Research Assignment about Ecosystems and Radiation (Research Paper Sample)

Ecosystems and Radiation
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Institution Affiliation
Introduction
Studying nature and the ecosystem is vital. We get to understand the environment better and the essential role that it plays in our lives. By studying ecosystems, we get to understand how we are either deliberately or non-deliberately negatively impacting the environment.
The outgoing and incoming energy to and from the atmosphere should balance in order for there to be sort of harmony between the earth and the atmosphere. Thermal energy radiated by the atmosphere is estimated to be about half of the incoming energy form the sun. about a quarter of the incoming solar radiation is absorbed by the ozone, aerosols, water and clouds while another quarter is transmitted to the atmosphere by evaporation and about 5 percent by convention (Trenberth et al, 2009).
When the efficiencies of conversion and budgets of ecosystems are compared, what affects energy flow and the tools that make a contribution to the world energy budget can be found. Solar energy only is not sufficient to sustain ecosystems, they also depend on energy for such sources as fossil fuels, animal and also human labor (Trenberth et al, 2009). In order to ensure a balance between energy lost and that which is gained, when a tree is cut down, to replace the energy gotten from the timber, cumulative inputs of energy from the sun are used to replace the biomass that has been lost.
Greenhouse gases such as methane and carbon (iv) oxide are a big threat to energy budget of ecosystem. There exists a balance between the energy to the earth from the sun through light and that from the earth to the sun through heat, and the atmosphere acts as a shield against these energies. The atmosphere is transparent and allows light energy from the sun to pass through while absorbing the heat radiated from the earth. Greenhouse gases act as a reflection against heat radiation that is escaping from the earth to the atmosphere. The heat radiation, instead of escaping through the atmosphere to space, is held close to the surface of the earth. This causes overheating and warming on the earth’s surface. Compared to the atmosphere, greenhouse gases are not transparent to light and heat radiation, thus they cannot allow these energies to pass through (Pielke et al, 2002).
An increase in heat levels and global warming has affected ecosystems negatively. Temperatures have increased compared to where they were in the 17th century. The weather has become warmer and temperature in oceans have gone up considerably. With the increase in temperatures, heat waves have also become frequent affecting mostly countries with poor economies (Lohmann et al, 2005). Due to the rise in temperatures, glaciers are melting causing a rise in the sea and ocean level. Scientists believe that the level of sea and ocean has gone up by about 0.2 meters, pausing a big threat to ecosystem and humans that are located in coastal areas that are low lying. Ice and permafrost have melted due to global warming. For example, compared to about a decade ago, the Pedersen glacier has greatly reduced in volume as a large part of it has melted. When permafrost melts, the outcome is massive landslides and more greenhouse gases are released to the atmosphere (Chasmer et al, 2011).
Shortwave radiation is the energy radiated to the earth from the sun. it contains a greater amounts of energy compared to longwave radiation (Suttles et al, 1998). Because the sun contains a huge amount of energy and is very hot, it gives off this large amount of energy in the form of shortwave radiation. This radiation is essential for ecosystems because it enables processes such as heating of soil, photosynthesis, evaporation and transpiration. These four processes are very essential for ecosystems because they ensure the growth, development and survival of ecosystems (Suttles et al, 1998).
This study is carried out to determine how shortwave radiation affects canopy types and if each canopy type is impacted differently by this radiation. The study will also determine whether temperature levels have any difference in canopy heights. The questions that are addressed include whether different canopy heights have different canopy temperatures and also how much is incoming and outgoing shortwave radiation across different vegetation canopy types.
The incoming and reflected shortwave radiation among different canopy types differ. This is due to the fact that some canopies are shorter and hence only absorb shortwave radiation that has either scattered or has been reflected by taller canopies. On the other hand, different canopy heights will have different canopy temperatures because depending on the height, the canopies will absorb the sun’s shortwave radiation at different angles.
