Determination of atmospheric moisture structure and infrared cooling rates from high resolution MAMS radiance data

This program has applied Multispectral Atmospheric Mapping Sensor (MAMS) high resolution data to the problem of monitoring atmospheric quantities of moisture and radiative flux at small spatial scales. MAMS, with 100-m horizontal resolution in its four infrared channels, was developed to study small scale atmospheric moisture and surface thermal variability, especially as related to the development of clouds, precipitation, and severe storms. High-resolution Interferometer Sounder (HIS) data has been used to develop a high spectral resolution retrieval algorithm for producing vertical profiles of atmospheric temperature and moisture. The results of this program are summarized and a list of publications resulting from this contract is presented. Selected publications are attached as an appendix

Meteorological satellite products support for project COHMEX

The first year effort focussed on real-time support and satellite data collection during the field phase of COHMEX. Work efforts following the field phase of COHMEX concentrated on post-processing of the real-time data sets, and generation of enhanced, research-quality satellite data sets for selected COHMEX core days. These satellite-derived data sets will augment the special COHMEX conventional data base with high horizontal and temporal resolution information. The data sets will be examined for their usefulness in delineating important elements in the meteorological environment leading to convective activity. In addition, a limited research effort was conducted using the Cooperative Institute for Meteorological Satellite Studies (CIMSS) 4-d data assimilation system in conjunction with evaluating VISSR Atmospheric Sounder (VAS) and His-resolution Interferometer Sounder (HIS) data. The need to address the characteristics of the data types, and the problems they introduce into 4-d assimilation procedures is evident. The HIS instrument was flown aboard an ER-2 aircraft on several occasions during COHMEX. One of the flights was chosen for further study. Processed VAS soundings and COHMEX radiosonde data were also collected for this day. The case study included an evaluation of the HIS and VAS data and an impact study of the data on the assimilation system analysis

The Space Object Ontology

Achieving space domain awareness requires the identification, characterization, and tracking of space objects. Storing and leveraging associated space object data for purposes such as hostile threat assessment, object identification, and collision prediction and avoidance present further challenges. Space objects are characterized according to a variety of parameters including their identifiers, design specifications, components, subsystems, capabilities, vulnerabilities, origins, missions, orbital elements, patterns of life, processes, operational statuses, and associated persons, organizations, or nations. The Space Object Ontology provides a consensus-based realist framework for formulating such characterizations in a computable fashion. Space object data are aligned with classes and relations in the Space Object Ontology and stored in a dynamically updated Resource Description Framework triple store, which can be queried to support space domain awareness and the needs of spacecraft operators. This paper presents the core of the Space Object Ontology, discusses its advantages over other approaches to space object classification, and demonstrates its ability to combine diverse sets of data from multiple sources within an expandable framework. Finally, we show how the ontology provides benefits for enhancing and maintaining longterm space domain awareness

The impact of high fat diet and chronic intermittent hypoxia on glucose control and cardiorespiratory function

Previous studies have demonstrated carotid body (CB) activity is increased in a high fat diet (HF) induced model of insulin resistance (IR), and carotid sinus nerve resection prevents this and the associated hypertension (HT). The chronic intermittent hypoxia (CIH) of obstructive sleep apnoea also results in HT. We therefore hypothesised the combination of HF induced IR and CIH would result in further increase of CB activity and HT. Effects of HF and CIH on cardiorespiratory parameters, IR, CB activity and sympathetic output were assessed in anaesthetised Wistar rats. HF rats developed obesity, IR and ventricular hypertrophy, with CIH reducing weight gain, but not affecting IR or hypertrophy. Mean arterial blood pressure (MABP) in HF rats tended to be increased by 12±3mmHg, with systolic BP significantly increased. In combination with CIH, MABP tended to be increased by 10±3mmHg, with systolic BP not significantly increased. Treatment groups showed no increased ventilatory drive or sympathetic activity. In conclusion, HF induces obesity, IR and ventricular hypertrophy, however did not result in significant MABP increase. In combination with CIH, obesity is reduced however IR, hypertrophy and MABP do not appear to be affected. Also neither HF diet nor CIH cause increased CB or sympathetic activity

