GEOGRAPHY Assignment L08

GEOGRAPHY 111 (L08) Submitted to- Terence Day Submitted by- Karanveer Singh ASSIGNMENT: Atmospheric Moisture and Stability

1. Table 8.5. Conversions between moisture variables. °Calculations: Dry-bulb temperature (T) Wet-bulb temperature (T W ) Wet-bulb depression (T-T W ) Relative humidity (RH) Saturation vapour pressure (e s ) Actual vapour pressure (e) Dew point temperature (T d ) a) 13°C 11°C 2°C 80.4% 1496 1202.27Pa 9.7°C b) 15°C 9°C 6°C 53.4% 1705 910.47Pa 5.6°C c) 28°C 23.5°C 4.5°C 70.1% 3778 2648.37Pa 22°C d) 20°C N/A N/A 64.10% 2338 1498.6Pa 13.0°C e) 5°C 3.5°C 1.5°C 80.8% 873 705 Pa 2°C f) 28 N/A N/A 59.8% 3779 Pa 2267 Pa 19.4°C g) 24°C 24°C 0°C 100% 2984Pa 2984Pa 24.0°C Wet-bulb depression=T-Tw(°C) a) (T-Tw) =13°C-11°C=2°C b) (T-Tw) =15°C-6°C=9°C Actual vapour pressure (e) e(pa)=es(pa)×RH/100 a)1496×80.4/100=1202.78Pa b)1705×53.4/100=910.47Pa c)3778×70.1/100=2648.37Pa d)2338×64.10/100=1498.6Pa e)837×80.8/100=676.296Pa f)3779×59.5/100=2248.5Pa g)2984×100/100=2984Pa Relative Humidity RH (%) =e(Pa)/es (Pa)×100% EXERCISE 1: MOISTURE VARIABLES

e) x1=1, x2=2, y1=657, y2=706, y3=705, x3=? X3=x1+(y3-y1) (y2-y1) ×(x2-x1) x3=1+(705-657) / (706-657) ×(2-1) x3=1+(48/49) ×1 x3=1+0.97 x3=1.97 2. On a cold snowy day, the outside air temperature is 0°C and the relative humidity is 100%. The air is taken into the house and heated to 21°C. What is the relative humidity inside the house? Answer- Actual vapour pressure at 0°C=611Pa Saturation vapour pressure at 21°c =2487Pa RH (relative humidity at 21°C=actual vapour pressure/saturation vapour pressure*100 = 611/2487*100 =24.56% 3. Dew is often formed on grass early in the morning but not at other times of the day. Explain why this is. Answer- Dew forms on grass early in the morning because the temperature drops during the night, and it reaches the dew point temperature. The air is often humid in the morning due to condensation so, it can no longer hold all the moisture, so it condenses on grass. This process doesn’t occur during the other times of the day because the temperature rises, the air can hold moisture, so dew doesn’t form. 4. Go to Historical Data Report for Kelowna International Airport. Check that the date matches today’s date. Have a look at the relative humidity. Next, click the Previous Day button located to the left of the date bar, and track the relative humidity over the preceding 3-4 days. Think back to how you felt over those days. Do you feel more comfortable when the RH is high, or low? Explain the major factors that affect RH. Answer- In Kelowna humidity was almost 50% in last couple of days. Humidity in air is not good for me, because high humidity means when I do physical activities sweat from the body do not dry and I felt hot on those days. Factors affecting RH :1 ) Temperature - RH decreases when temperature increases because warm air can hold moisture. EXERCISE 2: ATMOSPHERIC MOISTURE

2) Air pressure- change in atmospheric pressure affects the relative humidity. Increase in air pressure prevent the cloud formation which leads decrease in RH, while low pressure may increase RH. 3)Altitude- Relative humidity changes with altitude. As air rises, it cools, and increases the RH and cause condensation which forms the clouds. 5. Search online to acquire the company names and model numbers of at least two different instruments (other than the sling psychrometer) for sensing humidity. Answer- 1 ) Dew point meter- This instrument measures the temperature at which air becomes saturated with moisture and dew forms. Company name-TEKHNE Model Number-TK-100 2) Hygrometer- measuring humidity. Company name- S.L Technologies Model number-288-ATH