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Malta is being rapidly exposed to developmental activities occurring island and along its coastline, which in turn triggers erosion and flooding in the event of high-intensity rainfall. Most of the rainwater-containing several contaminants from urban and agricultural areas are lost as runoff into the coastal waters, which in turn have adverse environmental and socioeconomic impacts. The extent of soil erosion and runoff can be investigated starting from the watershed basin downhill till coastal waters. This study links the runoff of soil along an ecologically sensitive watershed in Malta with the use of multidisciplinary techniques. These included the estimation of soil erosivity coupled with satellite remote sensing chlorophyll-a (CHLA) and total suspended matter (TSM) in coastal waters adjacent to the mouth of the valley. This represents a novel study for the Maltese islands because it provides a precise map of soil erosion hotspots in the Ramla watershed as high as 30 ton ha−1 yr−1. Using three case studies of past torrential rain episodes, the sedimentation process resulted in a 120% and 133% increase in CHLA and TSM levels, respectively, against background levels. This information is vital for proper risk management of ecologically sensitive watershed basins., peer-reviewed

The scope of this study is to show how the use of airborne LiDAR can in principle be used as an alternative runway control instead of traditional tachymetric surveys. Considering the performances of the most recent LiDAR instrumentation in terms of range, accuracy, point density and rapid acquisition, such instrumentation is bound to offer an interesting opportunity to measure the degree of runway unevenness and identify the current runway surface conditions to highlight problematic areas that could potentially give rise to wet surfaces or the occurrence of water patches or standing water., peer-reviewed

Despite the progress in the international and regional governance efforts at the level of climate change, ocean acidification (OA) remains a global problem with profoundly negative environmental, social, and economical consequences. This requires extensive mitigation and adaptation effective strategies that are hindered by current shortcomings of governance. This multidisciplinary chapter investigates the risks of ocean acidification (OA) for aquaculture and fisheries in the Mediterranean Sea and its sub-basins and the role of regional adaptive governance to tackle the problem. The identified risks are based on the biological sensitivities of the most important aquaculture species and biogenic habitats and their exposure to the current and future predicted (2100) RCP 8.5 conditions. To link OA exposure and biological sensitivity, we produced spatially resolved and depth-related pH and aragonite saturation state exposure maps and overlaid these with the existing aquaculture industry in the coastal waters of the Mediterranean basin to demonstrate potential risk for the aquaculture in the future. We also identified fisheries’ vulnerability through the indirect effects of OA on highly sensitive biogenic habitats that serve as nursery and spawning areas, showing that some of the biogenic habitats are already affected locally under existing OA conditions and will be more severely impacted across the entire Mediterranean basin under 2100 scenarios. This provided a regional vulnerability assessment of OA hotspots, risks and gaps that created the baseline for discussing the importance of adaptive governance and recommendations for future OA mitigation/adaptation strategies. By understanding the risks under future OA scenarios and reinforcing the adaptability of the governance system at the science-policy interface, best informed, “situated” management response capability can be optimised to sustain ecosystem services., peer-reviewed

The link between public policy and climate change has never been as strong as it is now. From the most recent international climate change conferences in Paris, Madrid and Glasgow to emissions regulations, resilience and adaptation, national governments forge public policies aimed at managing the impacts of climate change on primary economic sectors. This is also valid locally where manufacturing, agriculture and energy are just three important sectors that are sensitive to a changing climate. This short article describes the importance of basing our national public policies on factual information that reflects the real impact of a changing climate on our Maltese assets, and not just on an assumed, theoretical one. It aims to make public officials in the public sector aware of the limitations in the local infrastructure that deals with the documentation, archiving, provision and understanding of how physical climate parameters are changing over time and how these can be used by national authorities to redefine public policies accordingly so as to make them Malta specific. Without this knowledge there is a danger that public policies will be less effective or even counterproductive to a select number of our economic sectors, and ultimately to the quality of life of the Maltese people., peer-reviewed

'Cool roofs' and 'evaporative roofs' are modern construction technologies based in part on the known behaviour of 'traditional flat roofs' in the Mediterranean. This paper describes an innovative study of the behaviour of Mediterranean roofs, employing high resolution satellite data, UAV (Unmanned Aerial Vehicle) multispectral technology (visible, near- and thermal-infrared wavelengths) and direct measurements on, and underneath, the roofs of selected buildings in Malta, whilst also comparing to modified and modern flat roofs. This research is determining their real behaviour and advancing the understanding of their performance, whilst promoting their sustainable preservation and maintenance in a changing climate. An interesting outcome of this project has been that satellite (and to a certain extent) UAV technology can remotely identify traditional roofs from other roofs and understand their thermal behaviour. This will be an important tool for policy makers and regulators who need to assess the presence and location of such roofs., peer-reviewed

