ATMS 360 Homework and Course Deliverables (return to main page)
[How to write lab report]

Possible assignment to calculate the response time of the Physics building:

PM measurements inside and outside the Physics building on 1 Sept 2021, with an abrupt change that allows for observation of the response time.

Image


Click for larger version.

Data from inside and outside the building for Sept 1st, 2021.

 

 

Assignment 10: This assignment will done in class as much as possible.

Title: Gravity wave clouds in the atmosphere downwind of the Sierra Nevada mountain range.

Study using balloon sounding radiosonde and satellite measurements.

Turn in this homework assignment through webCampus, prepared using Powerpoint.
Presentations will be on the day of the final exam.
Each presentation must be less than 10 minutes long.

Observe gravity wave clouds in the atmosphere and perhaps problems with radiosonde measurements.

FUTURE CHANGES TO THIS ASSIGNMENT:
1. Gather both the Terra (morning) and Aqua (afternoon) images to look at the evolution of the wave cloud during the day.
2. Gather both the morning (12Z on the day of) and afternoon (0Z on the day after, making it 4 pm local time on the day of) to look at the evolution of the atmosphere during the day.
3. Encourage cloud type identification from the combination of satellite imagery and soundings.
4. Plot the vertical distribution of potential temperature and interpret.

Purpose:
1.
Learn about radiosonde (balloon soundings of the atmosphere), satellite imagery, and an important cloud type for us in Reno, wave clouds.
2. Help diagnose issues with radiosondes when they exit clouds after wetting the temperature sensor. Evaporative cooling of cloud water from the sensor gives abnormally low temperatures.

Deliverables: A Powerpoint presentation with a minimum of 3 slides as follows. (Each student has been assigned a year to look for data. See the Daily Notes page for your year.)

Slide 1: NASA MODIS/AQUA satellite image showing wave clouds downwind of the Sierra Nevada Mountains.
Example
image from 25 November 2020 at 20z.

Slide 2: Atmospheric sounding image of air and dewpoint temperature and winds. Circle the likely layer near 700 mb associated with the wavecloud.
Example
from 26 Nov 2020 at 0z. Soundings can be obtained here.

Slide 3: Screen shot of the atmospheric sounding data. Highlight the data near where the likely level of the wavecloud is located.
Note where the RELH (relative humidity) is high and if THTA (potential temperature) decreases with height,
possibly due to evaporative cooling of cloud water from the temperature sensor.
Example from 26 Nov 2020 at 0z. Soundings can be obtained here.

Students may repeat these three slides for different days within their year, though each presentation must be 10 minutes or less.


Resources and Related Information:
Photograph of a wavecloud from the top of the Physics building at UNR on the 7th of April 2021 at around 4 pm local time.
Photograph by Ally of the same cloud earlier in the day.
Satellite imagery of the wave clouds on the 7th of April 2021. Faster and longer duration version.
Sounding for the 7th of April 2021 at 12Z.
Sad sounding for the 8th of April 2021 at 0Z.
NOAA Weather and Climate Toolkit for obtaining radar data and satellite imagery in case you want to get your own geostationary satellite images and movies.
Afternoon NASA/AQUA/MODIS satellite imagery for the southwest US for April 17th, 2003-2021 to show regularity of the events.
GOES satellite imagery for 11/25/2020 LST showing wave clouds.
Low resolution and high resolution soundings for 0z 11/26/2020.


Balloon-based sounding presentation.
Waves in the atmosphere presentation. See especially slides 6-28.

Slide Mountain weather station data relevant to observing the atmopsheric pressure near the crest of the Sierra Nevada Mountains nearby Reno.
Slide mountain weather station observed on Google Earth Online.

Radiosonde discussion.
See https://www.weather.gov/upperair/Study2 for radiosonde errors discussion.
See https://en.wikipedia.org/wiki/Lee_wave for lee wave discussion.
Chase gravity waves to improve weather and climate models.

 

 

 


Assignment 9

Title: Meteorology and Air Quality of January 2021 at UNR and Reno

Deliverables as described below:
1. A report with references. See section 8 below.
2. Presentation for your specific case study. See sections 7 and 9 below.

