Life Sciences Commons^™

Asparagus (Asparagus Officinalis L.) Root Distribution: Cultivar Differences In Mature Plantings, Daniel Drost

Plants, Soils, and Climate Faculty Publications

Annual plant growth patterns and seasonal conditions have both been shown to influence asparagus (Asparagus officinalis L.) root development over time. Root biomass and distribution changes in mature asparagus cultivars are herein illustrated and described. Asparagus root length density and biomass were estimated from soil cores using a systematic field sampling approach each spring. Soil cores (0.9 m deep) were divided into 0.15 m lengths and fleshy roots collected from the soil. Root length density and dry weights were determined and root distribution maps generated from collected data. As asparagus plantings matured, the sampling year had a significant influence …

Assessing Within-Field Variation In Alfalfa Leaf Area Index Using Uav Visible Vegetation Indices, Keegan Hammond, Ruth Kerry, Ryan R. Jensen, Ross Spackman, April Hulet, Bryan G. Hopkins, Matt A. Yost, Austin P. Hopkins, Neil C. Hansen

Plants, Soils, and Climate Faculty Publications

This study examines the use of leaf area index (LAI) to inform variable-rate irrigation (VRI) for irrigated alfalfa (Medicago sativa). LAI is useful for predicting zone-specific evapotranspiration (ET_c). One approach toward estimating LAI is to utilize the relationship between LAI and visible vegetation indices (VVIs) using unmanned aerial vehicle (UAV) imagery. This research has three objectives: (1) to measure and describe the within-field variation in LAI and canopy height for an irrigated alfalfa field, (2) to evaluate the relationships between the alfalfa LAI and various VVIs with and without field average canopy height, and (3) to …

Selenium Removal By Sediments And Plants At The Constructed Pariette Wetlands, Utah (Usa), Colleen P. Jones, Michael Amacher, Paul R. Grossl, Astrid R. Jacobson

Plants, Soils, and Climate Faculty Publications

Selenium (Se) contamination of public lands and water is a result of irrigated agriculture and mining activities in areas rich in Se geologic deposits. Pariette Draw is part of the northern Colorado Plateau and is an area of concern for Se contamination in the Pariette Wetlands. Pariette Wetlands, a wetland built in the 1970s to provide wildlife habitat, is distinguished by its arid climate and a short growing season of hot dry summers followed by cold winters with several months below freezing. An understanding of how Se is mobilized and removed within the wetland will provide management strategies that minimize …

Irrigation Zone Delineation And Management With A Field-Scale Variable Rate Irrigation System In Winter Wheat, Elisa A. Flint, Bryan G. Hopkins, Jeffery D. Svedin, Ruth Kerry, Matthew J. Heaton, Ryan R. Jensen, Colin S. Campbell, Matt Yost, Neil C. Hansen

Plants, Soils, and Climate Faculty Publications

Understanding spatial and temporal dynamics of soil water within fields is critical for effective variable rate irrigation (VRI) management. The objectives of this study were to develop VRI zones, manage irrigation rates within VRI zones, and examine temporal differences in soil volumetric water content (VWC) from irrigation events via soil sensors across zones. Five irrigation zones were delineated after two years (2016 and 2017) of yield and evapotranspiration (ET) data collection. Soil sensors were placed within each zone to give real time data of VWC values and assist in irrigation decisions within a 23 ha field of winter wheat ( …

Biochar Influences Phytochemical Concentrations Of Viola Cornuta Flowers, Abishkar Regmi, Shital Poudyal, Sukhbir Singh, Cade Coldren, Naima Moustaid-Moussa, Catherine Simpson

Plants, Soils, and Climate Faculty Publications

Edible flowers are a rich source of phytochemicals with potential health benefits. Yet, changes in production practices can influence the phytochemical composition of edible flowers. Practices such as the addition of biochar have been used to affect growing media properties as well as to conserve peat resources. However, there is little known about how biochar affects the phytochemical composition of edible flowers. To determine if biochar affects phytochemicals in Viola cornuta, four cultivars were subjected to different rates of biochar, with and without fertilizer. At the rate of 10% biochar and without fertilizer application, flower polyphenol and flavonoid concentrations …

Hucopia: An Atlas Of Human Vs. Sars-Cov-2 Interactome And The Comparative Analysis With Other Coronaviridae Family Viruses, Naveen Duhan, Rakesh Kaundal

