The day-to-day co-variability between mineral dust and cloud glaciation: a proxy for heterogeneous freezing

Abstract. To estimate the global co-variability between mineral dust aerosol and cloud glaciation, we combined an aerosol model reanalysis with satellite retrievals of cloud thermodynamic phase. We used the CALIPSO-GOCCP product from the A-Train satellite constellation to assess whether clouds are composed of liquid or ice and the MACC reanalysis to estimate the dust mixing ratio in the atmosphere. Night-time retrievals within a temperature range from +3 to −42 ∘C for the period 2007–2010 were included. The results confirm that the cloud thermodynamic phase is highly dependent on temperature and latitude. However, at middle and high latitudes, at equal temperature and within narrow constraints for humidity and static stability, the average frequency of fully glaciated clouds increases by +5 to +10 % for higher mineral dust mixing ratios. The discrimination between humidity and stability regimes reduced the confounding influence of meteorology on the observed relationship between dust and cloud ice. Furthermore, for days with similar mixing ratios of mineral dust, the cloud ice occurrence frequency in the Northern Hemisphere was found to be higher than in the Southern Hemisphere at −30 ∘C but lower at −15 ∘C. This contrast may suggest a difference in the susceptibility of cloud glaciation to the presence of dust. Based on previous studies, the differences at −15 ∘C could be explained by higher feldspar fractions in the Southern Hemisphere, while the higher freezing efficiency of clay minerals in the Northern Hemisphere may explain the differences at −30 ∘C.

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The day-to-day co-variability between mineral dust and cloud glaciation: A proxy for heterogeneous freezing

10.5194/acp-2019-661 ◽

2019 ◽

Author(s):

Diego Villanueva ◽

Bernd Heinold ◽

Patric Seifert ◽

Hartwig Deneke ◽

Martin Radenz ◽

...

Keyword(s):

Southern Hemisphere ◽

Northern Hemisphere ◽

Mineral Dust ◽

Average Frequency ◽

Static Stability ◽

Night Time ◽

Aerosol Model ◽

Mixing Ratios ◽

Cloud Ice ◽

Thermodynamic Phase

Abstract. To estimate the global co-variability between mineral dust aerosol and cloud glaciation, an aerosol model reanalysis was combined with satellite retrievals of cloud thermodynamic phase. We used the CALIPSO-GOCCP and DARDAR products from the A-Train satellite constellation to obtain the cloud phase and the MACC reanalysis to estimate the dust mixing-ratio in the atmosphere. Night-time retrievals within a temperature range from +3 °C to −42 °C for the period 2007–2010 were included. The results confirm that the cloud thermodynamic phase is highly dependent on temperature and latitude. However, at mid- and high latitudes, at equal temperature and within narrow constrains for humidity and static stability the average frequency of fully glaciated clouds increase by +5 to +10 % for higher mineral dust mixing-ratios. The differentiation between humidity-stability regimes reduced the confounding influence of meteorology on the observed relationship between dust and cloud ice. Furthermore, for similar mixing-ratios of mineral dust the cloud ice occurrence-frequency in the Northern Hemisphere was found to be higher than in the Southern Hemisphere at −30 °C but lower at −15 °C. This may suggest a difference in the susceptibility of cloud glaciation to the presence of dust. Based on previous studies, the differences at −15 °C could be explained by higher feldspar fractions in the Southern Hemisphere, while the differences at −30 °C may be explained by the higher freezing efficiency of clay minerals in the Northern Hemisphere.

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The impact of mineral dust on the day-to-day variability of stratiform cloud glaciation occurrence

10.5194/acp-2018-1074 ◽

2018 ◽

Author(s):

Diego Villanueva ◽

Bernd Heinold ◽

Patric Seifert ◽

Hartwig Deneke ◽

Martin Radenz ◽

...

