Physical Sciences and Mathematics Commons^™

Two Source Energy Balance Maize Evapotranspiration Estimates Using Close-Canopy Mobile Infrared Sensors And Upscaling Methods Under Variable Water Stress Conditions, A. Katimbo, D. Rudnick, W. Liang, K. Dejonge, T. Lo, T. Franz, Y. Ge, X. Qiao, H. Kabenge, H. N. Nakabuye

School of Natural Resources: Faculty Publications

No abstract provided.

Annual, Seasonal, And Diel Surface Energy Partitioning In The Semiarid Sand Hills Of Nebraska, Usa, Nathan C. Healey, Timothy J. Arkebauer, David P. Billesbach, John D. Lenters

School of Natural Resources: Faculty Publications

Study Region: The Nebraska Sand Hills consisting of four major land cover types: (1) lakes and wetlands (∼5% for both), (2) subirrigated meadows (∼10%), (3) dry valleys (∼20%), and (4) upland dunes (∼65%).

Study Focus: Examination of surface energy and water balances on multiple temporal scales with primary focus on latent heat flux (λE), and evapotranspiration (ET), to gain a better understanding of the annual, seasonal, and diel properties of surface energy partitioning among different Sand Hills ecosystems to improve regional water resource management. New Hydrological Insights for the Region: Based on surface energy and water balance measurements using Bowen …

Estimation Of Energy Balance Components Over A Drip-Irrigated Olive Orchard Using Thermal And Multispectral Cameras Placed On A Helicopter-Based Unmanned Aerial Vehicle (Uav), Samuel Ortega-Farias, Samuel Ortega-Salazar, Tomas Poblete, Ayse Kilic, Richard Allen, Carlos Poblete-Echeverria, Luis Ahumada-Orellana, Mauricio Zuniga, Daniel Sepulveda

School of Natural Resources: Faculty Publications

A field experiment was carried out to implement a remote sensing energy balance (RSEB) algorithm for estimating the incoming solar radiation (Rsi), net radiation (Rn), sensible heat flux (H), soil heat flux (G) and latent heat flux (LE) over a drip-irrigated olive (cv. Arbequina) orchard located in the Pencahue Valley, Maule Region, Chile (35^◦25'S; 71^◦44'W; 90 m above sea level). For this study, a helicopter-based unmanned aerial vehicle (UAV) was equipped with multispectral and infrared thermal cameras to obtain simultaneously the normalized difference vegetation index (NDVI) and surface temperature (Tsurface) at very high resolution (6 cm …

Green Roof Energy Balances For Native Grasses And Sedum, Chris Schwarz

School of Natural Resources: Dissertations, Theses, and Student Research

Green roofs offer a possible solution to reduce urban heat island effects caused by urbanization. Conventional green roofs use sedum for plant cover but growing evidence suggests native species offer better results for harsher environments. However, more information is needed to understand the potential of native species for green roof use in terms of survivability and cooling potential. This study was conducted from July 2013 through October 2013 to quantify the energy balance components for native grasses and sedum on a Midwestern green roof. The semi-intensive green roof located on the Larson Building parking garage in Lincoln, NE was used …

Eeflux: A Landsat-Based Evapotranspiration Mapping Tool On The Google Earth Engine, Richard Allen, Charles Morton, Baburao Kamble, Ayse Kilic, Justin Huntington, David Thau, Noel Gorelick, Tyler Erickson, Rebecca Moore, Ricardo Trezza, Ian C. Ratcliffe, Clarence Robison

School of Natural Resources: Faculty Publications

“EEFlux” is an acronym for ‘Earth Engine Evapotranspiration Flux.’ EEFlux is based on the operational surface energy balance model “METRIC” (Mapping ET at high Resolution with Internalized Calibration), and is a Landsat-imagebased process. Landsat imagery supports the production of ET maps at resolutions of 30 m, which is the scale of many human-impacted and human-interest activities including agricultural fields, forest clearcuts and vegetation systems along streams. ET over extended time periods provides valuable information regarding impacts of water consumption on Earth resources and on humans. EEFlux uses North American Land Data Assimilation System hourly gridded weather data collection for energy …

Application Of Remote Sensing For Quantifying And Mapping Surface Energy Fluxes In South Central Nebraska: Analyses With Respect To Field Measurements, Vivek Sharma, Suat Irmak, Ayse Kilic, Denis Mutibwa

School of Natural Resources: Faculty Publications

Large-scale quantification of crop evapotranspiration (ETc) from various vegetation surfaces can aid in planning, managing, and allocating water resources. Field measurement of surface energy fluxes, including ETc, remains (and should remain) a crucial process for calibration and validation of satellite/remote sensing-based methods, which can provide important supporting information for water balance assessments and for analyzing the spatial distribution of energy fluxes on large scales. The Surface Energy Balance System (SEBS) was evaluated in estimating surface energy fluxes in south central Nebraska using Landsat imagery and meteorological data. SEBS-estimated surface energy fluxes were compared to Bowen Ratio Energy Balance System (BREBS) …

