Warming at Every Elevation in Great Basin National Park

Written from an article by Bryan Mark and James DeGrand (Ohio State University), David Porinchu (University of Georgia) and Scott Reinemann (Sinclair Community College).

The planet's average temperature is rising, and studies in other mountain ranges suggest that higher elevations may be warming faster than lower ones. Great Basin National Park is a hard place to test that: its temperatures vary widely across terrain that runs from the desert floor to the mountain summits, through very different biomes. The authors summarize a study they published in 2020, from a long collaboration between universities and park staff.

Sensors in the trees

To follow temperature across the whole park, the team set up an embedded sensor network (ESN) — sensors placed in different spots, mostly in trees.

• Started: 2006. By 2020 it had 29 sensors.
• Range: 2,300 m (7,800 feet) of elevation — from near the summits of Wheeler, Bald and Buck mountains, along ridgelines and streams in neighboring east-draining watersheds, down to the Great Basin Visitor Center.
• Zones: tundra, sub-alpine forest and lakes, sagebrush meadows, and a rock glacier.
• Readings: hourly air temperature and humidity near the ground — shaded from direct sun, at about a person's height.

Three of the dataloggers, in radiation shields:

Students and staff from Ohio State University and the University of Georgia have kept the network running for over 12 years, with park staff, on annual educational research expeditions called GBEx (Great Basin Expedition).

Checking the record

The study covered 12 years, 2006–2018. After quality control of every hourly reading, the team checked its results against:

• the Mather Overlook RAWS weather station;
• the Wheeler Peak SNOTEL station;
• PRISM, a gridded climate dataset that interpolates temperatures across the landscape.

The comparisons were very consistent.

What they found

• Warming everywhere: daily maximum, minimum and mean temperatures rose significantly at all elevations.
• Warmer nights: the average daily minimum rose by 2.1°C (3.8°F).
• Fastest at the top: above 3500 m, daily maximum temperatures rose significantly faster than lower down — a sign that daytime factors may be driving extra warming at the park's highest elevations.

Why a network

A few existing weather stations, such as the Wheeler Peak SNOTEL site, cannot capture how much temperature varies from place to place in the park. A network like this is a low-cost way to keep long-term, spread-out records at finer detail in varied mountain terrain.

In arid mountains, where water supplies are vulnerable and ecosystems fragile, the authors conclude that such networks must be kept up and extended as climate change continues to alter conditions.

Sources

Based on "Temperature Changes across an Elevational Gradient," by Bryan Mark, James DeGrand, David Porinchu and Scott Reinemann, The Midden — Great Basin National Park, Vol. 20, No. 2, Winter 2020, published by the National Park Service and in the public domain; rewritten in hubnx's own words. The study's diagram of the sensor sites and the expedition's photographs of its team, both the universities' work, are not reproduced.