# How to use and interpret Doppler weather radar

Save this PDF as:

Size: px
Start display at page:

## Transcription

1 How to use and interpret Doppler weather radar A novice guide to understanding the principles of radar and how to use base reflectivity and base velocity to show that more than rain and wind is occurring Jeff Duda 1

4 Fundamentals of radar The weather radar you see on your local TV news program, The Weather Channel, or other news channel is Doppler radar. Doppler radar emits beams (pulses) of microwave energy from a transmitter into the atmosphere (see the figure below for a diagram of the electromagnetic spectrum). When these beams collide with objects in the atmosphere such as raindrops, hail stones, snowflakes, cloud droplets, birds, insects, dust particles, trees, and even the ground, some of the energy bounces back towards the radar. A receiver on the radar then collects the reflected energy and displays it in different ways. The electromagnetic spectrum. The microwave region of the spectrum is towards the left, where wavelengths are relatively longer and frequencies lower. Image courtesy of Wikipedia the electromagnetic spectrum 4

12 Base reflectivity Base reflectivity is a radar product that displays the amount of power returned to the radar after it has reflected off particles in the atmosphere. The actual amount of energy returned is not displayed. What is displayed is a term called reflectivity (hence why this product is named base reflectivity), and is measured in decibels (dbz). A decibel is a measure of the energy transmitted by a wave, or a measure of the amplitude of a wave. For Base reflectivity. An example base reflectivity image from the Little Rock, AK (KLZK) is shown. Note the information that is given in the title above the image. Also note the scale on the right, indicating the strength of returns to the radar, measured in decibels (dbz). The orange and red colors indicate a line of thunderstorms is currently moving across Arkansas. Image courtesy of UCAR: 12

13 reference, sound waves are also measured in decibels. The usual range of reflectivity that is displayed by this product is between 0 dbz and 80 dbz, with 0 dbz indicating very little return of energy and 80 dbz indicating extremely intense returned energy, usually a value never reached in meteorological scenarios. Note that reflectivity values can be negative since the reflectivity scale is actually a logarithmic scale, which means the numbers on the scale are actually powers of dbz actually means 10 0, or 1 of some other measurement in the processing of returned energy. Although radar scans 360 of the atmosphere at many tilts, only the lowest one (which is usually 0.5 above horizontal) is displayed. This gives the product name the base prefix, and means the same thing in all other products. Also note that the value of reflectivity in a bin of data is actually the average of all the reflectivity values detected within that bin (there will almost always be multiple targets that reflected the energy within the areal space of one bin, and they won t all reflect the same amount of energy). This is most useful to know when dealing with a tight reflectivity gradient, or large change of reflectivity over a distance of a few bins, and is most obvious at large distances from the radar site. Interesting things that can be seen with base reflectivity Base reflecitivity is interesting in the sense that it will show echoes whenever energy from the radar beam bounces back to it. Anything in the atmosphere that can reflect microwave energy will cause echoes to appear on a radar display. Many times, these echoes are not precipitation, but are meteorological in nature. If base reflectivity shows echoes that are not meteorological in nature, the echoes are called anomalous propagation, which is discussed later. Frequently, a boundary between warm, moist air, and cool, dry air causes reflection of a wave. This boundary will be seen as a very narrow line of light reflectivity. This boundary can be a warm or cold front, a dryline, or outflow boundary from thunderstorms. When the atmosphere is unstable and thunderstorms are likely to form, it is common to see storms form directly on boundaries. 13

15 A three-body scatter spike. An example of a three-body scatter spike is shown from the Green Bay, WI (KGRB) radar using the Gibson Ridge software. The TBSS is evident as the streak of low reflectivity extending past the storm in the image along five radials. The white bins in the storm show reflectivity values of over 70 dbz, a strong indication of large hail in the storm. The TBSS is an even stronger indicator that large hail is present. Although this particular scan is at 8.0, TBSSs can occur at any elevation angle. The 8.0 scan showed this example the best. 15

16 Bright banding Bright banding is a region of relatively intense reflectivity found in an area where frozen precipitation is likely occurring, or along a boundary between frozen and liquid precipitation. The high reflectivity is not an indication of very heavy precipitation falling, but is rather an indication of liquid coating on frozen precipitation. Liquid water reflects microwave energy much better than does frozen water. At the boundary between frozen and liquid precipitation, there will be a mix of both phases of water. The liquid coating on the frozen particles will make the particles appear much larger to the radar due to reflecting much more energy. Therefore, the reflectivity will be much higher where this is occurring. The difference in reflective abilities of liquid and frozen water enables an observer of radar to determine where frozen and liquid precipitation are occurring. Frozen precipitation will appear much smoother, with very small reflectivity gradients and overall Bright banding. Shown is a base reflectivity image using the Gibson Ridge software from the Louisville, KY (KLVX) radar site. Note the reflectivity scale on the left, and note that smoothing has been applied to this image. Bright banding is occurring just to the northeast of the radar site, indicated by the orange and red colored reflectivity. Close observation of this image would reveal that the frozen precipitation to the northwest of the bright banding region appears smoother (in a different sense than due to the smoothing algorithm) in the image than the liquid precipitation to the southeast. It is unlikely that precipitation heavy enough to reflect that much energy is falling in the bright banding region. The high reflectivity is due to bright banding. 16

