS, GOMOS and SCIAMACHY on Envisat, OSIRIS...
The Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) is a limb-imaging Fourier-Transform spectrometer (iFTS) providing mid-infrared spectra with high spectral resolution (0.0625 cm-1 in the wavelength range 780-1400 cm-1). GLORIA, a demonstrator for the Changing-Atmosphere Infra-Red Tomography Explorer (CAIRT, one of the candidates selected for Phase 0 for the ESA Earth...
