Lower Tropospheric Temperature Variability Over the USA: a GIS Approach

We use the high resolution North American Regional Analysis (NARR) dataset to build for the United States a Temperature Change Index (TCI) based on four contributing variables derived from the layer-averaged temperature and lapse rate of the 1000mb - 700mb layer (near-surface to 3000 meters) for the 1979-2008 period. The analysis uses Geographic Information Systems (GIS) methods to identify distinct regional patterns based on aggregate temperature trends and variability scores. The resulting index allows us to identify and compare regions that experience high (low) temperature trends and variability that are referred to as hot spots (cold spots). The upper Midwest emerges as the region that experiences the largest increases and variability, due to the large magnitude of variability and trends of all variables. In contrast, the lowest TCI scores are observed over southeastern regions and the Rocky Mountains. Regarding landscape characteristics, high TCI scores occur mostly over agricultural lands (thus implying the problem of temperature variability-dependant crop yields) while low scores generally prevail over forests. At a seasonal time scale, the largest and most contrasting TCI scores occur during the winter and, to a lesser extent, fall seasons. All variables used to build the TCI show well defined seasonal patterns and differences, especially between winter and summer. Our method, based on the use of thickness layers, provides a more complete analysis than methods based on monolevel data and confirms that temperature is a robust component of climate change in general and must be included in any study that deals with vulnerability assessment of climate change risks

Les Niayes du Littoral Nord du Senegal: Processus de Mise en Place, Salinisation des eaux Souterranies et des Sols

L’espace couvert par les Niayes fait partie des secteurs les plus fertiles du pays. Il subit actuellement un processus de dégradation des systèmes de production dont la salinisation de la nappe constitue le facteur dominant. L’objet de cette contribution est d’analyser la salinisation des eaux souterraines et des sols dans les Niayes et particulièrement dans les différents sites d’étude notamment le lac Wouye, le lac Tanma, les villages de Taré et de Darou Mboumbaye. La méthodologie déployée est essentiellement basée sur le prélèvement et l’analyse au laboratoire. Elle a permis de mesurer la salinité des sols et des eaux souterraines de la nappe des sables quaternaires en 2010 et 2018. Ainsi, les résultats démontrent une dégradation progressive des eaux d’irrigation et une faible salinité dans le complexe absorbant. Par conséquent, la quasi-totalité des terres est abandonnée dans les sites étudiés à cause de l’alcalinisation mais surtout la salinisation des eaux souterraines qui constitue la principale source d’irrigation. Ainsi, un nombre important de maraîchers a perdu une bonne partie des terres agricoles : lac Wouye (60 %), lac Tanma (50 %), Taré (40 %), Darou Mboumbaye (80 %). Si les modifications du lac Wouye et Tanma ont entrainé la perte progressive de leur valeur naturelle et des activités maraichères, les sites de Taré et de Darou Mboumbaye sont, en revanche, menacés par la migration vers le sud de la brèche ouverte sur la Langue de Barbarie. Dans ce contexte, la maitrise des modifications environnementales et de l’irrigation constitue les premiers facteurs d’amélioration de la production maraichère.   The area covered by the Niayes is one of the most fertile areas of the country. It is currently undergoing a process of degradation of the production systems of which the salinisation of the water table is the dominant factor. The purpose of this contribution is to analyze the salinization of groundwater and soils in the Niayes and particularly in the various study sites including Lake Wouye, Lake Tanma, the villages of Taré and Darou Mboumbaye. The methodology deployed, mainly based on sampling and laboratory analysis, made it possible to measure the salinity of the soils and groundwater of the quaternary sands table in 2010 and 2018. The results show a gradual degradation of irrigation water and a low salinity in the absorbent complex. Consequently, almost all of the land is abandoned in the sites studied because of alkalinization but above all the salinization of groundwater which constitutes the main source of irrigation. A number of market gardeners have lost a good part of their land (Lake Wouye 60 %, Lake Tanma 50 %, Taré 40 %, Darou Mboumbaye 80 %). If the modifications of Lake Wouye and Tanma have led to the gradual loss of their natural value and market gardening activities, the sites of Taré and Darou Mboumbaye are, on the other hand, threatened by the migration to the south of the breach opened on the Langue de Barbarie. Therefore, controlling irrigation is the first factor in improving market gardening production

Les Niayes du Littoral Nord du Senegal: Processus de Mise en Place, Salinisation des eaux Souterranies et des Sols

