Atmospheric Pressure
type: Dataset
description: Contained within the 3rd Edition (1957) of the Atlas of Canada is a plate that shows four maps, one for each of January, April, July and October showing mean sea-level pressure in millibars. These maps were prepared from atmospheric pressure readings taken daily at 00, 06, 12 and 18 hours G.M.T. during the period 1940 to 1949 inclusive, except for the area north of 72.5 degrees N, where the period was 1948 to 1953 inclusive (and for which the results were adjusted to the 1940 to 1949 period). Ten mean sea-level pressure maps were drawn for each of the selected months in these periods using averages of the observed pressure. Then a grid system was superimposed over these maps and the pressure at 200 points read off. From these figures the mean maps reproduced here were drawn.
issued: 2025-11-24T21:37:50.866467
modified: 2025-11-24T21:37:50.866472
contact point: Organization
keyword: AmeriGEO
keyword: AmeriGEOSS
keyword: CKAN
keyword: Canada
keyword: GEO
keyword: GEOSS
keyword: National
keyword: North America
landing page: 0c3210f8-5226-5d73-8b8a-35d8633b69b2'}

Download the French PDF through HTTP
type: Distribution
format: PDF
issued: 2017-01-26T11:24:09.840178
modified: 2025-11-24T21:37:50.860371
access URL: http://ftp.geogratis.gc.ca/pub/nrcan_rncan/raster/atlas_3_ed/fra/environment/climate/019.pdf

Download the French JPG through HTTP
type: Distribution
format: JPEG
issued: 2017-01-26T11:24:09.840165
modified: 2025-11-24T21:37:50.859988

Download the English JPG through HTTP
type: Distribution
format: JPEG
issued: 2017-01-26T11:24:09.840104
modified: 2025-11-24T21:37:50.859168

Download the English PDF through HTTP
type: Distribution
format: PDF
issued: 2017-01-26T11:24:09.840151
modified: 2025-11-24T21:37:50.859594
access URL: http://ftp.geogratis.gc.ca/pub/nrcan_rncan/raster/atlas_3_ed/eng/environment/climate/019.pdf

Canada
type: Agent