Motivational letter for PHD

I want to apply a Phd position in Germany. Because English is not my native language, it's difficult for me to write a competely correct motivation letter. Please help me to revise my motivation letter:

Dear ***,

I have completed my five year Master of Physics program at the University of ***, Faculty of Sciences. I graduated in 2010 with a master degree in Physics, in scientific area Meteorology and with grade point average 9.0. I am currently working at University of *** as teaching assistant in several Physics courses. I am applying for the PHD position on Short-term variability of solar irradiance research project at the ***. Detailed information about my academic record and my research and other experience is attached to this statement.
Through academic study I have acquired excellent knowledge in atmospheric physics and numerical modeling. In particular, I am interested in the solar radiation modeling. This interest developed during my studies and research activities through courses ‘Transfer of Radiation through the Atmosphere’, ‘Modeling of Physical Processes in the Atmosphere’ and ‘Meteorological observations and data processing’ in which I gained knowledge and explored relationship between physical basis of solar radiation and solar radiation modeling and measurements. I developed my interest and continued further research in this area through my master thesis ‘Analysis of statistical and dynamical methods of global solar radiation modeling’. In my Master thesis I analyzed statistical methods based on pyranometer and satellite derived data of measured global radiation and dynamical methods of solar radiation modeling based on numerical model outputs.
As exceptionally good student immediately after completion of my studies I employed at the University of *** as teaching assistant at several Physics courses. Some of the courses that I hold, such as ‘Radiation in Atmosphere’ and ‘Civil Engineering Physics’ are directly related to photovoltaic power systems. Course work expanded my knowledge and experience in energy efficiency and solar radiation. Through my work with students I perfected my analytical thinking skills, high level of responsibility and communicational skills. I like expressing my ideas and concepts both in oral and written form, which is ideal platform for the dissemination of knowledge in my chosen field of specialization.
From beginning of my academic studies I have been highly interested in solar radiation modeling and my long-term goal is to receive PHD degree and continue my research in field of energy meteorology. Given my past experience, academic qualification and my strong interest I believe I have qualities to be good researcher at this project. I am certain that, if given the opportunity, I would excel under the guidance of the respectable researcher in the field of energy meteorology.

Yours sincerely,
***