17 lower reflectivity than will liquid precipitation, which will appear more coarse with higher gradients and higher reflectivity. This same principle is also used to explain why hail appears as very high values of reflectivity on radar. In fact, reflectivity values above 60 dbz are usually an indication that hail, or a mixture of heavy rain and hail, is being detected. Reflectivity values greater than 70 dbz likely indicate large hail is being detected. Hail grows by collecting liquid water on the surface of an already existing hail stone. The liquid water then freezes and adds a layer to the stone. The liquid water coating the hail stone reflects a very large amount of energy emitted by radar and results in very high values of reflectivity showing up on radar. High reflectivity. Shown is a base reflectivity image from the Jackson, MS (KDGX) radar using the Gibson Ridge software. Note the reflectivity scale on the left. The high reflectivity values (>60 dbz) shown in the pink color are likely indicators of hail, or a mixture of very heavy rain and hail. The liquid coating on hailstones causes them to reflect more of the energy in the radar beam back to the radar, resulting in higher reflectivity values there. 17

20 Wind shear on base velocity. A base velocity image from the Green Bay, WI (KGRB) radar site is shown using the Gibson Ridge software. A clockwise turning of the winds with height is evident as the curving of the zero isodop as one moves away from the radar site. The figure below shows the same product and time, but using the 4.5 elevation scan to show how much more clearly wind shear appears on a more sloped plane of elevation (due to the higher tilt angle). 20

21 When a front is approaching the radar, you can determine where it is and see the change of wind across the front as long as enough echoes are visible. Consider the example shown in the figure below. Frontal passage on base velocity. A base velocity image from the Bismarck, ND (KBIS) radar is shown using the Java NEXRAD Viewer. Note the information given on the right, including the scale, which uses slightly different colors than the typical red/green pattern. Use the definition of negative and positive values of velocity to determine that winds to the southeast and northwest of the radar site (towards the center of the image where the radials converge) are towards the radar and winds to the northeast and southwest of the radar site are away from the radar. This may seem confusing at first, but find the zero isodop running nearly due west to east across the image also. This indicates that winds are south to north to the east of the radar site and north to south to the west of the radar site. There appears to be a boundary across which wind directions drastically change. It is oriented south-southwest to northnortheast and passes almost directly over the site. It is a cold front! 21

24 Range folding. A base velocity image from the Memphis, TN (KNQA) radar site is shown using the Gibson Ridge software. Purple haze is apparent towards the outer edges of the radar s range. The PRF of the Memphis radar was such that pulses that traveled into the purple region did not make it back before the next pulse was emitted. All of the echoes that are colored purple are range folded, and nothing can be said about what is happening with the winds in this region. The first base velocity image shown at the beginning of the section also contained purple haze. 24

25 This guide will now move into some more advanced topics. The more advanced topics include a discussion on volume coverage patterns and anomalous propagation. Volume coverage patterns (VCPs) By now you may have noticed the abbreviation VCP with a number next to it on some radar displays. VCP stands for volume coverage pattern, and describes the pattern by which the radar scans the atmosphere. Radar can scan at a number of different elevation angles above the horizontal. As you learned about base reflectivity, you learned that product uses the lowest elevation angle, 0.5. Depending on the VCP, the radar may scan at up to 14 different elevation angles. VCPs are labeled as a two or three-digit number, but the digits can only be 1, 2, or 3. The first number denotes whether the pattern is clear-air mode or precipitation mode. Consult the table below for a better description of the VCPs. For reference, a volume scan is a scan of all elevation angles together as a set. First digit Second digit Table of volume coverage patterns. The various VCPs are described. VCP Clear-air mode Clear-air mode Precipitation mode Precipitation mode Precipitation mode Special characteristic or used for Lower PRF than VCP 32 Higher PRF than VCP 31 Lighter or distant precipitation Number of elevation angles Length of time for one complete volume scan 5 10 minutes 5 10 minutes 9 6 minutes Thunderstorms minutes Works the same as VCP 11 but uses denser vertical sampling in the lowest few elevation angles minutes The three-digit VCPs are 121, 211, 212, and 221. These VCPs cover the same number of elevation angles and schemes as VCPs 21, 11, and 12, respectively (just take off the leftmost number), but include special algorithms and filters designed to reduce problems with anomalous propagation or the Doppler Dilemma. The elevation angles used for each VCP are listed in the table on page 27. Listings are staggered for precipitation mode scans to show the layers that are omitted for VCPs 21, 121, and

