scholarly journals On the correction of temperatures derived from meteor wind radars due to geomagnetic activity

2021 ◽  
Vol 2 ◽  
Author(s):  
C. M. Hall ◽  
M. G. Johnsen
Keyword(s):  
Geomagnetic Activity ◽  
Standard Method ◽  
High Latitude ◽  
Geographic Location ◽  
Temperature Measurements ◽  
Local Temperature ◽  
Geomagnetic Disturbances ◽  
Summer Temperatures ◽  
Low Costs ◽  
Meteor Trails

Abstract Radars used to observe meteor trails in the mesosphere deliver information on winds and temperature. Use of these radars is becoming a standard method for determining mesospheric dynamics and temperatures worldwide due to relatively low costs and ease of deployment. However, recent studies have revealed that temperatures may be overestimated in conditions such as high geomagnetic activity. The effect is thought to be most prevalent at high latitude, although this is not yet proven. Here, we demonstrate how temperatures might be corrected for geomagnetic effects; the demonstration is for a particular geographic location (Svalbard, 78°N, 16°E) because it is local geomagnetic disturbances that affects local temperature measurements, therefore requiring co-located instruments. We see that summer temperatures require a correction (reduction) of a few Kelvin, but winter estimates are more accurate.

Evolution of High-Latitude Geomagnetic Disturbances during the Magnetic Storm of July 22, 2009

2020 ◽  
Vol 60 (5) ◽  
pp. 547-558
Author(s):  
L. I. Gromova ◽  
N. G. Kleimenova ◽  
S. V. Gromov ◽  
L. M. Malysheva
Keyword(s):  
Magnetic Storm ◽  
High Latitude ◽  
Geomagnetic Disturbances

Explicit IMF By-dependence in geomagnetic activity

2021 ◽  
Author(s):  
Lauri Holappa ◽  
Timo Asikainen ◽  
Kalevi Mursula
Keyword(s):  
Solar Wind ◽  
Geomagnetic Activity ◽  
Space Weather ◽  
High Latitude ◽  
Coupling Function ◽  
Future Space ◽  
Weather Modeling ◽  
Southern High Latitude ◽  
Imf Clock Angle ◽  
The Imf

<p>The interaction of the solar wind with the Earth’s magnetic field produces geomagnetic activity, which is critically dependent on the orientation of the interplanetary magnetic field (IMF). Most solar wind coupling functions quantify this dependence on the IMF orientation with the so-called IMF clock angle in a way, which is symmetric with respect to the sign of the B<sub>y</sub> component. However, recent studies have shown that IMF B<sub>y</sub> is an additional, independent driver of high-latitude geomagnetic activity, leading to higher (weaker) geomagnetic activity in Northern Hemisphere (NH) winter for B<sub>y</sub> > 0 (B<sub>y</sub> < 0). For NH summer the dependence on the B<sub>y</sub> sign is reversed. We quantify the size of this explicit B<sub>y</sub>-effect with respect to the solar wind coupling function, both for northern and southern high-latitude geomagnetic activity. We show that for a given value of solar wind coupling function, geomagnetic activity is about 40% stronger for B<sub>y</sub> > 0 than for B<sub>y</sub> < 0 in NH winter. We also discuss recent advances in the physical understanding of the B<sub>y</sub>-effect. Our results highlight the importance of the IMF B<sub>y</sub>-component for space weather and must be taken into account in future space weather modeling.</p>

scholarly journals Geomagnetic control of the spectrum of traveling ionospheric disturbances based on data from a global GPS network

2001 ◽  
Vol 19 (7) ◽  
pp. 723-731 ◽  
Author(s):  
E. L. Afraimovich ◽  
E. A. Kosogorov ◽  
O. S. Lesyuta ◽  
I. I. Ushakov ◽  
A. F. Yakovets
Keyword(s):  
Geomagnetic Activity ◽  
Time Derivative ◽  
Power Spectra ◽  
Small Scale ◽  
Electron Content ◽  
Ionospheric Disturbances ◽  
Geomagnetic Disturbances ◽  
Absolute Level ◽  
Total Electron ◽  
Traveling Ionospheric Disturbances

Abstract. In this paper an attempt is made to verify the hypothesis of the role of geomagnetic disturbances as a factor in determining the intensity of traveling ionospheric disturbances (TIDs). To improve the statistical validity of the data, we have used the method involving a global spatial averaging of disturbance spectra of the total electron content (TEC). To characterize the TID intensity quantitatively, we suggest that a new global index of the degree of disturbance should be used, which is equal to the mean value of the rms variations in TEC within the selected range of spectral periods (of 20– 60 min, in the present case). The analysis has been made for a set of 100 to 300 GPS stations for 10 days with a different level of geomagnetic activity (Dst from 0 to –350 nT; the Kp index from 3 to 9). It was found that power spectra of daytime TEC variations in the range of 20–60 min periods under quiet conditions have a power-law form with the slope index k = –2.5. With an increase in the level of magnetic disturbance, there is an increase in the total intensity of TIDs, with a concurrent kink of the spectrum caused by an increase in oscillation intensity in the range of 20–60 min. The TEC variation amplitude is found to be smaller at night than during the daytime, and the spectrum decreases in slope, which is indicative of a disproportionate increase in the amplitude of the small-scale part of the spectrum. It was found that an increase in the level of geomagnetic activity is accompanied by an increase in the total intensity of TEC; however, it does not correlate with the absolute level of Dst, but rather with the value of the time derivative of Dst (a maximum correlation coefficient reaches –0.94). The delay of the TID response of the order of 2 hours is consistent with the view that TIDs are generated in auroral regions, and propagate equatorward with the velocity of about 300–400 m/s.Key words. Ionosphere (ionospheric disturbances; auroral ionosphere; equatorial ionopshere)

scholarly journals A chironomid-based reconstruction of summer temperatures in NW Iceland since AD 1650

