MATS (Mesospheric airglow/Aerosol Tomography and Spectroscopy) is a Swedish satellite launched in November 2022. It is a limb imager that observes $\mathrm{O_2}$ A-band airglow (four different spectral channels) in near-infrared and UV light scattered from noctilucent clouds (two channels) in the 70 km to 110 km altitude range. The airglow observations can be used to obtain a 3-D tomographic...
Stratospheric water vapor (SWV) plays an important role in atmospheric chemistry and dynamics. The Aura Microwave Limb Sounder (MLS) instrument has provided a daily near-global record of SWV for around two decades. After the Aura mission ends later this year, SWV measurements will be mostly limited to occultation measurements by the Stratospheric Aerosol and Gas Experiment III (SAGE III) and...
Due to its long time series and dense spatial coverage, the aerosol extinction coefficient (Ext) obtained from OMPS limb scattering observations is a valuable data record for observing the temporal aerosol evolution in the stratosphere after strong volcanic eruptions and wildfires. The OMPS limb scattering data set is a promising candidate for use in GLOSSAC and already used in CREST climate...
The stratospheric polar vortex varies in strength and spatial characteristics during winter in the Northern Hemisphere. If the polar vortex is shifted towards the equator as a result of breaking planetary waves, air masses from the subtropics can be transported towards the pole in so-called tropical-subtropical streamers. These large-scale structures are areas of low potential vorticity and...
ALTIUS (Atmospheric Limb Tracker for the Investigation of the Upcoming Stratosphere) is an atmospheric limb mission being implemented in ESA's Earth Watch program and planned for launch in 2027.
The instrument consists of three imagers: UV (250-355 nm), VIS (440-675 nm) and NIR (600-1040 nm) channels. Each channel is able to take a snapshot of the scene independently of the other two...
The Atmospheric Limb Tracker for the Investigation of the Upcoming Stratosphere (ALTIUS) is the European Space Agency’s (ESA) future ozone mission, part of ESA’s Earth Watch Programme. The mission is set to launch in 2027 from Kourou, aboard the Vega-C launcher.
ALTIUS is designed to perform measurements in various geometries to optimize global coverage. This includes observing...
The most recent ACE-FTS version 5.3 data for CFC-11, CFC-12 and HCFC-22 are compared with the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) version 8 data for these species, processed by the IMK/IAA (Institut für Meteorologie und Klimaforschung/Instituto de Astrofísica de Andalucía) for 2005 - 2012 . Comparisons of these two datasets are carried out for the time series of...
Due to its high spatio-temporal sampling coverage, the aerosol extinction coefficient (Ext) obtained from OMPS Limb scattering observations is excellently suited for observing the temporal aerosol evolution in the stratosphere after strong volcanic eruptions and wildfires. The record of Ext has been recently improved by the University of Bremen (UB), successfully validated with SAGE III/ISS...
The 2022 eruption of the submarine Hunga volcano injected an unprecedented amount of water vapor directly into the stratosphere. In this talk, we use measurements of gas-phase constituents from the Aura Microwave Limb Sounder (MLS) and the Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS), aerosol from the Suomi-NPP Ozone Mapping and Profiler Suite Limb Profiler...
We present an intercomparison of the mean age of air (AoA) derived from three recent reanalyses: the European Centre for Medium-Range Weather Forecasts Reanalysis version 5 (ERA5) and its predecessor (ERA-Interim), the National Aeronautics and Space Administration’s Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA2), and the Japan Meteorological Agency’s...
The Brewer-Dobson Circulation (BDC), stratospheric global mass circulation, influences the distribution of trace elements in the stratosphere, particularly radiatively active water vapour and ozone. The stratospheric meridional transport responds to various oscillations in the stratosphere, notably the tropical Quasi-Biennial Oscillation (QBO) and El Niño–Southern Oscillation (ENSO). QBO...