Plants, Soils, and Climate Faculty Publications

SARS-CoV-2, a novel betacoronavirus strain, has caused a pandemic that has claimed the lives of nearly 6.7M people worldwide. Vaccines and medicines are being developed around the world to reduce the disease spread, fatality rates, and control the new variants. Understanding the protein-protein interaction mechanism of SARS-CoV-2 in humans, and their comparison with the previous SARS-CoV and MERS strains, is crucial for these efforts. These interactions might be used to assess vaccination effectiveness, diagnose exposure, and produce effective biotherapeutics. Here, we present the HuCoPIA database, which contains approximately 100,000 protein-protein interactions between humans and three strains (SARS-CoV-2, SARS-CoV, and MERS) …

Responses Of Extreme Discharge To Changes In Surface-Air And Dewpoint Temperatures In Utah: Seasonality And Mechanisms, Timothy E. Wright, Jacob Stuivenvolt-Allen, Grace Affram, Nahid A. Hasan, Cody Ratterman, Wei Zhang

Plants, Soils, and Climate Faculty Publications

The changes in stream discharge extremes due to temperature and seasonality are key metrics in assessing the effects of climate change on the hydrological cycle. While scaling is commonly applied to temperature and precipitation due to the physical connections between temperature and moisture (i.e., Clausius–Clapeyron), the scaling rate of stream discharge extremes to air and dewpoint temperatures has not been evaluated. To address this challenge, we assess the scaling rates between stream discharge and air temperature and between stream discharge and dewpoint temperature in Utah using a well-designed statistical framework. While there are deviations from the Clausius–Clapeyron (CC) relationship in …

Atmospheric Rivers Impacting Northern California Exhibit A Quasi-Decadal Frequency, Jacob Stuivenvolt-Allen, Shih-Yu Simon Wang, Zachary Johnson, Yoshimitsu Chikamoto

Plants, Soils, and Climate Faculty Publications

Periods of water surplus and deficit in Northern California follow a pronounced quasi-decadal cycle. This cycle is largely driven by the frequency of atmospheric rivers (ARs), affecting the region’s wet and dry periods. Our analyses demonstrate that the quasi-decadal cycle of AR frequency relies on moisture transport associated with the position and intensity of the Aleutian Low. In observations, the Aleutian Low is shown to covary with tropical Pacific sea surface temperature anomalies. A modeling experiment, which incorporates ocean observations from the equatorial Pacific into the fully coupled climate model, provides support that the quasi-decadal cycle of the Aleutian Low …

Subseasonal Prediction For Bloom Dates Of Tart Cherries In Utah And Michigan, Usa: Merging Phenological Models With Cfsv2 Forecast, Parichart Promchote, Shih-Yu (Simon) Wang, Brent Black, Paul Johnson

Plants, Soils, and Climate Faculty Publications

Temperate fruit trees require chilling for rest completion, followed by sufficient heat accumulation for onset of growth and bloom. The application of phenological models to predict bloom dates has been widely used in orchard management. Examples of such application include selecting adapted cultivars less prone to early bloom, predicting needs for frost protection, and preventing damage from late spring freezes. This study merged the Utah (chill) and ASYMCUR (forcing) phenological models by combining chill units and heat units (measured in growing degree hours) to predict bloom dates of tart cherries (Prunus cerasus L.) in Utah and Michigan, the top …

Formate Dehydrogenase (Fdh1) Localizes To Both Mitochondria And Chloroplast To Play A Role In Host And Nonhost Disease Resistance, Seonghee Lee, Ramu S. Vemanna, Sunhee Oh, Clemencia M. Rojas, Youngjae Oh, Amita Kaundal, Taegun Kwon, Hee-Kyung Lee, Muthappa Senthil-Kumar, Kirankumar S. Mysore

Plants, Soils, and Climate Faculty Publications

Nonhost disease resistance is the most common type of plant defense mechanism against potential pathogens. In this study, the metabolic enzyme formate dehydrogenase (FDH1) was identified to be involved in nonhost disease resistance in Nicotiana benthamiana and Arabidopsis thaliana. In Arabidopsis, AtFDH1 was highly upregulated in response to both host and nonhost bacterial pathogens. Arabidopsis Atfdh1 mutants were compromised in nonhost resistance, basal resistance, and gene-for-gene resistance. The expression patterns of salicylic acid (SA) and jasmonic acid (JA) marker genes after pathogen infections in Atfdh1 mutant indicated that SA is most likely involved in the FDH1-mediated plant defense response to …

