scholarly journals Gravity-wave-perturbed wind shears derived from SABER temperature observations

2020 ◽  
Vol 20 (22) ◽  
pp. 14437-14456
Author(s):  
Xiao Liu ◽  
Jiyao Xu ◽  
Jia Yue ◽  
Hanli Liu
Keyword(s):  
Sounding Rocket ◽  
High Latitudes ◽  
Mesopause Region ◽  
Sounding Rockets ◽  
Model Simulations ◽  
Broadband Emission ◽  
Ionospheric Electrodynamics ◽  
Wind Shears ◽  
Large Wind ◽  
Cutoff Criterion

Abstract. Large wind shears around the mesopause region play an important role in atmospheric neutral dynamics and ionospheric electrodynamics. Based on previous observations using sounding rockets, lidars, radars, and model simulations, large shears are mainly attributed to gravity waves (GWs) and modulated by tides (Liu, 2017). Based on the dispersion and polarization relations of linear GWs and the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) temperature data from 2002 to 2019, a method of deriving GW-perturbed wind shears is proposed. The zonal-mean GW-perturbed shears have peaks (13–17 ms−1 km−1) at around the mesopause region, i.e., at z = 90–100 km at most latitudes and at z = 80–90 km around the cold summer mesopause. This latitude–height pattern is robust over the 18 years and agrees with model simulations. The magnitudes of the GW-perturbed shears exhibit year-to-year variations and agree with the lidar and sounding rocket observations in a climatological sense but are 60 %–70 % of the model results in the zonal-mean sense. The GW-perturbed shears are hemispherically asymmetric and have strong annual oscillation (AO) at around 80 km (above 92 km) at the northern (southern) middle and high latitudes. At middle to high latitudes, the peaks of AO shift from winter to summer and then to winter again with increasing height. However, these GW-perturbed shears may be overestimated because the GW propagation direction cannot be resolved by the method and may be underestimated due to the observational filter, sampling distance, and cutoff criterion of the vertical wavelength of GWs.

scholarly journals Gravity Waves induced Wind Shears Derived from SABER Temperature Observations

2020 ◽  
Author(s):  
Xiao Liu ◽  
Jiyao Xu ◽  
Jia Yue ◽  
Hanli Liu
Keyword(s):  
Gravity Waves ◽  
Sounding Rocket ◽  
High Latitudes ◽  
Mesopause Region ◽  
Sounding Rockets ◽  
Model Simulations ◽  
Ionospheric Electrodynamics ◽  
Wind Shears ◽  
Large Wind ◽  
Cutoff Criterion

Abstract. Large wind shears around the mesopause region play important roles in atmospheric neutral dynamics and ionospheric electrodynamics. Based on previous observations using sounding rockets, lidars, radars and model simulations, large shears are mainly attributed to gravity waves (GWs) and modulated by tides (Liu, 2017). Based on the dispersion and polarization relations of linear GWs and the SABER temperature data from 2002 to 2019, a method of deriving GW-induced wind shears is proposed. The zonal mean GW-induced shears have peaks (13–17 ms−1 km−1) at around the mesopause region, i.e., at z = 90–100 km at most latitudes and at z = 80–90 km around the cold summer mesopause. This latitude-height pattern is robust over the 18 years and coincides with model simulations. The magnitudes of the GW-induced shears exhibit year-to-year variations and coincide with the lidar and sounding rocket observations on climatology sense but are 60–70 % of the model results in the zonal mean sense. The GW-induced shears are hemispheric asymmetric and have strong annual oscillation (AO) at around 80 km (above 92 km) at the northern (southern) middle and high latitudes. At middle to high latitudes, the peaks of AO shift from winter to summer and then to winter again with increasing height. However, these GW-induced shears may be overestimated because the GW propagation direction cannot be resolved by the method and may be underestimated due to the observational filter, sampling distance and cutoff criterion of the vertical wavelength of GWs.

scholarly journals Data Analysis of Upper Atmosphere Temperature Detected by Sounding Rockets in China

2017 ◽  
Vol 34 (3) ◽  
pp. 555-565 ◽  
Author(s):  
J. W. Li ◽  
Z. Sheng ◽  
Z. Q. Fan ◽  
S. D. Zhou ◽  
W. L. Shi
Keyword(s):  
Temperature Data ◽  
Upper Atmosphere ◽  
Statistical Characteristics ◽  
Sounding Rocket ◽  
Temperature Profiles ◽  
Sounding Rockets ◽  
Temperature Changes ◽  
Broadband Emission ◽  
Atmosphere Temperature ◽  
The Mean

AbstractSounding rockets launched by China have collected data on the upper atmosphere for nearly 50 years. In this work, the data accuracy and variable characteristics of upper atmosphere temperature data, gathered at heights of 20–60 km over Jiuquan, China, during 1974–2014, were analyzed. The relative accuracy of sounding rocket temperature data was determined by comparing the data with Mass Spectrometer and Incoherent Scatter (MSIS) model data by season, and with Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) from the Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics (TIMED) satellite by year. The sounding rocket temperature data showed differences from MSIS in every season, with the minimum difference occurring in summer, the next smallest difference in winter, and the maximum difference occurring in autumn. The sounding rocket data showed smaller differences from the SABER data, although the deviation still fluctuated depending on the date and hour of the observations. In addition, the temperature distributions of the temperature profiles were examined at different times at the same heights. By linearly fitting the mean temperature profiles of each season, the statistical characteristics of the temperature changes with height were explored.

