scholarly journals FAST SUBAURORAL DRIFTS OF IONOSPHERE PLASMA ACCORDING TO DATA FROM YAKUT MERIDIONAL CHAIN OF STATIONS

2019 ◽  
Vol 5 (4) ◽  
pp. 60-65
Author(s):  
Alexander Stepanov ◽  
Sargylana Kobyakova ◽  
Viktor Khalipov
Keyword(s):  
Electric Fields ◽  
Satellite Data ◽  
Satellite Measurements ◽  
Appearance Time ◽  
Ion Drift ◽  
Ion Drifts ◽  
Ionosphere Plasma ◽  
Term Data ◽  
Good Agreement

Using long-term data from Yakut meridional chain of Yakutsk — Zhigansk — Batagay — Tixie ionospheric stations, we study ionospheric signatures of fast subauroral ion drift. Sharp drops or “falls” of critical frequencies (FCF) of the ionospheric F layer are shown to be one of the main signatures of the development of fast subauroral ion drifts near or at the zenith of the observation station. Comparison between long-term ground-based and satellite measurements indicates that there is good agreement between seasonal variation in the probability of occurrence of FCF derived from ground-based data and subauroral ion drifts derived from DMSP satellite data. Such a coincidence implies that both satellite and ground-based measurement methods register the same phenomenon in the boundary layers of the plasmasphere, namely, the appearance and development of electric fields of magnetospheric origin. The local time for recording of falls of the critical frequency derived from the ground-based data is shown to closely coincide with the appearance time of subauroral polarization streams of plasma according to satellite data. We can therefore conclude that most of the observed FCFs derived from ground-based data refer to intense storms.

scholarly journals FAST SUBAURORAL DRIFTS OF IONOSPHERE PLASMA ACCORDING TO DATA FROM YAKUT MERIDIONAL CHAIN OF STATIONS

2019 ◽  
Vol 5 (4) ◽  
pp. 73-79
Author(s):  
Aleksandr Stepanov ◽  
Sargylana Kobyakova ◽  
Viktor Khalipov
Keyword(s):  
Electric Fields ◽  
Satellite Data ◽  
Satellite Measurements ◽  
Appearance Time ◽  
Ion Drift ◽  
Ion Drifts ◽  
Ionosphere Plasma ◽  
Term Data ◽  
Good Agreement

Using long-term data from Yakut meridional chain of Yakutsk — Zhigansk — Batagay — Tixie ionospheric stations, we study ionospheric signatures of fast subauroral ion drift. Sharp drops or “falls” of critical frequencies (FCF) of the ionospheric F layer are shown to be one of the main signatures of the development of fast subauroral ion drifts near or at the zenith of the observation station. Comparison between long-term ground-based and satellite measurements indicates that there is good agreement between seasonal variation in the probability of occurrence of FCF derived from ground-based data and subauroral ion drifts derived from DMSP satellite data. Such a coincidence implies that both satellite and ground-based measurement methods register the same phenomenon in the boundary layers of the plasmasphere, namely, the appearance and development of electric fields of magnetospheric origin. The local time for recording of falls of the critical frequency derived from the ground-based data is shown to closely coincide with the appearance time of subauroral polarization streams of plasma according to satellite data. We can therefore conclude that most of the observed FCFs derived from ground-based data refer to intense storms.

scholarly journals Long-term trends observed in the middle atmosphere temperatures using ground based LIDARs and satellite borne measurements

2014 ◽  
Vol 32 (3) ◽  
pp. 301-317 ◽  
Author(s):  
P. Kishore ◽  
M. Venkat Ratnam ◽  
I. Velicogna ◽  
V. Sivakumar ◽  
H. Bencherif ◽  
...  
Keyword(s):  
Middle Atmosphere ◽  
Southern Oscillation ◽  
Warming Trend ◽  
Satellite Measurements ◽  
Long Term Trends ◽  
Maximum Warming ◽  
Cooling Trend ◽  
Term Data ◽  
Good Agreement

