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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,783 records · Page 99
All sourcesNASA NTRSDOE OSTI
DOE OSTI2013

Atmosphere-Land-Surface Interaction over the Southern Great Plains: Diagnosis of Mechanisms from SGP ARM Data

Work reported included analysis of pentad (5 day) averaged data, proposal of a hypothesis concerning the key role of the Atlantic Multi-decadal Oscillation in 20th century drought and wet periods over the Great Plains, analysis of recurrent super-synoptic evolution of the Great Plains low-level jet, and study of pentad evolution of the 1988 drought and 1993 flood over the Great Plains from a NARR perspective on the atmospheric and terrestrial water balance.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2013

Retrieval of Cloud Properties and Direct Testing of Cloud and Radiation Parameterizations using ARM Observations (Final Report)

This report briefly summaries the work performed at KNMI under DOE Grant DE-FG02-06ER64160 which, in turn was conducted in support of DOE Grant DE-FG02-90ER61071 lead by E. Clothieux of Penn. State U. The specific work at KNMI revolved around the development and application of the EarthCARE simulator to ground-based multi-sensor simulations.

47 OTHER INSTRUMENTATION↗
DOE OSTI2014

ARM Climate Research Facility Quarterly Value-Added Product Report

The purpose of this report is to provide a concise status update for value-added products (VAP) implemented by the Atmospheric Radiation Measurement Climate Research Facility. The report is divided into the following sections: (1) new VAPs for which development has begun, (2) progress on existing VAPs, (3) future VAPs that have been recently approved, (4) other work that leads to a VAP, and (5) top requested VAPs from the archive.

Sivaraman, Chitra↗
DOE OSTI2015

Continuous Evaluation of Fast Processes in Climate Models Using Arm Measurements

Under the support of this grant, we investigated the fast process of interaction of clouds, shallow convection, and boundary layer turbulence and their parameterizations. Main accomplishments involve two things. One is the understanding of the physical mechanisms of low cloud feedbacks; the second is the development and evaluation of convection and cloud parameterizations in climate models.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2015

Solid Phase Characterization of Solids Recovered from Failed Sluicer Arm

The Enclosure to this memo discusses the solid phase characterization of a solid sample that was retrieved from the single-shell Tank 241-C-111 extended reach sluicer #2. This sluicer, removed from riser #3 on September 25, 2014, was found to have approximately 0.4 gallons of solid tank waste adhering to the nozzle area.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

Collaborative Research: Reducing tropical precipitation biases in CESM — Tests of unified parameterizations with ARM observations

The primary objective of this proposal was to quantify and understand biases in the diurnal cycle of precipitation over land and in the frequency of occurrence of light precipitation. The two specific NOAA/ESRL roles were: to use a cloud-resolving model (WRF) to understand the role of microphysics in this bias. In particular we were concerned that the microphysical representations in cloud models might display sensitivity to aerosol loadings; Analyze radar, precipitation, and radiosonde observations from TWP-ICE and compare the spatial distribution and other precipitation characteristics to those generated by WRF; and Facilitate CLUBB development for use in GCMs

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2014

ARM Cloud Aerosol Precipitation Experiment (ACAPEX) Science Plan

The western U.S. receives precipitation predominantly during the cold season when storms approach from the Pacific Ocean. The snowpack that accumulates during winter storms provides about 70-90% of water supply for the region. Understanding and modeling the fundamental processes that govern the large precipitation variability and extremes in the western U.S. is a critical test for the ability of climate models to predict the regional water cycle, including floods and droughts. Two elements of significant importance in predicting precipitation variability in the western U.S. are atmospheric rivers and aerosols. Atmospheric rivers (ARs) are narrow bands of enhanced water vapor associated with the warm sector of extratropical cyclones over the Pacific and Atlantic oceans. Because of the large lower-tropospheric water vapor content, strong atmospheric winds and neutral moist static stability, some ARs can produce heavy precipitation by orographic enhancement during landfall on the U.S. West Coast. While ARs are responsible for a large fraction of heavy precipitation in that region during winter, much of the rest of the orographic precipitation occurs in post-frontal clouds, which are typically quite shallow, with tops just high enough to pass the mountain barrier. Such clouds are inherently quite susceptible to aerosol effects on both warm rain and ice precipitation-forming processes.

