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104-516: In the beginning, the project intended to observe, comprehend and model the Earth's water cycle . The experiment also observes how much energy the Earth receives, and studies how much of that energy reaches the surfaces of the Earth and how that energy is transformed. Sunlight 's energy evaporates water to produce clouds and rain and dries out land masses after rain. Rain that falls on land becomes

208-412: A parametric model , the probability distribution function has variable parameters, such as the mean and variance in a normal distribution , or the coefficients for the various exponents of the independent variable in linear regression . A nonparametric model has a distribution function without parameters, such as in bootstrapping , and is only loosely confined by assumptions. Model selection

312-453: A certain purpose in mind, hence the core semantic concepts are predefined in a so-called meta model. This enables a pragmatic modelling but reduces the flexibility, as only the predefined semantic concepts can be used. Samples are flow charts for process behaviour or organisational structure for tree behaviour. Semantic models are more flexible and open, and therefore more difficult to model. Potentially any semantic concept can be defined, hence

416-407: A concept model operational semantic can be built-in, like the processing of a sequence, whereas a semantic model needs explicit semantic definition of the sequence. The decision if a concept model or a semantic model is used, depends therefore on the "object under survey", the intended goal, the necessary flexibility as well as how the model is interpreted. In case of human-interpretation there may be

520-452: A conceptual model is developed using some form of conceptual modeling technique. That technique will utilize a conceptual modeling language that determines the rules for how the model is arrived at. Understanding the capabilities of the specific language used is inherent to properly evaluating a conceptual modeling technique, as the language reflects the techniques descriptive ability. Also, the conceptual modeling language will directly influence

624-473: A family tree of the Greek Gods, in these cases it would be used to model concepts. A domain model is a type of conceptual model used to depict the structural elements and their conceptual constraints within a domain of interest (sometimes called the problem domain ). A domain model includes the various entities, their attributes and relationships, plus the constraints governing the conceptual integrity of

728-610: A focus on graphical concept models, in case of machine interpretation there may be the focus on semantic models. An epistemological model is a type of conceptual model whose proposed scope is the known and the knowable, and the believed and the believable. In logic , a model is a type of interpretation under which a particular statement is true. Logical models can be broadly divided into ones which only attempt to represent concepts, such as mathematical models; and ones which attempt to represent physical objects, and factual relationships, among which are scientific models. Model theory

832-456: A function/ active event must be executed. Depending on the process flow, the function has the ability to transform event states or link to other event driven process chains. Other elements exist within an EPC, all of which work together to define how and by what rules the system operates. The EPC technique can be applied to business practices such as resource planning, process improvement, and logistics. The dynamic systems development method uses

936-411: A given model involving a variety of abstract structures. A more comprehensive type of mathematical model uses a linguistic version of category theory to model a given situation. Akin to entity-relationship models , custom categories or sketches can be directly translated into database schemas . The difference is that logic is replaced by category theory, which brings powerful theorems to bear on

1040-434: A metaphysical model intends to represent reality in the broadest possible way. This is to say that it explains the answers to fundamental questions such as whether matter and mind are one or two substances ; or whether or not humans have free will . Conceptual Models and semantic models have many similarities, however the way they are presented, the level of flexibility and the use are different. Conceptual models have

1144-452: A multifold increase of moist air flow from the Gulf of Mexico to the flooded regions was a major factor in excessive rainfall. The Global Land/Atmosphere System Study (GLASS) gave GEWEX investigators the ability to observe soil wetness over much of the world's surface by correlating observations on the ground with information obtained by satellites. While the ability to show cause is important,

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1248-621: A renewed effort for better data and with more observation satellites, the GPCP, hopes to gain insights to rainfall variation on 'weather'-scale, or 4-hour periods to daily time scales. The Precipitation Assessment Group was assigned by the panel to evaluate data on precipitation emphasizing data in the Global Precipitation Climatology Project (GPCP) product (GRP project). The GRP prepares to assimilate data from GPCP diurnal variation data for better estimation of

1352-451: A single thing (e.g. the Statue of Liberty ), whole classes of things (e.g. the electron ), and even very vast domains of subject matter such as the physical universe. The variety and scope of conceptual models is due to the variety of purposes had by the people using them. Conceptual modeling is the activity of formally describing some aspects of the physical and social world around us for

1456-526: A sink for CO 2 that is adsorbed at the polar regions, as this builds into the Pacific the upwelling and warming of water can bring CO 2 -rich waters trapped in the cold pressurized bottom layers to the surface. Local increases of CO 2 occur which allow more heat-trapping; the La-Nina may be mild or aborted early in the process. However, if the return of the thermocline has enough momentum it could propel

1560-580: A specific process called JEFFF to conceptually model a systems life cycle. JEFFF is intended to focus more on the higher level development planning that precedes a project's initialization. The JAD process calls for a series of workshops in which the participants work to identify, define, and generally map a successful project from conception to completion. This method has been found to not work well for large scale applications, however smaller applications usually report some net gain in efficiency. Also known as Petri nets , this conceptual modeling technique allows

1664-472: A stalling of long-term cycles is believed to be a factor in the Dryas period, a warming interrupted by surface impacts of extraterrestrial origin may have occurred over hundreds of years. But the anthropogenic greenhouse effects and changing insolation patterns may have unpredictable long-term effects. Reductions of glacial ice on land masses can cause isostatic rebounds and may affect earthquakes and volcanism over

1768-431: A statistical model of customer behavior is a model that is conceptual (because behavior is physical), but a statistical model of customer satisfaction is a model of a concept (because satisfaction is a mental not a physical event). In economics , a model is a theoretical construct that represents economic processes by a set of variables and a set of logical and/or quantitative relationships between them. The economic model

1872-596: A strong La-Nina event that last for a few years. However, rapid cooling in the Arctic can allow for more CO 2 trapping and offset release of CO 2 during La-Nina in a specific area. The Pacific Decadal Anomaly (PDA See image) may influence the source, direction or momentum of rise of the cold water component of the thermocline. The extent and duration of the PDA are yet unpredictable, and its modulating effects on El-Nino/La-Nina patterns can only be speculated. These unknowns affect

1976-735: A system to be constructed with elements that can be described by direct mathematical means. The petri net, because of its nondeterministic execution properties and well defined mathematical theory, is a useful technique for modeling concurrent system behavior , i.e. simultaneous process executions. State transition modeling makes use of state transition diagrams to describe system behavior. These state transition diagrams use distinct states to define system behavior and changes. Most current modeling tools contain some kind of ability to represent state transition modeling. The use of state transition models can be most easily recognized as logic state diagrams and directed graphs for finite-state machines . Because

2080-472: A system, often a relational database, and its requirements in a top-down fashion. Diagrams created by this process are called entity-relationship diagrams, ER diagrams, or ERDs. Entity–relationship models have had wide application in the building of information systems intended to support activities involving objects and events in the real world. In these cases they are models that are conceptual. However, this modeling method can be used to build computer games or

2184-459: A system. DFM is a fairly simple technique; however, like many conceptual modeling techniques, it is possible to construct higher and lower level representative diagrams. The data flow diagram usually does not convey complex system details such as parallel development considerations or timing information, but rather works to bring the major system functions into context. Data flow modeling is a central technique used in systems development that utilizes

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2288-435: A technique that would allow relevant information to be presented. The presentation method for selection purposes would focus on the technique's ability to represent the model at the intended level of depth and detail. The characteristics of the model's users or participants is an important aspect to consider. A participant's background and experience should coincide with the conceptual model's complexity, else misrepresentation of

2392-511: A wide range. Rising sea levels can also affect patterns, and was seen in Indonesia, simply drilling a gas well in the wrong place may have touched off a mud volcano and there are some signs that this may precede a new caldera formation for a volcano. Over the very long term, the change in temperature of the Earth's crust on geothermal and volcanic processes is unknown. How this plays into climate-forcing events with magnitudes that are unpredictable

2496-487: Is a conceptual modeling technique which is mainly used to systematically improve business process flows. Like most conceptual modeling techniques, the event driven process chain consists of entities/elements and functions that allow relationships to be developed and processed. More specifically, the EPC is made up of events which define what state a process is in or the rules by which it operates. In order to progress through events,

2600-419: Is a graphical representation of modal logic in which modal operators are used to distinguish statement about concepts from statements about real world objects and events. In software engineering, an entity–relationship model (ERM) is an abstract and conceptual representation of data. Entity–relationship modeling is a database modeling method, used to produce a type of conceptual schema or semantic data model of

2704-680: Is a more recent addition to GEWEX. The study is tasked with understanding the physical properties of the atmospheric boundary layers for better models which include representation of boundary layers. GEWEX Cloud System Study ( GCSS ) task is to individualize modelling for different types of cloud systems. GCSS identifies 5 types of cloud systems:boundary layer, cirrus, extra tropical layer, precipitating convective, and polar. These cloud systems are generally too small to be rationalized in large scale climate modelling, this results in inadequate development of equations resulting in greater statistical uncertainty in results. In order to rationalize these processes,

2808-432: Is a process of study which observes the contribution of irregular events, such a volcano eruption, greenhouse warming, solar variation, fluctuations in the Earth's orbit, long-term variation in the oceans circulation. The GMPP exploits these natural perturbations to test models developed that should predict what happens to global energy and water budgets with the perturbations. GEWEX Atmospheric Boundary Layer Study ( GABLS )

2912-484: Is a sharp temperature drop at depth; it varies during the year, with location, and over long periods of time. As the thermocline depth increases El-Nino events are more likely; however, during the peak of the event energy is dissipated and the thermocline decreases depth, possibly to below normal levels so the a strong La-Nina event can results. The world's oceans, particularly the depths of the Atlantic, are believed to be

3016-423: Is a simplified framework designed to illustrate complex processes, often but not always using mathematical techniques. Frequently, economic models use structural parameters. Structural parameters are underlying parameters in a model or class of models. A model may have various parameters and those parameters may change to create various properties. A system model is the conceptual model that describes and represents

3120-445: Is a statistical method for selecting a distribution function within a class of them; e.g., in linear regression where the dependent variable is a polynomial of the independent variable with parametric coefficients, model selection is selecting the highest exponent, and may be done with nonparametric means, such as with cross validation . In statistics there can be models of mental events as well as models of physical events. For example,

3224-558: Is an international cooperation it can utilize information from existing and planned satellites. The CEOP project has a number of energy budget and water cycle objectives. First is to produce more consistent research with better error definitions. Second is to better determine how energy flux and water cycles involve in feedback mechanisms. Third is to the predictability of important variables and improved parametric analysis to better model these processes. Fourth, to collaborate with other hydrological science projects to create tools for assessing

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3328-565: Is fundamentally a study of concepts, the meaning that thinking beings give to various elements of their experience. The value of a conceptual model is usually directly proportional to how well it corresponds to a past, present, future, actual or potential state of affairs. A concept model (a model of a concept) is quite different because in order to be a good model it need not have this real world correspondence. In artificial intelligence, conceptual models and conceptual graphs are used for building expert systems and knowledge-based systems ; here

3432-475: Is large relative to possible trends . The number of ground sensing stations (currently around 40) in the BSRN is rather limited for global observation this affected the measurement of aerosols which are regionally dominant. The best measurements of aerosol pollution are obtained when cloud types are identified properly by satellite observation, therefore better cloud sensing strategies and models are needed to provide

3536-606: Is linked to other WCRP projects such as Stratospheric Processes and their Role in Climate (SPARC) Project, and the Climate and Cryosphere Project through WCRP. and thus shares information and goals with other WCRP projects. The goal becomes more important with the newer WCRP project, the Coordinated Observation and Prediction of the Earth System . Aside from fluctuations of solar radiation, the sunlight that

3640-611: Is now done by the International GEWEX Project Office (IGPO). IGPO oversees major initiatives and coordinates between national projects in an effort to bring about communication between researchers. IGPO claims to support communication exchange between 2000 scientist and is the instrument for publication of major reports. The Scientific Steering Group organizes the projects and assigns them to panels , which oversee progress and provide critique. The Coordinated Energy and Water Cycle Observations Project (CEOP)

3744-411: Is now the core project of WCRP. Predicting weather change requires accurate data that is collected over many years, and the application of models . GEWEX was conceived to respond to the need for observations of the Earth's radiation budget and clouds. Many preexisting techniques were limited to observations taken from land and populated areas. This ignored the large amount of weather that occurs over

3848-452: Is radiated back into space. GPCP task was to estimate precipitation using satellites that were global including places where people were not present to take measurements. Secondarily the project was tasked with studying regional precipitation on seasonal to between year time scales. As the study period of the project increased past 25 years a third objective was added analyze long-term variation, such as that caused by global warming . Also, in

3952-405: Is reflected, the earth or water where heat and light are radiated back into the atmosphere or space. When water is struck heated surface water can evaporate carrying energy back into space through cloud formation and rain. The SRB project measured these processes by measuring fluxes at the Earth's surface, top-of-atmosphere with shortwave (SW) and longwave (LW) radiation. At the onset of GEWEX there

4056-638: Is the inability to capture decadal rainfall events, events that frequently occur over a few hours. Therefore, more measurements documenting shorter time frames may provide essential data for almost continuous data set. Therefore, Phase II is mainly modelling with addition of more data as deemed lacking in Phase I. Many of the critiques above may be compensated for with better data requiring better models including insolation and changes in reflection. The problem with variation in ocean currents, particular with respect to thermocline depths requires more oceanography as part of

4160-593: Is the largest of the panel projects. There are several regional project areas most of these are now covered by CEOP For CEOP which survey the hydroclimate for southern African (AMMA), Baltic Sea area (BALTEX), North America (CPPA), Eastern Amazonia (LBA), La Plate Basin (LBB), Asia (MAHASRI), Australia (MDB), and Northern Eurasia (NEEPSI). In addition, CEOP coordinates the study of region types, such as cold, high altitude, monsoon, and semiarid climates and collects and formulates modelling on global, regional scale including land surface and surface hydrology modelling. Since GEWEX

4264-674: Is the study of (classes of) mathematical structures such as groups, fields, graphs, or even universes of set theory, using tools from mathematical logic. A system that gives meaning to the sentences of a formal language is called a model for the language. If a model for a language moreover satisfies a particular sentence or theory (set of sentences), it is called a model of the sentence or theory. Model theory has close ties to algebra and universal algebra. Mathematical models can take many forms, including but not limited to dynamical systems, statistical models, differential equations, or game theoretic models. These and other types of models can overlap, with

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4368-649: Is transformed by the Earth can vary greatly, some have concluded for instance, that ice-ages self-perpetuate once enough ice has accumulated in the polar regions to reflect enough radiation at high elevations to lower the global average temperature, whereas it takes an unusually warm period to reverse this state. Water usage by plants, herbivore activities can change albedo in the temperate and tropical zones. These trends in reflection are subject to change. Some have proposed extrapolating pre-GEWEX information using new information and measurements taken with pre-GEWEX technology. Natural fires, volcanism, and man-made aerosols can alter

4472-416: Is unknown. The critiques at GEWEX can only be thrust at current results, which have added much more information about climate modelling that have created critiques, the major thrust of modelling was originally intended to be part of Phase II which will, after 4 years, produce its results. One of the major critiques of GEWEX phase I was land-based measurements, which are now increasing. The other major critique

4576-440: Is unpredictable on seasonal scales. Through weather patterns such as droughts and higher rainfall these cycles impact ecosystems and human activities. GEWEX is designed to collect a much greater amount of data, and see if better models of that data can forecast weather and climate change into the future. GEWEX is organized into several structures. As GEWEX was conceived projects were organized by participating factions, this task

4680-578: The structured systems analysis and design method (SSADM). Entity–relationship modeling (ERM) is a conceptual modeling technique used primarily for software system representation. Entity-relationship diagrams, which are a product of executing the ERM technique, are normally used to represent database models and information systems. The main components of the diagram are the entities and relationships. The entities can represent independent functions, objects, or events. The relationships are responsible for relating

4784-754: The 'Hydrology Project' is a major instrument in GEWEX. This panel includes geographic study areas such as the Climate Prediction Program for the Americas operated by NOAA , but also examines several types of climate zones (e.g. high altitude and semi-arid). Another panel, the GEWEX Radiation Panel oversees the coordinated use of satellites and ground-based observation to better estimate energy and water fluxes. One recent result GEWEX's Radiation panel has assessed data on rainfall for

4888-493: The Earth's energy budget and water cycle, contribution of processes in climate feedback, causes of natural variability, predicting changes on seasonal or annual timescales, and how changes impact water resources. Phase II of is designed to be active models that have use to regional resource managers in real time. Some phases, such as the GAME (GEWEX Asia Monsoon Experiment) are already completed . GEWEX has become an umbrella program for

4992-567: The GEWEX study, these oscillations are an aspect of climate forcing, which allow testing of predictions and models. This modelling may be complicated by the fact that the North Atlantic Oscillation in switching state (see graph) as the effects of global warming are becoming more prominent. For example, 2006 and 2007 saw one of the most dramatic declines in Arctic Sea ice, a decline that was largely unpredicted and can shift

5096-499: The ability for climate modellers to predict and indicate climate-forcing models need to accurate a wider sampling of data to be predictive. There are also longer-term cycles, the mini ice-age that preceded the medieval warm period may have been a transition to an ice age, the last ice-age lasted from ~130,000 years ago until the onset of the Holocene. This ice-age may have been aborted by other factors including global warming. Such

5200-400: The affected variable content of their proposed framework by considering the focus of observation and the criterion for comparison. The focus of observation considers whether the conceptual modeling technique will create a "new product", or whether the technique will only bring about a more intimate understanding of the system being modeled. The criterion for comparison would weigh the ability of

5304-546: The amount of radiation reaching the Earth. There are oscillations in oceanic currents, such as El-Niño and North Atlantic Oscillation, which alter the parts of the Earth's ice mass and land water availability. The experiment takes a sampling of climate, with some trends lasting a million years, and as paleo-climatology shows, can abruptly change. Therefore, the ability to use data to predict change depends on factors that are measurable over periods of time, and factors that can affect global climate that abruptly appear can markedly alter

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5408-479: The analysts are concerned to represent expert opinion on what is true not their own ideas on what is true. Conceptual models range in type from the more concrete, such as the mental image of a familiar physical object, to the formal generality and abstractness of mathematical models which do not appear to the mind as an image. Conceptual models also range in terms of the scope of the subject matter that they are taken to represent. A model may, for instance, represent

5512-459: The authors specifically state that they are not intended to represent a state of affairs in the physical world. They are also used in information requirements analysis (IRA) which is a variant of SSM developed for information system design and software engineering. Logico-linguistic modeling is another variant of SSM that uses conceptual models. However, this method combines models of concepts with models of putative real world objects and events. It

5616-514: The center. The heat of the water under the storm drops. Cyclones demonstrate how much latent energy is stored in the world's oceans. Another example is the floods that hit the Midwest U.S. in 1993. The energy that drove moisture into the air occurred in the Gulf, and strong winds and lack of cooling in coastal regions permitted the moisture to travel 1000 miles until conditions were ripe for rain. As

5720-516: The clearest real-time data. Certain projects like GCIP allow have focused on continental scale observations provide better prediction for project areas; however, areas outside these project areas may lag in receiving forecasting improvements. Many of the deficiencies in Phase I are improvement areas within the objectives of Phase II of the project. Currently scientist use NASA Aqua's Advanced Microwave Scanning Radiometer (AMSR-E) to evaluation soil moisture from space. However, except for focused observations

5824-527: The coasts of some developing nations and extend hundreds of miles over surrounding oceans. Some have questioned whether this aerosol pollution is partly to blame for long-term drought in places like the African Sahel . One critique of the Build-up Phase data and predictions is that there needs to be better error descriptions. The global estimate of rainfall indicates that the confidence range

5928-403: The conceptual modeling method can sometimes be purposefully vague to account for a broad area of use, the actual application of concept modeling can become difficult. To alleviate this issue, and shed some light on what to consider when selecting an appropriate conceptual modeling technique, the framework proposed by Gemino and Wand will be discussed in the following text. However, before evaluating

6032-456: The conceptual modeling technique to be efficient or effective. A conceptual modeling technique that allows for development of a system model which takes all system variables into account at a high level may make the process of understanding the system functionality more efficient, but the technique lacks the necessary information to explain the internal processes, rendering the model less effective. When deciding which conceptual technique to use,

6136-562: The coordination of studies and experiments around the world. Reports from the phase I are still being produced and it will be some time before the results of the second phase are available. The experiment is still in progress. There are three panels in GEWEX: The Coordinated Energy and Water Cycle Observations Project (CEOP), GEWEX Radiation Panel (GRP), and GEWEX Modeling and Prediction Panel (GMPP). The Coordinated Energy and Water Cycle Observations Project ( CEOP )

6240-433: The data are most useful in determining rainfall. The research interest of GEWEX is to study fluxes of radiation at the Earth's surface, predict seasonal hydration levels of soils and develop accurate models of predicting energy and water budgets around the world. The project sets its goal as to improve, by an order of magnitude, the ability to model and therefore prediction hydration (rainfall and evaporation) patterns GEWEX

6344-514: The dataset analysis have the flaw of not having inaccurate measurements of drizzle and snow, and lack measurements in isolated places and over oceans. The rainfall maps show the greatest absolute rainfall error over the tropical oceans in regions with the highest estimated rainfall. The report self-critiques two aspects: the lack of polar-crossing satellites at the beginning of the study and the inability to correlate new information and older information (ground-based measurements). The noticeable trends in

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6448-486: The dataset were deemed insignificant with regard to issues like global warming, but some stand-out positive trends over the Indopacific region were notable (Bay of Bengal and Indochina) and negative trends over South Central Africa . The SRB project under NASA/GEWEX took global radiation measurements to determine radiative energy fluxes. The energy that comes from the sun strikes the atmosphere and scatters, clouds and

6552-500: The depth at which the system is capable of being represented, whether it be complex or simple. Building on some of their earlier work, Gemino and Wand acknowledge some main points to consider when studying the affecting factors: the content that the conceptual model must represent, the method in which the model will be presented, the characteristics of the model's users, and the conceptual model languages specific task. The conceptual model's content should be considered in order to select

6656-457: The different conditions (soil wetness, global patterns) that were permissive for weather anomalies are the focus of Phase I, gathering information and learning how to use satellite information better. One of the biggest impacts of the Aerosol analysis has been the demonstration of the fairly large impact of anthropogenic aerosols, smoke patterns, even daily ripples of aerosols can be observed off

6760-592: The distribution of aerosols, how they are formed, transformed and transported. The GEWEX cloud assessment was initiated by the GEWEX Radiation Panel (GRP) in 2005 to evaluate the reliability of available, global, long-term cloud data products, with a special emphasis on ISCCP. The GEWEX modelling and prediction panel ( GMPP ) is charged with the task of finding better ways to use the data by other projects and other agencies. It oversees GEWEX Atmospheric Boundary Layer Study (GABLS), GEWEX Cloud System Study (GCSS), and Global Land/Atmosphere System Study(GLASS). Climate forcing

6864-418: The effectiveness of a conceptual modeling technique for a particular application, an important concept must be understood; Comparing conceptual models by way of specifically focusing on their graphical or top level representations is shortsighted. Gemino and Wand make a good point when arguing that the emphasis should be placed on a conceptual modeling language when choosing an appropriate technique. In general,

6968-403: The enterprise process model is often referred to as the business process model . Process models are core concepts in the discipline of process engineering. Process models are: The same process model is used repeatedly for the development of many applications and thus, has many instantiations. One possible use of a process model is to prescribe how things must/should/could be done in contrast to

7072-429: The entities to one another. To form a system process, the relationships are combined with the entities and any attributes needed to further describe the process. Multiple diagramming conventions exist for this technique; IDEF1X , Bachman , and EXPRESS , to name a few. These conventions are just different ways of viewing and organizing the data to represent different system aspects. The event-driven process chain (EPC)

7176-421: The events will eventually take dominance, lack of precedents from the past study of similar confluences of events, as well as knowledge of the uncertainty of sensitive 'switches' in the oceanic/atmospheric switches may affect the ability to provide accurate models and predictions. In addition, sampling points may be spread to monitor leading indicators in one common scenario may be useless during an oscillation where

7280-418: The future. GEWEX is being implemented in phases. The first phase comprises information gathering, modelling, predictions, and advancement of observation techniques and is complete. The second phase addresses several scientific questions such as prediction capacity, changes in Earth's water cycle, and the impact on water resources. Phase I (1990–2002), also called the "Build-Up Phase", was designed to determine

7384-422: The global precipitation products. The result of 25 years of measurement the global average precipitation rate is 2.61 mm per/day (about 0.1 inch/day) with about 1% uncertainty. The finding suggests there is no significant variation in mean annual rainfall. Regional variation was separated from land and ocean and the land variation of received precipitation was greater than the ocean. Satellites used to train

7488-485: The heat of daytime, creating clouds. As the density of droplets in the clouds increase, the air can no longer support droplets and they fall as rain. More moist air can be drawn into clouds as energy is released, allowing the development of large thunderstorms. Prevailing winds are a factor in storm formation, particularly when changes occur. Tropical waves that develop in westerly flows around the Earth's semitropical and tropical region can organize into horizontal circles over

7592-422: The hydrological cycle and energy fluxes by means of global measurements of atmospheric and surface properties. GEWEX was also designed to model the global hydrological cycle and its impact on the atmosphere, oceans and land surfaces. Phase I processes were to develop the ability to predict the variations of global and regional hydrological processes & water resources, and their response to environmental change. It

7696-746: The impact on land surface parameters on the atmosphere. Changes in land as a result of natural and man-made activities results in the ability to alter the local climate and affect wind and cloud formation. The GEWEX project has been in existence for over 30 years, and while some climate oscillations are short, such as El-Nino, some climate oscillations last for decades, such as the North Atlantic Oscillation. Some have proposed extrapolating pre-GEWEX information using new information and measurements taken with pre-GEWEX technology. The MAGS project, located in Northwestern Canada utilized indigenous peoples traditional experiences. In addition, in other parts of

7800-590: The indirect effects of aerosols , compiled a correlated data set, some reductions in uncertainty GEWEX claims the following accomplishments: A long period data set of clouds , rain fall , water vapor , surface radiation, and aerosols with no indication of large global trends, but with evidence of regional variability, models showing increased precipitation, and showed the importance of regional factors, such as water and soil conservation in regional climate change. The Phase I also claims to have produced over 200 publications and 15 review articles. The Mississippi watershed

7904-406: The last 25 years and determined that global rainfall is 2.61 mm/day with a small statistical variation. While the study period is short, after 25 years of measurement regional trends are beginning to appear. The GEWEX Modeling and Prediction Panel takes current models and analyzes the models when climate forcing phenomena occur (global warming as an example of a 'climate forcing' event). GEWEX

8008-521: The late summer albedo in the northern hemisphere. In 2008, sea ice extent decline has backed off from the previous years' trend, and researchers had forecast a strong La Nina event for late 2007 and 2008. However, unexpectedly the surface temperatures in the Eastern Pacific have already begun to rise to El-Nino temperature ranges, indicating the La Nina event may terminate unexpectedly. With this,