26 A schematic for radar scanning. Radar scans in 360 horizontally at multiple elevations. Base reflectivity only shows the 0.5 scan, though. Lines represent planes through which the radar scans according to the different elevation angles. The cone of silence is denoted as the region above the highest elevation scan where the radar cannot detect anything. Drawing is not to scale. 26

29 Wind farm ground clutter. Base reflectivity from the Dodge City, KS (KDDC) radar site is shown. Ground clutter is evident as the very low reflectivity scattered about the site. A closer look at image reveals several green blotches near the site. Animation of this imagery shows those blotches are not moving, nor are they changing in intensity. These are actually wind farms being detected by the radar. The beams from the radar are bouncing off the individual turbines and towers in the wind farm, thus showing up as reflectivity in the image. Note that the radar is in clear-air mode so that the maximum reflectivity it can detect is only about 30 dbz, which is what the reflectivity from the wind farms is. If the radar were in precipitation mode, the reflectivity from the wind farms would likely be higher. Image courtesy of UCAR: 29

30 Traffic ground clutter. Base reflectivity (above) and base velocity (below) are shown from the Davenport, IA (KDVN) radar using the Gibson Ridge software. Note the ground clutter scattered throughout each image. There are particular echoes, however, near the center of the images, very near the radar site. These echoes are actually a result of radar beams bouncing off cars on interstate 80 (thin red line running across the image). Similar echoes are faint also along highway 61 running due north from the center of the image (thin orange line). The large velocity values are a result of the speed of the traffic as it travels down interstate 80. It might seem odd that, given the color, the direction of travel appears only east to west. Remember that, like reflectivity, the velocity displayed is an average of the velocities of all particles in each bin. Thus, it is likely that there are vehicles traveling both ways on all roads, but there are more traveling one way than another, thus giving the large values of velocity moving from right to left. 30

32 when the amount of water vapor (measured by the dewpoint temperature) at the surface is very high, can enhance this effect. Schematic of beam refraction. The approximate paths taken by radar beams being refracted are shown. Superrefraction and ducting. Base reflectivity from KDVN is shown using the Java NEXRAD Viewer. Ducting of the radar beams is causing the ground to reflect energy back towards the radar, giving the nearly uniform circle of reflectivity centered over the site. No precipitation is occurring within this reflectivity, but distant storms are apparent farther from the radar. Superrefraction is likely occurring with the beams traveling further to the storms, so the heights of those storms are probably being overestimated. 32

### WSR - Weather Surveillance Radar

1 of 7 Radar by Paul Sirvatka College of DuPage Meteorology WSR - Weather Surveillance Radar It was learned during World War II that electromagnetic radiation could be sent out, bounced off an object and

Weather Radar Basics RADAR: Radio Detection And Ranging Developed during World War II as a method to detect the presence of ships and aircraft (the military considered weather targets as noise) Since WW

### 1. Specific Differential Phase (KDP)

1. Specific Differential Phase (KDP) Instructor Notes: Welcome to the dual polarization radar course. I am Clark Payne with the Warning Decision Training Branch. This lesson is part of the dual-pol products

### P2.15 A Data Quality Comparison of the WSR-88D Legacy Radar Data Acquisition (RDA) to the Open RDA (ORDA), in a Challenging Clutter Regime

P2.15 A Data Quality Comparison of the WSR-88D Legacy Radar Data Acquisition (RDA) to the Open RDA (ORDA), in a Challenging Clutter Regime Charles A. Ray* RS Information Systems, Inc. Norman, OK 73072

### Bronx High School of Science Regents Physics

Bronx High School of Science Regents Physics 1. Orange light has a frequency of 5.0 10 14 hertz in a vacuum. What is the wavelength of this light? (A) 1.5 10 23 m (C) 6.0 10 7 m (B) 1.7 10 6 m (D) 2.0

### Physical Science Study Guide Unit 7 Wave properties and behaviors, electromagnetic spectrum, Doppler Effect

Objectives: PS-7.1 Physical Science Study Guide Unit 7 Wave properties and behaviors, electromagnetic spectrum, Doppler Effect Illustrate ways that the energy of waves is transferred by interaction with

### Technician Licensing Class

Technician Licensing Class Weak Signal Propagation Presented by Ryan Caron NX1U Amateur Radio Technician Class Element 2 Course Presentation ELEMENT 2 SUB-ELEMENTS (Groupings) About Ham Radio Call Signs

### Technical Attachment. The National Weather Service Estimated Actual Velocity Radar Tool. Ken Falk WFO Shreveport, Louisiana

SRH STSD 2007-03 October 2007 Technical Attachment The National Weather Service Estimated Actual Velocity Radar Tool 1. Introduction Ken Falk WFO Shreveport, Louisiana A radar analysis tool has been introduced

### Name Period 4 th Six Weeks Notes 2015 Weather

Name Period 4 th Six Weeks Notes 2015 Weather Radiation Convection Currents Winds Jet Streams Energy from the Sun reaches Earth as electromagnetic waves This energy fuels all life on Earth including the

### Overview. What is EMR? Electromagnetic Radiation (EMR) LA502 Special Studies Remote Sensing

LA502 Special Studies Remote Sensing Electromagnetic Radiation (EMR) Dr. Ragab Khalil Department of Landscape Architecture Faculty of Environmental Design King AbdulAziz University Room 103 Overview What

### STOP for science. Light is a wave. Like waves in water, it can be characterized by a wavelength.

INTRODUCTION Most students have encountered rainbows, either spotting them directly on those special days when the raindrops fall while the Sun still finds cloudless regions to peek through, or at least

### Chapter 24. Wave Optics

Chapter 24 Wave Optics Wave Optics The wave nature of light is needed to explain various phenomena. Interference Diffraction Polarization The particle nature of light was the basis for ray (geometric)

### Weather and Climate Review

Weather and Climate Review STUFF YOU NEED TO KNOW and to UNDERSTAND! 1) Because water has a higher specific heat than land, water will warm and cool more slowly than the land will. Because of this: a)

### MECHANICS PROJECTILE MOTION

1 MECHANICS PROJECTILE MOTION When an object is in free fall, the object is at an acceleration of 10m/s down Displacement is the straight line from start to finish in that direction Projectile: An object

### Precipitation forms from water droplets or ice crystals.

KEY CONCEPT Water falls to Earth s surface as precipitation. BEFORE, you learned Water moves between Earth's surface and the atmosphere Water vapor condenses into clouds NOW, you will learn How precipitation

### 4 Forecasting the Weather

CHAPTER 21 4 Forecasting the Weather SECTION Weather KEY IDEAS As you read this section, keep these questions in mind: How do weather stations communicate weather data? How do meteorologists create weather

### After a wave passes through a medium, how does the position of that medium compare to its original position?

Light Waves Test Question Bank Standard/Advanced Name: Question 1 (1 point) The electromagnetic waves with the highest frequencies are called A. radio waves. B. gamma rays. C. X-rays. D. visible light.

### Classic Anvil Shaped Thunderstorm

Classic Anvil Shaped Thunderstorm Many of the illustrations and explanations in this power point came from http://www.srh.weather.gov/jetstream/index.htm Overshooting Top Indicates Strong Updrafts Life

### Precipitation radar. Martin Hagen Institut für Physik der Atmosphäre DLR Oberpfaffenhofen Germany. Institut für Physik der Atmosphäre

Precipitation radar Martin Hagen DLR Oberpfaffenhofen Germany Weather Precipitation radar Martin Hagen DLR Oberpfaffenhofen Germany Weather Radar Weather radar systems are routinely used to sense the 3-D

### Lecture 7a: Cloud Development and Forms

Lecture 7a: Cloud Development and Forms Why Clouds Form Cloud Types (from The Blue Planet ) Why Clouds Form? Clouds form when air rises and becomes saturated in response to adiabatic cooling. Four Ways

### Geology 1347 Meteorology

Geology 1347 Meteorology Exam 1 Review 1. Carbon dioxide enters the atmosphere: a. mainly through the decay of vegetation b. volcanic eruptions c. exhalations of animal life d. burning of fossil fuels

### Air Masses and Fronts

Air Masses and Fronts Air Masses The weather of the United States east of the Rocky Mountains is dominated by large masses of air that travel south from the wide expanses of land in Canada, and north from

### physics 1/12/2016 Chapter 20 Lecture Chapter 20 Traveling Waves

Chapter 20 Lecture physics FOR SCIENTISTS AND ENGINEERS a strategic approach THIRD EDITION randall d. knight Chapter 20 Traveling Waves Chapter Goal: To learn the basic properties of traveling waves. Slide

### Convective Clouds. Convective clouds 1

Convective clouds 1 Convective Clouds Introduction Convective clouds are formed in vertical motions that result from the instability of the atmosphere. This instability can be caused by: a. heating at

### Weather Map Analysis Lab

Weather Map Analysis Lab Background: The purpose of this lab is to illustrate the construction and use of weather maps and to help you identify air masses, fronts and mid-latitude cyclones on weather maps.

### 11.2 THE DOPPLER EFFECT Notes

11.2 THE DOPPLER EFFECT Notes III. HOW THE DOPPLER EFFECT WORKS WITH SOUND A. SOUND FREQUENCY AND PITCH The frequency of sound waves is proportional to the pitch that we hear. DEMO Tuning Forks f = higher

### Physics 202 Problems - Week 8 Worked Problems Chapter 25: 7, 23, 36, 62, 72

Physics 202 Problems - Week 8 Worked Problems Chapter 25: 7, 23, 36, 62, 72 Problem 25.7) A light beam traveling in the negative z direction has a magnetic field B = (2.32 10 9 T )ˆx + ( 4.02 10 9 T )ŷ

Weather Help - NEXRAD Radar Maps Base Reflectivity Base Reflectivity Severe Thunderstorm/Torna do Watch Areas 16 levels depicted with colors from dark green (very light) to red (extreme) that indicate

### Activity 7 Precipitation Patterns Level 2

Activity 7 Precipitation Patterns Level 2 http://www.uni.edu/storm/activities/level2/index.shtml Objective: Students will demonstrate the relationship between precipitation types and surface temperatures.

### INTEGRATED SCIENCE 1: UNIT 4: PHYSICS

INTEGRATED SCIENCE 1: UNIT 4: PHYSICS Sub Unit 1: Waves TEST 2: Electromagnetic Waves Form A MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1)Electromagnetic

### Motion Graphs. It is said that a picture is worth a thousand words. The same can be said for a graph.

Motion Graphs It is said that a picture is worth a thousand words. The same can be said for a graph. Once you learn to read the graphs of the motion of objects, you can tell at a glance if the object in

### Surface Analysis Maps

Notes 1 Weather Maps The purpose of a weather map is to give a graphical or pictorial image of weather to a meteorologist. As a forecasting tool, weather maps allow a meteorologist to see what is happening

### The Application of Land Use/ Land Cover (Clutter) Data to Wireless Communication System Design

Technology White Paper The Application of Land Use/ Land Cover (Clutter) Data to Wireless Communication System Design The Power of Planning 1 Harry Anderson, Ted Hicks, Jody Kirtner EDX Wireless, LLC Eugene,

### Antenna Deployment Technical Brief

ProCurve Networking Antenna Deployment Technical Brief Introduction... 2 Antenna types... 2 Omni directional antennas... 2 Directional antennas... 2 Diversity antennas... 3 High gain directional antennas...

### In a majority of ice-crystal icing engine events, convective weather occurs in a very warm, moist, tropical-like environment. aero quarterly qtr_01 10

In a majority of ice-crystal icing engine events, convective weather occurs in a very warm, moist, tropical-like environment. 22 avoiding convective Weather linked to Ice-crystal Icing engine events understanding

### Physics 10. Lecture 29A. "There are two ways of spreading light: to be the candle or the mirror that reflects it." --Edith Wharton

Physics 10 Lecture 29A "There are two ways of spreading light: to be the candle or the mirror that reflects it." --Edith Wharton Converging Lenses What if we wanted to use refraction to converge parallel

### Waves Review Checklist Pulses 5.1.1A Explain the relationship between the period of a pendulum and the factors involved in building one

5.1.1 Oscillating Systems Waves Review Checklist 5.1.2 Pulses 5.1.1A Explain the relationship between the period of a pendulum and the factors involved in building one Four pendulums are built as shown

### SIXTH GRADE WEATHER 1 WEEK LESSON PLANS AND ACTIVITIES

SIXTH GRADE WEATHER 1 WEEK LESSON PLANS AND ACTIVITIES WATER CYCLE OVERVIEW OF SIXTH GRADE WATER WEEK 1. PRE: Evaluating components of the water cycle. LAB: Experimenting with porosity and permeability.

### STAAR Science Tutorial 30 TEK 8.8C: Electromagnetic Waves

Name: Teacher: Pd. Date: STAAR Science Tutorial 30 TEK 8.8C: Electromagnetic Waves TEK 8.8C: Explore how different wavelengths of the electromagnetic spectrum such as light and radio waves are used to

### Chapter 8 Circulation of the Atmosphere

Chapter 8 Circulation of the Atmosphere The Atmosphere Is Composed Mainly of Nitrogen, Oxygen, and Water Vapor What are some properties of the atmosphere? Solar Radiation - initial source of energy to

### Forensic meteorological investigation of hail occurrence in Clermont, FL, on 3/24/2013 and during the period 4/1/2015 7/3/2015.

Forensic meteorological investigation of hail occurrence in Clermont, FL, on 3/24/2013 and during the period 4/1/2015 7/3/2015. PREPARED ON: 6 8 November 2015 PREPARED FOR: Mr. Tom Smith, Field Claims

### And although two objects like these bumper boats cannot be in the same place on the water at the same time, water waves can. Why is that?

Physics 1103 Wave Interactions (picture of beach on screen) Today, we go back to the beach to investigate more wave interactions. For example, what makes these waves change direction as they approach the

### Digital Signal Processing For Radar Applications

Digital Signal Processing For Radar Applications Altera Corporation Radar: RAdio Detection And Ranging Need a directional radio beam Measure time between transmit pulse and receive pulse Find Distance:

### Chapter 3 Weather Maps

Chapter 3 Weather Maps Surface Station Model Used to plot surface weather observations on weather maps It shows: Temperature (deg F) Dewpoint Temperature (deg F) Coded Sea Level Pressure Wind speed and

Name Reading a Weather Map by Cindy Grigg Answer the following questions BEFORE you read this book. It is okay if you do not know as much as you thought. Do the best you can! 1. What kinds of information

