Platelet endothelial aggregation receptor 1 (PEAR1) triggers platelet aggregation and is expressed in platelets and endothelial cells. Genome-wide association studies (GWAS) showed an association ...between platelet function and single-nucleotide polymorphisms (SNPs) in
.
In 582 consecutive patients with stable coronary artery disease (CAD) or acute coronary syndrome (ACS) scheduled for PCI and treated with ASA and Clopidogrel, Prasugrel, or Ticagrelor, SNP analysis for rs12566888, rs2768759, rs41273215, rs3737224, and rs822442 was performed. During a follow-up period of 365 days after initial PCI, all patients were tracked for a primary endpoint, defined as a combined endpoint consisting of either time to death, myocardial infarction (MI) or ischemic stroke. All cause mortality, MI and ischemic stroke were defined as secondary endpoints.
Multivariable Cox model analysis for the primary endpoint revealed a significantly increased risk in homozygous
rs2768759 minor allele carriers (hazard ratio, 3.16; 95% confidence interval, 1.4-7.13,
= 0.006). Moreover,
rs12566888 minor allele carriers also showed an increased risk in all patients (hazard ratio, 1.69; 95% confidence interval, 0.87-3.27,
= 0.122), which was marginally significant in male patients (hazard ratio, 2.12; 95% confidence interval, 1.02-4.43,
= 0.045;
= 425).
To the best of our knowledge, this is the first study showing that distinct genetic variants of
are associated with cardiovascular prognosis in high risk patients undergoing PCI and treated with dual anti platelet therapy.
We present a major update to the 3D coronal rope ejection (3DCORE) technique for modeling coronal mass ejection flux ropes in conjunction with an approximate Bayesian computation (ABC) algorithm that ...is used for fitting the model to in situ magnetic field measurements. The model assumes an empirically motivated torus-like flux rope structure that expands self-similarly within the heliosphere, is influenced by a simplified interaction with the solar wind environment, and carries along an embedded analytical magnetic field. The improved 3DCORE implementation allows us to generate extremely large ensemble simulations that we then use to find global best-fit model parameters using an ABC sequential Monte Carlo algorithm. The usage of this algorithm, under some basic assumptions on the uncertainty of the magnetic field measurements, allows us to furthermore generate estimates on the uncertainty of model parameters using only a single in situ observation. We apply our model to synthetically generated measurements to prove the validity of our implementation for the fitting procedure. We also present a brief analysis, within the scope of our model, of an event captured by the Parker Solar Probe shortly after its first flyby of the Sun on 2018 November 12 at 0.25 au. The presented toolset is also easily extendable to the analysis of events captured by multiple spacecraft and will therefore facilitate future multipoint studies.
The Parker Solar Probe (PSP) and Solar Orbiter missions are designed to make groundbreaking observations of the Sun and interplanetary space within this decade. We show that a particularly ...interesting in situ observation of an interplanetary coronal mass ejection (ICME) by PSP may arise during close solar flybys (<0.1 au). During these times, the same magnetic flux rope inside an ICME could be observed in situ by PSP twice, by impacting its frontal part as well as its leg. Investigating the odds of this situation, we forecast the ICME rate in solar cycle 25 based on two models for the sunspot number (SSN): (1) the forecast of an expert panel in 2019 (maximum SSN = 115), and (2) a prediction by McIntosh et al. (2020, maximum SSN = 232). We link the SSN to the observed ICME rates in solar cycles 23 and 24 with the Richardson and Cane list and our own ICME catalog, and calculate that between one and seven ICMEs will be observed by PSP at heliocentric distances <0.1 au until 2025, including 1 uncertainties. We then model the potential flux rope signatures of such a double-crossing event with the semiempirical 3DCORE flux rope model, showing a telltale elevation of the radial magnetic field component BR, and a sign reversal in the component BN normal to the solar equator compared to field rotation in the first encounter. This holds considerable promise to determine the structure of CMEs close to their origin in the solar corona.
