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At least 37 records · Page 2

Precision Lower Stratospheric Temperature Monitoring with the MSU: Technique, Validation, and Results, 1979-1991

Microwave Sounding Unit channel 4 data from the TIROS-N (Television and Infrared Operational Satellite)-N series of NOAA (National Oceanic and Atmospheric Administration) satellites are intercalibrated to provide a continuous global record of deep-layer averaged lower stratospheric temperatures during 1979-1991. A 13-year record of temperature anomalies is time averaged into pentads and months on a 2.5 deg. grid. The monthly gridpoint anomalies are validated with ten years of radiosonde data during 1979-88. The calibration stability of each satellite's measurements is evaluated during satellite overlap periods, the longest of which reveal no measurable instrumental drift at the level of 0.01 C yr (exp -1). Intercomparisons between NOAA-6 and NOAA- 7 anomalies indicate monthly gridpoint precision of 0.05 C in the tropics to around 0.10 C in the extratropics, and signal-to-noise ratios precision and stability statistics are much better than have been previously reported by other investigators for MSU channel 4. Pentad precision is about 0.10 C in the tropics to around 0.25 C at high latitudes and signal-to- noise ratios generally over 250 in the tropics and high latitudes, but 100-200 in the middle latitudes. Radiosonde comparisons to the monthly gridpoint anomalies have correlations ranging from 0.90 in the tropics (where the interannual variability is smallest) to as high as 0.99 at high-latitude stations. The corresponding standard error of estimate is generally around 0.3 C. A significant difference in decadal trends is found between the satellite and radiosonde systems, with a step change of 0.21 C (sondes cooler) compared to the satellite measurements. Investigations of the possible sources of the discrepancy lead us to suspect that the gradual transition from on-site calibration of sondes with thermometers to factory calibration of sondes around 1982 might have caused a change in the calibration, although this conclusion must be viewed as tentative. The largest globally averaged temperature variations during 1979-91 occur after the El Chichon (1982) and Pinatubo (1991) volcanic eruptions. These warm events are superimposed upon a net downward trend in temperatures during the period. This cooling trend has more of a step function than linear character, with the step occurring during the El Chichon warm event. It is strongest in polar regions and the Northern Hemisphere middle latitudes. These characteristics are qualitatively consistent with radiative adjustments expected to occur with observed ozone depletions.

Spencer, Roy W.↗

Kankakee Water Resources: Monitoring Temperature and Vegetation to Detect River Flow Impediments at Energy Intake Structures

In recent years, unpredictable grassing events have occurred at the Dresden Generating Station, located on the Kankakee River in northern Illinois. Grassing events are characterized by large mats of aquatic vegetation that accumulate downstream, resulting in the clogging of water intake structures and leading to major disruptions in power generation. Currently, employees at the Dresden Generating Station are responsible for reactively responding to each grassing event individually. This project, in partnership with Constellation Nuclear and the United States Geological Survey (USGS), assessed the feasibility of using Earth observations (Landsat 9 OLI-2, Landsat 8 OLI, Sentinel-2 MSI, DOVE PlanetScope, WorldView-3, and GPM IMERG) to detect floating aquatic vegetation within the Kankakee River and identify predictive factors that trigger grassing events, as doing so will provide the Dresden Generating Station the ability to anticipate future grassing events and enhance general hydrologic modeling efforts held by the USGS. The results of this study illustrated that, while aquatic vegetation can be detected by satellites with up to moderate spatial resolution (30 m), temporal resolution is a major limiting factor for tracking movements in floating aquatic vegetation and identifying predictive measures for these events. In addition, correlation results suggest a possible negative relationship between grassing events and river discharge (-0.875 correlation coefficient). In the future, pairing these results with ground control surveys and sensors with higher temporal capabilities would allow our project partners to predict and proactively address future grassing events, ensuring the reliable operation of the Dresden Generating Station.

Marisa Smedsrud↗

Analyzing the Effects of Climate Change on Sea Surface Temperature in Monitoring Coral Reef Health in the Florida Keys Using Sea Surface Temperature Data

This presentation discusses use of 4 kilometer satellite-based sea surface temperature (SST) data to monitor and assess coral reef areas of the Florida Keys. There are growing concerns about the impacts of climate change on coral reef systems throughout the world. Satellite remote sensing technology is being used for monitoring coral reef areas with the goal of understanding the climatic and oceanic changes that can lead to coral bleaching events. Elevated SST is a well-documented cause of coral bleaching events. Some coral monitoring studies have used 50 km data from the Advanced Very High Resolution Radiometer (AVHRR) to study the relationships of sea surface temperature anomalies to bleaching events. In partnership with NOAA's Office of National Marine Sanctuaries and the University of South Florida's Institute for Marine Remote Sensing, this project utilized higher resolution SST data from the Terra's Moderate Resolution Imaging Spectroradiometer (MODIS) and AVHRR. SST data for 2000-2010 was employed to compute sea surface temperature anomalies within the study area. The 4 km SST anomaly products enabled visualization of SST levels for known coral bleaching events from 2000-2010.