In Vitro Digestibility Of Mountain-Grown Irrigated Perennial Legume, Grass And Forb Forages Is Influenced By Elevated Non-Fibrous Carbohydrates And Plant Secondary Compounds, Yunhua Zhang, Jennifer W. Macadam, Juan J. Villalba, Xin Dai

Plants, Soils, and Climate Faculty Publications

BACKGROUND

Perennial legumes cultivated under irrigation in the Mountain West USA have non‐fibrous carbohydrate (NFC) concentrations exceeding 400 g kg−1, a level commonly found in concentrate‐based ruminant diets. Our objective was to determine the influence of NFC concentration and plant secondary compounds on in vitro rumen digestion of grass, legume and forb forages compared with digestion of their isolated neutral detergent fiber (NDF) fraction. Forages were composited from ungrazed paddocks of rotationally stocked, irrigated monoculture pastures between May and August 2016, frozen in the field, freeze‐dried, and ground.

RESULTS

The maximum rate (RMax) of gas production was greater for the …

Chromosomal Evolution And Apomixis In The Cruciferous Tribe Boechereae, Terezie Mandáková, Petra Hloušková, Michael D. Windham, Thomas Mitchell-Olds, Kaylynn Ashby, Bo Price, John Carman, Martin A. Lysak

Plants, Soils, and Climate Faculty Publications

The mustard family (Brassicaceae) comprises several dozen monophyletic clades usually ranked as tribes. The tribe Boechereae plays a prominent role in plant research due to the incidence of apomixis and its close relationship to Arabidopsis. This tribe, largely confined to western North America, harbors nine genera and c. 130 species, with >90% of species belonging to the genus Boechera. Hundreds of apomictic diploid and triploid Boechera hybrids have spurred interest in this genus, but the remaining Boechereae genomes remain virtually unstudied. Here we report on comparative genome structure of six genera (Borodinia, Cusickiella, Phoenicaulis, …

Genetic Mapping Of The Common And Dwarf Bunt Resistance Gene Bt12 Descending From The Wheat Landrace Pi119333, Almuth Elise Muellner, Babur Eshonkulov, Julia Hagenguth, Bernadette Pachler, Sebastian Michel, Maria Buerstmayr, David Hole, Hermann Buerstmayr

Plants, Soils, and Climate Faculty Publications

Common bunt (CB), caused by Tilletia caries and T. foetida, and dwarf bunt (DB), caused by T. controversa, are particularly destructive diseases of wheat grown under organic (low-input) production conditions and negatively affect both grain yield and quality. A total of 16 race specific bunt resistance genes have been proposed to date. Thereof, only Bt9 and Bt10 have been mapped so far. A mapping and two validation populations comprising 176 recombinant inbred lines were evaluated for CB and DB in artificially inoculated field trials. The mapping population was derived from the cross of the Bt12 carrier PI119333 and …

From Physics To Fixtures To Food: Current And Potential Led Efficacy, Paul Kusuma, P. Morgan Pattison, Bruce Bugbee

Plants, Soils, and Climate Faculty Publications

Light-emitting diodes (LEDs) have enabled a historic increase in the conversion of electric energy to photons, but this is approaching a physical limit. The theoretical maximum efficiency occurs when all input energy is converted to energy in photosynthetic photons. Blue LEDs can be 93% efficient, phosphor-converted “whites” 76% efficient, and red LEDs 81% efficient. These improvements open new opportunities for horticultural lighting. Here we review (1) fundamental physics and efficiency of LEDs, (2) the current efficacy of LEDs, (3) the effect of spectral quality on crop yield, and (4) the potential efficacy of horticultural fixtures. Advances in the conversion of …

On Tanzania’S Precipitation Climatology, Variability, And Future Projection, Krishna Borhara, Binod Pokharel, Brennan L. Bean, Liping Deng, Shih-Yu (Simon) Wang

Plants, Soils, and Climate Faculty Publications

We investigate historical and projected precipitation in Tanzania using observational and climate model data. Precipitation in Tanzania is highly variable in both space and time due to topographical variations, coastal influences, and the presence of lakes. Annual and seasonal precipitation trend analyses from 1961 to 2016 show maximum rainfall decline in Tanzania during the long rainy season in the fall (March–May), and an increasing precipitation trend in northwestern Tanzania during the short rainy season in the spring (September–November). Empirical orthogonal function (EOF) analysis applied to Tanzania’s precipitation patterns shows a stronger correlation with warmer temperatures in the western Indian Ocean …