Photometric observations of asteroid 1466 Mundleria were conducted using telescopes located in New Mexico, Italy and Malta between 2022 Mar 4 and Apr 25. An analysis of these data yielded a rotation period of 89.280+- 0.065h., peer-reviewed

This is the second major contribution by the author following the first edition published in 2011. This publication is a multidecadal report on the state of Malta’s climate based on the data provided by the Meteorological Office situated at Luqa and compiled and analysed by Charles Galdies PhD on behalf of the National Statistics Office. This publication provides an accessible, authoritative and updated analysis of Malta’s climate based on the latest set of climate-quality records, with descriptions of climate conditions and extremes covering the period from 1952 till 2020. In addition, it also explores the associated fluctuations in key climate variables and indices with those observed during the periods 1961-1990 and 1991-2020 over Malta. This second edition presents a new section devoted to future climate projections for Malta as produced by a number of climate forecasting models. These models furnish information to the scientific and decision-making communities and are used by the Intergovernmental Panel on Climate Change (IPCC) of the United Nations to issue its Assessment Reports that are published every six years., peer-reviewed

Synodic rotation periods of six main-belt asteroids were derived from photometric observations obtained from 2021 July 21 through November 2 from three observatories situated in Malta and one from Spain. We provide lightcurve rotation periods for (1713) Banchilon, (2232) Altaj, (2458) Veniakaverin, (6681) Prokopovich, (6787) 1991 PF15, and (18863) 1999 RC191., peer-reviewed

Photometric observations of seven asteroids were acquired from four Maltese observatories in order to derive or update published synodic periods and lightcurve amplitudes of the asteroids: 1461 Jean-Jacques, 2030 Belyaev, 2149 Schwambraniya, 3114 Ercilla, (7357) 1995 UJ7, 12919 Tomjohnson, and (20895) 2000 WU106., peer-reviewed

Observations of the main-belt 3736 Rokoske were conducted over 8 nights between 2022 March 25 and 2022 April 23. Images were collected using three telescopes in the USA, Malta and Italy. 3736 Rokoske has a diameter of 19.5km and an absolute magnitude of 11.15. The phase lightcurve resulted in a rotation period of 17.411+-0.004h and 0.10+-0.02 mag amplitude., peer-reviewed

How a black hole accretes matter and how this process is regulated are fundamental but unsolved questions in astrophysics. In transient black-hole binaries, a lot of mass stored in an accretion disk is suddenly drained to the central black hole because of thermal-viscous instability. This phenomenon is called an outburst and is observable at various wavelengths (Frank et al., 2002). During the outburst, the accretion structure in the vicinity of a black hole shows dramatical transitions from a geometrically-thick hot accretion flow to a geometrically-thin disk, and the transition is observed at X-ray wavelengths (Remillard, McClintock, 2006; Done et al., 2007). However, how that X-ray transition occurs remains a major unsolved problem (Dunn et al., 2008). Here we report extensive optical photometry during the 2018 outburst of ASASSN-18ey (MAXI J1820$+$070), a black-hole binary at a distance of 3.06 kpc (Tucker et al., 2018; Torres et al., 2019) containing a black hole and a donor star of less than one solar mass. We found optical large-amplitude periodic variations similar to superhumps which are well observed in a subclass of white-dwarf binaries (Kato et al., 2009). In addition, the start of the stage transition of the optical variations was observed 5 days earlier than the X-ray transition. This is naturally explained on the basis of our knowledge regarding white dwarf binaries as follows: propagation of the eccentricity inward in the disk makes an increase of the accretion rate in the outer disk, resulting in huge mass accretion to the black hole. Moreover, we provide the dynamical estimate of the binary mass ratio by using the optical periodic variations for the first time in transient black-hole binaries. This paper opens a new window to measure black-hole masses accurately by systematic optical time-series observations which can be performed even by amateur observers., VSOLJ Variable Star Bulletin submitted

This Policy Brief summarizes the key results and recommendations of the Working Group WG Ocean, Climate Change, and Acidification within the COST action CA15217."Ocean Governance for Sustainability – Challenges, Options and the Role of Science" on global and regional management of Ocean Acidification (OA)., GRANTS: COST Action CA15217, Ocean Governance for Sustainability: challenges, options and the role of science". COST European Cooperation in Science and Technology.