Abstract. Long-term data available from Lidar systems located at three different locations namely São José dos Campos, Brazil (23.2° S, 45.8° W), Gadanki (13.5° N, 79.2° E) and Reunion (20.8° S, 55.5° E) have been used to investigate the long-term variations like Annual, Semi-annual, Quasi-biennial, El Nino Southern Oscillation and solar cycle. These oscillations are also extracted from simultaneous satellite borne measurements of HALogen Occultation Experiment (HALOE) instrument onboard UARS and SABER onboard TIMED over these stations making largest time series covering the entire middle atmosphere. A good agreement is found between the LIDAR and satellite-derived amplitudes and phases between 30 and 65 km altitude, which suggests that satellite measurements can be used to investigate the long-term trends globally. Latter measurements are extended to 80 km in order to further investigate these oscillations. Large difference in the amplitudes between the eastern pacific and western pacific is noticed in these oscillations. Changing from cooling trends in the stratosphere to warming trends in the mesosphere occurs more or less at altitude around 70 km altitude and this result agrees well with that observed by satellite measurements reported in the literature. The peak in the cooling trend does not occur at a fixed altitude in the stratosphere however maximum warming trend is observed around 75 km at all the stations. The observed long-term trends including various oscillations are compared with that reported with various techniques.

scholarly journals Variations of carbon monoxide in the atmosphere of Antarctica according to ground-based and satellite measurements

2019 ◽  
pp. 97-106 ◽  
Author(s):  
V. P. Ustinov ◽  
E. L. Baranova ◽  
K. N. Visheratin ◽  
M. I. Grachev ◽  
A. V. Kalsin
Keyword(s):  
Satellite Data ◽  
Total Content ◽  
Mixing Ratio ◽  
Satellite Measurements ◽  
Average Volume ◽  
Average Deviation ◽  
Average Value ◽  
Surface Measurements ◽  
Good Agreement ◽  
Measurement Period

The results of systematic (2003–2017) measurements of the total content and the volume mixing ratio of CO at Novolazarevskaya station with a spectrometer with a resolution of 0.2 cm– 1 are presented. The inverse problem of determining the total CO content, as well as interfering gases (H2O and N2O), was solved using the SFIT4 software package. Data analysis showed that over the measurement period the average total CO content at Novolazarevskaya amounted to (8 ± 2) 1017 molec/cm2, and the average volume mixing ratio amounted to (37 ± 8) ppb. The obtained data are compared with variations in the total content of CO in Arrival-Heights station, with MOPITT satellite data, as well as with surface values of CO concentration at Syova station. The maximum values of CO are observed in September, the minimum — in January–February. For all the considered series, the trends are insignificant, while there are periods of increased CO content (2010). In recent years (2014–2017) there is a tendency towards an increase in the minimum values of CO. For  Novolazarevskaya and  Arrival-Heights satellite data are characterized by the excess of over ground data, amounting to 19% and 14%, respectively, while there is a seasonal dependence of the deviation with the minimum in December–January. Surface measurements of the total CO content are in fairly good agreement at Novolazarevskaya and Arrival-Heights, and since 2010 the average deviation is 2.4%. The average value of the concentration of CO on Syova 51 ppb is higher than the average volume mixing ratio at Novolazarevskaya. According to the spectral, wavelet and composite analyzes, in all the considered series there are oscillations in the range of 6–45 months with closely coinciding periods and phases.

scholarly journals Comparison of the optical depth of total ozone and atmospheric aerosols in Poprad-Gánovce, Slovakia

2017 ◽  
Author(s):  
Peter Hrabčák
Keyword(s):  
Ultraviolet Radiation ◽  
Optical Depth ◽  
Satellite Data ◽  
Atmospheric Aerosols ◽  
Total Ozone ◽  
Solar Spectrum ◽  
Atmospheric Ozone ◽  
Satellite Measurements ◽  
Two Factors