Methods
Data was collected, gathered and borrowed from secondary sources such as journals and scholarly articles. Study sites are the main sources of the data being used. Maize, soya bean and wheat canopies were the main measurements used. The measurements were gotten from Yucheng comprehensive experiment station while those for soya beans were obtained from Brooks Field (Flerchinger et al 2009). At Yucheng the wheat was grown for approximately 6 months. The spacing of rows for wheat was about 28cm while that for maize was about 70cm. The rows were such that they were facing the north-south direction. A pyranometer was used to collect the incoming radiation above the canopy per hour while a radiometer was used to observe the net radiation per hour above the canopy. The temperature collected using the radiometer for the maize canopy was measured in the days between the 229th and the 261st. Temperatures for the canopy leaves were collected at an interval of about 20cm when the leaves reached the height of between 60 and 200cm.
In Brooks Field, the soya beans were planted at a spacing of approximately 38cm with the rows facing a north-south direction. To measure the net radiation above the soya bean canopy a radiometer was used. A solarimeters with two tubes were used to collect shortwave radiation within the canopy which were put at 15cm from the ground. After every 7 days, the soya beans were measured for their total leaf area index. For leaves that were green, they had to be hand harvested for their leaf area index to be measured. A leaf area meter was used to measure their leaf area index. For the wheat and maize canopies their leaf area index was measured at a time interval of 5 days. To find the leaf area index, a combination of the average of approximately 50 plants that had been sampled, the number of leaves that each plant contained and the density of each plant was used.
Results
Fig 1.0 shows the influence of the technique used to calculate the total leaf area index and the number of layers of canopy on the radiation that is reaching below the surface of the canopy. (a) shows that for about an area index of 2.5 cm, there was the highest level of inconsistency, of about 8%. When putting into consideration a couple of classes of leaf angle it is important to use a leaf area of about 0.5 in each canopy layer.
Fig 1.1 shows the outgoing and incoming shortwave radiation for wheat canopy. For this period the leaf area index and the canopy height was approximately 3.8 square meters and 0.93m respectively.
Fig 1.2 represents the results that had both been measured and simulated from day 140 to 147. This was a period when green leaves were most prevalent. The leaf area index for the green leaves decreased from about 2.3 to about 0.8. Concurrently, the leaf area index for yellow leafs went up from 0.6 to about 2.1
On the 127th and 154th day, there was the highest absolute difference in downward shortwave radiation, about 35cm within the canopy. On the 127th day, there was a clear difference in the incoming shortwave radiation which was as a result of a slight decrease in the incoming shortwave radiation. The inconsistency on the 154th day was caused by the decrease in the leaf area which occurred in accordance with the optimum difference depicted in fig. 1.0.
Fig. 1.3 represents the radiation from within the canopy and that which has been reflected for the maize canopy. During this period the leaf area index was about 4.1 and 4.5 square meters. At midday there is the probability that direct shortwave radiation was going into the rows and onto the solarimeters which was used to measure this radiation. The distribution of leaf angle had a very small effect on the outgoing radiation.
To determine the temperature of the leaves of the canopy an infrared thermometer gun is used. This tool has its flows in that it has high throughput and its scope is constrained to some applications. The best approach in determining the temperatures of canopies at different weather times was by using the canopy temperature itself.
In fig. 2.0, between the 1st, 3rd and 5th night the temperatures were around 15.4 degrees Celsius. During the 2nd night the temperatures were low at around 11.7 Celsius degrees. The 4th night was the one with the highest temperatures, at 1.8 Celsius degrees. the mean leaf area index for the leaves was 3.54 square meters. Leaves from the upper canopy were significantly twice as large as the ones in the lower canopy. Nitrogen content in the lower canopy was considerably more than that of upper canopies.
Figures
A graph of downward diffusion at soil surface against leaf area index.
Fig. 1.0 number of canopy layers, represented by N on downward diffusion radiation that has been simulated at the surface of the soil when the extinction coefficient in (a) is being calculated and in (b) as a function of leaf area within the canopy (Flerchinger et al 2009).
A graph of Shortwave Radiation against day of the year
Fig. 1.1 shortwave radiation that has been both measured and simulated. (a) shows the downward shortwave rad...