Water And Energy Balance Response Of A Riparian Wetland To The Removal Of Phragmites Australis, Phillip Mykleby

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Vegetation and climate both play integral roles in water availability, particularly for arid to semi-arid regions. Changes in these variables can lead to extreme shortages in water for regions that rely on water for crop irrigation (i.e., the Great Plains). The objective of this study is to evaluate the impacts of vegetation on water availability in the Republican River basin in central Nebraska. Decreases in streamflow have been observed in the river basin for many years and, as a result, an invasive riparian plant species (Phragmites australis) is being removed in an effort to reduce evapotranspiration and reclaim …

Hurricane Disturbance And Recovery Of Energy Balance, Co2 Fluxes And Canopy Structure In A Mangrove Forest Of The Florida Everglades, Jordan G. Barr, Vic Engel, Thomas J. Smith, José D. Fuentes

United States Geological Survey: Staff Publications

Eddy covariance (EC) estimates of carbon dioxide (CO2) fluxes and energy balance are examined to investigate the functional responses of a mature mangrove forest to a disturbance generated by Hurricane Wilma on October 24, 2005 in the Florida Everglades. At the EC site, high winds from the hurricane caused nearly 100% defoliation in the upper canopy and widespread tree mortality. Soil temperatures down to −50 cm increased, and air temperature lapse rates within the forest canopy switched from statically stable to statically unstable conditions following the disturbance. Unstable conditions allowed more efficient transport of water vapor and CO₂ from …

Climatic Controls On The Summertime Energy Balance Of A Thermokarst Lake In Northern Alaska: Short-Term, Seasonal, And Interannual Variability, Brittany L. Potter

School of Natural Resources: Dissertations, Theses, and Student Research

Shallow, thermokarst lakes that develop atop permafrost are a prominent landscape feature on the Arctic Coastal Plain (ACP) of northern Alaska. The ACP is vulnerable to ongoing climate change and landscape modification, as thousands of thaw lakes and ponds are impacted by changes in temperature, precipitation, thawing permafrost, and human activity. Although summer in the Arctic is short, incoming solar radiation and lake evaporation are relatively high, and both factors play a significant role in the landscape water balance. Furthermore, lake evaporation is anticipated to increase as the ice-free season lengthens and water temperatures become warmer. To improve our understanding …

Estimation Of Land Surface Evapotranspiration With A Satellite Remote Sensing Procedure, Ayse Kilic, Ian Ratcliffe, Pariskhit Ranade, Kenneth Hubbard, Ramesh K. Singh, Babuarao Kamble, Jeppe Kjaersgaard

School of Natural Resources: Faculty Publications

There are various methods available for estimating magnitude and trends of evapotranspiration. Bowen ratio energy balance system and eddy correlation techniques offer powerful alternatives for measuring land surface evapotranspiration. In spite of the elegance, high accuracy, and theoretical attractions of these techniques for measuring evapotranspiration, their practical use over large areas can be limited due to the number of sites needed and the related expense. Application of evapotranspiration mapping from satellite measurements can overcome the limitations. The objective of this study was to utilize the METRIC^TM (Mapping Evapotranspiration at High Resolution using Internalized Calibration) model in Great Plains environmental …

Estimation Of Land Surface Evapotranspiration With A Satellite Remote Sensing Procedure, Ayse Kilic, Ian Ratcliffe, Pariskhit Ranade, Kenneth Hubbard, Ramesh K. Singh, Babuarao Kamble, Jeppe Kjaersgaard

Great Plains Research: A Journal of Natural and Social Sciences

There are various methods available for estimating magnitude and trends of evapotranspiration. Bowen ratio energy balance system and eddy correlation techniques offer powerful alternatives for measuring land surface evapotranspiration. In spite of the elegance, high accuracy, and theoretical attractions of these techniques for measuring evapotranspiration, their practical use over large areas can be limited due to the number of sites needed and the related expense. Application of evapotranspiration mapping from satellite measurements can overcome the limitations. The objective of this study was to utilize the METRIC^TM (Mapping Evapotranspiration at High Resolution using Internalized Calibration) model in Great Plains environmental …

Can Climate Sensitivity Be Estimated From Short-Term Relationships Of Top-Of-Atmosphere Net Radiation And Surface Temperature?, Bing Lin, Qilong Min, Wenbo Sun, Yongxiang Hu, Tai-Fang Fan

United States National Aeronautics and Space Administration: Publications

Increasing the knowledge in climate radiative feedbacks is critical for current climate studies. This work focuses on short-term relationships between global mean surface temperature and top-of-atmosphere (TOA) net radiation. The relationships may be used to characterize the climate feedback as suggested by some recent studies. As those recent studies, an energy balance model with ocean mixed layer and both radiative and non-radiative heat sources is used here. The significant improvement of current model is that climate system memories are considered.

