International Centre For Theoretical Physics Research Articles

Influence of future climate scenarios using CMIP 5 data on malaria transmission in India

BackgroundVector-borne diseases, such as malaria, pose a significant global threat, and climatological factors greatly influence their intensity. Tropical countries, like India, are particularly vulnerable to such diseases, making accurate estimation of malaria risk crucial.MethodsThis study utilized the well-known Vector-borne Disease Community Model, VECTRI, developed by the International Centre for Theoretical Physics in Trieste. The model was implemented to estimate malaria’s Entomological Inoculation Rate (EIR). Future climatic prediction datasets, including CMIP 5 and population data sets, were used as inputs for the analysis. Three RCP scenarios are considered (Representative Concentration Pathways are climate change scenarios that project radiative forcing to 2100 due to future greenhouse gas concentrations). The projections covered the period from 1 Jan, 2020, to 31 Dec, 2029.ResultsThe estimated mean EIR for the years 2020–2029 ranged, and a significant decline in malaria risk was observed with all RCP 2.6, 4.5, and 8.5 scenarios. Each year 0.3 to 2.6 [min–max] EIR/person/day decline is observed with a strong decline in man rainfall ranging from 5 to 17 [min–max] mm/year and associated high temperatures ranging from 0.03 to 0.06 [min–max] °C/year. During the post-monsoon period, August to November were identified as highly prone to malaria transmission. Spatial analysis revealed that the east coast of India faced a higher vulnerability to malaria risk, which kept increasing through RCP scenarios. Thus, it is essential to exercise caution, especially in areas with heavy rainfall.ConclusionThis research provides valuable insights for policy-makers, highlighting the need to implement future strategies to mitigate malaria risk effectively. By utilizing these findings, appropriate measures can be taken to combat the threat posed by malaria and protect public health.

A tribute to Abdus Salam

Claudia de Rham and Ian Walmsley pay tribute to the contributions of the Nobel-prize winning particle theorist Abdus Salam, who founded the International Centre for Theoretical Physics (ICTP) in Trieste, Italy, 60 years ago. They speak to Matin Durrani.

The effect of explicit convection on simulated malaria transmission across Africa.

Malaria transmission across sub-Saharan Africa is sensitive to rainfall and temperature. Whilst different malaria modelling techniques and climate simulations have been used to predict malaria transmission risk, most of these studies use coarse-resolution climate models. In these models convection, atmospheric vertical motion driven by instability gradients and responsible for heavy rainfall, is parameterised. Over the past decade enhanced computational capabilities have enabled the simulation of high-resolution continental-scale climates with an explicit representation of convection. In this study we use two malaria models, the Liverpool Malaria Model (LMM) and Vector-Borne Disease Community Model of the International Centre for Theoretical Physics (VECTRI), to investigate the effect of explicitly representing convection on simulated malaria transmission. The concluded impact of explicitly representing convection on simulated malaria transmission depends on the chosen malaria model and local climatic conditions. For instance, in the East African highlands, cooler temperatures when explicitly representing convection decreases LMM-predicted malaria transmission risk by approximately 55%, but has a negligible effect in VECTRI simulations. Even though explicitly representing convection improves rainfall characteristics, concluding that explicit convection improves simulated malaria transmission depends on the chosen metric and malaria model. For example, whilst we conclude improvements of 45% and 23% in root mean squared differences of the annual-mean reproduction number and entomological inoculation rate for VECTRI and the LMM respectively, bias-correcting mean climate conditions minimises these improvements. The projected impact of anthropogenic climate change on malaria incidence is also sensitive to the chosen malaria model and representation of convection. The LMM is relatively insensitive to future changes in precipitation intensity, whilst VECTRI predicts increased risk across the Sahel due to enhanced rainfall. We postulate that VECTRI's enhanced sensitivity to precipitation changes compared to the LMM is due to the inclusion of surface hydrology. Future research should continue assessing the effect of high-resolution climate modelling in impact-based forecasting.

