GEG1301_Lab3_Atmosphere and ocean circulation

Student Name:___________________________ Student #:________________ Department of Geography, Environment and Geomatics GEG 1301 THE PHYSICAL ENVIRONMENT Fall 2022 Laboratory #3: The Atmosphere and Ocean Circulation Professor: Roxanne Frappier Due Date Group A01: November 15 th Group A02: November 22 nd Purpose: The purpose of this lab is to provide an introduction to atmospheric composition and stratification, and ocean currents and circulation . Students will learn about important atmospheric concepts, such as the role of temperature in controlling the amount of water vapour contained in an air parcel, and how atmospheric temperature and pressure change as a function of altitude. Students will also test their ability to locate and map global surface and deep- water currents, and examine the effects of salinity, density and temperature on water circulation. By completing this lab, students will become familiarized with producing tables and figures, as well as the creation and placement of appropriate captions. Critical thinking, simple mathematic skills, observations and descriptions, and knowledge of table and figure components are basic skills that will be acquired in this lab, and will be applicable in future geographic studies. Assignment:  Answer the following questions (#1-19) in the spaces provided.  The total points available for this assignment = 82 points  All lab assignments must be completed and handed in individually. Format:  Students will hand in (a) questions with completed answers, (b) 7 completed tables, (c) Figure 1 with an appropriate figure caption, and (d) completed Figures 3 and 4.  Tables and figures should be produced to the standards of the Department of Geography, Environment and Geomatics, University of Ottawa. For guidelines on proper formatting and presentation of

tables and figures, please see the lab manual provided with this course. SECTION 1 – COMPOSITION OF THE ATMOSPHERE (23 points) 1. Complete missing information in table below . The total mass of the atmosphere is about 5.15 x 10 16 kg. Create an appropriate caption for the table, and select the proper placement (Above? Below? To the right?). Ensure that your caption begins with “Table 1:”. (2 points) Atmospheric gas % of atmosphere Total mass (kg) Nitrogen (N 2 ) 78.09 Oxygen (O 2 ) Argon (Ar) 0.93 Other 0.03 2. During the summer months, residents of the Ottawa region often complain about the humidity. On those humid days the air feels heavier. Is humid air actually heavier than dry air? The following few steps will help you answer this question. Table 1 (above) presents gaseous composition of an air parcel with no water vapour. Table 2 presents the gaseous composition of a hypothetical air parcel, which contains 4% of water vapour. “Other gases” have been omitted and because values have been rounded up, the relative change in percentage is only noticeable in the nitrogen and the oxygen. Since water vapour (H 2 O) makes up 4% of the air parcel, the relative abundance of other gases diminishes by 4% (Nitrogen 3% and Oxygen 1%). Why does argon (Ar) remain at 1% ? (3 points) Table 2. Composition of an air parcel that contains 4% water vapour. Atmospheric gas % of atmosphere Nitrogen (N 2 ) 75 Oxygen (O 2 ) 20 Argon (Ar) 1 Water vapour 4

3. Table 3 presents the atomic mass number of the elements that constitute the atmospheric gases, and also that of hydrogen (one of the “other” gases). Also found in Table 4 are the gas formula and gas mass. It takes two atoms of the element nitrogen to produce nitrogen in its gaseous form (N 2 ); therefore the mass of a molecule of nitrogen is 28 (two atoms of atomic mass number of 14). The same can be said for oxygen and hydrogen. Argon, a noble gas, can exist in a monoatomic form , therefore the argon gas mass is of 40. Water vapour, the gaseous form of water, is composed of H 2 O: two atoms of hydrogen and one atom of oxygen. Complete Table 3. (3 points) Table 3. Gas mass of atmospheric gasses. Element Atomic mass number Gas formula Gas mass Nitrogen (N) 14 N 2 28 Oxygen (O) 16 O 2 Argon (Ar) 40 Ar 40 Hydrogen 1 H 2 2 - H 2 O 4. Remember our question: Is humid air heavier than dry air? Table 4 will give you more information to help you answer the question. The data in Table 4 is based on a hypothetical air parcel, which is composed of 100 molecules of gas. In the first column data is provided for dry air, which contains 0% water vapour. In the second column data is provided for humid air, which contains 4% water vapour. Complete the following table and include a caption, beginning with “Table 4:” . (10 points) Dry air parcel of 100 molecules (H 2 O = 0%) Humid air parcel of 100 molecules (H 2 O = 4%) Number of N 2 molecules Number of O 2 molecules 20 Number of Ar molecules 1 Number of H 2 O molecules 0 Mass of all N 2 molecules Mass of all O 2 molecules 672 Mass of all Ar molecules