introduction: Two meteorological measurement stations have been installed in the Central Arizona-Phoenix area. The first station is located at the Lost Dutchman State Park (LDP) in Goldfield, Arizona. This station used an existing tower and was instrumented with new sensors, datalogger, and power system in May 2006. The second station is located at the Desert Botanical Garden (DBG) in Phoenix, Arizona. A new tower was mounted on a concrete pad south of the DBG trails and new sensors were installed in October 2006. These stations have been used to collect meteorological measurements that are inputs to gas and particle dry deposition models. This manual is intended to document the installation, operation, and maintenance procedures for the LDP and DBG meteorological measurement stations. More detailed information can be found in the Campbell Scientific manuals for each product (http: //www.campbellsci.com).

site descriptions: The Lost Dutchman State Park (LDP) meteorological station is approximately 55 km east of downtown Phoenix, Arizona, at the base of the Superstition Mountains to the north and east, and bordered by desert and low density residential land to the south and west. The Desert Botanical Garden (DBG) meteorological station is approximately 12 km east of downtown Phoenix, within the city of Phoenix and surrounded by urban industrial, residential, and recreational land. The vegetation canopy at both sites consists of patchy coverage of desert shrubs and trees.

measurement sensors: The towers are equipped with sensors to measure wind speed, wind direction, incoming solar radiation, air temperature, relative humidity, and precipitation. A timestamp and record number saved by the datalogger for each measurement. Each variable is measured every 5 seconds and the average (or total for precipitation and total solar radiation) is saved to the datalogger every ten minutes.

maintenance: Proper maintenance of the weather station is essential to obtaining valid data. A regular program of inspection and maintenance ensures that equipment is in good operating condition. Calibration, sensor testing, and sensor repairs are done by Campbell Scientific. The maintenance and calibration schedule for the towers and sensors is as follows: tower, enclosure, wiring, and mounting hardware: check for damage during each site visit; replace sensor cables as necessary. Pyranometer: check the level and clean the sensor head at each visit (weekly is recommended by Campbell); calibrate annually. Rain gage: clean the funnel and level the gage monthly; calibrate annually. Anemometer: visually inspect the propeller and wind vane for smooth motion monthly. Temperature/RH Probe: check the filter and radiation shield for contamination monthly; clean semiannually; calibrate annually. Solar Panel: clean the glass semi-annually (or more frequently if it becomes dirty).

data collection: Data are downloaded manually at approximately 6-month intervals.