Subcooled Pool Boiling at Microgravity: Preliminary Ground-Based Experimental Results

A temperature-controlled pool boiling (TCPB) device was developed to perform pool boiling heat transfer studies at both normal gravity on Earth and microgravity in the drop tower Beijing and aboard a Chinese recovery satellite. Two platinum wires of 60 ?m in diameter were simultaneously used as heaters and thermometers. The lengths were 30 mm and 40 mm, respectively. The ends of wires were soldered with copper poles to provide low resistance paths for the electric current. The heater resistance, and thus the heater temperature, was kept constant by a feedback circuit similar to that used in constant-temperature hot-wire anemometry. The fluid was R113 at 0.1 Mpa and subcooled by 30 ?C nominally for all cases. The results of the experiments at normal gravity were presented. Four modes, namely single-phase convection, nucleate boiling, transition two-mode boiling, and film boiling were observed. A few data obtained from several preliminary experiments at microgravity in the drop tower Beijing were also presented. A slight increase of the heat flux was obtained.

Experimental Study on Subcooled Pool Boiling in Microgravity Utilizing

Lateral motion and departure of vapor bubbles in nucleate pool boiling on thin wires in microgravity

A space experiment on bubble behavior and heat transfer in subcooled pool boiling phenomenon has been performed utilizing the temperature-controlled pool boiling (TCPB) device both in normal gravity in the laboratory and in microgravity aboard the 22(nd) Chinese recoverable satellite. The fluid is R113 at 0.1 MPa and subcooled by 26 degrees C nominally. A thin platinum wire of 60 mu m in diameter and 30mm in length is simultaneously used as heater and thermometer. Only the lateral motion and the departure of discrete vapor bubbles in nucleate pool boiling are reported and analyzed in the present paper. A scale analysis on the Marangoni convection surrounding a bubble in the process of subcooled nucleate pool boiling leads to formulas of the characteristic velocity of the lateral motion and its observability. The predictions consist with the experimental observations. Considering the Marangoni effect, a new qualitative model is proposed to reveal the mechanism underlying the bubble departure processes and a quantitative agreement can also be acquired.

Two bifurcation processes for onset of oscillatory thermocapillary convection in a floating half zone

An overview on the onset of thermocapillary oscillatory convection in a floating half zone is provided, and it is a typical subject in the microgravity sciences related to the space materials science, especially the floating zone processing, and also to the microgravity fluid physics. The main interests are focused around the process for onset of oscillatory thermocapillary convection, which is known also as the bifurcation transition from quasi-steady convection to oscillatory convection. The onset of oscillation depends on a set of critical parameters, such as the Marangoni number, Prandtl number, geometrical parameters, and heat transfer parameters. Recent studies show that, there exists the bifurcation transition from steady and axial symmetric convection to the steady and axial non-symmetric convection before the onset of oscillation in cases of small Prandtl number fluids and in cases of larger Prandtl number fluids of fat liquid bridge with small aspect ratio. The transition process is a strong non-linear process because the velocity deviation has the same order of magnitude as that of an average flow after the onset of oscillation, and unsteady 3-D numerical simulation is suitable to do in depth analysis on strong non-linear process, and leads generally to a better comparison with the experimental results.

Ecosystem science capabilities required to support NOAA’s mission in the year 2020

The mission of the National Oceanic and Atmospheric Administration (NOAA) is to understand and predict changes in the Earth’s environment and conserve and manage coastal and marine resources to meet our nation’s economic, social and environmental needs (NOAA, 2004). In meeting its marine stewardship responsibilities, NOAA seeks to ensure the sustainable use of resources and balance competing uses of coastal and marine ecosystems, recognizing both their human and natural components (NOAA, 2004). Authorities for executing these responsibilities come from over 90 separate pieces of Federal legislation, each with unique requirements and responsibilities. Few of these laws explicitly mandate an ecosystem approach to management (EAM) or supporting science. However, resource managers, the science community, and increasingly, the public, are recognizing that significantly greater connectedness among the scientific disciplines is needed to support management and stewardship responsibilities (Browman and Stergiou, 2004; 2005). Neither NOAA nor any other science agency can meet the increasing demand for ecosystem science products addressing each of its mandates individually. Even if it was possible, doing so would not provide the integration necessary to solve the increasingly complex array of management issues. This focus on the integration of science and management responsibilities into an ecosystem view is one of the centerpieces of the U.S. Commission on Ocean Policy’s report (USCOP, 2004), and the Administration’s response to that report in the U.S. Ocean Action Plan (CEQ, 2004). (PDF contains 100 pages)

