Identification

Title

Comparison of improved AURA tropospheric emission spectrometer COâ‚‚ with HIPPO and SGP aircraft profile measurements

Abstract

Thermal infrared radiances from the Tropospheric Emission Spectrometer (TES) between 10 and 15 Î¼m contain significant carbon dioxide (COâ‚‚) information, however the COâ‚‚ signal must be separated from radiative interference from temperature, surface and cloud parameters, water, and other trace gases. Validation requires data sources spanning the range of TES COâ‚‚ sensitivity, which is approximately 2.5 to 12 km with peak sensitivity at about 5 km and the range of TES observations in latitude (40Â° S to 40Â° N) and time (2005â€“2011). We therefore characterize Tropospheric Emission Spectrometer (TES) COâ‚‚ version 5 biases and errors through comparisons to ocean and land-based aircraft profiles and to the CarbonTracker assimilation system. We compare to ocean profiles from the first three Hiaper Pole-to-Pole Observations (HIPPO) campaigns between 40Â° S and 40Â° N with measurements between the surface and 14 km and find that TES COâ‚‚ estimates capture the seasonal and latitudinal gradients observed by HIPPO COâ‚‚ measurements. Actual errors range from 0.8â€“1.8 ppm, depending on the campaign and pressure level, and are approximately 1.6â€“2 times larger than the predicted errors. The bias of TES versus HIPPO is within 1 ppm for all pressures and datasets; however, several of the sub-tropical TES COâ‚‚ estimates are lower than expected based on the calculated errors. Comparisons to land aircraft profiles from the United States Southern Great Plains (SGP) Atmospheric Radiation Measurement (ARM) between 2005 and 2011 measured from the surface to 5 km to TES COâ‚‚ show good agreement with an overall bias of âˆ’0.3 ppm to 0.1 ppm and standard deviations of 0.8 to 1.0 ppm at different pressure levels. Extending the SGP aircraft profiles above 5 km using AIRS or CONTRAIL measurements improves comparisons with TES. Comparisons to CarbonTracker (version CT2011) show a persistent spatially dependent bias pattern and comparisons to SGP show a time-dependent bias of âˆ’0.2 ppm yrâˆ’1. We also find that the predicted sensitivity of the TES COâ‚‚ estimates is too high, which results from using a multi-step retrieval for COâ‚‚ and temperature. We find that the averaging kernel in the TES product corrected by a pressure-dependent factor accurately reflects the sensitivity of the TES COâ‚‚ product.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.org/ark:/85065/d7736rs1

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

Geographic location

West bounding longitude

East bounding longitude

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2013-03-18T00:00:00Z

Frequency of update

Quality and validity

Lineage

Conformity

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version of format

Constraints related to access and use

Constraint set

Use constraints

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact