Atmospheric Gas Absorption Knowledge in the Submillimeter: Modeling, Field Measurements, and Uncertainty Quantification

Mattioli, V.; Accadia, Christophe; Prigent, Catherine; Crewell, Susanne; Geer, Alan; Eriksson, Patrick; Fox, Stuart; Pardo, J. R.; Mlawer, E. J.; Cadeddu, Maria; Bremer, M.; Breuck, C. De; Smette, A.; Cimini, Domenico; Turner, Emma; Mech, Mario; Marzano, Frank S.; Brunel, Pascal; Vidot, Jérôme; Bennartz, Ralf; Wehr, T.; Michele, Sabatino Di; John, Viju O.

doi:10.1175/bams-d-19-0074.1

Cited by 9 publications

(4 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The same is true for errors in assumed spectroscopic parameters, used to calculate the absorption due to gases. As ICI will operate in a relatively unexplored wavelength region, considerably spectroscopic uncertainties cannot be ruled out at this point (Mattioli et al, 2019). IS-MAR should also be a useful tool for validation here.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Towards an operational Ice Cloud Imager (ICI) retrieval product

Eriksson

Rydberg²,

Mattioli

et al. 2020

Atmos. Meas. Tech.

Self Cite

View full text Add to dashboard Cite

Abstract. The second generation of the EUMETSAT Polar System (EPS-SG) will include the Ice Cloud Imager (ICI), the first operational sensor covering sub-millimetre wavelengths. Three copies of ICI will be launched that together will give a measurement time series exceeding 20 years. Due to the novelty of ICI, preparing the data processing is especially important and challenging. This paper focuses on activities related to the operational product planned, but also presents basic technical characteristics of the instrument. A retrieval algorithm based on Bayesian Monte Carlo integration has been developed. The main retrieval quantities are ice water path (IWP), mean mass height (Zm) and mean mass diameter (Dm). A novel part of the algorithm is that it fully presents the inversion as a description of the posterior probability distribution. This is preferred for ICI as its retrieval errors do not always follow Gaussian statistics. A state-of-the-art retrieval database is used to test the algorithm and to give an updated estimate of the retrieval performance. The degrees of freedom in measured radiances, and consequently the retrieval precision, vary with cloud situation. According to present simulations, IWP, Zm and Dm can be determined with 90 % confidence at best inside 50 %, 700 m and 50 µm, respectively. The retrieval requires that the data from the 13 channels of ICI are remapped to a common footprint. First estimates of the errors introduced by this remapping are also presented.

show abstract

Section: Discussionmentioning

confidence: 99%

“…Combinations of particle size distribution and habit model included in the test retrieval database. McFarquhar and Heymsfield (1997) is shortened to MH97. Field et al (2007) defined a tropical and a mid-latitude version of their size distribution, and both are used.…”

Section: Test Retrieval Databasementioning

confidence: 99%

Towards an operational Ice Cloud Imager (ICI) retrieval product

Eriksson

Rydberg²,

Mattioli

et al. 2020

Atmos. Meas. Tech.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The same is true for errors in assumed spectroscopic parameters, used to calculate the absorption due to gases. As ICI will operate in a relatively unexplored wavelength region, considerably spectroscopic uncertainties can not be ruled out at this point (Mattioli et al, 2019). Also here ISMAR should be an useful tool for validation.…”

Section: Discussionmentioning

confidence: 99%

Towards an operational Ice Cloud Imager (ICI) retrieval product

Eriksson¹,

Rydberg²,

Mattioli³

et al. 2019

Preprint

Self Cite

View full text Add to dashboard Cite

Abstract. The second generation of the EUMETSAT Polar System (EPS-SG) will include the Ice Cloud Imager (ICI), the first operational sensor covering sub-millimetre wavelengths. Three copies of ICI will be launched that together will give a measurement series exceeding 20 years. Due to the novelty of ICI, preparing the data processing is especially important and challenging. This paper focuses on activities related to the operational product planned, but also presents basic technical characteristics of the instrument. A retrieval algorithm based on Bayesian Monte Carlo integration has been developed. The main retrieval quantities are ice water path (IWP), mean mass height (Zm) and mean mass diameter (Dm). A novel part of the algorithm is to fully present the inversion as a description of the posterior probability distribution. This is to prefer for ICI as its retrieval errors not always follow Gaussian statistics. A state-of-the-art retrieval database is used to test the algorithm and to give an updated estimate of the retrieval performance. The degrees of freedom in measured radiances, and consequently the retrieval precision, vary with cloud situation. According to present simulations, IWP, Zm and Dm can be determined with 90 % confidence at best inside 50 %, 700 m and 50 um, respectively. The retrieval requires that the data from the thirteen channels of ICI are remapped to a common footprint. First estimates of the errors introduced by this remapping are also presented.

show abstract

“…Alternatively, the Millimeter-wave Propagation Model (MPM93) developed by Liebe et al (1993) can be used to simulate the absorption by the gaseous atmosphere. The clear interface structure of PAMTRA gives the possibility to easily include future improvements in gas absorption models, i.e., developments of models in the sub-millimeter wavelength range (Mattioli et al, 2019), as well as the implementation of absorption catalogs (Feist, 2004). This provides the possibility to also account for trace gases, which show abundant but weak absorption features in the microwave frequency range above 200 GHz.…”

Section: Gaseous Absorptionmentioning

confidence: 99%

PAMTRA 1.0: A Passive and Active Microwave radiative TRAnsfer tool for simulating radiometer and radar measurements of the cloudy atmosphere

Mech¹,

Maahn²,

Kneifel³

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

Abstract. Forward models are a key tool to generate synthetic observations given the knowledge of the atmospheric state. In this way they are an integral part of inversion algorithms that aim to retrieve geophysical variables from observations or in data assimilation. Their application for the exploitation of the full information content of remote sensing observations becomes increasingly important when these are used to evaluate the performance of cloud resolving models (CRMs). Herein, CRMs profiles or fields provide the input to the forward model whose simulation results are subsequently compared to the observations. This paper introduces the freely available comprehensive microwave forward model PAMTRA (Passive and Active Microwave TRAnsfer), demonstrates its capabilities to simulate passive and active measurements across the microwave spectral region for up- and downward looking geometries, and illustrates how the forward simulations can be used to evaluate CRMs and to interpret measurements to improve our understanding of cloud processes. PAMTRA is unique as it treats passive and active radiative transfer (RT) in a consistent way with the passive forward model providing up- and down-welling polarized brightness temperatures and radiances for arbitrary observation angles. The active part is capable of simulating the full radar Doppler spectrum and its moments. PAMTRA is designed to be flexible with respect to instrument specifications, interfaces to many different formats of in- and output type, especially CRMs, spanning the range from bin-resolved microphysical output to one- and two-moment schemes, and to in situ measured hydrometeor properties. A specific highlight is the incorporation of the self-similar Rayleigh--Gans Approximation (SSRGA) both for active and passive applications which becomes especially important for the investigation of frozen hydrometeors.

show abstract

Atmospheric Gas Absorption Knowledge in the Submillimeter: Modeling, Field Measurements, and Uncertainty Quantification

Cited by 9 publications

References 7 publications

Towards an operational Ice Cloud Imager (ICI) retrieval product

Towards an operational Ice Cloud Imager (ICI) retrieval product

Towards an operational Ice Cloud Imager (ICI) retrieval product

PAMTRA 1.0: A Passive and Active Microwave radiative TRAnsfer tool for simulating radiometer and radar measurements of the cloudy atmosphere

Contact Info

Product

Resources

About