Anthropogenic CO2 emission is the main contributor to Ocean Acidification (OA) because the dissolution of this gas in seawater leads to changes in its chemistry resulting in seawater acidity and a lowering of the calcium carbonate saturation state. Apart from impacting severely life at sea, OA acts in conjunction with other environmental drivers connected to climate, such as increased ocean temperature and lower oxygen content, resulting in combined synergistic or combined negative effects to marine life. Despite the increasing scientific certainty on its scale and consequences, and on the need for immediate action, OA stands as a highly overlooked item on the environmental agenda, generally neglected by policymakers at the international, regional and domestic level. Scholars from different disciplines have pointed out the key challenges in dealing with OA in the current fragmented governance landscape, and highlighted that a coordinated governance effort is needed to address OA effectively. At the international level OA is neither adequately integrated in the climate change regime, which is considered a crucial forum for OA, nor in other multilateral environmental treaties, such as the Convention of Biological Diversity, or the Law of the Sea. At the European level, national policies and legislation addressing OA remains scarce and uncoordinated., peer-reviewed

Photometric observations of main-belt asteroid (10422) 1999 AN22 were obtained from May 20 to July 09, 2019, in order to determine its synodic rotation period. Observations were acquired from two observatories in Malta and one from Spain. Through our observational campaign, we present our results obtained for this asteroid that were based on 30 sessions., peer-reviewed

On 2018 August 9, a contribution to the VSNET mailing list suggested that due to certain photometric attributes, NSV 1586 could possibly belong to the Dwarf Nova (DN) class. Hence, the initial classification of this star as a Cepheid variable star was put into question. This prompted the authors to investigate NSV 1586 in detail. The data obtained through our campaign suggest that the original classification of NSV 1586 as a Cepheid star is inconsistent with our findings. We determined the nature of NSV 1586 as a UG-type DN that exhibits peculiar photometric features in its light curve to possibly pertain to the UGZ/IW sub-type variable star classification. However, standstills that are indicative of this class remained undetected. The amplitude of this star was found to be of 2.9 magnitudes in the V-band, with a primary cycle period of 13.9 days. We found the color index during its cyclic permutations can range from an apparent CI of 0.5 to 1.0, corresponding to a temperature change of around 1300 K. Further research is suggested to determine the nature of this star., peer-reviewed

Photometric observations of three main-belt asteroids were made in order to acquire lightcurves. The synodic period and light curve amplitude were found for: 3653 Klimishin 6.783 ± 0.001 h, 0.21 mag; 4748 Tokiwagozen 39.78 ± 0.01 h, 0.42 mag.; 9951 Tyrannosaurus 3.767 ± 0.004 h, 0.21 mag. Asteroid 4748’s lightcurve shows a few interesting features which suggest the opportunity of further observations in order to verify a possible ”tumbling” nature., peer-reviewed

The intermediate polar FO Aquarii experienced its first-reported low-accretion states in 2016, 2017, and 2018. We establish that these low states occurred shortly after the system's white dwarf (WD) began spinning down, after having spent a quarter-century spinning up. FO Aquarii is the only intermediate polar whose period derivative has undergone a sign change, and it has now done so twice. By combining our spin-pulse timings with previous data, we determine that the WD's spin period has varied quasi-sinusoidally since the system's discovery, and an extrapolation predicts that the white dwarf was spinning down during newly discovered low states in photographic plates from 1964, 1965, and 1974. Thus, FO Aquarii's low states appear to occur exclusively during epochs of spindown. Additionally, our time-series photometry of the 2016-18 low states reveals that the mode of accretion is extremely sensitive to the accretion rate; when the system is fainter than V~14.0, the accretion onto the WD is largely stream-fed, but when it is brighter, it is almost exclusively disk-fed. The system's grazing eclipse remained detectable throughout all observations, confirming the uninterrupted presence of a disk-like structure, regardless of the accretion state. Our observations are consistent with theoretical predictions that during the low states, the accretion disk dissipates into a ring of diamagnetic blobs. Finally, a new XMM-Newton observation from 2017 indicates that the system's anomalously soft X-ray spectrum and diminished X-ray luminosity in the wake of the 2016 low state appear to be long-lasting changes compared to pre-2016 observations., peer-reviewed

An observing campaign was conducted among teams at the University of Maryland, College Park, and in Malta to determine the rotation period of 3446 Combes during 2019 March and April. Lightcurve analysis using MPO Canopus of the asteroid was conducted in order to determine its rotation period. Using the eight nights of data, 3446 Combes was found to have a rotation period of 5.6990 ± 0.0005 h and an amplitude of 0.18 mag. The University of Maryland team also observed four additional asteroids that serendipitously appeared in the images: (9410) 1995 BJ, (17780) 1998 FY13, (24491) 2000 YT123, and 28341 Bingaman. These were observed only one night each and only the raw data for them are presented., peer-reviewed

