scholarly journals Influences of soil moisture and vegetation on convective precipitation forecasts over the United States Great Plains

2014 ◽  
Vol 119 (15) ◽  
pp. 9338-9358 ◽  
Author(s):  
Thomas W. Collow ◽  
Alan Robock ◽  
Wei Wu
2020 ◽  
Vol 21 (7) ◽  
pp. 1469-1484
Author(s):  
Yafang Zhong ◽  
Jason A. Otkin ◽  
Martha C. Anderson ◽  
Christopher Hain

AbstractDespite the key importance of soil moisture–evapotranspiration (ET) coupling in the climate system, limited availability of soil moisture and ET observations poses a major impediment for investigation of this coupling regarding spatiotemporal characteristics and potential modifications under climate change. To better understand and quantify soil moisture–ET coupling and relevant processes, this study takes advantage of in situ soil moisture observations from the U.S. Climate Reference Network (USCRN) for the time period of 2010–17 and a satellite-derived version of the evapotranspiration stress index (ESI), which represents anomalies in a normalized ratio of actual to reference ET. The analyses reveal strong seasonality and regional characteristics of the ESI–land surface interactions across the United States, with the strongest control of soil moisture on the ESI found in the southern Great Plains during spring, and in the north-central United States, the northern Great Plains, and the Pacific Northwest during summer. In drier climate regions such as the northern Great Plains and north-central United States, soil moisture control on the ESI is confined to surface soil layers, with subsurface soil moisture passively responding to changes in the ESI. The soil moisture–ESI interaction is more uniform between surface and subsurface soils in wetter regions with higher vegetation cover. These results provide a benchmark for simulation of soil moisture–ET coupling and are useful for projection of associated climate processes in the future.


2017 ◽  
Vol 30 (10) ◽  
pp. 3671-3685 ◽  
Author(s):  
Yaqiong Lu ◽  
Keith Harding ◽  
Lara Kueppers

Abstract Land–atmosphere coupling strength describes the degree to which the atmosphere responds (e.g., via changes in precipitation) to changes in the land surface state (e.g., soil moisture). The Midwest and Great Plains of the United States have been shown to be “hot spots” of coupling by many climate models and some observations. However, very few of the modeling studies have reported whether the climate models applied irrigation in the Midwest and Great Plains, where 24%–27% of farmland is irrigated, leaving open the question of whether irrigation affects current estimates of coupling strength. This study used a regional climate model that incorporated dynamic crop growth and precision irrigation (WRF3.3–CLM4crop) to investigate irrigation effects on land–atmosphere coupling strength. Coupling strength was quantified using multiple indices and the irrigated land-induced precipitation was tracked using a back trajectory method. The indices showed a consistent and significant decline in local coupling strength with irrigation in the Midwest and northern Great Plains. These reductions were due to increased soil moisture but decreased local precipitation and lower sensitivity of latent heat flux to soil moisture over irrigated regions. The back trajectories of water vapor transport confirmed that irrigation largely did not contribute to local precipitation. Water vapor from irrigated land was transported to the Midwest and U.S. Northeast where it fell as precipitation, suggesting that irrigation has a broader spatial impact on soil moisture–precipitation coupling than simply through local soil moisture–evapotranspiration coupling. The present study suggests that climate models without irrigation schemes may overestimate the land–atmosphere coupling strength over irrigated agricultural regions but underestimate coupling strength over neighboring nonirrigated regions.


2014 ◽  
Vol 18 (1) ◽  
pp. 139-154 ◽  
Author(s):  
T. W. Ford ◽  
E. Harris ◽  
S. M. Quiring

Abstract. Satellite-derived soil moisture provides more spatially and temporally extensive data than in situ observations. However, satellites can only measure water in the top few centimeters of the soil. Root zone soil moisture is more important, particularly in vegetated regions. Therefore estimates of root zone soil moisture must be inferred from near-surface soil moisture retrievals. The accuracy of this inference is contingent on the relationship between soil moisture in the near-surface and the soil moisture at greater depths. This study uses cross correlation analysis to quantify the association between near-surface and root zone soil moisture using in situ data from the United States Great Plains. Our analysis demonstrates that there is generally a strong relationship between near-surface (5–10 cm) and root zone (25–60 cm) soil moisture. An exponential decay filter is used to estimate root zone soil moisture using near-surface soil moisture derived from the Soil Moisture and Ocean Salinity (SMOS) satellite. Root zone soil moisture derived from SMOS surface retrievals is compared to in situ soil moisture observations in the United States Great Plains. The SMOS-based root zone soil moisture had a mean R2 of 0.57 and a mean Nash–Sutcliffe score of 0.61 based on 33 stations in Oklahoma. In Nebraska, the SMOS-based root zone soil moisture had a mean R2 of 0.24 and a mean Nash–Sutcliffe score of 0.22 based on 22 stations. Although the performance of the exponential filter method varies over space and time, we conclude that it is a useful approach for estimating root zone soil moisture from SMOS surface retrievals.


2020 ◽  
Vol 12 (20) ◽  
pp. 3434
Author(s):  
Maryia Halubok ◽  
Zong-Liang Yang

This study investigates how gross primary production (GPP) estimates can be improved with the use of solar-induced chlorophyll fluorescence (SIF) based on the interdependence between SIF, precipitation, soil moisture and GPP itself. We have used multi-year datasets from Global Ozone Monitoring Experiment-2 (GOME-2), Tropical Rainfall Measuring Mission (TRMM), European Space Agency Climate Change Initiative Soil Moisture (ESA CCI SM), and FLUXNET observations from ten stations in the continental United States. We have employed a GPP quantification framework that makes use of two factors whose influence on the SIF–GPP relationship was not evaluated previously—namely, differential plant sensitivity to water supply at different stages of its lifecycle and spatial variability patterns in SIF that are in contrast to those of GPP, precipitation, and soil moisture. It was found that over the Great Plains and Texas, fluorescence emission levels lag behind precipitation events from about two weeks for grasses to four weeks for crops. The spatial variability of SIF and GPP is shown to be characterized by different patterns: SIF demonstrates less variation over the same spatial extent as compared to GPP, precipitation and soil moisture. Thus, using newly introduced SIF–precipitation lead–lag relationships, we estimate GPP using SIF, precipitation and soil moisture data for grasses and crops over the US by applying the multiple linear regression technique. Our GPP estimates capture the drought impact over the US better than those from Moderate Resolution Imaging Spectroradiometer (MODIS). During the drought year of 2011 over Texas, our GPP values show a decrease by 50–75 gC/m2/month, as opposed to the normal yielding year of 2007. In 2012, a drought year over the Great Plains, we observe a significant reduction in GPP, as compared to 2007. Hence, estimating GPP using specific SIF–GPP relationships, and information on different plant functional types (PFTs) and their interactions with precipitation and soil moisture over the Great Plains and Texas regions can help produce more reasonable GPP estimates.


2004 ◽  
Vol 18 (3) ◽  
pp. 611-618 ◽  
Author(s):  
Bradley E. Fronning ◽  
George O. Kegode

Biennial wormwood has become a problem for soybean producers in the northern Great Plains of the United States. Research was conducted to evaluate control of biennial wormwood with preemergence (PRE) herbicides alone or followed by postemergence (POST) herbicides in 2000 and 2001 at Fargo, Leonard, and Wyndmere, ND. Favorable soil moisture conditions at Leonard resulted in continual emergence and greater densities of biennial wormwood, whereas the soil at Fargo and Wyndmere was dry and few biennial wormwood seedlings emerged at these locations. Biennial wormwood control with PRE herbicides was greater than 89% at Fargo and Wyndmere but was 80% or lower at Leonard. PRE biennial wormwood control was higher with flumetsulam than with sulfentrazone. When POST treatments were applied after PRE herbicides, biennial wormwood control 4 wk after treatment was 92% or better at Fargo and Wyndmere but was 76% or less at Leonard. The combination of PRE and POST herbicide treatments did not improve control greatly at Fargo or Wyndmere but at Leonard reduced the number of biennial wormwood plants.


2010 ◽  
Vol 10 (20) ◽  
pp. 9943-9952 ◽  
Author(s):  
R. C. Hudman ◽  
A. R. Russell ◽  
L. C. Valin ◽  
R. C. Cohen

Abstract. We examine the interannual variability in the NO2 column over North America measured by the Ozone Monitoring Instrument (OMI) in 2005–2008. By comparison to a model of soil NOx emissions driven by the North American Regional Reanalysis precipitation and 0–10 cm soil temperature fields, we show the source of this observed interannual variability over much of the central United States in June is fertilizer application. We find that dry, warm conditions followed by convective precipitation induces pulsed emissions of NOx over the agricultural Great Plains. In June 2006 we infer a 50% increase in soil NOx emission and a 30% increase in the tropospheric NO2 column relative to the June 2005–2008 mean. In a case-study of fertilized corn and soybean fields over SE South Dakota, we find an associated rain-induced pulsing event reaching 4.6×1015 molec cm−2, equivalent to a surface concentration of ~2 ppbv. We calculate that soil NOx emissions resulted in a mean daily maximum 8-h ozone enhancement over the agricultural Great Plains of 5 ppbv in June 2006 (with predicted events reaching 16 ppbv) compared with a mean enhancement of 3 ppbv for soil NOx in the years 2005–2008.


2010 ◽  
Vol 10 (5) ◽  
pp. 13029-13053 ◽  
Author(s):  
R. C. Hudman ◽  
A. R. Russell ◽  
L. C. Valin ◽  
R. C. Cohen

Abstract. We examine the interannual variability in the NO2 column over North America measured by the Ozone Monitoring Instrument (OMI) in 2005–2008. By comparison to a model of soil NOx emissions driven by the North American Regional Reanalysis precipitation and 0–10 cm soil temperature fields, we show the source of this observed interannual variability over much of the central United States in June is fertilizer application. We find that dry,warm conditions followed by convective precipitation induces pulsed emissions of NOx over the agricultural Great Plains. In June~2006 we infer a 50% increase in soil NOx emission and a 30% increase in the tropospheric NO2 column relative to the June 2005–2008 mean. In a case-study of fertilized corn and soybean fields over SE South Dakota, we find an associated rain-induced pulsing event reaching 4.6×1015 molec cm−2, equivalent to a surface concentration of ~2 ppbv. We calculate that soil NOx emissions resulted in a mean daily maximum 8-h ozone enhancement over the agricultural Great Plains of 5 ppbv in June~2006 (with predicted events reaching 16 ppbv) compared with a mean enhancement of 3 ppbv for soil NOx in the years 2005–2008.


Author(s):  
Pang-Wei Liu ◽  
Rajat Bindlish ◽  
Bin Fang ◽  
Venkat Lakshmi ◽  
Peggy E. O'Neill ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document