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Observation And Tracking Of Tropical Cyclones Using Resolution Enhanced Scatterometry, Richard Ryan Halterman
Observation And Tracking Of Tropical Cyclones Using Resolution Enhanced Scatterometry, Richard Ryan Halterman
Theses and Dissertations
The QuikSCAT scatterometer provides global daily coverage of oceanic near-surface vector winds. Recently, algorithms have been developed to enhance the spatial resolution of QuikSCAT winds from 25~km to 2.5~km posting. These ultra-high resolution winds are used, in comparison with standard L2B data product winds, to observe and track tropical cyclones. Resolution enhanced winds are found to provide additional storm structure such as inner core size and structure and the presence of multiple eyewalls compared with standard resolution winds. The 2.5~km winds are also able to observe storms nearer to the shore than 25~km winds. An analysis of circulation center locatability …
Melt Detection In Antarctic Ice Shelves Using Scatterometers And Microwave Radiometers, David G. Long, Lucas B. Kunz
Melt Detection In Antarctic Ice Shelves Using Scatterometers And Microwave Radiometers, David G. Long, Lucas B. Kunz
Faculty Publications
Ku-band dual-polarization radar backscatter measurements from the SeaWinds-on-QuikSCAT scatterometer are used to determine periods of surface freeze and melt in the Antarctic ice shelves. The normalized horizontal-polarization radar backscatter (sigmao) and backscatter polarization ratio are used in maximum-likelihood estimation of the ice state. This method is used to infer the daily ice-surface conditions for 25 study locations located on the Ronne, Ross, Larsen, Amery, Shackleton, and other ice shelves. The temporal and spatial variations of the radar response are observed for various neighborhood sizes surrounding each given location during the study period. Criteria for determining the dates of melt onset …
Melt Detection And Estimation In Greenland Using Tandem Quikscat And Seawinds Scatterometers, Brandon R. Hicks
Melt Detection And Estimation In Greenland Using Tandem Quikscat And Seawinds Scatterometers, Brandon R. Hicks
Theses and Dissertations
Ku-band dual-polarization radar backscatter measurements from the SeaWinds on QuikScat (QuikScat) and SeaWinds on ADEOS-2 (SeaWinds) scatterometers are used to classify the melt state and estimate melt severity in Greenland. Backscatter measurements are organized into high temporal and high spatial resolution images created using the Scatterometer Image Reconstruction (SIR) algorithm and a new temporal data segmentation technique. Melt detection is performed using a layered electromagnetic model combined with a Markov chain model. The new melt detection method allows classification of the snow-pack into three states: melt, refreeze, and frozen. Melt severity and refreeze severity indexes are also developed. The melt …
Microwave Observations Of Daily Antarctic Sea-Ice Edge Expansion And Contraction Rates, David G. Long, Jeffrey R. Allen
Microwave Observations Of Daily Antarctic Sea-Ice Edge Expansion And Contraction Rates, David G. Long, Jeffrey R. Allen
Faculty Publications
Algorithms for estimating sea-ice extent from remotely sensed microwave sensor data can benefit from knowledge of the "a priori" distribution of the daily expansion and contraction of the sea-ice pack. To estimate the probability distribution of daily Antarctic sea-ice extent change, two independent sea-ice datasets are analyzed: sea-ice extent derived from the QuikSCAT scatterometer and ice concentration estimates from the Special Sensor Microwave/Imager. The daily sea-ice advance and retreat is tracked over a four-year period. The distribution of the daily sea-ice advance/retreat from each sensor is similar and is approximately double-exponential. Daily ice-pack statistics are presented.