Keyword(s):

Mineral Dust ◽

High Latitudes ◽

Night Time ◽

Aerosol Model ◽

Mixing Ratios ◽

Ice Cloud ◽

Stratiform Clouds ◽

Thermodynamic Phase ◽

The Impact ◽

Equal Temperature

Abstract. Two different A-Train satellite cloud phase products were analysed together with an aerosol model reanalysis to assess the global day-to-day variability of cloud thermodynamic phase. This variability was analysed for different mixing-ratios of fine and coarse mineral dust during the period 2007–2010 and within a temperature range from +3 °C to −42 °C. Night‑time stratiform clouds were analysed, including stratocumulus, altocumulus, altostratus and cirrus clouds. This analysis showed that the phase of stratiform clouds is highly dependent on temperature and latitude. However, at equal temperature the average occurrence of fully glaciated stratiform clouds was found to increase for higher dust mixing-ratios on a day-to-day basis at mid- and high latitudes. At −15 °C, the increment of ice cloud occurrence between the lowest and highest mixing-ratio was found to be higher for fine dust (+10 % to +18 % occurrence) than for coarse dust (+5 % to +10 %). Surprisingly, the increments were higher in remote regions (e.g. southern high latitudes) where the average dust-mixing ratios are low.

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Global upper-tropospheric formaldehyde: seasonal cycles observed by the ACE-FTS satellite instrument

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-9-1051-2009 ◽

2009 ◽

Vol 9 (1) ◽

pp. 1051-1095 ◽

Cited By ~ 1

Author(s):

G. Dufour ◽

S. Szopa ◽

M. P. Barkley ◽

C. D. Boone ◽

A. Perrin ◽

...

Keyword(s):

Southern Hemisphere ◽

Northern Hemisphere ◽

Biomass Burning ◽

Growing Season ◽

Global Scale ◽

Tropospheric Chemistry ◽

Data Set ◽

Mixing Ratios ◽

Good Reproduction ◽

Summer Maximum

Abstract. Seasonally-resolved upper tropospheric profiles of formaldehyde (HCHO) observed by the ACE Fourier transform spectrometer (ACE-FTS) on a near-global scale are presented for the time period from March 2004 to November 2006. Large upper tropospheric HCHO mixing ratios (>150 pptv) are observed during the growing season of the terrestrial biosphere in the Northern Hemisphere and during the biomass burning season in the Southern Hemisphere. The total errors estimated for the retrieved mixing ratios range from 30 to 40% in the upper troposphere and increase in the lower stratosphere. The sampled HCHO concentrations are in satisfactory agreement with previous aircraft and satellite observations with a negative bias (<25%) within observation errors. An overview of the seasonal cycle of the upper tropospheric HCHO is given for different latitudes. A maximum is observed during summer, i.e. during the growing season, in the northern mid- and high latitudes. The influence of biomass burning is visible in HCHO upper tropospheric concentrations during the September-to-October period in the southern tropics and subtropics. Comparisons with two state-of-the-art models (GEOS-Chem and LMDz-INCA) show that the models fail to reproduce the seasonal variations observed in the southern tropics and subtropics but they capture well the variations observed in the Northern Hemisphere (correlation >0.9). Both models underestimate the summer maximum over Europe and Russia and differences in the emissions used for North America result in a good reproduction of the summer maximum by GEOS-Chem but in an underestimate by LMDz-INCA. Globally, GEOS-Chem reproduces well the observations on average over one year but has some difficulties in reproducing the spatial variability of the observations. LMDz-INCA shows significant bias in the Southern Hemisphere, likely related to an underestimation of methane, but better reproduces the temporal and spatial variations. The differences between the models underline the large uncertainties that remain in the emissions of HCHO precursors. Observations of the HCHO upper tropospheric profile provided by the ACE-FTS represent a unique data set for investigating and improving our current understanding of the formaldehyde budget and upper tropospheric chemistry.

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Constraining ice nuclei freezing efficiency using cloud phase observations together with climate models.