8112-399: The long-term and regional changes in climate with a goal of predicting important seasonal weather patterns and climate changes that occurs over a few years. At 100% humidity, any loss of radiant energy from water causes vapor to condense into water. Circulation and convection can carry moist air upward in the air column, and this often cools moist air. The air forms water droplets, even in

8216-628: The loss of Northern Polar sea ice has begun to accelerate back toward the earlier trend. Such rapid and unexpected changes in climate-forcing events eventually suggest that modellers need to include parameters such as ocean temperature thermoclines, energy accumulation in the tropical oceans, sea ice extents in the polar regions, land glacial ice retraction in Greenland, and sheet ice and shelf ice remodelling in Antarctica. When multiple climate-forcing influences are acting simultaneously in which one of

8320-406: The modelling support is very generic. Samples are terminologies, taxonomies or ontologies. In a concept model each concept has a unique and distinguishable graphical representation, whereas semantic concepts are by default the same. In a concept model each concept has predefined properties that can be populated, whereas semantic concepts are related to concepts that are interpreted as properties. In

8424-569: The oceans and unpopulated regions, with key data missing from these areas. Since satellites orbiting the Earth cover large areas in small time frames, they can better estimate climate where measurements are infrequently taken. GEWEX was initiated by World Climate Research Programme (WCRP) to take advantage of environmental satellites such as TRMM , but now uses information from newer satellites as well as collections land-based instruments, such as BSRN . These land-based instruments can be used to verify information interpreted from satellite. GEWEX studies

8528-505: The overall system development life cycle. Figure 1 below, depicts the role of the conceptual model in a typical system development scheme. It is clear that if the conceptual model is not fully developed, the execution of fundamental system properties may not be implemented properly, giving way to future problems or system shortfalls. These failures do occur in the industry and have been linked to; lack of user input, incomplete or unclear requirements, and changing requirements. Those weak links in

8632-423: The pool of energy shifts to an unmonitored region so that the magnitude of the shift avoids computation. An example of climate-forcing anomalies might be used to describe the events of 1998 to 2002, a strong El-Nino/La Nina cycle. The onset of the cycle can be influenced by global warming, which facilitated a larger increase of warm water in the tropics, rapidly enough that the thermocline was tolerant. A thermocline

8736-432: The process itself which is really what happens. A process model is roughly an anticipation of what the process will look like. What the process shall be will be determined during actual system development. Conceptual models of human activity systems are used in soft systems methodology (SSM), which is a method of systems analysis concerned with the structuring of problems in management. These models are models of concepts;

8840-410: The project, as with losses of ice and changes of climate on the ice edges. Model (abstract) The term conceptual model refers to any model that is formed after a conceptualization or generalization process. Conceptual models are often abstractions of things in the real world, whether physical or social. Semantic studies are relevant to various stages of concept formation . Semantics

8944-468: The purposes of understanding and communication. A conceptual model's primary objective is to convey the fundamental principles and basic functionality of the system which it represents. Also, a conceptual model must be developed in such a way as to provide an easily understood system interpretation for the model's users. A conceptual model, when implemented properly, should satisfy four fundamental objectives. The conceptual model plays an important role in

9048-542: The rain fell it cooled the air and dissipated heat, and as new moisture arrived, the process continued. When the sun did come out, it heated wet ground, which created more rain. Aerosols over the ocean can cause a lack of sufficient heat in the middle of the day to create sufficiently humid air. When the air reaches land, which may be warmer, there may be inadequate convection and other processes to create rains, and this can cause droughts. To better see these events progress, scientists need data and models to see what elements of

9152-462: The recommendations of Gemino and Wand can be applied in order to properly evaluate the scope of the conceptual model in question. Understanding the conceptual models scope will lead to a more informed selection of a technique that properly addresses that particular model. In summary, when deciding between modeling techniques, answering the following questions would allow one to address some important conceptual modeling considerations. Another function of

9256-460: The same way logicians axiomatize the principles of logic . The aim of these attempts is to construct a formal system that will not produce theoretical consequences that are contrary to what is found in reality . Predictions or other statements drawn from such a formal system mirror or map the real world only insofar as these scientific models are true. A statistical model is a probability distribution function proposed as generating data. In

9360-451: The satellites data is not useful for global weather prediction. The proposed Soil Moisture and Ocean Salinity satellite would provide the detail of soil moisture information on a daily basis may provide the data needed for real time forecasting. Phase II, "Full Implementation" (2003–2012) of GEWEX is to "exploit new capabilities" developed during phase I such as new satellite information and, increasingly, new models. These include changes in

