2015 - Cosmic-ray hydrometrology: Measuring water at the land surface using cosmic-ray neutrons




May 11-13, 2015

Department of Geosciences and Natural Resource Management
University of Copenhagen, Denmark
Øster Voldgade 10 - Copenhagen
Meeting room 1 - 3rd floor - Area 6

Professor Marek Zreda, University of Arizona, USA



Cosmic-ray method
Cosmic-ray neutrons can be used to measure water at and near the land surface, mainly soil water, snow and water in and on vegetation. The cosmic-ray method takes advantage of the inverse relation between the intensity of cosmogenic neutrons in air above land surface and soil moisture. With a unique horizontal footprint of hectometers and a vertical footprint of decimeters, cosmic-ray measurements average out small-scale variations in soil moisture and provide an area-average, representative measure of soil moisture. The cosmic-ray method has been adopted widely and many new applications are being developed. Examples include measuring snow water equivalent and vegetation water equivalent, determining infiltration rates and unsaturated hydraulic conductivity of soils, mapping soil moisture over large areas using mobile cosmic-ray probes, measuring rainfall rates, and measuring the amount of snow and liquid water on canopy.

Course scope
In the course we will discuss the principles and applications of the cosmic-ray method for measuring water at the land surface. The course will consist of lectures, individual work assignments (reading papers and conducting computations), and discussion sessions. The students will learn about all aspects of the cosmic-ray method, including the basic cosmic-ray physics (why the method works), data collection (the instrument and infrastructure), calibration, and data processing and interpretation (how the method works). We will also discuss how the cosmic-ray data can be used together with other data to provide better products, and how the cosmic-ray measurements can be used within hydrological framework for example to understand mass balance.

Course outline
Day 1, morning: surface moisture
Introduction to and overview of the course
Importance of surface moisture
Soil moisture in hydrologic cycle
Spatial heterogeneity of soil moisture
Methods for measuring soil moisture at different scales
Other reservoirs of water at the land surface
Summary, questions and discussions.

Day 1, afternoon: cosmic rays on Earth
Elements of nuclear physics
Basic definitions
Principles of cosmic-ray physics
Spatio-temporal variations of cosmic-ray neutrons
- basic/useful computations/algorithms;
- acquiring and manipulating data sets;
Summary, questions and discussions.
Work assignments.

Day 1, evening
Work assignments (reading, computations, analysis)

Day 2, morning: measuring soil moisture with cosmic-ray neutrons
[Optional: reports from assigned work]
Cosmic-ray method for measuring surface moisture
Response function
Ancillary data needed
Computations (including corrections)
Support volume (2D footprint, soil thickness, volume of air)
Summary, questions and discussions.

Day 2, afternoon: measuring other water at the land surface
Snow water equivalent
Water in vegetation
Intercepted water (rain, snow)
- full computation - from neutron intensity to soil moisture;
- computing effects of individual variables (e.g., pressure, humidity);
- computing effects of lattice water and organic matter;
Summary, questions and discussions.
Work assignments.

Day 3, morning
Methods for measuring cosmic-ray neutrons
High energy vs low energy
Neutron monitor
Neutron detectors – thermal, epithermal, fast
Instrument design for cosmic-ray method
Data acquisition, transmission, processing and dissemination
Data levels
COSMOS and similar networks

Day 3, afternoon: summary
Case studies
Discussion of problems
- reproduce computations for a COSMOS site of your choice;
Reports from assigned work
Summary of short course and discussions
Future directions in cosmic-ray hydrometrology research

Download schedule.

Enrolled Ph.D. students have first priority. Master students and other students will be considered if the course is not filled with Ph.D. students. Registrations from non-Ph.D.-students will be considered after the cut off date mentioned below.

Background of participants
Participants are expected to have a basic understanding of physics, chemistry and mathematics, a solid understanding of hydrology (or related science, such as soil physics, ecohydrology, meteorology), and they should be able to acquire (download) and manipulate large data sets using common software tools (such as Excel or Matlab).

Travel and accommodation
The course is free to attend for Ph.D. students and other students.

Participants are expected to cover their own travel, food, and accommodation expenses. Coffee and tea will be served during the course.

Hotel suggestions:

Budget: Hotel CabInn Scandinavia.

Mid-range: Hotel Østerport.


Participants (May 8th):

  • Mie Andreasen, University of Copenhagen
  • Paul Schattan, University of Innsbruck
  • Helene Hoffmann, University of Copenhagen
  • Lennart Ehlers, University of Copenhagen
  • Majken Looms Zibar, University of Copenhagen
  • Nicole Archer, British Geological Survey
  • Rena Meyer, University of Copenhagen
  • Gorka Mendiguren, GEUS
  • Landon Halloran, University of New South Wales
  • Cecilie Hermansen, Aarhus University
  • Karoline Edelvang, University of Copenhagen
  • Christina Stenvig Jensen, University of Copenhagen
  • Dan Karup, Aarhus University
  • Juan Pedro, University of Granada

Registrations from non-PhD students will be considered after the cut off date.

Copyright © 2024 HOBE - Center for Hydrology - Hydrological Observatory. All Rights Reserved.
Joomla! is Free Software released under the GNU General Public License.