PREFIRE

Polar Radiant Energy in the Far InfraRed Experiment

Revealing new aspects of the Arctic climate by measuring the full spectrum of polar radiant energy.

Image courtesy of the Earth Science and Remote Sensing Unit, NASA Johnson Space Center

Overview

PREFIRE makes the first full spectral measurements of Far InfraRed (FIR) radiation, revealing the full spectrum of Arctic radiant energy. It fills a major gap in our knowledge of the Arctic energy budget and the role of FIR radiation in Arctic warming, sea ice loss, ice sheet melt, and sea level rise.

The Arctic is Earth’s thermostat. It regulates the climate by venting excess energy received in the tropics.

Nearly 60% of Arctic emission occurs at wavelengths longer than 15 μm (FIR) that have never been systematically measured.

PREFIRE quantifies spatial and temporal variability in spectral FIR emission and the atmospheric greenhouse effect.

Image courtesy of NASA Visible Earth

Mission

How are we measuring and what will we do with the data?

PREFIRE measures variations in FIR emissivity and greenhouse effect via thermal radiometric sampling at the top of the polar atmosphere. These measurements are integrated with models to understand the role of FIR radiation in Arctic climate.

Baseline Mission

Two 6U CubeSat spacecraft in two different 525 km altitude, near-polar sun-synchronous (97.5° inclination) orbits, each with a heritage miniaturized IR spectrometer, covering the 3-54 μm wavelength region at approximately 0.84 μm spectral sampling, operating for about one seasonal cycle (about a year) with diurnal subsampling.

Threshold Mission

One 6U CubeSat spacecraft (525 km altitude) in near-polar sun-synchronous orbit (97.5° inclination), operating for approximately half a seasonal cycle (about 6 months).

CubeSat Orbit

Two spacecraft in near-polar orbits sample Arctic and Antarctic surfaces and clouds, providing multiple observations of those regions each day.

Image courtesy of NASA Visible Earth

Instrument

TIRS Opto-mechanical design

Thermal IR Spectrometer (TIRS)

Flight-proven hardware and design—TIRS uncooled detector and filter block design maturity are from Mars Climate Sounder and Diviner
Instrument has adequate margins (mass, power, volume, and data rate)
Orbit and mission design flexibility for accommodating different launch opportunities

Technical Specifications

Thermopile array

64 channels x 8 pixels

Spectral sampling

approximately 0.84 μm, from 3-54 μm

Spatial coverage

8 separated pixels, 11.7 km cross-track surface footprint, multiple surface footprint overlaps along-track

Mass

< 3 kg

Data rate

12 kbps

Power

4.5 W

Image courtesy of NASA Visible Earth

Science Team

University of Wisconsin, Department of Atmospheric and Oceanic Sciences, and Space Science and Engineering Center
- Tristan L’Ecuyer, Principal Investigator
- Erin Hokanson Wagner, Data Systems Manager
- Tim Michaels
- Kyle Mattingly
- Nate Miller
- Kevin Hrpcek
- Cam Bertossa
- Natasha Vos
- Hamish Prince
- Carolyn Bean
- Rena Sletten
- Natalie Utomo
- Finn Swanson (summer 2024)
- Meredith Grames (pre-launch and summer 2024)
- James Anheuser (pre-launch)
- Cassidy Johnson (pre-launch)
- Ethan Nelson (pre-launch)
NASA Jet Propulsion Laboratory (JPL)
- Brian Drouin, Deputy Principal Investigator
- Brian Kahn, Co-Investigator
- William Mathews
University of Michigan, Department of Climate and Space Sciences and Engineering
- Xianglei Huang, Co-Investigator
- Aronne Merrelli, Co-Investigator
- Xiuhong Chen
- Zhenning Yang
- Colten Peterson (pre-launch)
- Yan Xie (pre-launch)
Geophysical Fluid Dynamics Laboratory (GFDL), Ocean and Cryosphere Division
- Nicole Schlegel, Co-Investigator
University of Colorado Boulder, Department of Atmospheric and Oceanic Sciences
- Jennifer Kay, Co-Investigator
- Jonah Shaw
- Ash Gilbert
- Leah Bertrand

For more information, contact Erin Hokanson Wagner

Image courtesy of NASA Visible Earth

Latest News

PREFIRE First Light Announcement!

