| 1. |
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| 2. |
- Thomas, HS, et al.
(författare)
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- 2019
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swepub:Mat__t
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| 3. |
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| 4. |
- Drake, TM, et al.
(författare)
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Surgical site infection after gastrointestinal surgery in children: an international, multicentre, prospective cohort study
- 2020
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Ingår i: BMJ global health. - : BMJ. - 2059-7908. ; 5:12
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Tidskriftsartikel (refereegranskat)abstract
- Surgical site infection (SSI) is one of the most common healthcare-associated infections (HAIs). However, there is a lack of data available about SSI in children worldwide, especially from low-income and middle-income countries. This study aimed to estimate the incidence of SSI in children and associations between SSI and morbidity across human development settings.MethodsA multicentre, international, prospective, validated cohort study of children aged under 16 years undergoing clean-contaminated, contaminated or dirty gastrointestinal surgery. Any hospital in the world providing paediatric surgery was eligible to contribute data between January and July 2016. The primary outcome was the incidence of SSI by 30 days. Relationships between explanatory variables and SSI were examined using multilevel logistic regression. Countries were stratified into high development, middle development and low development groups using the United Nations Human Development Index (HDI).ResultsOf 1159 children across 181 hospitals in 51 countries, 523 (45·1%) children were from high HDI, 397 (34·2%) from middle HDI and 239 (20·6%) from low HDI countries. The 30-day SSI rate was 6.3% (33/523) in high HDI, 12·8% (51/397) in middle HDI and 24·7% (59/239) in low HDI countries. SSI was associated with higher incidence of 30-day mortality, intervention, organ-space infection and other HAIs, with the highest rates seen in low HDI countries. Median length of stay in patients who had an SSI was longer (7.0 days), compared with 3.0 days in patients who did not have an SSI. Use of laparoscopy was associated with significantly lower SSI rates, even after accounting for HDI.ConclusionThe odds of SSI in children is nearly four times greater in low HDI compared with high HDI countries. Policies to reduce SSI should be prioritised as part of the wider global agenda.
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| 5. |
- Hassan, M. A., et al.
(författare)
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High-resolution estimates of diffuse fraction based on dynamic definitions of sky conditions
- 2021
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Ingår i: Renewable energy. - : Elsevier Ltd. - 0960-1481 .- 1879-0682. ; 169, s. 641-659
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Tidskriftsartikel (refereegranskat)abstract
- Accurate monitoring and operation of solar power systems require high-resolution solar radiation measurements and precise separation models. This study aims to improve the accuracy of classic diffuse fraction-clearness index piecewise separation models by applying data-driven classifications of sky conditions. This is achieved through a novel outlier-insensitive clustering algorithm and shape prescriptive modeling, applied to 1-, 10-, 30-, and 60-min ground measurements from 4 different locations in the MENA region. This study shows that classifications of sky conditions are not uniform among the selected locations even though all stations fall in the arid desert climate category. This highlights the importance of extracting the sky conditions from measurements rather than using available classifications in the literature. The selection of the number of clusters has to undergo optimization. The number of clusters is also a function of the time resolution. One of the selected locations shows four optimal clusters for 1-min data and six clusters for 60-min data. All developed piecewise separation models show high accuracy and stability with the mean bias errors approaching zero values and the mean absolute errors ranging between 8.7 and 11.8%. The models also outperform existing ones and have good generalization capabilities under the same climate classification.
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| 6. |
- Ahmad, Fawad, et al.
(författare)
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Synthesis of New Naphthyl Aceto Hydrazone-Based Metal Complexes : Micellar Interactions, DNA Binding, Antimicrobial, and Cancer Inhibition Studies
- 2021
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Ingår i: Molecules. - : MDPI AG. - 1431-5157 .- 1420-3049. ; 26:4
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, naphthyl acetohydrazide (HL) ligand was prepared and used for the synthesis of new six amorphous transition metal (Co(II), Ni(II), Cu(II), Zn(II), Pb(II), Cd(II)) complexes. All the compounds were characterized by elemental analysis, UV-vis, FT-IR, 1H- and 13C-NMR, and Matrix-Assisted Laser Desorption Ionization (MALDI). The solubilization study was carried out by estimating the interaction between the metal complexes with surfactants viz. sodium stearate (SS) and Cetyltrimethylammonium bromide (CTAB). UV-Visible spectroscopy was employed to determine partitioning and binding parameters, whereas electrical conductivity measurements were employed to estimate critical micellar concentration (CMC), the extent of dissociation, and free energy of micellization. The CT-DNA interaction of synthesized compounds with DNA represents the major groove binding. The synthesized ligand and metal complexes were also tested against bacterial and fungal strains and it has been observed that Cu(II) complex is active against all the strains except Candida albicans, while Cd(II) complex is active against all bacterial and fungal strains except Pseudomonas. Among all compounds, only the Pd(II) complex shows reasonable activity against cervical cancer HeLa cell lines, representing 97% inhibition.
