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Title: Sensitivity of the global water cycle to the water-holding capacity of land

Abstract

The sensitivity of the global water cycle to the water-holding capacity of the plant-root zone of continental soils is estimated by simulations using a mathematical model of the general circulation of the atmosphere, with prescribed ocean surface temperatures and prescribed cloud. With an increase of the globally constant storage capacity, evaporation from the continents rises and runoff falls, because a high storage capacity enhances the ability of the soil to store water from periods of excess for later evaporation during periods of shortage. In addition, atmospheric feedbacks associated with higher precipitation and lower potential evaporation drive further changes in evaporation and runoff. Most changes in evaporation and runoff occur in the tropics and the northern middle-latitude rain belts. Global evaporation from land increases by 7 cm for each doubling of storage capacity. Sensitivity is negligible for capacity above 60 cm. In the tropics and in the extratropics,increased continental evaporation is split between increased continental precipitation and decreased convergence of atmospheric water vapor from ocean to land. In the tropics, this partitioning is strongly affected by induced circulation changes, which are themselves forced by changes in latent heating. In the northern middle and high latitudes, the increased continental evaporation moistens themore » atmosphere. This change in humidity of the atmosphere is greater above the continents than above the oceans, and the resulting reduction in the sea-land humidity gradient causes a decreased onshore transport of water vapor by transient eddies. Results here may have implications for problems in global hydrology and climate dynamics, including effects of water resource development on global precipitation, climatic control of plant rooting characteristics, climatic effects of tropical deforestation, and climate-model errors. 21 refs., 13 figs., 21 tabs.« less

Authors:
;  [1]
  1. Geological Survey, Princeton, NJ (United States)
Publication Date:
OSTI Identifier:
6792815
Resource Type:
Journal Article
Journal Name:
Journal of Climate; (United States)
Additional Journal Information:
Journal Volume: 7:4; Journal ID: ISSN 0894-8755
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; ATMOSPHERIC CIRCULATION; MATHEMATICAL MODELS; SOILS; PHYSICAL PROPERTIES; WATER; ECOLOGICAL CONCENTRATION; GLOBAL ASPECTS; STORAGE; HYDROGEN COMPOUNDS; OXYGEN COMPOUNDS; 540210* - Environment, Terrestrial- Basic Studies- (1990-); 540110

Citation Formats

Milly, P C.D., and Dunne, K A. Sensitivity of the global water cycle to the water-holding capacity of land. United States: N. p., 1994. Web. doi:10.1175/1520-0442(1994)007<0506:SOTGWC>2.0.CO;2.
Milly, P C.D., & Dunne, K A. Sensitivity of the global water cycle to the water-holding capacity of land. United States. https://doi.org/10.1175/1520-0442(1994)007<0506:SOTGWC>2.0.CO;2
Milly, P C.D., and Dunne, K A. 1994. "Sensitivity of the global water cycle to the water-holding capacity of land". United States. https://doi.org/10.1175/1520-0442(1994)007<0506:SOTGWC>2.0.CO;2.
@article{osti_6792815,
title = {Sensitivity of the global water cycle to the water-holding capacity of land},
author = {Milly, P C.D. and Dunne, K A},
abstractNote = {The sensitivity of the global water cycle to the water-holding capacity of the plant-root zone of continental soils is estimated by simulations using a mathematical model of the general circulation of the atmosphere, with prescribed ocean surface temperatures and prescribed cloud. With an increase of the globally constant storage capacity, evaporation from the continents rises and runoff falls, because a high storage capacity enhances the ability of the soil to store water from periods of excess for later evaporation during periods of shortage. In addition, atmospheric feedbacks associated with higher precipitation and lower potential evaporation drive further changes in evaporation and runoff. Most changes in evaporation and runoff occur in the tropics and the northern middle-latitude rain belts. Global evaporation from land increases by 7 cm for each doubling of storage capacity. Sensitivity is negligible for capacity above 60 cm. In the tropics and in the extratropics,increased continental evaporation is split between increased continental precipitation and decreased convergence of atmospheric water vapor from ocean to land. In the tropics, this partitioning is strongly affected by induced circulation changes, which are themselves forced by changes in latent heating. In the northern middle and high latitudes, the increased continental evaporation moistens the atmosphere. This change in humidity of the atmosphere is greater above the continents than above the oceans, and the resulting reduction in the sea-land humidity gradient causes a decreased onshore transport of water vapor by transient eddies. Results here may have implications for problems in global hydrology and climate dynamics, including effects of water resource development on global precipitation, climatic control of plant rooting characteristics, climatic effects of tropical deforestation, and climate-model errors. 21 refs., 13 figs., 21 tabs.},
doi = {10.1175/1520-0442(1994)007<0506:SOTGWC>2.0.CO;2},
url = {https://www.osti.gov/biblio/6792815}, journal = {Journal of Climate; (United States)},
issn = {0894-8755},
number = ,
volume = 7:4,
place = {United States},
year = {Fri Apr 01 00:00:00 EST 1994},
month = {Fri Apr 01 00:00:00 EST 1994}
}