10.5194/egusphere-egu21-8478 ◽

2021 ◽

Author(s):

Diego Villanueva

Keyword(s):

Black Carbon ◽

Climate Models ◽

Climate Model ◽

Mineral Dust ◽

Dust Aerosol ◽

Strong Constraint ◽

Aerosol Model ◽

Aerosol Cloud Interactions ◽

Thermodynamic Phase ◽

The Impact

Aerosol-cloud interactions are an important source of uncertainty in current climate models. In particular, the role of mineral dust and soot particles in cloud glaciation is poorly understood. This lack of understanding leads to high uncertainty in climate predictions.To estimate the global co-variability between mineral dust aerosol and cloud glaciation, we combined an aerosol model reanalysis with satellite retrievals of cloud thermodynamic phase. Our results confirmed that the cloud thermodynamic phase increases with higher mineral dust concentrations.To better understand and quantify the impact of ice-nucleating particles on cloud glaciation, it is crucial to have a reliable estimation of the hemispheric and seasonal contrast in cloud top phase, which is believed to result from the higher dust aerosol loading in boreal spring. For this reason, we locate and quantify these contrasts by combining three different A-Train cloud-phase products for the period 2007-2010. These products rely on a spaceborne lidar, a lidar-radar synergy, and a radiometer-polarimeter synergy. We used these observations to constrain the droplet freezing in the ECHAM-HAM climate model. After tuning, the model leads to more realistic cloud-top-phase contrasts and a dust-driven glaciation effect of 0.14 &#177; 0.13 Wm&#8722;2 between 30&#8211;60&#176;N. Our results show that using observations of cloud-top phase contrasts provide a strong constraint for ice formation in mixed-phase clouds and a weak constraint for the associated impact on radiation and precipitation.Besides mineral dust, it has been under debate whether black carbon also contributes to cloud glaciation. Therefore, we studied the cloud top phase retrieved by CALIOP during the Australian wildfires in 2020. After repeating the tuning strategy for black carbon, we were able to replicate the increase in ice cloud frequency observed during the wildfires.

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Observations of the mesospheric semi-annual oscillation (MSAO) in water vapour by Odin/SMR

Atmospheric Chemistry and Physics ◽

10.5194/acp-8-6527-2008 ◽

2008 ◽

Vol 8 (21) ◽

pp. 6527-6540 ◽

Cited By ~ 18

Author(s):

S. Lossow ◽

J. Urban ◽

J. Gumbel ◽

P. Eriksson ◽

D. Murtagh

Keyword(s):

Water Vapour ◽

Southern Hemisphere ◽

Northern Hemisphere ◽

Annual Variation ◽

Equatorial Region ◽

Peak Amplitude ◽

Altitude Range ◽

Double Peak Structure ◽

Latitude Range ◽

Mixing Ratios

Abstract. Mesospheric water vapour measurements taken by the SMR instrument aboard the Odin satellite between 2002 and 2006 have been analysed with focus on the mesospheric semi-annual circulation in the tropical and subtropical region. This analysis provides the first complete picture of mesospheric SAO in water vapour, covering altitudes above 80 km where previous studies were limited. Our analysis shows a clear semi-annual variation in the water vapour distribution in the entire altitude range between 65 km and 100 km in the equatorial area. Maxima occur near the equinoxes below 75 km and around the solstices above 80 km. The phase reversal occurs in the small layer in-between, consistent with the downward propagation of the mesospheric SAO in the zonal wind in this altitude range. The SAO amplitude exhibits a double peak structure in the equatorial region, with maxima at about 75 km and 81 km. The observed amplitudes show higher values than an earlier analysis based on UARS/HALOE data. The upper peak amplitude remains relatively constant with latitude. The lower peak amplitude decreases towards higher latitudes, but recovers in the Southern Hemisphere subtropics. On the other hand, the annual variation is much more prominent in the Northern Hemisphere subtropics. Furthermore, higher volume mixing ratios during summer and lower values during winter are observed in the Northern Hemisphere subtropics, as compared to the corresponding latitude range in the Southern Hemisphere.

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Hydrogen cyanide in the upper troposphere: GEM-AQ simulation and comparison with ACE-FTS observations

Atmospheric Chemistry and Physics ◽

10.5194/acp-9-4301-2009 ◽

2009 ◽

Vol 9 (13) ◽

pp. 4301-4313 ◽

Cited By ~ 27

Author(s):

A. Lupu ◽

J. W. Kaminski ◽

L. Neary ◽

J. C. McConnell ◽

K. Toyota ◽

...