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| 7. |
- Taj, Muhammad Babar, et al.
(författare)
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Exploring novel fluorine-rich fuberidazole derivatives as hypoxic cancer inhibitors : Design, synthesis, pharmacokinetics, molecular docking, and DFT evaluations
- 2023
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 18:2
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Tidskriftsartikel (refereegranskat)abstract
- Sixteen fuberidazole derivatives as potential new anticancer bioreductive prodrugs were prepared and characterized. The in vitro anticancer potential was examined to explore their cytotoxic properties by employing apoptosis, DNA damage, and proliferation tests on chosen hypoxic cancer cells. Eight substances (Compound 5a, 5c, 5d, 5e, 5g, 5h, 5i, and 5m) showed promising cytotoxicity values compared to the standard control. The potential of compounds was also examined through in silico studies (against human serum albumin), including chem-informatics, to understand the structure-activity relationship (SAR), pharmacochemical strength, and the mode of interactions responsible for their action. The DFT calculations revealed that only the 5b compound showed the lowest ΔET (2.29 eV) while 5i showed relatively highest βtot (69.89 x 10–31 esu), highest αave (3.18 x 10–23 esu), and dipole moment (6.49 Debye). This study presents a novel class of fuberidazole derivatives with selectivity toward hypoxic cancer cells.
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| 8. |
- AlGannas, Nayef S., et al.
(författare)
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Assessment of the levels of antispike SARS-CoV-2 IgG antibodies and their association with clinical characteristics in cohort of patients in Saudi Arabia
- 2022
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Ingår i: Journal of Family Medicine and Primary Care. - : Medknow Publications. - 2249-4863 .- 2278-7135. ; 11:11, s. 7372-7377
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Tidskriftsartikel (refereegranskat)abstract
- Background: Coronavirus disease 2019 (COVID-19) has caused a global public health crisis. The disease is known to be caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, but the detailed characteristics of the immune response to this novel virus have not been fully elucidated yet. In this study, we aimed to determine the level of immunoglobulin G (IgG) antibodies and their correlation with clinical features at three time points postinfection in a group of patients in Saudi Arabia.Method: In this prospective observational study, we collected the demographic and clinical data from 43 polymerase chain reaction (PCR)-confirmed patients and measured the COVID-19 antispike IgG levels at three different visits.Result: The seroconversion rate after COVID-19 infection was 88.4% in the study participants, with no significant changes in the IgG levels through the three visits. The duration of shortness of breath had a significant positive correlation with the IgG level of the patients. Using the logistic regression model, participants having coughs were found to be 12.48 times more likely to develop positive IgG. The IgG levels were less in smokers than nonsmokers [Odds ratio = 6.42 (95% CI 2.11-19.48); P = 0.001].Conclusion: Positive IgG levels have been developed in most COVID-19 patients and did not significantly change over 3 months following the diagnosis. The level of IgG antibodies was found to be significantly associated with the presence of cough, duration of shortness of breath, and the smoking habit of the patients. These findings have clinical and public health significance and need to be validated in larger studies in different populations.
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| 9. |
- Badi, Safaa, et al.
(författare)
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Knowledge and attitudes toward COVID-19 vaccination in Sudan : A cross-sectional study
- 2023
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Ingår i: AIMS Public Health. - : AIMS Press. - 2327-8994. ; 10:2, s. 310-323
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Tidskriftsartikel (refereegranskat)abstract
- Background: Vaccines are an essential part of public health interventions to mitigate the devastating health and non-health impacts of COVID-19 pandemic. Despite the fact that Sudan launched the COVID-19 vaccination program in March 2021, only 10% of the population received their two primary doses of vaccines by the end of May 2022. This delayed uptake of vaccines obviously warrants investigation. Therefore, we have conducted this study to evaluate the knowledge, attitude and acceptance of the general population in Sudan toward COVID-19 vaccines.Methodology: A descriptive cross-sectional community-based study. The data were collected using an electronic questionnaire from 403 individuals living in Khartoum, Sudan. The data were processed using the Statistical Package for Social Sciences (SPSS), and data analysis was performed using appropriate tests.Results: 51% of the participants were found to have sufficient knowledge about the COVID-19 vaccine, and the knowledge level is higher among those educated beyond the secondary school and those who were employed. Among those unvaccinated, only 47% of the participants expressed their intention to take the vaccine when offered to them. The major reason for not trusting the vaccine is safety concerns expressed by 65.5% of the unvaccinated.Conclusion: Higher education levels and employment were associated with an increase in sufficient knowledge about the vaccine in around half of the participants. However, most of participants had not taken the vaccine at the time of the study, and the trust in vaccines is not high. Effective interventions by the health authorities are needed to address these issues in order to accelerate the COVID-19 vaccination program in Sudan.
