Northern Lights essays

Northern Lights essays The book I decided to read for the assignment is The Northern Lights written by Lucy Jago. This book by Jago details the true story of Kristian Birkeland, the man who put his life aside to figure out the secrets of the Northern Lights. This book describes the Journey of six men who climbed to the tallest peaks of Haldde Mountain to record and study the aurora borealis. These Six men were; Clement Isaakson Haetta, Kristian Olaf Birkeland, Bjorn Helland-Hansen, Elisar Boye, Kristoffer Knudsen, and Sem Saeland. While spending six months during the fierce winter, the six men recorded data off of state of the art instruments like the anemometer, which was used to record wind speeds. Also used was a Barometer to tell whether the air pressure changed during the aurora shows, while the Hygrometer measured the air humidity. The most important instrument used though was the magnetometers, which was used to measure changes in the strength and direction and the Earths magnetic field. Birkeland hoped that these instruments would give them answers to many questions asked about the bright lights. Some questions they were hoping to answer were; are the lights accompanied by a crackling noise, could the lights make hair sta nd on end, did they touch the ground, did they occur during daytime? By the end of the winter Birkeland was convinced that his theory, that the force disturbing the magnetic field came directly from the sun in narrow beams of electrically charged particles called cathode rays, was correct. A British scientist once showed that cathode rays consisted of high velocity streams of negatively charged particles: electrons. Birkeland was convinced that the Sun put out similar rays and that these particles hit the magnetic field of the earth and followed the field lines down toward the poles, where they struck atoms in the atmosphere and the energy created by the collisions was ...

Forest Ecosystem and Biodiversity Definitions

Forest Ecosystem and Biodiversity Definitions A forest ecosystem is the basic ecologic unit in a particular forest that exists as home for a community of both native and introduced classified organisms.  A  forest ecosystem is  named for the primary tree species that form the canopy. It is defined  by all the collective living inhabitants of that forest ecosystem that co-exist together in symbiosis to create a unique ecology.   In other words, a forest ecosystem is typically associated with land masses covered in trees and those trees are often  classified by foresters into  forest cover types. Examples of just a few  broad names in North America are The northern hardwood ecosystem, the ponderosa pine ecosystem, the bottomland hardwood  forest ecosystem, the jack pine forest ecosystem and so on. The forest ecosystem is just one of a number of unique ecosystems including prairies, deserts, polar regions, and great oceans, smaller lakes, and rivers. Forest Ecology and Biodiversity The word ecology comes from the Greek oikos, meaning household or place to live. These ecosystems or communities are usually self-sustaining. The word usually is used because some of these communities can become unbalanced very quickly when detrimental factors occur. Some ecosystems, like tundra, coral reefs, wetlands, and grasslands are very fragile and very small changes can affect their health. Larger ecosystems with wide diversity are much more stable and somewhat resistant to harmful changes. A forest ecosystem community is directly related to species diversity. Generally, you can assume that the more complex the structure, the greater is its species diversity. You should remember that a forest community is much more than just the sum of its trees. A forest is a system that supports interacting units including trees, soil, insects, animals, and man. How a Forest Ecosystem Matures Forest ecosystems tend to always be moving toward maturity or into what foresters call a climax forest. This maturing, also called forest succession, of the ecosystem increases diversity up to the point of old age where the system slowly collapses. One forestry example of this is the growth of trees and the entire system moving  toward an old growth forest. When an ecosystem is exploited and exploitation is maintained or when components of the forest begin to naturally die, then that maturing forest ecosystem goes into declining tree health. Management of forests for sustainability is desirable when forest diversity is threatened by overuse, resource exploitation, old age, and poor management. Forest ecosystems can be disrupted and harmed when not properly sustained. A sustained forest that is certified by a qualified certification program gives some assurance that the forest is managed to allow maximum diversity while satisfying the managers environmental and economic demands. Scientists and foresters have dedicated their entire careers trying to understand even a small part of forest ecosystems. Complex forest ecosystems are extremely diverse, ranging from dry desert shrub land to large temperate rain forests. These natural resource professionals have categorized forest ecosystems in North America by placing them into forest biomes. Forest biomes are broad categories of natural tree/plant communities.