Ice injected into the tropopause by deep convection – Part 2: Over the Maritime Continent

Abstract. The amount of ice injected into the tropical tropopause layer has a strong radiative impact on climate. A companion paper (Part 1) used the amplitude of the diurnal cycle of ice water content (IWC) as an estimate of ice injection by deep convection, showed that the Maritime Continent (MariCont) region provides the largest injection to the upper troposphere (UT; 146 hPa) and to the tropopause level (TL; 100 hPa). This study focuses on the MariCont region and extends that approach to assess the processes, the areas and the diurnal amount and duration of ice injected over islands and over seas during the austral convective season. The model presented in the companion paper is again used to estimate the amount of ice injected (ΔIWC) by combining ice water content (IWC) measured twice a day by the Microwave Limb Sounder (MLS; Version 4.2) from 2004 to 2017 and precipitation (Prec) measurements from the Tropical Rainfall Measurement Mission (TRMM; Version 007) binned at high temporal resolution (1 h). The horizontal distribution of ΔIWC estimated from Prec (ΔIWCPrec) is presented at 2∘×2∘ horizontal resolution over the MariCont. ΔIWC is also evaluated by using the number of lightning events (Flash) from the TRMM-LIS instrument (Lightning Imaging Sensor, from 2004 to 2015 at 1 h and 0.25∘ × 0.25∘ resolution). ΔIWCPrec and ΔIWC estimated from Flash (ΔIWCFlash) are compared to ΔIWC estimated from the ERA5 reanalyses (ΔIWCERA5) with the vertical resolution degraded to that of MLS observations (ΔIWCERA5). Our study shows that the diurnal cycles of Prec and Flash are consistent with each other in phase over land but different over offshore and coastal areas of the MariCont. The observational ΔIWC range between ΔIWCPrec and ΔIWCFlash, interpreted as the uncertainty of our model in estimating the amount of ice injected, is smaller over land (where ΔIWCPrec and ΔIWCFlash agree to within 22 %) than over ocean (where differences are up to 71 %) in the UT and TL. The impact of the MLS vertical resolution on the estimation of ΔIWC is greater in the TL (difference between ΔIWCERA5 and 〈ΔIWCERA5〉 of 32 % to 139 %, depending on the study zone) than in the UT (difference of 9 % to 33 %). Considering all the methods, in the UT, estimates of ΔIWC span 4.2 to 10.0 mg m−3 over land and 0.4 to 4.4 mg m−3 over sea, and in the TL estimates of ΔIWC span 0.5 to 3.9 mg m−3 over land and 0.1 to 0.7 mg m−3 over sea. Finally, based on IWC from MLS and ERA5, Prec and Flash, this study highlights that (1) at both levels, ΔIWC estimated over land can be more than twice that estimated over sea and (2) small islands with high topography present the largest ΔIWC (e.g., island of Java).

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Ice injected into the tropopause by deep convection – Part 2: Over the Maritime Continent

10.5194/acp-2019-800 ◽

2019 ◽

Author(s):

Iris-Amata Dion ◽

Cyrille Dallet ◽

Philippe Ricaud ◽

Fabien Carminati ◽

Peter Haynes ◽

...

Keyword(s):