Abstract
We report the result of the first search for multipoint in situ and imaging observations of interplanetary coronal mass ejections (ICMEs) starting with the first Solar Orbiter (SolO) data in ...2020 April–2021 April. A data exploration analysis is performed including visualizations of the magnetic-field and plasma observations made by the five spacecraft SolO, BepiColombo, Parker Solar Probe (PSP), Wind, and STEREO-A, in connection with coronagraph and heliospheric imaging observations from STEREO-A/SECCHI and SOHO/LASCO. We identify ICME events that could be unambiguously followed with the STEREO-A heliospheric imagers during their interplanetary propagation to their impact at the aforementioned spacecraft and look for events where the same ICME is seen in situ by widely separated spacecraft. We highlight two events: (1) a small streamer blowout CME on 2020 June 23 observed with a triple lineup by PSP, BepiColombo and Wind, guided by imaging with STEREO-A, and (2) the first fast CME of solar cycle 25 (≈1600 km s
−1
) on 2020 November 29 observed in situ by PSP and STEREO-A. These results are useful for modeling the magnetic structure of ICMEs and the interplanetary evolution and global shape of their flux ropes and shocks, and for studying the propagation of solar energetic particles. The combined data from these missions are already turning out to be a treasure trove for space-weather research and are expected to become even more valuable with an increasing number of ICME events expected during the rise and maximum of solar cycle 25.
Aims.
We present observations of the first coronal mass ejection (CME) observed by the Solar Orbiter spacecraft on April 19, 2020 and the associated Forbush decrease (FD) measured by the High Energy ...Telescope (HET). This CME is a multi-spacecraft event that was also seen near Earth the following day.
Methods.
We highlight the capabilities of the HET for observing small short-term variations of the galactic cosmic ray count rate using its single detector counters. We applied the analytical ForbMod model to the FD measurements to reproduce the Forbush decrease at both locations. Input parameters for the model were derived from both in situ and remote-sensing observations of the CME.
Results.
The very slow (∼350 km s
−1
) stealth CME caused an FD with an amplitude of 3% in the low-energy cosmic ray measurements at HET and 2% in a comparable channel of the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) on board the Lunar Reconnaissance Orbiter, as well as a 1% decrease in neutron monitor measurements. Significant differences are observed in the expansion behavior of the CME at different locations, which may be related to influence of the following high speed solar wind stream. Under certain assumptions, ForbMod is able to reproduce the observed FDs in low-energy cosmic ray measurements from HET as well as CRaTER, however, with the same input parameters, the results do not agree with the FD amplitudes at higher energies measured by neutron monitors on Earth. We study these discrepancies and provide possible explanations.
Conclusions.
This study highlights the notion that the novel measurements of Solar Orbiter can be coordinated with observations from other spacecraft to improve our understanding of space weather in the inner heliosphere. Multi-spacecraft observations combined with data-based modeling are also essential for understanding the propagation and evolution of CMEs, in addition to their space weather impacts.
In this study, we evaluate a coronal mass ejection (CME) arrival prediction tool that utilizes the wide‐angle observations made by STEREO's heliospheric imagers (HI). The unsurpassable advantage of ...these imagers is the possibility to observe the evolution and propagation of a CME from close to the Sun out to 1 AU and beyond. We believe that by exploiting this capability, instead of relying on coronagraph observations only, it is possible to improve today's CME arrival time predictions. The ELlipse Evolution model based on HI observations (ELEvoHI) assumes that the CME frontal shape within the ecliptic plane is an ellipse and allows the CME to adjust to the ambient solar wind speed; that is, it is drag based. ELEvoHI is used to perform ensemble simulations by varying the CME frontal shape within given boundary conditions that are consistent with the observations made by HI. In this work, we evaluate different setups of the model by performing hindcasts for 15 well‐defined isolated CMEs that occurred when STEREO was near L4/5, between the end of 2008 and the beginning of 2011. In this way, we find a mean absolute error of between 6.2 ± 7.9 and 9.9 ± 13 hr depending on the model setup used. ELEvoHI is specified for using data from future space weather missions carrying HIs located at L5 or L1. It can also be used with near‐real‐time STEREO‐A HI beacon data to provide CME arrival predictions during the next ∼7 years when STEREO‐A is observing the Sun‐Earth space.