2011 ◽  
Vol 75 (3) ◽  
pp. 451-460 ◽  
Author(s):  
P.G. Langdon ◽  
C.J. Caseldine ◽  
I.W. Croudace ◽  
S. Jarvis ◽  
S. Wastegård ◽  
...  
Keyword(s):  
Temperature Reconstruction ◽  
Summer Temperature ◽  
Temperature Measurements ◽  
Ice Age ◽  
Data Set ◽  
Ice Cap ◽  
Catchment Disturbance ◽  
Summer Temperatures ◽  
Percentage Abundance ◽  
Instrumental Temperature

AbstractFew studies currently exist that aim to validate a proxy chironomid-temperature reconstruction with instrumental temperature measurements. We used a reconstruction from a chironomid percentage abundance data set to produce quantitative summer temperature estimates since AD 1650 for NW Iceland through a transfer function approach, and validated the record against instrumental temperature measurements from Stykkishólmur in western Iceland. The core was dated through Pb-210, Cs-137 and tephra analyses (Hekla 1693) which produced a well-constrained dating model across the whole study period. Little catchment disturbance, as shown through geochemical (Itrax) and loss-on-ignition data, throughout the period further reinforce the premise that the chironomids were responding to temperature and not other catchment or within-lake variables. Particularly cold phases were identified between AD 1683–1710, AD 1765–1780 and AD 1890–1917, with relative drops in summer temperatures in the order of 1.5–2°C. The timing of these cold phases agree well with other evidence of cooler temperatures, notably increased extent of Little Ice Age (LIA) glaciers. Our evidence suggests that the magnitude of summer temperature cooling (1.5–2°C) was enough to force LIA Icelandic glaciers into their maximum Holocene extent, which is in accordance with previous modelling experiments for an Icelandic ice cap (Langjökull).

High-latitude geomagnetic disturbances during the initial phase of a recurrent magnetic storm (from February 27 to March 2, 2008)

2011 ◽  
Vol 51 (6) ◽  
pp. 730-740 ◽  
Author(s):  
N. G. Kleimenova ◽  
O. V. Kozyreva ◽  
J. Manninen ◽  
T. Raita ◽  
T. A. Kornilova ◽  
...  
Keyword(s):  
Magnetic Storm ◽  
High Latitude ◽  
Initial Phase ◽  
Geomagnetic Disturbances

scholarly journals Studying of solar-terrestrial connections in the dynamics of the surface atmospheric electric field

2020 ◽  
Vol 196 ◽  
pp. 01010
Author(s):  
Tatyana Kudrinskaya ◽  
Gennady Kupovykh ◽  
Anatoly Adzhiev ◽  
Bulat Zainetdinov
Keyword(s):  
Electric Field ◽  
High Altitude ◽  
Geomagnetic Activity ◽  
Field Intensity ◽  
High Latitude ◽  
Electric Field Intensity ◽  
Atmospheric Electric Field ◽  
Surface Atmosphere

The paper presents the results of the analysis of variations in the electric field intensity of the surface atmosphere obtained in high-latitude, high-altitude and lowland observation points, together with the parameters of solar and geomagnetic activity.

scholarly journals Transmission Lines in Poland and Space Weather Effects

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2359 ◽  
Author(s):  
Agnieszka Gil ◽  
Renata Modzelewska ◽  
Szczepan Moskwa ◽  
Agnieszka Siluszyk ◽  
Marek Siluszyk ◽  
...  
Keyword(s):  
Solar Activity ◽  
Geomagnetic Activity ◽  
Space Weather ◽  
Transmission Lines ◽  
Cumulative Effect ◽  
Activity Cycle ◽  
Activity Level ◽  
Geomagnetic Disturbances ◽  
Time Intervals ◽  
Weather Effects

We analyze the solar influence of space weather events on Polish energy infrastructure via geomagnetic disturbances. We consider two time intervals of very different levels of solar activity (SA) in the course of the solar activity cycle 24: 2010—an early rising phase of SA, near the solar minimum and 2014—solar maximum. From the total number of electrical grid failures, we extract almost five thousand failures in 2010 and more than ten thousand in 2014, which could be related to space weather effects. We analyze data of failures having unidentified causes, failures coupled with the aging of transmission network elements and electronic devices, which appeared during the time intervals of enhanced geomagnetic activity. We show that around the times of increasing geomagnetic activity level, the amount of transmission lines failures in the groups mentioned above grows, but mostly with some delay. It might be connected to some cumulative effect due to the result of transient states and their propagation in the distribution network. Although we do not exclude that the other factors may play a role, the solar-originating disturbances strengthen these effects.

Hybrid Nanocomposites Formed by Lanthanide Nanoparticles in Zr-MOF for Local Temperature Measurements during Catalytic Reactions

2021 ◽  
Author(s):  
Himanshu Sekhar Jena ◽  
Hannes Rijckaert ◽  
Chidharth Krishnaraj ◽  
Isabel Van Driessche ◽  
Pascal Van Der Voort ◽  
...  
Keyword(s):  
Catalytic Reactions ◽  
Temperature Measurements ◽  
Hybrid Nanocomposites ◽  
Local Temperature
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