The CME arrival prediction with the Effective Acceleration Model: Further testing with heliospheric imaging observations

2021 ◽  
Author(s):  
Evangelos Paouris ◽  
Angelos Vourlidas ◽  
Athanasios Papaioannou ◽  
Anastasios Anastasiadis
Keyword(s):  
Interplanetary Medium ◽  
Field Of View ◽  
Time Of Arrival ◽  
Test Cases ◽  
Constant Acceleration ◽  
Acceleration Model ◽  
Open Issue ◽  
Mass Ejection ◽  
First Time ◽  
Ambient Solar Wind

<p>The estimation of the Coronal Mass Ejection (CME) arrival is an open issue in the field of Space Weather. Many models have been developed to predict Time-of-Arrival (ToA). In this work, we utilize an updated version of the Effective Acceleration Model (EAM) to calculate the ToA. The EAM predicts the ToA of the CME-driven shock and the sheath's average speed at 1 AU. The model assumes that the interaction between the ambient solar wind and the interplanetary CME (ICME) results in constant acceleration or deceleration. We recently compared EAM against ENLIL and drag based models (DBEM) with a sample of 16 CMEs. We confirmed the well-known fact that the deceleration of fast ICMEs in the interplanetary medium is not captured by most models. We study further the deceleration of fast ICMEs by introducing, for the first time, wide-angle observations by the STEREO heliospheric imagers into the EAM model. The speed profiles for some test cases show deceleration in the interplanetary medium at greater distances compared with the field-of-view of the coronagraphs.</p>

scholarly journals Photospheric magnetic field of an eroded-by-solar-wind coronal mass ejection

2016 ◽  
Vol 12 (S327) ◽  
pp. 67-70
Author(s):  
J. Palacios ◽  
C. Cid ◽  
E. Saiz ◽  
A. Guerrero
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Coronal Mass Ejection ◽  
Coronal Hole ◽  
Interplanetary Medium ◽  
Flux Rope ◽  
Magnetic Characteristics ◽  
Interplanetary Coronal Mass Ejection ◽  
Fast Wind ◽  
Mass Ejection

AbstractWe have investigated the case of a coronal mass ejection that was eroded by the fast wind of a coronal hole in the interplanetary medium. When a solar ejection takes place close to a coronal hole, the flux rope magnetic topology of the coronal mass ejection (CME) may become misshapen at 1 AU as a result of the interaction. Detailed analysis of this event reveals erosion of the interplanetary coronal mass ejection (ICME) magnetic field. In this communication, we study the photospheric magnetic roots of the coronal hole and the coronal mass ejection area with HMI/SDO magnetograms to define their magnetic characteristics.

Studies of winds and weather during migrations of Simulium damnosum Theobald (Diptera: Simuliidae), the vector of onchocerciasis in West Africa

1980 ◽  
Vol 70 (4) ◽  
pp. 693-716 ◽  
Author(s):  
J. I. Magor ◽  
L. J. Rosenberg
Keyword(s):  
West Africa ◽  
Time Of Arrival ◽  
Convergence Zone ◽  
Gonotrophic Cycle ◽  
Inter Tropical Convergence Zone ◽  
The North ◽  
Simulium Damnosum ◽  
Host Seeking ◽  
First Time ◽  
High Winds

AbstractReports of the presence and absence of biting by Simulium damnosum Theo. in the Volta River Basin in 1962, 1966 and 1975 were used to identify occasions when sites were invaded by parous and nulliparous females. Circumstantial evidence suggests that this insect is a wind-borne migrant, and the weather before and during some of these invasions was examined. Although most invasions studied took place south of the Inter-tropical Convergence Zone, for the first time evidence is presented suggesting that migration also takes place to the north of this zone. Immigrants were captured at the invaded sites only when light winds or calms were present. This cannot, however, be used as proof that S. damnosum migrates and lands only where winds are light or it is calm because host-seeking is inhibited by high winds and the time of arrival, as opposed to capture on a host, is unknown. Until the factors initiating emigration, as well as the height, duration and number of flights in each gonotrophic cycle and the time of immigration are known, the present findings cannot be tested rigorously nor can wind records be used to trace the source of immigrants.