### Antenna Properties and their impact on Wireless System Performance. Dr. Steven R. Best. Cushcraft Corporation 48 Perimeter Road Manchester, NH 03013

Antenna Properties and their impact on Wireless System Performance Dr. Steven R. Best Cushcraft Corporation 48 Perimeter Road Manchester, NH 03013 Phone (603) 627-7877 FAX: (603) 627-1764 Email: sbest@cushcraft.com

### Propagation Effects & their Impact

Propagation Effects & their Impact Many phenomena causes lead signal loss on through the earths atmosphere: Atmospheric Absorption (gaseous effects) Cloud Attenuation (aerosolic and ice particles Tropospheric

### Processes affecting propagation of electromagnetic radiation (light)

Chapter 4 Light and Color, and Atmospheric Optics Useful links: http://www.atoptics.co.uk/ http://www.gi.alaska.edu/atmossci/links.mainpage/arcti c_optical.html Processes affecting propagation of electromagnetic

### Water Resources Engineering Prof. R Srivastava Department of Civil Engineering Indian Institute of Technology, Kanpur. Lecture No.

1 Water Resources Engineering Prof. R Srivastava Department of Civil Engineering Indian Institute of Technology, Kanpur Lecture No. 16 In today s lecture we will look at various components of the water

### LESSON 3 PREDICTING WEATHER. Chapter 7, Weather and Climate

LESSON 3 PREDICTING WEATHER Chapter 7, Weather and Climate OBJECTIVES Describe high- and low- pressure systems and the weather associated with each. Explain how technology is used to study weather. MAIN

### 1. The map below shows high-pressure and low-pressure weather systems in the United States.

1. The map below shows high-pressure and low-pressure weather systems in the United States. 6. Which map correctly shows the wind directions of the highpressure and low-pressure systems? 1) 2) Which two

### Module 13 : Measurements on Fiber Optic Systems

Module 13 : Measurements on Fiber Optic Systems Lecture : Measurements on Fiber Optic Systems Objectives In this lecture you will learn the following Measurements on Fiber Optic Systems Attenuation (Loss)

Chapter 2: Electromagnetic Radiation Radiant Energy I Goals of Period 2 Section 2.1: To introduce electromagnetic radiation Section 2.2: To discuss the wave model of radiant energy Section 2.3: To describe

### Geomorphology G322 Introduction to Aerial Photographs

Geomorphology G322 Introduction to Aerial Photographs I. Introduction to Air Photos A. Aerial photographs are acquired by airpcraft especially equipped with cameras and view ports. 1. Early Work... Balloon-based

### WEATHER THEORY Temperature, Pressure And Moisture

WEATHER THEORY Temperature, Pressure And Moisture Air Masses And Fronts Weather Theory- Page 77 Every physical process of weather is a result of a heat exchange. The standard sea level temperature is 59

### Introduction. Antennas and Propagation. Types of Antennas. Radiation Patterns. Antenna Gain. Antenna Gain

Introduction Antennas and Propagation Chapter 5 An antenna is an electrical conductor or system of conductors Transmission - radiates electromagnetic energy into space Reception - collects electromagnetic

### FOR SUBSCRIBERS ONLY! - TRIAL PASSWORD USERS MAY NOT REPRODUCE AND DISTRIBUTE PRINTABLE MATERIALS OFF THE SOLPASS WEBSITE!

FOR SUBSCRIBERS ONLY! - TRIAL PASSWORD USERS MAY NOT REPRODUCE AND DISTRIBUTE PRINTABLE MATERIALS OFF THE SOLPASS WEBSITE! 1 NAME DATE GRADE 5 SCIENCE SOL REVIEW WEATHER LABEL the 3 stages of the water

### Antennas & Propagation. CS 6710 Spring 2010 Rajmohan Rajaraman

Antennas & Propagation CS 6710 Spring 2010 Rajmohan Rajaraman Introduction An antenna is an electrical conductor or system of conductors o Transmission - radiates electromagnetic energy into space o Reception

How to analyze synoptic-scale weather patterns Table of Contents Before You Begin... 2 1. Identify H and L pressure systems... 3 2. Locate fronts and determine frontal activity... 5 3. Determine surface

### Name Class Date STUDY GUIDE FOR CONTENT MASTERY

Atmosphere SECTION 11.1 Atmospheric Basics In your textbook, read about the composition of the atmosphere. Circle the letter of the choice that best completes the statement. 1. Most of Earth s atmosphere

### Wave Vocabulary- 25 words 1. WAVE 2. MEDIUM 3. MECHANICAL WAVE 4. ELECTROMAGNETIC WAVES 5. ENERGY 6. TRANSVERSE WAVES 7. LONGITUDINAL WAVES 8.

