scholarly journals Retrieval of daytime mesospheric ozone using OSIRIS observations of O<sub>2</sub> (<i>a</i><sup>1</sup>Δ<sub>g</sub>) emission

2020 ◽  
Vol 13 (11) ◽  
pp. 6215-6236
Author(s):  
Anqi Li ◽  
Chris Z. Roth ◽  
Kristell Pérot ◽  
Ole Martin Christensen ◽  
Adam Bourassa ◽  
...  
Keyword(s):  
Random Error ◽  
Middle Atmosphere ◽  
Lower Thermosphere ◽  
High Sensitivity ◽  
Retrieval Technique ◽  
Volume Emission ◽  
Mesospheric Ozone ◽  
Hartley Band ◽  
Along Track

Abstract. Improving knowledge of the ozone global distributions in the mesosphere–lower thermosphere (MLT) is a crucial step in understanding the behaviour of the middle atmosphere. However, the concentration of ozone under sunlit conditions in the MLT is often so low that its measurement requires instruments with very high sensitivity. Fortunately, the bright oxygen airglow can serve as a proxy to retrieve the daytime ozone density indirectly, due to the strong connection to ozone photolysis in the Hartley band. The OSIRIS IR imager (hereafter, IRI), one of the instruments on the Odin satellite, routinely measures the oxygen infrared atmospheric band (IRA band) at 1.27 µm. In this paper, we will primarily focus on the detailed description of the steps done for retrieving the calibrated IRA band limb radiance (with <10 % random error), the volume emission rate of O2 (a1Δg) (with <25 % random error) and finally the ozone number density (with <20 % random error). This retrieval technique is applied to a 1-year sample from the IRI dataset. The resulting product is a new ozone dataset with very tight along-track sampling distance (<20 km). The feasibility of the retrieval technique is demonstrated by a comparison of coincident ozone measurements from other instruments aboard the same spacecraft, as well as zonal mean and monthly average comparisons between Odin-OSIRIS (both spectrograph and IRI), Odin-SMR and Envisat-MIPAS. We find that IRI appears to have a positive bias of up to 25 % below 75 km, and up to 50 % in some regions above. We attribute these differences to uncertainty in the IRI calibration as well as uncertainties in the photochemical constants. However, the IRI ozone dataset is consistent with the compared dataset in terms of the overall atmospheric distribution of ozone between 50 and 100 km. If the origin of the bias can be identified before processing the entire dataset, this will be corrected and noted in the dataset description. The retrieval technique described in this paper can be further applied to all the measurements made throughout the 19 year mission, leading to a new, long-term high-resolution ozone dataset in the middle atmosphere.

scholarly journals Retrieval of daytime mesospheric ozone using OSIRIS observation of O<sub>2</sub>(a<sup>1</sup>∆<sub>g</sub>) emission

2020 ◽  
Author(s):  
Anqi Li ◽  
Chris Roth ◽  
Kristell Pérot ◽  
Ole Martin Christensen ◽  
Adam M. Bourassa ◽  
...  
Keyword(s):  
Middle Atmosphere ◽  
Lower Thermosphere ◽  
High Sensitivity ◽  
Retrieval Technique ◽  
Volume Emission ◽  
Hartley Band ◽  
One Year ◽  
Along Track ◽  
Very High

Abstract. Improving knowledge of the ozone global distributions in the mesosphere-lower thermosphere (MLT) is a crucial step in understanding the behaviour of the middle atmosphere. However, the ozone concentration under sunlit conditions in the MLT is often so low that its measurement requires instruments with very high sensitivity. Fortunately, the bright oxygen airglow can serve as a proxy to retrieve the daytime ozone density indirectly, due to the strong connection to ozone photolysis in the Hartley band. The OSIRIS IR imager (hereafter IRI), one of the instruments on the Odin satellite, routinely measures the oxygen infrared atmospheric band (IRA band) at 1.27 μm. In this paper, we will describe the detailed steps of retrieving the calibrated IRA band limb radiance, the volume emission rate of O2(a1∆g) and, finally, the ozone number density. This retrieval technique is applied to a one-year-sample IRI dataset. The resulting product is a completely new ozone dataset with very high along-track resolution. The performance of the retrieval technique is demonstrated by a comparison of the coincident ozone measurements from the same spacecraft, as well as zonal mean and monthly average comparisons between OS, SMR, MIPAS and ACE-FTS. The consistency of this IRI ozone dataset implies that such a retrieval technique can be further applied to all the measurements made throughout the 19 years-long mission, leading to a long-term, high resolution dataset in the middle atmosphere.

scholarly journals Global change induced trends in ion composition of the troposphere to the lower thermosphere