Purpose:
Learn about typical and anomalous air quality and meteorology in Reno/UNR for January 2021.
Work with raw data to get a feel for time alignment issues, and use of Excel data base functions for making diurnal averages (24 hour averages).
Learn how to do a case study for diagnosing and understanding specific events.
Learn about and work with data from the sonic anemometer, low cost air quality sensor SPS30, and the BAM1020 instrument used for PM measurements in cities to regulate air quality.
Learn how to use HYSPLIT back trajectory analysis and Google Earth to determine likely source regions for windblown dust.
Learn about remote sensing with the Cimel and MFRSR sunphotometer and spectral irradiance for obtaining column aerosol optical depth (AOD), with an eye towards satellite remote sensing of AOD.
Learn how to use radiosonde balloon soundings of the atmosphere for air pollution transport applications.

Discussion:
We will work on this assigment as a group, and outside of class.
For background, we routinely measure local and column properties of the atmosphere from the roof of the Physics building, with standard and custom instruments of our own manufacture.
Reno also has the National Weather Service and many weather stations at various elevations.
Our unique location results in brilliantly clear days, inversions with air quality issues, and days with windblown dust arriving from nearby dry lake beds.

Notes:
Please be sure to reach out to me during online class or afterwards if you are having issues.
We will make sure everyone is caught up and complete in working through this assignment.
Feel free to share your skills and expertise with the everyone.

Required and Recommended Software:
1. Excel and Word. Available for students and faculty here. Sign in with your UNR netID and download Office to your computer. We will import data using the text wizard: Excel:File:Options, then check this box.
2. Google Earth available here.
3. Optional: Anaconda distribution of Python available here. We will likely use 'Spider' to edit and run Python programs.
4. You can use Matlab or any other program if you want, for data and graphical analysis rather than Excel.

1. Big Picture.

Reno is a high desert city with aerosol from both local and distant sources. This lab will take a glimpse at Reno aerosol, both at the surface as measured in situ, and in whole atmospheric column as measured with ground based remote sensing instruments, the Cimel and MFRSR . Click images for larger version.

 

2. Here is a look at January 2021 to act as motivation for this assignment.

A look at January 2021 Click images for larger versions.


Measurement were obtained with the SPS30 low cost air quality sensor described below.


Light interaction with aerosol, on why dust is visible. From this paper on the subject.

Headlines on January 19, 2021:

"Dust reaching Carson City area from Black Rock Desert prompts weather service advisory"


The author also mentions the Carson Sink as a potential source of dust.

3. METEOROLOGY AND SATELLITE IMAGERY OF THE EVENT ON JANUARY 19TH 2021 16:00 LST.

Meteorology for the 0Z January 20th and the peak in PM.
GFS model winds and sea level pressure. View various pressure levels.
NASA Worldview true color image from the MODIS sensor on the the AQUA satellite for 13:30 LST on January 19th, 2021. Be sure to zoom the Northwestern Nevada area to see the desert dust. Also look at the MODIS/Terra image for the cloud hole off the coast of Baja California.
Reno radiosonde measurement at 0Z January 20th.
High resolution version of the radiosonde measurement at 0Z January 20th.
Looking towards Reno from the East North East Google Earth online.

4. IN SITU MEASUREMENTS WITH UNR INSTRUMENTS AND THEIR DATA FOR THIS STUDY:

A. Sonic Anemometer: Click for larger images

Broad view of the sonic anemometer and others.

Close up of the sonic anemometer.
Documentation:
Sonic anemometer manual.
Presentation 1, Presention 2, Presentations 3.
Gill manufacturer of sonic anemometers.
RM Young manufacturer of sonic anemometers.

Sonic data for January 2021:
Right click on link and save it to disk.

(Note the wind directions used for the sonic anemometer)

Same data compressed in a zip file.

 

B. PM2.5 and PM10 from the BAM1020 instrument often used by EPA for real time PM measurements in cities.Click Images for larger version.

