ATMS 317 Intermediate Meteorology [main page] [homework]




Week 16: 8 December

HW 6 part 1 discussion as a study aid.

Monday, 8 December, exam covering everything since the last one.
You may bring 2 pages (8.5" x 11") of notes.
Bring your calculator also.

Week 15: 1 December

Read the last sections of chapter 6.
We will look at thermal wind (see this presentation), warm and cold air advection,
and ageostrophic flow and its consequences. We'll work on problems 6.9, 6.10, 6.11, and 6.13 in class some too.

Examples

The year the weather went wild (1977). Note the parallels with the 2013-2014 and 2014-2015 winters as well.

Here's the set up for the storm we're having this week.

http://tropic.ssec.wisc.edu/…/mim…/epac/anim/latest72hrs.gif

Week 14: 24 November

Read chapter 6, Simple Steady Motion (here are notes from the first two sections).
We will look at thermal wind (see this presentation), warm and cold air advection,
and ageostrophic flow and its consequences.

Wednesday we'll have a visitor from the Reno National Weather Service Office:

Title: Weather Forecasting at the Reno National Weather Service Office

By: Zach Tolby, Reno NWS office employee
(also a graduate of the UNR Atmospheric Science Program)

When: Wednesday November 26th at 3 p.m.

Where: Physics Conference Room, 2nd floor, Leifson Physics Building

Notes: Zach will discuss practical aspects of weather forecasting from on the job experiences at the Reno National Weather Service. He will also discuss trends and educational requirements for obtaining jobs at the NWS as well as a new internship program. All are welcome to attend.

 

Examples

Thermal wind discussion, and presentation.

Thermal advection.

Looking towards chapter 6
Tutorial on balanced flows.


Looking towards chapter 9
Tutorial on understanding flow through a jet streak
.

Week 13: 17 November

Read chapter 6, Simple Steady Motion.
We will explore the various flow regimes.
Here's the notes for the first two sections on topics of
inertial oscillations, cyclostrophic flow, geostrophic flow, and gradient wind.

Examples

Thermal wind discussion, and presentation.

Thermal advection.

Looking towards chapter 6
Tutorial on balanced flows.


Looking towards chapter 9
Tutorial on understanding flow through a jet streak
.

Winter season 500 mb surface for several years; comparing drought and more normal years.
November 1st through May 1st averages are shown for the various years. Click on image for a larger version.

Here's the 500 mb winter average for the strong El Nino year 1996 to 1997.

Here's the 500 mb winter average so far for this year.

Week 12: 10 November

Read chapter 10: Boundary layers. This is about flow and turbulence near the Earth's surface.
One homework problem for this chapter.

Then afterwards:
Read chapter 6, Simple Steady Motion.
We will explore the various flow regimes.

Examples

Large storm brewing in the Gulf of Alaska. Here's a relatively close location for monitoring the weather conditions (see wind speed and surface pressure).

Tutorial on the planetary boundary layer, in support of chapter 10.

Looking towards chapter 6
Tutorial on balanced flows.


Looking towards chapter 9
Tutorial on understanding flow through a jet streak
.

 

Week 11: 3 November

Homework due on Wednesday on Chapter 5.
Read chapter 6, Simple Steady Motion.
We will explore the various flow regimes.

Examples

Upper level symbols for the weather map homework problems.

Upper air decoding (from this site).


29 October 2014

31 October 2014

Here again is that classic low and associated cold and warm fronts.

Lake Effect Snow

Balanced Flows tutorial from Plymouth State University

 

Week 10: 27 October

Read chapter 5, fundamental forces.
We will explore the Navier Stokes equations for fluids in a rotating coordinate system, discovering approximations
to make our job easier .

Chapter 5 notes.

 

Figure 5.1 Geostrophic force balance and corresponding zonal wind in the case of a simple meridional pressure gradient for (a) the Northern and (b) the Southern Hemispheres.


Figure 5.2. Sea level pressure over Oklahoma and surrounding states on 14th February 2003 at 12Z, showing the pressure and wind reports from Denver and Dodge City, and the geostrophic force balance.

Figure 5.3. Geostrophic flow between a warm air mass and a cold air mass (a) leads to a westerly flow around the pole (b).

 

Examples:

Reynolds number discussion.

Satellite meteorology for Friday 24 Oct 2014 showing a low and associated cold and warm fronts.
Clouds as a tracer of air motions.
Complex atmospheric flow (von Karman vortex street) downwind of Guadalupe island.
Thermodynamic observations of the atmosphere.

 


Lab experiment and theory for the von Karman vortex sheet.


 

Week 9: 20 October

Read chapter 4, fundamental forces.
We will continue to look in detail at the Coriolis force to finish off this chapter, and will work on some example problems.

Chapter 4 notes.

Examples:

Coriolis force practice: land a jet on an aircraft carrier.

Balance of forces in the boundary layer simulator.

Now showing at the ATMS 317 movie theatre ...
Coriolis force movie.
Geostrophic wind movie.
Cold front in winter movie.
Warm front in winter movie.
Animation for the sun path in the sky for different locations and times.
Temperature and molecular movement movie.
Ice crystal growth effect in clouds movie.
Direct thermal circulation caused by cooling in one spot and heating in another.

Week 8: 13 October

Read chapter 4, fundamental forces.

Chapter 4 notes.

Examples:

Coriolis force practice: land a jet on an aircraft carrier.

Balance of forces in the boundary layer simulator.

Now showing at the ATMS 317 movie theatre ...
Coriolis force movie.
Geostrophic wind movie.
Cold front in winter movie.
Warm front in winter movie.
Animation for the sun path in the sky for different locations and times.
Temperature and molecular movement movie.
Ice crystal growth effect in clouds movie.
Direct thermal circulation caused by cooling in one spot and heating in another.

Week 7: 6 October

Midterm on Wednesday covering chapters 15, 1, 2, and 3.

Notes for exam.

We'll start chapter 4, fundamental forces, on Friday.

Chapter 4 notes.

Examples:

Week 6: 29 September

Continuing with chapter 3. Homework 4 and 5 are over this chapter.
A midterm exam will follow chapter 3.

Chapter 3 notes.

Examples:

Potential temperature calculator.

Wave clouds I photographed at the Richland Kennewick Pasco Airport. Click on image for larger view.
They are related to our discussion of the Brunt Vaisalla frequency and forced oscillations about
a stable layer.


Continuity equation discussion.

Week 5: 22 September

Read chapter 3. Homework 4 and 5 are over this chapter.

Chapter 3 notes.

Examples:

Potential temperature calculator.

Wave clouds I photographed at the Richland Kennewick Pasco Airport. Click on image for larger view.
They are related to our discussion of the Brunt Vaisalla frequency and forced oscillations about
a stable layer.


Continuity equation discussion.

Week 4: 15 September

Bring your laptop to class on Friday the 19th.
It would be good to put Google Earth on your laptop. It's free.
We'll do a lab based on use of the Hysplit model. The King fire lat and lon are 38.814N and 120.565W.
Try launching trajectories at 10 am and 11 am PDT on the 16th of Sept 2014.
This will build familiarity with trajectory analysis.

Read chapter 2 and look over the homework problems. An assignment is due on Friday.
We are reviewing the mathematics of fluid dynamics that we'll likely need. Notes for chapter 2.
Here's an example problem we'll go through for partial differentials, divergence, and vorticity.

A very useful, awesome site for plotting vector fields in 2 D is here.

Examples:

Barotropic and baroclinic discussed.

Hysplit model forecast for the afternoon of Tuesday, 9/16/2014.
Trajectories are launched every hour.
The 11 a.m. local time trajectory arrives in NW Reno between 4 pm and 5 pm.
Earlier trajectories pass NW of Reno.
The Washoe Zephyr circulation turns the wind towards the east.

Case study of the King fire smoke plume, 16 September 2014.


Hysplit forecast trajectories showing smoke arriving in Reno around 4 pm local time on the 16th of September. Click on image for a larger version.


UNR Cimel sunphotometer showing a short pulse of smoke at 2 pm PDT and the main plume starting to arrive at 4 pm on the 16th. Click on image for a larger version. Data from NASA AERONET.


Image of the sky looking west from the Physics building at 1:53 pm. The leading edge smoke is very 'white', likely from smoldering fire, while the browner, thicker part closer to the horizon it likely due to intense flaming fire conditions. It likely contains brown carbon aerosol (enhanced absorption at shorter wavelengths). Click for larger image.

