Week 5: 21 Sept
Monday
Preparing for HW3 talks on Thursday (or earlier if ready).
How much water would it take to have a pressure equal to that of the entire atmosphere? (10 meters or about 33 feet).
Watch this video on Atmospheric Rivers.
Atmospheric river discussion.
Week 4: 14 Sept
Thursday
3. How much water would it take to have a pressure equal to that of the entire atmosphere?
More on atmospheric rivers. Would we ever expect an atmospheric river in Rochambeau or Barrow?
Watch this video on Atmospheric Rivers.
Atmospheric river discussion.
Wednesday
1. Air in the north has an approximate scale height of 6.8 km. In the south, it is 8.6 km. Assuming they both have a surface pressure of 1000 hPa, calculate calculate the pressure at 1 km, 5 km, and 10 km. Based on this, what direction would wind go, toward the north, south, east or west at 10 km?
Answer:
| Height (km) | Pressure, south where H=8.6 km (mb) | Pressure, north where H=6.8 km (mb) | Pressure Difference (mb) |
| 1 | 890 | 863 | 27 |
| 5 | 559 | 479 | 80 |
| 10 | 313 | 230 |
83 |
Wind expected first from the south and then from the west in time as the Coriolis force affects the motion.
2. An air parcel at 750 mb has a dewpoint of 10 C and an air temperature of 15 C.
a.
Find its relative humidity, water vapor mixing ratio, and virtual temperature in Kelvin.
b. Calculate its density if it were dry (dew point 0 K) and at its RH.
c. Assuming that the moist air is an air parcel in in its dry environment, calculate its buoyancy, b=g(ρenv - ρparcel)/ρenv.
Answer: SkewT diagram. a. RH=wsat(Tdew) / wsat(T) = 10 g/kg / 13.5 g/kg = 74%. w=wsat(Tdew) = 10 g/kg T=288 K. Tv = T (1 + 0.61w) = 290 K b and c. ρ = P/RDTv RD=287.1 J/kgK ρdry=0.907 kg/m3 ρ=0.900 kg/m3 b=0.054 m/s2 |
Board 1, board 2, fire 1, fire 2, fire 3.
Monday - Tuesday
Hydrostatic equation, virtual temperature for use to obtain the correct density, exponentially decaying dependence of pressure with height, pressure in water. Pg1, Pg2, and Pg3.
Problem 1.21 analysis and discuss the averaged hemispherical pressure from the homework page.
Whiteboard notes pg1, pg2, and pg3.
Discuss Homework 3. Everyone choose a sounding from a different month.
Install the Anaconda/Python interpreter for the HW3 script.
To create a recent model sounding using HRRR, start at the Continental US scale and click on any point. This will bring up a sounding. Choose on where radar indicates active precipitation, and compare with another elsewhere. Notice the Dendrite Grow Zone (DGR) elevations and associated temperatures.
Week 3: 8 Sept
Thursday
Talk about HW2 South Pole lapse rate and sea level equivalent pressure changes in summer and winter.
Fire field project description (Eliza).
Problem 1.21 analysis and discuss the averaged hemispherical pressure from the homework page.
Grand Junction Colorado example of a lifted air parcel from the averaged 50 mb from the surface mixing ratio and potential temperature (image). Excel analysis to get lifted air parcel starting point for LCL and CAPE.
Surface layer, near-surface friction to air motion over water and land, dependence on turbulent boundary layer, and finally, above, geostrophic flow is possible.
Tuesday and Wednesday
Presentations continue for HW1.
Week 2: 31 August
Thursday
Start presentations for HW1.
Tuesday and Wednesday
Discuss the free atmosphere and planetary boundary layer from the Monday soundings. Work towards HW 2.
Monday
Discuss dry adiabats: from PVγ = constant for a gas at pressure P and Volume undergoing an adiabatic process to potential temperature. Dry adiabats on the SkewT diagram.
Reno sounding from yesterday afternoon and this morning.
Bring questions to class on HW 1.
How to read skewT ln P diagrams. (local backup).
Overview Presentation: Work towards HW 2.
Stationary lee wave clouds downwind of the Sierra Nevada mountains.
Week 1: 24 August
Tuesday - Thursday
Work on HW 1.
Overview Presentation: Note the large hail in South Dakota, and thus the need to work on hail suppression.
Stationary lee wave clouds downwind of the Sierra Nevada mountains.
How to read skewT ln P diagrams. (local backup).
Do a Convective Condensation Level example for how much heating the atmosphere must have to get a pyrocumulus cloud associated with wild fires (CCL).
MODIS imagery from August 19th 2020 (fire detection and vast amounts of smoke).
NOTE: SkewT ln P images can be obtained from:
|
Monday
Outcome: Student introductions, syllabus, homework discussion, and started discussion of Atmospheric Physics, especially fires, smoke and clouds.
Thanks for the questions 😀 I appreciate them immensely!
| Introductions -- each student introduce themselves. |
| Syllabus. |
| Homework. |
| Webcampus for online homework assignments/reading. |
|
Online Homework 1 is due August 30th. See webcampus. Online Homework 2 is due September 6th. See webcampus. Homework 1 is due September 4th, to be turned in through web campus. For this week: Read chapter 1, introduction to large scale features of the atmosphere. |
The final project has been posted. |
This class includes:
Lecture/discussion in class.
Active class participation/activity involving atmospheric data from around the world.
Study using online modules for atmospheric science education.
Chapter 1: Introduction and overview:
The layers of the Earth's atmosphere.
Vertical structure of the atmosphere.
Overview Presentation: Atmospheric Science relies heavily on measurements and models!
Composition of the Earth's atmosphere.
Related Information:
