Towards an operational Ice Cloud Imager (ICI) retrieval product

Eriksson, Patrick; Rydberg, Bengt; Mattioli, V.; Thoss, Anke; Accadia, Christophe; Klein, Ulf; Buehler, Stefan A.

doi:10.5194/amt-13-53-2020

Cited by 61 publications

(88 citation statements)

References 80 publications

(98 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Consequently, this promotes the use of alternative methods, which are based on retrieval databases and utilize IBA simulations [92]. In fact, such a retrieval database has been suggested for the upcoming ICI operational product [10]. 3.…”

Section: Discussionmentioning

confidence: 99%

“…Moreover, lambertian reflection was assumed. In fact, the way of handling the surface contribution to the simulated brightness temperature is of little concern since, for the frequencies under investigation, it is negligible [10].…”

Section: Radiative Transfer Simulationsmentioning

confidence: 99%

“…Let us consider, for example, the highest frequency channel of ICI; i.e., 664 GHz. For this channel, the noise requirement is 1.6 K [10]. For observations over tropical latitudes that are substantially affected by clouds, there is also a modeling uncertainty of ≈9.5 K, even if a correction is applied (see Table 3).…”

Section: Implications To Future Satellite Instrumentsmentioning

confidence: 99%

“…In contrast to the large wavelengths (frequencies up to ≈190 GHz), sub-millimeter (sub-mm) wavelengths are sensitive to smaller hydrometeors, and thus, can be employed for measuring ice clouds [3,8]. Toward that end, the upcoming Ice Cloud Imager (ICI) instrument, which covers frequencies between 183.31 GHz and 668 GHz, on board the Meteorological Operational Satellite-Second Generation (Metop-SG) [9] operated by the European Organization of Meteorological Satellites (EUMETSAT), is going to fill this gap [10]. The performance of the sub-mm wavelengths in terms of retrieving ice properties has been manifested by airborne and limb sounding instruments; e.g., the International Submillimetre Airborne Radiometer (ISMAR) [11,12], the Compact Scanning Submillimeter-wave Imaging Radiometer (CoSSIR) [13], Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES), and the Odin-Sub-Millimetre Radiometer (Odin-SMR) [14].…”

mentioning

confidence: 99%

See 3 more Smart Citations

Three Dimensional Radiative Effects in Passive Millimeter/Sub-Millimeter All-sky Observations

Barlakas

Eriksson

2020

Remote Sensing

Self Cite

View full text Add to dashboard Cite

This study was conducted to quantify the errors prompted by neglecting three-dimensional (3D) effects, i.e., beam-filling and horizontal photon transport effects, at millimeter/sub-millimeter wavelengths. This paper gives an overview of the 3D effects that impact ice cloud retrievals of both current and proposed (Ice Cloud Imager) satellite instruments operating at frequencies of ≈186.3 and ≈668 GHz. The 3D synthetic scenes were generated from two-dimensional (2D) CloudSat (Cloud Satellite) observations over the tropics and mid-latitudes using a stochastic approach. By means of the Atmospheric Radiative Transfer Simulator (ARTS), three radiative transfer simulations were carried out: one 3D, one independent beam approximation (IBA), and one-dimensional (1D). The comparison between the 3D and IBA simulations revealed a small horizontal photon transport effect, with IBA simulations introducing mostly random errors and a slight overestimation (below 1 K). However, performing 1D radiative transfer simulations results in a significant beam-filling effect that increases primarily with frequency, and secondly, with footprint size. For a sensor footprint size of 15 km, the errors induced by neglecting domain heterogeneities yield root mean square errors of up to ≈4 K and ≈13 K at 186.3 GHz and 668 GHz, respectively. However, an instrument operating at the same frequencies, but with a much smaller footprint size, i.e., 6 km, is subject to smaller uncertainties, with a root mean square error of ≈2 K at 186.3 GHz and ≈7.1 K at 668 GHz. When designing future satellite instruments, this effect of footprint size on modeling uncertainties should be considered in the overall error budget. The smallest possible footprint size should be a priority for future sub-millimeter observations in light of these results.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Radiative Transfer Simulationsmentioning

confidence: 99%

Section: Implications To Future Satellite Instrumentsmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Three Dimensional Radiative Effects in Passive Millimeter/Sub-Millimeter All-sky Observations

Barlakas

Eriksson

2020

Remote Sensing

Self Cite

View full text Add to dashboard Cite

show abstract

“…The arrival of the new spaceborne radar/lidar system EarthCare in 2022 will provide a driving force in both aspects. This will be followed by the Ice Cloud Imager (ICI) in 2023 on EUMETSAT's second generation polar system, giving significantly tighter observational constraints by exploiting sub-millimeter wavelengths and promising a much reduced (50%) uncertainty in IWP retrievals (Eriksson et al, 2020).…”

Section: Sensitivity To Microphysicsmentioning

confidence: 99%

The behavior of high-CAPE summer convection in large-domain large-eddy simulations with ICON

Rybka¹,

Burkhardt²,

Köhler³

et al. 2020

Preprint

View full text Add to dashboard Cite

Abstract. Current state of the art regional numerical weather prediction (NWP) models employ kilometre scale horizontal grid resolutions thereby simulating convection within its grey-zone. Increasing resolution leads to resolving the 3D motion field and has been shown to improve the representation of clouds and precipitation. Using a hectometer-scale model in forecasting mode on a large domain therefore offers a chance to study processes that require the simulation of the 3D motion field at small horizontal scales, such as deep summertime moist convection, a notorious problem in NWP. We use the Icosahedral Nonhydrostatic weather and climate model in large-eddy simulation mode (ICON-LEM) to simulate deep moist convection distinguishing between scattered, large scale dynamically forced and frontal convection. We use different ground and satellite based observational data sets, that supply information on ice water content and path, ice cloud cover and cloud top height on a similar scale as the simulations, in order to evaluate and constrain our model simulations. We find that the timing and geometric extent of the convectively generated cloud shield agrees well with observations while the life time of the convective anvil was, at least in one case, significantly overestimated. Given the large uncertainties of individual ice water path observations, we use a suite of observations in order to better constrain the simulations. ICON-LEM simulates cloud ice water path that lies in-between the different observational data sets but simulations appear to be biased towards a large frozen water path (all frozen hydrometeors). The bias in frozen water path and the longevity of the anvil are little affected by modifications of parameters within the microphysical scheme. In particular one of our convective days appeared to be very sensitive to the initial and boundary conditions which had a large impact on the convective triggering, but little impact on the high frozen water path and long anvil life time bias. Based on this limited set of sensitivity experiments, the evolution of locally forced convection appears to depend more on the uncertainty of the large-scale dynamical state based on data assimilation than of microphysical parameters. Overall, we judge ICON-LEM simulations of deep moist convection to be very close to observations regarding timing, geometrical structure and cloud ice water path of the convective anvil, but other frozen hydrometeors, in particular graupel, are likely overestimated. Therefore, ICON-LEM supplies important information for weather forecasting and forms a good basis for parameterization development based on physical processes or machine learning.

show abstract

Der doppelte Überflieger

Asmus

2024

Physik in unserer Zeit

View full text Add to dashboard Cite

ZusammenfassungFür Wettervorhersagen, Umwelt‐ und Klimaüberwachung werden grundsätzlich zwei unterschiedliche Satellitentypen genutzt: geostationäre und niedrig fliegende Satelliten. Letztere bewegen sich in nur 800 bis 850 km Höhe nahe an den beiden Polen vorbei in einer sonnensynchronen Bahn. Ab 2025 ersetzt die europäische Organisation Eumetsat hierfür die aktuellen Metop‐Satelliten des Eumetsat Polar Systems (EPS) durch die Metop Second Generation (Metop‐SG). Metop‐SG wird aus jeweils zwei Satelliten bestehen. Metop‐SG A hat bildgebende Instrumente für das sichtbare Spektrum, Infrarot und Mikrowellen an Bord. Ebenfalls ein bildgebendes Mikrowelleninstrument sowie Radarinstrumente befinden sich an Bord von Metop‐SG B. Die neuen Satelliten werden wesentlich detailliertere Informationen für Meteorologie, Klimatologie und Umweltüberwachung liefern. Metop‐SG A1 soll Anfang 2025 gestartet werden, Metop‐SG B1 Ende 2025.

show abstract

Towards an operational Ice Cloud Imager (ICI) retrieval product

Cited by 61 publications

References 80 publications

Three Dimensional Radiative Effects in Passive Millimeter/Sub-Millimeter All-sky Observations

Three Dimensional Radiative Effects in Passive Millimeter/Sub-Millimeter All-sky Observations

The behavior of high-CAPE summer convection in large-domain large-eddy simulations with ICON

Der doppelte Überflieger

Contact Info

Product

Resources

About