The North Atlantic Ocean as a Modulator of Vegetation Greening/Browning in the Northern High Latitudes?

2021 ◽  
Author(s):  
Leonard F. Borchert ◽  
Alexander J. Winkler
Keyword(s):  
Climate Variability ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
Internal Variability ◽  
Dominant Mode ◽  
High Latitudes ◽  
Model Simulations ◽  
Internal Climate Variability ◽  
The North ◽  
The North Atlantic

<p>Vegetation in the northern high latitudes shows a characteristic pattern of persistent changes as documented by multi-decadal satellite observations. The prevailing explanation that these mainly increasing trends (greening) are a consequence of external CO<sub>2</sub> forcing, i.e., due to the ubiquitous effect of CO2-induced fertilization and/or warming of temperature-limited ecosystems, however does not explain why some areas also show decreasing trends of vegetation cover (browning). We propose here to consider the dominant mode of multi-decadal internal climate variability in the north Atlantic region, the Atlantic Multidecadal Variability (AMV), as the missing link in the explanation of greening and browning trend patterns in the northern high latitudes. Such a link would also imply potential for decadal predictions of ecosystem changes in the northern high latitudes.</p><p>An analysis of observational and reanalysis data sets for the period 1979-2019 shows that locations characterized by greening trends largely coincide with warming summer temperature and increasing precipitation. Wherever either cooling or decreasing precipitation occurs, browning trends are observed over this period. These precipitation and temperature patterns are significantly correlated with a North Atlantic sea surface temperature index that represents the AMV signal, indicating its role in modulating greening/browning trend patterns in the northern high latitudes.</p><p>Using two large ensembles of coupled Earth system model simulations (100 members of MPI-ESM-LR Grand Ensemble and 32 members of the IPSL-CM6A-LR Large Ensemble), we separate the greening/browning pattern caused by external CO<sub>2</sub> forcing from that caused by internal climate variability associated with the AMV. These sets of model simulations enable a clean separation of the externally forced signal from internal variability. While the greening and browning patterns in the simulations do not agree with observations in terms of magnitude and location, we find consistent internally generated greening/browning patterns in both models caused by changes in temperature and precipitation linked to the AMV signal. These greening/browning trend patterns are of the same magnitude as those caused by the external forcing alone. Our work therefore shows that internally-generated changes of vegetation in the northern lands, driven by AMV, are potentially as large as those caused by external CO<sub>2</sub> forcing. We thus argue that the observed pattern of greening/browning in the northern high latitudes could originate from the combined effect of rising CO<sub>2</sub> as well as the AMV.</p>

scholarly journals Climate change between the mid and late Holocene in northern high latitudes – Part 2: Model-data comparisons

2010 ◽  
Vol 6 (5) ◽  
pp. 609-626 ◽  
Author(s):  
Q. Zhang ◽  
H. S. Sundqvist ◽  
A. Moberg ◽  
H. Körnich ◽  
J. Nilsson ◽  
...  
Keyword(s):  
Sea Ice ◽  
Climate Models ◽  
Barents Sea ◽  
Arctic Region ◽  
Summer Temperature ◽  
The Arctic ◽  
High Latitudes ◽  
Climate Response ◽  
Model Data ◽  
Model Simulations

Abstract. The climate response over northern high latitudes to the mid-Holocene orbital forcing has been investigated in three types of PMIP (Paleoclimate Modelling Intercomparison Project) simulations with different complexity of the modelled climate system. By first undertaking model-data comparison, an objective selection method has been applied to evaluate the capability of the climate models to reproduce the spatial response pattern seen in proxy data. The possible feedback mechanisms behind the climate response have been explored based on the selected model simulations. Subsequent model-model comparisons indicate the importance of including the different physical feedbacks in the climate models. The comparisons between the proxy-based reconstructions and the best fit selected simulations show that over the northern high latitudes, summer temperature change follows closely the insolation change and shows a common feature with strong warming over land and relatively weak warming over ocean at 6 ka compared to 0 ka. Furthermore, the sea-ice-albedo positive feedback enhances this response. The reconstructions of temperature show a stronger response to enhanced insolation in the annual mean temperature than winter and summer temperature. This is verified in the model simulations and the behaviour is attributed to the larger contribution from the large response in autumn. Despite a smaller insolation during winter at 6 ka, a pronounced warming centre is found over Barents Sea in winter in the simulations, which is also supported by the nearby northern Eurasian continental and Fennoscandian reconstructions. This indicates that in the Arctic region, the response of the ocean and the sea ice to the enhanced summer insolation is more important for the winter temperature than the synchronous decrease of the insolation.

Auroral electrodynamics---investigation by a dual sounding rocket experiment

2020 ◽  
Author(s):  
Hassanali Akbari ◽  
Robert Pfaff ◽  
Keyword(s):  
Electric Fields ◽  
Sounding Rocket ◽  
Sounding Rockets ◽  
Neutral Winds ◽  
Incoherent Scatter ◽  
Ac Electric Fields ◽  
Numerical Studies ◽  
Rocket Experiment ◽  
N Wave

<p>We present results from a 2017 sounding rocket experiment in which two NASA sounding rockets were simultaneously launched into the auroral ionosphere. The rockets included comprehensive instrumentation to measure DC and AC electric fields, magnetic fields, energetic particles, plasma density, and neutral winds, among other parameters, and achieved apogees of 190 and 330 km. This unprecedented collection of in-situ measurements obtained at two altitudes over an auroral arc, along with conjugate ground-based measurements by the Poker Flat incoherent scatter radar and all-sky cameras, enable us to investigate the behavior of an aurora arc and its associated electrodynamics. A prominent feature of our observations is the presence of localized, large-amplitude Alfvén wave structures observed in both the electric field and magnetometers at altitudes as low as 190 km in the vicinity of up- and down-ward current regions. The observations are discussed in the context of ionospheric feedback instability. The results are compared to predictions of previously published numerical studies and other sounding rocket observations.</p>

Simultaneous atomic and ion layer enhancements observed in the mesopause region over Arecibo during the Coqui II Sounding Rocket Campaign

2000 ◽  
Vol 27 (4) ◽  
pp. 449-452 ◽  
Author(s):  
J. S. Friedman ◽  
S. A. González ◽  
C. A. Tepley ◽  
Q. Zhou ◽  
M. P. Sulzer ◽  
...  
Keyword(s):  
Sounding Rocket ◽  
Mesopause Region

scholarly journals A reactive control system for a partially guided small sounding rocket

2019 ◽  
Vol 304 ◽  
pp. 07011
Author(s):  
Cristian Emil Constantinescu
Keyword(s):  
Flight Control ◽  
Sounding Rocket ◽  
Reactive Control ◽  
Dead Weight ◽  
Sounding Rockets ◽  
Stability And Control ◽  
Second Stage ◽  
Upper Stage ◽  
The Stability ◽  
And Control

Most small sounding rockets are unguided vehicle. Stability is solved aerodynamically using fins and/or rapidly spinning the vehicle and trajectory is determined by the azimuth and elevation of the launch pad as the rocket usually fly a gravity turn. Access to upper atmosphere usually require two or three stages and the presence of fins on the upper stages inflict a penalty on the stability of the launcher in the start configuration. The paper presents a modification made to an existing launcher suggested by the need to add dead weight for stability when flying small payloads. By eliminating the fins from the second stage and using a RCS for active stability and control of the upper stage several opportunities arise: the aerodynamic configuration is simpler and the stability in the start configuration improved, drag is reduced a bit, non-gravity turn evolutions are possible and special payload requested attitudes (mainly orienting a camera towards ground) are conceivable. Of course, this require a new OBC with enhanced sensors and new navigation and flight control algorithms.

scholarly journals Solidification Furnace Developed for Sounding Rockets: Rio Verde Mission

2019 ◽  
Author(s):  
Rafael Cardoso Toledo ◽  
Manuel Francisco Ribeiro ◽  
Irajá Newton Bandeira ◽  
Chen Ying An
Keyword(s):  
Parabolic Flight ◽  
Space Research ◽  
Metal Alloys ◽  
Sounding Rocket ◽  
Sounding Rockets ◽  
Space Research Institute ◽  
Solidification Furnace ◽  
Research Institute

Brazil has a Microgravity Program mainly based on experiments using sounding rockets. Up to now, four missions have been carried out with approximately 35 experiments submitted in total. In all flights, the Associate Laboratory of Sensors and Materials of the Brazilian Space Research Institute (LABAS/INPE) participated with a fast solidification furnace, capable of producing temperatures up to 900 °C, which was tested with semiconductor and metal alloys. This paper describes the construction and the performance of that furnace during the last parabolic flight, Rio Verde Mission, occurred in 2016. The solidification furnace is now qualified and ready to be used by other institutions in sounding rocket flights.

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