Short-Term Nitrogen Fertilization Affects Microbial Community Composition And Nitrogen Mineralization Function In An Agricultural Soil, Yang Ouyang, Jeanette M. Norton

Plants, Soils, and Climate Faculty Publications

Soil extracellular enzymes play a significant role in the N mineralization process. However, few studies have documented the linkage between enzyme activity and the microbial community that performs the function. This study examined the effects of inorganic and organic N fertilization on soil microbial communities and their N mineralization functions over 4 years. Soils were collected from silage corn field plots with four contrasting N treatments: control (no additional N), ammonium sulfate (AS; 100 and 200 kg of N ha⁻¹), and compost (200 kg of N ha⁻¹). Illumina amplicon sequencing was used to comprehensively assess the …

Association Of Diurnal Rainfall In Northeastern Tibetan Plateau With The Retreat Of The South Asian High, Lin Zhao, Shih-Yu Simon Wang, Chi-Hua Wu, Sebastian Los, Shihua Lyu, Xianhong Meng, Lijuan Wen, Siqiong Luo, Yinhuan Ao, Zhaoguo Li

Plants, Soils, and Climate Faculty Publications

The characteristics of intense diurnal precipitation occurring beneath the South Asian High (SAH) are diagnosed in the summer monsoon season from 2010 to 2015 using observational data. The diagnostics indicate that summer nighttime rainfall events in the northeastern Tibetan Plateau can intensify towards the end of the monsoon period. By defining a transition index to identify the transition day during which the episodes of diurnal convection start to decline, daily thermodynamic properties and precipitation from each year were composited before and after the transition date. The analysis reveals that warmer air, increased moisture, and stronger upward velocity are present in …

Genetic Characterization And Genome-Wide Association Mapping For Dwarf Bunt Resistance In Bread Wheat Accessions From The Usda National Small Grains Collection, Tyler Gordon, Rui Wang, David Hole, Harold Bockelman, J. Michael Bonman, Jianli Chen

Plants, Soils, and Climate Faculty Publications

Key message

Dwarf bunt-resistant bread wheat accessions and SNP markers associated with DB resistance identified in this study are valuable resources for characterization and deployment of DB resistance in bread wheat.

Abstract

Dwarf bunt (DB), caused by Tilletia controversa J.G. Kühn, can significantly reduce grain yield and quality on autumn-sown wheat in regions with prolonged snow cover. DB can be managed with the use of resistant cultivars. The objectives of the present study were to characterize DB resistance in a large set of bread wheat accessions from the National Small Grains Collection and use a genome-wide association study approach to …

Morphological And Physiological Responses Of Cornus Alba To Salt And Drought Stresses Under Greenhouse Conditions, Qiang Liu, Youping Sun, James Altland, Genhua Niu

Plants, Soils, and Climate Faculty Publications

Tatarian dogwood (Cornus alba) is an ornamental shrub with white fruits, creamy-white flowers, and red stems in fall through late winter and is widely used in residential landscape, public parks, and botanical gardens. Two greenhouse experiments were conducted to characterize the survival, morphological, aesthetic, and physiological responses of tatarian dogwood seedlings to salinity and drought stresses. In Expt. 1, tatarian dogwood seedlings grown in three soilless growing substrates (Metro-Mix 360, 560, and 902) were irrigated with a nutrient solution at an electrical conductivity (EC) of 1.2 dS·m⁻¹ (control) or saline solution (by adding calculated amount of sodium …

Quantifying Tree Hydration Using Electromagnetic Sensors, Lance V. Stott, Brent Black, Bruce Bugbee

Plants, Soils, and Climate Faculty Publications

An automated method of determining tree water status would enable tree fruit growers, foresters and arborists to reduce water consumption, reduce orchard maintenance costs and improve fruit quality. Automated measurements could also be used to irrigate based on need rather than on fixed schedules. Numerous automated approaches have been studied; all are difficult to implement. Electromagnetic sensors that measure volumetric water content can be inserted in tree trunks to determine relative changes in tree water status. We performed automated measurements of dielectric permittivity using four commercially available electromagnetic sensors in fruit tree trunks over the 2016 growing season. These sensors …