Science-based restoration monitoring of coastal habitats, Volume One: A framework for monitoring plans under the Estuaries and Clean Waters Act of 2000 (Public Law 160-457)

Executive Summary: The Estuary Restoration Act of 2000 (ERA), Title I of the Estuaries and Clean Waters Act of 2000, was created to promote the restoration of habitats along the coast of the United States (including the US protectorates and the Great Lakes). The NOAA National Centers for Coastal Ocean Science was charged with the development of a guidance manual for monitoring plans under this Act. This guidance manual, titled Science-Based Restoration Monitoring of Coastal Habitats, is written in two volumes. It provides technical assistance, outlines necessary steps, and provides useful tools for the development and implementation of sound scientific monitoring of coastal restoration efforts. In addition, this manual offers a means to detect early warnings that the restoration is on track or not, to gauge how well a restoration site is functioning, to coordinate projects and efforts for consistent and successful restoration, and to evaluate the ecological health of specific coastal habitats both before and after project completion (Galatowitsch et al. 1998). The following habitats have been selected for discussion in this manual: water column, rock bottom, coral reefs, oyster reefs, soft bottom, kelp and other macroalgae, rocky shoreline, soft shoreline, submerged aquatic vegetation, marshes, mangrove swamps, deepwater swamps, and riverine forests. The classification of habitats used in this document is generally based on that of Cowardin et al. (1979) in their Classification of Wetlands and Deepwater Habitats of the United States, as called for in the ERA Estuary Habitat Restoration Strategy. This manual is not intended to be a restoration monitoring “cookbook” that provides templates of monitoring plans for specific habitats. The interdependence of a large number of site-specific factors causes habitat types to vary in physical and biological structure within and between regions and geographic locations (Kusler and Kentula 1990). Monitoring approaches used should be tailored to these differences. However, even with the diversity of habitats that may need to be restored and the extreme geographic range across which these habitats occur, there are consistent principles and approaches that form a common basis for effective monitoring. Volume One, titled A Framework for Monitoring Plans under the Estuaries and Clean Waters Act of 2000, begins with definitions and background information. Topics such as restoration, restoration monitoring, estuaries, and the role of socioeconomics in restoration are discussed. In addition, the habitats selected for discussion in this manual are briefly described. (PDF contains 116 pages)

Science-based restoration monitoring of coastal habitats, Volume Two: Tools for monitoring coastal habitats

Healthy coastal habitats are not only important ecologically; they also support healthy coastal communities and improve the quality of people’s lives. Despite their many benefits and values, coastal habitats have been systematically modified, degraded, and destroyed throughout the United States and its protectorates beginning with European colonization in the 1600’s (Dahl 1990). As a result, many coastal habitats around the United States are in desperate need of restoration. The monitoring of restoration projects, the focus of this document, is necessary to ensure that restoration efforts are successful, to further the science, and to increase the efficiency of future restoration efforts.

