The past century alone has seen global temperature increase by 0. Is this just part of the natural cycle? How much of this warming is due to the burning of fossil fuels? Is human nature affecting Mother Nature? What should we do? Our response to the challenge of global warming begins by formulating the right set of questions.
The first step in addressing the issue of global warming is to recognize that the warming pattern, if it continues, will probably not be uniform. The term "global warming" only tells part of the story; our attention should be focused on "global climate change. Some spots will warm, while others will cool; these changes, and the accompanying shifts in rainfall patterns, could relocate agricultural regions across the planet. By studying the oceans from space, we can unlock a vast store of information about our changing environment.
Climate is affected by both the biological and physical processes of the oceans. In addition, physical and biological processes affect each other creating a complex system. Both the ocean and the atmosphere transport roughly equal amounts of heat from Earth's equatorial regions - which are intensely heated by the Sun - toward the icy poles, which receive relatively little solar radiation. The atmosphere transports heat through a complex, worldwide pattern of winds; blowing across the sea surface, these winds drive corresponding patterns of ocean currents.
But the ocean currents move more slowly than the winds, and have much higher heat storage capacity. The winds drive ocean circulation transporting warm water to the poles along the sea surface.
As the water flows poleward, it releases heat into the atmosphere. In the far North Atlantic, some water sinks to the ocean floor. This water is eventually brought to the surface in many regions by mixing in the ocean, completing the oceanic conveyor belt see below. Changes in the distribution of heat within the belt are measured on time scales from tens to hundreds of years. While variations close to the ocean surface may induce relatively short-term climate changes, long-term changes in the deep ocean may not be detected for many generations.
The ocean is the thermal memory of the climate system. NASA satellite observations of the oceans of the past three decades have improved our understanding of global climate change by making global measurements needed for modeling the ocean-atmosphere climate system. Global data sets available on time scales of days to years and, looking ahead, to decades have been and will be a vital resource for scientists and policy makers in a wide range of fields.
Ocean surface topography and currents, vector winds both speed and direction , sea-surface temperature, and salinity are the critical variables for understanding the ocean-climate connection.
Scatterometers are used to measure vector winds. The SeaWinds scatterometer has provided scientists with the most detailed, continuous global view of ocean-surface winds to date, including the detailed structure of hurricanes, wide-driven circulation, and changes in the polar sea-ice masses. Scatterometer signals can penetrate through clouds and haze to measure conditions at the ocean surface, making them the only proven satellite instruments capable of measuring vector winds at sea level day and night, in nearly all weather conditions.
The following explanation about water molecules will help you understand why coastal areas tend to have more moderate temperatures. A water molecule consists of one oxygen O atom bonded to two hydrogen H atoms. For the oxygen atom, 2 electrons are in the first energy level and the remaining 6 electrons are in the next or second energy level. Hydrogen has an atomic number of 1, which means that hydrogen has one proton in the nucleus and one electron in the lowest energy level outside the nucleus.
The second energy level can hold 8 electrons, so each hydrogen atom shares its 1 electron with the oxygen atom, completing the second energy level and making a water molecule. The bonding between the oxygen atom and each hydrogen atom is known as covalent bonding because they share electrons to make a very stable water molecule. This geometry of the water molecule causes it to have positively and negatively changed ends, known as polarity.
Together, these data sets become key input in coupled Numerical Weather and Climate Prediction models. The WMO community therefore has a major stake in supporting ocean observations, research and services.
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The ocean covers 71 percent of the planet and holds 97 percent of its water, making the ocean a key factor in the storage and transfer of heat energy across the globe. The movement of this heat through local and global ocean currents affects the regulation of local weather conditions and temperature extremes, stabilization of global climate patterns, cycling of gases, and delivery of nutrients and larva to marine ecosystems.
Ocean currents are located at the ocean surface and in deep water below meters feet. They can move water horizontally and vertically and occur on both local and global scales. The topography and shape of ocean basins and nearby landmasses also influence ocean currents. These forces and physical characteristics affect the size, shape, speed, and direction of ocean currents.
Surface ocean currents can occur on local and global scales and are typically wind-driven, resulting in both horizontal and vertical water movement. Horizontal surface currents that are local and typically short term include rip currents, longshore currents, and tidal currents. In upwelling currents, vertical water movement and mixing brings cold, nutrient-rich water toward the surface while pushing warmer, less dense water downward, where it condenses and sinks.
This creates a cycle of upwelling and downwelling. Prevailing winds, ocean surface currents, and the associated mixing influence the physical, chemical, and biological characteristics of the ocean, as well as global climate. Deep ocean currents are density-driven and differ from surface currents in scale, speed, and energy. Water density is affected by the temperature, salinity saltiness , and depth of the water. The colder and saltier the ocean water, the denser it is.
The greater the density differences between different layers in the water column, the greater the mixing and circulation. Density differences in ocean water contribute to a global-scale circulation system, also called the global conveyor belt.
The global conveyor belt includes both surface and deep ocean currents that circulate the globe in a 1,year cycle. Density differences in ocean water drive the global conveyor belt. This global circulation system is also called thermohaline circulation. Thermo means temperature and haline means salinity salt content.
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