Keyword(s):

Seasonal Variation ◽

Southern Hemisphere ◽

Northern Hemisphere ◽

Atmospheric Chemistry ◽

Hydrogen Cyanide ◽

Boreal Summer ◽

Air Quality Model ◽

Upper Troposphere ◽

Mixing Ratios ◽

The Tropics

Abstract. We investigate the spatial and temporal distribution of hydrogen cyanide (HCN) in the upper troposphere through numerical simulations and comparison with observations from a space-based instrument. To perform the simulations, we used the Global Environmental Multiscale Air Quality model (GEM-AQ), which is based on the three-dimensional global multiscale model developed by the Meteorological Service of Canada for operational weather forecasting. The model was run for the period 2004–2006 on a 1.5°×1.5° global grid with 28 hybrid vertical levels from the surface up to 10 hPa. Objective analysis data from the Canadian Meteorological Centre were used to update the meteorological fields every 24 h. Fire emission fluxes of gas species were generated by using year-specific inventories of carbon emissions with 8-day temporal resolution from the Global Fire Emission Database (GFED) version 2. The model output is compared with HCN profiles measured by the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) instrument onboard the Canadian SCISAT-1 satellite. High values of up to a few ppbv are observed in the tropics in the Southern Hemisphere; the enhancement in HCN volume mixing ratios in the upper troposphere is most prominent in October. Low upper-tropospheric mixing ratios of less than 100 pptv are mostly recorded at middle and high latitudes in the Southern Hemisphere in May–July. Mixing ratios in Northern Hemisphere peak in the boreal summer. The amplitude of the seasonal variation is less pronounced than in the Southern Hemisphere. The comparison with the satellite data shows that in the upper troposphere GEM-AQ performs well globally for all seasons, except at northern high and middle latitudes in summer, where the model has a large negative bias, and in the tropics in winter and spring, where it exhibits large positive bias. This may reflect inaccurate emissions or possible inaccuracies in the emission profile. The model is able to explain most of the observed variability in the upper troposphere HCN field, including the interannual variations in the observed mixing ratio. A complementary comparison with daily total columns of HCN from two middle latitude ground-based stations in Northern Japan for the same simulation period shows that the model captures the observed seasonal variation and also points to an underestimation of model emissions in the Northern Hemisphere in the summer. The estimated average global emission equals 1.3 Tg N yr−1. The average atmospheric burden is 0.53 Tg N, and the corresponding lifetime is 4.9 months.

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Intercomparison of ILAS-II version 1.4 and version 2 target parameters with MIPAS-Envisat measurements

Atmospheric Chemistry and Physics ◽

10.5194/acp-8-825-2008 ◽

2008 ◽

Vol 8 (4) ◽

pp. 825-843 ◽

Cited By ~ 10

Author(s):

A. Griesfeller ◽

T. von Clarmann ◽

J. Griesfeller ◽

M. Höpfner ◽

M. Milz ◽

...

Keyword(s):

Quantitative Analysis ◽

Data Quality ◽

Southern Hemisphere ◽

Northern Hemisphere ◽

Quality Evaluation ◽

Mixing Ratios ◽

The Mean ◽

Mean Differences

Abstract. This paper assesses the mean differences between the two ILAS-II data versions (1.4 and 2) by comparing them with MIPAS measurements made between May and October 2003. For comparison with ILAS-II results, MIPAS data processed at the Institut für Meteorologie und Klimaforschung, Karlsruhe, Germany (IMK) in cooperation with the Instituto de Astrofísica de Andalucía (IAA) in Granada, Spain, were used. The coincidence criteria of ±300 km in space and ±12 h in time for H2O, N2O, and CH4 and the coincidence criteria of ±300 km in space and ±6 h in time for ClONO2, O3, and HNO3 were used. The ILAS-II data were separated into sunrise (= Northern Hemisphere) and sunset (= Southern Hemisphere). For the sunrise data, a clear improvement from version 1.4 to version 2 was observed for H2O, CH4, ClONO2, and O3. In particular, the ILAS-II version 1.4 mixing ratios of H2O and CH4 were unrealistically small, and those of ClONO2 above altitudes of 30 km unrealistically large. For N2O and HNO3, there were no large differences between the two versions. Contrary to the Northern Hemisphere, where some exceptional profiles deviated significantly from known climatology, no such outlying profiles were found in the Southern Hemisphere for both versions. Generally, the ILAS-II version 2 data were in better agreement with the MIPAS data than the version 1.4, and are recommended for quantitative analysis in the stratosphere. For H2O data in the Southern Hemisphere, further data quality evaluation is necessary.