Key Points
CME prediction tool ELEvoHI is ready to be used in real time, based on STEREO‐A/HI beacon data
Different model setups and inputs lead to large differences of the prediction accuracies
Accurate modeling of the ambient solar wind is of particular importance to improve CME predictions
The evolution and propagation of coronal mass ejections (CMEs) in interplanetary space is still not well understood. As a consequence, accurate arrival time and arrival speed forecasts are an ...unsolved problem in space weather research. In this study, we present the ELlipse Evolution model based on HI observations (ELEvoHI) and introduce a deformable front to this model. ELEvoHI relies on heliospheric imagers (HI) observations to obtain the kinematics of a CME. With the newly developed deformable front, the model is able to react to the ambient solar wind conditions during the entire propagation and along the whole front of the CME. To get an estimate of the ambient solar wind conditions, we make use of three different models: Heliospheric Upwind eXtrapolation model (HUX), Heliospheric Upwind eXtrapolation with time dependence model (HUXt), and EUropean Heliospheric FORecasting Information Asset (EUHFORIA). We test the deformable front on a CME first observed in STEREO‐A/HI on February 3, 2010 14:49 UT. For this case study, the deformable front provides better estimates of the arrival time and arrival speed than the original version of ELEvoHI using an elliptical front. The new implementation enables us to study the parameters influencing the propagation of the CME not only for the apex, but for the entire front. The evolution of the CME front, especially at the flanks, is highly dependent on the ambient solar wind model used. An additional advantage of the new implementation is given by the possibility to provide estimates of the CME mass.
Plain Language Summary
Coronal mass ejections (CMEs) are large explosions of plasma and magnetic field erupting from the solar surface. When directed toward Earth, they cause negative effects in near Earth environment and damage human technology so it is important to forecast the arrival time and arrival speed of CMEs. We present an updated version of an already existing CME arrival model that integrates the drag force between a CME and the ambient solar wind and assumes an elliptical shape of the CME front. The newly developed CME arrival prediction model is able to adjust its front to the conditions in the ambient solar wind. We test this approach using different ambient solar wind models for a single CME, and find that the estimated arrival times and arrival speeds are closer to the actual arrivals at Earth using a deformable front. We also see that a more structured ambient solar wind leads to more deformation of the CME front.
Key Points
The implementation of a deformable front based on ELlipse Evolution model based on heliospheric imagers for three different ambient solar winds models is presented
The parameters influencing the propagation of the coronal mass ejection are studied in detail
For all the three ambient solar wind models the deformable front provides better model results than the elliptical front
Aims. We present observations of the first coronal mass ejection (CME) observed by the Solar Orbiter spacecraft on April 19, 2020 and the associated Forbush decrease (FD) measured by the High Energy ...Telescope (HET). This CME is a multi-spacecraft event that was also seen near Earth the following day. Methods. We highlight the capabilities of the HET for observing small short-term variations of the galactic cosmic ray count rate using its single detector counters. We applied the analytical ForbMod model to the FD measurements to reproduce the Forbush decrease at both locations. Input parameters for the model were derived from both in situ and remote-sensing observations of the CME. Results. The very slow (∼350 km s−1) stealth CME caused an FD with an amplitude of 3% in the low-energy cosmic ray measurements at HET and 2% in a comparable channel of the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) on board the Lunar Reconnaissance Orbiter, as well as a 1% decrease in neutron monitor measurements. Significant differences are observed in the expansion behavior of the CME at different locations, which may be related to influence of the following high speed solar wind stream. Under certain assumptions, ForbMod is able to reproduce the observed FDs in low-energy cosmic ray measurements from HET as well as CRaTER, however, with the same input parameters, the results do not agree with the FD amplitudes at higher energies measured by neutron monitors on Earth. We study these discrepancies and provide possible explanations. Conclusions. This study highlights the notion that the novel measurements of Solar Orbiter can be coordinated with observations from other spacecraft to improve our understanding of space weather in the inner heliosphere. Multi-spacecraft observations combined with data-based modeling are also essential for understanding the propagation and evolution of CMEs, in addition to their space weather impacts.