Jones, Jason↗

Modeling contamination migration on the Chandra X-Ray Observatory

During its first 5 years of operation, the cold (-60 C) optical blocking filter of the Advanced CCD Imaging Spectrometer (ACIS), on board the Chandra X-ray Observatory, has accumulated a contaminating layer that attenuates the low-energy x rays. To assist in assessing the likelihood of successfully baking off the contaminant, members of the Chandra Team developed contamination-migration simulation software. The simulation follows deposition onto and (temperature-dependent) vaporization from surfaces comprising a geometrical model of the Observatory. A separate thermal analysis, augmented by on-board temperature monitoring, provides temperatures for each surface of the same geometrical model. This paper describes the physical basis for the simulations, the methodologies, and the predicted migration of the contaminant for various bake-out scenarios and assumptions.

O'Dell, Stephen L.↗

High Temperatures Health Monitoring of the Condensed Water Height in Steam Pipe Systems

Ultrasonic probes were designed, fabricated and tested for high temperature health monitoring system. The goal of this work was to develop the health monitoring system that can determine the height level of the condensed water through the pipe wall at high temperature up to 250 deg while accounting for the effects of surface perturbation. Among different ultrasonic probe designs, 2.25 MHz probes with air backed configuration provide satisfactory results in terms of sensitivity, receiving reflections from the target through the pipe wall. A series of tests were performed using the air-backed probes under irregular conditions, such as surface perturbation and surface disturbance at elevated temperature, to qualify the developed ultrasonic system. The results demonstrate that the fabricated air-backed probes combined with advanced signal processing techniques offer the capability of health monitoring of steam pipe under various operating conditions.

High Temperatures (HT)↗

A generalizable machine learning approach to predict land surface temperature

Monitoring of land surface and atmospheric states is highly reliant on satellite data. Traditionally, data products are generated using carefully tuned and validated algorithms for low-earth orbit (LEO) sensors. However, the emerging constellation of geostationary (GEO) sensors contributes global, high temporal resolution observations which can better capture the diurnal variability of key observables like land surface temperature (LST). Using high performance computing and datasets from the NASA Earth Exchange, we exploit co-located, co-temporal observations from LEO and GEO satellites to develop a deep learning-based method for sensor-to-sensor algorithm emulation. Our model is trained on GOES-16 thermal bands to predict MODIS Terra LST and achieves a validation error <2K. Further, application of the model to unseen times of day and a second GEO sensor observing an unseen spatial domain demonstrate the generalization of the deep learning model across space, time and spectra. We anticipate that the synergies between a variety of active orbit configurations can be used to accelerate application of existing algorithms to new datasets.

Kate Marie Duffy↗

Aerial thermal scanner data for monitoring rooftop temperatures

Four Nebraska communities and one South Dakota community were surveyed. Thermal scanner data were converted to a film format and the resultant imagery was successfully employed to monitor rooftop temperatures. The program places emphasis on heat losses resulting from inadequate home insulation, offers CENGAS customers the opportunity to observe a thermogram of their rooftop, and assists homeowners in evaluating insulation needs.

Bjorkland, J.↗

Silicon solar cell monitors high temperature furnace operation

Silicon solar cell, attached to each viewpoint, monitors that incandescent emission from the hot interior of a furnace without interfering with the test assembly or optical pyrometry during the test. This technique can provide continuous indication of hot spots or provide warning of excessive temperatures in cooler regions.

Zellner, G. J.↗

An evaluation of monthly mean MSU and ECMWF global atmospheric temperatures for monitoring climate

The usefulness of global satellite sounding data for monitoring climate was assessed by comparing monthly mean brightness temperature anomalies derived from channel 2 of the microwave sounding units (MSUs) on board NOAA satellites over the past decade with both weighted and pressure-level ECMWF monthly mean temperatures for 96 months from 1982 to 1989. Results show that very good agreement exists between the MSU and the weighted ECMWF temperatures over the period considered, with grid-point correlations exceeding 0.85. Comparisons with individual pressure-level temperatures from ECMWF showed high correlations at 300 mb over most of the globe.

