This site was updated on 5 March 2021.

Canada is a long-standing participant in the IAEA/WMO Global Network for Isotopes in Precipitation (GNIP) program, aimed at documentation and understanding of the distribution of water isotope tracers (stable ¹⁸O and ²H, and radioactive ³H) in global precipitation.  Such data and knowledge about the natural isotopic labelling that occurs as a result of phase changes in the hydrologic cycle are playing increasingly important roles in water and climate research, including incorporation of isotope tracers into hydrologic models, ecosystem models, and atmospheric general circulation models (GCMs), and the need for new tools to supplement traditional hydrometric and hydrometeorological techniques in water resources analysis. 

Composite monthly samples have been collected at Ottawa, Ontario, for ~70 years, providing one of the longest continuous time-series records in the world of d¹⁸ O, d²H, and ³H in precipitation at one site, making Ottawa a key North American reference station [1].  Collection at Ottawa has also been joined at intervals by sampling campaigns at individual stations or over limited networks, generally for the purposes of specific research projects.  Although many of these data are also incorporated into the GNIP database, knowledge about the distribution of water isotopes in precipitation in Canada remains patchy in both space and time, and insufficient to support the needs of current and future water and climate research. 

A cooperative venture was initiated in 1997 between university and government researchers and Environment Canada's Meteorological Service that established an operational Canadian Network for Isotopes in Precipitation - CNIP which carried out monthly sampling between 1997 and 2015 at 17 stations across Canada in the Canadian Air and Precipitation Monitoring Network (CAPMoN).  These new stations were chosen to supplement Ottawa and a network of stations in the North that had been operating for several years as an initiative of Professor Fred Michel (Carleton University) and the Environmental Isotope Laboratory (University of Waterloo), in collaboration with on-site MSC personnel.

CNIP provided the first fairly comprehensive spatial coverage for the entire country allowing study of fundamental linkages between the isotopic composition of precipitation and synoptic climatology and will be used to develop a more permanent future network.

All analyses were carried out at the University of Waterloo Environmental Isotope Laboratory , which has had a long affiliation with the GNIP program.  Future plans for CNIP are under discussion by the Commitee on Isotopic Tracers of the Canadian Geophysical Union - Hydrology Section . Summaries of the network and recent research have been published [2,3].

REFERENCES
[1] Rozanski,K.,Araguás-Araguás,L., and Gonfiantini, R. 1993. Isotopic patterns in modern precipitation. Geophysical Monograph 78, American Geophysical Union.
[2] Birks, S. J., Gibson, J.J, 2009. Isotope Hydrology Research in Canada, 2003-2007. Canadian Water Resources Journal 34 (2): 163-176. [PDF 538 Kb]
[3] Gibson, J.J., Edwards, T.W.D., Birks, S.J., St. Amour, N.A., Buhay, W., McEachern, P., Wolfe, B.B., Peters, D.L., 2005. Progress in Isotope Tracer Hydrology in Canada. Hydrological Processes 19, 303-327. [PDF 966Mb].