Impact of the Atmospheric Thickness on the Atmospheric Downwelling Longwave Radiation and Snowmelt under Clear-Sky Conditions in the Arctic and Subarctic

Zhang, Tingjun; Stamnes, Knut; Bowling, Sue Ann

doi:10.1175/1520-0442(2001)014<0920:iotato>2.0.co;2

Cited by 63 publications

(51 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As a result of warmer temperatures and higher water vapor content in the lowest few kilometers, longwave clear-sky atmospheric radiative emission is enhanced during the 1st regime compare to the 3rd, partially masking the cloud LWF during the 1st regime. This is consistent with the findings of Zhang et al (2001). Total CRF reflected this shift in both SWF and LWF.…”

Section: Cloud Radiative Forcingsupporting

confidence: 92%

A transitioning Arctic surface energy budget: the impacts of solar zenith angle, surface albedo and cloud radiative forcing

et al. 2010

View full text Add to dashboard Cite

Snow surface and sea-ice energy budgets were measured near 87.5°N during the Arctic Summer Cloud Ocean Study (ASCOS), from August to early September 2008. Surface temperature indicated four distinct temperature regimes, characterized by varying cloud, thermodynamic and solar properties. An initial warm, melt-season regime was interrupted by a 3-day cold regime where temperatures dropped from near zero to -7°C. Subsequently mean energy budget residuals remained small and near zero for 1 week until once again temperatures dropped rapidly and the energy budget residuals became negative. Energy budget transitions were dominated by the net radiative fluxes, largely controlled by the cloudiness. Variable heat, moisture and cloud distributions were associated with changing airmasses. Surface cloud radiative forcing, the net radiative effect of clouds on the surface relative to clear skies, is estimated. Shortwave cloud forcing ranged between -50 W m -2 and zero and varied significantly with surface albedo, solar zenith angle and cloud liquid water. Longwave cloud forcing was larger and generally ranged between 65 and 85 W m -2 , except when the cloud fraction was tenuous or contained little liquid water; thus the net effect of the clouds was to warm the surface. Both cold periods occurred under tenuous, or altogether absent, low-level clouds containing little liquid water, effectively reducing the cloud greenhouse effect. Freeze-up progression was enhanced by a combination of increasing solar zenith angles and surface albedo, while inhibited by a large, positive surface cloud forcing until a new air-mass with considerably less cloudiness advected over the experiment area.

show abstract

Section: Cloud Radiative Forcingsupporting

confidence: 92%

A transitioning Arctic surface energy budget: the impacts of solar zenith angle, surface albedo and cloud radiative forcing

et al. 2010

View full text Add to dashboard Cite

show abstract

“…Svensson and Karlsson [2011] found that it is primarily the q profile and not the temperature profile that determines the clear-air L # in very cold and dry conditions and hence that the atmospheric moisture content is very important for the radiation balance at the Arctic surface. Results by Zhang et al [2001] also indicated that changes in the atmospheric precipitable water have a higher impact on L # than the change in mean atmospheric temperature. Finally, the amount of turbulent mixing is varied by both adjusting the eddy diffusivity coefficient for heat, momentum, and moisture K in the BL scheme, and the exchange coefficients C for heat, momentum, and moisture in the LSM to adjust the mixing in the surface layer.…”

Section: Sensitivity and Process Analysesmentioning

confidence: 97%

The role of snow‐surface coupling, radiation, and turbulent mixing in modeling a stable boundary layer over Arctic sea ice