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| 10. |
- Eltom, Mohamed A., et al.
(författare)
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Increasing prevalence of type 2 diabetes mellitus and impact of ethnicity in north Sudan
- 2018
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Ingår i: Diabetes Research and Clinical Practice. - : ELSEVIER IRELAND LTD. - 0168-8227 .- 1872-8227. ; 136, s. 93-99
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Tidskriftsartikel (refereegranskat)abstract
- Background: Diabetes mellitus constitutes a global health threat, with increasing burden of disease in low and middle-income countries witnessing ongoing epidemiological transition including Sudan.Aims: To study the prevalence of type 2 diabetes mellitus (T2DM) and prediabetes and determine the relationship to gender, age, waist circumference, body mass index, residence and ethnicity among the adult population in north Sudan.Methods: A cross-sectional, population-based study in Northern State and River Nile State using random multi-stage cluster sampling targeting 5376 participants from 14 localities divided into 60 urban and 40 rural clusters. In each cluster, 60 households were studied. Blood glucose level and anthropometric measurements were recorded and a questionnaire containing demographic data was obtained from each participant.Results: The prevalence of T2DM among participants was 18.7% and prediabetes was 12.9%. Among people living with T2DM, 694(71.0%) were known cases of T2DM, whereas 284 (29.0%) were newly diagnosed cases. The significant associated risk factors for T2DM included urban residence (AOR 1.23, 95% CI 1.09-1.41), age above 60 years (AOR 4.77, 95% CI 4.04-5.63), obese BMI (AOR 1.26, 95% CI 1.03-1.55) and central obesity (AOR 1.39, 95% CI 1.14-1.68). Compared to indigenous population, individuals of Egyptian descents (AOR 1.28, 95% CI 1.04-1.57) and mixed origin (AOR 1.24, 95% CI 1.04-1.48) had increased risk of T2DM.Conclusion: The prevalence of T2DM and prediabetes in north Sudan have increased significantly since 1996 with variations between ethnicities which showed to be an independent risk factor for T2DM. Health authorities are recommended to set plans to meet the health needs of these communities.
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| 11. |
- Karim, Sitara, et al.
(författare)
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Examining the interrelatedness of NFTs, DeFi tokens and cryptocurrencies
- 2022
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Ingår i: Finance Research Letters. - : Academic Press Inc - Elsevier Science. - 1544-6123 .- 1544-6131. ; 47
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Tidskriftsartikel (refereegranskat)abstract
- The high volatility of the blockchain markets has driven the attention of investors and market participants to concentrate on the diversification avenues of NFTs, DeFi Tokens, and Cryptocurrencies. We examined the extreme risk transmission of blockchain markets using the quantile connectedness technique at the median, extreme low, and extreme high volatility conditions. We find significant risk spillovers among blockchain markets with strong disconnection of NFTs. Meanwhile, time-varying features characterized various uneven economic circumstances. Overall, NFTs offer greater diversification avenues with substantial risk-bearing potential among other blockchain markets to shelter the investments and minimize extreme risks.
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| 12. |
- Leybourne, Mark, et al.
(författare)
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Preliminary design of the OWEL wave energy converter pre-commercial demonstrator
- 2014
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Ingår i: Renewable energy. - : Elsevier BV. - 0960-1481 .- 1879-0682. ; 61:0, s. 51-56
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Tidskriftsartikel (refereegranskat)abstract
- The consortium responsible for the next stage of development of the OWEL wave energy converter will construct and test a large scale, pre-commercial demonstrator. It is expected that this will be installed at Wave Hub during 2013 and grid connected for a testing period lasting around 12 months. This paper reports on the preliminary design work being undertaken in the development of the marine demonstration device. This concentrates primarily on producing a fully costed design by detailing the hydraulic design and aspects of stability as well as providing insight into various design features such as the power take-off, naval architecture, moorings and control. The design is being largely informed by the results of a 15 month research project funded by the South West Regional Development Agency (SWRDA) in which the performance was determined and a detailed techno-economic model for a large scale OWEL device was generated.
