SHIRE

Southern Hemisphere polar Infrared Radiation Exp.

15 October 2024 - 28 February 2027

Lead Scientist: dan smale

Observatory: OSC

We plan to deploy an extended-range AERI instrument to Scott Base (78 S, 166 E) in McMurdo Sound, Antarctica to synergize with the NASA PREFIRE satellite mission to examine the closure of atmospheric thermal emission and providing validation for PREFIRE. The AERI will be deployed at Scott Base for one year: October 2025 to October 2026. The two PREFIRE CubeSats were launched successfully in May/June 2024.

SHIRE has three distinct scientific objectives:

1. Provide ancillary data for PREFIRE retrieval algorithm development and validation, specifically through retrieved vertical profiles of temperature and water from the AERI. The time series as retrieved by an AERI will also provide additional contextualization for PREFIRE overpasses, characterizing the observed nature of the atmosphere from a credible instrument. From initial estimates, one PREFIRE CubeSat overpasses Scott Base every two to three days. We expect to capture the variable synoptic weather conditions observed at Scott Base, especially variations in temperature and moisture that may impact the local cryosphere.

2. Investigate the radiative closure of the atmospheric spectrally resolved thermal emission in Antarctica using PREFIRE top-of-the-atmosphere measurements in conjunction with coincident AERI ground-based measurements. Unique characteristics of the Antarctic atmosphere create high uncertainty in the projection of how it will evolve with increasing greenhouse gasses and a warming world. Combined measurements from the AERI and PREFIRE can assess spectral infrared radiative closure under variable atmospheric states and across seasons.

3. Longitudinal study of changes in Antarctica surface radiative forcing due to increasing greenhouse gasses. We will use data from this study and data from previous Antarctic AERI campaigns such as ARM AWARE, 2016 (McMurdo) and SPARCLE, 2001 (South Pole) to quantify the direct change in surface radiative forcing due to changing greenhouse gas concentrations.