Instruments

• horizontal: 1-100 meters
• vertical: up to 100 meters
• time: hours

ex. field, building

• horizontal: 100 meters to 10 km
• vertical: up to 1 km
• time: 1 day

ex. campus, forest, city/town

• horizontal: 10 km to 100 km
• vertical: up to 6 km
• time: 1-2 days

ex. region, entire state

• horizontal: 100km to 1000km
• vertical: > 6km
• time: 1-5+ days

general circulation models

What variables do you need to measure?

What time period?

what is the required accuracy and precision?

amount of correctness

exactness

Sensing device, transducer, and transmission/readout device

1. level ground, 10m X 7m, short irigated grass (or surface representative of general area). surrounded by fense.

2. No steeply sloping ground nearby (no hollow)

3. Away from trees, cars, buildings, parking lots, .etc (most important for precip. and wind)

4. All instruments should be on same site.

5. Area with little development

6. If changes in instrumentation or site (keep old instruments/site running for one year)

7. Inspect site/instruments once every 2 years

data about data (station history, calibration, schedules, maintenance schedule, changes in location)

reference measurement - intended to define a quantity

establishes a relationship with measurement standard

difference of measurement

change in response/change in stimulus

Ability to maintain accuracy over time

Slow variation in accuracy over time

Time interval between the instant of change in stimulus and the instant when the instrument responds to the change and becomes steady.

The mean of long term measurements

follows distinct pattern

• no apparent bias
• in any direction/magnitude

spread of the data about the mean

negatively changed

positively charged

neutrally charged

product of the movement of electrons

amount of electrical "pressure" available from source

measure of the amount of current

current in one direction

current varies with time

limits or controls the flow of electricity measured in ohms

I=V/R

set of cmds that is entered into memory of DL

ability to work on matter

energy transfer from one object to another

physical contact

mass movement of fluid

EM waves

measure from ridge to ridge

measure of the trough

E = σ * T^4

• The higher the temp the shorter the λ of max radiant emission
• λ = α / T

0.2-2.0 μm

4.0 to 25.0 μm

amount of energy passing through a area per unit time

radiation flux through an area perpendicular to the top of the atmosphere

ex. clouds

ex. Rayleigh (blue) and Mae (white)

SWR not reflected or scattered

SWR is reflected or scattered

Qdir+Qdif

measures Tdiff on a surface receiving radiation

measures Qdif, Qdir, and Qt

several hundred thermocouples

an object that is a good emitter at a particular wavelength is also a good absorber at that same wavelength.

object that absorbs and emits all radiation

sensor that uses variation of physical properties of some substance according to thermal state

1.5 meters

• mechanical
• electronic
• passive/remote sensing

during the daytime and summer energy moves away from the surface downward Qg+

night and winter energy moves toward the surface (upward) Qg-

amount of heat energy input / temp. change

heat required to raise 1m^3 of substance 1 k

ability of soil to diffuse heat