Beta Attenuation Monitor (BAM) Inlets for PM2.5 and PM10. PM2.5 has a cyclone to remove aerosol larger than 2.5 microns in diameter. (Article on cyclones).

How a cyclone works to take out larger aerosol by impaction and vortex flow. From this article on bioaerosol detection.

The two BAM instruments at UNR, inside the telescope dome.


Inside view of the BAM 1020.


Detailed view of the radioactive C14 source for the BAM detection scheme.


Beta Attenuation Monitor (BAM) theory of operation, from the manual.

Documentation:
BAM1020 Manual.

Calculate the speed of 49 KV electrons from the radioactive source.

About radioactive decay.

BAM Data for January 2021:
Right click on link and save it to disk.

BAM Zero Filter Data for 7-12 November 2019:
Excel spreadsheet (thanks Sam Taylor).

HOURLY MEASUREMENTS:
a. PM2.5, PM10, and PMCourse=PM10-PM2.5.
b. Ambient temperature.
c. Air temperature and relative humidity in the instrument.
d. Volume of air sample during hour.

 

C. Low Cost Air Quality Sensor for Aerosol Size Distribution and PM1, PM2.5, and PM10 measurements. (SPS30)

SPS 30 mounted near the photoacoustic instrument inlet on the 4th floor of Leifson Physics roof area.

SPS 30 sensor in my office used for indoor air quality measurements.


Detailed view of the interior of the SPS30 particle sensor.
MINUTE MEASUREMENTS INCLUDE:
a. Aerosol size distribution from 0.3 um to 10 um in 5 bins.
b. PM1, PM2.5, PM4, and PM10.
c. Ambient temperature and relative humidity.

PROPERTIES CALCULATED FROM THE SIZE DISTRIBUTION MEASUREMENTS:

a. PM1, PM2.5, and PM10 (to evaluate reported values).
b. Aerosol light scattering coefficient, and asymmetry parameter at 19 wavelengths from the UV to the near IR assuming spherical particles, for PM1, PM2.5, and PM10 size cuts.

Documentation:
Data sheet for the SPS30
How to install the SPS30
Our website with SPS30 software
New and Important: SPS30 Application note and description of measurement method.
Related Sensor Network Based On The PMS5003, a Similar Sensor:
Purple air particulate network.
Reno Purple Air sensor measurements.

SPS30 Data for January 2021:
Right click on link and save. 1 Min Average Data.
Compressed zip file for smaller download.

SPS30 Data Time Averaged to BAM Time

5. GROUND-BASED ATMOSPHERIC REMOTE SENSING MEASUREMENTS FROM UNR INSTRUMENTS AND THEIR DATA FOR THIS STUDY:

A. Multifilter Rotating Shadowband Radiometer (MFRSR) Instrument for Solar Spectral Irradiance at 7 Wavelengths, for Both Total and Diffuse Radiation

Blow up of the MFRSR, from the MFRSR Manual.

View of the MFRSR mounted on the roof of the Physics building. It is vital that the diffuser is horizontal, and that the motor points due to geographic north.


View of our MFRSR as mounted on the roof of Physics. The shadow band is show blocking the direct sunlight to provide only the diffuse radiation. The instrument measures total and diffuse radiation, and direct is obtained from direct=total-diffuse.


MFRSR electronics/control box. (Old school but effective.)
Documentation:
MFRSR Handbook.
Manuscript describing measurements from the MFRSR.

MFRSR DATA FOR JANUARY 2021:
Total, diffuse, and direct radiation.
Aerosol optical depth obtained from direction radiation.

 

B. Cimel sunphotometer as part of NASAs AERONET Network
 
Documentation:
Video of the sunphotometer in operation.
Sunphotometer presentation by Chris.
Aeronet network description.
Cimel Data Portal:

Summary of Data For January 2021:
Sonic anemometer data. (right click and save link as a file on your computer).
Beta Attenuation Monitor (BAM). Right click on link and save it to disk.
SPS30 Low Cost Air Quality Sensor. Right click on link and save.
SPS30 data time averaged to the same intervals as the BAM data.
UNR Cimel Sunphotometer data portal.

