The impact of resolution on the adjustment and decadal variability of the Atlantic Meridional Overturning Circulation in a coupled climate model

Variations in the Atlantic Meridional Overturning Circulation (MOC) exert an important influence on climate, particularly on decadal time scales. Simulation of the MOC in coupled climate models is compromised, to a degree that is unknown, by their lack of fidelity in resolving some of the key processes involved. There is an overarching need to increase the resolution and fidelity of climate models, but also to assess how increases in resolution influence the simulation of key phenomena such as the MOC. In this study we investigate the impact of significantly increasing the (ocean and atmosphere) resolution of a coupled climate model on the simulation of MOC variability by comparing high and low resolution versions of the same model. In both versions, decadal variability of the MOC is closely linked to density anomalies that propagate from the Labrador Sea southward along the deep western boundary. We demonstrate that the MOC adjustment proceeds more rapidly in the higher resolution model due the increased speed of western boundary waves. However, the response of the Atlantic Sea Surface Temperatures (SSTs) to MOC variations is relatively robust - in pattern if not in magnitude - across the two resolutions. The MOC also excites a coupled ocean-atmosphere response in the tropical Atlantic in both model versions. In the higher resolution model, but not the lower resolution model, there is evidence of a significant response in the extratropical atmosphere over the North Atlantic 6 years after a maximum in the MOC. In both models there is evidence of a weak negative feedback on deep density anomalies in the Labrador Sea, and hence on the MOC (with a time scale of approximately ten years). Our results highlight the need for further work to understand the decadal variability of the MOC and its simulation in climate models

General Tobacco Policy Survey Questions from the Tobacco Baling Survey

Crop Production/Industries,

Experimental L-band SST satellite communications/surveillance terminal study. Volume 1 - Study summary

Study of design for experimental L band supersonic transport communications/surveillance termina

Tobacco Baling Survey

Crop Production/Industries,

ESD ideas: a simple proposal to improve the contribution of IPCC WGI to the assessment and communication of climate change risks

The purpose of the Intergovernmental Panel on Climate Change (IPCC) is to provide policy-relevant assessments of the scientific evidence about climate change. Policymaking necessarily involves risk assessments, so it is important that IPCC reports are designed accordingly. This paper proposes a specific idea, illustrated with examples, to improve the contribution of IPCC Working Group I to informing climate risk assessments

The Rocketdyne Multifunction Tester. Part 1: Test Method

The Rocketdyne Multifunction Tester is a general purpose test apparatus which utilizes axial and radial magnetic bearings as shaft excitation devices. The tester is modular in design so that different seal and bearing packages can be tested on the same test stand. The tester will be used for rotordynamic coefficient extraction, as well as life and fluid/material compatibility evaluations. Use of a magnetic bearing as a shaft excitation device opens up many possibilities for shaft excitation and rotordynamic coefficient extraction. In addition to describing the basic apparatus, some of the excitation and extraction methods are described. Some of the excitation methods to be discussed include random, aperiodic, harmonic, impulse and chirp

Middle School Parent Opinions of Social Emotional Learning Competencies

The purpose of this study was to explore parent opinions of the teaching of social- emotional learning (SEL) competencies in middle school. Three over-arching questions were examined. First, do parents believe that it is important for SEL competencies to be taught? Next, do sixth grade parents have a different opinion of the teaching of SEL than eight grade parents? And finally, do parents believe that the specific SEL program being utilized at the school is helpful for their children? Quantitative data from the survey indicated that parents were supportive of the teaching of SEL in middle school. Sixth grade parents viewed the competencies of Self- Management, Relationship Skills and Responsible Decision-Making Skills to be more important than eighth grade parents did. Parents believed the program was helpful for their student(s)

Evaluating Relationships between Mercury Concentrations in Air and in Spanish Moss (\u3cem\u3eTillandsia Usneoides\u3c/em\u3e L.)

Mercury is a potent neurotoxin that is transported globally in vapor form. A major source of mercury contamination to soil, water, and biota is atmospheric deposition. Therefore, comprehensive monitoring of atmospheric concentrations is important. Limitations of conventional atmospheric measurement techniques include high cost and lack of temporal or spatial integration. Bioindicators, however, may serve as an integrative tool to add to conventional mercury measurement techniques. Spanish moss (Tillandsia usneoides L.) is a potential bioindicator of atmospheric mercury concentration in the southeastern United States because it is an abundant epiphyte that absorbs and accumulates atmospheric pollutants. A study was conducted in southeastern Georgia and northern Florida to test the hypotheses that 1) Spanish moss absorbs and retains atmospheric mercury in tissue, and 2) atmospheric mercury concentrations differ geographically due to nonpoint emission sources, and the concentration of mercury in Spanish moss tissue reflects these differences. To determine if Spanish moss exhibits uptake and retention of mercury, an experiment was conducted in which I transplanted Spanish moss saturated with mercury vapor in the laboratory to a field site unimpacted by mercury emissions and measured tissue mercury concentration over time. In addition, to determine if mercury concentrations in Spanish moss are reflective of atmospheric concentrations, I conducted two field studies in which the mercury concentrations of both resident and transplanted Spanish moss were compared to atmospheric concentrations at sites with different anthropogenic land use. In all studies, tissue was analyzed for mercury concentration using Inductively-Coupled Plasma Mass Spectrometry. Results suggest Spanish moss absorbs and retains atmospheric mercury, and mercury concentrations in Spanish moss tissue are associated with atmospheric concentrations over both small and large geographic scales. Thus, Spanish moss may serve as a useful measurement tool to add to existing monitoring protocols