Cog Railway Mesonet Overview

By Keith Garrett | November 12, 2024

Skyline mesonet station installation on September 3, 2024.

The Cog Railway Vertical Profile is nearly online. Currently, three new stations have been brought online. The first is at 2,620 feet, in an open grassy area next to the pond at Marshfield Station at the base of the Cog Railway. The next is at 3,430 feet along the tracks, close to an area called Cold Springs. Continuing uphill, the third station will be installed at 3,850 feet attached to an on top of Waumbek Station. Half Way house is next, coming in at 4,465 feet, which is being completely replaced with all new instrumentation. Finally, the last station before you reach the summit is Skyline, located at 5,556 feet and is also fully operational.  These new stations will allow for research to compare weather on both the east side (The Mount Washington Auto Road) and this new vertical profile on the West side of Mount Washington.

This project is the first part of our Northern Borders Regional Commission grant to expand our mesonet from the White Mountains northward to the Canadian border.

The stations at Marshfield, Cold Springs, and Skyline are already online, and recording wind speed and direction, two temperature probes, relative humidity, station pressure, solar radiation, and soil moisture and electrical conductivity. Each station is solar powered, and communicates via microwave radio to an access point between 7 and 9 miles away.

Many remote automated weather stations use solar and battery storage to power their sensors, datalogger, and data transmission systems. The average station uses a 50 watt solar panel with a 100 amp hour battery.  These stations use a single 90 watt panel, and have 500 amp hours of 12 volt AGM battery capacity. Currently, we can’t charge lithium iron phosphate(Lifep04) efficiently with the weather on Mount Washington, but we are running a few tests with some 100 amp hour Lifep04 batteries with different internal heater configurations. Off the shelf 12v heated batteries require about 10 amps coming from the solar array to turn on, which would require two panels operating near peak efficiency- nothing like attaching a large sail to a device located in one of the windiest locations on the planet!

A week was spent optimizing power consumption of a completed station, with a goal of a station being able to operate for up to 30 days without sunlight.  As many of you are aware, winters are dark, and each station is expected to be covered with snow and ice for long periods. When these stations are just taking measurements, their idle draw is 1 watt.  Every 20 minutes, the radios are powered on and data is sent to our systems, during which the power draw increases to about 7.5 watts. This window can be shortened, but it takes 1 minute 22 seconds for the radio to boot, and our systems for these new stations poll 1 time per minute, leaving close to two minutes of wasted power-on time. A future revision of our management code will address this, letting the station power on the radio and quickly push out stored measurements, then immediately power off the radio. There are less power-hungry communication options available, but for the future equipment we expect to be added to these locations, these microwave radios were preferred over bandwidth limited cellular and serial communications.

Metadata, metadata, metadata! Metadata is additional information stored along with measurements.  These include but are not limited to GPS coordinates, elevation, installation information such as height above ground for a sensor, instrument serial numbers, sensor calibration information, land use, vegetation type- the list goes on.  Our metadata storage and dissemination system as been brought up to current standards, and we are now using an in-house developed software package that tracks changes across our network of automated stations, as well as summit instrumentation.  Instruments are added, their history is tracked as they move from location to location either while being repaired, or calibrated. Station work history is logged, potential errors in data are flagged, and a comprehensive site history is kept for each location. This type of metadata is required for quality control of research grade data.  This new system generates all necessary or requested information dynamically for dissemination in JSON, XML, and KML formats, which any data scientist can assimilate for their needs.

Screenshot of mesonet manager.

Installation at Halfway House, October 24, 2024.