| Title | Spatial variations and long-term trends of potential evaporation in Canada |
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| Author | Li, Z ; Wang, S; Li, J |
| Source | Scientific Reports vol. 10, 22089, 2020 p. 1-14, https://doi.org/10.1038/s41598-020-78994-9  Open Access |
| Image |  |
| Year | 2020 |
| Alt Series | Natural Resources Canada, Contribution Series 20210289 |
| Publisher | Springer Nature |
| Document | serial |
| Lang. | English |
| Media | digital; on-line |
| File format | pdf; html |
| Province | Canada; British Columbia; Alberta; Saskatchewan; Manitoba; Ontario; Quebec; New Brunswick; Nova Scotia; Prince Edward Island; Newfoundland and Labrador; Northwest Territories; Yukon; Nunavut;
Canada |
| NTS | 1; 2; 3; 10; 11; 12; 13; 14; 15; 16; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34; 35; 36; 37; 38; 39; 40; 41; 42; 43; 44; 45; 46; 47; 48; 49; 52; 53; 54; 55; 56; 57; 58; 59; 62; 63; 64; 65;
66; 67; 68; 69; 72; 73; 74; 75; 76; 77; 78; 79; 82; 83; 84; 85; 86; 87; 88; 89; 92; 93; 94; 95; 96; 97; 98; 99; 102; 103; 104; 105; 106; 107; 114O; 114P; 115; 116; 117; 120; 340; 560 |
| Subjects | geophysics; Nature and Environment; Science and Technology; remote sensing; satellite imagery; evaporation; climatology; climate effects; temperature; snow; ice; modelling; models; Ecological
Assimilation of Land and Climate Observations (EALCO) Model; Trends; Climate change; Hydrology; Water; Radiation; Wind; Methodology |
| Illustrations | sketch maps; plots; bar graphs; time series; tables |
| Program | Canada Centre
for Remote Sensing (CCRS) |
| Released | 2020 12 16 |
| Abstract | Assessing the status and trend of potential evaporation (PE) is essential for investigating the climate change impact on the terrestrial water cycle. Despite recent advances, evaluating climate change
impacts on PE using pan evaporation (Epan) data in cold regions is hindered by the unavailability of Epan measurements in cold seasons due to the freezing of water and sparse spatial distribution of sites. This study generated long-term PE datasets
in Canada for 1979-2016 by integrating the dynamic evolutions of water-ice-snow processes into estimation in the Ecological Assimilation of Land and Climate Observations (EALCO) model. The datasets were compared with Epan before the spatial
variations and trends were analyzed. Results show that EALCO PE and Epan measurements demonstrate similar seasonal variations and trends in warm seasons in most areas. Annual PE in Canada varied from 100 mm in the Northern Arctic to approximately
1000 mm in southern Canadian Prairies, southern Ontario, and East Coast, with about 600 mm for the entire landmass. Annual PE shows an increasing trend at a rate of 1.5-4 mm/year in the Northern Arctic, East, and West Canada. The increase is
primarily associated with the elevated air temperature and downward longwave and shortwave radiation, with some regions contributed by augmented wind speed. The increase of annual PE is mainly attributed to the augmentation of PE in warm seasons.
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| Summary | (Plain Language Summary, not published)
Potential evaporation (PE) quantifies the maximum water loss from the land or inland water surface to the air, when sufficient water is available and
water vapor can freely move. PE is controlled by climate variables, including solar radiation, wind, and air temperature. Hence, the variation in PE reflects climate change impacts on freshwater resources. PE can be directly measured using
specifically designed metal pan or indirectly estimated using physically based models. However, pan measurements are not available in winter in cold regions, because the frozen water discontinues observations. Pan measurements are point-based, may
not well represent PE's spatial variation in a region. In addition, the snow and ice processes complicated PE estimation using physical model in winter. For the reasons mentioned above, there is no temporally and spatially continuous PE dataset
available in Canada. Furthermore, there is no evaluation on climate change impacts on PE's spatiotemporal variations in entire Canada's landmass. Our study generated a long-term daily PE dataset for 1979-2016, compared the datasets with PE measured
using pan, and analyzed PE's variability and trends. The PE dataset was generated by integrating the evolutions of water-ice-snow processes into the simulation in the Ecological Assimilation of Land and Climate Observations (EALCO) model. Our results
show that EALCO PE dataset is reliable, indicated by similar seasonal variations and trends with pan measurements in warm seasons. Annual PE in Canada varied from 100 mm (millimetre) in the Northern Arctic to approximately 1000 mm in southern
Canadian Prairies, southern Ontario, and East Coast, with about 600 mm for the entire landmass. Climate change has increased annual PE in the Northern Arctic, East, and West Canada at a rate of 1.5-4 mm/year. The increase is primarily associated with
the increased air temperature and solar radiation, with some regions contributed by increased wind speed. |
| GEOSCAN ID | 328944 |
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