TY - JOUR A1 - Nugent, Paul W. A1 - Shaw, Joseph A. A1 - Vollmer, Michael T1 - Colors of thermal pools at Yellowstone National Park JF - Applied Optics Vol. 54 (2015 ) 4, pp. B128-B139 N2 - Abstract The brilliant visible colors of various hot springs and pools in Yellowstone National Park are explained with a combination of scattering from the water and from microbial mats that coat the bottoms of these thermal features. A simple 1D radiative transfer model was used to simulate the colors recorded in visible photographs and the spectrum of light making up these colors. The model includes attenuation in water by absorption and molecular scattering as well as reflection characteristics of the microbial mats and surface reflection of the water. Pool geometries are simulated as simple rough cones scaled to have depths and widths that match published data. Thermal images are also used to record the spatial distribution of water skin temperature. The measurements and simulations confirm that colors observed from shallow-water features arise primarily from the spectral properties of the microbial mat, which is related to the water temperature, while colors observed from deeper water arise primarily from the wavelength-dependent absorption and scattering in the water. Y1 - 2015 U6 - https://doi.org/10.1364/AO.54.00B128 SP - B128 EP - B139 ER - TY - JOUR A1 - Shaw, Joseph A. A1 - Nugent, Paul W. A1 - Vollmer, Michael T1 - Infrared Moon imaging for remote sensing of atmospheric smoke layers JF - Applied Optics 54 (2015) 4, B64-B75 N2 - Abstract Simultaneous visible and long-wave infrared (IR) images of the Moon were used with a simple energy-balance model to study the spatial pattern of lunar surface temperatures. The thermal images were obtained with a radiometrically calibrated, compact, low-cost, commercial IR camera mounted on a small telescope. Differences between the predicted and measured maximum Moon temperatures were used to determine the infrared optical depth (OD), which represents the path-integrated extinction of an elevated layer of wildfire smoke in the atmosphere. The OD values retrieved from the IR Moon images were combined with simultaneous OD measurements from a ground-based, zenith-pointing lidar operating at a wavelength of 532 nm to determine an IR-to-visible OD ratio of 0.50±0.18 for moderately aged wildfire smoke aerosol. © 2014 Optical Society of America Y1 - 2015 U6 - https://doi.org/10.1364/AO.54.000B64 SP - B64 EP - B75 ER - TY - JOUR A1 - Vollmer, Michael A1 - Shaw, Joseph A. A1 - Nugent, Paul W. T1 - Visible and invisible mirages: comparing inferior mirages in the visible and thermal infrared JF - Applied Optics 54 (2015) 4, B76-B84 N2 - Abstract Visible (VIS)-light and thermal infrared (IR) inferior mirages in the 8–14 μm waveband have been observed simultaneously for the takeoff and landing of various airplanes at distances of several kilometers. Similarities as well as differences between the VIS and IR mirages are discussed. © 2014 Optical Society of America Y1 - 2015 U6 - https://doi.org/10.1364/AO.54.000B76 SP - B76 EP - B84 ER - TY - JOUR A1 - Shaw, Joseph A. A1 - Nugent, Paul A1 - Vollmer, Michael T1 - Colors of the Yellowstone thermal pools for teaching optics JF - Proceedings of SPIE 9793, Education and Training in Optics and Photonics: ETOP 2015, 97931S (October 8, 2015) N2 - abstract Nature provides many beautiful optical phenomena that can be used to teach optical principles. Here we describe an interdisciplinary education project based on a simple computer model of the colors observed in the famous thermal pools of Yellowstone National Park in the northwestern United States. The primary wavelength-dependent parameters that determine the widely varying pool colors are the reflectance of the rocks or the microbial mats growing on the rocks beneath the water (the microbial mat color depends on water temperature) and optical absorption and scattering in the water. This paper introduces a teaching module based on a one-dimensional computer model that starts with measured reflectance spectra of the microbial mats and modifies the spectra with depth-dependent absorption and scattering in the water. This module is designed to be incorporated into a graduate course on remote sensing systems, in a section covering the propagation of light through air and water, although it could be adapted to a general university optics course. The module presents the basic 1-D radiative transfer equation relevant to this problem, and allows them to build their own simple model. Students can then simulate the colors that would be observed for different variations of the microbial mat reflectance spectrum, skylight spectrum, and water depth. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only. Y1 - 2015 U6 - https://doi.org/10.1117/12.2223177 ER - TY - JOUR A1 - Vollmer, Michael A1 - Shaw, Joseph A. A1 - Nugent, Paul W. T1 - Heiße Physik im Yellowstone-Park: Wie Farben in Thermalquellen entstehen JF - Physik in unserer Zeit Y1 - 2017 U6 - https://doi.org/10.1002/piuz.201601431 SN - 1521-3943 (online) SN - 0031-9252 (print) VL - 48 IS - 1 SP - 37 EP - 42 ER - TY - CHAP A1 - Vollmer, Michael A1 - Shaw, Joseph A. A1 - Nugent, Paul W. A1 - Harris, Wilson A1 - Gillis, Kendra A1 - Weiss, William A1 - Carpenter, Logan A1 - Carpenter, Amy A1 - Scherrer, Bryan T1 - Photonics in nature: Yellowstone National Park in IR T2 - 14th Conference on Education and Training in Optics and Photonics, ETOP 2017, 2017, Hangzhou, China T3 - Proceedings of SPIE - 104521B Y1 - 2017 U6 - https://doi.org/10.1117/12.2266677 ER - TY - JOUR A1 - Shaw, Joseph A. A1 - Nugent, Paul W. A1 - Harris, Wilson A1 - Vollmer, Michael T1 - Infrared Yellowstone JF - Optics and Photonics News Y1 - 2017 U6 - https://doi.org/10.1364/OPN.28.6.000036 SN - 1541-3721 (Online) SN - 1047-6938 (Print) VL - 28 IS - 6 SP - 36 EP - 43 ER - TY - JOUR A1 - Vollmer, Michael A1 - Shaw, Joseph A. A1 - Nugent, Paul A1 - Harris, Wilson T1 - Heiße Quellen im Wärmebild. Yellowstone‐Park im Infraroten JF - Physik in unserer Zeit Y1 - 2019 U6 - https://doi.org/10.1002/piuz.201901539 VL - 50 IS - 5 SP - 244 EP - 250 PB - Wiley-VCH ER -