My research focuses on helping to develop a better understanding of how high-elevation, low-latitude ice cores record climate. To do this, comprehensive meteorological measurements are made at ice-core sites with automated weather stations (AWS), and combined with measurements and sampling of snow and ice. These meteorological measurements are being made far above – sometimes thousands of meters above – standard weather station networks, so are helping to characterize high-elevation climate in East Africa and the Andes. Read on to learn more, or jump down to Kilimanjaro, Quelccaya Ice Cap, or Glacier Birds!

At low latitudes (i.e., tropics and subtropics), devoid of pronounced air-temperature seasonality, glaciers only exist at high elevations where sufficient snow accumulates to persist through the annual cycle – or does so in most years – or did so in the past. Snow accumulation is typically highly seasonal, with considerable interannual variability in amount and timing. AWS measurements therefore continuously record the amount and timing of snowfall events, along with other information such as where the precipitating airflow is from (wind direction), and what the air temperature was at the time. Equally important are meteorological conditions after snow deposition, between snow accumulation events. All together, these measurements permit developing a record of mass and energy exchanges, between the atmosphere and snowpack (the developing ice-core record). Over sufficient time, AWS measurements represent – or approximate – the site’s contemporary climate.

The complexity of natural systems renders all scientific research inherently difficult, and there are two inherent complications of this research. First, we work in an environment which is hostile to human existence. For example, at an elevation halfway through the atmosphere – where typical sites are located – the partial pressure of oxygen is only half that of sea level; normal physical and mental activity both require more oxygen than is available! Second, measurements must be made over a sufficiently-long period of time to represent, or at least approximate, variability of the climate system. Although longer records are always better, longterm measurement programs in extreme environments are rare, due affordability and practicality issues. In addition, deciding when enough data have been collected is difficult, as this differs for each site.

Here are specifics about my current research, with links to learn more.

Kilimanjaro

Since February 2000, we have been studying glaciers and climate at the summit of Kibo – Kilimanjaro’s highest peak. Specifically, we operate automated weather stations (AWS) on the Northern Icefield and make periodic visits to document and investigate environmental changes underway, using measurements at a network of stakes on the glaciers, GPS, and photography.

The original website for this work is here, providing an overview of the project and initial findings. Since we started, 218 days have been spent on the mountain, including 96 in the summit crater; 49 collaborators and journalists have been involved.

For up-to-date posts about Kilimanjaro research, please visit the Kiboice blog. The emphasis of this work is turning to analysis of data from the AWS, and publication of a comprehensive climatology for the Northern Icefield.

This project has been supported in part by the National Science Foundation (Grants No. 0402557 & 0952829), NOAA (OGP Climate Change Data and Detection Program & U.S. Global Climate Observing System), and the National Geographic Society. We sincerely thank the Tanzanian governmental agencies who make this research possible: COSTECH, Immigration, TAWIRI, TANAPA, and KINAPA. On the mountain we work with Summit Expeditions and Nomadic Experience (SENE) for logistical support and safety.

Quelccaya Ice Cap

We began climate research at the summit of Quelccaya Ice Cap in July 2003. This is the largest glacier in the Tropics, located at high elevation in the Cordillera Vilcanota of Peru. The primary objective of this work is to establish the summit climate, through comprehensive, continuous measurements at an automated weather station (AWS). An additional component of many visits to the site, has been to dig snowpits near the AWS and measured profiles of density, temperature, and stratigraphy through the prior year’s accumulation. In some years we have also collected a profile of frozen samples, on which isotopes and chemistry have been measured (e.g., see Hurley et al. 2019, and others here).

In 2007, collaboration began with NOAA’s Global Climate Observing System (GCOS) program, to obtain the first high-accuracy air temperature measurements at a high-elevation site (5,680 m or 18,630 feet). These data and that from the other instruments are currently being analyzed.

For a reverse chronology of posts about Quelccaya, please visit the project’s blog. In August 2018 the AWS was removed, so the research emphasis has turned to analysis of the 15-year record, and additional publications. We continue monitoring the glacier by satellite imagery, as well as several research collaborations.

Support for Quelccaya research has derived from the National Science Foundation (Grants No. 0402557 & 0952829), NOAA (OGP Climate Change Data and Detection Program & U.S. Global Climate Observing System; Grants NA09OAR4600215 and NA10OAR4310228). Thanks to Felix Benjamín Vicencio and Vicencio Expeditions, who provide fantastic field support, and to Mike Rawlins in the UMass Climate System Research Center, who until recently kept tab on telemetry.

Birds on Glaciers

Meltwater runoff from Quelccaya Ice Cap sustains vast wetlands (bofedales) between the different-age moraines. These bofedals support a tremendous diversity of life, despite their location extending up to 5,000 m elevation. During days of acclimatization at Quelccaya we have observed and photographed many of the bird species which spend time near the glacier.

Our most exciting discovery was determining that one bird species builds nests, incubates eggs, and then raises young – all on the glacier itself. This is the only bird species known to do so, anywhere in the world. Informally known as the Glacier Bird of the Andes, the species formerly classified as Diuca speculifera is now Idiopsar speculifera – the White-winged Diuca Finch. In addition, the glacier bird is one of the world’s highest-nesting passerine birds. Since this initial discovery we have documented other bird species at Quelccaya which rely upon glaciers for breeding and/or protection.

Additional information on the Glacier Bird can be found here. Our second publication (2018) provides new details and discusses other bird species using glaciers; it is available here and listed with others here. In the supplementary material accompanying the 2018 paper, there are quite a few images of nests and the glacier, along with details on viewing a BBC film about the Glacier Bird and our research (here). Our most-recent publication presents observations on high-elevation insects eaten by these bird species.

Partial fieldwork support for investigations of birds at Quelccaya by collaborator S.P. Hardy was provided by the Explorers Club (Youth Activity Fund) and a Hall/Mayfield Research Award from the Wilson Ornithological Society. We also acknowledge the BBC Natural History Unit for their collaboration (see also here). Thanks to Felix Benjamín Vicencio and Koky Castañeda of Vicencio Expeditions, who provide excellent logistical support and observational skills!