Enhancing Understanding of the Impact of Climate Change on Malaria in West Africa Using the Vector-Borne Disease Community Model of the International Center for Theoretical Physics (VECTRI) and the Bias-Corrected Phase 6 Coupled Model Intercomparison Project Data (CMIP6)

In sub-Saharan Africa, temperatures are generally conducive to malaria transmission, and rainfall provides mosquitoes with optimal breeding conditions. The objective of this study is to assess the impact of future climate change on malaria transmission in West Africa using community-based vector-borne disease models, TRIeste (VECTRI). This VECTRI model, based on bias-corrected data from the Phase 6 Coupled Model Intercomparison Project (CMIP6), was used to simulate malaria parameters, such as the entomological inoculation rate (EIR). Due to the lack of data on confirmed malaria cases throughout West Africa, we first validated the forced VECTRI model with CMIP6 data in Senegal. This comparative study between observed malaria data from the National Malaria Control Program in Senegal (Programme National de Lutte contre le Paludisme, PNLP, PNLP) and malaria simulation data with the VECTRI (EIR) model has shown the ability of the biological model to simulate malaria transmission in Senegal. We then used the VECTRI model to reproduce the historical characteristics of malaria in West Africa and quantify the projected changes with two Shared Socio-economic Pathways (SSPs). The method adopted consists of first studying the climate in West Africa for a historical period (1950–2014), then evaluating the performance of VECTRI to simulate malaria over the same period (1950–2014), and finally studying the impact of projected climate change on malaria in a future period (2015–2100) according to the ssp245 ssp585 scenario. The results showed that low-latitude (southern) regions with abundant rainfall are the areas most affected by malaria transmission. Two transmission peaks are observed in June and October, with a period of high transmission extending from May to November. In contrast to regions with high latitudes in the north, semi-arid zones experience a relatively brief transmission period that occurs between August, September, and October, with the peak observed in September. Regarding projections based on the ssp585 scenario, the results indicate that, in general, malaria prevalence will gradually decrease in West Africa in the distant future. But the period of high transmission will tend to expand in the future. In addition, the shift of malaria prevalence from already affected areas to more suitable areas due to climate change is observed. Similar results were also observed with the ssp245 scenario regarding the projection of malaria prevalence. In contrast, the ssp245 scenario predicts an increase in malaria prevalence in the distant future, while the ssp585 scenario predicts a decrease. These findings are valuable for decision makers in developing public health initiatives in West Africa to mitigate the impact of this disease in the region in the context of climate change.

Will Warming Climate Affect the Characteristics of Summer Monsoon Rainfall and Associated Extremes Over the Gangetic Plains in India?

AbstractThe Indo‐Gangetic Plain (IGP) bears great agricultural importance and contributes to a major share of national GDP of India. In present study, a location‐specific comprehensive analysis of rainfall extremes over IGP, using second generation CORDEX‐CORE simulations in the present and future scenarios (under high emission RCP8.5 scenario) have been performed. Here, the high‐resolution CORDEX‐CORE simulations with International Centre for Theoretical Physics's regional climate model (RegCM4.7) have been considered for the detailed rainfall characteristics assessment. Twelve thresholds‐based climate indices have been analyzed to investigate the characteristics of rainfall extremes during three‐time slices: 1986–2005 (historical), 2041–2060 (near future) and 2080–2099 (far future). The RegCM4 projections suggested a substantial decline in mean Indian Summer monsoon rainfall (ISMR) and wet days (rainfall ≥ 1 mm; 7%–14%) over IGP under high‐emission RCP8.5 scenario. The contribution of 90th and 99th percentile days and total rainfall on wet days, seems to be get enhanced in future by 14%–35%, which implies the increase and intensification in rainfall extremes over IGP by the end of the 21st century. Further, the decline in ISMR and negligible changes in annual rainfall over IGP suggest the possible shift of monsoon regime during the later months of the year in warming climate. Thus, findings of present study may play a crucial role in predicting the ISMR and rainfall extremes over the IGP. Therefore, it can be useful for scientists and policymakers to plan and implement mitigation strategies.

