Increases Accuracy Of Global Studies Emil Venere Homewood News and Information Xun Zhu, a research scientist in the Department of Earth and Planetary Sciences, has created a new mathematical technique that will significantly increase the accuracy of computer models used for studying global changes of Earth's environment, such as ozone depletion and global warming caused by pollution. Such models work by using equations to study and predict atmospheric dynamics and the transfer of energy in the atmosphere. Usually, the solar energy absorbed by the Earth's atmosphere is calculated by comparing the number of photons entering one section of atmosphere with the number of photons exiting a second section. The difference is the number of photons absorbed. He presented a paper about the work on May 20, during the American Geophysical Union's Spring Meeting in Baltimore.
Environmental predictions are only as good as the models they are based on, so accuracy is critical.
But the models currently in use are subject to a high degree of error. If, for example, the calculation starts with 1,002 photons passing through the first section of atmosphere, and 1,000 photons passing through the second section, the difference is two photons, meaning two photons have been absorbed. Zhu has developed a mathematical solution to this problem. After five years of work, he has invented a computational method that directly calculates the number of photons absorbed in a given volume of atmosphere. That means there is no need to compare the number of photons passing through the two sections of atmosphere, eliminating a major source of error, he said.