A 100-M-Scale Modeling Study Of A Gale Event On The Lee Side Of A Long Narrow Mountain, Halie Xue, Jian Li, Tingting Qian, Hongping Gu

Plants, Soils, and Climate Faculty Publications

In this study, a gale event that occurred on the lee side of a long narrow mountain was investigated, together with the associated mountain flows, using a realistic-case large-eddy simulation (LES) that is based on the Weather Research and Forecasting Model. The mountain is located on the southeastern Tibetan Plateau, where approximately 58 gales occur annually, mostly in the afternoons during the winter season. Benefitting from realistic topography and high horizontal resolution as fine as 111 m, the LES can replicate features similar to the wind fields observed during the gale period. Investigation of the early morning wind structure over …

Green And Animal Manure Use In Organic Field Crop Systems, Patrick M. Carr, Michel A. Cavigelli, Heather Darby, Kathleen Delate, Jed O. Eberly, Heather K. Fryer, Greta G. Gramig, Joseph R. Heckman, Ellen B. Mallory, Jennifer R. Reeve, Erin M. Silva, David H. Suchoff, Alex L. Woodley

Plants, Soils, and Climate Faculty Publications

Dual‐use cover/green manure (CGM) crops and animal manure are used to supply nitrogen (N) and phosphorus (P) to organically grown field crops. A comprehensive review of previous research was conducted to identify how CGM crops and animal manure have been used to meet N and P needs of organic field crops, and to identify knowledge gaps to direct future research efforts. Results indicate that: (a) CGM crops are used to provide N to subsequent cash crops in rotations; (b) CGM‐supplied N generally can meet field crop needs in warm, humid regions but is insufficient for organic grain crops grown in …

Single-Molecule Real-Time Transcript Sequencing Identified Flowering Regulatory Genes In Crocus Sativus, Xiaodong Qian, Youping Sun, Guifen Zhou, Yumei Yuan, Jing Li, Huilian Huang, Limin Xu, Liqin Li

Plants, Soils, and Climate Faculty Publications

Background: Saffron crocus (Crocus sativus) is a valuable spice with medicinal uses in gynaecopathia and nervous system diseases. Identify flowering regulatory genes plays a vital role in increasing flower numbers, thereby resulting in high saffron yield.

Results: Two full length transcriptome gene sets of flowering and non-flowering saffron crocus were established separately using the single-molecule real-time (SMRT) sequencing method. A total of sixteen SMRT cells generated 22.85 GB data and 75,351 full-length saffron crocus unigenes on the PacBio RS II panel and further obtained 79,028 SSRs, 72,603 lncRNAs and 25,400 alternative splicing (AS) events. Using an Illumina RNA-seq platform, …

Salt Tolerance Of Sego Supremetm Plants, Asmita Paudel, Ji Jhong Chen, Youping Sun, Yuxiang Wang, Richard M. Anderson

Plants, Soils, and Climate Faculty Publications

Sego Supreme^TM is a designated plant breeding and introduction program at the Utah State University Botanical Center and the Center for Water Efficient Landscaping. This plant selection program introduces native and adapted plants to the arid West for aesthetic landscaping and water conservation. The plants are evaluated for characteristics such as color, flowering, ease of propagation, market demand, disease/pest resistance, and drought tolerance. However, salt tolerance has not been considered during the evaluation processes. Four Sego Supreme^TM plants [Aquilegia barnebyi (oil shale columbine), Clematis fruticosa (Mongolian gold clematis), Epilobium septentrionale (northern willowherb), and Tetraneuris acaulis var. arizonica …

Differences In Drought Tolerance Among Gisela® Cherry Rootstocks Determined Using Automated Weighing Lysimeters, Lance V. Stott, Brent Black, Bruce Bugbee

Plants, Soils, and Climate Faculty Publications

The Gisela® series of dwarfing rootstock are widely used because they enable high-density production, but they may be sensitive to drought. Drought tolerance may be associated with root-zone distribution and depth or with physiological adaptation to low water potential. Here we describe a novel technique for determining physiological tolerance to drought when root distribution is held constant. In two matching studies, we continuously measured transpiration of two groups of eight trees using a 16-container automated weighing lysimeter system in a greenhouse. With this system, Gisela® 3, 5, and 12 (G.3, G.5, and G.12) rootstocks were subjected to multiple, controlled drought …

Growth, Gas Exchange, And Mineral Nutrients Of Ornamental Grasses Irrigated With Saline Water, Yuxiang Wang, Youping Sun, Genhua Niu, Chaoyi Deng, Yi Wang, Jorge Gardea-Torresdey

Plants, Soils, and Climate Faculty Publications

Ornamental grasses are commonly used in urban landscapes in Utah and the Intermountain West of the United States. The relative salt tolerance of Eragrostis spectabilis (Pursh) Steud. (purple love grass), Miscanthus sinensis Andersson ‘Gracillimus’ (maiden grass), Panicum virgatum L. ‘Northwind’ (switchgrass), and Schizachyrium scoparium (Michx.) Nash (little bluestem) were evaluated in a greenhouse. Plants were irrigated with a nutrient solution at an electrical conductivity (EC) of 1.2 dS·m^–1 (control), or saline solution at an EC of 5.0 or 10.0 dS·m^–1. At harvest (65 days after the initiation of treatment), P. virgatum and S. scoparium exhibited no foliar …

Quantitative Trait Loci (Qtl) For Forage Traits In Intermediate Wheatgrass When Grown As Spaced-Plants Versus Monoculture And Polyculture Swards, John S. Mortenson, Blair L. Waldron, Steven R. Larson, Kevin B. Jensen, Lee R. Dehann, Michael D. Peel, Paul G. Johnson, J. Earl Creech

Plants, Soils, and Climate Faculty Publications

It has been hypothesized that the genetic control of forage traits, especially biomass, for grass plants growing as spaced-plants versus swards is different. Likewise, the genetic control of compatibility in grass–legume polyculture mixtures is assumed to be different than for forage production in a grass monoculture. However, these hypotheses are largely unvalidated, especially at the DNA level. This study used an intermediate wheatgrass mapping population to examine the effect of three competition environments (spaced-plants, polyculture, and monoculture) on classical quantitative genetic parameters and quantitative trait loci (QTL) identification for biomass, morphology, and forage nutritive value. Moderate to high heritable variation …

Controls And Adaptive Management Of Nitrification In Agricultural Soils, Jeanette M. Norton, Yang Ouyang

Plants, Soils, and Climate Faculty Publications

Agriculture is responsible for over half of the input of reactive nitrogen (N) to terrestrial systems; however improving N availability remains the primary management technique to increase crop yields in most regions. In the majority of agricultural soils, ammonium is rapidly converted to nitrate by nitrification, which increases the mobility of N through the soil matrix, strongly influencing N retention in the system. Decreasing nitrification through management is desirable to decrease N losses and increase N fertilizer use efficiency. We review the controlling factors on the rate and extent of nitrification in agricultural soils from temperate regions including substrate supply, …

Comparing The Salt Tolerance Of Three Landscape Plants Using A Near-Continuous Gradient Dosing System, Ji Jhong Chen, Yuxiang Wang, Asmita Paudel, Youping Sun

Plants, Soils, and Climate Faculty Publications

Screening salinity-tolerant plants is usually time intensive and only applicable to a limited number of salinity levels. A near-continuous gradient dosing (NCGD) system allows researchers to evaluate a large number of plants for salinity tolerance with multiple treatments, more flexibility, and reduced efforts of irrigation. Rose of sharon (Hibiscus syriacus), ninebark (Physocarpus opulifolius), and japanese spirea (Spiraea japonica) were irrigated using an NCGD system with eight electrical conductivity (EC) levels ranging from 0.9 to 6.5 dS·m^–1. At 11 weeks after irrigation was initiated, there were no significant differences among EC levels in …

A Drift-Free Decadal Climate Prediction System For The Community Earth System Model, Yoshimitsu Chikamoto, Axel Timmermann, Matthew J. Widlansky, Shaoqing Zhang, Magdalena A. Balmaseda

Plants, Soils, and Climate Faculty Publications

Performance of a newly developed decadal climate prediction system is examined using the low-resolution Community Earth System Model (CESM). To identify key sources of predictability and determine the role of upper and deeper ocean data assimilation, we first conduct a series of perfect model experiments. These experiments reveal the importance of upper ocean temperature and salinity assimilation in reducing sea surface temperature biases. However, to reduce biases in the sea surface height, data assimilation below 300 m in the ocean is necessary, in particular for high-latitude regions. The perfect model experiments clearly emphasize the key role of combined three-dimensional ocean …