Performance Analysis of a Portable Low-Cost SDR-Based Ionosonde

This work presents a software-defined radio ionosonde (ISDR) developed at the Abdus Salam International Centre for Theoretical Physics (Italy) and the Institute of Radio Astronomy (Ukraine) and installed at the Ukrainian Antarctic Station in 2017. For the first time, the results of the long-term data comparison of the ISDR with the conventional ionosonde IPS-42 produced by KEL Aerospace are presented and discussed. The matching of the ionograms obtained during the whole year of 2021, as well as a comparison of the critical frequencies and virtual heights of F, E, and Es layers manually scaled from the ionograms showed that the ISDR has a similar level of performance to IPS-42. At the same time, the ISDR is a more versatile instrument that supports a bistatic operation, provides Doppler measurements and polarization information, and has a significantly lower cost and transmission power. Different configurations of the ISDR are considered. The basic configuration allows for using the ISDR as a conventional vertical ionospheric sounder. An enhanced configuration of the ISDR allows for oblique sounding, as well as polarization information that enables the O- and X-propagation modes of the ionospheric signal to be distinguished. The enhanced passive version of the ISDR was successfully tested onboard the research vessel “Noosfera” on distances up to 1,400 km from the transmitting ISDR.

Identifying the changes in winter monsoon characteristics over the Indian subcontinent due to Arabian Sea warming

This study investigated the impact of the Arabian Sea (AS) warming in modulating the winter precipitation over the Indian subcontinent and associated dynamical response such as subtropical jet variability using regional climate model, RegCM4.7 of the International Centre for Theoretical Physics (ICTP). In this regard, a control run (RegCTL) is forced by real sea surface temperature (SST), and two sensitivity experiments with uniformly increased SST over AS by 0.45 °C (RegSST45) and 0.90 °C (RegSST90) are performed. The results obtained from a control experiment (RegCTL) are compared with corresponding values from RegSST45 and RegSST90 to assess the warming impact. The model (RegCTL) realistically simulates the circulation features, precipitation, and temperature over the Indian subcontinents in the winter season (November–December-January-February; NDJF) during 2006–2015. It is found that AS warming increases the precipitation over most parts of India during winter. The precipitation response varies with the month (NDJF) and the magnitude of AS warming. In general, precipitation is found to intensify with increasing AS warming over northern India and adjoining south Asian nations like Afghanistan, Pakistan, and some parts of Burma and Nepal. The strengthening of STJ is observed due to AS warming (RegSST45). The strengthening of the subtropical jet (STJ) persists with an intensification of AS warming (RegSST90); however, the magnitude of strengthening is less than RegSST45, which is consistent with the corresponding increase of precipitation over India. Cold wave duration is found to be significantly sensitive to the intensity of AS warming. It is noticed that the AS warming increases the cold wave duration over the northern part of India with major increases over the western Himalayan region.

Influence of initial soil moisture in a regional climate model study over West Africa – Part 1: Impact on the climate mean

Abstract. The impact of soil moisture initial conditions on the mean climate over West Africa was examined using the latest version of the regional climate model of the International Centre for Theoretical Physics (RegCM4) at a 25 km horizontal resolution. The soil moisture reanalysis of the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis of the 20th century (ERA-20C) was used to initialize the control experiment, while its minimum and maximum values over the entire domain were used to establish the respective initial dry and wet soil moisture conditions (hereafter referred to as dry and wet experiments, respectively). For the respective control, wet and dry experiments, an ensemble of five runs from June to September was performed. In each experiment, we analyzed the two idealized simulations most sensitive to the dry and wet soil moisture initial conditions. The impact of soil moisture initial conditions on precipitation in West Africa is linear over the Central and West Sahel regions, where dry (wet) experiments lead to a rainfall decrease (increase). The strongest precipitation increase is found over the West Sahel for wet experiments, with a maximum change value of approximately 40 %, whereas the strongest precipitation decrease is found for dry experiments over the Central Sahel, with a peak change of approximately −4 %. The sensitivity of soil moisture initial conditions can persist for 3–4 months (90–120 d) depending on the region. However, the influence on precipitation is no longer than 1 month (between 15 and 30 d). The strongest temperature decrease is located over the Central and West Sahel, with a maximum change of approximately −1.5 ∘C in wet experiments, whereas the strongest temperature increase is found over the Guinea coast and Central Sahel for the dry experiments, with a maximum change of around 0.6 ∘C. A significant impact of soil moisture initial conditions on the surface energy fluxes is noted: in the wet (dry) experiments, a cooling (warming) of the surface temperature is associated with a decrease (increase) in sensible heat flux, an increase (decrease) in latent heat flux and a decrease (increase) in the boundary layer depth. Part 2 of this study (Koné et al., 2022) investigates the influence of soil moisture initial conditions on climate extremes.

