Tropospheric Emission Spectrometer

Tropospheric Emission Spectrometer
Name	Tropospheric Emission Spectrometer
Mission type	Earth observation
Operator	NASA
Manufacturer	Jet Propulsion Laboratory
Launch date	2004-07-04
Launch vehicle	Delta II
Orbit type	Sun-synchronous
Instruments	Fourier transform spectrometer

Tropospheric Emission Spectrometer was an Earth-observing instrument developed by the Jet Propulsion Laboratory and operated by NASA aboard the Aura spacecraft launched during the 2004 spaceflight campaign. It measured infrared emission from the Troposphere to characterize trace gases and aerosols relevant to climate change, air quality, and atmospheric chemistry over regional to global scales. The project involved collaborations with institutions such as California Institute of Technology, NOAA, ESA, and research groups at Harvard University and MIT.

Overview

The instrument was designed to probe tropospheric composition using high-spectral-resolution observations in the infrared, complementing other missions like Aura instruments such as Ozone Monitoring Instrument and Microwave Limb Sounder. Development drew on heritage from missions including Upper Atmosphere Research Satellite, Earth Observing System, and programs at JPL and NASA Goddard Space Flight Center. The project timeline intersected with initiatives led by figures from California Institute of Technology and collaborations with agencies including NOAA and research consortia working on stratospheric ozone and greenhouse gas monitoring.

Instrument Design and Specifications

The payload was a Fourier transform infrared spectrometer using a cryogenically cooled detector assembly developed by teams at Jet Propulsion Laboratory, California Institute of Technology, and subcontractors associated with Lockheed Martin and Raytheon. The design specifications included spectral coverage in mid-infrared bands sensitive to gases such as ozone, carbon monoxide, methane, and nitrous oxide, with resolving power comparable to laboratory-grade instruments used at facilities like NIST. The optical bench and pointing systems incorporated mechanisms and heritage from projects at NASA Goddard Space Flight Center and engineering teams with experience from the Landsat and Terra programs.

Mission and Operations

Launched on a Delta II vehicle as part of the Aura complement, the instrument operated in a sun-synchronous polar orbit coordinated with Terra and Aqua to enable synergistic observations. Routine operations were managed by flight teams at Jet Propulsion Laboratory and mission operations centers at NASA Goddard Space Flight Center with science planning involving investigators from Harvard University, MIT, NOAA, and international partners at ESA laboratories. The mission supported targeted campaigns in regions including North America, Europe, East Asia, and South America coordinated with field facilities such as those operated by NCAR and regional measurement networks.

Data Products and Processing

Data processing pipelines were developed at Jet Propulsion Laboratory and science centers associated with NASA Goddard Space Flight Center to produce Level 1 radiance and Level 2 geophysical retrievals of trace gases, aerosols, and temperature profiles. Algorithms incorporated radiative transfer models and inversion techniques used in studies at Harvard University, Massachusetts Institute of Technology, and University of Cambridge groups working on remote sensing, with quality control practices aligned with standards from NOAA and international consortia including CEOS. Archived datasets were used by investigators at institutions like Columbia University, University of California, Berkeley, and Imperial College London.

Scientific Applications and Findings

Results from the instrument contributed to studies of regional pollution transport observed during events such as transboundary episodes between China and neighboring regions, analyses of seasonal cycles over Amazon Basin deforestation areas, and assessments of emissions inventories used by policy analysts in agencies like EPA and research groups at Princeton University. Publications involving collaborators at Harvard University, Massachusetts Institute of Technology, NOAA, and European Space Agency teams reported improved constraints on global budgets of methane, carbon monoxide, and short-lived climate forcers, influencing modeling efforts at centers such as NCAR and the Hadley Centre. The dataset supported interdisciplinary work involving researchers from Stanford University, University of Oxford, and Potsdam Institute for Climate Impact Research.

Calibration and Validation

Calibration and validation activities engaged laboratory teams at NIST and field campaigns coordinated with networks operated by NOAA, NCAR, and university groups including University of California, Irvine and University of Colorado Boulder. Validation used comparisons with in situ measurements from aircraft campaigns flown by organizations such as NASA research aircraft programs and international campaigns involving European Space Agency assets and university atmospheric chemistry groups. Cross-calibration efforts referenced heritage instruments from programs like Aura and the Earth Observing System to maintain continuity with long-term records.

Related Instruments and Successors

The instrument complemented contemporaneous sensors such as the Ozone Monitoring Instrument, Microwave Limb Sounder, and spectral sounders on Terra and influenced successor concepts implemented in missions led by NASA, ESA, and national agencies in Japan and Canada. Follow-on spectrometers and nadir sounders developed for Sentinel programs, national missions, and proposals supported by centers including Jet Propulsion Laboratory, NASA Goddard Space Flight Center, and university consortia at Massachusetts Institute of Technology and Imperial College London built on its legacy.

Category:Earth observation satellites