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Abiotic and biogeochemical signals derived from the seasonal cycles of tropospheric nitrous oxide

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-10-25803-2010 ◽

2010 ◽

Vol 10 (11) ◽

pp. 25803-25839

Author(s):

C. D. Nevison ◽

E. Dlugokencky ◽

G. Dutton ◽

J. W. Elkins ◽

P. Fraser ◽

...

Keyword(s):

Nitrous Oxide ◽

Interannual Variability ◽

Southern Hemisphere ◽

Northern Hemisphere ◽

Seasonal Cycle ◽

Coastal Upwelling ◽

Seasonal Cycles ◽

Mixing Ratios ◽

Stratospheric Temperature ◽

Deep Ocean Water

Abstract. Seasonal cycles in the mixing ratios of tropospheric nitrous oxide (N2O) are derived by detrending long-term measurements made at sites across four global surface monitoring networks. These cycles are examined for physical and biogeochemical signals. The detrended monthly data display large interannual variability, which at some sites challenges the concept of a "mean" seasonal cycle. The interannual variability in the seasonal cycle is not always correlated among networks that share common sites. In the Northern Hemisphere, correlations between detrended N2O seasonal minima and polar winter lower stratospheric temperature provide compelling evidence for a stratospheric influence, which varies in strength from year to year and can explain much of the interannual variability in the surface seasonal cycle. Even at sites where a strong, competing, regional N2O source exists, such as from coastal upwelling at Trinidad Head, California, the stratospheric influence must be understood in order to interpret the biogeochemical signal in monthly mean data. In the Southern Hemisphere, detrended surface N2O monthly means are correlated with polar lower stratospheric temperature in months preceding the N2O minimum, suggesting a coherent stratospheric influence in that hemisphere as well. A decomposition of the N2O seasonal cycle in the extratropical Southern Hemisphere suggests that ventilation of deep ocean water (microbially enriched in N2O) and the stratospheric influx make similar contributions in phasing, and may be difficult to disentangle. In addition, there is a thermal signal in N2O due to seasonal ingassing and outgassing of cooling and warming surface waters that is out of phase and thus competes with the stratospheric and ventilation signals. All the seasonal signals discussed above are subtle and are generally better quantified in high-frequency in situ data than in data from weekly flask samples, especially in the Northern Hemisphere. The importance of abiotic influences (thermal, stratospheric influx, and tropospheric transport) on N2O seasonal cycles suggests that, at many sites, surface N2O mixing ratio data by themselves are unlikely to provide information about seasonality in surface sources (e.g., for atmospheric inversions), but may be more powerful if combined with complementary data such as CFC-12 mixing ratios or N2O isotopes.

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Global stratospheric chlorine inventories for 2004–2009 from Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) measurements

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-13-23491-2013 ◽

2013 ◽

Vol 13 (9) ◽

pp. 23491-23548 ◽

Cited By ~ 2

Author(s):

A. T. Brown ◽

M. P. Chipperfield ◽

S. Dhomse ◽

C. Boone ◽

P. F. Bernath

Keyword(s):

