Level 1 Meteorology for all LTER Sites
The following methods are extracted from the web-page http://intranet.lternet.edu/committees/climate/climstan/obstands.htmlLevel 1 Meteorology involves continuous recording by a mechanical recorder. Sometimes, an LTER site will begin its direct meteorological reporting at Level 1. Level 1 is still regarded as interim, however; all sites should eventually maintain a Level 2 meteorological station (next main section).
Instrumentation
The instruments required for a Level 1 station (Table 5) contain some which record continuously. Other instruments are identical to those used for level 0 Table 2.
Table 5. Level 1 Meteorological Station Equipment
| Equipment | Specifications |
| Maximum and Minimum Thermometers | National Weather Service type maximum and minimum thermometers mounted on a support in the shelter for the mercury maximum thermometer and the spirit minimum thermometer. |
| Shelter | Cotton Region type, medium size (20x30x32 inch box). |
| Precipitation Gage | Capacity of measuring tube is 2 inches
(~50 mm) of
rainfall with overflow capacity of 7 inches (~180 mm). Funnel to measuring tube area ratio is 10:1 so that 1 mm of rain produces a 10 mm depth for measurement to the nearest 0.10 cm. Where data are taken from NWS Coop stations measurement may be to the nearest 0.25cm. |
| Thermograph | Air temperature measured with bimetallic strip. Continuous record on a seven day drum rotation. |
| Recording Precipitation Gage | NADP Station, weighing pan or tipping Gage bucket gage |
Installation of the instrument shelter, air thermometers and preciptation gage should follow the NWS guidelines for Cooperative Observer Stations (USDC, 1989). When NWS standards for electronic temperature measurements at cooperative observer stations are established, these will also be acceptable guidelines for LTER sites. The level 1 site has much the same instrumentation as the level 0 site (Table 2).
Measurements
Maximum and mininum temperatures for the calendar day are extracted from a strip chart. Total precipitation is computed from a continous chart and checked against the totalizing precipitation gage.
Preprocessing
Relatively little preprocessing at the site is required for Level 1 (and Level 0) data.
Temperature
- Maximum: Directly measured, reported in degrees Celsius
- Minimum: Directly measured, reported in degrees Celsius
- Mean: computed as average of Maximum and Minimum
Precipitation
- Liquid: Directly measured, reported as mm of water
- Frozen: computed as water equivalent (USDC, 1989), reported as mm of water.