WAVES Chapter 11 Wave Vocabulary- 25 words 1. WAVE 2. MEDIUM 3. MECHANICAL WAVE 4. ELECTROMAGNETIC WAVES 5. ENERGY 6. TRANSVERSE WAVES 7. LONGITUDINAL WAVES 8. CREST 9. TROUGH 10. INTERFERENCE 11. CONSTRUCTIVE

### Waves - Transverse and Longitudinal Waves

Waves - Transverse and Longitudinal Waves wave may be defined as a periodic disturbance in a medium that carries energy from one point to another. ll waves require a source and a medium of propagation.

### Name: Date: Core: 20 percent is absorbed by gases and particles in the atmosphere.

Name: Date: Core: About 25 percent of incoming sunlight is reflected by clouds, dust, and gases in the air. About 50 percent is absorbed by Earth s surface. This energy heats the land and water. 20 percent

### Unit 2: Synoptic Scale (Regional) Weather & Climate

Unit 2: Synoptic Scale (Regional) Weather & Climate Synoptic scale: Length: ~1000km (~600miles) to ~6000km (~3500miles) ~Length of Alabama to the length of the U.S. Time: Hours to Days (up to 1 week) So

### Chapter 5 Perspective in Motion: Galilean Relativity and the Doppler Effect

Chapter 5 Perspective in Motion: Galilean Relativity and the Doppler Effect Much can be and has been written about the astronomer, mathematician, and physicist Galileo Galilei (1564-1642). Galileo's was

### 5. The Nature of Light. Does Light Travel Infinitely Fast? EMR Travels At Finite Speed. EMR: Electric & Magnetic Waves

5. The Nature of Light Light travels in vacuum at 3.0. 10 8 m/s Light is one form of electromagnetic radiation Continuous radiation: Based on temperature Wien s Law & the Stefan-Boltzmann Law Light has

### Periodic Wave Phenomena

Name: Periodic Wave Phenomena 1. The diagram shows radar waves being emitted from a stationary police car and reflected by a moving car back to the police car. The difference in apparent frequency between

### AP Physics B Ch. 23 and Ch. 24 Geometric Optics and Wave Nature of Light

AP Physics B Ch. 23 and Ch. 24 Geometric Optics and Wave Nature of Light Name: Period: Date: MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Reflection,

### Clouds. A simple scientific explanation for the weather-curious. By Kira R. Erickson

Clouds A simple scientific explanation for the weather-curious By Kira R. Erickson Table of Contents 1 3 4 INTRO 2 Page 3 How Clouds Are Formed Types of Clouds Clouds and Weather More Information Page

### Omni Antenna vs. Directional Antenna

Omni Antenna vs. Directional Antenna Document ID: 82068 Contents Introduction Prerequisites Requirements Components Used Conventions Basic Definitions and Antenna Concepts Indoor Effects Omni Antenna Pros

### How Can You Predict When Severe Weather Will Occur?

4.7 Explain How Can You Predict When Severe Weather Will Occur? In this Learning Set, you have been exploring how winds and oceans affect weather and climate. You then used what you know to explain how

### Weather: Air Patterns

Weather: Air Patterns Weather: Air Patterns Weather results from global patterns in the atmosphere interacting with local conditions. You have probably experienced seasonal shifts, such as winter in New

### The spatial and temporal variability of the vertical dimension of rainstorms and their relation with precipitation intensity

The spatial and temporal variability of the vertical dimension of rainstorms and their relation with precipitation intensity Kenny Aberson De Bilt, 2011 Intern rapport; IR 2011-03 The spatial and temporal

### Solar Storms and You! Exploring the Aurora and the Ionosphere, pp/ 9-14, NASA EG GSFC

Lesson Summary Students use an AM radio to monitor changes in the intensity of solar output Prior Knowledge & Skills Understanding of: The structure of the atmosphere Atomic structures including protons,

### Chapter 9: Air Masses and Fronts. Air Masses. Source Regions. Air masses Contain uniform temperature and humidity characteristics.

Chapter 9: Air Masses and Fronts Air masses Contain uniform temperature and humidity characteristics. What Characterize Air Masses? What Define Fronts? Fronts Boundaries between unlike air masses. Air

### Angle of an incident (arriving) ray or particle to a surface; measured from a line perpendicular to the surface (the normal) Angle of incidence

The maximum displacement of particles of the medium from their mean positions during the propagation of a wave Angle of an incident (arriving) ray or particle to a surface; measured from a line perpendicular

### T = 1 f. Phase. Measure of relative position in time within a single period of a signal For a periodic signal f(t), phase is fractional part t p

Data Transmission Concepts and terminology Transmission terminology Transmission from transmitter to receiver goes over some transmission medium using electromagnetic waves Guided media. Waves are guided

### 2. The map below shows high-pressure and low-pressure weather systems in the United States.

1. Which weather instrument has most improved the accuracy of weather forecasts over the past 40 years? 1) thermometer 3) weather satellite 2) sling psychrometer 4) weather balloon 6. Wind velocity is

### Section 12.2 Weather Systems

Section 12.2 Weather Systems Weather results when air masses with different pressures and temperatures move, change, and collide as a result of uneven heating of the Earth combined with the Earth s rotation.