2008 ◽  
Vol 26 (5) ◽  
pp. 1181-1187 ◽  
Author(s):  
G. Beig
Keyword(s):  
Middle Atmosphere ◽  
Anthropogenic Activities ◽  
Lower Thermosphere ◽  
Cluster Ions ◽  
Atmospheric Density ◽  
Mesosphere And Lower Thermosphere ◽  
Induced Changes ◽  
Positive Ion ◽  
Mlt Region

Abstract. In this paper a brief overview of the changes in atmospheric ion compositions driven by the human-induced changes in related neutral species, and temperature from the troposphere to lower thermosphere has been made. It is found that ionic compositions undergo significant variations. The variations calculated for the double-CO2 scenario are both long-term and permanent in nature. Major neutrals which take part in the lower and middle atmospheric ion chemical schemes and undergo significant changes due to anthropogenic activities are: O, O2, H2O, NO, acetonitrile, pyridinated compounds, acetone and aerosol. The concentration of positive ion/electron density does not change appreciably in the middle atmosphere but indicates a marginal decrease above about 75 km until about 85 km, above which the magnitude of negative trend decreases and becomes negligible at 93 km. Acetonitrile cluster ions in the upper stratosphere are likely to increase, whereas NO+ and NO+(H2O) in the mesosphere and lower thermosphere (MLT) region are expected to decrease for the double CO2 scenario. It is also found that the atmospheric density of pyridinated cluster ions is fast rising in the troposphere.

Temperatures in the upper mesosphere and lower thermosphere from OSIRIS observations of O2 A-band emission spectra

2010 ◽  
Vol 88 (12) ◽  
pp. 919-925 ◽  
Author(s):  
P. E. Sheese ◽  
E. J. Llewellyn ◽  
R. L. Gattinger ◽  
A. E. Bourassa ◽  
D. A. Degenstein ◽  
...  
Keyword(s):  
Infrared Imaging ◽  
Imaging System ◽  
Lower Thermosphere ◽  
Emission Spectra ◽  
Temperature Dependent ◽  
Band Emission ◽  
Retrieval Technique ◽  
Volume Emission ◽  
Band Spectra ◽  
Temperature Retrieval

Temperatures in the mesosphere – lower thermosphere region (MLT) have been derived from the Optical Spectrograph and InfraRed Imaging System (OSIRIS) observations of O2 A-band (b1Σ g+ –X3Σ g– )O–O emission spectra. The observed OSIRIS spectra are inverted pixel by pixel, producing inverted volume emission rate spectra at altitudes between 90 and 110 km, which are compared to modelled temperature dependent O2 A-band spectra. The estimated accuracy of the retrieved temperatures is approximately ±2 K near 90 km and up to ±6 K at higher altitudes. The developed temperature retrieval technique is presented, and some initial retrieval results are briefly discussed.

scholarly journals The OH (3-1) nightglow volume emission rate retrieved from OSIRIS measurements: 2001 to 2015

2021 ◽  
Vol 13 (11) ◽  
pp. 5115-5126
Author(s):  
Anqi Li ◽  
Chris Z. Roth ◽  
Adam E. Bourassa ◽  
Douglas A. Degenstein ◽  
Kristell Pérot ◽  
...  
Keyword(s):  
Emission Rate ◽  
Lower Thermosphere ◽  
Polar Regions ◽  
Night Time ◽  
Data Set ◽  
Infrared Imager ◽  
Data Products ◽  
Long Time ◽  
Volume Emission

Abstract. The OH airglow has been used to investigate the chemistry and dynamics of the mesosphere and the lower thermosphere (MLT) for a long time. The infrared imager (IRI) aboard the Odin satellite has been recording the night-time 1.53 µm OH (3-1) emission for more than 15 years (2001–2015), and we have recently processed the complete data set. The newly derived data products contain the volume emission rate profiles and the Gaussian-approximated layer height, thickness, peak intensity and zenith intensity, and their corresponding error estimates. In this study, we describe the retrieval steps for these data products. We also provide data screening recommendations. The monthly zonal averages depict the well-known annual oscillation and semi-annual oscillation signatures, which demonstrate the fidelity of the data set (https://doi.org/10.5281/zenodo.4746506, Li et al., 2021). The uniqueness of this Odin IRI OH long-term data set makes it valuable for studying various topics, for instance, the sudden stratospheric warming events in the polar regions and solar cycle influences on the MLT.