September 3, 2024

NASA has publicly released the first look at PREFIRE mission data, also known as the first light announcement! The PREFIRE science team worked with NASA’s Scientific Visualization Studio to create a first light video. It showcases some of the fascinating infrared details of the Arctic surface and atmosphere that PREFIRE-SAT2 captured in July 2024. The PREFIRE science team is hard at work analyzing the countless measurements that the twin CubeSats are radioing to the ground every day.

2024 PREFIRE Science Team Meeting

August 15, 2024

The 2024 PREFIRE Science Team Meeting was held at the University of Colorado on August 8th and 9th. The PREFIRE team, led by Tristan L'Ecuyer (PI) discussed the status of the PREFIRE CubeSats and instruments, the Science Data Processing System (SDPS), and preliminary data output, as well as the nuances and considerations of this unique dataset. The team also discussed potential validation activities and heard from several external scientists about related projects with the potential for both collaboration and validation.

Second PREFIRE Satellite Launched!

June 5, 2024

Rocket Lab successfully launched the second of two PREFIRE satellites from Mahia, New Zealand at 3:15 pm NZST (3:15 am UTC).

News Archive Image courtesy of NASA Visible Earth

Publications

Peterson, C., X. Chen, Q. Yue, and X. Huang, The spectral dimension of Arctic outgoing longwave radiation and greenhouse efficiency trends from 2003 to 2016, Journal of Geophysical Research: Atmospheres, 124, 8467–8480, 2019, https://doi.org/10.1029/2019JD030428
Kahn, B.H., B.J. Drouin, and T.S. L’Ecuyer, Assessment of sampling sufficiency for low-cost satellite missions: Application to PREFIRE, Journal of Atmospheric and Oceanic Technology, 37, 2283–2298, 2020, https://doi.org/10.1175/JTECH-D-20-0023.1
L'Ecuyer, T.S, B.J. Drouin, J. Anheuser, M. Grames, D. Henderson, X. Huang, B.H. Kahn, J.E. Kay, B.H. Lim, M. Mateling, A. Merelli, N.B. Miller, S. Padmanabhan, C. Peterson, N. Schlegel, M.L. White, and Y. Xie, The Polar Radiant Energy in the Far InfraRed Experiment: A new perspective on polar longwave energy exchanges, Bulletin of the American Meterorological Society, 102, E1431–E1449, 2021, https://doi.org/10.1175/BAMS-D-20-0155.1
Xie, Y., X. Huang, X. Chen, T.S. L’Ecuyer, B.J. Drouin, and J. Wang, Retrieval of surface spectral emissivity in polar regions based on the optimal estimation method. Journal of Geophysical Research: Atmospheres, 127, e2021JD035677, 2022, https://doi.org/10.1029/2021JD035677
Bertossa, C., T.S. L'Ecuyer, A. Merrelli, X. Huang, and X. Chen, A neural network-based cloud mask for PREFIRE and evaluation with simulated observations. Journal of Atmospheric and Oceanic Technology, 40, 377–396, 2023, https://doi.org/10.1175/JTECH-D-22-0023.1
Mattingly, K.S., J.V. Turton, J.D. Wille, B. Noel, X. Fettweis, A.K. Rennermalm, and T.L. Mote, Increasing extreme melt in northeast Greenland linked to foehn winds and atmospheric rivers. Nature Communications, 14, 1743, 2023, https://doi.org/10.1038/s41467-023-37434-8
Miller, N.B., A. Merrelli, T.S. L’Ecuyer, and B.J. Drouin, Simulated clear-sky water vapor and temperature retrievals from PREFIRE measurements. Journal of Atmospheric and Oceanic Technology, 40, 645–659, 2023, https://doi.org/10.1175/JTECH-D-22-0128.1
Shaw, J.K., and J.E. Kay, Processes controlling the seasonally varying emergence of forced Arctic longwave radiation changes, Journal of Climate, 36, 7337–7354, 2023, https://doi.org/10.1175/JCLI-D-23-0020.1
Prince, H.D., and T.S. L'Ecuyer, Observed Energetic Adjustment of the Arctic and Antarctic in a Warming World, Journal of Climate, 37, 2611–2627, 2024, https://doi.org/10.1175/JCLI-D-23-0294.1

Image courtesy of NASA Visible Earth

Dataset

The PREFIRE project will start science operations in late spring of 2024, after which mission data will be publicly accessible some months later through the NASA Atmospheric Science Data Center.

Image courtesy of NASA Visible Earth