1
General Characteristics
of the Atmospheric Boundary Layer
Abstract
This chapter includes a general characterization of the atmospheric boundary
layer with an analysis of micro, macro, and synoptic atmospheric scales in the
troposphere. The dimensional scales and frequencies of average flow, turbulence, and atmospheric waves are discussed in relation to the transport of scalar
and vector variables. The conditions of atmospheric stability and instability,
associated with the vertical adiabatic gradient of actual and potential temperatures with daily variation of the structure of the atmospheric boundary layer,
were evaluated. The dynamics of atmospheric boundary layers, top inversion,
mixed layer, and surface layers along with subsidence and divergency play a
significant role as discussed.
About 80% of the atmosphere mass is in the troposphere. This layer extends from
the Earth’s surface up to an average altitude of 11 km and is characterized by a
vertical decreasing of temperature with an average gradient of 0.65 °C/100 m.
The atmospheric boundary layer is defined as part of the troposphere that is
directly influenced by the Earth’s surface and responds to surface perturbations
within a timescale of an hour or less (Stull 1994). Some of these perturbations
include frictional drag, evapotranspiration, and heat transfer by convection, pollutant emission, and flux changes brought about by surface topographical changes.
The thickness of the atmosphere’s boundary layer varies over time and space,
ranging from hundreds of meters up to one or two kilometers.
Atmospheric motion occurs in scales that vary a great deal (Stull 2000). The size
classes usually described are turbulence in the range of 2–200 mm, the constant
flux layer that ranges from 200 mm to 200 m, the atmospheric boundary layer up to
about 1000–1500 m, the mesoscale dimensions comprising up to 2000 km, the
synoptic scale comprising movements of air masses between 2000 and 15,000 km
and finally, movements on a planetary scale that extend to heights of about
15,000 km.
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
A. Rodrigues et al., Fundamental Principles of Environmental Physics,
https://doi.org/10.1007/978-3-030-69025-0_1
1
General Characteristics
of the Atmospheric Boundary Layer
Abstract
This chapter includes a general characterization of the atmospheric boundary
layer with an analysis of micro, macro, and synoptic atmospheric scales in the
troposphere. The dimensional scales and frequencies of average flow, turbulence, and atmospheric waves are discussed in relation to the transport of scalar
and vector variables. The conditions of atmospheric stability and instability,
associated with the vertical adiabatic gradient of actual and potential temperatures with daily variation of the structure of the atmospheric boundary layer,
were evaluated. The dynamics of atmospheric boundary layers, top inversion,
mixed layer, and surface layers along with subsidence and divergency play a
significant role as discussed.
About 80% of the atmosphere mass is in the troposphere. This layer extends from
the Earth’s surface up to an average altitude of 11 km and is characterized by a
vertical decreasing of temperature with an average gradient of 0.65 °C/100 m.
The atmospheric boundary layer is defined as part of the troposphere that is
directly influenced by the Earth’s surface and responds to surface perturbations
within a timescale of an hour or less (Stull 1994). Some of these perturbations
include frictional drag, evapotranspiration, and heat transfer by convection, pollutant emission, and flux changes brought about by surface topographical changes.
The thickness of the atmosphere’s boundary layer varies over time and space,
ranging from hundreds of meters up to one or two kilometers.
Atmospheric motion occurs in scales that vary a great deal (Stull 2000). The size
classes usually described are turbulence in the range of 2–200 mm, the constant
flux layer that ranges from 200 mm to 200 m, the atmospheric boundary layer up to
about 1000–1500 m, the mesoscale dimensions comprising up to 2000 km, the
synoptic scale comprising movements of air masses between 2000 and 15,000 km
and finally, movements on a planetary scale that extend to heights of about
15,000 km.
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
A. Rodrigues et al., Fundamental Principles of Environmental Physics,
https://doi.org/10.1007/978-3-030-69025-0_1
1