The impact of soil depth on land surface energy and water fluxes in the North American Monsoon region

Abstract A distributed hydrologic model is used to evaluate how runoff mechanisms—including infiltration excess (RI), saturation excess (RS), and groundwater exfiltration (RG)—influence the generation of streamflow and evapotranspiration (ET) in a mountainous region under the influence of the North American monsoon (NAM). The study site, the upper Sonora River basin (~9350 km2) in Mexico, is characterized by a wide range of terrain, soil, and ecosystem conditions obtained from best available data sources. Three meteorological scenarios are compared to explore the impact of spatial and temporal variations of meteorological characteristics on land surface processes and to identify the value of North American Land Data Assimilation System (NLDAS) forcing products in the NAM region. The following scenarios are considered for a 1-yr period: 1) a sparse network of ground-based stations, 2) raw forcing products from NLDAS, and 3) NLDAS products adjusted using available station data. These scenarios are discussed in light of spatial distributions of precipitation, streamflow, and runoff mechanisms during annual, seasonal, and monthly periods. This study identified that the mode of runoff generation impacts seasonal relations between ET and soil moisture in the water-limited region. In addition, ET rates at annual and seasonal scales were related to the runoff mechanism proportions, with an increase in ET when RS was dominant and a decrease in ET when RI was more important. The partitioning of runoff mechanisms also helps explain the monthly progression of runoff ratios in these seasonally wet hydrologic systems. Understanding the complex interplay between seasonal responses of runoff mechanisms and evapotranspiration can yield information that is of interest to hydrologists and water managers.

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Statistical and scaling properties of remotely-sensed soil moisture in two contrasting domains in the North American monsoon region

Journal of Arid Environments ◽

10.1016/j.jaridenv.2009.09.023 ◽

2010 ◽

Vol 74 (5) ◽

pp. 572-578 ◽

Cited By ~ 10

Author(s):

Giuseppe Mascaro ◽

Enrique R. Vivoni

Keyword(s):

Soil Moisture ◽

North American ◽

Remotely Sensed ◽

North American Monsoon ◽

Monsoon Region ◽

Scaling Properties ◽

The North

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Changes in Vegetation Condition and Surface Fluxes during NAME 2004

Journal of Climate ◽

10.1175/jcli4088.1 ◽

2007 ◽

Vol 20 (9) ◽

pp. 1810-1820 ◽

Cited By ~ 51

Author(s):

Christopher J. Watts ◽

Russell L. Scott ◽

Jaime Garatuza-Payan ◽

Julio C. Rodriguez ◽

John H. Prueger ◽

...

Keyword(s):

Surface Temperature ◽

Land Surface Temperature ◽

North American ◽

Land Surface ◽

Vegetation Index ◽

Surface Fluxes ◽

North American Monsoon ◽

Forest Site ◽

The North ◽

Dry Spell

Abstract The vegetation in the core region of the North American monsoon (NAM) system changes dramatically after the onset of the summer rains so that large changes may be expected in the surface fluxes of radiation, heat, and moisture. Most of this region lies in the rugged terrain of western Mexico and very few measurements of these fluxes have been made in the past. Surface energy balance measurements were made at seven sites in Sonora, Mexico, and Arizona during the intensive observation period (IOP) of the North American Monsoon Experiment (NAME) in summer 2004 to better understand how land surface vegetation change alters energy flux partitioning. Satellite data were used to obtain time series for vegetation indices and land surface temperature for these sites. The results were analyzed to contrast conditions before the onset of the monsoon with those afterward. As expected, precipitation during the 2004 monsoon was highly variable from site to site, but it fell in greater quantities at the more southern sites. Likewise, large changes in the vegetation index were observed, especially for the subtropical sites in Sonora. However, the changes in the broadband albedo were very small, which was rather surprising. The surface net radiation was consistent with the previous observations, being largest for surfaces that are transpiring and cool, and smallest for surfaces that are dry and hot. The largest evaporation rates were observed for the subtropical forest and riparian vegetation sites. The evaporative fraction for the forest site was highly correlated with its vegetation index, except during the dry spell in August. This period was clearly detected in the land surface temperature data, which rose steadily in this period to a maximum at its end.

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Regional Impacts of Irrigation in Mexico and the Southwestern United States on Hydrometeorological Fields in the North American Monsoon Region

Journal of Hydrometeorology ◽

10.1175/jhm-d-15-0223.1 ◽

2016 ◽

Vol 17 (12) ◽

pp. 2981-2995 ◽

Cited By ~ 7

Author(s):

Alex Mahalov ◽

Jialun Li ◽

Peter Hyde

Keyword(s):

North American ◽

Land Surface ◽

Large Scale ◽

Rainfall Variability ◽

Convective Available Potential Energy ◽

North American Monsoon ◽

Western Slope ◽

Surface Model ◽

Southern Mexico ◽

The Impact

Abstract In this study, the impacts of Mexican and southwestern U.S. agricultural and urban irrigation on North American monsoon (NAM) rainfall and other hydrometeorological fields are investigated using the Weather Research and Forecasting (WRF) Model by implementing an irrigation scheme into the WRF–land surface model. Taking the 2000–12 monsoon seasons as examples, multiple WRF simulations with irrigation are conducted by designing different crops’ maximum allowable water depletions (SWm). In comparison with gridded rainfall observations in urban and rural area, the WRF simulations with/without irrigation generally capture the observations very well, but with underestimation along the western slope of the Sierra Madre Occidental (SMO) and overestimation over southern Mexico. The simulations of WRF with irrigation are slightly improved over those without irrigation, compared with rainfall and sounding observations. Sensitivity studies reveal that the impact of irrigation on rainfall varies with location and NAM rainfall variability. Irrigation increases rainfall in eastern Arizona–western New Mexico and in northwestern Mexico because of the irrigation-induced increases of convective available potential energy (CAPE) and precipitable water. Overall, irrigation decreases rainfall in western Arizona, along the western slope of the SMO, and in central Mexico because of irrigation-induced increases of convective inhibition (CIN), decreases of CAPE, and/or large-scale water vapor divergence.

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The North American Monsoon GPS Transect Experiment 2013

Bulletin of the American Meteorological Society ◽

10.1175/bams-d-14-00250.1 ◽

2016 ◽

Vol 97 (11) ◽

pp. 2103-2115 ◽

Cited By ~ 11

Author(s):

Yolande L. Serra ◽

David K. Adams ◽

Carlos Minjarez-Sosa ◽

James M. Moker ◽

Avelino F. Arellano ◽

...

Keyword(s):

Water Vapor ◽

North American ◽

Water Cycle ◽

Precipitable Water ◽

Annual Rainfall ◽

North American Monsoon ◽

Atmospheric Sciences ◽

The North ◽

Northwestern Mexico ◽

The Impact

Abstract Northwestern Mexico experiences large variations in water vapor on seasonal time scales in association with the North American monsoon, as well as during the monsoon associated with upper-tropospheric troughs, mesoscale convective systems, tropical easterly waves, and tropical cyclones. Together these events provide more than half of the annual rainfall to the region. A sufficient density of meteorological observations is required to properly observe, understand, and forecast the important processes contributing to the development of organized convection over northwestern Mexico. The stability of observations over long time periods is also of interest to monitor seasonal and longer-time-scale variability in the water cycle. For more than a decade, the U.S. Global Positioning System (GPS) has been used to obtain tropospheric precipitable water vapor (PWV) for applications in the atmospheric sciences. There is particular interest in establishing these systems where conventional operational meteorological networks are not possible due to the lack of financial or human resources to support the network. Here, we provide an overview of the North American Monsoon GPS Transect Experiment 2013 in northwestern Mexico for the study of mesoscale processes and the impact of PWV observations on high-resolution model forecasts of organized convective events during the 2013 monsoon. Some highlights are presented, as well as a look forward at GPS networks with surface meteorology (GPS-Met) planned for the region that will be capable of capturing a wider range of water vapor variability in both space and time across Mexico and into the southwestern United States.

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