Regulation of platelet production and function by ITIM-containing receptors

Platelets are small highly reactive anucleate cells that circulate in the blood and regulate haemostasis and thrombosis. Understanding the mechanisms regulating platelet function has implications for health and disease. Immunoreceptor tyrosine-based inhibition motif (ITIM)-receptors regulate megakaryocyte and platelet function. The aim of this thesis was to determine the role of ITIM-receptors LAIR-1 and TLT-1 in platelet production and function. LAIR-1 ablation in megakaryocytes results in enhanced SFK activity which is transferred to platelets, rendering them hyper-reactive. LAIR-1 deficient mice exhibit enhanced ferric chloride, but not laser-induced thrombosis in vivo, correlating with GPVI hyper-reactivity observed in vitro. LAIR-1/PECAM-1 double deficient (DKO) mice were mildly thrombocythemic, with platelets hyper-responsive to GPVI activation in vitro. Interestingly, DKO mice lacked the enhanced SFK activity and in vivo thrombosis phenotype of single KO mice. TLT-1 deficient mice exhibit mild thrombocytopenia, with normal aggregation responses to ITAM-receptor and GPCR activation in vitro, and haemostatic response in vivo. Reduced thrombus stability was observed following laser, but not ferric chloride injury in deficient mice, due to marked reduction in α-granule secretion. In addition, TLT-1 was described as a highly sensitive platelet activation marker in vivo, rapidly detected and present throughout core and shell of thrombi

Advancing wildfire fuel mapping and burn severity assessment in Alaskan boreal forest using multi-sensor remote sensing

Thesis (M.S.) University of Alaska Fairbanks, 2021Wildfires in Alaska have been increasing in frequency, size, and intensity putting a strain on communities across the state, especially remote communities lacking firefighting infrastructure to address large scale fire events. Advances in remote sensing techniques and data provide an opportunity to generate high quality map products that can better inform fire managers to allocate resources to areas of most risk and inform scientists how to predict and understand fire behavior. The overarching goal of this thesis is therefore to build insight into methods that can be applied to create highly detailed fire statistic map products in Alaska. To address this overarching goal we tested several methods for generating fire fuel, burn severity, and wildfire hazard maps that were validated using data collected in the field. Applying the Random Forest classifier on Airborne Visible/ Infrared Imaging Spectrometer Next-Generation (AVIRIS-NG) hyperspectral data we were able to produce a fire fuel map with an 81% accuracy. We then tested two supervised machine learning classifiers, post fire standard spectral indices, and differenced spectral indices for their performance in assessing burn severity. We found that supervised machine learning classifiers outperform other algorithms when there is an adequate amount of training data. Using the support vector machine and random forest classifiers we were able to generate burn severity maps with 83% accuracy at the 2019 Shovel Creek Fire. Lastly, we looked for a relationship between burn severity and environmental conditions prevalent during the Shovel Creek and Nugget Creek fires. Overall, these products can be used by fire managers and scientists to assess fire risk, limit the damages caused by wildfires through adequate resource allocation, and provide the guidelines for creating future high quality fire fuel maps.Alaska EPSCoR, the Alaska Space Grant, the University of Alaska Fairbanks College of Natural Science and Mathematics, the University of Alaska Fairbanks Graduate School and Geophysical Society of AlaskaChapter 1: Introduction -- Chapter 2: Improved boreal forest wildfire fuel type mapping in Interior Alaska using AVIRIS-NG hyperspectral data -- Chapter 3: Using remote sensing to map burn severity and assess relationship with environmental factors in the Alaskan boreal forest -- Chapter 4: Conclusion -- Appendix

Sher 25: pulsating but apparently alone

The blue supergiant Sher25 is surrounded by an asymmetric, hourglass-shaped circumstellar nebula, which shows similarities to the triple-ring structure seen around SN1987A. From optical spectroscopy over six consecutive nights, we detect periodic radial velocity variations in the stellar spectrum of Sher25 with a peak-to-peak amplitude of ~12 km/s on a timescale of about 6 days, confirming the tentative detec-tion of similar variations by Hendry et al. From consideration of the amplitude and timescale of the signal, coupled with observed line profile variations, we propose that the physical origin of these variations is related to pulsations in the stellar atmosphere, rejecting the previous hypothesis of a massive, short-period binary companion. The radial velocities of two other blue supergiants with similar bipolar nebulae, SBW1 and HD 168625, were also monitored over the course of six nights, but these did not display any significant radial velocity variations.Comment: 9 pages, 7 figures. Accepted for publication in MNRA