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Instrument

CIT-CIMS
California Insitute of Technology Chemical Ionization Mass Spectrometer

The CalTech Chemical Ionization Mass Spectrometer (CIT-CIMS) is an in situ airborne single-mass spectrometer. CIT-CIMS uses CF3O-ion chemistry and compact time-of-flight and triple quadrupole spectrometers to measure specific atmospheric trace gases, including nitric acid, hydrogen peroxide, and sulfur dioxide. It was designed with rapid-scan capabilities, enabling operation at high temporal resolution (10 Hz) and detection across a wide mass range. CIT-CIMS is typically used for airborne observations but can also be employed for ground-based measurements.

Image of the CIT-CIMS during the SOLVE campaign

Image of the CIT-CIMS during the SOLVE campaign

NASA's DC-8 flying laboratory passes Antarctica's tallest peak, Mount Vinson, on Oct. 22, 2012, during a flight over the continent to measure changes in the massive ice sheet and sea ice. Credit: NASA/Michael Studinger (Photography courtesy NASA Images)

Overview

Instrument Details

Measurement Type

Spectrometer/Radiometer

Measurement/Variables

Earth Science > Atmosphere > Atmospheric Chemistry > Carbon And Hydrocarbon Compounds > Hydrogen Cyanide

Earth Science > Atmosphere > Atmospheric Chemistry > Sulfur Compounds > Sulfur Dioxide

Earth Science > Atmosphere > Atmospheric Chemistry > Nitrogen Compounds > Nitric Acid

Earth Science > Atmosphere > Atmospheric Chemistry > Trace Gases/trace Species

Earth Science > Atmosphere > Atmospheric Chemistry

Earth Science > Atmosphere > Air Quality > Volatile Organic Compounds

Earth Science > Atmosphere > Atmospheric Chemistry > Nitrogen Compounds

Earth Science > Atmosphere > Atmospheric Chemistry > Sulfur Compounds

Earth Science > Atmosphere > Air Quality

Earth Science > Atmosphere > Atmospheric Chemistry > Carbon And Hydrocarbon Compounds

Vertical Measurement Regions

Troposphere

Temporal Resolution

10 Hz

Spatial Resolution

Point

Measurement Frequency

N/A

Calibration Details

https://doi.org/10.1021/ac0604235

Online Information

https://airbornescience.nasa.gov/instrument/Chemical_Ionization_Mass_Spectrometer_0

Lead Investigator
Paul Wennberg, John Crounse
Technical Contact
Paul Wennberg
Instrument Maker
Caltech, NCAR
Funding Source
NASA
Overview Publications
Overview Publication
Repository
- Unpublished

Instrument Operation

Platform

Campaigns, where the platform was used with this instrument

Douglas DC-8

45 Campaigns · 182 Instruments

Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys

North America including portions of Canada, Mexico and the Gulf of Mexico

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· 20 Data Products

Student Airborne Research Program

Southern California, Virginia

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Deployment Dates

Start Date	End Date
2025-06-15	2025-08-02
2025-06-22	2025-08-09
2009-07-12	2009-08-13
2010-06-20	2010-07-30
2011-06-19	2011-07-29
2012-06-17	2012-08-10
2013-06-09	2013-08-02
2014-06-15	2014-08-08
2015-06-14	2015-08-07
2016-06-12	2016-08-05
2017-06-18	2017-08-11
2018-06-18	2018-08-10
2019-06-16	2019-08-09
2021-12-03	2021-12-10
2022-06-12	2022-08-05
2023-06-11	2023-08-04
2023-06-18	2023-08-11
2024-06-16	2024-08-09
2024-06-23	2024-08-16

· 25 Data Products

Intercontinental Chemical Transport Experiment - North America

North America, Gulf of Mexico, North Pacific Ocean, North Atlantic Ocean

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· 21 Data Products

Deep Convective Clouds & Chemistry

Northeastern Colorado, West Texas to Central Oklahoma, Northern Alabama

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· 19 Data Products

Arctic Research of the Composition of the Troposphere from Aircraft and Satellites

Alaska, Western Canada, California

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· 27 Data Products

Tropical Composition, Cloud and Climate Coupling

Costa Rica, tropical Eastern Pacific

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· 2 Data Products

Korean United States - Air Quality

South Korean peninsula, including surrounding seas

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· 20 Data Products

Atmospheric Tomography Mission

Western Arctic, South Pacific, Atlantic Ocean, Greenland, Central North America

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· 56 Data Products

Fire Influence on Regional to Global Environments and Air Quality

Northwestern and Southeastern US

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· 27 Data Products

Atmospheric Emissions and Reactions Observed from Megacities to Marine Areas

Urban regions across the western and eastern United States

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· 0 Data Products

Airborne and Satellite Investigation of Asian Air Quality

East and Southeast Asia, Philippines, South Korea, Thailand

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· 8 Data Products

C-130 Hercules

17 Campaigns · 96 Instruments

Intercontinental Chemical Transport Experiment - North America

North America, Gulf of Mexico, North Pacific Ocean, North Atlantic Ocean

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· 21 Data Products

Megacity Initiative: Local and Global Research Observations

Mexico City Metropolitan Area

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· 0 Data Products

Image of ER-2 taking off

Image of ER-2 taking off

NASA Earth Resources-2 Aircraft

63 Campaigns · 109 Instruments

SAGE III Ozone Loss and Validation Experiment

Arctic, Kiruna, Sweden

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· 32 Data Products

Field site of rain gauges and soil moistures sensors from the IFloodS campaign

Field site of rain gauges and soil moistures sensors from the IFloodS campaign

Field Site

76 Campaigns · 175 Instruments

California Research at the Nexus of Air Quality and Climate Change

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· 0 Data Products

Data Products

Filter data products from this instrument by specific campaigns, platforms, or formats.

Campaigns

Platforms

Formats

INTEXA_DC8_AIRCRAFT10.5067/ASDCDAAC/INTEXA/0008

CampaignsIntercontinental Chemical Transport Experiment - North America

PlatformsDouglas DC-8

DC3 In-Situ DC-8 Aircraft Trace Gas Data10.5067/ASDC/SUBORBITAL/DC3_TraceGas_AircraftInSitu_DC8_Data_1

CampaignsDeep Convective Clouds & Chemistry

PlatformsDouglas DC-8

INTEXB_C130_AIRCRAFT10.5067/ASDCDAAC/INTEXB/0011

CampaignsIntercontinental Chemical Transport Experiment - North America

PlatformsC-130 Hercules

FIREX-AQ DC-8 In-Situ Trace Gas Data10.5067/ASDC/FIREXAQ_TraceGas_AircraftInSitu_DC8_Data_1

CampaignsFire Influence on Regional to Global Environments and Air Quality

PlatformsDouglas DC-8

FormatsICARTT

KORUS-AQ DC-8 Aircraft In Situ Trace Gas Data10.5067/ASDC/SUBORBITAL/KORUSAQ_TraceGas_AircraftInSitu_DC8_Data_1

CampaignsKorean United States - Air Quality

PlatformsDouglas DC-8

FormatsICARTT

SEAC4RS DC-8 Aircraft In-Situ Trace Gas Data10.5067/ASDC/SUBORBITAL/SEAC4RS_TraceGas_AircraftInSitu_DC8_Data_1

CampaignsStudies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys

PlatformsDouglas DC-8

SOLVE I ER-2 Aircraft In-situ Trace Gas Data10.5067/ASDC/SUBORBITAL/SOLVE1_TraceGas_AircraftInSitu_ER2_Data_1

CampaignsSAGE III Ozone Loss and Validation Experiment

PlatformsNASA Earth Resources-2 Aircraft

FormatsOther Ames

ARCTAS DC-8 Aircraft In-situ Trace Gas Data10.5067/ASDC/SUBORBITAL/ARCTAS_TraceGas_AircraftInSitu_DC8_Data_1

CampaignsArctic Research of the Composition of the Troposphere from Aircraft and Satellites

PlatformsDouglas DC-8

FormatsICARTT

ASIA-AQ DC-8 In-Situ Trace Gas Data10.5067/SUBORBITAL/ASIA-AQ/DATA001/DC8/TraceGas_AircraftInSitu_1

CampaignsAirborne and Satellite Investigation of Asian Air Quality

PlatformsDouglas DC-8

FormatsICARTT

SARP 2016 Data10.5067/SUBORBITAL/SARP/DATA001/2016

CampaignsStudent Airborne Research Program

PlatformsDouglas DC-8

FormatsICARTT

ATom: In Situ Data from Caltech Chemical Ionization Mass Spectrometer (CIT-CIMS), V210.3334/ORNLDAAC/1927

CampaignsAtmospheric Tomography Mission

PlatformsDouglas DC-8

FormatsICARTT

ATom: Merged Atmospheric Chemistry, Trace Gases, and Aerosols10.3334/ORNLDAAC/1581

CampaignsAtmospheric Tomography Mission

PlatformsDouglas DC-8

FormatsnetCDF

ATom: Merged Atmospheric Chemistry, Trace Gases, and Aerosols, Version 210.3334/ORNLDAAC/1925

CampaignsAtmospheric Tomography Mission

PlatformsDouglas DC-8

FormatsnetCDF