Image of the sky later, 5:13 pm PDT, after the second pulse of smoke had arrived. West Reno is not visible anymore. A contrail passes under the sun. Click on the image for a larber version. Image of the sky at 5:32 pm PDT, showing a colorful sundog on the right due to cirrus clouds and some altocumulus clouds. Total optical depth is from gases, aerosol, and clouds. Click on image for a larger version.


MODIS instrument aboard NASA Terra satellite captured this image of the fire plume at 12:15pm PDT on 16 Sept 2014. Click on the image for a larger size.

Click here for a Reno detailed view.

MODIS instrument aboard NASA Aqua satellite captured this image of the fire plume at 1:55pm PDT on 16 Sept 2014 as the first pulse of white smoke reached Reno. Click on the image for a larger size.

Click here for a Reno detailed view.


King fire PM 2.5, black carbon, and brown carbon mass concentration estimated from the photoacoustic instruments at UNR Physics. PM2.5 was obtained from Bsca(532nm)/3.8 m^2/gram. BC from Babs(870 nm) / 5.38 m^2/gram. Brown carbon from Babs(405 nm)/11.56m^2/gram - BC. Click on the image for a larger size graph. Most of the aerosol is organic carbon. See this publication for a discussion.

 

Hysplit model backtrajectory for 100 m above the surface for the classroom.
Click on the image to see a larger version. This is an example of following along
with the air parcel:
Here is the GoogleEarth kmz file to go with it.

Here is a NAM/WRF forecast of the 850 mb surface and the temperature at this height for 15 September 2015.
Click on the image to see a larger version.

Post tropical storm Fengshen becomes a deep low and cyclone.
Click on image to see a larger version.

Unisys weather site (archived, current, and forecast).

Surface sites in and near Reno.

Discussion of the convective derivative (pretty funny and instructional at the same time).

 

Vector flow field example problem

 

Fire Case Study 15 September to 16 September 2014. Click on images to see larger versions.

Hysplit model forward trajectory model

Photo from Physics roof

Image using neutral density filter to block most of the direct sunlight.

Atmospheric Optical Depth from the UNR Cimel sunphotometer showing effect of aerosol from the fire.

 

Week 3: 8 September

Bring your laptop to class on Wednesday if you can. We'll look at some websites for making maps (related to the HW).

Talk about and use precipitable water as a tool for identifying air masses.
Integrate water vapor density with height and set equal to the height of liquid water needed to give the same mass per unit area.

Look at soundings for Reno for July 2014 to see the different precipitable water values.

Look at AERONET sunphotometery as a method to get precipitable water.

Use the reanalysis data processor from Plymouth to look at the CONUS precipitable water for 12 Z November 5th 2002 for problem 1.2.

Plymouth State Univ. reanalysis data processor
NOAA Surface Analysis Archive
NOAA Reanalysis Data Site (useful to use McIdas to look at it.)
Good boundaries to use for CONUS maps: Longitude: 136W to 60W. Latitude: 20N to 53N.

Read chapter 2. We'll start on it this week as well. Notes for chapter 2.

Homework 2 due on Friday.
Isoplething guide for HW2, drawing isotherms on surface maps.

Chapter 1 presentation.

 

Examples:

Weather of 8 September 2014 involves a low to our west and flow to the north of moisture from decaying hurricane Norbert.


Image from the Reno NWS office.

Radar showing precipitation patterns.

IR view of cloud and transport.

Upper level station values.

Week 2: 2 September

Homework 1 due on Wednesday.
Chapter 1 presentation.

Homework 2 has been posted. It's over chapter 1 material.

Week 1: 25 August

Three places to learn about what is going on in this class:
Daily Notes (here).
Calendar.
Homework.

Syllabus.

We will begin with chapter 15 (here is a presentation on it). This chapter gives an overview of global atmospheric circulation.
Then we will do chapters 1 through 6, followed by chapter 9. The remaining chapters will be covered as time permits.

 

Examples:
850 mb level in July from 2011 to 2014.
500 mb level in July from 2011 to 2014.

Dust circulation near the equator and Africa from the NASA/GMAO model output.

weather

Fluid flow demonstrations

ALL WILL WORK TOGETHER FOR A COMMON PURPOSE: To study the atmosphere from many perspectives!