On the role of thermodynamics and cloud-aerosol-precipitation interactions over thunderstorm activity during GoAmazon and ACRIDICON-CHUVA field experiments

Tuesday, 15 December 2015: 16:30
3008 (Moscone West)
Rachel I Albrecht1, Carlos A. Morales1, Hartmut Hoeller2, Ramon C. Braga3, Luiz Machado4, Manfred Wendisch5, Meinrat O Andreae6, Daniel Rosenfeld7, Ulrich Poeschl6, Thiago Biscaro4, Wagner Lima4, Cristiano Eichholz4, Romulo Augusto Juca Oliveira8, Vinicius Sperling3, Izabelly Carvalho3, Alan James P Calheiros3, Lia F Amaral3, Micael Cecchin4, Jaci Saraiva9, Ivan Saraiva9, Courtney Schumacher10 and Aaron Brandon Funk11, (1)Universidade de São Paulo, São Paulo, Brazil, (2)German Aerospace Center DLR Oberpfaffenhofen, Oberpfaffenhofen, Germany, (3)INPE National Institute for Space Research, CPTEC, Cachoeira Paulista, Brazil, (4)INPE National Institute for Space Research, Sao Jose dos Campos, Brazil, (5)University of Leipzig, Leipzig Institute for Meteorology, Leipzig, Germany, (6)Max Planck Institute for Chemistry, Mainz, Germany, (7)Hebrew University of Jerusalem, Jerusalem, Israel, (8)National Institute for Space Research (INPE), Cachoeira Paulista, Brazil, (9)Sistema de Proteção da Amazônia, Manaus, Brazil, (10)Texas A & M University College Station, College Station, TX, United States, (11)Texas A&M Univ, College Station, TX, United States
Based on satellite data, total (intracloud and cloud-to-ground) lightning activity climatological annual cycle over the GoAmazon area of interest (from T0 to T3 sites) shows that lightning activity is moderate (up to 10 flashes per day – fl day-1) throughout the wet (December-March) and dry (April-August) seasons, with T3 always being a little greater than T1 and T0 sites, respectively. During the dry-to-wet transition season (September-October), however, lightning activity peaks up to 25 fl day-1 at T1, followed by T3 (20 fl day-1) and T0 (15 fl day-1). The diurnal cycle reveals that the onset of deep convection during this same season starts one hour and peaks two hours earlier than the wet season. In the Amazon, cloud updrafts are primarily controlled by the local environment thermodynamics. During the dry-to-wet transition season, thermodynamics is significantly changed by land cover land cover where cloud base heights are elevated over deforested areas potentially increasing the strength of updrafts due to a better processing of the convective available potential energy, and therefore also increasing cloud electrification. The total (intracloud and cloud-to-ground) LIghtning NET(LINET - Nowcast) installed in September-October 2014 for GoAmazon IOP2 and ACRIDICON-CHUVA field experiments and the set of weather radars revealed that the thunderstorm enhancement over T1 (Manaus) during the dry-to-wet season is driven by the interaction between river breeze and the main easterly winds over Amazon basin, resulting in a locally forced convergent flow on the east side of Rio Negro which drives deep afternoon convection. In terms of atmospheric pollution, the dry-to-wet season is also marked by increased biomass burning, and the city of Manaus (T1) is a local polluted heat island. We will also present quantified thermodynamical and microphysical differences between the thunderstorms that developed over T0, T1 and T2. Our hypothesis is that cloud charge centers, total lightning activity and retrieved microphysics from radar and aircraft measurements (G-1 and HALO) will simultaneously show the influence of the shift from warm- to mixed-phase dominated microphysics caused by aerosol and thermodynamic variability.