Convective Patterns within a Field of Stratocumulus

Brümmer, Burghard; Busack, Birgit

doi:10.1175/1520-0493(1990)118<0801:cpwafo>2.0.co;2

Cited by 4 publications

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The resultant transformation of the air mass eventually leads to the formation of clouds which frequently take the form of cloud streets, roughly oriented along the winds in the outbreak. Farther downwind in the outbreak, the cloud streets transform into three-dimensional cells, occasionally of meander form [Brummer et al, 1992], sometimes as closed cells [Brummer and Busack, 1990] oceans, it is now known that large lakes can have significant effects on mesoscale convection in the overlying atmosphere and that this convection frequently takes the form of rolls. Much of the work on this topic has been undertaken over the Great Lakes of North America [Kelly, 1982[Kelly, , 1984.…”

Section: Introductionmentioning

confidence: 99%

Mesoscale shallow convection in the atmosphere

Atkinson¹,

Zhang²

1996

Reviews of Geophysics

336

371

View full text Add to dashboard Cite

This paper is a review of the observational, experimental, theoretical, and numerical studies of mesoscale shallow convection (MSC) in the atmosphere. Typically, MSC is 1 to 2 km deep, has a horizontal length scale of a few to a few tens of kilometers, and takes distinctive planforms: linear and hexagonal. The former is called a cloud street, roll, or band, while the latter is called mesoscale cellular convection (MCC), comprising three‐dimensional cells. MSC is characterized by its shape, horizontal extent, convective depth, and aspect ratio. The latter is the ratio of the horizontal extent to that in the vertical. For cells the horizontal extent is their diameter, whereas for rolls it is their spacing. Rolls usually align along or at angles of up to 10° from the mean horizontal wind of the convective layer, with lengths from 20 to 200 km, widths from 2 to 10 km, and convective depths from 2 to 3 km. The typical value of aspect ratio ranges from 2 to 20. Rolls may occur over both water surface and land surfaces. Mesoscale convective cells may be divided into two types: open and closed. Open‐cell circulation has downward motion and clear sky in the cell center, surrounded by cloud associated with upward motion. Closed cells have the opposite circulation. Both types of cell have diameters ranging from 10 to 40 km and aspect ratios of 5 to 50, and both occur in a convective layer with a depth of about 1 to 3 km. Both the magnitude and direction of horizontal wind in the convective layer change little with height. MSC results from a complex and incompletely understood mix of processes. These processes are outlined, and their interplay is examined through a review of theoretical and laboratory analyses and numerical modeling of MSC.

show abstract

Section: Introductionmentioning

confidence: 99%

Mesoscale shallow convection in the atmosphere

Atkinson¹,

Zhang²

1996

Reviews of Geophysics

336

371

View full text Add to dashboard Cite

show abstract

Cellular convection over the north‐eastern Atlantic

Bakan

Schwarz

1992

Intl Journal of Climatology

View full text Add to dashboard Cite

Convective clouds over the ocean frequently exhibit organized meso-scale patterns. A statistical evaluation of 4 years of NOAA satellite images over the north-eastern Atlantic yields climatological data of the appearance of these patterns and shows that open cellular convection is most abundant. For this convection type, surface and radiosonde data from Weathership M have been analysed. Open convection cells appear at a wide range of positive sea-air temperature differences up to 12"C.and at wind speeds up to 25 ms-'. All diameters have been found to be less than 80 km (average 41 km). Larger diameters are, on average, associated with slightly larger convection heights and, thus, with larger aspect ratios.The scene-averaged brightness temperature of AVHRR channel 4 exhibits a definite correlation with the sea-air temperature difference and,less well expressed, with the sensible and latent heat flux. This, in turn, provides a possibility of estimating those quantities by using easily accessible AVHRR satellite data.

show abstract

Wind shear at tilted inversions

Brümmer

1991

Boundary-Layer Meteorol

Self Cite

View full text Add to dashboard Cite

Vertical wind shear at a temperature inversion can be caused by baroclinicity associated with a tilt of the inversion. Four observational cases of tilted inversions are presented. The tilts on horizontal scales of 20-100 km range from 2-10 x 10m3 and the vertical wind shear is between 1 and 25 m/s per 100 m. In general, there is remarkable agreement between observed and geostrophic wind shear.The observations show that the inversion tilt is particularly strong at the edges of mesoscale cloud fields. The Richardson number can reach subcritical values. Cloud fields may be surrounded by a cyclonically rotating wind field and cloud gaps by an anticyclonically rotating wind field.

show abstract

Convective Patterns within a Field of Stratocumulus

Cited by 4 publications

References 0 publications

Mesoscale shallow convection in the atmosphere

Mesoscale shallow convection in the atmosphere

Cellular convection over the north‐eastern Atlantic

Wind shear at tilted inversions

Contact Info

Product

Resources

About