Simulated seasonal variations in nitrogen wet deposition over East Asia was written by Jin-Hui Yu, Mel-Gen Zhang and Jia-Linv Li. http://www.tandfonline.com/doi/abs/10.1080/16742834.2015.1136782 

The purpose of this study was to simulate the rain fall patterns in China and to measure where the most nitrogen and sulfur pollutants were falling though out the country and see if there was a difference depending on what season it is. In this study the researchers focused more in the amount of nitrogen wet amounts, which refers to the amount of nitrogen in precipitation like rain or snow. In order to be able to observe this the researchers applied the regional air quality modeling system Regional Atmospheric Modeling System–Community Multiscale Air Quality to estimate the spatial distribution and seasonal variation in nitrogen wet deposition over East Asia, though the article tends to concentrate more on China. “The simulated results were evaluated by comparing modeled precipitation rates and ion concentrations, such as ammonium , nitrate, and sulfate, in rainwater, against observations obtained from Acid Deposition Monitoring Network in East Asia and [weather stations] in China” (Jin-Hui Yu, Zhang, Li).

Once they had collected the data the researchers compared their modeled data to what they observed using the weather station and found that modeling system reproduces fairly accurate seasonal precipitation patterns.  Analysis of the modeled wet deposition distributions indicated that China experiences noticeable variation in wet deposition patterns throughout the year.

This study was conduced because even though many nitrogen deposition measurement programs have been launched in China since the 1980s the fluxes in nitrogen wet deposition were calculated only by using a few sites. A systematic nationwide monitoring network to obtain nitrogen deposition distribution data is absent in China, leading to insufficient information on regional-scale nitrogen deposition. These measurements were much fewer than those of the United States and most European countries so these researchers sought to try and fix this issue but doing a more accurate and modern measurement.

The type of data used to learn how much variation there was between a model and observed rain fall was through a report of and act and an actually action taken, which was to go to a weather station and observe the amounts of nitrogen in that rain. This research would be useful to see how various air currents effect the amounts of acid rain around the country and to better understand how much of the unnaturally present nitrogen in the surrounding countries is actually from China and not a product of their own actions. This could also be useful to compare with older data around similar topics to see if there is a correlation between them.

Yu, Jin-Hai, Mei-Gen Zhang, and Jia-Lin Li. “Simulated Seasonal Variations in Nitrogen Wet Deposition over East Asia.” Atmospheric and Oceanic Science Letters 9.2 (2016): 99-106. Web.