Characterizing Arctic mixed‐phase cloud structure and its relationship with humidity and temperature inversion using ARM NSA observations

Qiu, Shaoyue; Dong, Xiquan; Xi, Baike; Li, J.-L. F.

doi:10.1002/2014jd023022

Cited by 23 publications

(33 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This result is similar to results found by Kim et al (2008) differ by about 0.20. In a stable atmosphere with high LTS it appears that ACI net LWP increases more strongly in response to aerosols than in unstable environments (Klein and Hartmann, 1993;Qiu et al, 2015).…”

Section: Discussionmentioning

confidence: 99%

Effects of long-range aerosol transport on the microphysical properties of low-level liquid clouds in the Arctic

et al. 2016

View full text Add to dashboard Cite

Abstract. The properties of low-level liquid clouds in the Arctic can be altered by long-range pollution transport to the region. Satellite, tracer transport model, and meteorological data sets are used here to determine a net aerosol-cloud interaction (ACI net ) parameter that expresses the ratio of relative changes in cloud microphysical properties to relative variations in pollution concentrations while accounting for dry or wet scavenging of aerosols en route to the Arctic. For a period between 2008 and 2010, ACI net is calculated as a function of the cloud liquid water path, temperature, altitude, specific humidity, and lower tropospheric stability. For all data, ACI net averages 0.12±0.02 for cloud-droplet effective radius and 0.16±0.02 for cloud optical depth. It increases with specific humidity and lower tropospheric stability and is highest when pollution concentrations are low. Carefully controlling for meteorological conditions we find that the liquid water path of arctic clouds does not respond strongly to aerosols within pollution plumes. Or, not stratifying the data according to meteorological state can lead to artificially exaggerated calculations of the magnitude of the impacts of pollution on arctic clouds.

show abstract

Section: Discussionmentioning

confidence: 99%

Effects of long-range aerosol transport on the microphysical properties of low-level liquid clouds in the Arctic

et al. 2016

View full text Add to dashboard Cite

show abstract

“…On a regional scale, low-level MPCs were studied extensively in the Arctic, where they occur frequently and are persistent [67,78,89,103]. MPCs may be stabilized due to anthropogenic activity due to the deactivation effect [25] such that the sulfate-induced inhibition of freezing leads to fewer and larger ice crystals both in MPCs and pure ice clouds [27].…”

Section: Aerosol Effects On Stratiform and Shallow Convective Mpcsmentioning

confidence: 99%

Anthropogenic Aerosol Influences on Mixed-Phase Clouds

Lohmann

2017

Curr Clim Change Rep

View full text Add to dashboard Cite

Aerosol effects on mixed-phase clouds (MPCs) are more complex than in warm clouds because aerosol particles can act both as cloud condensation nuclei and as ice nucleating particles and more microphysical pathways exist. Stratiform MPCs are most prevalent in the Arctic where cloud top cooling enables heterogeneous ice formation and in orographic terrain where large updrafts prevail. Recently, aerosol effects on stratiform MPCs have also been considered in global climate models. The estimated effective aerosol radiative forcing due to aerosol-cloud and aerosol-radiation interactions (ERFaci+ari) at the top-ofthe-atmosphere (TOA) in stratiform warm and MPCs, which is an update of the estimate given in the fifth assessment report (AR5) of the Intergovernmental Panel of Climate Change, is −1.2 W m −2 with a 5-95 % range between −0.8 and −2.0 W m −2 . Since AR5, only one new estimate of ERFaci+ari including aerosol effects on both stratiform and convective clouds of −1.4 W m −2 has been published. In all cases, ERFaci+ari is dominated by changes in the shortwave TOA radiation with changes in the longwave TOA radiation amounting to 0.15 W m −2 .

show abstract

“…It is because results shown here are the median values and relative frequency distributions for all sounding profiles; if inversions exhibited at different levels relative to the cloud, they will be averaged out. Statistics of the inversions on a profile‐by‐profile basis would show a different result, as was done in Qiu et al (). The specific humidity inversions below the cloud base could be due to the deposition of water vapor on the falling ice crystals in the sub‐cloud layer, which would cause the specific humidity to decrease.…”

Section: Resultsmentioning

confidence: 95%

“…That is, the strong backscatter data from the ceilometer and MPL, combined with the small depolarization ratio from the MPL, indicate the existence of liquid phase droplets in this layer. Qiu et al () found that the MPL‐defined Z b is usually several hundred meters to 1 km lower than the ceilometer Z b . In the region between Z b,MPL and Z b,ceil , the backscatter data range from 8 to 30 × 10 −6 /m·sr, the depolarization data fall between a range of 0.1–0.5, and the Doppler velocity is often less than 1 m/s (Qiu et al, ).…”

Section: Methodsmentioning

confidence: 99%

“…Qiu et al () found that the MPL‐defined Z b is usually several hundred meters to 1 km lower than the ceilometer Z b . In the region between Z b,MPL and Z b,ceil , the backscatter data range from 8 to 30 × 10 −6 /m·sr, the depolarization data fall between a range of 0.1–0.5, and the Doppler velocity is often less than 1 m/s (Qiu et al, ). Therefore, this layer between the two cloud bases should be defined as ice cloud, in which Z b,MPL defines the lower boundary of the ice layer.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Influence of Wind Direction on Thermodynamic Properties and Arctic Mixed‐Phase Clouds in Autumn at Utqiaġvik, Alaska

Qiu

Dong

2018

JGR Atmospheres

Self Cite

View full text Add to dashboard Cite

Seven years of autumnal ground‐based observations (September–November 2002–2008) at the U.S. Department of Energy Atmospheric Radiation Measurement North Slope of Alaska site have been analyzed for addressing the occurrence frequency and macrophysical and microphysical properties of Arctic mixed‐phase clouds (AMC), as well as the relationship between environmental parameters and AMC properties. In September and October, AMC occurrence frequency is 20–30% lower during a southerly wind when compared to the other wind directions; in November, the variation of AMC occurrence frequency with wind direction is small. The mean liquid water path in November is about half of that in October and September. When the surface is snow free, temperature (T) and specific humidity (q) profiles during a northerly wind are warmer and moister than those for the southerly wind. Northerly wind profiles have a higher relative humidity to ice (RHi) and lower atmosphere stability. Furthermore, the AMC occurrence frequency has a positive relationship with RHi and a negative relationship with stability. These two points may explain the lower AMC occurrence frequency during a southerly wind. During a northerly wind, AMCs have larger radar reflectivity, wider spectrum width, and larger Doppler velocity signatures. The stronger precipitation for AMC during a northerly wind is possibly due to the cleaner air masses from the ocean (north). With the same amount of q, the radar spectrum width has a higher frequency in the larger bins during a northerly wind. Both T, q, and radar reflectivity, radar spectrum width profiles show evidence of deposition in the sub‐cloud layer in September and October.

show abstract

Characterizing Arctic mixed‐phase cloud structure and its relationship with humidity and temperature inversion using ARM NSA observations

Cited by 23 publications

References 37 publications

Effects of long-range aerosol transport on the microphysical properties of low-level liquid clouds in the Arctic

Effects of long-range aerosol transport on the microphysical properties of low-level liquid clouds in the Arctic

Anthropogenic Aerosol Influences on Mixed-Phase Clouds

Influence of Wind Direction on Thermodynamic Properties and Arctic Mixed‐Phase Clouds in Autumn at Utqiaġvik, Alaska

Contact Info

Product

Resources

About