In January 2022, the Hunga Tonga - Hunga Ha’apai volcano emitted approximately 150 Tg H2O into the middle atmosphere. This water vapour reached the upper polar mesosphere in the Southern Hemisphere in the beginning of 2024 and increased the H2O mixing ratio in January by about 1 ppmv between 70°S - 80°S up to an altitude of 83 km. However, no clear perturbations were found in the noctilucent...
Polar winter descent of NOy produced by energetic particle precipitation (EPP) in the mesosphere and lower thermosphere affects polar stratospheric ozone by catalytic reactions. This, in turn, may affect regional climate via radiative and dynamical feedbacks. NOy observations by MIPAS/Envisat during 2002--2012 have provided observational constraints on the solar-activity modulated variability...
GSAW is a new web portal conceived for quick visualization of various satellite observations relevant for the stratospheric aerosols with a specific focus on extreme events, such as wildfires/pyroCb and volcanic eruptions reaching the stratosphere. GSAW provides visualization of Near-Real Time (NRT) data (delivered with a latency of 1-3 hours) as well as historical data dating back to 1979 for...
The limb-imaging Fourier transform infrared spectrometer GLORIA (Gimballed Limb Observer for Radiance Imaging of the Atmosphere) enables high-resolution remote sensing of trace gases in the upper troposphere and lower stratosphere (UTLS). During the PHILEAS (Probing High Latitude Export of Air from the Asian Summer Monsoon) campaign in August and September 2023, GLORIA was deployed aboard the...
The HAWC Mission is a Canadian contribution to the NASA AOS Mission designed to answer a combination of question posed within the recent decadal survey. Two main survey topics, Aerosols and Clouds, Convection and Precipitation, were originally merged into an American concept known as A-CCP. In the early days of A-CCP, Canada expressed interest in participating with a suite of national led...
The Microwave Limb Sounder (MLS) on the Aura satellite has been providing essential observations of ozone for the upper troposphere and lower stratosphere (UTLS). The relevance of the UTLS region for key weather and climate patterns, and coupling between the troposphere and stratosphere, highlights the capacity of MLS O3 to enhance weather forecasting.
This study investigates the impact...
Satellite instruments operating in limb-viewing geometry provide independent measurements of different parts of the atmosphere (e.g., stratospheric details without tropospheric interferences). Unfortunately, missions like MIPAS, ACE-FTS, or Aura/MLS have already ended or are expected to end several years before respective next-generation missions will be operative (e.g. the current ESA Earth...
Noctilucent clouds (NLCs) are optically thin ice clouds occurring near the polar mesopause in the summer hemisphere. Our understanding of the particle size of NLCs is to a large extent based on optical measurements in different observation geometries and optical NLC particle size retrievals are always based on a priori assumptions on the shape of the particle size distribution. The actual...
Molecular scattering (Rayleigh scattering) has been extensively used from the ground with lidars and from space to observe the limb, thereby deriving vertical temperature profiles between 30 and 80 km. In this study, we investigate how temperature can be measured using the new Ozone Mapping and Profiler Suite (OMPS) sensor, aboard the Suomi NPP and NOAA-21 satellites. The OMPS consists of...
The METEOR (MEsospheric TEmperature and Ozone climate data Record) project aims to develop a high-quality, long-term climate data record of mesospheric ozone and temperature by merging observations from multiple satellite instruments. A primary objective is to assess mesospheric temperature and ozone trends, with a particular focus on the impact of solar particle precipitation on ozone levels...
Many celestial bodies in the Solar System have been studied extensively using limb and occultation techniques, which have proven to be powerful tools for retrieving detailed information about the composition and dynamics of planetary atmospheres. These methods date back to the early 1970s, when NASA first deployed missions around Mars to investigate the planet’s atmospheric...
Although cyclones and anticyclones, referred to as synoptic events, strongly influence weather predictability, they are not well characterized or predicted in the Arctic region because of the sparse coverage of relevant meteorological measurements. As synoptic events at high latitudes influence the atmospheric dynamics in the region of the lower stratosphere and upper troposphere (UTLS) and...