Abstract. Atmospheric ozone along with aerosols significantly affect the amount of ultraviolet solar radiation that reaches on the Earth's surface. Presented study is focused on the comparison of the optical depth of total ozone and atmospheric aerosols in the area of Poprad-Gánovce situated at the altitude of 706 meters above sea level, close to the highest peak of the Carpathian Mountains. Measurements of direct sun ultraviolet radiation are carried out here continuously since 1994 using the Brewer Ozone Spectrophotometer type MK IV. These measurements are used to calculate the total amount of atmospheric ozone and consequently its optical depth. Measurements can also be used to determine the optical depth of atmospheric aerosols using the Langley plot method. In this study, those two factors causing a significant reduction in the direct sun ultraviolet radiation to the Earth's surface are compared to each other. The study is showing results of measurements over 23 years, since 1994 to 2016. Values of optical depth are determined for wavelengths 306.3 nm, 310.1 nm, 313.5 nm, 316.8 nm and 320.1 nm. A statistically significant decrease in the total optical depth of the atmosphere was observed for all investigated wavelengths. Its main cause is the decrease of optical depth of aerosols. The study also presents comparison of the terrestrial and satellite data of total ozone and AOD. A very good match of satellite and terrestrial direct sun measurements of total ozone was found. The use of zenith sky measurements in combination with the direct sun measurements leads to the systematically higher values of total ozone. Comparison of the satellite and terrestrial AOD measurements in the UV range of the solar spectrum is mainly limited by the very low number of days for which AOD can be determined for satellite measurements. It has been found that AOD satellite data is higher than terrestrial in the long-term average.

scholarly journals Eastward sub-auroral ion drifts or ASAID

2008 ◽  
Vol 26 (7) ◽  
pp. 1955-1963 ◽  
Author(s):  
M. Voiculescu ◽  
M. Roth
Keyword(s):  
Satellite Data ◽  
Convective Transport ◽  
Data Sampling ◽  
Ion Temperature ◽  
Ion Density ◽  
Ion Drift ◽  
Ion Drifts ◽  
F Region ◽  
Entire Duration ◽  
Spatial Locations

Abstract. From satellite data sampling the top ionosphere in the Northern Hemisphere we have identified strong eastward ion drifts, with speeds larger than 1 km/s, widths of 1°–2°, occurring at similar temporal and spatial locations as rapid westward ion drifts known as sub-auroral ion drifts (SAID). We have called these events "abnormal sub-auroral ion drifts" (ASAID). Two events observed in the 20:00–22:00 MLT interval are discussed: the first occurring on 21 September 2003 and the other on 12 October 2003. Tomographic reconstructions of the electron density in the F-region, based on satellite data, provided by the Scandinavian tomography chain, were also available. We have observed that ASAID are accompanied by upward flows with a speed of the same order as that of the zonal ion drift. They coincide with deep, narrow troughs in the total ion density, both at the altitude of the F15 DMSP satellite (850 km) and in the F-region of the ionosphere, but do not seem to be a feature of the convective transport. During the entire duration of ASAID the electron temperature is very high while, contrary to SAID, the ion temperature has no clear variation. Both events described in this paper end up turning into classical SAID. Satellite data indicate that the generator of ASAID could be located inside the plasmasphere close to the plasmapause and we suggest a possible mechanism for their formation.

scholarly journals Mean age of stratospheric air derived from AirCore observations

2017 ◽  
Vol 17 (11) ◽  
pp. 6825-6838 ◽  
Author(s):  
Andreas Engel ◽  
Harald Bönisch ◽  
Markus Ullrich ◽  
Robert Sitals ◽  
Olivier Membrive ◽  
...  
Keyword(s):  
Low Cost ◽  
Positive Trend ◽  
Data Set ◽  
Model Calculations ◽  
Significant Positive Trend ◽  
Stratospheric Balloon ◽  
Term Data ◽  
Better Than ◽  
Good Agreement