Summary of Resources and References:
In situ light scattering and absorption theory and measurements: (Not used in this study, but educational).
Light scattering by wind blown dust.
Photoacoustic instrument manual for aerosol light scattering and absorption measurements.
Photoacoustic optical properties at UV, VIS, and near IR wavelengths for laboratory generated and winter time ambient urban aerosols.

Sonic Anemometer:
Sonic anemometer manual.
Presentations on sonic theory and student projects. Presentation 1, Presention 2, Presentations 3.
Gill manufacturer of sonic anemometers.
RM Young manufacturer of sonic anemometers.

Beta Attenuation Monitor (BAM1020):
BAM1020 Manual.
How a cyclone works to take out larger aerosol by impaction and vortex flow. From this article on bioaerosol detection.
Calculate the speed of 49 KV electrons from the radioactive source.
About radioactive decay.
Carbon 14 discussion.

SPS30 Low Cost Air Quality Sensor:
Data sheet describing the SPS30
How to install the SPS30
Article on performance of low cost air quality sensors, including the SPS30.
Our website with SPS30 software
Article discussing 'machine learning' to improve the response to PM Coarse aerosol.
Related Sensor Network Based On The PMS5003, a Similar Sensor to the SPS30.
New and Important: SPS30 Application note and description of measurement method.

MFRSR Remote Sensing Instrument
MFRSR handbook.
Manuscript on MFRSR measurements.

Sunphotometer theory for remotely sensing column aerosol optical depth.
Sun photometer theory.
Our sunphotometer analysis website (air mass and Rayleigh optical depth calculator based on Perl language, here's the source code).

Articles describing aerosol and health.
Dissertation (see Figure 6).
Journal article (see Figure 2).

EPA Criteria Pollutants.
Criteria Air Pollutants and National Air Quality Standards
.

Hysplit Air Trajectory Analysis.
Hysplit air trajectory model presentation.
Run the HYSPLIT model.

The Physics building coordinates are Latitude= 39.540980° Longitude=-119.814090° .

Meteorology of smoke plumes.
Lapse rate influence on smoke plume dispersion.
Example of smoky layer transporting across the Pacific Ocean to the US from fires in Russia.

Related References:
Satellite Remote Sensing of Particulate Pollution from Space: Have We Reached the Promised Land?
Combine the ideas of the next two papers to estimate potential hygroscopic growth of aerosol based on RH and aerosol chemistry.
Accuracy of near surface aerosol extinction determined from columnar aerosol optical depth measurements in Reno, NV, USA, especially Fig 4.
Revised Algorithm for Estimating Light Extinction from IMPROVE Particle Speciation Data
Photoacoustic analysis of combustion aerosol presentation, including a world tour.
Air pollution and meteorology in Russia: similar to our case study.
Mexico City aerosol 2009 paper.
Mexico City and Queretaro 2019 paper.
Per capita air pollution paper.
Reno winter time air pollution paper.
Northeast Colorado air pollution paper with meteorological impacts on PM2.5 and PMCoarse concentrations.
Hysplit air trajectory model.
Applications of air trajectory analysis review article.
Infrared radiation model for clear skies, and calculation of cloud effect.
Beijing fine and coarse mode aerosol composition measurements.
EPA Criteria Air Pollutants and National Air Quality Standards.
Related Sensor Network Based On The PMS5003, a Similar Sensor to the SPS30:

6. Data analysis and visualization we will do in class.

a. Time series analysis for the entire month.

Read in sonic data, SPS30 data, and BAM data to an Excel spreadsheet.
Make a time and date column for each data set as the sum of the separate time and date columns.
Time align the data (get rid of data with time stamps on the same for both. Sometimes there is missing data).
Calculate the wind speed and direction from the sonic data. (Note the directions used for the sonic). Wind Direction=ATAN2(-E2,-D2)*180/PI()+180, Wind Speed==SQRT(E2^2+D2^2)/10, D2 is U; E2 is V.
Make a time series graph of SPS30 PM2.5 and overlay BAM PM2.5. Note the high and low values of PM2.5. Note the level of agreement of disagreement of PM2.5 by these instruments.
Make a time series graph of SPS30 PMCoarse and overlay BAM PMCoarse. Note the high and low values of PMCoarse. Note the level of agreement of disagreement of PMCoarse by these instruments.
Make a scatter plot of SPS30 PM2.5 on the y axis, and sonic wind speed on the x axis. Does wind speed seem to predict PM2.5 levels?