Southern Hemisphere ◽

Northern Hemisphere ◽

Atmospheric Chemistry ◽

Transport Model ◽

Montreal Protocol ◽

Chemical Transport Model ◽

Mixing Ratios ◽

Ozone Depleting Substances ◽

The Tropics ◽

Chemistry Experiment

Abstract. We present chlorine budgets calculated between 2004 and 2009 for four latitude bands (70° N–30° N, 30° N–0° N, 0° N–30° S, and 30° S–70° S). The budgets were calculated using ACE-FTS version 3.0 retrievals of the volume mixing ratios (VMRs) of 9 chlorine-containing species: CCl4, CFC-12 (CCl2F2), CFC-11 (CCl3F), COCl2, COClF, HCFC-22 (CHF2Cl), CH3Cl, HCl and ClONO2. These data were supplemented with calculated VMRs from the SLIMCAT 3-D chemical transport model (CFC-113, CFC-114, CFC-115, H-1211, H-1301, HCFC-141b, HCFC-142b, ClO and HOCl). The total chlorine profiles are dominated by chlorofluorocarbons (CFCs) and halons up to 24 km in the tropics and 19 km in the extra-tropics. In this altitude range CFCs and halons account for 58% of the total chlorine VMR. Above this altitude HCl increasingly dominates the total chlorine profile, reaching a maximum of 95% of total chlorine at 54 km. All total chlorine profiles exhibit a positive slope with altitude, suggesting that the total chlorine VMR is now decreasing with time. This conclusion is supported by the time series of the mean stratospheric total chlorine budgets which show mean decreases in total stratospheric chlorine of 0.38 ± 0.03% per year in the Northern Hemisphere extra-tropics, 0.35 ± 0.07% per year in the Northern Hemisphere tropical stratosphere, 0.54 ± 0.16% per year in the Southern Hemisphere tropics and 0.53 ± 0.12% per year in the Southern Hemisphere extra-tropical stratosphere for 2004–2009. Globally stratospheric chlorine is decreasing by 0.46 ± 0.02% per year. Both global warming potential-weighted chlorine and ozone depletion potential-weighted chlorine are decreasing at all latitudes. These results show that the Montreal Protocol has had a significant effect in reducing emissions of both ozone-depleting substances and greenhouse gases.

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Global upper-tropospheric formaldehyde: seasonal cycles observed by the ACE-FTS satellite instrument

Atmospheric Chemistry and Physics ◽

10.5194/acp-9-3893-2009 ◽

2009 ◽

Vol 9 (12) ◽

pp. 3893-3910 ◽

Cited By ~ 35

Author(s):

G. Dufour ◽

S. Szopa ◽

M. P. Barkley ◽

C. D. Boone ◽

A. Perrin ◽

...

Keyword(s):

Southern Hemisphere ◽

Northern Hemisphere ◽

Biomass Burning ◽

Growing Season ◽

Global Scale ◽

High Latitudes ◽

Mixing Ratios ◽

Good Reproduction ◽

Summer Maximum ◽

One Year

Abstract. Seasonally-resolved upper tropospheric profiles of formaldehyde (HCHO) observed by the ACE Fourier transform spectrometer (ACE-FTS) on a near-global scale are presented for the time period from March 2004 to November 2006. Large upper tropospheric HCHO mixing ratios (>150 pptv) are observed during the growing season of the terrestrial biosphere in the Northern Hemisphere and during the biomass burning season in the Southern Hemisphere. The total errors estimated for the retrieved mixing ratios range from 30 to 40% in the upper troposphere and increase in the lower stratosphere. The sampled HCHO concentrations are in satisfactory agreement with previous aircraft and satellite observations with a negative bias (<25%) within observation errors. An overview of the seasonal cycle of the upper tropospheric HCHO is given for different latitudes, with a particular focus on mid-to-high latitudes that are well sampled by the observations. A maximum is observed during summer, i.e. during the growing season, in the northern mid- and high latitudes. The influence of biomass burning is visible in HCHO upper tropospheric concentrations during the September-to-October period in the southern tropics and subtropics. Comparisons with two state-of-the-art models (GEOS-Chem and LMDz-INCA) show that the models capture well the seasonal variations observed in the Northern Hemisphere (correlation >0.9). Both models underestimate the summer maximum over Europe and Russia and differences in the emissions used for North America result in a good reproduction of the summer maximum by GEOS-Chem but in an underestimate by LMDz-INCA. Globally, GEOS-Chem reproduces well the observations on average over one year but has some difficulties in reproducing the spatial variability of the observations. LMDz-INCA shows significant bias in the Southern Hemisphere, perhaps related to an underestimation of methane, but better reproduces the temporal and spatial variations. The differences between the models underline the large uncertainties that remain in the emissions of HCHO precursors.

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