Recursos de colección

Aquatic Commons (37.154 recursos)

The Aquatic Commons is a thematic digital repository covering the natural marine, estuarine /brackish and fresh water environments . It includes all aspects of the science, technology, management and conservation of these environments, their organisms and resources, and the economic, sociological and legal aspects.

Subject = Atmospheric Sciences

Mostrando recursos 1 - 20 de 378

  1. Assessing recent warming using instrumentally homogeneous sea surface temperature records

    Hausfather, Zeke; Cowtan, Kevin; Clarke, David C.; Jacobs, Peter; Richardson, Mark; Rohde, Robert
    Sea surface temperature (SST) records are subject to potential biases due to changing instrumentation and measurement practices. Significant differences exist between commonly used composite SST reconstructions from the National Oceanic and Atmospheric Administration’s Extended Reconstruction Sea Surface Temperature (ERSST), the Hadley Centre SST data set (HadSST3), and the Japanese Meteorological Agency’s Centennial Observation-Based Estimates of SSTs (COBE-SST) from 2003 to the present. The update from ERSST version 3b to version 4 resulted in an increase in the operational SST trend estimate during the last 19 years from 0.07° to 0.12°C per decade, indicating a higher rate of warming in recent years. We show that ERSST version...

  2. On the effect of Arabian Sea and Indian Ocean sea surface temperature anomaly on the monsoon rainfall of south-east of Iran

    Malahi, Somayeh
    Southeast region of the country has hot and dry weather which causes to happen heavy rainfall in short time period of warm seasons and to occur river flooding. These precipitations are influenced by monsoon system of India ocean. In these thesis, It was tried to evaluate the relation between thermal anomaly of sea surface in India ocean and Arab sea which effects on southeast monsoon precipitations of Iran, For evaluation of this happening in southeast, data were collected from 7 synoptic observation stations of Bandar Abbas, Minab, Kerman , Bam, Chabahar, Iranshahr, Zahedan and 17 rain gauge stations during June...

  3. Seasonal changes of heat and moisture fluxes from the Caspian Sea surface and its effect on synoptic systems with heavy rainfalls in southern shores of the sea during 2005-2010

    Barandoust, Khalil
    Caspian Sea with its unique characteristics is a significant source to supply required heat and moisture for passing weather systems over the north of Iran. Investigation of heat and moisture fluxes in the region and their effects on these systems that could lead to floods and major financial and human losses is essential in weather forecasting. Nowadays by improvement of numerical weather and climate prediction models and the increasing need to more accurate forecasting of heavy rainfall, the evaluation and verification of these models has been become much more important. In this study we have used the WRF model as...

  4. La forme des récifs coralliens et le régime des vents alternants

    Krempf, A.
    This paper deals with the development of crescent-shaped reefs in the China Sea under control of northwest and southeast monsoon winds alternating in direction seasonally. The transport of sediment derived from windward side to leeward around reef ends has been studied. A description of the analogy of these large structures with individual coral colonies developing in similar manner under current action as micro atolls has given.

  5. Investigation into the meteorological aspects of the variations in the level of Lake Victoria

    Mörth, H.T.
    The level of Lake Victoria has, since 1961, reached a height which caused serious flood damage. Already the financial implications are considerable for Kenya, Tanzania and Uganda. If further rises can be anticipated, expenditure on flood control measures to the tune of several million pounds sterling must be envisaged. If such rises should lead to uncontrolled discharge at the Owen Falls Dam site because of overshooting, downstream districts of Uganda and the Sudan may be seriously flooded. All this merits a thorough study, and any indication of the future behaviour of lake levels, even when associated with a low probability,...

  6. An instance of cyclonic upwelling in the southern offshore waters of Lake Victoria

    Kitaka, G.E.B.
    Evidence is presented that cyclonic upwelling took place in the southern offshore waters of Lake Victoria on the 22nd to the 23rd March, 1969. Before this, the main upper thermocline was tilted downwards in the leeward northern half of the lake in response to the accumulation of epilimnetic water. Cyclonic upwelling might be quite common because of the frequent occurrence of storms on Lake Victoria, and probably on other tropical African lakes. However, to my knowledge, it has never been reported from any lake.