Beyond the Words in Print: Identity Construction in Messages of Condolence

Death is part of human existence. When a person hears the news of someone’s death, it is very common for that person to express their feelings about it. This feeling is in the form of condolences which express the speaker’s sorrow, and condolences fall into the category of speech act. Semantically, condolences have a social meaning which refers to language use. Identities are created in relationships with others, and condolences are major platforms for the construction of identities, in that, existing relationships are, clearly, manifested in the messages that sympathizers expressed. Using a qualitative approach, the study analyzed twenty condolence messages which were purposely sampled from condolence messages posted in the portals of International Centre for Theoretical Physics (ICTP), when one of its members passed away. The analysis of the data revealed two main identity types enacted for the deceased: role identity and Social Identity. The major Role identity enacted, metaphorically, was Father while the least role was Achiever. Second, identity as an International Figure was dominant with the Social roles, but Good Personality was used less frequently. The present study adds to studies in identity construction, in general, and studies in condolence messages, in specific.

Mudumbai Seshachalu Narasimhan (1932–2021)

On May 15, 2021, the eminent Indian mathematician Mudumbai Seshachalu Narasimhan passed away at his home in Bangalore. His work in the field of geometry is internationally recognised, having deep connections with different branches of mathematics and theoretical physics. Narasimhan spent much of his career at the Tata Institute of Fundamental Research (TIFR) in Mumbai, where he was a key figure in the creation and development of the internationally acclaimed modern Indian school of algebraic geometry. After retiring from TIFR, from 1993 to 1999, Narasimhan was Head of the Mathematics Section of the International Centre for Theoretical Physics (ICTP) in Trieste, an institution created in 1964 by the Pakistani 1979 Nobel Laureate in Physics Abdus Salam.

Simulation of Rainfall over Bangladesh Using Regional Climate Model (RegCM4.7)

Regional climate model is a scientific tool to monitor present climate change and to provide reliable estimation of future climate projection. In this study, the Regional Climate Model version 4.7 (RegCM4.7) developed by International Centre for Theoretical Physics (ICTP) has been adopted to simulate rainfall scenario of Bangladesh. The study examines model performance of rainfall simulation through the period of 1991-2018 with ERA-Interim75 data of 75 km horizontal resolution as lateral boundaries, downscaled at 25km resolution using the mixed convective precipitation scheme; MIT-Emanuel scheme over land and Grell scheme with Fritsch-Chappell closure over ocean. The simulated rainfall has been compared both at spatial and temporal scales (monthly, seasonal and annual) with observed data collected from Bangladesh Meteorological Department (BMD) and Climate Research Unit (CRU). Simulated annual rainfall showed that the model overestimated in most of the years. Overestimation has been observed in the monsoon and underestimation in pre-monsoon and post-monsoon seasons. Spatial distribution of simulated rainfall depicts overestimation in the southeast coastal region and underestimation in the northwest and northeast border regions of Bangladesh. Better estimation of rainfall has been found in the central and eastern parts of the country. The simulated annual rainfall has been validated through the Linear Scaling bias correction method for the years of 2016, 2017, and 2018 considering the rainfall of 1991-2015 as reference. The bias correction with linear scaling method gives fairly satisfactory results and it can be considered in the future projection of rainfall over Bangladesh.