2013

View full text Add to dashboard Cite

[1] To enhance the understanding of the impact of small-scale processes in the polar climate, this study focuses on the relative role of snow-surface coupling, radiation and turbulent mixing in an Arctic stable boundary layer. We extend the GABLS1 (GEWEX Atmospheric Boundary-Layer Study 1) model intercomparison for turbulent mixing with the other relevant physical processes in the stable boundary layer over sea ice. We use the Single Column Model (SCM) version of the Weather Research and Forecasting (WRF) mesoscale meteorological model and run different combinations of boundary layer and radiation schemes, using a state-of-the art land surface scheme. With this intercomparison of schemes, we confirm a wide variety in the state of the atmosphere and the surface variables for the selected parameterization schemes. To understand this variety, a sensitivity analysis for one particular combination of parameterization schemes is performed, using a novel analysis method of process diagrams. The variation between the sensitivity runs indicates a relative orientation of model sensitivities to variations in each of the governing processes and these can explain the variety of model results obtained in the intercomparison of different parameterization schemes. Moreover, we apply the same method for several geostrophic wind speeds to represent a large range of synoptic conditions. Results indicate a shift in process significance for different wind regimes. For low wind regimes, the model sensitivity is larger for surface coupling and radiation, while for high wind speeds, the largest sensitivity is found for the turbulent mixing process. An interesting non-linear feature was found for turbulent mixing for frequently occurring wind speeds and low wind speed cases, where the 2 m temperature increases for decreased amounts of mixing.

show abstract

“…In particular, an increase in water vapor in the case of low water vapor content results in a remarkable increase in downward longwave radiation. According to observational results from Alaska (Zhang et al, 2001), downward longwave radiation increases logarithmically with increasing precipitable water; that is, an increase in precipitable water from 2 to 5 kg m −2 corresponds to a rapid increase in downward longwave radiation from 130 to 200 W m −2 . The same relationship between precipitable water and downward longwave radiation is apparent in the Lena River Basin (Figures 5(b) and 9).…”

Section: Wet Air Advectionmentioning

confidence: 99%

“…Variations in downward longwave radiation account for interannual variability in snowmelt within the Arctic and Subarctic, as deduced from atmospheric radiative transfer modeling (Zhang et al, 1997). Zhang et al (2001) proposed that atmospheric thickness had a positive impact on downward longwave radiation, and that increasing the atmospheric thickness was sufficient to trigger the onset of snowmelt. Wang et al (2001) used a one-dimensional turbulence closure-snow model to demonstrate that low-level clouds increase the snow surface temperature in the Arctic by enhancing downward longwave radiation.…”

Section: Introductionmentioning

confidence: 99%

Snow disappearance in Eastern Siberia and its relationship to atmospheric influences

Iijima

Masuda

Ohata

2006

Intl Journal of Climatology

View full text Add to dashboard Cite

Abstract:In the present study, we examine the climatological features and interannual variations in snow disappearance within the Lena River Basin, Eastern Siberia, during a recent 15-year period (1986)(1987)(1988)(1989)(1990)(1991)(1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000), and the relationship of snow disappearance to atmospheric conditions. According to the climatology of the day of the year on which snow disappears, the boundary of snow disappearance within the Lena River Basin migrates rapidly northward from mid-April until early June, with minimum interannual variation occurring in the middle part of the basin. In addition, the preceding snow disappearance is apparent in the central Lena River Basin. Melting of snow within the Lena River Basin commonly occurs within 30 days of complete snow disappearance under certain atmospheric conditions: daily mean air temperature in excess of −10°C, greater than 2 hPa of water vapor pressure, and, hence, more than 170 W m −2 of downward longwave radiation under clear sky conditions. Composite analysis using a reanalysis dataset demonstrates that the increase in air temperature and water vapor that accompanies snow melting is due to wet (and warm) air advection in conjunction with enhanced water vapor convergence over the central Lena River Basin during the 30-day period prior to snow disappearance.

show abstract

Impact of the Atmospheric Thickness on the Atmospheric Downwelling Longwave Radiation and Snowmelt under Clear-Sky Conditions in the Arctic and Subarctic

Cited by 63 publications

References 24 publications

A transitioning Arctic surface energy budget: the impacts of solar zenith angle, surface albedo and cloud radiative forcing

A transitioning Arctic surface energy budget: the impacts of solar zenith angle, surface albedo and cloud radiative forcing

The role of snow‐surface coupling, radiation, and turbulent mixing in modeling a stable boundary layer over Arctic sea ice

Snow disappearance in Eastern Siberia and its relationship to atmospheric influences

Contact Info

Product

Resources

About