Angel Otarola

The Active Temperature, Ozone and Moisture Microwave Spectrometer (ATOMMS)

The Active Temperature, Ozone and Moisture Microwave Spectrometer (ATOMMS) is designed to observe Earth’s climate. It extends and overcomes several limitations of the GPS radio occultation capabilities by simultaneously measuring atmospheric bending and absorption at frequencies approximately 10 and 100 times higher than GPS. This paper summarizes several important conceptual improvements to ATOMMS made since OPAC-1 including deriving the hydrostatic upper boundary condition directly from the ATOMMS observations, our much improved understanding of the impact of turbulence and its mitigation, and a new approach to deriving atmospheric profiles in the presence of inhomogeneous liquid water clouds. ATOMMS performance significantly exceeds that of radiometric sounders in terms of precision and vertical resolution and degrades only slightly in the presence of clouds and it does so independently of models. Our aircraft-to-aircraft occultation demonstration of ATOMMS performance will begin in 2009 representing a major step towards an orbiting observing system.

Atmospheric profiling via satellite to satellite occultations near water and ozone absorption lines for weather and climate

Significantly reducing weather and climate prediction uncertainty requires global observations with substantially higher information content than present observations provide. While GPS occultations have provided a major advance, GPS observations of the atmosphere are limited by wavelengths chosen specifically to minimize interaction with the atmosphere. Significantly more information can be obtained via satellite to satellite occultations made at wavelengths chosen specifically to characterize the atmosphere. Here we describe such a system that will probe cm- and mmwavelength water vapor absorption lines called the Active Temperature, Ozone and Moisture Microwave Spectrometer (ATOMMS). Profiling both the speed and absorption of light enables ATOMMS to profile temperature, pressure and humidity simultaneously, which GPS occultations cannot do, as well as profile clouds and turbulence. We summarize the ATOMMS concept and its theoretical performance. We describe field measurements made with a prototype ATOMMS instrument and several important capabilities demonstrated with those ground based measurements including retrieving temporal variations in path-averaged water vapor to 1%, in clear, cloudy and rainy conditions, up to optical depths of 17, remotely sensing turbulence and determining rain rates. We conclude with a vision of a future ATOMMS low Earth orbiting satellite constellation designed to take advantage of synergies between observational needs for weather and climate, ATOMMS unprecedented orbital remote sensing capabilities and recent cubesat technological innovations that enable a constellation of dozens of very small spacecraft to achieve many critical, but as yet unfulfilled, monitoring and forecasting needs.

The Active Temperature, Ozone and Moisture Microwave Spectrometer (ATOMMS), a new global climate sensor

We are developing a new remote sensing system at the University of Arizona called the Active Temperature, Ozone and Moisture Microwave Spectrometer (ATOMMS). ATOMMS combines many of the best features of GPS Radio Occultation (RO) and the Microwave Limb Sounder (MLS) by actively probing cm to sub-mm wavelength atmospheric absorption features via satellite-to-satellite occultation. ATOMMS will provide an unprecedented combination of features for monitoring climate from orbit. With funding from NSF and aircraft time from NASA, we will demonstrate the ATOMMS concept via high altitude aircraft-to-aircraft occultations in 2011. Here we summarize the ATOMMS concept and demonstration project and provide early test results from the instrument indicative of ATOMMS capabilities and performance.