Optional Analysis (not required): Perform diurnal averages (typical 24 hour day in Reno) for [overlay wind speed, kinetic energy, turbulent kinetic energy,] [overlay sonic temperature, pressure,] [overlay SPS30 pm2.5, SPS30 PMCoarse, BAM PM2.5, BAM PMCoarse.]
[overlay is to put these on the same graph].

b. Case study analysis for January 19th 2021.

Make a time series of PM2.5 and PMcoarse for the 19th of January to see the large change that happened with the arrival of the dust storm.
Make a time series bubble graph of wind direction for Jan 19th. Make bubble size the wind speed to understand when the wind is greatest and lowest, and what direction it is coming from.
Get the Cimel AOD graph for Jan 19th, and any retrieved size distributions to see if there is a correspondence with PM2.5.
Find the time of peak PM2.5. Do Hysplit back trajectory analysis to the Physics building roof (about 25 meters above ground level) to find out where the aerosol was likely coming from for this day/peak.
Use Google Earth for displaying back trajectories and see if they 'explain' where the aerosol came from. Building coordinates are Latitude= 39.540980° Longitude=-119.814090° .

Hysplit air trajectory model presentation.

7. Data analysis and visualization on your own.

Repeat the steps in part b for another day and time of interest.
You could choose a really clean time, or polluted time, on a different day, to see if you can interpret the aerosol pollution or lack thereof.
Ok your time and date for your study with me so that each student looks at a different case study.

8. Write your report as we have been doing all semester. Use lab report format.
Describe all of the instruments in your report and present your data analysis.

9. Prepare a presentation for your case study in part 7.


Appendix 1. Example of Science Questions
For Case Studies Like This


1. Is the surface aerosol size and composition affected by updrafts and downdrafts at the surface and in the column?
Associated questions:
a. Are their persistent and strong updrafts and downdrafts at our site? (use the vertical component of wind from the sonic anemometer to answer this question.)
b. What time of day are they most noticed?
c. How do clouds affect the presence of updrafts and downdrafts?
INSTRUMENTS
i. SPS30 aerosol sensor especially for PM2.5 (4 seconds and 1 minute) Surface temperature, dewpoint, and RH (4 seconds and 1 minute)
ii. Sonic anemometer on the roof (5 Hz and 1 minute)
iii. MFRSR Solar spectral solar irradiance with shadowband for direct and diffuse radiation.


2. Can the surface PM2.5, PM10, and PMCOARSE (PM10-PM2.5) be 'explained' by surface meteorological conditions, wind speed, direction, temperature, humidity, pressure, at the surface and boundary layer height determination?
Associated Questions
a. Does the SPS30 PM2.5 and PM10 agree with the Beta Attenuation (BAM) hourly PM2.5, PM10, and PMCOARSE well enough that we can use them interchangeably? (so far we see that PM2.5 is ok).
The SPS30 has 4 second data while the BAM data is hourly. It's useful to have fast measurements but only if they are actually reasonable.
INSTRUMENTS
i. BAM1020 Beta Attenuation instrument
ii. SPS30 PM sensor
iii. National Weather Service Balloon soundings (boundary layer height, time/height graphs of column relative humidity, and aerosol hygroscopic growth dependent on aerosol chemistry).
PARTIAL LIST OF REFERENCES (student can find others)
Black carbon aerosol concentration in five cities and its scaling with city population.
Photoacoustic optical properties at UV, VIS, and near IR wavelengths for laboratory generated and winter time ambient urban aerosols.
See figure 4 of Accuracy of near surface aerosol extinction determined from columnar aerosol optical depth measurements in Reno, NV, USA.