OSIRIS is a Canadian spectrometer that was launched on the Swedish Odin satellite in 2001 for a two-year mission to explore the composition and coupling of the stratosphere and mesosphere. OSIRIS was designed to measure the spectra of scattered sunlight from the ultra-violet to the near-infrared to derive vertical profiles of trace gases and aerosols, a largely untested technique at the time....
This presentation is dedicated to evaluation of global and regional trends in ozone profiles using the updated merged datasets developed in the framework of ESA Climate Change Initiative for ozone project.
For trend analyses, two long-term merged datasets of ozone profiles have been created. One is the SAGE-CCI-OMPS+ climate data record of monthly zonal mean ozone profiles. This dataset...
Limb sounding has a number of advantages over nadir sounding for measuring trace gases in the atmosphere. Limb sounders measure with improved vertical resolution and can extend to higher altitudes. They measure spectra over longer pathlengths than their nadir counterparts, with an increased sensitivity to minor species. In the infrared, this increased sensitivity along with the typically...
The Stratospheric Aerosol and Gas Experiment (SAGE) III on the International Space Station (ISS) has now completed 8 years of successful operation. Performing solar and lunar occultation measurements that provide vertical profiles of aerosol extinction and key trace gases such as ozone and water vapor, the SAGE III/ISS data record has proven invaluable for assessing the impact of volcanic...
Owing to the stringent requirement on spectral resolution and line of sight pointing, hyperspectral thermal infrared (TIR) limb sounders of atmospheric composition tend to be large missions. SOLSTICE (Solar Occultation Limb Sounding Transformative Instrument for Climate Exploration) is a mission development programme supported by the UK Space Agency and the UK Centre for Earth Observation...
In tandem with the SOLSTICE instrument development (see related abstract ‘instrument development and qualification’) a mission simulator has been developed to evaluate the performance of the SOLSTICE system. The simulator includes production of synthetic Level 0 data raw from the instruments, the processing of calibrated atmospheric transmission as Level 1 data, and the ‘retrieval’ processor...
An important component of the reactive nitrogen (NO$_X$) budget of the stratosphere is nitrogen dioxide (NO$_2$), which participates in key reactions influencing the life cycle of stratospheric ozone. For example, it can limit the availability of reactive chlorine by forming chlorine nitrate (ClONO$_2$), but is also directly involved in catalytic cycles destroying ozone. A major source of...
On April 18, 2024, the Ruang volcano in North Sulawesi, Indonesia, erupted, sending volcanic materials up to 20 km altitude and drifting west of the Island. On April 29, Ruang erupted again, this time reaching an altitude of 21 km and following a similar trajectory to the earlier eruption. OMPS-NM UV measurements indicated that the volcanic clouds were primarily composed of sulfur dioxide...
Extreme events such as explosive volcanic eruptions and major wildfire outbreaks can produce persistent perturbations of stratospheric aerosol and gaseous composition. Volcanic eruptions, injecting ash and sulphuric aerosol precursors into the stratosphere, have historically been recognized as the primary source of large-scale perturbations of stratospheric aerosol load. An emerging source of...
On January 15, the Hunga volcano in the south west Pacific erupted injecting material into the stratosphere to altitudes up to or higher than 30 km. Estimates are that it injected 0.4 Tg of sulfur dioxide into the stratosphere and 150 Tg of water vapour. The sulfur mass injected was much smaller than that from the 1991 Mt. Pinatubo eruption, but the water injection was unprecedented over the...
The High-altitude Aerosols Water Vapour and Clouds (HAWC) satellite mission is Canada’s contribution to NASA’s upcoming Atmosphere Observing System (AOS). HAWC will provide observations that will focus on aerosols, clouds, and water vapor in the Upper Troposphere and Lower Stratosphere (UTLS), with coverage extending into the middle stratosphere and lower altitudes at the poles. The mission...
The Aerosol Limb Imager (ALI) instrument is currently being developed as part of the HAWC mission, which will include three Canadian instrument contributions to the NASA Atmosphere Observing System (AOS) mission. ALI will measure limb scattered radiances in the VIS-NIR spectral region at high vertical resolution and will include polarization information to better determine aerosol particle...
Physics and chemistry fundamentally govern stratospheric aerosol processing and dispersion following an injection event. While a self-evident statement, the exact course of those processes which govern residence time and final yields of chemical products like sulfuric acid can have significant uncertainty in the time period shortly following these events. Forecast models have a degree of power...
Observations of aerosol distributions in the Earth’s stratosphere represent a key input for Earth system models that need to characterize atmospheric heating. These aerosol measurements need good vertical resolution to capture variations in horizontal transport, dense spatial sampling to capture local structure, and regular temporal sampling to follow the evolution of aerosol injections at a...
The Changing-Atmosphere Infra-Red Tomography Explorer (CAIRT) is one of the two remaining candidate missions competing for implementation as ESA’s Earth Explorer 11. CAIRT aims to reveal, resolve, and unravel the complex coupling between composition, circulation, and climate in our middle atmosphere, by improving our knowledge of the chemical-dynamic-radiative interactions that govern our...
Stratospheric aerosols play an important role in atmospheric processes through their cooling effect on the surface and their role in cloud formation. Though aerosols have been widely studied for decades, there still exists a large gap between measurements and models. More refined measurements of aerosol size, shape, concentration and composition are required to close this gap to improve...
For over twenty years the SASKTRAN radiative transfer model has been used in the inversion of limb radiance observations from the OSIRIS instrument. SASKTRAN has since seen numerous upgrades that make it ideal for use in a variety of measurement scenarios across the UV, visible, and infrared spectral regimes. The next generation of the model, SASKTRAN2, is now available and has been completely...
The Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) is a cooled limb-imaging Fourier-Transform spectrometer (iFTS) providing mid-infrared spectra with high spectral resolution. A newly developed, compact and uncooled version of GLORIA (called GLORIA-Lite) is significantly smaller and lighter thanks to state-of-the-art infrared sensors, tailored electronics and...
Stratospheric cooling and contraction are projected to occur in response to increasing anthropogenic greenhouse gas emissions. However, temperature changes in the upper stratosphere, particularly above ~45 km, are difficult to quantify and model due to a deficit of observational data in this region. The recently developed v7.3 upper stratospheric (35--60 km) temperature data product from the...
One of the goals for the SPARC OCTAV-UTLS (Observed Composition Trends And Variability in the Upper Troposphere and Lower Stratosphere) activity is to quantify long-term changes in the UTLS ozone variability and identify the driving processes. The determination of atmospheric composition trends in the UTLS remains highly uncertain due to large atmospheric variability driven by chemistry,...
Stratospheric inorganic chlorine comprises product gases, e.g., HCl, produced by the decomposition of ozone-depleting substances (ODSs) such as chlorofluorocarbons (CFCs). Following action initiated under the 1987 Montreal Protocol, the tropospheric abundances of many long-lived ODSs have been declining as expected, leading to a corresponding decrease in total stratospheric inorganic chlorine...
The January 2022 eruption of the Hunga Tonga-Hunga Haʻapai (HTHH) volcano injected unprecedented volumes of aerosols and water vapor into the stratosphere. The evolution of the plume dynamics and chemical processing of the injected constituents is a unique event and opportunity of which even with global monitoring instruments instantaneous observations of that evolution are still sparse. One...
The Ozone Profiler and Mapping Suite (OMPS) Limb Profiler (LP) satellite instruments perform limb measurements of scattered solar radiation in the ultraviolet and visible wavelengths, which allow for the retrieval of high vertical resolution ozone profiles from the 12.5km to 57.5km with full global coverage. The first LP was launched on board the Suomi-NPP satellite in 2011 and started...
The budget of stratospheric water vapour is primarily controlled by the tropical upwelling of tropospheric air masses past the cold point tropopause and into the lower stratosphere. The strength of the tropical upwelling influences the thermal characteristics of the transition region between the troposphere and stratosphere (tropical tropopause layer), constraining water vapour transport to...