Projected shifts in Köppen climate zones over China and its national ecological security shelter zones

<p indent="0mm">Based on a set of five regional climate model 21st century climate change simulations, this study assesses future changes in Köppen-Trewartha climate types in China and its five national ecological security shelter zones. The regional climate model, the Abdus Salam International Centre for Theoretical Physics (ICTP) regional climate model RegCM4, is driven by five different global climate models, CSIRO-Mk3-6-0, EC-EARTH, HadGEM2-ES, MPI-ESM-MR and NorESM1-M, at a grid spacing of <sc>25 km</sc> under the representative concentration pathway RCP4.5. These global climate models were selected because of their high horizontal resolution and their good performance in reproducing temperature and precipitation over China. The model configuration used was customized for better performance over China. Bias correction was applied to the simulated temperature and precipitation before calculating the climate types. By the end of the 21st century (2069–2098), the annual mean temperature over China is projected to increase by 2.4°C relatives to the present day (1981–2010) annual mean temperature, with the greatest warming (&gt; <sc>2.8°C)</sc> occurring in the Three Rivers Headwaters region. The annual mean precipitation change shows a general increase in most parts of China, except for a slight decrease (&lt; 7%) in southwestern China. The increase is more pronounced over northwestern China. The distribution of climate types was well reproduced by the simulations. A subtropical humid (Cr) climate mainly covers the regions south of the Yangtze River over eastern China. Southwestern China is dominated by a subtropical winter dry (Cw) climate. The Tibetan Plateau is mostly described as tundra (FT) and arid (type B) climate. Dry arid (BW) and semiarid (BS) climates cover most of the northern regions of 35°N except over northeastern China, where temperate continental (Dc) and subarctic continental (Ec) climates exist. Compared to the present-day climates, a change of 22% in the climate types is projected to occur over the whole Chinese territory by the end of the 21st century. The changes are most significant over the Tibetan Plateau and along the climate transition zone of the Qinling Mountains-Huaihe River over China, with a dominant retreat of FT due to the profound warming and an expansion of BS and Cw being projected for the former, and a replacement of temperature oceanic (Do) by Cw being projected for the latter. Over northeastern China, the main projected change in the climate types is the replacement of Ec by Dc. Tropical wet-dry (Aw) climates will occur over all of Hainan Island. The analysis showed that most changes in climate types are driven by temperature rather than precipitation. For the national shelter zones, climate types will change by 24% over all the areas. Profound changes of ~40% will occur in the shelter zones of the Qinghai-Tibet Plateau and the Sichuan-Yunnan-Loess Plateau, followed by those in the northeastern forest. More specifically, over the Qinghai-Tibet Plateau, the replacement of FT by subarctic oceanic (Eo), BS, Ec, and Dc climates is projected to occur. While FT (62%) and BS (26%) dominate this region currently day, BS (38%) and FT (24%) will account for a greater proportion of the region by the end of the 21st century. The change in climate types on the Sichuan-Yunnan-Loess Plateau is characterized by the expansion of Cw and BS and a loss of FT. Replacement of Ec by Dc is projected in the northeastern forest shelter zone, indicating a major retreat of subarctic coniferous forest there. Greater ecological vulnerability and risks in the future under climate change are expected in the zones. Generally, the changes are in good agreement among the individual simulations, indicating a small uncertainty in the projections.

Long-Term Projection of Water Cycle Changes over China Using RegCM

The global water cycle is becoming more intense in a warming climate, leading to extreme rainstorms and floods. In addition, the delicate balance of precipitation, evapotranspiration, and runoff affects the variations in soil moisture, which is of vital importance to agriculture. A systematic examination of climate change impacts on these variables may help provide scientific foundations for the design of relevant adaptation and mitigation measures. In this study, long-term variations in the water cycle over China are explored using the Regional Climate Model system (RegCM) developed by the International Centre for Theoretical Physics. Model performance is validated through comparing the simulation results with remote sensing data and gridded observations. The results show that RegCM can reasonably capture the spatial and seasonal variations in three dominant variables for the water cycle (i.e., precipitation, evapotranspiration, and runoff). Long-term projections of these three variables are developed by driving RegCM with boundary conditions of the Geophysical Fluid Dynamics Laboratory Earth System Model under the Representative Concentration Pathways (RCPs). The results show that increased annual average precipitation and evapotranspiration can be found in most parts of the domain, while a smaller part of the domain is projected with increased runoff. Statistically significant increasing trends (at a significant level of 0.05) can be detected for annual precipitation and evapotranspiration, which are 0.02 and 0.01 mm/day per decade, respectively, under RCP4.5 and are both 0.03 mm/day per decade under RCP8.5. There is no significant trend in future annual runoff anomalies. The variations in the three variables mainly occur in the wet season, in which precipitation and evapotranspiration increase and runoff decreases. The projected changes in precipitation minus evapotranspiration are larger than those in runoff, implying a possible decrease in soil moisture.