Deep Convection ◽

Companion Paper ◽

Horizontal Resolution ◽

Horizontal Distribution ◽

High Temporal Resolution ◽

Vertical Resolution ◽

Maritime Continent ◽

Diurnal Cycles ◽

Tropical Tropopause ◽

Study Zone

Abstract. The amount of ice injected up to the tropical tropopause layer has a strong radiative impact on climate. In the tropics, the Maritime Continent (MariCont) region presents the largest injection of ice by deep convection into the upper troposphere (UT) and tropopause level (TL) (from results presented in the companion paper Part 1). This study focuses on the MariCont region and aims to assess the processes, the areas and the diurnal amount and duration of ice injected by deep convection over islands and over seas using a 2° × 2° horizontal resolution during the austral convective season of December, January and February. The model presented in the companion paper is used to estimate the amount of ice injected (∆IWC) up to the TL by combining ice water content (IWC) measured twice a day in tropical UT and TL by the Microwave Limb Sounder (MLS; Version 4.2), from 2004 to 2017, and precipitation (Prec) measurement from the Tropical Rainfall Measurement Mission (TRMM; Version 007) at high temporal resolution (1 hour). The horizontal distribution of ∆IWC estimated from Prec (∆IWCPrec) is presented at 2° × 2° horizontal resolution over the MariCont. ∆IWC is also evaluated by using the number of lightnings (Flash) from the TRMM-LIS instrument (Lightning Imaging Sensor, from 2004 to 2015 at 1-h and 0.25° × 0.25° resolutions). ∆IWCPrec and ∆IWC estimated from Flash (∆IWCFlash) are compared to ∆IWC estimated from the ERA5 reanalyses (∆IWCERA5) degrading the vertical resolution to that of MLS observations (). Our study shows that, while the diurnal cycles of Prec and Flash are consistent to each other in timing and phase over lands and different over offshore and coastal areas of the MariCont, the observational ∆IWC range between ∆IWCPrec and ∆IWCFlash is small (to within 4–20 % over land and to within 6–50 % over ocean) in the UT and TL. The reanalysis ∆IWC range between ∆IWCERA5 and has been also found to be small in the UT (22–32 %) but large in the TL (68–71 %), highlighting the stronger impact of the vertical resolution on the TL than in the UT. Combining observational and reanalysis ∆IWC ranges, the total ∆IWC range is estimated in the UT between 4.17 and 9.97 mg m−3 (20 % of variability per study zone) over land and between 0.35 and 4.37 mg m−3 (30 % of variability per study zone) over sea, and, in the TL, between 0.63 and 3.65 mg m−3 (70 % of variability per study zone) over land and between 0.04 and 0.74 mg m−3 (80 % of variability per study zone) over sea. Finally, from IWCERA5, Prec and Flash, this study highlights (1) ∆IWC over land has been found larger than ∆IWC over sea, and (2) the Java Island is the area of the largest ∆IWC in the UT (7.89–8.72 mg m−3 daily mean).

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A Prototype Method for Diagnosing High Ice Water Content Probability Using Satellite Imager Data

10.5194/amt-2017-367 ◽

2017 ◽

Cited By ~ 1

Author(s):

Christopher R. Yost ◽

Kristopher M. Bedka ◽

Patrick Minnis ◽

Louis Nguyen ◽

J. Walter Strapp ◽

...

Keyword(s):

Water Content ◽

Deep Convection ◽

Engine Performance ◽

Aircraft Engine ◽

Radar Data ◽

High Mass ◽

Cloud Optical Depth ◽

Geo Satellite ◽

Ice Water Content ◽

Ice Water

Abstract. Recent studies have found that flight through deep convective storms and ingestion of high mass concentrations of ice crystals, also known as high ice water content (HIWC), into aircraft engines can adversely impact aircraft engine performance. These aircraft engine icing events caused by HIWC have been documented during flight in weak reflectivity regions near convective updraft regions that do not appear threatening in onboard weather radar data. Three airborne field campaigns were conducted in 2014 and 2015 to better understand how HIWC is distributed in deep convection, both as a function of altitude and proximity to convective updraft regions, and to facilitate development of new methods for detecting HIWC conditions, in addition to many other research and regulatory goals. This paper describes a prototype method for detecting HIWC conditions using geostationary (GEO) satellite imager data coupled with in-situ total water content (TWC) observations collected during the flight campaigns. Three satellite-derived parameters were determined to be most useful for determining HIWC probability: 1) the horizontal proximity of the aircraft to the nearest overshooting convective updraft or textured anvil cloud, 2) tropopause-relative infrared brightness temperature, and 3) daytime-only cloud optical depth. Statistical fits between collocated TWC and GEO satellite parameters were used to determine the membership functions for the fuzzy logic derivation of HIWC probability. The products were demonstrated using data from several campaign flights and validated using a subset of the satellite-aircraft collocation database. The daytime HIWC probability was found to agree quite well with TWC time trends and identified extreme TWC events with high probability. Discrimination of HIWC was more challenging at night with IR-only information. The products show the greatest capability for discriminating TWC ≥ 0.5 g m−3. Product validation remains challenging due to vertical TWC uncertainties and the typically coarse spatio-temporal resolution of the GEO data.

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High ice water content at low radar reflectivity near deep convection – Part 2: Evaluation of microphysical pathways in updraft parcel simulations

Atmospheric Chemistry and Physics ◽

10.5194/acp-15-11729-2015 ◽

2015 ◽

Vol 15 (20) ◽

pp. 11729-11751 ◽

Cited By ~ 17

Author(s):

A. S. Ackerman ◽

A. M. Fridlind ◽

A. Grandin ◽

F. Dezitter ◽

M. Weber ◽

...

Keyword(s):

Water Vapor ◽

Water Content ◽

Deep Convection ◽

Radar Reflectivity ◽

Doppler Velocity ◽

Diffusional Growth ◽

Ice Particles ◽

Ice Water Content ◽

Water Drops ◽

Ice Water

Abstract. The aeronautics industry has established that a threat to aircraft is posed by atmospheric conditions of substantial ice water content (IWC) where equivalent radar reflectivity (Ze) does not exceed 20–30 dBZ and supercooled water is not present; these conditions are encountered almost exclusively in the vicinity of deep convection. Part 1 (Fridlind et al., 2015) of this two-part study presents in situ measurements of such conditions sampled by Airbus in three tropical regions, commonly near 11 km and −43 °C, and concludes that the measured ice particle size distributions are broadly consistent with past literature with profiling radar measurements of Ze and mean Doppler velocity obtained within monsoonal deep convection in one of the regions sampled. In all three regions, the Airbus measurements generally indicate variable IWC that often exceeds 2 g m-3 with relatively uniform mass median area-equivalent diameter (MMDeq) of 200–300 μm. Here we use a parcel model with size-resolved microphysics to investigate microphysical pathways that could lead to such conditions. Our simulations indicate that homogeneous freezing of water drops produces a much smaller ice MMDeq than observed, and occurs only in the absence of hydrometeor gravitational collection for the conditions considered. Development of a mass mode of ice aloft that overlaps with the measurements requires a substantial source of small ice particles at temperatures of about −10 °C or warmer, which subsequently grow from water vapor. One conceivable source in our simulation framework is Hallett–Mossop ice production; another is abundant concentrations of heterogeneous ice freezing nuclei acting together with copious shattering of water drops upon freezing. Regardless of the production mechanism, the dominant mass modal diameter of vapor-grown ice is reduced as the ice-multiplication source strength increases and as competition for water vapor increases. Both mass and modal diameter are reduced by entrainment and by increasing aerosol concentrations. Weaker updrafts lead to greater mass and larger modal diameters of vapor-grown ice, the opposite of expectations regarding lofting of larger ice particles in stronger updrafts. While stronger updrafts do loft more dense ice particles produced primarily by raindrop freezing, we find that weaker updrafts allow the warm rain process to reduce competition for diffusional growth of the less dense ice expected to persist in convective outflow.

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Ice Microphysical Properties near the Tops of Deep Convective Cores Implied by the GPM Dual-Frequency Radar Observations

Journal of the Atmospheric Sciences ◽

10.1175/jas-d-18-0243.1 ◽

2019 ◽

Vol 76 (9) ◽

pp. 2899-2917 ◽

Cited By ~ 2

Author(s):

Xiang Ni ◽

Chuntao Liu ◽

Edward Zipser

Keyword(s):

Particle Size ◽

Water Content ◽

Deep Convection ◽

Radar Reflectivity ◽

Lookup Table ◽

Dual Frequency ◽

Ka Band ◽

Microphysical Properties ◽

Ice Water Content ◽

Ice Water

Abstract Using three years of observations from the Dual-Frequency Precipitation Radar (DPR) aboard the Global Precipitation Measurement (GPM) Core Observatory, properties of the cores of deep convection are examined. First, deep convective systems are selected, defined as GPM precipitation features with maximum 20-dBZ echo-top heights above 10 km. The cores of deep convection are described by the profiles of Ku- and Ka-band radar reflectivity at the location of the highest echo top in each deep convective system. Then the dual-frequency ratio (DFR) profile is derived by subtracting Ka-band from Ku-band radar reflectivity. It is found that values of DFR are larger over land than over ocean in general near the top of the convection, which is consistent with larger ice particles in stronger updrafts in continental convection. The magnitude of DFR at 12 km is positively correlated with the convection intensity indicated by 20- and 30-dBZ echo tops. The microphysical properties including volume-weighted mean diameter, ice water content, and total ice particle number concentration are derived using a simple lookup table approach. Under the same particle size distribution assumption, the cores of deep convection over land have larger ice particle size, higher ice water content, and lower particle concentration than those over ocean at levels above 10 km, but with some distinct regional variations.

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A ubiquitous ice size bias in simulations of tropical deep convection

10.5194/acp-2017-99 ◽

2017 ◽

Author(s):

McKenna W. Stanford ◽

Adam Varble ◽

Ed Zipser ◽

J. Walter Strapp ◽

Delphine Leroy ◽

...

Keyword(s):

Water Content ◽

Deep Convection ◽

Particle Sizes ◽

Size Distributions ◽

Particle Properties ◽

Ice Water Content ◽

High Bias ◽

Microphysical Processes ◽

Bin Microphysics ◽

Ice Water

Abstract. The High Altitude Ice Crystals – High Ice Water Content (HAIC-HIWC) joint field campaign produced aircraft retrievals of total condensed water content (TWC), hydrometeor particle size distributions (PSDs), and vertical velocity (w) in high ice water content regions of mature and decaying tropical mesoscale convective systems (MCSs). The resulting dataset is used here to explore causes of the commonly documented high bias in radar reflectivity within cloud-resolving simulations of deep convection. This bias has been linked to overly strong simulated convective updrafts lofting excessive condensate mass but is also modulated by parameterizations of hydrometeor size distributions, single particle properties, species separation, and microphysical processes. Observations are compared with three Weather Research and Forecasting model simulations of an observed MCS using differing microphysics while controlling for w, TWC, and temperature. Two bulk microphysics schemes (Thompson and Morrison) and one bin microphysics scheme (Fast Spectral Bin Microphysics) are compared. For temperatures between −10 °C and −40 °C and TWC > 1 g m−3 inside updrafts, all microphysics schemes produce median mass diameters (MMDs) that are generally larger than observed, and the precipitating ice species that controls this size bias varies by scheme, temperature, and w. Despite a much greater number of samples, all simulations fail to reproduce observed high TWC conditions (> 2 g m−3) between −20 °C and −40 °C in which only a small fraction of condensate mass is found in relatively large particle sizes greater than 1 mm in diameter. Although more mass is distributed to relatively large particle sizes relative to observed across all schemes when controlling for temperature, w, and TWC, differences with observations for a given particle size vary greatly between schemes. As a result, this bias is hypothesized to partly result from errors in parameterized hydrometeor PSD and single particle properties, but because it is present in all schemes, it may also partly result from errors in parameterized microphysical processes present in all schemes. Because of these ubiquitous ice size biases, microphysical parameterizations inherently produce a high bias in convective reflectivity for a wide range of temperatures, vertical velocities, and TWCs.

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Impact of a simple parameterization of convective gravity-wave drag in a stratosphere-troposphere general circulation model and its sensitivity to vertical resolution

Annales Geophysicae ◽

10.1007/s00585-998-0238-z ◽

1998 ◽

Vol 16 (2) ◽

pp. 238-249 ◽

Cited By ~ 15

Author(s):

C. Bossuet ◽

M. Déqué ◽

D. Cariolle

Keyword(s):

General Circulation ◽

Climate Model ◽

Positive Impact ◽

Deep Convection ◽

Circulation Model ◽

Wave Drag ◽

Horizontal Resolution ◽

Vertical Resolution ◽

Mean Flow ◽

The Impact

Abstract. Systematic westerly biases in the southern hemisphere wintertime flow and easterly equatorial biases are experienced in the Météo-France climate model. These biases are found to be much reduced when a simple parameterization is introduced to take into account the vertical momentum transfer through the gravity waves excited by deep convection. These waves are quasi-stationary in the frame of reference moving with convection and they propagate vertically to higher levels in the atmosphere, where they may exert a significant deceleration of the mean flow at levels where dissipation occurs. Sixty-day experiments have been performed from a multiyear simulation with the standard 31 levels for a summer and a winter month, and with a T42 horizontal resolution. The impact of this parameterization on the integration of the model is found to be generally positive, with a significant deceleration in the westerly stratospheric jet and with a reduction of the easterly equatorial bias. The sensitivity of the Météo-France climate model to vertical resolution is also investigated by increasing the number of vertical levels, without moving the top of the model. The vertical resolution is increased up to 41 levels, using two kinds of level distribution. For the first, the increase in vertical resolution concerns especially the troposphere (with 22 levels in the troposphere), and the second treats the whole atmosphere in a homogeneous way (with 15 levels in the troposphere); the standard version of 31 levels has 10 levels in the troposphere. A comparison is made between the dynamical aspects of the simulations. The zonal wind and precipitation are presented and compared for each resolution. A positive impact is found with the finer tropospheric resolution on the precipitation in the mid-latitudes and on the westerly stratospheric jet, but the general impact on the model climate is weak, the physical parameterizations used appear to be mostly independent to the vertical resolution.Key words. Meteorology and atmospheric dynamics · Convective processes · Waves and tides

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Common volume satellite studies of polar mesospheric clouds with Odin/OSIRIS tomography and AIM/CIPS nadir imaging

10.5194/acp-2018-1035 ◽

2019 ◽

Cited By ~ 1

Author(s):

Lina Broman ◽

Susanne Benze ◽

Jörg Gumbel ◽

Ole-Martin Christensen ◽

Cora E. Randall

Keyword(s):

Water Content ◽

Correlation Coefficient ◽

Function Analysis ◽

Mass Density ◽

Horizontal Resolution ◽

Polar Mesospheric Clouds ◽

Error Characterization ◽

Ice Water Content ◽

Mesospheric Clouds ◽

Ice Water

Abstract. Two important approaches for satellite studies of Polar Mesospheric Clouds (PMC) are nadir measurements adapting phase function analysis and limb measurements adapting spectroscopic analysis. Combining both approaches enables new studies of cloud structures and microphysical processes but is complicated by differences in scattering conditions, observation geometry, and sensitivity. In this study, we compare common volume PMC observations from the nadir viewing Cloud Imaging and Particle Size instrument (CIPS) on the AIM satellite and a special set of tomographic limb observations from the Optical Spectrograph and InfraRed Imager System (OSIRIS) on the Odin satellite. While CIPS provides preeminent horizontal resolution, the OSIRIS tomographic analysis provides combined horizontal and vertical PMC information. This first direct comparison is an important step towards co-analyzing CIPS and OSIRIS data, aiming at unprecedented insights into horizontal and vertical cloud processes. We perform the first thorough error characterization of OSIRIS tomographic cloud brightness and cloud ice. We establish a consistent method for comparing cloud properties from limb tomography and nadir observations, accounting for differences in scattering conditions, resolution and sensitivity. Based on an extensive common volume, and a temporal coincidence criterion of only 5 minutes, our method enables a detailed comparison of PMC regions of varying brightness and ice content. We find that the primary OSIRIS tomography product, cloud scattering coefficient, shows very good agreement with the primary CIPS product, cloud albedo with a correlation coefficient of 0.96. However, OSIRIS systematically reports brighter clouds than CIPS and the bias between the instruments (OSIRIS – CIPS) is 3.4e−6 sr−1 (±2.9e−6 sr−1) on average. The OSIRIS tomography ice mass density agrees well with the CIPS ice water content, with a correlation coefficient of 0.91. However, the ice water content reported by OSIRIS is lower than CIPS, and we quantify the bias to −22 g km−2 (±14 g km−2) on average.

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High ice water content at low radar reflectivity near deep convection – Part 1: Consistency of in situ and remote-sensing observations with stratiform rain column simulations

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-15-16505-2015 ◽

2015 ◽

Vol 15 (12) ◽

pp. 16505-16550 ◽

Cited By ~ 1

Author(s):

A. M. Fridlind ◽

A. S. Ackerman ◽

A. Grandin ◽

F. Dezitter ◽

M. Weber ◽

...

Keyword(s):

Water Content ◽

Size Distribution ◽

Power Loss ◽

Deep Convection ◽

Radar Reflectivity ◽

Size Distributions ◽

Stratiform Rain ◽

Ice Water Content ◽

Ice Water

Abstract. Occurrences of jet engine power loss and damage have been associated with flight through fully glaciated deep convection at −10 to −50 °C. Power loss events commonly occur during flight through radar reflectivity (Ze) less than 20–30 dBZ and no more than moderate turbulence, often overlying moderate to heavy rain near the surface. During 2010–2012 Airbus carried out flight tests seeking to characterize the highest ice water content (IWC) in such low-Ze regions of large, cold-topped storm systems in the vicinity of Cayenne, Darwin, and Santiago. Within the highest IWC regions encountered, at typical sampling elevations circa 11 km, the measured ice size distributions exhibit a notably narrow concentration of mass over area-equivalent diameters of 100–500 μm. Given substantial and poorly quantified measurement uncertainties, here we evaluate the consistency of the Airbus in situ measurements with ground-based profiling radar observations obtained under quasi-steady, heavy stratiform rain conditions in one of the Airbus-sampled locations. We find that profiler-observed radar reflectivities and mean Doppler velocities at Airbus sampling temperatures are generally consistent with those calculated from in situ size distribution measurements. We also find that column simulations using the in situ size distributions as an upper boundary condition are generally consistent with observed profiles of Ze, mean Doppler velocity, and retrieved rain rate. The results of these consistency checks motivate an examination of the microphysical pathways that could be responsible for the observed size distribution features in Part 2.

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Evolution of DARDAR-CLOUD ice cloud retrievals: new parameters and impacts on the retrieved microphysical properties

Atmospheric Measurement Techniques ◽

10.5194/amt-12-2819-2019 ◽

2019 ◽

Vol 12 (5) ◽

pp. 2819-2835 ◽

Cited By ~ 8

Author(s):

Quitterie Cazenave ◽

Marie Ceccaldi ◽

Julien Delanoë ◽

Jacques Pelon ◽

Silke Groß ◽

...

Keyword(s):

Water Content ◽

A Priori ◽

Cold Temperatures ◽

Ice Cloud ◽

Microphysical Properties ◽

Lidar Measurements ◽

Ice Water Content ◽

Lidar Ratio ◽

Ice Water ◽

The Impact

Abstract. In this paper we present the latest refinements brought to the DARDAR-CLOUD product, which contains ice cloud microphysical properties retrieved from the cloud radar and lidar measurements from the A-Train mission. Based on a large dataset of in situ ice cloud measurements, the parameterizations used in the microphysical model of the algorithm – i.e. the normalized particle size distribution, the mass–size relationship, and the parameterization of the a priori value of the normalized number concentration as a function of temperature – were assessed and refined to better fit the measurements, keeping the same formalism as proposed in DARDAR basis papers. Additionally, in regions where lidar measurements are available, the lidar ratio retrieved for ice clouds is shown to be well constrained by the lidar–radar synergy. Using this information, the parameterization of the lidar ratio was also refined, and the new retrieval equals on average 35±10 sr in the temperature range between −60 and −20 ∘C. The impact of those changes on the retrieved ice cloud properties is presented in terms of ice water content (IWC) and effective radius. Overall, IWC values from the new DARDAR-CLOUD product are on average 16 % smaller than the previous version, leading to a 24 % reduction in the ice water path. In parallel, the retrieved effective radii increase by 5 % to 40 %, depending on temperature and the availability of the instruments, with an average difference of +15 %. Modifications of the microphysical model strongly affect the ice water content retrievals with differences that were found to range from −50 % to +40 %, depending on temperature and the availability of the instruments. The largest differences are found for the warmest temperatures (between −20 and 0 ∘C) in regions where the cloud microphysical processes are more complex and where the retrieval is almost exclusively based on radar-only measurements. The new lidar ratio values lead to a reduction of IWC at cold temperatures, the difference between the two versions increasing from around 0 % at −30 ∘C to 70 % below −80 ∘C, whereas effective radii are not impacted.

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A prototype method for diagnosing high ice water content probability using satellite imager data

Atmospheric Measurement Techniques ◽

10.5194/amt-11-1615-2018 ◽

2018 ◽

Vol 11 (3) ◽

pp. 1615-1637 ◽

Cited By ~ 13

Author(s):

Christopher R. Yost ◽

Kristopher M. Bedka ◽

Patrick Minnis ◽

Louis Nguyen ◽

J. Walter Strapp ◽

...

Keyword(s):

Water Content ◽

Deep Convection ◽

Engine Performance ◽

Aircraft Engine ◽

High Mass ◽

Aviation Industry ◽

Cloud Optical Depth ◽

Geo Satellite ◽

Ice Water Content ◽

Ice Water

Abstract. Recent studies have found that ingestion of high mass concentrations of ice particles in regions of deep convective storms, with radar reflectivity considered safe for aircraft penetration, can adversely impact aircraft engine performance. Previous aviation industry studies have used the term high ice water content (HIWC) to define such conditions. Three airborne field campaigns were conducted in 2014 and 2015 to better understand how HIWC is distributed in deep convection, both as a function of altitude and proximity to convective updraft regions, and to facilitate development of new methods for detecting HIWC conditions, in addition to many other research and regulatory goals. This paper describes a prototype method for detecting HIWC conditions using geostationary (GEO) satellite imager data coupled with in situ total water content (TWC) observations collected during the flight campaigns. Three satellite-derived parameters were determined to be most useful for determining HIWC probability: (1) the horizontal proximity of the aircraft to the nearest overshooting convective updraft or textured anvil cloud, (2) tropopause-relative infrared brightness temperature, and (3) daytime-only cloud optical depth. Statistical fits between collocated TWC and GEO satellite parameters were used to determine the membership functions for the fuzzy logic derivation of HIWC probability. The products were demonstrated using data from several campaign flights and validated using a subset of the satellite–aircraft collocation database. The daytime HIWC probability was found to agree quite well with TWC time trends and identified extreme TWC events with high probability. Discrimination of HIWC was more challenging at night with IR-only information. The products show the greatest capability for discriminating TWC  ≥  0.5 g m−3. Product validation remains challenging due to vertical TWC uncertainties and the typically coarse spatio-temporal resolution of the GEO data.

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