3. Is the surface aerosol optical properties measured with photoacoustic instruments and their nephelometers 'the same as' the column optical properties?
This is a central assumption of using satellite remotely sensed aerosol optical depth for surface aerosol pollution determination.

Associated Questions
Can the column aerosol optical depth be used with the surface extinction coefficient to obtain the atmospheric boundary layer height?
INSTRUMENTS
i. Cimel sunphotometer level 1.5 data (cloud screened)
ii. MFRSR aerosol optical depth measurements
iii. 405 nm photoacoustic instrument data averaged to 30 minutes or ?
iv. 532 nm photoacoustic instrument data similarly averaged.
v. Perhaps 660 nm data
vi. PAX 870 nm data as it becomes available.
iv. National Weather Service Balloon soundings (boundary layer height, time/height graphs of column relative humidity, and aerosol hygroscopic growth dependent on aerosol chemistry, and downwelling spectral IR based on the FASTCODE model).
PARTIAL LIST OF REFERENCES (students can find others)
Satellite Remote Sensing of Particulate Pollution from Space: Have We Reached the Promised Land?
Photoacoustic optical properties at UV, VIS, and near IR wavelengths for laboratory generated and winter time ambient urban aerosols.
Combine the ideas of the next two papers to estimate potential hygroscopic growth of aerosol based on RH and aerosol chemistry.
Accuracy of near surface aerosol extinction determined from columnar aerosol optical depth measurements in Reno, NV, USA, especially Fig 4.
Revised Algorithm for Estimating Light Extinction from IMPROVE Particle Speciation Data

 

 


Assignment 7
Lapse rates in Reno.

The goal is to become familiar with near surface weather station data and its importance.
Another goal is to practice writing lab reports.

We will compare and contrast temperature inversions in the first 150 meters of the atmosphere above the surface in the month of August 2020 with February 2020.
We will do the analysis in class for February 2020 and August 2020 will be done as homework.
It will be good to do the August 2020 analysis immediately after we do the February 2020 analysis in class.

We will obtain and use data from the UNR and Desert Research Institute (DRI) weather stations and discuss how to do so.
DRI is close to TMCC and the National Weather Service office, north east of UNR.

We will use time series and/or scatter plots of relevant meteorological data (wind speed, solar and IR radiation, etc) that helps
explain inversions.


Calculate the average fraction of the day for inversions during these months.
Prepare and discuss the histogram of temperature inversion.
Your discussion could include a comparison of the histogram for February 2020 that we will work on in class.

Deliverables:
1. Google Earth image showing the location of the DRI and UNR weather stations and the overall sense of topography.
The GPS coordinates of the sites are in the table below under site description.
Here's a calculator to convert from minutes and seconds to decimal degrees for the DRI site.
2. Time series overlay graphs for UNR and DRI for temperature and pressure that scope the data. (August 2020 data)
3. Diurnally averaged overlay graphs for UNR to see what an average day looks like (August 2020 data) [pressure:wind, pressure:solar, wind:solar, temperature:solar, lapse rate:solar] Here's an example from February 2020.
4. Time series graph of lapse rate calculated from the UNR and DRI weather station data. (August 2020 data).
5. Scatter plot with wind on the horizontal axis, and lapse rate on the vertical axis to explore their relationship (peak wind drives August towards the dry adiabatic lapse rate, and higher rates are seen in the a.m.) Both months. (Future assignments).
6 Histograms of lapse rate for February 2020 and August 2020 to facilitate comparison.
7. Use lab report format.

Resources
Install Google Earth, or use it with a browser.
Install Excel and Microsoft Word.
Install the Endnote plugin into Microsoft Word to use in managing your references, and use of Web Of Science to obtain them.
Automated weather station discussion and one company that sells them.
Presentation discussing a common type of temperature sensor element, thermistors.
Aerosol pollution in Reno during 2020 to get a feel for seasonality and special events, like the massive wild fires we had in 2020. Image and spreadsheet versions.
Archived meteorological data for use in understanding specific events.
Reno as a valley subject to cold pools.
Lapse rate definition.
Notes for assignment 7 (OneNote format).