Abstract. Mean age of stratospheric air can be derived from observations of sufficiently long-lived trace gases with approximately linear trends in the troposphere. Mean age can serve as a tracer to investigate stratospheric transport and long-term changes in the strength of the overturning Brewer–Dobson circulation of the stratosphere. For this purpose, a low-cost method is required in order to allow for regular observations up to altitudes of about 30 km. Despite the desired low costs, high precision and accuracy are required in order to determine mean age. We present balloon-borne AirCore observations from two midlatitude sites: Timmins in Ontario/Canada and Lindenberg in Germany. During the Timmins campaign, five AirCores sampled air in parallel with a large stratospheric balloon and were analysed for CO2, CH4 and partly CO. We show that there is good agreement between the different AirCores (better than 0.1 %), especially when vertical gradients are small. The measurements from Lindenberg were performed using small low-cost balloons and yielded very comparable results. We have used the observations to extend our long-term data set of mean age observations at Northern Hemisphere midlatitudes. The time series now covers more than 40 years and shows a small, statistically non-significant positive trend of 0.15 ± 0.18 years decade−1. This trend is slightly smaller than the previous estimate of 0.24 ± 0.22 years decade−1 which was based on observations up to the year 2006. These observations are still in contrast to strong negative trends of mean age as derived from some model calculations.

A Long-Term Data Set of Vertical Ion Drift Velocity at High Latitudes Constructed From DMSP Measurements

2018 ◽  
Vol 123 (7) ◽  
pp. 6090-6102
Author(s):  
Mohan Liu ◽  
Xiao-Xin Zhang ◽  
Fei He ◽  
Wenbin Wang
Keyword(s):  
Drift Velocity ◽  
High Latitudes ◽  
Data Set ◽  
Ion Drift ◽  
Term Data

scholarly journals Comparing temperature of subauroral mesopause over Yakutia with SABER radiometer data for 2002–2014

2017 ◽  
Vol 3 (2) ◽  
pp. 58-63
Author(s):  
Анастасия Аммосова ◽  
Anastasiya Ammosova ◽  
Галина Гаврильева ◽  
Galina Gavrilyeva ◽  
Петр Аммосов ◽  
...  
Keyword(s):  
Spectral Measurements ◽  
Satellite Measurements ◽  
Mesopause Region ◽  
Temperature Variations ◽  
Broadband Emission ◽  
Long Term Trends ◽  
The Difference ◽  
Temperature Time ◽  
Good Agreement

We present the temperature database for the mesopause region, which was collected from spectral measurements of bands O2(0-1) and OH(6-2) with the infrared spectrograph SP-50 at the Maimaga station (63° N; 129.5° E) in 2002–2014. The temperature time series covers 11-year solar cycle. It is compared with the temperature obtained with the Sounding of the At-mosphere using Broadband Emission Radiometry in-strument (SABER, v.1.07 and v.2.0), installed onboard the TIMED satellite. We compare temperatures meas-ured during satellite passes at distances under 500 km from the intersection of the spectrograph sighting line with the hydroxyl emitting layer (~87 km) and oxygen emitting layer (~95 km). The time criterion is 30 min. We observe that there is a seasonal dependence of the difference between the ground-based and satellite measurements. The data obtained using SABER v2.0 show good agreement with the temperatures measured with the infrared digital spectrograph. The analysis we carried out allows us to conclude that a series of rotational temperatures obtained at the Maimaga station can be used to study temperature variations on different time scales including long-term trends at the mesopause height

Retrieval of tropospheric BrO columns from TROPOMI and their validation using MAX-DOAS measurements in Ny-Ålesund

2021 ◽  
Author(s):  
Sora Seo ◽  
Andreas Richter ◽  
Anne-M. Blechschmidt ◽  
Ilias Bougoudis ◽  
Folkard Wittrock ◽  
...  
Keyword(s):  
Satellite Data ◽  
Atmospheric Chemistry ◽  
Multiple Linear Regression Model ◽  
Optical Absorption Spectroscopy ◽  
Retrieval Algorithm ◽  
Small Scale ◽  
Satellite Measurements ◽  
Scatter Plots ◽  
Total Column ◽  
Good Agreement

