Total flash density and the intracloud/cloud‐to‐ground lightning ratio over the Iberian Peninsula

Abstract

[1] Analysis of the total, intracloud and cloud-to-ground lightning flash density and the intracloud (IC) to cloud-to-ground (CG) ratio (Z = IC/CG) over the Iberian Peninsula (IP) has been performed using 5 years of combined data from the Spanish lightning detection network and the NASA Optical Transient Detector (OTD). The spatial distributions of total flash density and CG flash density show significant differences, especially on the northwest of the IP, the southern island of the Balearic Islands, and the southern/southeastern Mediterranean coastline. The spatial average of the annual value of Z is 3.48. A correlation was found between Z and latitude (correlation coefficient: À0.9). A relationship between Z and the total flash density was also observed (Z $ f 0.5 ; correlation coefficient: 0.48). The spatial pattern of Z is reminiscent of that of the percentage of positive CG-flashes, and high Z values seem to occur where the percentage of positive flashes is high.Citation: Soriano, L. R., and F. de Pablo (2007), Total flash density and the intracloud/cloud-to-ground lightning ratio over the Iberian Peninsula,

Lightning NO x and Impacts on Air Quality

“…Ground-based networks provide real-time coverage of lightning location and some physical properties (e.g., polarity, peak current) in many countries, and research arrays record comprehensive 4-D lightning physics at many sites. Most lightning flashes are inter-or intra-cloud (IC) rather than cloud-to-ground (CG) [125], although there is large spatial and temporal variability in the exact ratio [17,74,95,120,132,171], with possible implications for lightning-NO production and chemistry in the boundary layer. However, flash rate parameterizations in global models generally show low skill in reproducing the lightning distribution unless adjusted to the satellite observations; those parameterized upon mixed-phase particle collisions or cloud-ice flux perform the best [38,61,101,162].…”

Types of lightning discharges that abruptly terminate enhanced fluxes of energetic radiation and particles observed at ground level

“…Lightning flashes can be grouped into two categories: those striking the ground and those not doing so. The intracloud to cloud‐to‐ground lightning flash ratio has been extensively studied in many regions all over the world [e.g., Pierce , ; Prentice and Mackerras , ; MacGorman et al ., ; Boccippio et al ., ; Orville et al ., ; Soriano and de Pablo , ; Kuleshov et al ., ; de Souza et al ., ]. It is generally believed that intracloud, intercloud, and cloud‐to‐air flashes (all of which do not involve ground) comprise around 70–75% of lightning discharges, and that cloud‐to‐ground flashes comprise 25–30%.…”

The global lightning-induced nitrogen oxides source

“…Most studies suggest a global annual mean IC/CG flash ratio f IC /f CG of about 2 to 4, see Table 9. The ratio increases with the total flash density (Soriano and de Pablo, 2007), with values exceeding 50 in intensive individual storms Thery, 2001;Wiens et al, 2005). A latitudinal dependence of the IC/CG flash ratio has been suggested in many studies (Pierce, 1970;Prentice and MacKerras, 1977).…”

“…The amount of convective available potential energy (CAPE) is similar over land and oceans. However oceanic updrafts achieve a Soriano and de Pablo (2007) lower fraction of their potentially available updraft velocities because of higher water loading (reducing buoyancy), more lateral entrainment, less buoyancy at low levels (Lucas et al, 1994a), and lower cloud base (Lucas et al, 1994b;Mushtak et al, 2005;Williams et al, 2005). The higher cloud base over land correlates with larger scales in the boundary layer, wider updrafts, less entrainment, and larger ice content above the freezing level (Lucas et al, 1994b;Zipser and Lutz, 1994;Williams and Stanfill, 2002).…”