L’espace couvert par les Niayes fait partie des secteurs les plus fertiles du pays. Il subit actuellement un processus de dégradation des systèmes de production dont la salinisation de la nappe constitue le facteur dominant. L’objet de cette contribution est d’analyser la salinisation des eaux souterraines et des sols dans les Niayes et particulièrement dans les différents sites d’étude notamment le lac Wouye, le lac Tanma, les villages de Taré et de Darou Mboumbaye. La méthodologie déployée est essentiellement basée sur le prélèvement et l’analyse au laboratoire. Elle a permis de mesurer la salinité des sols et des eaux souterraines de la nappe des sables quaternaires en 2010 et 2018. Ainsi, les résultats démontrent une dégradation progressive des eaux d’irrigation et une faible salinité dans le complexe absorbant. Par conséquent, la quasi-totalité des terres est abandonnée dans les sites étudiés à cause de l’alcalinisation mais surtout la salinisation des eaux souterraines qui constitue la principale source d’irrigation. Ainsi, un nombre important de maraîchers a perdu une bonne partie des terres agricoles : lac Wouye (60 %), lac Tanma (50 %), Taré (40 %), Darou Mboumbaye (80 %). Si les modifications du lac Wouye et Tanma ont entrainé la perte progressive de leur valeur naturelle et des activités maraichères, les sites de Taré et de Darou Mboumbaye sont, en revanche, menacés par la migration vers le sud de la brèche ouverte sur la Langue de Barbarie. Dans ce contexte, la maitrise des modifications environnementales et de l’irrigation constitue les premiers facteurs d’amélioration de la production maraichère.   The area covered by the Niayes is one of the most fertile areas of the country. It is currently undergoing a process of degradation of the production systems of which the salinisation of the water table is the dominant factor. The purpose of this contribution is to analyze the salinization of groundwater and soils in the Niayes and particularly in the various study sites including Lake Wouye, Lake Tanma, the villages of Taré and Darou Mboumbaye. The methodology deployed, mainly based on sampling and laboratory analysis, made it possible to measure the salinity of the soils and groundwater of the quaternary sands table in 2010 and 2018. The results show a gradual degradation of irrigation water and a low salinity in the absorbent complex. Consequently, almost all of the land is abandoned in the sites studied because of alkalinization but above all the salinization of groundwater which constitutes the main source of irrigation. A number of market gardeners have lost a good part of their land (Lake Wouye 60 %, Lake Tanma 50 %, Taré 40 %, Darou Mboumbaye 80 %). If the modifications of Lake Wouye and Tanma have led to the gradual loss of their natural value and market gardening activities, the sites of Taré and Darou Mboumbaye are, on the other hand, threatened by the migration to the south of the breach opened on the Langue de Barbarie. Therefore, controlling irrigation is the first factor in improving market gardening production

Application of weather prediction models for hazard mitigation planning: a case study of heavy off-season rains in Senegal

Heavy off-season rains in the tropics pose significant natural hazards largely because they are unexpected and the popular infrastructure is ill-prepared. One such event was observed from January 9 to 11, 2002 in Senegal (14.00° N, 14.00°W), West Africa. This tropical country is characterized by a long dry season from November to April or May. During this period, although the rain-bearing monsoonal flow does not reach Senegal, the region can occasionally experience off-season rains. We conducted a numerical simulation of the January 9-11, 2002 heavy off-season rain using the Fifth-Generation NCAR/Pennsylvania State University Mesoscale Model (MM5) and the Weather Research and Forecasting (WRF) model. The objective was to delineate the meteorological set-up that led to the heavy rains and flooding. A secondary objective was to test the model's performance in Senegal using relatively simpler (default) model configurations and local/regional observations. The model simulations for both MM5 and WRF agree satisfactorily with the observations, particularly as regards the wind patterns, the intensification of the rainfall, and the associated drop in temperatures. This situation provided the environment for heavy rainfall accompanied by a cold wave. The results suggest that off-the-shelf weather forecast models can be applied with relatively simple physical options and modest computational resources to simulate local impacts of severe weather episodes. In addition, these models could become part of regional hazard mitigation planning and infrastructure

Quality of hydro-alcoholic products used in Senegal: pilot study

Antisepsis and disinfection have always played an important role in the fight against infectious diseases. The use of these products has been effective in breaking the chain of transmission of microorganisms. Today, with the advent of COVID-19, the main recommendations are, among other things, physical distance and the use of antiseptic products, including hydro-alcoholic products. In Senegal, with poor regulations on the acquisition and distribution of antiseptics and disinfectants, this situation has led to a proliferation of antiseptics and disinfectants on the national market. this work aimed to study the quality of hydroalcoholic products found in the trade. We evaluated ten samples of hydro-alcohol products collected during the month of March 2020. Physical and microbiological controls were performed at the National Drug Control Laboratory. The alcohol content of the samples ranged from 63 to 85% and were consistent with WHO recommendations except for samples E3 and E5. The pH values varied between 4.02 and 6.64 and the densities of the hydro-alcoholic gel samples ranged from 0.84 to 0.92 g/cm3; E2, E4, E5, E6 samples had densities greater than 0.89 g/cm3. The samples of hydro-alcoholic products all conformed to the sterility test and no microbiological contamination was observed. Antimicrobial activities of the hydro-alcoholic samples tested ranged from 58.3 to 100% with two samples showing no activity (E2 and E5). In view of the results of this study, it would be relevant to expand and deepen investigations by a significant increase in the number of samples and by carrying out as complete an analysis as possible