<p>Bromine compounds play an important role in atmospheric chemistry with respect to ozone chemistry and the resulting oxidation capacity. Large amounts of reactive bromine can be released by an autocatalytic heterogeneous mechanism called “bromine explosion”, and plumes of enhanced bromine monoxide (BrO) have been observed over polar sea ice regions by satellite measurements in spring. These enhancements of BrO columns result from increases in stratospheric or tropospheric bromine columns or both. As nadir-viewing UV-visible spectrometers have limited vertical resolution, it is not straight-forward to separate total BrO columns into tropospheric and stratospheric partial columns using satellite data.</p><p>In this study, an algorithm for tropospheric BrO retrieval from satellite measurements including TROPOMI, which provides much improved spatial resolution, was developed. The retrieval algorithm is based on the Differential Optical Absorption Spectroscopy (DOAS) technique and three different stratospheric correction methods were tested based on: output from a 3D atmospheric chemistry model, a climatology of stratospheric BrO profiles, and an empirical multiple linear regression model to separate the tropospheric partial column from the total column.</p><p>Retrieved tropospheric BrO columns from satellite measurements were compared with ground-based MAX-DOAS BrO observations at the NDACC station in Ny-Ålesund. The comparisons between ground-based and satellite measurements of tropospheric BrO show good agreement in both time-series and scatter plots, demonstrating the satellite retrieval algorithm is valid and applicable to study bromine release in the tropospheric layer. In particular, TROPOMI shows improved validation results for short distance collection compared to previous satellite data, which suggests the applicability of high-resolution satellite data on small-scale bromine explosion events observed during the MOSAiC campaign.</p>

scholarly journals sensitivity of middle atmospheric ozone to solar proton events: comparison between climate model and satellites

2021 ◽  
Author(s):  
Kenneth Nilsen ◽  
Antti Kero ◽  
Pekka Verronen ◽  
Monika Szelag ◽  
Niilo Kalakoski ◽  
...  
Keyword(s):  
Satellite Data ◽  
Climate Model ◽  
Solar Proton ◽  
Proton Flux ◽  
Data Sets ◽  
Atmospheric Ozone ◽  
Ion Chemistry ◽  
Solar Proton Events ◽  
Good Agreement

<p>Energetic particle precipitation (EPP) impact on the middle atmospheric ozone chemistry plays potentially an important role in the connection between space weather and Earth's climate system. A variant of the Whole Atmosphere Community Climate Model (WACCM-D) implements a detailed set of ionospheric D-region chemistry instead of a simple parameterization used in the earlier WACCM versions, allowing to capture the impact of EPP in more detail, thus improving the model for long-term climate studies. Here, we verify experimentally the ion chemistry of the WACCM-D by analysing the middle atmospheric ozone response to the EPP forcing during well-known solar proton events<span> </span>(SPEs). We use a multi-satellite approach to derive the middle atmospheric sensitivity for the SPE forcing as a statistical relation between the solar proton flux and the consequent ozone change. An identical sensitivity analysis is carried out for the WACCM-D model results, enabling one-to-one comparison with the results derived from the satellite observations. Our results show a good agreement in the sensitivity between satellites and the WACCM-D for nighttime conditions. For daytime conditions, we find a good agreement for the satellite data sets that include the largest SPEs (max proton flux >10^<span>4 </span> pfu). However, for those satellite data-sets with only minor and moderate SPEs, WACCM-D tends to underestimate the sensitivity in daytime conditions. In summary, the comparisons WACCM-D ion chemistry, combined with the transportation, demonstrates a realistic representation of the SPE sensitivity of ozone, and thus provides a conservative platform for long-term EPP impact studies.</p>

Sign in / Sign up

Export Citation Format

Share Document