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| 13. |
- Leybourne, Mark T., et al.
(författare)
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A parametric experimental study of the 2D performance of a aucted wave energy converters
- 2010
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Konferensbidrag (refereegranskat)abstract
- Offshore Wave Energy Limited’s “OWEL” wave energy converter is a novel design that uses the forward surging motion of deep water waves to capture and compress air. Uni-directional compressed air flow is used by the device to drive a turbine and generator to produce electricity. Previous experimental studies provided useful initial information about the general operating principles and basic trends in device performance. This paper serves as a progress update of the small scale, 2D experimental work being carried out at the University of Southampton. Testing has investigated the relationships between device performance and wave characteristics as well as trialling a series of different geometric configurations of the model
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| 14. |
- Muschitiello, Francesco, et al.
(författare)
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Fennoscandian freshwater control on Greenland hydroclimate shifts at the onset of the Younger Dryas
- 2015
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Sources and timing of freshwater forcing relative to hydroclimate shifts recorded in Greenland ice cores at the onset of Younger Dryas, similar to 12,800 years ago, remain speculative. Here we show that progressive Fennoscandian Ice Sheet (FIS) melting 13,100-12,880 years ago generates a hydroclimate dipole with drier-colder conditions in Northern Europe and wetter-warmer conditions in Greenland. FIS melting culminates 12,880 years ago synchronously with the start of Greenland Stadial 1 and a large-scale hydroclimate transition lasting similar to 180 years. Transient climate model simulations forced with FIS freshwater reproduce the initial hydroclimate dipole through sea-ice feedbacks in the Nordic Seas. The transition is attributed to the export of excess sea ice to the subpolar North Atlantic and a subsequent southward shift of the westerly winds. We suggest that North Atlantic hydroclimate sensitivity to FIS freshwater can explain the pace and sign of shifts recorded in Greenland at the climate transition into the Younger Dryas.
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| 15. |
- Omer, Abubakr A. M., 1982-, et al.
(författare)
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Plantaricin NC8 αβ rapidly and efficiently inhibits flaviviruses and SARS-CoV-2 by disrupting their envelopes
- 2022
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Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 17:11
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Tidskriftsartikel (refereegranskat)abstract
- Potent broad-spectrum antiviral agents are urgently needed to combat existing and emerging viral infections. This is particularly important considering that vaccine development is a costly and time consuming process and that viruses constantly mutate and render the vaccine ineffective. Antimicrobial peptides (AMP), such as bacteriocins, are attractive candidates as antiviral agents against enveloped viruses. One of these bacteriocins is PLNC8 αβ, which consists of amphipathic peptides with positive net charges that display high affinity for negatively charged pathogen membrane structures, including phosphatidylserine rich lipid membranes of viral envelopes. Due to the morphological and physiological differences between viral envelopes and host cell plasma membranes, PLNC8 αβ is thought to have high safety profile by specifically targeting viral envelopes without effecting host cell membranes. In this study, we have tested the antiviral effects of PLNC8 αβ against the flaviviruses Langat and Kunjin, coronavirus SARS-CoV-2, influenza A virus (IAV), and human immunodeficiency virus-1 (HIV-1). The concentration of PLNC8 αβ that is required to eliminate all the infective virus particles is in the range of nanomolar (nM) to micromolar (μM), which is surprisingly efficient considering the high content of cholesterol (8–35%) in their lipid envelopes. We found that viruses replicating in the endoplasmic reticulum (ER)/Golgi complex, e.g. SARS-CoV-2 and flaviviruses, are considerably more susceptible to PLNC8 αβ, compared to viruses that acquire their lipid envelope from the plasma membrane, such as IAV and HIV-1. Development of novel broad-spectrum antiviral agents can significantly benefit human health by rapidly and efficiently eliminating infectious virions and thereby limit virus dissemination and spreading between individuals. PLNC8 αβ can potentially be developed into an effective and safe antiviral agent that targets the lipid compartments of viral envelopes of extracellular virions, more or less independent of virus antigenic mutations, which faces many antiviral drugs and vaccines.
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| 16. |
- Salih, Abubakr A. M., et al.