Leung, L. R.↗
DOE OSTI2015

Determining Best Estimates and Uncertainties in Cloud Microphysical Parameters from ARM Field Data: Implications for Models, Retrieval Schemes and Aerosol-Cloud-Radiation Interactions

We proposed to analyze in-situ cloud data collected during ARM/ASR field campaigns to create databases of cloud microphysical properties and their uncertainties as needed for the development of improved cloud parameterizations for models and remote sensing retrievals, and for evaluation of model simulations and retrievals. In particular, we proposed to analyze data collected over the Southern Great Plains (SGP) during the Mid-latitude Continental Convective Clouds Experiment (MC3E), the Storm Peak Laboratory Cloud Property Validation Experiment (STORMVEX), the Small Particles in Cirrus (SPARTICUS) Experiment and the Routine AAF Clouds with Low Optical Water Depths (CLOWD) Optical Radiative Observations (RACORO) field campaign, over the North Slope of Alaska during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) and the Mixed-Phase Arctic Cloud Experiment (M-PACE), and over the Tropical Western Pacific (TWP) during The Tropical Warm Pool International Cloud Experiment (TWP-ICE), to meet the following 3 objectives; derive statistical databases of single ice particle properties (aspect ratio AR, dominant habit, mass, projected area) and distributions of ice crystals (size distributions SDs, mass-dimension m-D, area-dimension A-D relations, mass-weighted fall speeds, single-scattering properties, total concentrations N, ice mass contents IWC), complete with uncertainty estimates; assess processes by which aerosols modulate cloud properties in arctic stratus and mid-latitude cumuli, and quantify aerosol’s influence in context of varying meteorological and surface conditions; and determine how ice cloud microphysical, single-scattering and fall-out properties and contributions of small ice crystals to such properties vary according to location, environment, surface, meteorological and aerosol conditions, and develop parameterizations of such effects.In this report we describe the accomplishments that we made on all 3 research objectives.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

Final Technical Report of ASR project entitled “ARM Observations for the Development and Evaluation of Models and Parameterizations of Cloudy Boundary Layers” (DE-SC0000825)

This project aims to elucidate the processes governing boundary layer clouds and improve the treatment of cloud processes in Global Climate Models (GCMs). Specifically, we have made research effort in following areas: (1) Developing novel numerical approach of using multiple scale Weather Research & Forecasting (WRF) model simulations for boundary layer cloud research; (2) Addressing issues of PDF schemes for parameterizing sub-grid scale cloud radiative properties; (3) Investigating the impact of mesoscale cloud organizations on the evolution of boundary layer clouds; (4) Evaluating parameterizations of the cumulus induced vertical transport; (5) Limited area model (LAM) intercomparison study of TWP-ICE convective case; (6) Investigating convective invigoration processes at shallow cumulus cold poll boundaries; and (7) Investigating vertical transport processes in moist convection.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

Advancing cloud lifecycle representation in numerical models using innovative analysis methods that bridge arm observations over a breadth of scales

From its location on the subtropics-midlatitude boundary, the Azores is influenced by both the subtropical high pressure and the midlatitude baroclinic storm regimes, and therefore experiences a wide range of cloud structures, from fair-weather scenes to stratocumulus sheets to deep convective systems. This project combined three types of data sets to study cloud variability in the Azores: a satellite analysis of cloud regimes, a reanalysis characterization of storminess, and a 19-month field campaign that occurred on Graciosa Island. Combined analysis of the three data sets provides a detailed picture of cloud variability and the respective dynamic influences, with emphasis on low clouds that constitute a major uncertainty source in climate model simulations. The satellite cloud regime analysis shows that the Azores cloud distribution is similar to the mean global distribution and can therefore be used to evaluate cloud simulation in global models. Regime analysis of low clouds shows that stratocumulus decks occur under the influence of the Azores high-pressure system, while shallow cumulus clouds are sustained by cold-air outbreaks, as revealed by their preference for post-frontal environments and northwesterly flows. An evaluation of CMIP5 climate model cloud regimes over the Azores shows that all models severely underpredict shallow cumulus clouds, while most models also underpredict the occurrence of stratocumulus cloud decks. It is demonstrated that carefully selected case studies can be related through regime analysis to climatological cloud distributions, and a methodology is suggested utilizing process-resolving model simulations of individual cases to better understand cloud-dynamics interactions and attempt to explain and correct climate model cloud deficiencies.

58 GEOSCIENCES↗
DOE OSTI2016

ARM Support for the Plains Elevated Convection at Night (AS-PECAN) Field Campaign Report