Long-term changes in mesospheric wind and wave estimates based on radar observations in both hemispheres

2021 ◽  
Author(s):  
Ales Kuchar ◽  
Gunter Stober ◽  
Christoph Jacobi ◽  
Dimitry Pokhotelov ◽  
Huxin Liu ◽  
...  
Keyword(s):  
Gravity Wave ◽  
Middle Atmosphere ◽  
Lower Thermosphere ◽  
Multiple Linear Regression Model ◽  
Original Data ◽  
Negative Trend ◽  
Summer Circulation ◽  
Long Term Changes ◽  
Mlt Dynamics

&lt;p class=&quot;western&quot;&gt;Several studies (Banerjee et al. (2020) and before that Sun et al. (2014)) found a trend reversal between winter and summer circulation in the southern hemisphere around 2000 in the middle atmosphere. One may argue that the negative trend after 2000 is due to the CO&lt;sub&gt;2&lt;/sub&gt;-induced change in stratospheric dynamics. However, Ramesh et al. (2020), using the newest WACCM6 simulation and a multiple linear regression model, confirmed that the negative trend in the stratosphere after 2000 can be attributed to ozone recovery. Here we investigate how stratospheric trends relate to trends in the mesosphere and lower thermosphere (MLT) dynamics. Using the adaptive spectral filtering (ASF) method (Stober et al., 2021), we study long-term changes in mesospheric wind and planetary and gravity wave estimates&lt;span lang=&quot;en-GB&quot;&gt; of meteor radar stations in the northern (NH: Collm, Kiruna, Sodankyla, CM&lt;/span&gt;&lt;span lang=&quot;en-GB&quot;&gt;OR&lt;/span&gt;&lt;span lang=&quot;en-GB&quot;&gt;) and southern (SH: Rio Grande, Davis, Rothera) hemisphere, respectively, for the altitude range of 80&amp;#8211;100 km. &lt;/span&gt;Linear trends have been estimated (from monthly means calculated from the preprocessed original data using ASF) by the Theil&amp;#8211;Sen estimator (Theil, 1950; Sen, 1968). The robustness of our fitting method is assessed in terms of spurious trends due to, e.g., high autocorrelation of relatively short time series. The long-term changes are validated in two whole-atmosphere models, namely, GAIA and WACCMX-SD (both nudged in the stratosphere). While both models reveal issues reproducing basic climatology in the mesosphere, GAIA fairly reproduces the trends captured by the meteor radars. Finally, we conclude that the ozone recovery effects in the SH stratosphere influence the dynamics in MLT via gravity wave coupling.&lt;/p&gt;

scholarly journals Improved GOMOS/Envisat ozone retrievals in the upper troposphere and the lower stratosphere

2017 ◽  
Vol 10 (1) ◽  
pp. 231-246 ◽  
Author(s):  
Viktoria F. Sofieva ◽  
Iolanda Ialongo ◽  
Janne Hakkarainen ◽  
Erkki Kyrölä ◽  
Johanna Tamminen ◽  
...  
Keyword(s):  
Lower Stratosphere ◽  
Middle Atmosphere ◽  
Lower Thermosphere ◽  
High Sensitivity ◽  
Retrieval Algorithm ◽  
Inversion Algorithm ◽  
Upper Troposphere ◽  
Spectral Inversion ◽  
Vertical Range ◽  
Visible Wavelengths

Abstract. Global Ozone Monitoring by Occultation of Stars (GOMOS) on board Envisat has performed about 440 000 nighttime occultations during 2002–2012. Self-calibrating measurement principle, good vertical resolution, excellent pointing accuracy, and the wide vertical range from the troposphere up to the lower thermosphere make GOMOS profiles interesting for different analyses. The GOMOS ozone data are of high quality in the stratosphere and the mesosphere, but the current operational retrieval algorithm (IPF v6) is not optimized for retrievals in the upper troposphere–lower stratosphere (UTLS). In particular, validation of GOMOS profiles against ozonesonde data has revealed a substantial positive bias (up to 100 %) in the UTLS region. The retrievals in the UTLS are challenging because of low signal-to-noise ratio and the presence of clouds. In this work, we discuss the reasons for the systematic uncertainties in the UTLS with the IPF v6 algorithm or its modifications based on simultaneous retrievals of several constituents using the full visible wavelength range. The main reason is high sensitivity of the UTLS retrieval algorithms to an assumed aerosol extinction model. We have developed a new ozone profile inversion algorithm for GOMOS data (ALGOM2s version 1.0), which is optimized in the UTLS and uses IPF v6 advantages in the middle atmosphere. The ozone retrievals in the whole altitude range from the troposphere to the lower thermosphere are performed in two steps, as in the operational algorithm: spectral inversion followed by the vertical inversion. The spectral inversion is enhanced by using a DOAS-type method at visible wavelengths for the UTLS region. This method uses minimal assumptions about the atmospheric profiles. The vertical inversion is performed as in IPF v6 with the Tikhonov-type regularization according to the target resolution. The validation of new retrieved ozone profiles with ozonesondes shows a dramatic reduction of GOMOS ozone biases in the UTLS. The new GOMOS ozone profiles are also in a very good agreement with measurements by MIPAS, ACE-FTS, and OSIRIS satellite instruments in the UTLS. It is also shown that the known geophysical phenomena in the UTLS ozone are well reproduced with the new GOMOS data.

