The Aditya-L1 is the first space-based solar observatory of the Indian Space Research Organization (ISRO). The spacecraft will carry seven payloads providing uninterrupted observations of the Sun from the first Lagrangian point. Aditya-L1 comprises four remote sensing instruments, viz. a coronagraph observing in visible and infrared, a full disk imager in Near Ultra-Violet (NUV), and two full-sun integrated spectrometers in soft X-ray and hard X-ray. In addition, there are three instruments for in-situ measurements, including a magnetometer, to study the magnetic field variations during energetic events. Aditya-L1 is truly a mission for multi-messenger solar astronomy from space that will provide comprehensive observations of the Sun across the electromagnetic spectrum and in-situ measurements in a broad range of energy, including magnetic field measurements at L1.

Early Warning of Space Weather phenomena is one of the most important products produced by Mexican Space Weather Service (SCiESMEX). The aim is to deliver a verified warning to Mexican National Center for Disaster Prevention (CENAPRED) as well as to general public in near-real time automatically. First, the international pubic warning (or alert) is produced by Space Weather Prediction Center of National Oceanic and Atmospheric Administration, U.S.A. Further, the alert is received by SCiESMEX system, decodified, translated in Spanish and put in the context of local current conditions. The alerts are transformed and validated in agreement to Mexican policies of civil protection and CENAPRED protocols. The automatic system segments the information and delivers the corresponding web- page-alerts, emails, twits, facebook messages and SMS. The latency of the alert is 5 minutes. The code is running since January of 2015 without major interruptions.

A recent study by Cid et al. (2012) showed that full halo coronal mass ejections (CMEs) coming from the limb can disturb the terrestrial environment. Although this result seems to rise some controversies with the well established theories, the fact is that the study encourages the scientific community to perform careful multidisciplinary analysis along the Sun-to-Earth chain to fully understand which are the solar triggers of terrestrial disturbances. This paper aims to clarify some of the polemical issues arisen by that paper.

Practical astronomy is usually taught using optical telescopes or, more rarely, radio telescopes. For a similar cost, complementary studies may be made of astrophysical particles through the use of a modestly sized muon detector. Such a detector records the arrival of cosmic ray particles that have traversed the heliosphere and the rate of muon detections reflects the flux of those particles. That flux is controlled by the day to day properties of the heliosphere which is in a state of constant change as the outflowing solar wind is affected by solar activity. As a consequence, a laboratory muon detector, whose count rate depends on the state of the heliosphere, can be an interesting and useful teaching tool that is complementary to optical or radio studies of the Sun.

The recent minimum was unusually long, and it was not just the case of the “usual story” slowed down. The coronal magnetic field never became completely dipolar as in recent Space Age minima, but rather gradually evolved into an (essentially axisymmetric) global configuration possessing mixed open and closed magnetic structures at many latitudes. In the process, the impact of the solar wind at the Earth went from resembling that from a sequence of rotating “fire-hoses” to what might be expected from a weak, omnidirectional “lawn-sprinkler”. The previous (1996) solar minimum was a more classic dipolar configuration, and was characterized by slow wind of hot origin localized to the heliospheric current sheet, and fast wind of cold origin emitted from polar holes, but filling most of the heliosphere. In contrast, the more recent minimum solar wind possessed a broad range of speeds and source temperatures (although cooler overall than the prior minimum). We discuss possible connections between these observations and the near-radial expansion and small spatial scales characteristic of the recent minimum's porcupine-like magnetic field.

The atmospheric response to the 11-year solar cycle is studied using the fully interactive 3-D coupled chemistry-general circulation model LMDz-REPROBUS with a complete seasonal cycle. We will show results concerning a comparison between two series of 20-year runs, one in maximum of activity and the other in minimum. The stratosphere-troposphere system shows partly significant response to a solar cycle enhancement of UV radiation. We show how the changes in stratospheric ozone, temperature and zonal wind are connected.

Global warming in the troposphere and the decrease of stratospheric ozone concentration has become a major concern to the scientific community. The increase in greenhouse gases and aerosols concentration is believed to be the main cause of this global change in the lower atmosphere and in stratospheric ozone, which is corresponded by a cooling in the middle and upper atmosphere. However, there are natural sources, such as the sun and volcanic eruptions, with the same ability to produce global changes in the atmosphere. The present work will focus on solar variation and its signature in lower and middle atmosphere parameters. The Sun can influence the Earth and its climate through electromagnetic radiation variations and also through changes in the solar wind which causes geomagnetic storms. The effects of both mechanisms over the lower and middle atmosphere and ozone layer will be discussed through an overview of selected papers, which by no means cover this subject that is extremely wide and complex. A fundamental understanding of the atmosphere response to solar variations is required for understanding and interpreting the causes of atmospheric variability. This is an essential focus of climate science, which is seeking to determine the extent to which human activities are altering the planetary energy balance through the emission of greenhouse gases and pollutants.