Environmental and aesthetic impacts of small docks and piers, workshop report: Developing a science-based decision support tool for small dock management, phase 1: Status of the science

Few issues confronting coastal resource managers are as divisive or difficult to manage as regulating the construction of private recreational docks and piers associated with residential development. State resource managers face a growing population intent on living on or near the coast, coupled with an increasing desire to have immediate access to the water by private docks or piers. (PDF contains 69 pages)

Connectivity: Science, people and policy in the Florida Keys National Marine Sanctuary

Executive Summary: The Connectivity Colloquium evolved from an exhortation by Dan Basta, Director of the National Marine Sanctuary Program, to come together and assess what we know about the condition of our natural resources, identify information gaps and how to fill them, and transform science and management from an emphasis on documentation to a nexus for action. This purpose in some ways reflects the initiation of the Florida Keys National Marine Sanctuary itself, which was designated by an act of the U.S. Congress in 1990 in the aftermath of the 1989 Exxon Valdez oil spill in Alaska and three major ship groundings of the Florida Reef Tract in late 1989. Over the next seven years NOAA worked with federal, state, and local partners to develop a comprehensive management plan for the Sanctuary implemented under a co-trustee partnership between NOAA and the State of Florida. (PDF contains 270 pages; 14Mb)

2002-03 Florida Keys National Marine Sanctuary science report: An ecosystem report card after five years of marine zoning

Executive Summary: Circulation and Exchange of Florida Bay and South Florida Coastal Waters The coastal ecosystem of South Florida is comprised of distinct marine environments. Circulation of surface waters and exchange processes, which respond to both local and regional forcings, interconnect different coastal environments. In addition, re-circulating current systems within the South Florida coastal ecosystem such as the Tortugas Gyre contribute to retention of locally spawned larvae. Variability in salinity, chlorophyll, and light transmittance occurs on a wide range of temporal and spatial scales, in response to both natural forcing, such as seasonal precipitation and evaporation and interannual “El Niño” climate signals, and anthropogenic forcing, such as water management practices in south Florida. The full time series of surface property maps are posted at www.aoml.noaa.gov/sfp. Regional surface circulation patterns, shown by satellite-tracked surface drifters, respond to large-scale forcing such as wind variability and sea level slopes. Recent patterns include slow flow from near the mouth of the Shark River to the Lower Keys, rapid flow from the Tortugas to the shelf of the Carolinas, and flow from the Tortugas around the Tortugas Gyre and out of the Florida Straits. The Southwest Florida Shelf and the Atlantic side of the Florida Keys coastal zone are directly connected by passages between the islands of the Middle and Lower Keys. Movement of water between these regions depends on a combination of local wind-forced currents and gravitydriven transports through the passages, produced by cross-Key sea level differences on time scales of several days to weeks, which arise because of differences in physical characteristics (shape, orientation, and depth) of the shelf on either side of the Keys. A southeastward mean flow transports water from western Florida Bay, which undergoes large variations in water quality, to the reef tract. Adequate sampling of oceanographic events requires both the capability of near real-time recognition of these events, and the flexibility to rapidly stage targeted field sampling. Capacity to respond to events is increasing, as demonstrated by investigations of the 2002 “blackwater” event and a 2003 entrainment of Mississippi River water to the Tortugas. (PDF contains 364 pages.)

Conservation science in NOAA’s National Marine Sanctuaries: description and recent accomplishments

This report describes cases relating to the management of national marine sanctuaries in which certain scientific information was required so managers could make decisions that effectively protected trust resources. The cases presented represent only a fraction of difficult issues that marine sanctuary managers deal with daily. They include, among others, problems related to wildlife disturbance, vessel routing, marine reserve placement, watershed management, oil spill response, and habitat restoration. Scientific approaches to address these problems vary significantly, and include literature surveys, data mining, field studies (monitoring, mapping, observations, and measurement), geospatial and biogeographic analysis, and modeling. In most cases there is also an element of expert consultation and collaboration among multiple partners, agencies with resource protection responsibilities, and other users and stakeholders. The resulting management responses may involve direct intervention (e.g., for spill response or habitat restoration issues), proposal of boundary alternatives for marine sanctuaries or reserves, changes in agency policy or regulations, making recommendations to other agencies with resource protection responsibilities, proposing changes to international or domestic shipping rules, or development of new education or outreach programs. (PDF contains 37 pages.)

Enabling high-throughput data transfers for climate and earth observation science

Supporting presentation slides from the Janet network end to end performance initiative