scholarly journals Technical Note: Regularization performances with the error consistency method in the case of retrieved atmospheric profiles

2006 ◽  
Vol 6 (6) ◽  
pp. 13307-13321
Author(s):  
S. Ceccherini ◽  
C. Belotti ◽  
B. Carli ◽  
P. Raspollini ◽  
M. Ridolfi
Keyword(s):  
Regularization Parameter ◽  
Technical Note ◽  
Field Of View ◽  
Regularization Methods ◽  
Vertical Profiles ◽  
Vertical Resolution ◽  
Vertical Field ◽  
The Stability ◽  
First Time ◽  
Consistency Method

Abstract. The retrieval of concentration vertical profiles of atmospheric constituents from spectroscopic measurements is often an ill-conditioned problem and regularization methods are frequently used to improve its stability. Recently a new method, that provides a good compromise between precision and vertical resolution, was proposed to determine analytically the value of the regularization parameter. This method is applied for the first time to real measurements with its implementation in the operational retrieval code of the satellite limb-emission measurements of the MIPAS instrument and its performances are quantitatively analyzed. The adopted regularization improves the stability of the retrieval providing smooth profiles without major degradation of the vertical resolution. In the analyzed measurements the retrieval procedure provides a vertical resolution that, in the troposphere and low stratosphere, is smaller than the vertical field of view of the instrument.

scholarly journals Shadow monochromatic backlighting: Large-field high resolution X-ray shadowgraphy with improved spectral tunability

2001 ◽  
Vol 19 (2) ◽  
pp. 285-293 ◽  
Author(s):  
T.A. PIKUZ ◽  
A. YA. FAENOV ◽  
M. FRAENKEL ◽  
A. ZIGLER ◽  
F. FLORA ◽  
...  
Keyword(s):  
High Resolution ◽  
High Spatial Resolution ◽  
Field Of View ◽  
Large Field ◽  
X Ray ◽  
Traditional Scheme ◽  
Wide Range ◽  
Wide Wavelength Range ◽  
Bent Crystals ◽  
First Time

The shadow monochromatic backlighting (SMB) scheme, a modification of the well-known soft X-ray monochromatic backlighting scheme, is proposed. It is based on a spherical crystal as the dispersive element and extends the traditional scheme by allowing one to work with a wide range of Bragg angles and thus in a wide spectral range. The advantages of the new scheme are demonstrated experimentally and supported numerically by ray-tracing simulations. In the experiments, the X-ray backlighter source is a laser-produced plasma, created by the interaction of an ultrashort pulse, Ti:Sapphire laser (120 fs, 3–5 mJ, 1016 W/cm2 on target) or a short wavelength XeCl laser (10 ns, 1–2 J, 1013 W/cm2 on target) with various solid targets (Dy, Ni + Cr, BaF2). In both experiments, the X-ray sources are well localized spatially (∼20 μm) and are spectrally tunable in a relatively wide wavelength range (λ = 8–15 Å). High quality monochromatic (δλ/λ ∼ 10−5–10−3) images with high spatial resolution (up to ∼4 μm) over a large field of view (a few square millimeters) were obtained. Utilization of spherically bent crystals to obtain high-resolution, large field, monochromatic images in a wide range of Bragg angles (35° < Θ < 90°) is demonstrated for the first time.

scholarly journals High-speed stereoscopy of aurora

2016 ◽  
Vol 34 (1) ◽  
pp. 41-44 ◽  
Author(s):  
R. Kataoka ◽  
Y. Fukuda ◽  
H. A. Uchida ◽  
H. Yamada ◽  
Y. Miyoshi ◽  
...  
Keyword(s):  
High Speed ◽  
Field Of View ◽  
Stereoscopic Imaging ◽  
The North ◽  
Base Distance ◽  
First Time ◽  
Magnetic Zenith

Abstract. We performed 100 fps stereoscopic imaging of aurora for the first time. Two identical sCMOS cameras equipped with narrow field-of-view lenses (15° by 15°) were directed at magnetic zenith with the north–south base distance of 8.1 km. Here we show the best example that a rapidly pulsating diffuse patch and a streaming discrete arc were observed at the same time with different parallaxes, and the emission altitudes were estimated as 85–95 km and > 100 km, respectively. The estimated emission altitudes are consistent with those estimated in previous studies, and it is suggested that high-speed stereoscopy is useful to directly measure the emission altitudes of various types of rapidly varying aurora. It is also found that variation of emission altitude is gradual (e.g., 10 km increase over 5 s) for pulsating patches and is fast (e.g., 10 km increase within 0.5 s) for streaming arcs.

Smart-RTK: Multi-GNSS kinematic positioning approach on android smart devices with Doppler-smoothed-code filter and constant acceleration model

2019 ◽  
Vol 64 (9) ◽  
pp. 1662-1674 ◽  
Author(s):  
Kaishi Zhang ◽  
Wenhai Jiao ◽  
Liang Wang ◽  
Zishen Li ◽  
Jianwen Li ◽  
...  
Keyword(s):  
Smart Devices ◽  
Constant Acceleration ◽  
Kinematic Positioning ◽  
Acceleration Model

scholarly journals Interplanetary Disturbances Affecting Space Weather

2013 ◽  
Vol 8 (S300) ◽  
pp. 297-306 ◽  
Author(s):  
Robert F. Wimmer-Schweingruber
Keyword(s):  
Space Weather ◽  
Large Scale ◽  
Interplanetary Medium ◽  
Coronal Holes ◽  
Historical Review ◽  
The Sun ◽  
High Speeds ◽  
Large Scale Disturbance ◽  
Mass Ejection ◽  
Very High

AbstractThe Sun somehow accelerates the solar wind, an incessant stream of plasma originating in coronal holes and some, as yet unidentified, regions. Occasionally, coronal, and possibly sub-photospheric structures, conspire to energize a spectacular eruption from the Sun which we call a coronal mass ejection (CME). These can leave the Sun at very high speeds and travel through the interplanetary medium, resulting in a large-scale disturbance of the ambient background plasma. These interplanetary CMEs (ICMEs) can drive shocks which in turn accelerate particles, but also have a distinct intrinsic magnetic structure which is capable of disturbing the Earth's magnetic field and causing significant geomagnetic effects. They also affect other planets, so they can and do contribute to space weather throughout the heliosphere. This paper presents a historical review of early space weather studies, a modern-day example, and discusses space weather throughout the heliosphere.

High resolution multi-viewpoint observations of CME kinematics and dynamics

2020 ◽  
Author(s):  
Niclas Mrotzek ◽  
Volker Bothmer
Keyword(s):  
Extreme Ultraviolet ◽  
Spatial Scales ◽  
Systematic Investigation ◽  
3D Modelling ◽  
Field Of View ◽  
Magnetic Structures ◽  
Weather Forecasts ◽  
Modelling Method ◽  
Temporal And Spatial ◽  
Ambient Solar Wind

&lt;p&gt;Coronal mass ejections (CMEs) are impulsive outbursts of coronal plasma bound in magnetic structures. Their initiation and evolution into the heliosphere covers several orders of magnitude of temporal and spatial scales that can be observed with space-borne extreme ultraviolet imagers, coronagraphs and heliospheric imagers. In this work we present a systematic investigation of the early dynamics of CMEs including their kinematics, orientation and geometrical evolution. For this purpose, a dedicated set of 21 Earth-directed CMEs between July 2011 and November 2012 was selected and analyzed. The CME parametrization is obtained by applying a 3D modelling method, the Graduated Cylindrical Shell (GCS) model, to simultaneous multi-viewpoint observations taken with the SECCHI instrument suite onboard the twin STEREO spacecraft and with the LASCO coronagraphs onboard the SOHO satellite. By using these instruments, the CME dynamics including the kinematics and geometry, are covered in high detail over a wide spatial range. For the majority of events it started in the field of view of EUVI below 2 solar radii and extended into the field of view of HI1 up to 100 solar radii. The results reveal interactions of the CMEs with the ambient solar wind. CME deflections of up to 31&amp;#176; in longitude and 18&amp;#176; in latitude were measured within the first 30 solar radii. Furthermore, evidence of CME oscillations with periods between 29 and 93 minutes were found. The analysis provides important implications for more reliable space weather forecasts and further analysis through the new observations from Parker Solar Probe and Solar Orbiter.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

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