THE MICROWAVE MONITORING OF THE MIDDLE ATMOSPHERE OZONE ON KOLA PENINSULA DURING LAST THREE WINTERS

2021 ◽  
Vol 44 ◽  
pp. 168-171
Author(s):  
Y.Y. Kulikov ◽  
◽  
A.F. Andriyanov ◽  
V.G. Ryskin ◽  
V.M. Demkin ◽  
...  
Keyword(s):  
Middle Atmosphere ◽  
Microwave Radiometry ◽  
Vertical Profiles ◽  
Stratospheric Warming ◽  
Geophysical Institute ◽  
Sudden Stratospheric Warming ◽  
Polar Geophysical Institute ◽  
Mesospheric Ozone ◽  
The Vertical Distribution

This work presents long-term investigation of a nature of the middle atmosphere ozone variability using a method ground-based microwave radiometry. Measurements were carried out with the help of mobile microwave ozonemeter (observation frequency 110836.04 MHz) which was established in Polar Geophysical Institute at Apatity (67N, 33E). The parameters of the device allow to measure a spectrum of the emission ozone line for time about 15 min with a precision of ~ 2%. The error of estimating the vertical distribution of ozone on the measured spectra by above described device does not exceed 10-15%. On the measured spectra were appreciated of ozone vertical profiles in the layer of 22 – 60 km which were compared to satellite data MLS/Aura and with the data of ozonesondes at station Sodankyla (67N, 27E). The analysis of the microwave data on behavior of polar mesospheric ozone in past winters shows, that sudden stratospheric warming (SSW) can cause significant and long influence on its diurnal variation which should be determined by photochemical processes.

scholarly journals Large-Scale Waves in the Mesosphere and Lower Thermosphere Observed by SABER

2005 ◽  
Vol 62 (12) ◽  
pp. 4384-4399 ◽  
Author(s):  
Rolando R. Garcia ◽  
Ruth Lieberman ◽  
James M. Russell ◽  
Martin G. Mlynczak
Keyword(s):  
Large Scale ◽  
Middle Atmosphere ◽  
Lower Thermosphere ◽  
Normal Modes ◽  
Zonal Winds ◽  
Broadband Emission ◽  
Summer Hemisphere ◽  
Mean Structure ◽  
Mesosphere And Lower Thermosphere ◽  
The Tropics

Abstract Observations made by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on board NASA’s Thermosphere–Ionosphere–Mesosphere Energetics and Dynamics (TIMED) satellite have been processed using Salby’s fast Fourier synoptic mapping (FFSM) algorithm. The mapped data provide a first synoptic look at the mean structure and traveling waves of the mesosphere and lower thermosphere (MLT) since the launch of the TIMED satellite in December 2001. The results show the presence of various wave modes in the MLT, which reach largest amplitude above the mesopause and include Kelvin and Rossby–gravity waves, eastward-propagating diurnal oscillations (“non-sun-synchronous tides”), and a set of quasi-normal modes associated with the so-called 2-day wave. The latter exhibits marked seasonal variability, attaining large amplitudes during the solstices and all but disappearing at the equinoxes. SABER data also show a strong quasi-stationary Rossby wave signal throughout the middle atmosphere of the winter hemisphere; the signal extends into the Tropics and even into the summer hemisphere in the MLT, suggesting ducting by westerly background zonal winds. At certain times of the year, the 5-day Rossby normal mode and the 4-day wave associated with instability of the polar night jet are also prominent in SABER data.

Near-infrared persistent luminescence hollow mesoporous nanospheres for drug delivery and in vivo renewable imaging

2016 ◽  
Vol 4 (48) ◽  
pp. 7845-7851 ◽  
Author(s):  
Junpeng Shi ◽  
Meng Sun ◽  
Xia Sun ◽  
Hongwu Zhang
Keyword(s):  
Drug Delivery ◽  
Near Infrared ◽  
High Sensitivity ◽  
Drug Carriers ◽  
Template Method ◽  
Persistent Luminescence ◽  
Deep Tissue ◽  
Large Capacity

Near-infrared persistent luminescence hollow mesoporous nanospheres have been synthesized via a template method. These nanospheres can be used as large capacity drug carriers and realize super long-term and high sensitivity tracking of drug delivery in deep tissue.

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