6372 Walker is a main-belt asteroid discovered in 1985 by C.S. Shoemaker at Palomar Observatory and was last observed in May of 2018 (JPL, 2019). It has a diameter of 42.13 km and orbital period of 5.68 yr., peer-reviewed

CCD photometric observations of the outer main-belt asteroid 2670 Chuvashia performed by the author over two nights on 2019 January 28 and 30. The rotation period was found to be 3.846 ± 0.002 h with a lightcurve amplitude of 0.15 ± 0.02 mag., peer-reviewed

Brachytrupes megacephalus (Lefèbvre, 1827) is a relatively large gryllid with predominant but not exclusive distribution across northern Africa, favouring sandy habitats in coastal and Saharan hyper-arid regions. The crepuscular species is also known to occur in certain areas of Europe’s central Mediterranean littoral. The species’ distribution in the Maltese Islands is restricted to fragmented populations on northern coastal sites in Malta and one site in Gozo. The present contribution focuses on the vulnerability of the species’ habitat due to sea level rise and storm surges and estimates that habitat loss on the basis of three modelled inundation scenarios at 5 m, 10 m and 15 m contour heights would be 28.1%, 49.7% and 65.9% respectively. Furthermore, the models developed serve to provide insights for conservation management, specifically through elucidating the potential for linkages that ensure ecological connectivity for subpopulations on elevated terrain., peer-reviewed

Discovery of a new binary star system (UCAC4 735-019611 = USNO-B1.0 1469-0068570 = 2MASS J01561032+5657563) in the Perseus constellation is presented. It was discovered during asteroid photometric work. The shape of the light curve and its characteristics (period of 2.12701 ± 0.00001d, amplitude of V=0.55 mag, initial minimum period epoch HJD 2457363.37784) indicates that the new variable star is an eclipsing binary of Algol (EA) type. We registered this variable star in the International Variable Star Index (VSX) and its AAVSO UID is 000-BLW-283., peer-reviewed

We report the results of our continuing optical and X-ray monitoring of the bright WZ Sge-type dwarf nova TCP J21040470+4631129 (hereafter TCP2104) discovered on July 12, 2019 (for previous reports, see ATel #12947, #13009). Our optical photometric observations are mostly performed using 30-cm class telescopes, while spectroscopic data are obtained with the 2.1-m telescope at the OAN-SPM, the 2.5-m Isaac Newton Telescope on La Palma, and other smaller telescopes., peer-reviewed

New analysis of data we obtained for 3157 Novikov leads to a revised synodic period of 14.930 ± 0.001 h and lightcurve amplitude of 0.27 ± 0.03 mag., peer-reviewed

Collaborative photometric observations of two main-belt asteroids were conducted from five observatories in order to determine their synodic rotation periods. For 3157 Novikov we found a period of 9.952 ± 0.001 h with an amplitude of 0.31 ± 0.04 mag, for 7485 Changchun we found a period of 10.234 ± 0.001 h with an amplitude of 0.39 ± 0.02 mag., peer-reviewed

Photometric observations of three main-belt asteroids were obtained from 2018 April-July from Malta in order to determine their synodic rotation periods. We provide lightcurves for 232 Russia and 1117 Reginita that were obtained from the Spin/Shape Modeling Opportunities list by Warner et al. (2018). The asteroid (11200) 1999 CV121 did not have a referenced period in the LCDB database (Warner et al., 2009)., peer-reviewed

CCD photometric observations of asteroid 1856 Rùžena were taken over a span of 10 nights in April 2018, yielding a lightcurve with a rotation period of 5.960 ± 0.003h and an amplitude of 0.65 mag., peer-reviewed

We present shape and spin axis model for main-belt asteroid 1117 Reginita. The model was achieved with the lightcurve inversion process using combined dense photometric data acquired from nine apparitions between 2003-2018 and sparse data from USNO Flagstaff. Analysis of the resulting data found a sidereal period P = 2.946472 ± 0.000002 hours and two mirrored pole solutions at (λ = 0°, β = 43°) and (λ = 174°, β = 47°) with an uncertainty of ± 5 degrees., peer-reviewed

Lightcurves for three mid-belt asteroids were obtained from Flarestar Observatory (MPC171) and Znith Observatory in 2017 and 2018. These asteroids were selected from the Collaborative Asteroid Lightcurve Link (CALL) website. No reported observations were available to deduce their rotation periods prior to this research., peer-reviewed