9464-461: The simulation conceptual model is to provide a rational and factual basis for assessment of simulation application appropriateness. In cognitive psychology and philosophy of mind, a mental model is a representation of something in the mind, but a mental model may also refer to a nonphysical external model of the mind itself. A metaphysical model is a type of conceptual model which is distinguished from other conceptual models by its proposed scope;

9568-485: The structural model elements comprising that problem domain. A domain model may also include a number of conceptual views, where each view is pertinent to a particular subject area of the domain or to a particular subset of the domain model which is of interest to a stakeholder of the domain model. Like entity–relationship models, domain models can be used to model concepts or to model real world objects and events. flux Too Many Requests If you report this error to

9672-527: The structure, behavior, and more views of a system . A system model can represent multiple views of a system by using two different approaches. The first one is the non-architectural approach and the second one is the architectural approach. The non-architectural approach respectively picks a model for each view. The architectural approach, also known as system architecture , instead of picking many heterogeneous and unrelated models, will use only one integrated architectural model. In business process modelling

9776-519: The study observes cloud systems at single fixed positions on earth in order to better estimate their parameters. These four areas are: Azores and Madeira Islands, Barbados, Equatorial Western Pacific, and Atlantic Tropics. The initial data collection is complete, methods developed for land and aircraft-based observations can be compared with satellite observations so that better models of cloud system identification can be made at smaller scales. Global Land/Atmosphere System Study ( GLASS ) tries to understand

9880-410: The subject of modeling, especially useful for translating between disparate models (as functors between categories). A scientific model is a simplified abstract view of a complex reality. A scientific model represents empirical objects, phenomena, and physical processes in a logical way. Attempts to formalize the principles of the empirical sciences use an interpretation to model reality, in

9984-417: The system design and development process can be traced to improper execution of the fundamental objectives of conceptual modeling. The importance of conceptual modeling is evident when such systemic failures are mitigated by thorough system development and adherence to proven development objectives/techniques. Numerous techniques can be applied across multiple disciplines to increase the user's understanding of

10088-472: The system or misunderstanding of key system concepts could lead to problems in that system's realization. The conceptual model language task will further allow an appropriate technique to be chosen. The difference between creating a system conceptual model to convey system functionality and creating a system conceptual model to interpret that functionality could involve two completely different types of conceptual modeling languages. Gemino and Wand go on to expand

10192-537: The system to be modeled. A few techniques are briefly described in the following text, however, many more exist or are being developed. Some commonly used conceptual modeling techniques and methods include: workflow modeling, workforce modeling , rapid application development , object-role modeling , and the Unified Modeling Language (UML). Data flow modeling (DFM) is a basic conceptual modeling technique that graphically represents elements of

10296-469: The water budget which can be used by people for agricultural and other processes. GEWEX is a collaboration of researchers worldwide to find better ways of studying the water cycle and how it transforms energy through the atmosphere . If the Earth's climates were identical from year to year, then people could predict when, where and what crops to plant. However, the instability created by solar variation, weather trends, and chaotic events creates weather that

10400-409: The water, creating a cyclone. A cyclone is a stereotype energy transfer system. It gathers steam off of warm water and quickly moves it upwards releasing the energy into space. This causes the characteristic rain bands. The energy transferred is so great it gives rise to catastrophic winds, which disturb surface waters, increasing steam release, and also increase the rate at which moisture is drawn into

10504-479: The water-system consequences of predictions and global climate change. GEWEX Radiation panel ( GRP ) is a collaborative organization with a goal of reviewing theoretical and experimental knowledge of radiative processes within the climate system. Sixty percent of the energy that comes to Earth from the Sun is transformed by the earth. The goals of this collaboration is to determine how energy is transformed as it inevitably

10608-436: Was also to advance the development of observing techniques, data management, and assimilation systems for operational application to long-range weather forecasts, hydrology, and climate predictions. During Phase I GEWEX projects were divided into the three overlapping sectors. CEOP projects interacted with other non-GEWEX projects like CLIVAR and CLiC The results of the build-up phase include 15 to 25 years of study, measured

10712-602: Was inadequate information on how radiation redistributed, both horizontally and vertically. BSRN is a global system of less than 40 widely spread radiation measuring devices designed to measure changes in radiation at the Earth's surface. The information obtained is stored at the World Radiation Monitoring Center (WRMC) at the ETH (Zurich). Established by Radiation Sciences Program(NASA) and GEWEX in 1998 to analyze satellite and field data to determine

10816-627: Was part of the GEWEX Continental scale International Projects and as a result was well situated for the analysis of the Great Flood of 1993 ( Mississippi River and Red River watersheds). The coordination between ground sensing observations and satellite information allowed a more thorough analysis of events that led up to the flood. Researchers at the Center for Ocean-Land-Atmosphere Studies (COLA) found that upstream soil moisture and

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