A Satellite‐Based Estimate of Convective Vertical Velocity and Convective Mass Flux: Global Survey and Comparison With Radar Wind Profiler Observations

Abstract

Convection is fundamental to atmospheric energetics and general circulation. While the ultimate energy source for Earth's atmosphere comes from the Sun, most of the solar insolation is directly deposited at the surface. Convection redistributes the energy by transporting it from the surface upward into the atmosphere, balancing atmospheric cooling in the infrared, and driving large-scale circulation (e.g., Hartmann, 2016). In doing so, convection also moves momentum, moisture, and chemically important trace constituents from the planetary boundary layer to the free troposphere. Deep convection can even communicate these influences all the way to the upper troposphere and lower stratosphere (e.g., Fueglistaler et al., 2009). For these reasons, properly representing convection and convective transport has always been a central task of the global climate models (GCMs) (e.g., Arakawa, 2004).

Convective Mass‐Flux From Long Term Radar Reflectivities Over Darwin, Australia

“…This choice results in constant profiles of area fraction up to 9 km, thus strongly influencing the results obtained when analyzing the vertical derivatives of mass-flux and its components. The dominant role of convective area fraction in determining mass-flux was suggested in several other studies (e.g., Jeyaratnam et al, 2021;Kumar et al, 2015;Masunaga & Luo, 2016) including LES experiments (e.g., Böing et al, 2012;de Rooy & Siebesma, 2010) and it is confirmed in our study. These results encourage parameterization methods that aim to estimate area fraction and vertical velocity separately (de Rooy & Siebesma, 2010;Peters et al, 2013Peters et al, , 2017Siebesma et al, 2020).…”

“…10.1029/2021JD034910 13 of 17 in determining mass-flux was suggested in several other studies (e.g., Jeyaratnam et al, 2021;Kumar et al, 2015;Masunaga & Luo, 2016) including LES experiments (e.g., Böing et al, 2012;de Rooy & Siebesma, 2010) and it is confirmed in our study. These results encourage parameterization methods that aim to estimate area fraction and vertical velocity separately (de Rooy & Siebesma, 2010;Peters et al, 2013Peters et al, , 2017Siebesma et al, 2020).…”

“…Similarly, for the Amazon basin, Giangrande et al (2016) considered 1, 3, and 6-hr intervals that featured a minimum 1% convective area fraction. Another recent study from Jeyaratnam et al (2021), and based on satellite measurements, showed similar large magnitudes of area fraction as a result of the same 3-hr averaging method. Their choice reflects conditions on longer time scales compared to our 10 min scale.…”

“…Another recent study from Jeyaratnam et al. (2021), and based on satellite measurements, showed similar large magnitudes of area fraction as a result of the same 3‐hr averaging method. Their choice reflects conditions on longer time scales compared to our 10 min scale.…”

Convective Updraft and Downdraft Characteristics of Continental Mesoscale Convective Systems in the Model Gray Zone

“…The observations in Figures 11f and 11l show that the most intense convective updrafts and downdrafts are within the deeper convective cores. This is not surprising and it is consistent with previous observational findings (e.g., Jeyaratnam et al., 2021). Peak values of updraft and downdraft velocities appear in the highest ETH bin, reaching 23.5 m/s and −15.7 m/s, respectively.…”