The Plains Elevated Convection at Night (PECAN) field campaign was a large multi-agency/multi-institutional experiment that targeted nighttime convection events in the central plains of the United States in order to better understand a range of processes that lead to the initiation and upscale growth of deep convection. Both weather and climate models struggle to properly represent the timing and intensity of precipitation in the central United States in their simulations. These models must be able to represent the interactions between the nocturnal stable boundary layer (SBL), the nocturnal low-level jet (LLJ), and a reservoir of convectively available potential energy (CAPE) that frequently exists above the SBL. Furthermore, a large fraction of the nocturnal precipitation is due to the organization of mesoscale convective systems (MCSs). In particular, there were four research foci for the PECAN campaign: •The initiation of elevated nocturnal convection focus seeks to elucidate the mesoscaleenvironmental characteristics and processes that lead to convection initiation (CI) and provide baseline data on the early evolution of mesoscale convective clusters. •The dynamics and internal structure and microphysics of nocturnal MCSs focus will investigatethe transition from surface-based to elevated storm structure, the interaction of cold pools generated by MCSs with the nocturnal stable boundary layer, and how the organization and evolution of elevated convection is influenced by the SBL and the vertical profile of wind and stability above the LLJ. •The bores and wave-like disturbances focus seeks to advance knowledge of the initiation of boredisturbances by convection, how the vertical profile of stability and winds modulate bore structure, the role of these disturbances in the initiation, maintenance, and organization of deep convection, and their impact on the LLJ and SBL. •The LLJ focus seeks to understand the processes that influence the spatial and temporal evolutionof the LLJ, how it affects the SBL, and the interaction between the LLJ and atmospheric boundaries in the development of CI.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

Marine ARM GPCI Investigation of Clouds Infrared Sea Surface Temperature Autonomous Radiometer (ISAR) Field Campaign Report

Sea surface temperature (SST) is one of the most appropriate and important climate parameters: a widespread increase is an indicator of global warming and modifications of the geographical distribution of SST are an extremely sensitive indicator of climate change. There is high demand for accurate, reliable, high-spatial-and-temporal-resolution SST measurements for the parameterization of ocean-atmosphere heat, momentum, and gas (SST is therefore critical to understanding the processes controlling the global carbon dioxide budget) fluxes, for detailed diagnostic and process-orientated studies to better understand the behavior of the climate system, as model boundary conditions, for assimilation into climate models, and for the rigorous validation of climate model output. In order to achieve an overall net flux uncertainty < 10 W/m 2 (Bradley and Fairall, 2006), the sea surface (skin) temperature (SSST) must be measured to an error < 0.1 C and a precision of 0.05 C. Anyone experienced in shipboard meteorological measurements will recognize this is a tough specification. These demands require complete confidence in the content, interpretation, accuracy, reliability, and continuity of observational SST data—criteria that can only be fulfilled by the successful implementation of an ongoing data product validation strategy.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

Marine ARM GPCI Investigation of Clouds Sunshine Pyranometer (SPN1) Field Campaign Report

From the SPN1 manual, the SPN1 Sunshine Pyranometer is one sensor with three output channels: 1) total (global) solar radiation, 2) diffuse radiation, and 3) sunshine status. The SPN1 measures short-wave radiation between 400nm and 2700nm in W.m-2. The Direct beam component of solar radiation can be calculated from the Total minus the Diffuse component. The Sunshine status output indicates whether the energy in the direct beam exceeds the World Meteorological Organization (WMO) standard threshold value of 120 W.m-2, using an algorithm based on the Total radiation, and the ratio of Total to Diffuse radiation. The radiation outputs have a cosine-corrected response. The advantages of the SPN1 are 1) It matches the WMO ‘Good Quality’ pyranometer classification. 2) It requires no shadow band or solar tracker. 3) There are no moving parts. 4) It does not need to be adjusted or repositioned to track the sun—a distinct advantage over shade rings or mechanical trackers. 5) It does not need to be oriented towards north. It will work accurately in any orientation as long as it is mounted horizontally. 6) It does not require knowledge of the latitude or longitude, and can be used at any latitude or longitude. 7) It measures sunshine hours as well as Total and Diffuse radiation. 8) The built-in heater allows use in wet or icy conditions.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2019

North Slope of Alaska ARM Facilities Monthly Status Report- January 2019

During the month of January 2019, the TBS crew made progress revamping the equipment to prepare for upcoming 2019 flights. Both winches were upgraded using a SE encore E43 59.3:1 gearbox coupled with a Leeson Permanent magnet motor. This increased the torque capability by approximately 3x and the rotational speed by ~30%. The existing electronics system on one winch was repurposed to power four 3,500 lb ATV winches. These winches will automate the retrieval of the balloons allowing for retrieval during faster winds, and thus increasing potential operating conditions, while also improving crew safety. The ATV winches are expected to be added to the second winch in February. Finally, a new electronics box was designed which will be used to power the new winch motor. The new winch motors are variable speed, meaning they accept 0-180V and the speed correlates to the input voltage. The new electronics boxes will be mounted directly to the winches to allow the winches to be removed from the trailers in case of size/weight operating limitations. The winches will instead be powered directly by 220V generators vs the lead acid battery banks used by the previous systems.

42 ENGINEERING↗