In this paper, the photochemical equilibrium of the odd oxygen and hydrogen families at altitudes of 50-80 km has been investigated via a three-dimensional chemistry-transport model. It is shown that there are wide enough ranges of latitudes, altitudes, and local times when the true concentration value of these families is in the ten percent vicinity of their instantaneous equilibrium values. In this case, the concentrations of these families can be considered to be in equilibrium and appropriate algebraic equations can be used to retrieve poorly measured minor mesospheric constituents, to validate measurement data, or to refine photochemical reaction constants.
The components of the mesosphere lower thermosphere region satisfy the algebraic relations resulting from the photochemistry. Applications of this relations to already self-sufficient measurements leads to a certain redundancy in form of functional relationship between the measured quantities. Airglow models are the key element in mesospheric measurements. The work considers the application of these relationships to satellite data series in order to improve airglow model (of excited hydroxyl). We investigate the problem in its general formulation. Using probabilistic approach we derive the method to determine airglow model coefficients analyzing long term observations. An upper estimate is made for the number of independently determined coefficients of the model.
KEYWORDS: Data modeling, Thermosphere, Mesosphere, Temperature distribution, Ozone, Chemical analysis, Atmospheric physics, Satellites, Air temperature, Ultraviolet radiation
The model of excited OH with constants corresponding to the published data was applied to retrieve nighttime distributions of О, Н, ОН, НО2, and the chemical heating rate at the altitudes of 80–100 km from the data of the SABER/TIMED measurements in 2021. The analysis revealed that the new parameters of the retrieval procedure result in significant changes in O, H, and the chemical heating rate, but not for the OH and HO2 distributions.
Measurements of atmospheric radiation over Nizhny Novgorod at the frequencies of the 5 mm band of molecular oxygen were carried out simultaneously with two devices: Spectroradiometer IAP RAS and RPG-HATPRO profiler. Comparison of the results at matching frequencies showed that the difference in the values of the measured brightness temperatures for a clear atmosphere in the zenith direction can reach 3 K, which significantly exceeds their variations during observation time. Such discrepancies should be taken into account when using these data to retrieval the troposphere temperature profile.
The conditions for the feasibility of the daytime photochemical equilibrium approximation of the odd oxygen (Ox) and hydrogen (HOx) families at altitudes of 50-80 km has been investigated with the use of analytical analysis and a onedimensional model. We proposed the criteria of their equilibrium. It’s shown that when the criterion is limited to 0.1, the difference between the true values of the concentrations of Ox and HOx and their local equilibrium values is approximately 10%. In this case, one can consider their concentrations to be in an equilibrium and use corresponding algebraic equations in different practical applications.
The revised model of excited OH with constants corresponding to the published data was applied to retrieve daytime O and H distributions at 77 km–100 km from the data of the SABER/TIMED satellite measurements in 2002–2021. It was found that changes of parameters in the retrieved procedure lead to (1) a noticeable (up to 30%) increase of the O concentration below 85-86 km, (2) a significant (up to 170%) increase of the H concentration below 90 km and a moderate (up to 40%) decrease near 100 km. The influence of revised O and H data on the retrieval of OH and HO2 is also analyzed.
We analyze the seasonal dependency of retrieval error in remote sensing problem while the quantity to be retrieved has seasonal evolution. In particular we estimate the seasonality in tropospheric measurements by HATPRO microwave profiler. For that we employ several methods: estimation using linearized retrieval procedure (employing error analysis), retrieval simulations, and direct comparison of real measurements with radiosonde data from the nearest aerological station.
The atmospheric boundary layer height is a key parameter characterizing this layer. The accurate evaluation of this parameter is critically important for almost all tropospheric research. Recently, remote sensing technique with the use of microwave passive radiometers is widely used for these purposes. IAP RAS performs continuous measurements of troposphere parameters (temperature and water vapor profiles) by the microwave profiler RPG HATPRO-G3. In this work, the dataset obtained during 2013 – 2018 is applied for determining the boundary layer height over Nizhny Novgorod. We compare the results with the estimation of boundary layer height from radiosonde data.
The feasibility of the daytime photochemical equilibrium of families of the odd oxygen and hydrogen at the altitudes of 50-80 km has been investigated via a one-dimensional model. It’s shown that if the permissible alterations between true values of the concentrations of these families and their instant-equilibrium values are limited to 10%, there are quite wide ranges of heights and local times in which we can consider the concentrations of these families to be in an equilibrium and use suitable algebraic equations to retrieve poorly measured minor constituents of mesosphere, validate measured data or refine constants of photochemical reactions.
On the example of the SABER/TIMED satellite data measured in 2003, we analyze the quality of daytime O and H retrieval at the altitudes of the mesosphere - lower thermosphere with the use of the condition of ozone photochemical equilibrium, which takes into account only the main chemical sink of this component due to photodissociation. It is shown that neglecting the reaction H+O3→O2+OH in this condition weakly manifests itself in the H distributions, but leads to a significant (up to 50-70%) systematic underestimation of the monthly mean and annually mean O distributions at the altitudes of 75-90 km.
We conduct an analysis of simultaneous measurements of microwave profiler RPGH-HATPRO and radiosonde which were obtained during 2013-2018 observation period. Using microwave data, we quantify the cloudiness of the conditions. We consider two datasets depending on cloudiness: moderate clouds and clear sky. The latter subset of the former. We investigate means and standard deviations of the difference between the temperature profiles retrieved from microwave data and radiosonde profiles. The seasonal means are at least two times the amplitude of whole dataset means. We discuss the reasons for observed behavior.
We use the data-driven stochastic model for reconstruction of variability of the North Atlantic Oscillation (NAO) and its response to anthropogenic forcing. We apply the data-driven model to both the data produced by INM RAS Climate Model and NCEP / NCAR reanalysis data. The data-driven model reproduces well the characteristic statistical properties of the NAO index, such as skewness. We predict the NAO variability in the 21st century under various scenarios of anthropogenic CO2 emissions using data-driven model. The study was supported by the Russian Science Foundation (grant No. 9-42-04121).
In this work we investigate connection between mid-latitude atmosphere and principal modes of global sea surface temperature (SST). For this purpose, we apply the linear dynamical mode decomposition to the monthly SST anomalies: the obtained modes describe the Pacific Decadal Oscillation and the El-Niño Southern Oscillation (ENSO). We analyze the regression of atmospheric characteristics on the time-shifted modes and detect bidirectional connections between ENSO and the mid-latitude atmosphere up to one-year delay. The work was carried out within the framework of the Program for the Development of the Regional Scientifc and Educational Mathematical Center "Mathematics of Future Technologies", project #075-02-2020-1483/1.
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