ATMOS 312RADAR METEOROLOGY

Chapter 1: COURSE OVERVIEW

Hei

ght(

km)

Range (km)

Beam

Chapter 2:

Electric and Magnetic fields

ElectromagneticPropagation

ElectromagneticSpectrum

Polarization

Beam propagation through the atmosphere

Anomalous propagation

PULSEElectric

FieldSidelobes

DuplexerKlystronAmplifier

Pulsemodulator

STALOMicrowaveOscillator

FrequencyMixer

COHOMicrowaveOscillator

Amplifier

PhaseDetector

DISPLAY

switch

Half-power beamwidth

TRANSMITTER

RECEIVER

ANTENNA

FrequencyMixer

Chapter 3: Basic components of a radar, Characteristics of a microwave pulse, how microwave pulses are generated, transmitted, and received, quantities describing radar properties.

Chapter 4: Radar displays

D ista n c e (k m )

R ef le ct iv ity fa cto r (d B Z )

S tr a t i fo r m a r e a C o n v e c t io n

B BAltitude (km)

Plan Position Indicator display

Range Height Indicator display

10 20 30 40 50 60 70Reflectivity Factor (dBZ)

65 55 45 35 25 15 5

Reflectivity Factor (dBZ)

In Chapter 4, We will discuss the appearance of echoes, for example convective and stratiform, banded and not banded, and the reason for these different types of organization

ELDORA radar -15 0 15 30 45 (dBZ)

PrecipitationStreamer

Distance (km)-10 0 10

0.0

5.0

2.5

7.5H

eigh

t(k

m)

We will also discussdisplays of derivedquantities and displaysfrom non-conventionalradars such as airborneradars

Chapters 5 and 6

2

2

20

2

3

2ln1024

K

Pr

GPcZ r

t

Radar equations:

Solitary targetsDistributed targetsWeather targets

Chapter 7: Relationship of Radar Reflectivity to other meteorological quantities

Rainfall

Drop size distribution

Liquid water content

Chapter 8: Doppler radar

0 50 100 150 200 250Maximum Unambiguous Range (km)

0

3

6

9

12

15

18

21

24

27

30

33

36

39M

axim

umU

nam

bigu

ous

Vel

ocit

y(m

/s)

= 0.86 cm

= 3.2 cm

= 5.0 cm

= 10.0 cm

Measurements of Phase and the Doppler Dilemma

Pow

er(d

ecib

els

belo

wpe

ak)

0

-20

-40-Vr,max +Vr,max0

Radial Velocity (m s-1)

Mean velocity

Spectralwidth

The Doppler Spectra and its relationship to turbulence and the drop size distribution

-51 -37 -24 -10 3 17 30 44

Wind Speed (knots)

12

24

0180 225 270 315 360

Hei

ght(

kft)

Hei

ght(

kft)

12

24

0

Wind speed (kt)0 20 40 60 80

12

24

0180 225 270 315 360

Hei

ght(

kft)

Hei

ght(

kft)

12

24

0

Wind speed (kt)0 20 40 60 80

-51 -37 -24 -10 3 17 30 44

Wind Speed (knots)

Chapter 9:

Interpretation of DopplerRadar displays

Stratiform echo

Airflow in display windowRadial velocity pattern

in display window

T

Radar

50 n miles

100 n miles

N

S

EW

Displaywindow

-51 -37 -24 -10 3 17 30 44

Wind Speed (knots)

Convective storms

Detection of rotation,Straight line winds,Microbursts

North

South

East

West

H

H

H

H

V V

V

V

VrVr

RADAR

Zenith

Horizontal ring

N NE E SE S SW W NW N

0

5

10

15

-5

-10

-15

Rad

ialv

eloc

ity

Beam direction

Minimumradial velocity

looking into wind

Maximumradial velocity

looking downwind

N NE E SE S SW W NW N

0

5

10

15

-5

-10

-15

Rad

ialv

eloc

ity

Beam direction

N NE E SE S SW W NW N

0

5

10

15

-5

-10

-15

Rad

ialv

eloc

ity

Beam direction

Radial velocity

Component of radial velocity due to vertical (V) motion of precipitation

Component of radial velocity due to horizontal (H) wind

Vr

(Vr)

A

B

C

D

Chapter 10: Measurement of vertical wind profiles using VAD and wind profilers

Radar B

0

15

30

45

60

75

90

105

40 knots

Distance

along northwest

side of box (km)

Distance along

southwest side of box

(km)

RadarA0

15

30

45

60

75

90

105

Radar ARadar B

A

B

Chapter 11: Dual Doppler retrieval of 3D Wind fields in storms

Supercells MCSs Snowstorms

Hurricanes Frontal Rainbands Lake Effect Snows

Chapter 12: Radar studies of weather systems

Chapter 13: Polarization Diversity Radars

Ground

Clutter

Birds

Insects

Supercooled

Liquid

Water

Droplets

IrregularIce

Crystals

Icecrystals

WetS

now

Dry

Snow

Graupel/R

ain

Graupel/S

mallH

ail

Rain/H

ail

Heavy

Rain

Moderate

Rain

LightR

ain

Drizzle

Cloud

Hail

Chapter 14: Advanced Topics

Single Doppler retrievalOf horizontal wind fields

Mobile radar systems

-15 0 15 30 45

0 5 10 15 20 25 Range (km)

ReflectivityFactor (dBZ)

Airborne radar systems

Satellite-based radar systems

Thermodynamic retrieval of pressure and thermal fields fromthree-dimensional Doppler-derived wind fields