Impact of Climate Change on Corn Yields in Alabama

Abstract The study used calibrated Crop Environment Resource Synthesis (CERES) maize (corn) model to simulate maize (corn) physiological growth processes and yields under 2045 and 2075 projected climate change scenarios for six representative counties in Alabama. The future climatologies for two emission scenarios Representative Concentration Pathway (RCP) 4.5 (medium) and RCP 8.5 (high) were developed based on the IPSL-CM5A-MR high resolution climate model. Average yield decreases of 19.5% and 37.3% were, respectively, projected under RCP 4.5 and RCP 8.5 for 2045, and average yield decreases of 32.5% and 77.8% were, respectively, projected under RCP 4.5 and RCP 8.5 for 2075. These yield decreases were largely influenced by increasing temperatures as evidenced by the shortening of various development stages such as anthesis and maturity, which are important determinants of the final grain yield and number. Corn production in Autauga County was projected to be highly vulnerable to climate change, while production in Limestone County was least vulnerable. Corn crops in Alabama appear to be sensitive to climate change and will require adaptation strategies. Keywords: Climate Change, CERES-Maize model, General Circulation Model (GCM), Representative Concentration Pathway (RCP) emission scenarios

Le pneumothorax spontané comme une manifestation évolutive de la polyarthrite rhumatoide: à propos d’une observation clinique et revue de la litterature

La polyarthrite rhumatoïde est une maladie systémique inflammatoire caractérisée par une destruction des synoviales articulaires et des lésions systémiques extra articulaires. Les nodules pulmonaires font partie de ces dernières. Leur évolution peut aboutir à un pneumothorax spontané. Nous rapportons le cas d'un adulte jeune au long passé de polyarthrite rhumatoïde qui a présenté deux épisodes de pneumothorax spontané. Il était admis dans notre service, en urgence, pour un pneumothorax droit spontané et massif sur terrain de polyarthrite rhumatoïde au stade de déformation. Il était sous méthotrexate. La radiographie standard du thorax et la tomodensitométrie montraient un décollement pleural complet droit, des nodules et des images excavées sur les deux champs pulmonaires. Il a bénéficié d'un drainage thoracique aspiratif permettant une bonne ré-expansion pulmonaire. Le pneumothorax spontané constitue une manifestation rare des lésions pulmonaire de la polyarthrite rhumatoïde. Il s'agit le plus souvent d'une manifestation évolutive de la maladie mais aussi une circonstance de découverte de cette dernière. L'implication des immunosuppresseurs reste à être prouvée. Ainsi la polyarthrite rhumatoïde doit être considérée dans la recherche étiologique d'un pneumothorax spontané.Pan African Medical Journal 2015; 2

Unresolved issues with the assessment of multidecadal global land surface temperature trends

This paper documents various unresolved issues in using surface temperature trends as a metric for assessing global and regional climate change. A series of examples ranging from errors caused by temperature measurements at a monitoring station to the undocumented biases in the regionally and globally averaged time series are provided. The issues are poorly understood or documented and relate to micrometeorological impacts due to warm bias in nighttime minimum temperatures, poor siting of the instrumentation, effect of winds as well as surface atmospheric water vapor content on temperature trends, the quantification of uncertainties in the homogenization of surface temperature data, and the influence of land use/land cover (LULC) change on surface temperature trends. Because of the issues presented in this paper related to the analysis of multidecadal surface temperature we recommend that greater, more complete documentation and quantification of these issues be required for all observation stations that are intended to be used in such assessments. This is necessary for confidence in the actual observations of surface temperature variability and long-term trends

Documentation of Uncertainties and Biases Associated with Surface Temperature Measurement Sites for Climate Change Assessment

© Copyright 2007 American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act September 2010 Page 2 or that satisfies the conditions specified in Section 108 of the U.S. Copyright Act (17 USC §108, as revised by P.L. 94-553) does not require the AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a web site or in a searchable database, or other uses of this material, except as exempted by the above statement, requires written permission or a license from the AMS. Additional details are provided in the AMS Copyright Policy, available on the AMS Web site located at (https://www.ametsoc.org/) or from the AMS at 617-227-2425 or [email protected] objective of this research is to determine whether poorly sited long-term surface temperature monitoring sites have been adjusted in order to provide spatially representative independent data for use in regional and global surface temperature analyses. We present detailed analyses that demonstrate the lack of independence of the poorly sited data when they are adjusted using the homogenization procedures employed in past studies, as well as discuss the uncertainties associated with undocumented station moves. We use simulation and mathematics to determine the effect of trend on station adjustments and the associated effect of trend in the reference series on the trend of the adjusted station. We also compare data before and after adjustment to the reanalysis data, and we discuss the effect of land use changes on the uncertainty of measurement. A major conclusion of our analysis is that there are large uncertainties associated with the surface temperature trends from the poorly sited stations. Moreover, rather than providing additional independent information, the use of the data from poorly sited stations provides a false sense of confidence in the robustness of the surface temperature trend assessments.Department of Energy National Science Foundation National Aeronautics and Space Administration United States Geological Survey Mary K. Rice Foundatio