scholarly journals Aspect sensitivity of polar mesosphere summer echoes based on ESRAD MST radar measurements in Kiruna, Sweden in 1997–2010

2012 ◽  
Vol 30 (3) ◽  
pp. 457-465 ◽  
Author(s):  
M. Smirnova ◽  
E. Belova ◽  
S. Kirkwood
Keyword(s):  
Complete Information ◽  
Analysis Technique ◽  
Altitude Dependence ◽  
Absolute Strength ◽  
Summer Echoes ◽  
Polar Mesosphere Summer Echoes ◽  
Vertical Beam ◽  
Radar Measurements ◽  
Full Correlation Analysis ◽  
Aspect Sensitivity

Abstract. Aspect sensitivities of polar mesosphere summer echoes (PMSE) measured with the ESRAD 50 MHz radar in 1997–2010 are studied using the full correlation analysis technique. Half of PMSE detected each year are found to be highly aspect sensitive. Yearly median values of the aspect sensitivity parameter θs, characterising the half-width of the scatterers' polar diagram, are 2.9–3.7° depending on the year. The other half of the PMSE have θs values larger than 9–11° and cannot be evaluated using the ESRAD vertical beam only. PMSE aspect sensitivity reveals an altitude dependence, namely, the scatter becomes more isotropic with increasing height. This result is consistent with that reported in other studies. No dependence of PMSE aspect sensitivity on backscattered power for any year was identified. In the paper the limitations of the in-beam and off-vertical beam methods for estimation of PMSE aspect sensitivity are discussed. We conclude that both methods should be combined in order to get complete information about PMSE aspect sensitivity and to estimate correctly PMSE absolute strength.

scholarly journals Coincident measurements of PMSE and NLC above ALOMAR (69° N, 16° E) by radar and lidar from 1999–2008

2010 ◽  
Vol 10 (10) ◽  
pp. 25081-25116 ◽  
Author(s):  
N. Kaifler ◽  
G. Baumgarten ◽  
J. Fiedler ◽  
R. Latteck ◽  
F.-J. Lübken ◽  
...  
Keyword(s):  
Lower Layer ◽  
Occurrence Rate ◽  
Noctilucent Clouds ◽  
Raman Lidar ◽  
Vhf Radar ◽  
Lidar Measurements ◽  
Summer Echoes ◽  
Polar Mesosphere Summer Echoes ◽  
Radar Measurements ◽  
Sublimation Rates

Abstract. Polar Mesosphere Summer Echoes (PMSE) and Noctilucent Clouds (NLC) have been routinely measured at the ALOMAR research facility in Northern Norway (69° N, 16° E) by lidar and radar, respectively. 2900 h of lidar measurements by the ALOMAR Rayleigh/Mie/Raman lidar were combined with almost 18 000 h of radar measurements by the ALWIN VHF radar, all taken during the years 1999 to 2008, to study simultaneous and common-volume observations of both phenomena. PMSE and NLC are known from both theory and observations to be positively linked. We quantify the occurrences of PMSE and/or NLC and relations in altitude, especially with respect to the lower layer boundaries. The PMSE occurrence rate is with 75.3% considerably higher than the NLC occurrence rate of 19.5%. For overlapping PMSE and NLC observations, we confirm the coincidence of the lower boundaries and find a standard deviation of 1.26 km, hinting at very fast sublimation rates. However, 10.1% of all NLC measurements occur without accompanying PMSE. Comparison of occurrence rates with solar zenith angle reveals that NLC without PMSE mostly occur around midnight indicating that the ice particles were invisible to the radar due to the reduced electron density.

scholarly journals Coincident measurements of PMSE and NLC above ALOMAR (69° N, 16° E) by radar and lidar from 1999–2008

2011 ◽  
Vol 11 (4) ◽  
pp. 1355-1366 ◽  
Author(s):  
N. Kaifler ◽  
G. Baumgarten ◽  
J. Fiedler ◽  
R. Latteck ◽  
F.-J. Lübken ◽  
...  
Keyword(s):  
Lower Layer ◽  
Occurrence Rate ◽  
Noctilucent Clouds ◽  
Raman Lidar ◽  
Vhf Radar ◽  
Lidar Measurements ◽  
Summer Echoes ◽  
Polar Mesosphere Summer Echoes ◽  
Radar Measurements ◽  
Sublimation Rates

Abstract. Polar Mesosphere Summer Echoes (PMSE) and Noctilucent Clouds (NLC) have been routinely measured at the ALOMAR research facility in Northern Norway (69° N, 16° E) by lidar and radar, respectively. 2900 h of lidar measurements by the ALOMAR Rayleigh/Mie/Raman lidar were combined with almost 18 000 h of radar measurements by the ALWIN VHF radar, all taken during the years 1999 to 2008, to study simultaneous and common-volume observations of both phenomena. PMSE and NLC are known from both theory and observations to be positively linked. We quantify the occurrences of PMSE and/or NLC and relations in altitude, especially with respect to the lower layer boundaries. The PMSE occurrence rate is with 75.3% considerably higher than the NLC occurrence rate of 19.5%. For overlapping PMSE and NLC observations, we confirm the coincidence of the lower boundaries and find a standard deviation of 1.26 km, hinting at very fast sublimation rates. However, 10.1% of all NLC measurements occur without accompanying PMSE. Comparison of occurrence rates with solar zenith angle reveals that NLC without PMSE mostly occur around midnight indicating that the ice particles were not detected by the radar due to the reduced electron density.