Analyzing the power spectrum of Total Solar Irradiance (TSI) for the period from 2003 February 25 to 2009 July 6, observed with the Total Irradiance Monitor (TIM) onboard SOlar Radiation and Climate Experiment (SORCE), we found that there are quite a number of periodic variations. The outstanding shortest one is the period of 6.7 days, about one fourth of the period of solar rotation. Checking the solar magnetic field for the same period of time observed with MDI onboard SOHO, we found that there is about 90 degree difference in longitude for the distribution of solar magnetic field. We therefore conclude that both the 90 degree difference in longitude for the distribution of solar magnetic field and the solar rotation are the reason resulting in the periodic variation of 6.7 days for the total solar radiation.

Magnetic helicity (H) is an ideal magnetohydrodynamical (MHD) invariant that quantifies the twist and linkage of magnetic field lines. In magnetofluids with low resistivity, H decays much less than the energy, and it is almost conserved during times shorter than the global diffusion timescale. The extended solar corona (i.e., the heliosphere) is one of the physical scenarios where H is expected to be conserved. The amount of H injected through the photospheric level can be reorganized in the corona, and finally ejected in flux ropes to the interplanetary medium. Thus, coronal mass ejections can appear as magnetic clouds (MCs), which are huge twisted flux tubes that transport large amounts of H through the solar wind. The content of H depends on the global configuration of the structure, then, one of the main difficulties to estimate it from single spacecraft in situ observations (one point - multiple times) is that a single spacecraft can only observe a linear (one dimensional) cut of the MC global structure. Another serious difficulty is the intrinsic mixing between its spatial shape and its time evolution that occurs during the observation period. However, using some simple assumptions supported by observations, the global shape of some MCs can be unveiled, and the associated H and magnetic fluxes (F) can be estimated. Different methods to quantify H and F from the analysis of in situ observations in MCs are presented in this review. Some of these methods consider a MC in expansion and going through possible magnetic reconnections with its environment. We conclude that H seems to be a ‘robust’ MHD quantity in MCs, in the sense that variations of H for a given MC deduced using different methods, are typically lower than changes of H when a different cloud is considered. Quantification of H and F lets us constrain models of coronal formation and ejection of flux ropes to the interplanetary medium, as well as of the dynamical evolution of MCs in the solar wind.

We present results of our study of dependence of planetary geomagnetic activity from geometric factors in geoeffective parameters taking into account orientation of the geomagnetic moment M relative to the vectors of the Interplanetary Magnetic Field (IMF) and electric field of the solar wind E during annual and daily motions of the Earth. We take as our data base space measurements of the IMF and solar wind velocity at the Earth's orbit for 1964-1998 and Kp, Dst indices. Variations of the geometric factors determined by mutual orientation of the vectors E and M can explain 50% of observed variations of Kp and 75% of Dst. We show that geomagnetic activity can reach very high levels of geomagnetic activity Kp = 8 for invariable values of the solar wind electric field by changing only geometric factors.

We study variations of solar activity (sunspot numbers W) and anomaly of global temperature (GT) to detect a connection of their time variations on different time scales (including trends) to understand cause of global warming. We use a method of non-linear spectral analysis that is capable of making a self-consistent selection of trends, non-stationary oscillations and identifiing time intervals of development of non-linear processes (appearence of oscillations of large amplitude) in data. Analysis shows that trends of both spectra contribute main part to the data changes and show correlated increasing of W and GT during the studied interval. Cause of Maunder Minimum and present global warming is regime change (from epoch of damping to epoch of building up) of the powerfull oscillations at T = 1000 yr. from the GT spectrum. Besides, time changes of GT and W has different type of connection in different range of periods T: non-stationary oscillations from the spectra of W and GT at T = 10 yr. and T = 30 yr. vary in opposite phase, at T = 22 yr. vary in phase. The latter means different influence of odd and even 11-yr solar cycles on anomaly of GT (warming and cooling accordingly).

Historical records of the Nile water level provide a unique opportunity to investigate the possibility that solar variability influences the Earth's climate. Particularly important are the annual records of the water level, which are uninterrupted for the years 622–1470 A.D. These records are non-stationary, so that standard spectral analyses cannot adequately characterize them. Here the Empirical Mode Decomposition technique, which is designed to deal with non-stationary, nonlinear time series, becomes useful. It allows the identification of two characteristic time scales in the water level data that can be linked to solar variability: the 88 year period and a time scale of about 200 years. These time scales are also present in the concurrent aurora data. Auroras are driven by coronal mass ejections and the rate of auroras is an excellent proxy for solar variabiliy. Analysis of auroral data contemporaneous with the Nile data shows peaks at 88 years and about 200 years. This suggests a physical link between solar variability and the low-frequency variations of the Nile water level. The link involves the influence of solar variability on the North Annual Mode of atmospheric variability and its North Atlantic and Indian Oceans patterns that affect rainfall over Eastren Equatorial Africa where the Nile originates.