(författare)
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Characterization of the Sahelian-Sudan rainfall based on observations and regional climate models
- 2018
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Ingår i: Atmospheric research. - : Elsevier BV. - 0169-8095 .- 1873-2895. ; 202, s. 205-218
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Tidskriftsartikel (refereegranskat)abstract
- The African Sahel region is known to be highly vulnerable to climate variability and change. We analyze rainfall in the Sahelian Sudan in terms of distribution of rain-days and amounts, and examine whether regional climate models can capture these rainfall features. Three regional models namely, Regional Model (REMO), Rossby Center Atmospheric Model (RCA) and Regional Climate Model (RegCM4), are evaluated against gridded observations (Climate Research Unit, Tropical Rainfall Measuring Mission, and ERA-interim reanalysis) and rain gauge data from six arid and semi-arid weather stations across Sahelian Sudan over the period 1989 to 2008. Most of the observed rain-days are characterized by weak (0.1-1.0 mm/day) to moderate ( > 1.0-10.0 mm/day) rainfall, with average frequencies of 18.5% and 48.0% of the total annual rain-days, respectively. Although very strong rainfall events ( > 30.0 mm/day) occur rarely, they account for a large fraction of the total annual rainfall (28-42% across the stations). The performance of the models varies both spatially and temporally. RegCM4 most closely reproduces the observed annual rainfall cycle, especially for the more arid locations, but all of the three models fail to capture the strong rainfall events and hence underestimate its contribution to the total annual number of rain days and rainfall amount. However, excessive moderate rainfall compensates this underestimation in the models in an annual average sense. The present study uncovers some of the models' limitations in skillfully reproducing the observed climate over dry regions, will aid model users in recognizing the uncertainties in the model output and will help climate and hydrological modeling communities in improving models.
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| 17. |
- Salih, Abubakr A. M., et al.
(författare)
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Climate impact of deforestation over South Sudan in a regional climate model
- 2013
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Ingår i: International Journal of Climatology. - : Wiley. - 0899-8418 .- 1097-0088. ; 33:10, s. 2362-2375
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Tidskriftsartikel (refereegranskat)abstract
- This study examines the sensitivity of climate to changes in vegetation cover and land use in South Sudan. The focus lies on the effect of deforestation on precipitation and surface temperature especially during the rainy season. Sensitivity experiments are performed with the third version of the Abdus Salam International Centre for Theoretical Physics Regional Climate Model (RegCM3) where the present forest and vegetation cover south of 10 degrees N in Sudan are replaced by either grass or, as an extreme case, desert. The model experiments were conducted for a time period of almost 21 years, from January 1989 to August 2009, and were preceded by a control experiment to ascertain the fidelity of the model simulations. The experiments indicate that the vegetation changes affect precipitation and surface temperature in both Southern and Central Sudan significantly although the land cover changes were imposed only in the south. The precipitation during the rainy season (June through September) was reduced in the perturbed region by about 0.1-2.1 mm d(-1) for the desert scenario and by 0.1-0.9 mm d(-)1 for the grass scenario. The surface temperature increases by about 1.2 and 2.4 degrees C in the grass and desert scenario, respectively. The precipitation reduction is thus not only local but also extends to Central Sudan and neighbouring regions. The study demonstrates significant dependency for Southern and Central Sudan precipitation on the land use in Southern Sudan and indicates that the deforestation has both local and non-local regional climatic effects.
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| 18. |
- Salih, Abubakr A. M., et al.
(författare)
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Lagrangian tracing of Sahelian Sudan moisture sources
- 2015
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Ingår i: Journal of Geophysical Research - Atmospheres. - 2169-897X .- 2169-8996. ; 120:14, s. 6793-6808
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Tidskriftsartikel (refereegranskat)abstract
- The Sahelian Sudan is an arid to semiarid region that depends on the seasonal rainfall as the main source of water, but its rainfall has large interannual variability. Such dry regions usually have their main moisture sources elsewhere; thus, the rainfall variability is directly related to the moisture transport. This study seeks to identify source regions of water vapor for Sahelian Sudan during the monsoon period, from July to September. We have used the Lagrangian trajectory model FLEXPART driven by ERA-Interim reanalysis for the time period 1998 to 2008. The results show that most of the air masses that reach this region during the monsoon period have their major origins over the Arabian Peninsula, Central Africa, or are associated with the tropical easterly jet. Flow associated with Intertropical Convergence Zone contributes almost half of the total precipitated water; most of it comes from Central Africa. This suggests that moisture recycling is the major contributor, compared to Oceanic sources. The flows from the northeast (Arabian Peninsula and north Asia) and east (Horn of Africa and north Indian Ocean) contribute about one third of the precipitated water. The rest of precipitated water comes from the Mediterranean, subtropical Atlantic, and western Sahel, all with smaller contribution. Our results also indicate that different subregions of Sahelian Sudan have different moisture sources. Such result needs to be taken into account in seasonal forecasting practices.