Remote Laboratory for E-Learning of Systems on Chip and Their Applications to Nuclear and Scientific Instrumentation

Configuring and setting up a remote access laboratory for an advanced online school on fully programmable System-on-Chip (SoC) proved to be an outstanding challenge. The school, jointly organized by the International Centre for Theoretical Physics (ICTP) and the International Atomic Energy Agency (IAEA), focused on SoC and its applications to nuclear and scientific instrumentation and was mainly addressed to physicists, computer scientists and engineers from developing countries. The use of e-learning tools, which some of them adopted and others developed, allowed the school participants to directly access both integrated development environment software and programmable SoC platforms. This facilitated the follow-up of all proposed exercises and the final project. During the four weeks of the training activity, we faced and overcame different technology and communication challenges, whose solutions we describe in detail together with dedicated tools and design methodology. We finally present a summary of the gained experience and an assessment of the results we achieved, addressed to those who foresee to organize similar initiatives using e-learning for advanced training with remote access to SoC platforms.

A reclassification of markers for mixed reality environments

PurposeThis paper presents a reclassification of markers for mixed reality environments that is also applicable to the use of markers in robot navigation systems and 3D modelling. In the case of Augmented Reality (AR) mixed reality environments, markers are used to integrate computer generated (virtual) objects into a predominantly real world, while in Augmented Virtuality (AV) mixed reality environments, the goal is to integrate real objects into a predominantly virtual (computer generated) world. Apart from AR/AV classifications, mixed reality environments have also been classified by reality; output technology/display devices; immersiveness as well as by visibility of markers.Design/methodology/approachThe approach adopted consists of presenting six existing classifications of mixed reality environments and then extending them to define new categories of abstract, blended, virtual augmented, active and smart markers. This is supported with results/examples taken from the joint Mixed Augmented and Virtual Reality Laboratory (MAVRLAB) of the Ulster University, Belfast, Northern Ireland; the Abdus Salam International Centre for Theoretical Physics (ICTP), Trieste, Italy and Santasco SrL, Regio Emilia/Milan, Italy.FindingsExisting classification of markers and mixed reality environments are mainly binary in nature and do not adequately capture the contextual relationship between markers and their use and application. The reclassification of markers into abstract, blended and virtual categories captures the context for simple use and applications while the categories of augmented, active and smart markers captures the relationship for enhanced or more complex use of markers. The new classifications are capable of improving the definitions of existing simple marker and markerless mixed reality environments as well as supporting more complex features within mixed reality environments such as co-location of objects, advanced interactivity, personalised user experience.Research limitations/implicationsIt is thought that applications and devices in mixed reality environments when properly developed and deployed enhances the real environment by making invisible information visible to the user. The current work only marginally covers the use of internet of things (IoT) devices in mixed reality environments as well as potential implications for robot navigation systems and 3D modelling.Practical implicationsThe use of these reclassifications enables researchers, developers and users of mixed reality environments to select and make informed decisions on best tools and environment for their respective application, while conveying information with additional clarity and accuracy. The development and application of more complex markers would contribute in no small measure to attaining greater advancements in extending current knowledge and developing applications to positively impact entertainment, business and health while minimizing costs and maximizing benefits.Originality/valueThe originality of this paper lies in the approach adopted in reclassifying markers. This is supported with results and work carried out at the MAV Reality Laboratory of Ulster University, Belfast–UK, the Abdus Salam International Centre for Theoretical Physics (ICTP), Trieste-Italy and Santasco SrL, Regio Emilia, Milan–Italy. The value of present research lies in the definitions of new categories as well as the discussions of how they improve mixed reality environments and application especially in the health and education sectors.