All of the Western Regional Climate Center Weather Sites click here  
LOCAL WEATHER STATION DATA MANAGED BY THE WESTERN REGIONAL CLIMATE CENTER AT DRI PASSWORD IS wrcc14 SITE DESCRIPTION Current Data Graphs to see what's going on
UNR Weather Station on Valley Road

click here
Accurate Coordinates:
39.53918 N, 119.80476 W

Photograph and Video

click here
DRI Weather Station

click here
Coordinates:
39.57083 N, 119.235 W

click here
Slide Mountain Weather Station click here click here



Assignment 6

The goal is to develop skill in working with meteorological radar data.
This assignment works with precipitation and Doppler data from NEXRAD radar.
Practice giving presentations of meteorological data.

Deliverables:
1. Presentation turned in through webCampus. (50 points possible)
2. Present your presentation to the class. (50 points possible)

Choose a specific radar for your study. Here's where you choose the radar.
Try to choose a radar location and time that is unique.
You can look over the composite radar data throughout the country to get an idea of where and when to choose a location.
Find the coordinates of your radar.

Presentation Contents:
1. Put your radar coordinates into Google Earth and make an image of the location of the radar.
2. Get a GIF movie of at least 6 images of base reflectivity data from your radar a day when precipitation is present.
3. Get a base velocity image (or GIF movie) of base velocity for the same time.

In your presentation:
Discuss the location of your radar, in particular, any challenges that come about due to location.
Discuss the dbZ level of your base reflectivity image. Is it large or small?
Discuss your base velocity image, interpreting wind direction and speed.
You can add other related meteorological data to enhance your presentation.

Resources
Install Google Earth, or use it with a browser.
Install Powerpoint or use it from a browser, or use Google Docs, or Pages on the Mac.
It may be useful to also explore the National Weather Service radar site.

 

 

Assignment 5

The goal of this quick-study style lab is to become familiar with meteorological radar used to detect precipitation.
Examples are on this page for composite reflectivity
and for the Reno NWS dual polarization radar measurements.
Example of Doppler image for Des Moines Iowa.

Submission is through webcampus.. Copy these questions to MS word and work on them.
Be sure to give your sources for answers. We'll go through this in class.

Basics:
1. What diameter range are raindrops?
2. What is the shape of raindrops?
3. Why don't raindrops get arbitrarily large?

Local Rain Measurements:
4. What is the rainfall rate equation?
5. How does a simple rain gauge work?
6. How does a tipping bucket rain gauge measure rain?
7. How does a disdrometer work?

Weather Radar.
Weather radar presentation as powerpoint and as a pdf document for understanding radar and dbZ.

8. What is the name of weather radars used by the National Weather Service?
9. What wavelength range used by this radar?
10. Briefly, how does radar work to measure rain?
11. Calculate the size parameter x=2 pi * Raindrop Radius / radar wavelength.
12. What 'radiation regime' is the size parameter of equation 11? Note that it is the same radiation regime that gives rise to the blue sky on a clear day. Note.
13. What is the basic relationship for radar backscattering in terms of number of raindrops per volume, back scattering strength, droplet diameter D, and radar wavelength lambda? Note.
14. Why must the radar be empirically calibrated given question 13, and question 4?
15. How does Doppler radar work? What can be detected with it?
16. How does dual polarization radar work, and what can be detected with it?

Resources:

National Weather Service discussion of weather radar.
Understanding radar discussion from the weather underground.

 


Assignment 4
Online (see webCampus) precipitation estimates.

Purpose: Become familiar with precipitation estimate measurements.

Assignment 3 Online (see webCampus) measurement of atmospheric temperature.

Purpose: Become familiar with atmospheric temperature measurements.

Assignment 2 Online (see webCampus) overview of Atmospheric Instrumentation.

Purpose: Broad overview of atmospheric instrumentation measurements.
This is an online homework assignment and is described on webCampus.

Assignment 1 Online (see webCampus) atmospheric radar measurements.



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