Accurate forecasting of the arrival time and arrival speed of coronal mass ejections (CMEs) is an unsolved problem in space weather research. In this study, a comparison of the predicted arrival ...times and speeds for each CME based, independently, on the inputs from the two STEREO vantage points is carried out. We perform hindcasts using ELlipse Evolution model based on Heliospheric Imager observations (ELEvoHI) ensemble modeling. An estimate of the ambient solar wind conditions is obtained by the Wang‐Sheeley‐Arge/Heliospheric Upwind eXtrapolation (WSA/HUX) model combination that serves as input to ELEvoHI. We carefully select 12 CMEs between February 2010 and July 2012 that show clear signatures in both STEREO‐A and STEREO‐B HI time‐elongation maps, that propagate close to the ecliptic plane, and that have corresponding in situ signatures at Earth. We find a mean arrival time difference of 6.5 h between predictions from the two different viewpoints, which can reach up to 9.5 h for individual CMEs, while the mean arrival speed difference is 63 km s−1. An ambient solar wind with a large speed variance leads to larger differences in the STEREO‐A and STEREO‐B CME arrival time predictions (cc = 0.92). Additionally, we compare the predicted arrivals, from both spacecraft, to the actual in situ arrivals at Earth and find a mean absolute error of 7.5 ± 9.5 h for the arrival time and 87 ± 111 km s−1 for the arrival speed. There is no tendency for one spacecraft to provide more accurate arrival predictions than the other.
Key Points
A comparison of CME arrival time and speed predictions from two vantage points was carried out using ELEvoHI
A highly structured ambient solar wind flow leads to larger arrival time differences between STA and STB predictions
The assumption of a rigid CME front in ELEvoHI and other HI‐based methods is most probably too simplistic
Being able to accurately predict the arrival of coronal mass ejections (CMEs) at Earth has been a long‐standing problem in space weather research and operations. In this study, we use the ELlipse ...Evolution model based on Heliospheric Imager (ELEvoHI) to predict the arrival time and speed of 10 CME events that were observed by HI on the STEREO‐A spacecraft between 2010 and 2020. Additionally, we introduce a Python tool for downloading and preparing STEREO‐HI data, as well as tracking CMEs. In contrast to most previous studies, we use not only science data, which have a relatively high spatial and temporal resolution, but also lower‐quality beacon data, which are—in contrast to science data—provided in real‐time by the STEREO‐A spacecraft. We do not use data from the STEREO‐B spacecraft. We get a mean absolute error of 8.81 ± 3.18 hr/59 ± 31 km s−1 for arrival time/speed predictions using science data and 11.36 ± 8.69 hr/106 ± 61 km s−1 for beacon data. We find that using science data generally leads to more accurate predictions, but using beacon data with the ELEvoHI model is certainly a viable choice in the absence of higher resolution real‐time data. We propose that these differences could be minimized if not eliminated altogether if higher quality real‐time data were available, either by enhancing the quality of the already available data or coming from a new mission carrying a HI instrument on‐board.
Plain Language Summary
Coronal mass ejections (CMEs) are large ejections of plasma and the accompanying magnetic field caused by magnetic activity on the Sun. If CMEs reach Earth, they interact with the planetary magnetic field. In doing so, CMEs can cause disturbances to power grids and other electrical infrastructure on our planet, inhibit radio transmissions and damage satellites, which is why it is important to have an accurate way of predicting the arrival of the phenomena. Our model uses data provided by the HI cameras on the STEREO spacecraft. These data are available in a lower quality in real‐time, that is, within a latency of about 5 min within being received at the ground station, or in a higher quality with a delay of around 3 days. Using real‐time data is important if we want to be able to predict the arrival of CMEs in a timely manner. In this study, we show that we can use the lower‐quality real‐time STEREO‐HI data to make accurate predictions of the arrival time of CMEs.
Key Points
The viability of using the Ellipse Evolution Model based on Heliospheric Imager (ELEvoHI) model with lower‐quality real‐time data was studied
The impact of variations between time‐elongation profiles on CME predictions caused by human error was evaluated
We find that using real‐time data with ELEvoHI is possible, but coronal mass ejection prediction benefits significantly from improved data quality
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