scholarly journals Aspect sensitivity measurements of polar mesosphere summer echoes using coherent radar imaging

2002 ◽  
Vol 20 (2) ◽  
pp. 213-223 ◽  
Author(s):  
P. B. Chilson ◽  
T.-Y. Yu ◽  
R. D. Palmer ◽  
S. Kirkwood
Keyword(s):  
Middle Atmosphere ◽  
Radar Imaging ◽  
Brightness Distribution ◽  
High Signal ◽  
Vhf Radar ◽  
Radio Science ◽  
Summer Echoes ◽  
Polar Mesosphere Summer Echoes ◽  
Coherent Radar ◽  
Aspect Sensitivity

Abstract. The Esrange VHF radar (ESRAD), located in northern Sweden (67.88° N, 21.10° E), has been used to investigate polar mesosphere summer echoes (PMSE). During July and August of 1998, coherent radar imaging (CRI) was used to study the dynamic evolution of PMSE with high temporal and spatial resolution. A CRI analysis provides an estimate of the angular brightness distribution within the radar’s probing volume. The brightness distribution is directly related to the radar reflectivity. Consequently, these data are used to investigate the aspect sensitivity of PMSE. In addition to the CRI analysis, the full correlation analysis (FCA) is used to derive estimates of the prevailing three-dimensional wind associated with the observed PMSE. It is shown that regions within the PMSE with enhanced aspect sensitivity have a correspondingly high signal-to-noise ratio (SNR). Although this relationship has been investigated in the past, the present study allows for an estimation of the aspect sensitivity independent of the assumed scattering models and avoids the complications of comparing echo strengths from vertical and off-vertical beams over large horizontal separations, as in the Doppler Beam Swinging (DBS) method. Regions of enhanced aspect sensitivity were additionally shown to correlate with the wave-perturbation induced downward motions of air parcels embedded in the PMSE.Key words. Ionosphere (polar ionosphere) Meteorology and Atmospheric Dynamics (middle atmosphere dynamics) Radio Science (Interferometry)

scholarly journals Studies of polar mesosphere summer echoes by VHF radar and rocket probes

1994 ◽  
Vol 14 (9) ◽  
pp. 139-148 ◽  
Author(s):  
U.-P. Hoppe ◽  
T.A. Blix ◽  
E.V. Thrane ◽  
F.-J. Lübken ◽  
J.Y.N. Cho ◽  
...  
Keyword(s):  
Vhf Radar ◽  
Summer Echoes ◽  
Polar Mesosphere Summer Echoes

scholarly journals The Coplane Analysis Technique for Three-Dimensional Wind Retrieval Using the HIWRAP Airborne Doppler Radar

2015 ◽  
Vol 54 (3) ◽  
pp. 605-623 ◽  
Author(s):  
Anthony C. Didlake ◽  
Gerald M. Heymsfield ◽  
Lin Tian ◽  
Stephen R. Guimond
Keyword(s):  
Global Optimization ◽  
Doppler Radar ◽  
Three Dimensional ◽  
Optimization Method ◽  
Vertical Wind ◽  
Wind Component ◽  
Global Optimization Method ◽  
Analysis Technique ◽  
Radar Measurements ◽  
Cross Track

AbstractThe coplane analysis technique for mapping the three-dimensional wind field of precipitating systems is applied to the NASA High-Altitude Wind and Rain Airborne Profiler (HIWRAP). HIWRAP is a dual-frequency Doppler radar system with two downward-pointing and conically scanning beams. The coplane technique interpolates radar measurements onto a natural coordinate frame, directly solves for two wind components, and integrates the mass continuity equation to retrieve the unobserved third wind component. This technique is tested using a model simulation of a hurricane and compared with a global optimization retrieval. The coplane method produced lower errors for the cross-track and vertical wind components, while the global optimization method produced lower errors for the along-track wind component. Cross-track and vertical wind errors were dependent upon the accuracy of the estimated boundary condition winds near the surface and at nadir, which were derived by making certain assumptions about the vertical velocity field. The coplane technique was then applied successfully to HIWRAP observations of Hurricane Ingrid (2013). Unlike the global optimization method, the coplane analysis allows for a transparent connection between the radar observations and specific analysis results. With this ability, small-scale features can be analyzed more adequately and erroneous radar measurements can be identified more easily.

Using polar mesosphere summer echoes and stratospheric/mesospheric winds to explain summer mesopause jumps in Antarctica

2017 ◽  
Vol 162 ◽  
pp. 106-115 ◽  
Author(s):  
Franz-Josef Lübken ◽  
Ralph Latteck ◽  
Erich Becker ◽  
Josef Höffner ◽  
Damian Murphy
Keyword(s):  
Summer Echoes ◽  
Polar Mesosphere Summer Echoes

scholarly journals Imaging of Polar Mesosphere Summer Echoes with the 450 MHz Poker Flat Advanced Modular Incoherent Scatter Radar

2007 ◽  
Vol 34 (20) ◽  
Author(s):  
M. J. Nicolls ◽  
C. J. Heinselman ◽  
E. A. Hope ◽  
S. Ranjan ◽  
M. C. Kelley ◽  
...  
Keyword(s):  
Incoherent Scatter Radar ◽  
Incoherent Scatter ◽  
Scatter Radar ◽  
Summer Echoes ◽  
Polar Mesosphere Summer Echoes
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