National Park Service Logo
PEPC Planning, Environment & Public Comment
PEPC Home Documents by Park Policy/Links Park Planning Search Documents
Existing Hodgdon Meadows NADP Sensor and Precipitation Gauge

Hodgdon Meadow NADP Monitor Relocation and Replacement

Yosemite National Park » Hodgdon Meadow NADP Monitor Relocation and Replacement » Document List

The existing National Atmospheric Deposition Program (NADP) precipitation chemistry monitoring site in Hodgdon Meadow is scheduled for an upgrade. The deposition sensor was originally installed in this location in 1981. A completely new sensor unit will replace the existing unit and will be installed about 15 meters from the current location to move it away from encroaching willows and the riparian area. The existing sensor has minimal anchoring and will be removed. The rain gauge will remain in its current location.

At the new location, a hole 12" in diameter and 18-24" deep will be excavated and filled with cement to create an anchor for the new sensor. The new sensor will be mounted on a single pole and should not exceed 5' in total height for ease of collection. A trench approximately 6" deep, 3" wide and 25' long will be dug from the rain gauge to the southwest to run wiring to the new sensor. Excavation work will be completed using hand tools.

The desired work window to complete this upgrade is late September or early October 2020.

The National Park Service Air Resources Division co-sponsors this site with the National Trends Network within the National Atmospheric Deposition Program. The NADP is co-located with the State Hygienic Laboratory at the University of Wisconsin.

Site information: http://nadp.slh.wisc.edu/data/sites/siteDetails.aspx?net=NTN&id=CA99

National Atmospheric Deposition Program: http://nadp.slh.wisc.edu/

National Trends Network: http://nadp.slh.wisc.edu/ntn/