Mt. McKinley Weather Station

Future Plans
It is our plan to continue the operation of the meteorological station for as long as the National Park Service and the National Weather Service need these data. The station will be serviced by the JAC every year.

2007
(Jump to the expedition blog to view the expedition notes. )

This year the expedition consisted of three climbers from Fairbanks, and eight climbers from Japan. Thanks to the Denali National Park Rangers, some of the equipment was flown up in advance of the climb. The group met in Talkeetna on June 13 and reached the weather station on June 29.  When they reached the location, they found that the weather station was completely destroyed by the natural causes during the winter.  The leg of the tetra-pod mount was bent and guide wires were torn.  Cables were broken and sensors were missing.  Although the anemometers could not be placed at the site, the temperature sensors and atmospheric pressure sensors were secured to the rocks and they continue to transmit data.

2006
(Jump to the expedition blog to view the expedition notes. )

For the first time, the weather station was put together with combined efforts between a Japanese company (Climatec) and Polartronix of Fairbanks Alaska. Technicians at Climatec were involved in putting together the weather station in the 90s when the project began and Polartronix was involved in developing the radio telemetry system when IARC took over the project.  Two climbers from IARC and six volunteers climbers from Japan went up the mountain to install the newly constructed weather station. The weather station consisted of a Vaisala 425 ultrasonic anemometer and a cup anemometer with temperature sensors and pressure sensors that connected to a Campbell data logger.  Although the anemometer was giving erratic readings, which seemed to be lower than expected, transmission from the mountain continued until February. During the successful transmission, a sharp increase in temperature was observed when the Jet Stream brought up warm air to the arctic, an event called “Chinnok”.

Weather station at installation 2006 (left) and upon return in 2007 (right)

2005
(See 2005 Expedition Notes)

 The 2005 expedition took place in June. Two sets of ultrasonic anemometers were placed on the mountain. The McKinley Weather Station has been transmitting data to the area of Cantwell receiving station, but the receiver could not pick up the signal.  Additionally, we were unable to receive the signal through Nenana to Fairbanks. The additional noise that was preventing the signal to reach the receiving station was perhaps due to increased cellular towers causing interference.  The antenna at the Cantwell receiving station was upgraded to receive the signal.  In October, the CPU was affected by cold temperature and the transmission failed soon after.

Weather station at installation 2005 (left) and upon return in 2006 (right)

2004
(See 2004 Expedition Notes)

Because of the difficulties encountered with maintaining the reliable operation of the previous weather stations, a new approach to the electronics was taken. This new approach was to use multiple redundant systems, similar to instruments used in spaceflight. For example, incorporating two wind speed sensors, an ultrasonic unit, and a traditional anemometer. The ultrasonic sensor is more immune to icing, but requires more electricity.  The cup anemometer is proven to work unless the cups brake. Both anemometer have a maximum rating of 65m/s.  In addition, two CPUs and two data transmission systems were installed, with independent power supplies. The data transmission scheme involves sending data via satellite once every 4 hours; the other scheme uses a terrestrial radio link to send data every 30 minutes.
Upon return from the expedition, the team discovered that the satellite transmission was not working as planned. Data were being received via radio telemetry, however, for unknown reasons, this degraded as well during the month of October. During this time temperature readings also became increasingly erratic. Eventually, transmission from the station has ceased.

Weather station at installation 2004

2003
 During 2003, the weather station was upgraded to address the issues of the last year’s weather station and to provide more frequent data transmission. Specifically, the upgrades included the  following:

1. Enhancements of the wind sensor to allow operation in higher winds. (Vaisala 425)
2. Data transmit delay reduced from 4 hours to 1 hour.
3. Addition of a relative humidity sensor.
4. Addition of a barometric pressure sensor.

In June of 2003, the climbing party reached the weather station and performed the necessary upgrades. Unfortunately, the electronics failed shortly after installation and no useful data  were returned. The exact cause of the electronics failure remains unknown, but a possibility is that the CPU failed because of the colder temperature. The Denali Park Rangers assisted the project by flying the instruments to Medical Camp.

Weather station at installation 2003 (left) and upon return in 2004 (right)

2002

In June of 2002, a weather station was placed on Mt. McKinley at the 18,700 foot level. This weather station was designed to transmit data in real-time for use by the climbing public and the science community. The weather station measured temperature, wind speed, and wind direction. Because of the extreme winds and icing conditions, rotating wind sensors are often destroyed within one year, so a ultrasonic anemometer (no moving parts) was used. The station began transmitting data on June 18, 2002. After installation, it was noted that wind readings were sometimes erratic during stormy conditions. Two factors are believed to cause these erratic readings. First, the ultrasonic sensor is more affected by turbulence than traditional sensors. Secondly, the winds on the mountain were often significantly higher than the wind sensor was designed to handle. The station continued to transmit data until January 7, 2003. At that time, the weather was quite stormy. We believe the weather station stopped transmitting due to the broken antenna (see photo).

Weather station at installation 2002 (left) and broken antenna (right)

How it started

The Japan Alpine Club (JAC) installed a meteorological station on a ridge near the summit of Mt. McKinley at an altitude of 18,700ft in 1990, in order to examine what could have caused the disappearance of three experienced Japanese climbers in 1989. Yoshitomi Okura could not suggest any cause other than the extremely high winds that can suddenly occur around the site where the station was installed. The National Park Service allowed the operation of the site for ten years. In 1999, JAC donated the station to IARC, hoping that the operation could be extended and improved. The National Park Service has allowed its continued operation, with the proviso that the data are made available on a real-time basis to the Park Service, the National Weather Service, and other interested parties.