Hurrell, James W.↗

Advanced Signal Processing for High Temperatures Health Monitoring of Condensed Water Height in Steam Pipes

An advanced signal processing methodology is being developed to monitor the height of condensed water thru the wall of a steel pipe while operating at temperatures as high as 250deg. Using existing techniques, previous study indicated that, when the water height is low or there is disturbance in the environment, the predicted water height may not be accurate. In recent years, the use of the autocorrelation and envelope techniques in the signal processing has been demonstrated to be a very useful tool for practical applications. In this paper, various signal processing techniques including the auto correlation, Hilbert transform, and the Shannon Energy Envelope methods were studied and implemented to determine the water height in the steam pipe. The results have shown that the developed method provides a good capability for monitoring the height in the regular conditions. An alternative solution for shallow water or no water conditions based on a developed hybrid method based on Hilbert transform (HT) with a high pass filter and using the optimized windowing technique is suggested. Further development of the reported methods would provide a powerful tool for the identification of the disturbances of water height inside the pipe.

health monitoring↗

A satellite temperature-flux monitor for low perigee applications

An inexpensive, compact, low power, fast response temperature-flux instrument complete with supporting software is described. The device was subjected to extensive ground testing and performed successfully in orbital flight. Highlights of mission results to date are included.

Young, E. W., Jr.↗

Thermal Testing and Integration: Magnetospheric MultiScale (MMS) Observatories with Digital 1-Wire Sensors

Thermocouples require two thin wires to be routed out of the spacecraft to connect to the ground support equipment used to monitor and record the temperature data. This large number of wires that exit the observatory complicates integration and creates an undesirable heat path during testing. These wires exiting the spacecraft need to be characterized as a thermal short that will not exist during flight. To minimize complexity and reduce thermal variables from these ground support equipment (GSE) wires, MMS pursued a hybrid path for temperature monitoring, utilizing thermocouples and digital 1-wire temperature sensors. Digital 1-wire sensors can greatly reduce harness mass, length and complexity as they can be spliced together. For MMS, 350 digital 1-wire sensors were installed on the spacecraft with only 18 wires exiting as opposed to a potential 700 thermocouple wires. Digital 1-wire sensors had not been used in such a large scale at NASAGSFC prior to the MMS mission. During the MMS thermal vacuum testing a lessons learned matrix was formulated that will assist future integration of 1-wires into thermal testing and one day into flight.

Sensors↗

Global atmospheric temperature anomaly monitoring with passive microwave radiometers

The potential of microwave sounding units (MSU) for augmenting the surface-based thermometer record by providing a measurement representing a significant depth of the troposphere is considered. These radiometers measure the thermal emission by molecular oxygen in the atmosphere at different spectral intervals in the oxygen absorption complex near 60 GHz. Brightness temperature variations measured by NOAA-6 and NOAA-7 MSUs during a near-two year period are analyzed and compared with monthly averaged surface air temperature data. It is demonstrated that MSUs, while of limited use for vertical profiling of the atmosphere, provide stable measurements of vertically average atmospheric temperatures, centered at a constant pressure level.

Spencer, Roy W.↗

A simple method for monitoring surface temperatures in plasma treatments

A method consisting of applying temperature markers on the specimen is described for measuring the highest temperature reached by very thin films in situ during deposition. In the first test setup, lowering the input power to 500 W only effected the 177-C marker, while increasing the input power to 1.25 kW effected the 274-C marker. In tests conducted in a dc plasma with markers placed on the uncooled cathode in Ar plasma, the maximum temperatures indicated by the thermocouple matched a change in color of the markers, and no effect of earlier sublimation or decomposition was noted.

Manory, R. R.↗

Monitoring Global Temperatures From Satellites

Report provides evidence that passive microwave radiometry from satellites provides more-precise information on atmospheric temperatures than sparse distribution of thermometers. Accurate temperatures needed for detection of "greenhouse" warming, evaluation of computer models of change in climate, and for understanding important factors in climate system.

Spencer, Roy W.↗

Inference of Global Mean Temperature Trend and Climate Change from MSU and AMSU

Microwave Sounding Unit (MSU) and Advanced MSU (AMSU) radiometers flown on the NOAA operational satellite series are potentially valuable as global temperature monitoring devices. Spencer and Christy pioneered the analysis of mid-tropospheric temperature, given by MSU Channel 2 (Ch 2) at 53.74 GHz, to derive the global temperature trend. Also, in addition to monitoring global temperature, these microwave radiometers have the potential to reveal interannual climate signals in tropics. We have analyzed the data of MSU Ch 2 and AMSU Ch 5 (53.6 GHz) from the NOAA operational satellites for the period 1980 to 2000, utilizing the NOAA calibration procedure. The data are corrected for the satellite orbital drift based on the temporal changes of the on-board warm blackbody temperature. From our analysis, we find that the global temperature increased at a rate of 0.13 +/- 0.05 Kdecade(sup -1) during 1980 to 2000. From an Empirical Orthogonal Function (EOF) analysis of the MSU global data, we find that the mid-tropospheric temperature in middle and high latitudes responds to the ENSO forcing during the Northern Hemisphere Winter in a distinct manner. This mid-latitude response is opposite in phase to that in the tropics. This result is in accord with simulations performed with an ECMWF global spectral model. This study shows a potential use of the satellite observations for climatic change.

Prabhakara, Cuddapah↗