  7. Feasibility study: the methods and approaches to implementing a SEREAD teacher training programme in BOBLME countries

    Wicks, L.
    Objectives included a desk-top feasibility study to explore opportunities to adapt the Scientific Educational Resources and Experience Associated with the Deployment of Argo profiling floats in the South Pacific Ocean (SEREAD) to BOBLME country schools.The programme included teacher resources on climate change and facilitating interactions between scientists, students and teachers.

  8. Meeting on BOBLME engagement in the International Indian Ocean Expedition 50th anniversary initiative (IIOE-2), Bangkok, Thailand, 17-18 March, 2015

    Wicks, L.; D'Adamo, N.
    Objectives included; a contribution to understanding large-scale processes affecting the Bay of Bengal Large Marine Ecosystem Project (BOBLME) and it's living resources; and to align with International Indian Ocean Expedition (IIOE-2) (2015-2020) which will extensively explore and study the Indian Ocean to improve understanding of the ocean and coupled climate processes.

  9. Spreading of Persian Gulf water in the northwestern Arabian sea during the month of January

    Ali, A.; Syed, N.A.
    The presence of different water masses in the North Arabian Sea continues to remain of interest to scientists and researchers. Focus on these water masses is due to the unique monsoonal reversal features of the Arabian Sea. The encroachment of Persian Gulf water into the Arabian Sea has been acknowledged and traced. This paper presents the results of an investigation on the spreading patterns of Persian Gulf water in the northwestern Arabian Sea. The study incorporated two different techniques: the core-layer method and the constant sigma-theta surface method on data collected during the North Arabian Sea Environment and Ecosystem Research...

  10. Estimates of the surface heat fluxes in Antarctic waters

    Ahmed, F.; Sultan, S.A.R.; Moammar, M.O.
    The authors have attempted to compute the heat balance terms on the basis of formulas by Budyoko (1974). Some of the meteorological and oceanographic data were collected during the Trans Antarctic Expedition (1989-90). These data were supplemented by the data (1956-1988) made available by the national climatic center of NOAA (National Oceanic and Atmospheric Administration). Monthly means of sea surface temperature in Antarctic waters and meteorological data at a station (77°51'S; 166°39'E) 33m above sea level are given.

  11. Relationship between El Nino and summer monsoon rainfall over Pakistan

    Mahmood, A.; Khan, T.M.A.; Faisal, N.
    The present paper deals with the influence of El Nino event on the summer monsoon rainfall over Pakistan. The correlation between monthly rainfall of summer monsoon season and bi-Monthly Multivariate ENSO Index (MEI) has been calculated to see the influence of El Nino on the summer monsoon rainfall. MEI is bimonthly ENSO Index pertaining to the period from first week of previous month to first week of the month under consideration. While study the correlation's with the ENSO events out side the Pacific Ocean MEI is more appropriate than other indices like Southern Oscillation Index (SOI) as MEI integrates complete...

  12. Heat budget studies of the north Arabian Sea during summer and winter seasons, 1992

    Ali Khan, Tariq Masood; De Las Alas, J.G.; Estoque, Mariano A.; Rizvi, S.H. Niaz
    In this study heat budget components and momentum flux for August and January 1992 over the north Arabian Sea are computed. The marine meteorological data measured on board during the cruises of PAK-US joint project (NASEER) are used for the computation. Significant differences were found in the heat budget components as well as in the momentum flux during different monsoon periods over the north Arabian Sea. The latent heat flux was always positive and attributed to the large vapour pressure gradient. The computed moisture and latent heat fluxes in January were higher than August The highest value of latent heat...

  13. Vertical temperature structure of 250 m. water layer around Sri Lanka at the tail-end of the north-east monsoon

    Samarasinghe, J.R. de S.
    Data collected during cruises of the Hoyo Maru in Jan-Mar 1975 are analysed. Data is tabulated to show vertical temp profile, surface water temp and temp gradient. Each of these features is discussed. Thermoclines are shown to be established off the coast of India, their depth varying according to time of year. Upwelling off the Cochin coast is discussed. This occurs during Oct-Nov. Surface temp is considerably influenced by the north-east monsoon. The 'clockwise current' (or 'transparent current) characterised by high salinity, high transparency, and rich nutrient conchs, and which prevails in Jan-May brings oceanic water into the Bay of...