Based on model simulations, short-term relationship between global mean surface temperature and TOA net radiation (or the linear striation feature …

Seasonal Energy And Water Balance Of A Phragmites Australis-Dominated Wetland In The Republican River Basin Of South-Central Nebraska (Usa), John D. Lenters, Gregory J. Cutrell, Erkan Istanbulluoglu, Durelle T. Scott, Kyle S. Herrman, Dean E. Eisenhauer

School of Natural Resources: Faculty Publications

energy and water balance, especially in dry climatic regions, can have a significant impact on local water availability and, therefore, water resource management. The purpose of this study is to quantify the energy and water balance of a riparian wetland in a subhumid region of the central US, as well as the role of seasonal climate variability and vegetation phenology. The site is located in the Republican River basin in south-central Nebraska, where decreases in streamflow have been observed in recent decades. In an effort to reduce consumptive water use from evapotranspiration (ET), and thereby reclaim surface water, invasive species …

Comparison And Analysis Of Empirical Equations For Soil Heat Flux For Different Cropping Systems And Irrigation Methods, Ayse Kilic, R. K. Singh, Elizabeth A. Walter-Shea, Shashi Verma, Andrew E. Suyker

School of Natural Resources: Faculty Publications

We evaluated the performance of four models for estimating soil heat flux density (G) in maize (Zea mays L.) and soybean (Glycine max L.) fields under different irrigation methods (center‐pivot irrigated fields at Mead, Nebraska, and subsurface drip irrigated field at Clay Center, Nebraska) and rainfed conditions at Mead. The model estimates were compared against measurements made during growing seasons of 2003, 2004, and 2005 at Mead and during 2005, 2006, and 2007 at Clay Center. We observed a strong relationship between the G and net radiation (R_n) ratio (G/R_n) and the normalized difference …

Spectral Data-Based Estimation Of Soil Heat Flux, Ramesh K. Singh, Ayse Kilic, Elizabeth Walter-Shea, Shashi B. Verma, Andrew E. Suyker

School of Natural Resources: Faculty Publications

Numerous existing spectral‐based soil heat flux (G) models have shown wide variation in performance for maize and soybean cropping systems in Nebraska, indicating the need for localized calibration and model development. The objectives of this article are to develop a semi‐empirical model to estimate G from a normalized difference vegetation index (NDVI) and net radiation (R_n) for maize (Zea mays L.) and soybean (Glycine max L.) fields in the Great Plains, and present the suitability of the developed model to estimate G under similar and different soil and management conditions. Soil heat fluxes measured in both …

Seasonal Energy And Water Balance Of A Phragmites Australis-Dominated Wetland In The Republican River Basin (Southwestern Nebraska, Usa), Gregory J. Cutrell

School of Natural Resources: Dissertations, Theses, and Student Research

Climate and vegetation can dramatically alter the water cycle on local to regional scales. A change in the surface energy and water balance, especially in arid regions, can have significant impacts on local water availability and, therefore, water resource management. The purpose of this study is to understand the role of climate and vegetation in the energy and water balance of a riparian wetland in the central Great Plains. The site is located near the Republican River in southwestern Nebraska, where decreases in streamflow have been observed in recent decades. In an effort to reduce consumptive use from evapotranspiration (ET), …

Manual: Measurement Of Evapotranspiration By The Bowen Ratio Energy Balance Method, Joon Kim, Shashi Verma

School of Natural Resources: Faculty Publications

The Bowen ratio energy balance method has been widely used by many researchers to estimate the fluxes of water vapor and sensible heat between crops and atmosphere. The energy balance for the crop canopy can be expressed as Rn + G + H + LE + PS + M = 0 (1) where Rn is net radiation, G is soil surface heat flux, H is sensible heat flux and LE is latent heat flux.

Resistance-Energy Balance Method For Predicting Evapotranspiration: Determination Of Boundary Layer Resistance And Evaluation Of Error Effects, S. B. Verma, N. J. Rosenberg, B. L. Blad

School of Natural Resources: Faculty Publications

No abstract provided.

Accuracy Of Lysimetric, Energy Balance, And Stability-Corrected Aerodynamic Methods Of Estimating Above-Canopy Flux Of Co2, S. B. Verma, N. J. Rosenberg

School of Natural Resources: Faculty Publications

No abstract provided.