### PREDICTING THE WEATHER

NAME DATE PARTNER(S) PREDICTING THE WEATHER How well does your local weatherman do in predicting the weather? Is he or she more accurate for the next day or for a week in the future? Why do you think that

### Weather Forecasting - Introduction

Chapter 14 - Weather Forecasting Weather Forecasting - Introduction Weather affects nearly everyone nearly every day Weather forecasts are issued: to save lives reduce property damage reduce crop damage

### Severe Weather A Reading A Z Level T Leveled Book Word Count: 1,775

Severe Weather A Reading A Z Level T Leveled Book Word Count: 1,775 LEVELED BOOK T SEVERE WEATHER Written by Bruce D. Cooper Illustrated by Cende Hill Visit www.readinga-z.com for thousands of books and

### Avaya WLAN 9100 External Antennas for use with the WAO-9122 Access Point

Avaya WLAN 9100 External Antennas for use with the WAO-9122 Access Point Overview To optimize the overall performance of a WLAN in an outdoor deployment it is important to understand how to maximize coverage

### Physics Open House. Faraday's Law and EM Waves Change in the magnetic field strength in coils generates a current. Electromagnetic Radiation

Electromagnetic Radiation (How we get most of our information about the cosmos) Examples of electromagnetic radiation: Light Infrared Ultraviolet Microwaves AM radio FM radio TV signals Cell phone signals

Chapter 20. Traveling Waves You may not realize it, but you are surrounded by waves. The waviness of a water wave is readily apparent, from the ripples on a pond to ocean waves large enough to surf. It

### NNIN Nanotechnology Education

NNIN Nanotechnology Education Lesson 1: Refraction Tank Teacher s Preparatory Guide Purpose: This lab will help students understand and measure the angle of incidence and the angle of refraction of a beam

### Paul Wolyn * NOAA/NWS Pueblo, Colorado

17.1 THE MARCH 2003 SNOWSTORM OVER SOUTHERN COLORADO Paul Wolyn * NOAA/NWS Pueblo, Colorado 1. INTRODUCTION From 16-19 March 2003 a heavy precipitation event struck most of eastern Colorado. In the southern

### Milestones Review 2 (PhySci_Kennedy_2) 2. Josie sees lightning off in the distance. A few seconds later she hears thunder. What can Josie conclude?

Name: Date: 1. The distance between a wave's crest and its trough is known as its A. low tide measurement. B. water depth. C. wave height. D. wave length. 2. Josie sees lightning off in the distance. A

### Directional or Omnidirectional Antenna?

TECHNOTE No. 1 Joe Carr's Radio Tech-Notes Directional or Omnidirectional Antenna? Joseph J. Carr Universal Radio Research 6830 Americana Parkway Reynoldsburg, Ohio 43068 1 Directional or Omnidirectional

### Storm Type. Mteor 417 Iowa State University Week 8 Bill Gallus

Storm Type Mteor 417 Iowa State University Week 8 Bill Gallus Three Major Types of Storms Single Cell Multicell Supercell Single Cell (Ordinary Cell) A) Forecasting Hints 1. Generally occur with instability

### 1. Units of a magnetic field might be: A. C m/s B. C s/m C. C/kg D. kg/c s E. N/C m ans: D

Chapter 28: MAGNETIC FIELDS 1 Units of a magnetic field might be: A C m/s B C s/m C C/kg D kg/c s E N/C m 2 In the formula F = q v B: A F must be perpendicular to v but not necessarily to B B F must be

### ABM Non-Contact Level Devices MORE AT:

ABM Non-Contact Level Devices MORE AT: WWW.ABMSENSOR.COM Propagation of Ultrasonic and Electromagnetic Waves RADAR ANTENNA REFLECTOR (Water) ULTRASONIC TRANSDUCER (Matched to AIR) Speed of Ultrasonic wave

### Overview of the IR channels and their applications

Ján Kaňák Slovak Hydrometeorological Institute Jan.kanak@shmu.sk Overview of the IR channels and their applications EUMeTrain, 14 June 2011 Ján Kaňák, SHMÚ 1 Basics in satellite Infrared image interpretation

Primus 880 Weather Radar Reliable Weather Avoidance Radar Honeywell, the world s leader in avionics continues the development of weather radar systems with the Primus 880 featuring 10 kilowatts of transmitter

### 3.14 understand that light waves are transverse waves which can be reflected, refracted and diffracted

Light and Sound 3.14 understand that light waves are transverse waves which can be reflected, refracted and diffracted 3.15 use the law of reflection (the angle of incidence equals the angle of reflection)

### Waves Review Checklist Pulses 5.1.1A Explain the relationship between the period of a pendulum and the factors involved in building one

5.1.1 Oscillating Systems Waves Review hecklist 5.1.2 Pulses 5.1.1A Explain the relationship between the period of a pendulum and the factors involved in building one Four pendulums are built as shown