Views of an Octogenarian on a Path to a Nonagenarian: The Field of General Symmetries and its Applications

I am on the path from my eightieth to my ninetieth birthday, or from an octogenarian to a nonagenarian. It is certainly encouraging to have opportunities on this path to talk about personal recollections and my views on my work and activities towards the development of the field—our field—of understanding and applying models in physical and related sciences based on the infinite set of mathematical notions of symmetries in their most general sense and with all their facets. I plan to talk today about the first part of my path in my native city Berlin, followed by the University of Marburg and jointly at the International Centre for Theoretical Physics in Trieste.

Doppler vertical sounding of the ionosphere at the Akademik Vernadsky station

The paper aims at providing the technical information about Doppler vertical sounding of the ionosphere that started at the Ukrainian Antarctic Akademik Vernadsky station since 2017; developing the technique for processing and visualization of data of vertical sounding of the ionosphere in the form of height-time diagrams of median values of ionospheric parameters; demonstrating the capabilities of this technique using the results obtained during the first year of observations, namely the background variations of ionospheric parameters as well as examples of observations of travelling ionospheric disturbances (TID). The methods used in the paper are the following: the vertical sounding of the ionosphere using the IPS-42 ionosonde operating at Akademik Vernadsky station since 1982; Doppler vertical sounding of the ionosphere by the portable ionosonde developed and manufactured in collaboration between the Abdus Salam International Centre for Theoretical Physics (ICTP) and Institute of Radio Astronomy of the National Academy of Sciences of Ukraine (IRA NASU); calculating the height-time diagrams of ionospheric parameters obtained using the data of both ionosondes; and original technique for estimating the median height-time diagrams as background monthly averaged characteristics of the ionosphere. Seasonal and diurnal variations of plasma frequencies, vertical plasma velocities, as well as the signal-to-noise ratio and the probability of the registration of signals are shown using the median height-time diagrams of the corresponding parameters for the first year of synchronous observations by the two ionosondes. The features and potential areas of application of median ionospheric height-time diagrams are discussed. They can be used to calculate automatically variations of maximum usable frequency for a radio link of the specified length. Examples of TID registrations in variations of virtual heights of reflection and Doppler frequency shifts (DFS) of the signals are presented. It is shown that the comparison of TID manifestations in variations of virtual heights and DFS can be used to select a more appropriate model of TID among the models of perfectly reflecting moving surface or three-dimensional plasma density waves traveling through a real ionospheric layer. It could be concluded that simultaneous operation of two ionosondes at the Akademik Vernadsky station has allowed to significantly expand the amount and quality of objective information about the ionospheric behavior over the Antarctic Peninsula.

Effects of Subgrid Terrain Radiative Forcing on the Ability of RegCM4.1 in the Simulation of Summer Precipitation Over China

AbstractWe implemented a subgrid terrain radiative forcing (STRF) scheme into the International Centre for Theoretical Physics, Italy, Regional Climate Model Version 4.1 (RegCM4.1) and evaluated its impacts on the summer precipitation simulation over China by comparing the model results from the experiments with and without the STRF scheme. The RegCM4.1 without the STRF scheme simulates strong East Asian summer monsoon and overestimates the summer precipitation over China. Adopting the STRF scheme in the RegCM4.1 improves the representation of surface radiation process over complex terrains, by reducing the net gain of the surface radiation energy over the Tibetan Plateau (TP). As a result, the heat released from the surface to the overlying air column decreases, thus suppressing the development of local convection over the TP. In addition, the weakened TP thermal forcing due to the STRF effect reduces the land‐sea thermal contrast, resulting in a weakened East Asian summer monsoon that produces less transport of water vapor from tropical oceans and hence weakens summer precipitation over China. Our analysis indicates that such improvement in the precipitation simulation induced by the STRF effect is mainly due to the improved simulation of precipitation intensity, particularly that associated with the moderate and heavy precipitation events, and convective processes.

