Site Meteorological Measurements

HI-15 MET STATION (H15MET)

Site description: Old-growth opening/Road junction

Latitude: 44-15-51 Longitude: 122-10-26 Elevation (MSL): 922 meters

Aspect: 240 degrees Slope: 15 degrees

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AIR TEMPERATURE (H15MET)

Measurement period:: 19920312 - Present

Comments:

Daily Variables:
12 Mar 1992 to Present:
Mean, max, min daily air temperature
Time of max, time of min

Fine Resolution Variables:
12 Mar 1992 to Present:
Mean hourly air temperature

Sensor height: 480 cm (original height of both sensors)
150, 450 cm (two distinct heights established 931130)

Notes: Two temperature probes are collecting data.
CR10, samples every 10 seconds.

PROBE 01:

PROBE 02:

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DEW POINT TEMPERATURE (H15MET)

Measurement period:: 19930210 - Present

Comments:

Daily Variables:
10 Feb 1993 to Present:
Mean, min, max, daily dewpoint temperature
Time of max, time of min

Fine Resolution Variables:
10 Feb 1993 to Present:
Mean hourly dewpoint temperature

Sensor height: 480 cm (original height of both sets of temp/rh sensors)
150, 450 cm (two distinct heights established 30 Nov 1993)

Notes: Two dewpoint values are calculated from two separate
pairs of air temperature and relative humidity probes.
CR10, samples every 10 seconds.

PROBE 01:

PROBE 02:

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PRECIPITATION (H15MET)

Measurement period:: 19631001 - Present

Comments:

Daily Variables:
01 Oct 1964 to Present : Daily precipitation
18 Sep1964 to Present : Standard raingage (3 week to monthly checks)

Fine Resolution Variables:
01 Oct 1984 to 05 Aug 1992: 15 minute precipitation (adjusted to standard)
05 Aug 1992 to Present : 5 minute precipitation (not adjusted)

Gage height: 410 cm

Status: A standard rain gage has always been maintained along with
an accompanying recording rain gage. Until Aug 1992, all records
were adjusted to totals recorded from the standard rain gage. Since
Aug 1992, both the adjusted (PPTH1501) and unadjusted (PPTH1502)
recording gage records are being maintained.

The daily record for the standard rain gage record is probe 1 and has been
determined using prorating techniques with the listed recording gages.

Probe 1 (record is adjusted to the nearby standard gage):
Q-12 Recording Gage (chart) established 01 Oct 1964.
Heated Tipping Bucket (chart) replaces Q-12 on 01 Oct 1974.
A-35 Recording Gage (chart) replaces Tipping Bucket on 01 Apr 1984.
Pressure transducer with CR10 data logger replaces A-35 on 5 Aug 1992 to present.

Probe 2 (electronic high resolution record is not adjusted):
Pressure transducer with CR-10 (electronic) replaces A-35
on 30 Sep 1992, but A-35 is still maintained as a backup.

Notes: Historically, the charts were hand digitized on a daily
basis, and the daily record adjusted to the standard gage total
(prorating technique). Beginning 01 Oct 1984, all charts were
electronically digitized, and the daily record was adjusted to
the standard gage total (prorating technique). Beginning 01 Oct 1992,
electronic digitizing of charts is stopped, except to fill gaps
in the CR-10 record. The daily standard gage record is created
by prorating the total using the CR-10 record. When recording
gage malfunctions occurred, CS2MET was used to prorate the
standard gage total to obtain a daily record.

01 Oct 1964 to 01 Oct 1974
Data was collected monthly (approx.) from the standard gage
(total precip) and the adjacent Q-12 recording gage (chart).
The standard gage had a 7.75" orifice diameter.
On 10 Oct 1973, gage was replaced with an 8" diameter standard gage.
Recording gage sits atop a steel tower.

01 Oct 1974 to 01 Apr 1984
Data was collected every 3 weeks (approx.) from the standard gage
(total precip) and the adjacent Tipping Bucket recording gage
(chart). Tipping Bucket Gage replaced with a Heated recording
gage (A-35 water level recorder) on 01 Apr 1984. The gage was
troublesome in the months before replacement.

01 Apr 1984 to 30 Sep 1992
Data was collected every 3 weeks (approx.) from the standard gage
(total precip) and the adjacent A-35 recording gage (chart).
Historically, the charts were hand digitized on a daily basis and
adjusted to the standard gage total. Subsequently, the charts
were electronically digitized, and the high resolution data was
adjusted to the standard rain gage.
In March, 1984, an enclosure is built below the tower to house instruments.
In July, 1986, a new shelter is built to house the rain gage and replaces
the tower.

30 Sep 1992 to Present
Data is collected every 3 weeks (approx.) from the standard gage,
and the total is prorated using the adjacent CR-10 recorder on a
daily basis. The A-35 recording chart acts as a backup.
High resolution data collected from the CR10 is also maintained
and not adjusted to the standard rain gage.
CR10 with pressure transducer, samples every 10 seconds.


PROBE 01:

PROBE 02:

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RELATIVE HUMIDITY (H15MET)

Measurement period:: 19920312 - Present

Comments:

Daily Variables:
12 Mar 1992 to Present:
Mean, max, min daily relative humidity
Time of max, time of min

Fine Resolution Variables:
12 Mar 1992 to Present:
Hourly relative humidity

Sensor height: 480 cm (original height of both sensors)
150, 450 cm (two distinct heights established 30 Nov 1993)

Notes: Two relative humidity sensors are collecting data.
CR10 samples every 10 seconds.

PROBE 01:

PROBE 02:

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SNOW LYSIMETER (H15MET)

Measurement period:: 19901001 - Present

Comments:

Daily Variables:
01 Oct 1990 to Present :
Daily snow lysimeter runoff

Fine Resolution Variables:
01 Oct 1990 to 12 Mar 1992:
15 minute snow lysimeter runoff

12 Mar 1992 to Present :
5 minute snow lysimeter runoff

Notes: Tipping bucket tips were recorded as events on an A-35 chart
until 12 Mar 1992. The events were digitized from the chart during this period.
An event counter totaled the number of tips over the collection
period as a check. After 12 Mar 1992, tipping bucket tips are
summarized by 5 minute intervals on a CR10 recorder.
CR10, Samples every 10 seconds

PROBE 01:

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WATER VAPOR PRESSURE DEFICIT (H15MET)

Measurement period:: 19951003 - Present

Comments:

Daily Variables:
03 Oct 1995 to Present:
Mean, min, max, daily vapor pressure deficit
Time of max, time of min

Fine Resolution Variables:
03 Oct 1995 to Present:
Mean hourly vapor pressure deficit

Sensor height: 150, 450 cm

Notes: Vapor pessure deficit values are calculated from air temperature
and relative humidity probes every 15 seconds (in millibars).

PROBE 01:

PROBE 02:

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WIND SPEED AND DIRECTION (H15MET)

Measurement period:: 19920312 - Present

Comments:

Daily Variables:
12 Mar 1992 to Present:
Mean and max wind speed, resultant mean wind vector magnitude
Time of max wind speed

12 Mar 1992 to 11 Aug 1994
Resultant mean daily wind vector direction, standard deviation

11 Aug 1994 to Present
Resultant mean daily wind vector direction, standard deviation
Daily wind direction vector components (Wind Rose).

Fine Resolution Variables:
12 Mar 1992 to Present:
Hourly mean wind speed, resultant mean wind vector magnitude
Resultant mean daily wind vector direction, standard deviation,

Sensor height: 500 cm

Notes: CR10 samples every 10 seconds. Standard deviation variable
not initiated until 10 Feb 1993.

PROBE 01: