The DOE E3SM Coupled Model Version 1: Overview and Evaluation at Standard Resolution

This work documents the first version of the U.S. Department of Energy (DOE) new Energy Exascale Earth System Model (E3SMv1). We focus on the standard resolution of the fully coupled physical model designed to address DOE mission-relevant water cycle questions. Its components include atmosphere and land (110-km grid spacing), ocean and sea ice (60 km in the midlatitudes and 30 km at the equator and poles), and river transport (55 km) models. This base configuration will also serve as a foundation for additional configurations exploring higher horizontal resolution as well as augmented capabilities in the form of biogeochemistry and cryosphere configurations. The performance of E3SMv1 is evaluated by means of a standard set of Coupled Model Intercomparison Project Phase 6 (CMIP6) Diagnosis, Evaluation, and Characterization of Klima simulations consisting of a long preindustrial control, historical simulations (ensembles of fully coupled and prescribed SSTs) as well as idealized CO2 forcing simulations. The model performs well overall with biases typical of other CMIP-class models, although the simulated Atlantic Meridional Overturning Circulation is weaker than many CMIP-class models. While the E3SMv1 historical ensemble captures the bulk of the observed warming between preindustrial (1850) and present day, the trajectory of the warming diverges from observations in the second half of the twentieth century with a period of delayed warming followed by an excessive warming trend. Using a two-layer energy balance model, we attribute this divergence to the model’s strong aerosol-related effective radiative forcing (ERFari+aci = -1.65 W/m2) and high equilibrium climate sensitivity (ECS = 5.3 K).Plain Language SummaryThe U.S. Department of Energy funded the development of a new state-of-the-art Earth system model for research and applications relevant to its mission. The Energy Exascale Earth System Model version 1 (E3SMv1) consists of five interacting components for the global atmosphere, land surface, ocean, sea ice, and rivers. Three of these components (ocean, sea ice, and river) are new and have not been coupled into an Earth system model previously. The atmosphere and land surface components were created by extending existing components part of the Community Earth System Model, Version 1. E3SMv1’s capabilities are demonstrated by performing a set of standardized simulation experiments described by the Coupled Model Intercomparison Project Phase 6 (CMIP6) Diagnosis, Evaluation, and Characterization of Klima protocol at standard horizontal spatial resolution of approximately 1° latitude and longitude. The model reproduces global and regional climate features well compared to observations. Simulated warming between 1850 and 2015 matches observations, but the model is too cold by about 0.5 °C between 1960 and 1990 and later warms at a rate greater than observed. A thermodynamic analysis of the model’s response to greenhouse gas and aerosol radiative affects may explain the reasons for the discrepancy.Key PointsThis work documents E3SMv1, the first version of the U.S. DOE Energy Exascale Earth System ModelThe performance of E3SMv1 is documented with a set of standard CMIP6 DECK and historical simulations comprising nearly 3,000 yearsE3SMv1 has a high equilibrium climate sensitivity (5.3 K) and strong aerosol-related effective radiative forcing (-1.65 W/m2)Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151288/1/jame20860_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151288/2/jame20860.pd

Evaluation of energy, protein, and selected micronutrient density of homemade complementary foods consumed by children between 6 months and 23 months in food insecure woredas of Wolayita zone, Southern Ethiopia

Motuma Adimasu Abeshu,1,2 Abdulaziz Adish,3 Gulelat D Haki,4 Azeb Lelisa,5 Bekesho Geleta6 1John Snow, Inc, 2Addis Ababa University, Center for Food Science and Nutrition, 3Micronutrient Initiative Africa, Addis Ababa, Ethiopia; 4Department of Food Science and Technology, University of Botswana, Gaborone, Botswana; 5Micronutrient Initiative Ethiopia, 6Ethiopian Public Health Institute, Addis Ababa, Ethiopia Abstract: Complementary feeding should be timely, adequate, and given in a way that is appropriate for the age of the child, applying responsive feeding to fill the gap between what is provided by breastfeeding and the total nutritional requirements of the infant. The purpose of this study was to assess nutrient composition and evaluate adequacy of observed nutrient densities (energy, protein, calcium [Ca], iron [Fe], and zinc [Zn]) in homemade complementary foods for children of age 6–23 months, in comparison to the desired levels in food insecure woredas of the Wolayita zone, Southern Ethiopia. A cross-sectional weighed food record method was used to assess the energy and micronutrient compositions of homemade complementary foods and evaluate adequacy of observed nutrient densities in relation to the desired levels. Multistage sampling was used to locate the children. Observation and measurement of complementary food preparations throughout the day was made. Representative portions from the diets were sampled for further laboratory analysis and to evaluate adequacy of observed nutrient levels. More than 20 different complementary food types (mostly an extension of family foods) prepared from various food items were observed. Dietary diversity of the foods was very poor. The average dietary diversity score was only 2.54, while animal-source foods and vitamin A-rich fruits and vegetables were virtually absent. The energy and protein compositions of the diets, however, were sufficient. Energy density of 0.92 kcal/g, 1.24 kcal/g, and 1.41 kcal/g and protein density of 3.41 g/kcal, 2.18 g/kcal, and 2.48 g/kcal were observed in the diets of 6–8-month, 9–11-month, and 12–23-month age categories, respectively. The diets were poor in micronutrients. The observed nutrient density for Ca and Zn (mg/100 kcal) was significantly lower (P=0.000) than the desired levels. Similarly, the Fe level in the diets for 6–11 month old children was significantly lower than the desired nutrient density levels even when high bioavailability was accounted for. On the contrary, adequate nutrient density in the diets for 12–23 month old ­children was observed even when low bioavailability for Fe was accounted for. The complementary foods were energy dense. Micronutrients densities observed (Ca, Zn, and Fe), however, were very low as they continue to be the “problem nutrients”. Keywords: food insecure, nutrient density, homemade, estimated daily nutrient intak