Difference between freshwater lakes and oceans in terms of the formation of ice
Ocean ice is found in Polar Regions. It covers an area of 25 million square kilometers. Ocean ice forms on the surface of the ocean. It grows and melts above oceans. During winter, ocean ice grows but melts during summer (Thompson & William 1). The occurrence of ocean ice has a direct influence on the global climate. Ocean ice has a bright surface that reflects most of the light that strikes it. The co sequence of this phenomenon is that areas that the ocean ice covers have low absorption of solar energy (Ilker 149). In this regard, the temperatures in the solar regions remain cool compared to temperatures of regions covered by lakes. Warm temperatures across the world melt ocean ice. When this happens, the size of bight surfaces available reduces. This increases the amount of solar radiation absorption. The increase in solar radiations leads an increase in temperature at the surface. Thus, a cycle of warming and melting is constituted. The cycle is hindered during winter but commences during spring.
On the other hand, lake ice occurs on fresh water. It freezes as a smooth layer that forms and shapes due to the frequent turbulence of ocean water (Riley et al., 2). Fresh water becomes less dense as it approaches freezing point. This phenomenon is the reason why ice cubes float on the surface of water and why ice layer forms on the surface of lakes and rivers (Nguyen et al., 73). The ocean water increases the density of water when it approaches the freezing point. Because of this, Cold Ocean waters sinks, making ocean ice to form at a slower pace than lake ice. As the water sinks, it cools enough to freeze. In this regard, ice formation on ocean becomes slow process compared to ice formation above the lake. Salt water has a low freezing point compared to fresh water. This is because of the deep levels of ocean water. For ice to form, this water must be cooled to the freezing temperature.
Bottom temperature in lakes
The temperature at the bottom of the lakes is usually cold. This is because of the deep levels of lake waters. Water attains a maximum temperature of 4 Degrees Celsius. The water and ice that exist at temperatures below 4 degree Celsius is less dense. The density of water increases from top to bottom (Lagerloef et al., 72). This means that the temperature of water that will be found at the bottom of the lake is 4 degree Celsius. Water inside a lake is arranged according to the temperature. High temperatures imply that the water is less dense (Baucher et al., 486). Layers of lake waters with low density are formed at the top of the lake water. Thus, high densities of water are found at the bottom of the lake. If a region of water is 4 degrees Celsius while another region of water is 6 degrees Celsius, it implies that there is a region of water with 5 degrees Celsius. This systematic arrangement on the basis of temperature differences defines the nature of water. The top of water begins to freeze when the lake turns 4 degrees Celsius. This means that this temperature is critical for the formation of ice at the surface of the lake.
Fall and spring
Various thermal processes take place on the lakes during fall and spring. The absorption of light energy by the water leads to conversion of the heat energy. This heat initiates the warming process of the lake. Lakes that are stratified according to the differences in thermal processes experience warm surfaces and cooler bottoms during spring. The warm surface of lake waters is called the epilimnion while the cooler bottom is called hypolimnion (Riley et al., 3). A thermal barrier is created between these two zones. Mixing water of varying densities require energy. This energy is relative to the differences in the density. In some cases, wind offers the energy needed to mix water of different densities. This occurs when wind initiates the movement of water molecules that eventually forms water currents (Thompson & William, 2). The depth of epilimnion is defined the capacity of wind to mix water at the surface. The degree of exposure of the lake water to wind determines the depth of thermocline. During fall, the thermocline creates a strong and effective barrier relative to mixing of the water column. This event separates the hypolimnion from gas exchanges. This zone is exposed to limited light. Thus, green plants are not able to carry out the process of photosynthesis effectively due limited oxygen. The temperature zonation breaks down during spring leading to the cooling of epilimnion. The reduction of the thermal barrier leads to mixing of the water from the top to the bottom (Tomczak 7). This behavior takes place in the oceans as well. However, the mixing of ocean waters is limited to a certain depth.
Oceans have sea ice in regions that have stringer haloclines of the vertical stratification between the warm surface waters and deep waters (Laevastu 2). Thus, halocline occurs because of the strong salinity gradient within the ocean.
Works Cited
Bauch, Dorothea, et al. "Origin of freshwater and polynya water in the Arctic Ocean halocline in summer 2007." Progress in Oceanography 91.4 (2011): 482-495.
Ilker, F. E. R. "Weak vertical diffusion allows maintenance of cold halocline in the central Arctic." Atmospheric and Oceanic Science Letters 2.3 (2009): 148-152.
Laevastu, Tavio. "Fisheries oceanography." Pearson. (2013).
Lagerloef, G., et al. "A. deCharon, G. Feldman, and C. Swift. 2008. The Aquarius/SAC-D mission: Designed to meet the salinity remote-sensing challenge." Oceanography 21.1 (2008): 68-81.
Nguyen, A. T., D. Menemenlis, and R. Kwok. "Improved modeling of the Arctic halocline with a subgrid‐scale brine rejection parameterization." Journal of Geophysical Research: Oceans (1978–2012) 114.C11 (2009).
Riley, John Price, and Roy Chester, eds. Chemical oceanography. Elsevier, 2013.
Thomson, Richard E., and William J. Emery. Data analysis methods in physical oceanography. Newnes, 2014.
Tomczak, Matthias, and J. Stuart Godfrey. Regional oceanography: an introduction. Elsevier, 2013.