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| 19. |
- Salih, Abubakr A. M., 1980-
(författare)
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On Sahelian-Sudan rainfall and its moisture sources
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The African Sahel is one of the most vulnerable regions to climate variability at different time scales. It is an arid to semi-arid region with limited water resources. The summer rainfall is one of these sources, but it exhibits pronounced interannual variability. This thesis presents several aspects of Sahelian Sudan rainfall. Sudan is located at the eastern fringe of the Sahel and its least studied part. We have examined the impact of tropical deforestation on the rainfall, the moisture sources of the region and the temporal characteristics of the observed and modeled rainfall. In a sensitivity study we performed three simulations, one control simulation and then setting the surface condition of South Sudan to either grass or desert conditions. The rainfall was reduced by 0.1 − 0.9 in the grass scenario and by 0.1 − 2.1 mm day−1 (hereafter mm d−1) in the desert scenario. These changes also propagated northward into Sahelian Sudan, indicating a remote impact. The total moisture convergence into Sahelian Sudan was reduced by 11.5% and 21.9% for grass and desert conditions, respectively. The change in moisture convergence into the region motivated a comprehensive analysis of the moisture sources for the region. Two different modeling approaches, Lagrangian and Eulerian, were applied to identify the moisture sources and quantify their contributions to the total annual rainfall budget. The analysis shows that atmospheric flows associated with the Inter-Tropical Convergence Zone (ITCZ), e.g. from Guinea Coast, Central African and Western Sahel, brings about 40% − 50% of the annual moisture supply, while local evaporation adds about 20%. The rest of the moisture comes from the Mediterranean, Arabian Peninsula and the Southern part of the Indian Ocean. While there were differences in the details between the results from the two modeling approaches, they agree on the larger scale results. In an attempt to characterize the temporal character of the rainfall, observed and modeled daily rainfall from different regional climate models was classified into five categories: weak (0.1 −1.0), moderate (>1.0 − 10.0), moderately strong (>10.0 − 20.0), strong (>20.0 − 30.0), and very strong (>30.0) mm d−1. We found that most rain-days were in the weak to moderate rainfall categories, accounting for 60% − 75%. Days that have strong rainfall represent about 6% of the total rain-days, yet they represent about 28% − 48% of the total amount of the annual rainfall. Regional climate models fail to produce the strong rainfall, instead most of the modeled rain-days are in the moderate category and consequently the models overestimated the number of rain-days per year.
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| 20. |
- Salih, Abubakr A. M., et al.
(författare)
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Sources of Sahelian-Sudan moisture : Insights from a moisture-tracing atmospheric model
- 2016
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Ingår i: Journal of Geophysical Research - Atmospheres. - 2169-897X .- 2169-8996. ; 121:13, s. 7819-7832
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Tidskriftsartikel (refereegranskat)abstract
- The summer rainfall across Sahelian-Sudan is one of the main sources of water for agriculture, human, and animal needs. However, the rainfall is characterized by large interannual variability, which has attracted extensive scientific efforts to understand it. This study attempts to identify the source regions that contribute to the Sahelian-Sudan moisture budget during July through September. We have used an atmospheric general circulation model with an embedded moisture-tracing module (Community Atmosphere Model version 3), forced by observed (1979-2013) sea-surface temperatures. The result suggests that about 40% of the moisture comes with the moisture flow associated with the seasonal migration of the Intertropical Convergence Zone (ITCZ) and originates from Guinea Coast, central Africa, and the Western Sahel. The Mediterranean Sea, Arabian Peninsula, and South Indian Ocean regions account for 10.2%, 8.1%, and 6.4%, respectively. Local evaporation and the rest of the globe supply the region with 20.3% and 13.2%, respectively. We also compared the result from this study to a previous analysis that used the Lagrangian model FLEXPART forced by ERA-Interim. The two approaches differ when comparing individual regions, but are in better agreement when neighboring regions of similar atmospheric flow features are grouped together. Interannual variability with the rainfall over the region is highly correlated with contributions from regions that are associated with the ITCZ movement, which is in turn linked to the Atlantic Multidecadal Oscillation. Our result is expected to provide insights for the effort on seasonal forecasting of the rainy season over Sahelian Sudan.
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