Quiz 3

Question 1

Lapse rate

Answer 1

Relation between elevation and temp. And it’s constant

Question 2

Is condensation exo or endothermic

Answer 2

Exothermic

Question 3

Orographic storm

Answer 3

Forced lifting caused by topography
Intensity/duration: depends

Question 4

Front

Answer 4

Transition zone between two air masses

Question 5

Cold front

Answer 5

Warm air and cold air masses in collision. Warm air less dense so forced up
Intensity:high
Duration:short
Spatial:small

Question 6

Warm front

Answer 6

Warmer air overruns colder air. Warmer less dense air forced up
Intensity: low
Duration: long
Spatial: regional

Question 7

Warm occluded front

Answer 7

Cold front catches up and overtakes a warm front. Air mass taking over warm front is not as cool as the air ahead of the warm front and rides over the colder air while lifting the warm air.
Intensity: low
Duration: long
Spatial: regional

Question 8

Conective storm

Answer 8

Caused by unstable air mass and forced lifting.
Intensity: high intensity
Duration: short
Spatial: local

Question 9

Non recording gauge

Answer 9

-Simple fence post gauge
-very limited
-person has to be there to read it

Question 10

Universal weighing gauge

Answer 10

Belfort and ottpluvio
Measure precip through weight
Attached to data base

Question 11

Tipping bucket rain gauge

Answer 11

-Can give measure of intensity
-Two calibrated cups that tip when full
-once tipped sensor is triggered and data is logged

Question 12

Recording vs Non-recordimg

Answer 12

-recording: total P over any time/intensity(mm/hr). Can be set in remote locations but cost cash
-non-recording:total P over daily or seasonal. Cheap but only for local use

Question 13

Precipitation gauge needs?

Answer 13

Info needs:
-P form: rain, snow, both?
-temporal: hourly, daily, annual?
Line of sight?
-Vandalism
Instalation:
-single gauge vs network
-cost
-extraneous data

Question 14

Errors in P measurement

Answer 14

-Evaporation(-1%)
-adhesion(-.5%)
-inclination(.5%)
-splash(+/-1%)
-BIGGEST source is wind (5-80%)
-greater wind speed=less effective catch area
-

Question 15

Where to put rain gauge

Answer 15

-Forest clearings where trees are not close enough to intercept
-30-45 degree angle from top of gauge to top of obstruction
-2h from top of obstruction away

Question 16

Gauge height effect

Answer 16

As gauge is raised up wind speed increases and precipitation catch decreases

Question 17

Shield options

Answer 17

-nipher shield: splits air
-alter shield: splits air
-double fence intercomparison reference(DFIR): two fence system with an alter shield

Question 18

Hyetograph

Answer 18

Shows rainfall overtime. Be sure to use appropriate units

Question 19

Frequency, probability, and return period

Answer 19

Probability= likelihood of event happened
-m/(n+1)
-m=rank in descending order
Return period= average time separating events
-Tr=1/p
Return period and probability are inversely related

Question 20

A precipitation event of 86.4mm day is ranked number 1 in an annual maximum series of P events across 39 years. Calculate probability, probability or nine occurrence, and probability of occurrence at least once in 25 yrs

Answer 20

Probability:
-P=M/(n+1), 1÷39+1= .025
Probability of non occurrence
-P(non occurence)= 1-Poccurence
-1-.025=.975
Probability of non occurrence any year
-p(n)= 1-[Pnonoccurence]^n
- 1-[.975]^25= .4689

Question 21

Probability assumptions

Answer 21

-PROBABILITY IS NOT PREDICTIVE
-longer record=greater confidence
-assume that past events are good indication of future
-return period=avg time separating events of similar magnitude

Question 22

Partial duration series

Answer 22

Threshold value typically smallest annual max series value