Commission 49 covers research on the solar wind, shocks and particle acceleration, both transient and steady-state, e.g., corotating, structures within the heliosphere, and the termination shock and boundary of the heliosphere. During the last three years there was considerable progress made in studies of solar energetic particles, compositional and other signatures in the heliosphere, solar wind pickup ions, the termination shock, which was finally crossed by a spacecraft, and the boundary between the heliosphere and interstellar medium, and in solar wind modeling and space weather. These topics have been summarized here in five articles, each with extensive references that will guide the reader who wants further details. Observations from the following spacecraft have extensively used during this period: Ulysses, Cassini, Voyager 1 and 2, MESSENGER, ACE, Genesis, SOHO, Wind, and RHESSI.

In recent times, there has been keen interest in understanding Sun-Earth connection events, such as solar flares, CMEs and concomitant magnetic storms. Magnetic storms are the most dramatic and perhaps important component of space weather effects on Earth. Super-intense magnetic storms (defined here as those with Dst $<$ −500 nT, where Dst stands for the disturbance storm time index that measures the strength of the magnetic storm) although relatively rare, have the largest societal and technological relevance. Such storms can cause life-threatening power outages, satellite damage, communication failures and navigational problems. However, the data for such magnetic storms is rather scarce. For example, only one super-intense magnetic storm has been recorded (Dst=−640 nT, March 13, 1989) during the space-age (since 1958), although such storms may have occurred many times in the last 160 years or so when the regular observatory network came into existence. Thus, research on historical geomagnetic storms can help to create a good data base for intense and super-intense magnetic storms. From the application of knowledge of interplanetary and solar causes of storms gained from the spaceage observations applied to the super-intense storm of September 1-2, 1859, it has been possible to deduce that an exceptionally fast (and intense) magnetic cloud was the interplanetary cause of this geomagnetic storm with a Dst −1760 nT, nearly 3 times as large as that of March 13, 1989 super-intense storm. The talk will focus on super-intense storms of September 1-2, 1859, and also discuss the results in the context of some recent intense storms.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

The Geospace Double Star Project (DSP) contains two satellites operating in the near-earth equatorial and polar regions respectively. The tasks of DSP are: (i) to provide high-resolution field, particle and wave measurements in several important near-earth magnetosphere active regions which have not been covered by existing ISTP missions in the geospace, such as the near-earth plasma sheet and its boundary layer, the ring current, the radiation belts, the dayside magnetopause boundary layer, and the polar region; (ii) to investigate the trigger mechanisms of magnetic storms, magnetospheric substorms, and magnetospheric particle storms, as well as the responses of geospace storms to solar activities and interplanetary disturbances; (iii) to set up the models describing the spatial and temporal variations of the near-earth space environment. To complete the mission, there are eight instruments on board the equatorial satellite and the polar satellite, respectively. The orbit of the equatorial satellite with a perigee at 565.5km and an apogee at 78959.9km, and the inclination is 28.17 ; while the orbit of the polar satellite is proposed with a perigee at 700km and an apogee at 40000km, as well as an inclination about 90. The equatorial satellite has been launched successfully in December 2003. Now the equatorial satellite (TC-1) and instruments operate normally. Payloads have provided good quality of data of fields and particles. Already very good conjunction in the dayside magnetopause and magnetotail with Cluster, CME effects could be investigated. The first results of data analysis have already shown great interesting. The polar (TC-2) satellite has been launched successfully in July 2004. Now the satellite operates normally. The commissioning of the payload has started since the end of July 2004 and will be finished in the middle of Sep.2004. The instrument has been normally operation and downlink the data.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Observations of the low solar corona, in particular in the EUV, are an effective means of identifying the solar sources of coronal mass ejections (CMEs). SOHO/EIT, with its continuous 24 hours per day coverage, is well suited to perform this task. Source regions and start times of frontside full and partial halo CMEs (that may be geoeffective) can thus be determined. The most frequent EUV signatures of CMEs are coronal dimmings. EIT waves, eruptive filaments and post-eruption arcades are also reliable signatures. Frontside halo CMEs with source regions close to the solar disc center have the strongest chance to hit the Earth. The inspection of the EIT data together with photospheric magnetograms may give an idea about the ejected interplanetary flux rope magnetic field and, in particular, about the presence or absence of southward (geoeffective) field. If a source region is situated close to the solar limb, the corresponding CME also may be geoeffective, as the CME-driven shocks have large angular extent. In this case the storm can be produced by the sheath plasma behind the shock, provided it contains strong enough southward interplanetary magnetic field. Some implications for the operational space weather forecast are discussed. EIT and LASCO are capable to identify the solar sources of the most of geomagnetic storms. In some cases, however, the identification is uncertain, so the observations by the future STEREO mission will be needed for the investigation of similar events.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html