Climate change of the 21st century over China from the ensemble of RegCM4 simulations

Climate change in the 21st century over China and its different sub-regions is investigated in the study, based on the ensemble of a set of dynamical downscaling experiments over East Asia. The model employed in the experiments is the International Center for Theoretical Physics’ Regional Climate Model, version 4 (RegCM4), at 25-km grid spacing, driven by five different CMIP5 (phase 5 of the Coupled Model Intercomparison Project) global models under the Representative Concentration Pathways RCP4.5 and RCP8.5. The model version used was customized for better performance over the region. Ten sub-regions of China were defined, with consideration paid to local economic and societal developments, vulnerability of ecosystems, and sensitivity to future climate changes. A substantial warming in the future in China is projected, and this warming is more pronounced over the Tibetan Plateau during DJF (December-January-February) and Northwest China (where dry climate prevails) during JJA (June-July-August). A broad increase in temperature extreme indices—Namely, TXx (annual maximum daily maximum surface air temperature) and TNn (annual minimum daily minimum surface air temperature)—is reported, along with increased mean temperature. The results suggest more frequent and intense heat waves in the warm seasons, and thus more risks in terms of human health and mortality, over the sub-regions of Beijing-Tianjin-Hebei, the Yangtze Delta, the Guangdong-Hong Kong-Macao Greater Bay Area, and the Cross-Taiwan Strait Coasts, with their dense cities and populations. Meanwhile, the warming over the Tibetan Plateau may lead to degradation of frozen soil and glacial melt, and thus a greater frequency of related geological hazards, while increased evapotranspiration following the warming over the Arid and Semi-arid Northwest and Losses Plateau sub-regions may worsen the situation with respect to water resource shortages. Precipitation change in DJF shows a prevailing increase in northern China, with good agreement among the ensemble members. The increase is largest in the Northwest China sub-region. In southern China, small changes with a slight decrease in the southern part of the Yunnan-Guizhou Plateau are found. In JJA, precipitation increases over western China, the northern part of Northeast China, and the Yellow-Huai River basins, and shows small changes over other areas. A general increase in the precipitation extreme index (RX1day, the annual maximum 1-day precipitation) is found over the whole country, indicating more extreme precipitation events in the future. For the CDD index (the largest number of consecutive days when the daily precipitation amount is less than 1 mm), a general increase in the north and a decrease in the south are found. Regarding the increases of heavy precipitation events, the Arid and Semi-arid Northwest and Losses and Tibetan Plateau sub-regions, with their fragile ecosystems, may experience relatively more landslide and debris flow events; while over the more populated sub-regions, special concern is needed with respect to the likely greater frequency and more intense nature of flooding and urban-flooding events. Quantitatively, the increases in annual mean temperature, TXx, and TNn in the mid-21st (2041–2060) century relative to the present day (1986–2005) over the whole of China under RCP4.5/RCP8.5 are 1.6/2.2°C, 1.7/2.2°C, and 1.9/2.7°C, respectively. For precipitation, RX1day, and CDD, the values of change are 4%/5%, 9%/12%, and both around −2 d, respectively. The changes become more pronounced with time. By the end of the 21st century (2081–2098), under the higher scenario of RCP8.5, the changes in annual mean temperature, TXx, TNn, precipitation, RX1day and CDD are 4.6, 4.7, 5.5°C, 12%, 25%, and −4 d, respectively. Finally, the deficiencies and uncertainties that remain in projecting the future climate over the region are also outlined and discussed in the paper.

Schooling Africa: Computational Materials Science education and research

The African School of Electronic Structure Methods and Applications (ASESMA) [1 – 7] is a series of workshops held every two years in different sub-Saharan countries, designed to foster a collaborative network for research and higher education in Africa. Participants are drawn from across the continent through a competitive process, and the lecturers and mentors are outstanding scientists from across the world including Africa. ASESMA is administered by the International Centre for Theoretical Physics (ICTP), and the primary sponsor is the International Union of Pure and Applied Physics (IUPAP). The core guiding principle is that computation makes it possible for world-class research to be done with modest investment, and it is an essential part of education for the future. The skills acquired are useful for teaching at the university level and are transferable to other disciplines. The participants are the teachers who will educate future generations of African scientists.