Since 1892, when an aurora was first imaged by martin brendel, a german physicist, useful auroral images have been acquired only when the aurora is in darkness. Rayleigh scattering of sunlight by…

This $2,315,264 federal grant was awarded by NASA to the University of California, Los Angeles (UCLA) on June 1, 2018. The grant aims to address key questions about dayside and sunlit auroral dynamics, which support NASA's strategic goal of understanding the sun and its interactions with Earth.

The grant will enable UCLA to develop the technical capability to image sunlit aurorae from a balloon platform, overcoming challenges with ground-based and space-based observations. This research aligns with NASA's focus on advancing scientific understanding of the magnetosphere and ionosphere. As a prominent public research university and 1862 Land Grant institution, UCLA leverages its extensive research facilities and expertise to execute complex scientific initiatives for federal agencies. The grant does not have a set-aside designation.

Since 1892, when an aurora was first imaged by martin brendel, a german physicist, useful auroral images have been acquired only when the aurora is in darkness. Rayleigh scattering of sunlight by the troposphere and stratosphere during daytime produces broadband emissions that are orders of magnitude brighter than the intensities of UV and visible emissions from even the most intense aurora, thereby rendering the auroral emissions unobservable from ground-based cameras. Aurorae under the sun (hereafter referred to as sunlit aurora) at high magnetic latitudes are observable from space using UV instruments but suffer from poor spatial resolution near the orbit apogee or poor temporal sampling near the orbit perigee, as well as from the UV airglow contamination that has the same wavelength with the UV aurora. As a result, some important questions about dayside and sunlit auroral dynamics remain unanswered or only poorly understood. These questions include: 1) how do the dayside magnetosphere and ionosphere respond to intense solar wind variations in terms of auroral forms and their dynamics? 2) what is the dayside auroral hemispherical asymmetry? 3) are auroras in darkness and under sunlight different or similar in forms and dynamics? Are there unique signatures in sunlit aurora and what causes them? These questions are important because dayside auroral forms (diffuse and discrete morphologies) and their variations are manifestations of the interaction between the solar wind and earth s magnetosphere, and therefore directly support NASA strategic subgoal 2.2: understand the sun and its interactions with earth and the solar system. The solution needed to answer these questions is the ability to image auroral forms and their dynamics in the dayside or sunlit auroral ionosphere. To make a breakthrough in our capability of auroral imaging, this proposal addresses the technical challenge of how to image sunlit auroras from the balloon platform using high-performance near-infrared (NIR) camera. When the auroral measurements from balloons in antarctica are conducted simultaneously with the ground-based ASI and MSP observations in the northern hemisphere, the proposed three science questions can be examined and answered. To achieve the goal of this investigation, six objectives will be accomplished: 1) develop a customized NIR ingaas camera head; 2) develop an onboard data processing unit, iboard, which uses technology developed at JPL along with a customized algorithm to maximize onboard data processing capability, specifically for balloon flights; 3) build a customized large field-of-view optical system that includes a 40 NM band-pass filter centered at 1109 NM to eliminate the OH airglows and sky background, but allow the N2+ meinel (0-0) emissions; 4) integrate the camera system that provides a spatial resolution of~3 KM at ~1000 KM distance at the balloon altitude and test the system from the ground by imaging aurora during twilight when the sky brightness is analogous to that at 35-40 KM altitude in antarctic summer; 5) test the camera from balloon flights to prove the feasibility of imaging sunlit aurora from the balloon and to finalize the most effective flight altitude; 6) observe aurora from a long-duration balloon flight in antarctica, analyze the data, and summarize the science results that address the three science questions. A proof of the project concept in 2006 has confirmed the feasibility of this approach and has identified that the new method is cost effective compared to space-borne imagers, and offers capabilities not currently obtainable from space and the ground. This work is proposed to be conducted as fundamental research.