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The Solar EUV Monitor (SEM) onboard SOHO has measured absolute extreme ultraviolet (EUV) and soft X-ray solar irradiance nearly continuously since January 1996. The EUV Variability Experiment (EVE) on SDO, in operation since April of 2010, measures solar irradiance in a wide spectral range that encompasses the band passes (26 – 34 nm and 0.1 – 50 nm) measured by SOHO/SEM. However, throughout the mission overlap, irradiance values from these two instruments have differed by more than the combined stated uncertainties of the measurements. In an effort to identify the sources of these differences and eliminate them, we investigate in this work the effect of reprocessing the SEM data using a more accurate SEM response function (obtained from synchrotron measurements with a SEM sounding-rocket clone instrument taken after SOHO was already in orbit) and time-dependent, measured solar spectral distributions – i.e ., solar reference spectra that were unavailable prior to the launch of the SDO. We find that recalculating the SEM data with these improved parameters reduces mean differences with the EVE measurements from about 20 % to less than 5 % in the 26 – 34 nm band, and from about 35 % to about 15 % for irradiances in the 0.1 – 7 nm band extracted from the SEM 0.1 – 50 nm channel.

We present the lessons learned about the degradation observed in several space solar missions, based on contributions at the Workshop about On-Orbit Degradation of Solar and Space Weather Instruments that took place at the Solar Terrestrial Centre of Excellence (Royal Observatory of Belgium) in Brussels on 3 May 2012. The aim of this workshop was to open discussions related to the degradation observed in Sun-observing instruments exposed to the effects of the space environment. This article summarizes the various lessons learned and offers recommendations to reduce or correct expected degradation with the goal of increasing the useful lifespan of future and ongoing space missions.

The Solar Aspect Monitor (SAM) is a pinhole camera on the Extreme-ultraviolet Variability Experiment (EVE) aboard the Solar Dynamics Observatory (SDO). SAM projects the solar disk onto the CCD through a metallic filter designed to allow only solar photons shortward of 7 nm to pass. Contamination from energetic particles and out-of-band irradiance is, however, significant in the SAM observations. We present a technique for isolating the 0.01--7 nm integrated irradiance from the SAM signal to produce the first results of broadband irradiance for the time period from May 2010 to May 2014. The results of this analysis agree with a similar data product from EVE's EUV SpectroPhotometer (ESP) to within 25%. We compare our results with measurements from the Student Nitric Oxide Explorer (SNOE) Solar X-ray Photometer (SXP) and the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) Solar EUV Experiment (SEE) at similar levels of solar activity. We show that the full-disk SAM broadband results compare well to the other measurements of the 0.01--7 nm irradiance. We also explore SAM's capability toward resolving spatial contribution from regions of solar disk in irradiance and demonstrate this feature with a case study of several strong flares that erupted from active regions on March 11, 2011.

We present the lessons learned about the degradation observed in several space solar missions, based on contributions at the Workshop about On-Orbit Degradation of Solar and Space Weather Instruments that took place at the Solar Terrestrial Centre of Excellence (Royal Observatory of Belgium) in Brussels on 3 May 2012. The aim of this workshop was to open discussions related to the degradation observed in Sun-observing instruments exposed to the effects of the space environment. This article summarizes the various lessons learned and offers recommendations to reduce or correct expected degradation with the goal of increasing the useful lifespan of future and ongoing space missions.

The solar irradiance in the Extreme Ultraviolet (EUV) spectral bands has been observed with a 15 sec cadence by the SOHO Solar EUV Monitor (SEM) since 1995. During remarkably intense solar flares the SEM EUV measurements are saturated in the central (zero) order channel (0.1 -- 50.0 nm) by the flare soft X-ray and EUV flux. The first order EUV channel (26 -- 34 nm) is not saturated by the flare flux because of its limited bandwidth, but it is sensitive to the arrival of Solar Energetic Particles (SEP). While both channels detect nearly equal SEP fluxes, their contributions to the count rate is sensibly negligible in the zero order channel but must be accounted for and removed from the first channel count rate. SEP contribution to the measured SEM signals usually follows the EUV peak for the gradual solar flare events. Correcting the extreme solar flare SEM EUV measurements may reveal currently unclear relations between the flare magnitude, dynamics observed in different EUV spectral bands, and the measured Earth atmosphere response. A simple and effective correction technique based on analysis of SEM count-rate profiles, GOES X-ray, and GOES proton data has been developed and used for correcting EUV measurements for the five extreme solar flare events of July 14, 2000, October 28, November 2, November 4, 2003, and January 20, 2005. Although none of the 2000 and 2003 flare peaks were contaminated by the presence of SEPs, the January 20, 2005 SEPs were unusually prompt and contaminated the peak. The estimated accuracy of the correction is about 7.5% for large X-class events.

