ATOC 1070 Weather Lab Section 001 Lab1: Pamela Negel Lab section | Mondays 9:20-11:30 am Monday February 11th, 2019 Objective: In this lab, moisture in the atmosphere, we will be looking into the measurement role of water in the atmosphere. Meanwhile, we will be defining ways to measure humidity in our atmosphere. Including, relative, absolute, specific, and vapor pressure. We will also look further into dew point temperature. Ultimately we will understand how "raw" observations are reduced into more useful forms and explain the relationship between air temperature and relative humidity. We were able to do this by using a psychomotor to measure the moisture in the atmosphere. We will then took these temperature values and convert them into dew point and humidity levels by using a psychrometric table. I predict that the more water present in the air, the hotter/moisture the air temperature will feel, and the higher the dew point temperature will be. Procedures: We began by understanding how the psychrometer worked and how we should go about finding the temperature data.We first went ahead and wet the cotton side of the psychrometer, which is what found the temperature of the the wet bulb temperature. The otherside was dry, so we were able to compare the two temperature readings. We then were able to record the original temperature of the wet bulb. We started inside and whirled the thermometer in a circle for about 30 seconds, and then went outside recorded both the wet and dry temperatures displayed on the barometer. We continued to whirl the thermometer in 30-second increments until we receive two of the same wet bulb temperatures. Once we found the measurements we were able to find the dew point by looking at the chart and put all of the information into the spreadsheet.Spreadsheet:Question 1: a. The vapor pressure is 5mb and the saturation vapor pressure is 25mb at 21ºC. (5mb)/(25mb)*100= 20% relative humidity b. The vapor pressure is 15mb and the saturation vapor pressure is 25mb at 21ºC. (15mb)/ 25mb)*100=60% relative humidity c. The mixing ratio is 10g/kg, and the saturation mixing ratio is 20g/kg at 25ºC (10g/kg)/20g/kg)*100= 50% relative humidity d. The mixing ratio is 10g/kg, and the saturation mixing ratio at 10g/kg at 15ºC (10g/kg)/(10g/kg)*100 = 100% relative humidity e. With the help of the equations above, relative humidity can be changed because it depends on air saturation and water vapor. In questions A & B it displays how temperature does not affect the relative humidity in the atmosphere. If the vapor pressure increased, the relative humidity becomes higher. When water vapor pressure increased, as did the relative humidity. This is indicating that vapor pressure and relative humidity have a direct relationship. In question C as well as D, it shows us that saturation mixing ratio to a lowered number, the R.H increases. As the capacity of the water in the air will lower with temperature, which causes less molecules in the air and a higher level of relative humidity.Question 2 a. The molar weight of the water vapor is 18g per mole, which is less than the molar weight of the dry air which is 29g per more. And because dry air is denser than the liquid, the dry air is more dense compared to the moist air mass. b. If the two air masses collide, the moist air mass would rise due to its lower density. This will cause it to become lighter which will make it easier for it to rise and the dry air would be pushed downwards. Question 3 a. In this lab, the air that contained the most moisture was inside. Before we got our results, I thought that there would be more moisture in the air outside since it was very cold and a bit snowy. But given what I learned, I realized that since it was colder outside, the warmer temperatures in the building allowed the air to hold more moisture then compared to the outside. b. We found the highest RH to be outside, according to the ATOC Skywatch website. While our outside calculations for relative humidity found that it was 66.2% while the Skywatch website read that it was 89.1% humidity. This Question 4 a. If I were to have taken another psychrometer reading a few minutes later, and the wet-bulb reading was 1 degree lower than before, the relative humidity and dew point temperature would have decreased and everything else would have stayed the same. I know this because the drop in the temperature would cause the vapor pressure to decrease. Since the two are in a direct relationship. b. The temperature requires more measurements since we had to take more than one measurement with two different thermometers. But once we found all our data, all we had to do is enter then into the table to find the dew point temperature. c. Essentially, I would expect that there would have been a higher deviation in regards to the dew point temperatures. Although it was clear that there were technical errors with the equipment we were using, the temperatures among the groups should have been relatively the same. But I believe what could have happened is the dew point temperature could have fluctuated a bit because of the water in the atmosphere could change quickly d. The data that had a stronger deviation in dew point which is what I had expected. The standard deviation of the dew point was 7.1, and 4.6 for the temperature. This met my expectation in part C. Explain how you accomplished the objectives that your experiment aimed to address. If you did not accomplish the objectives, explain why the experiment failed. While doing this lab we followed each step directly and appropriately, I think my partner and I successfully accomplished the objectives of this lab. We began by spinning around the psychrometer inside to find the wet-bulb and dry-bulb temperature measurements. After putting is data into ourspreadsheet, we went outside, waited around 30 seconds and recorded those temperatures as well. Once we recorded both, we went ahead and used the excel spreadsheet provided. This then allowed us to find the dew point temperature from outside and inside. When looking at our temperature data of the outdoor readings compared to others, our data was right around the middle of everyone else's. I believe that was a good way to understand that we successfully completed the experiment, given the circumstances of any faulty equipments. My partner and I correctly measured