  14. Community visioning and action plans: Tonle Sap hub

    Oeur, I.; Dane, S.; Sopheakdey, S.
    The process of rolling out the CGIAR Research Program on Aquatic Agricultural Systems (AAS) in 12 target villages in the Tonle Sap region in Cambodia throughout 2013 involved several important tasks at different stages. This report covers one of those tasks: the Community Life Competence Process (CLCP), commonly referred to by stakeholders as "visioning". It has two main objectives: (1) to document the community visioning process, including the development of a community action plan and NGO work plan to monitor progress; and (2) to document village and network profiles of key community stakeholders at the village level.

  15. Atrapando C02 en el mar patagónico

    Bianchi, A.A.; Osiroff, A.P.; Balestrini, C.F.; Piola, A.R.; Perlender, H.I.
    El océano captura una gran proporción del anhídrido carbónico atmosférico. En este artículo de divulgación científica se presenta el caso del mar patagónico (océano Atlántico sudoccidental, Argentina). Se incluye información sobre CO2 y el cambio climático; la importancia del océano en el ciclo del carbono; el flujo mar-atmósfera de CO2; la importancia de los mares costeros, entre otros, y otras lecturas sugeridas relativas a la temática.

  16. Commodity and product identification for value chain analysis.

    Navy, H.; Johnstone, R.
    This commodity and product identification research was undertaken in the context of the CGIAR Research Program on Aquatic Agricultural Systems (AAS). AAS seeks to reduce poverty and improve food security for the millions of small-scale fishers and farmers who depend on the world’s floodplains, deltas and coasts. The objective of this research is to strengthen the capacity of AAS to undertake value chain studies with high potential impact on smallholders. The capacity-building aspect of this research was focused on the process of commodity and product identification for value chain analysis. Its scope was limited to fish and other aquatic animals...

  17. Comparisons of open boundary conditions in a barotropic model of the northern Arabian Sea

    Khan, T.M.A.; De Las Alas, J.G.; Estoque, M.A.
    These simulations are focused on the sensitivity of the barotropic ocean non-linear model to the various open boundary conditions (OBCs). Different OBCs from gradient to radiation condition are examined to determine the best result and help to choose the most appropriate OBCs. Since the interior points are changing with time both implicit and explicit forms are applied. The simulations showed that the interior flow is sensitive to changes in the OBCs and the results are highly dependent on the bathymetry of the area. When a constant depth (100m) is used, the circulation pattern with all OBCs is same. The best...

  18. Nature of the rain spectrum at a low latitude coastal station

    Rajan, C.K.; Bindu, G.
    The internal structure of rain falls in terms of rain rate during various instances of time can be determined by measuring rain amounts received during very short intervals of time. A system that can record the intensity of rain fall at every minute has been used for this study.

  19. Application of a wind-driven barotropic model to simulate the seasonal circulation of the northern Arabian Sea

    Khan, T.M.A.; De Las Alas, J.G.; Estoque, M.A.
    A two dimensional numerical barotropic model based on the depth-integrated equations is presented here. Sensitivity of the model is analyzed by using wind stresses of different months. Real wind data and actual bathymetry are used as an input to obtain the circulation patterns of the northern Arabian Sea during specific seasons. However, the model is also tested with constant depth for comparison. A number of numerical simulations are performed to study the combined effects of wind stress, bathymetry and basin geometry. Since the goal of this study is to simulate the circulation of the northern Arabian sea in accordance with...

  20. Role of rainfall in the breeding of Labeo rohita (Ham.), Cirrhinus mrigala (Ham.), Catla catla (Ham.), at Damdama (Haryana), a semi-arid zone

    Jain, Atul K.; Singh, R.; Alkesh, D.; Mitra, S.D.
    The role of several environmental factors on the breeding and hatching of fish has been studied by many earlier investigators. Perfection in the hypophysation technique has helped to some extent in by-passing the environmental variables such as temperature, light and rain. With the use of a modern fish hatchery, it is possible to attain maximum success in breeding and hatching, even without rains; reference is given to studies carried out regarding the role of rainfall in the breeding of Labeo rohita, Cirrhinus mrigala, Catla catla.

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