An indirect proton flux measuring tool based on discrimination of the energy deposited by protons in 128 x 128 pixel EIT CCD areas outside the solar disk images is presented. Single pixel intensity events are converted into proton incident energy flux using modeled energy deposition curves for angles of incidence 60 deg in four EIT spatial areas with different proton stopping power. The extracted proton flux is corrected for both the loss of one-pixel events in the range of angles of incidence as well as for the contribution to the single pixel events resulting from scattered middle-energy protons (low-energy or high-energy particles are stopped by the EIT components or pass through them, accordingly). A simple geometrical approach was found and applied to correct for a non-unique relation between the proton-associated CCD output signal and the incident proton energy. With this geometrical approximation four unique proton incident energy ranges were determined as 45--49, 145--154, 297--335, and 390--440 MeV. The indirect proton flux measuring tool has been tested by comparing Solar Energetic Particles (SEP) flux temporal profiles extracted from the EIT CCD frames and downloaded from the GOES database for the Bastille Day (BD) of 2000 July 14 and the more recent 2005 January 20 events. The SEP flux temporal profiles and proton spectra extracted from the EIT in the relatively narrow energy ranges between 45 and 440 MeV reported here are consistent with the related GOES profiles. The four additional EIT extracted ranges provide higher energy resolution of the SEP data.

Solar activity during 2007–2009 was very low, and during this protracted solar minimum period, the terrestrial thermosphere was cooler and lower in density than expected. Measurements from instruments on the SOHO and TIMED spacecraft, and by suborbital rocket flights, indicate that solar extreme‐ultraviolet irradiance levels were lower than they were during the previous solar minimum. Analysis of atmospheric drag on satellite orbits indicate that the thermosphere was lower in density, and therefore cooler, and than at any time since the beginning of the space age. However, secular change due to increasing levels of carbon dioxide and other greenhouse gases, which cool the upper atmosphere, also plays a role in thermospheric climate. Simulations by the NCAR Thermosphere‐Ionosphere‐Electrodynamics General Circulation Model are compared to thermospheric density measurements, yielding evidence that the primary cause of the low thermospheric density was the unusually low level of solar extreme‐ultraviolet irradiance.

Objective. To seek relationships between results from functional brain imaging, immunological indicators, and laboratory markers of neuroinflammation in schizophrenia taking account of cognitive impairments in patients in relation to the potential for creating an interdisciplinary approach to the diagnosis, treatment, and prognostication of disease. Materials and methods. A total of 25 patients with schizophrenia (study group) and 13 healthy subjects (control group) took part in the study. Patients’ mental health was evaluated with a variety of psychometric scales. The main measures of humoral immunity, levels of inflammation markers, key cytokines, and growth factor VEGF were determined by ELISA and patients underwent brain MRI. All tractographic data were loaded into a connectome database to study the effects of the concentrations of immunological markers and the severity of cognitive impairments. Results and conclusions. A relationship was found between immunological parameters and the coefficient of quantitative anisotropy in the corpus callosum in schizophrenia. The results also provide evidence of the possible value of measures of activation of humoral immune responses and systemic inflammation as markers of neurophysiological changes and cognitive dysfunction in schizophrenia.

Objectives. To study the relationship between measures of immunity and systemic inflammation and structural magnetic resonance imaging (MRI) indicators in patients with pre-dementia cognitive disorders (pre CI) during neurocognitive rehabilitation with the aim of identifying candidate markers for the efficacy of this rehabilitation. Materials and methods. The study group consisted of 49 patients with preMCI with memory impairments; patients were aged 60 years and older and underwent five-week neurorehabilitation courses. The control group consisted of 19 volunteers of similar age without cognitive disorders or immune-inflammatory disorders. Measures of cellular and humoral immunity and inflammatory markers were determined and structural MRI was performed. Results. preMCI was found to be associated with an elevated content of activated natural killers (NK cells) (0.63 ± 0.12% versus 0.22 ± 0.07% in the control group, p = 2.2 10–7). Immunoglobulin G (IgG) levels of <12.5 g/liter in patients with preMCI and scores of <22 on the Montreal Cognitive Assessment (MoCA) were associated with decreases in the volume of the right nucleus accumbens (376 ± 35 mm3 with IgG <12.5 g/liter (p = 0.0013), 429 ± 40 mm3 at IgG >12.5 g/liter, and 480 ± 44 mm3 in the control group), as well as the thickness and volume of some other cortical areas. A logistic regression model (R2 = 0.57; p < 1 10–5; standard error of estimate 2.93) was built, including immunoglobulin G, NK cells, CD8+ NK cell levels, and the volume of the right amygdala, which predicted MoCA scores six months after rehabilitation courses. Conclusions. These studies provide the first demonstration that immune parameters in combination with socio-demographic data and brain morphometric indexes are highly significant as potential prognostic markers reflecting the response to neurorehabilitation.