Inter-annual variability of ice nucleating particles in Mexico city
Por:
Cabrera-Segoviano, Diego, Pereira, Diana L., Rodriguez, Camila, Raga, Graciela B., Miranda, Javier, Alvarez-Ospina, Harry, Ladino, Luis A.
Publicada:
15 mar 2022
Resumen:
The continuous and sustained population shift from rural to urban areas
is driving most of the fast-growing megacities on a global scale.
Considerable pollution, gases and particulate matter, is emitted yearly
into the atmosphere of megacities, with unclear impacts on the local and
regional hydrological cycle. The present work evaluated the inter-annual
variability of super-micron (1.0-10 um) ice nucleating particles (INP),
via immersion freezing, sampled during the dry-warm season in Mexico
City on two consecutive years using the UNAM-MicroOrifice Uniform
Deposit Impactor-Droplet Freezing Technique (UNAM-MOUDI-DFT). The
aerosol particles emitted in Mexico City were found to act as INP via
the immersion freezing mode at temperatures below -20 degrees C with INP
concentrations ranging between 0.74 L-1 (-20 degrees C) and 20.42 L-1
(-30 degrees C). Although the INP concentration varied between the
dry-warm seasons, the average concentrations between 2018 and 2019 were
rather similar, with significant differences only observed at -20
degrees C. The large increase (>200%) in fine particulate matter -PM2.5
- observed during the 2019 severe air pollution episode caused by
biomass burning (BB) emissions, did not impact the super-micron INP
concentrations between -20 degrees C and -30 degrees C. However, INPs at
temperatures above -15 degrees C were found to increase during the
severe pollution episode. Given that such warm ice nucleation
temperatures can be linked with the presence of biological particles,
the present observations suggest that the BB plumes transported into
Mexico City were most likely advecting co-emitted biological particles.
Filiaciones:
Cabrera-Segoviano, Diego:
Instituto de Ciencias de la Atmósfera y Cambio Climático, Universidad Nacional Autónoma de México, Mexico City, Mexico
Univ Nacl Autonoma Mex, Inst Ciencias Atmosfera & Cambio Climat, Mexico City, Mexico
Pereira, Diana L.:
Instituto de Ciencias de la Atmósfera y Cambio Climático, Universidad Nacional Autónoma de México, Mexico City, Mexico
Univ Nacl Autonoma Mex, Inst Ciencias Atmosfera & Cambio Climat, Mexico City, Mexico
Rodriguez, Camila:
Instituto de Ciencias de la Atmósfera y Cambio Climático, Universidad Nacional Autónoma de México, Mexico City, Mexico
Univ Nacl Autonoma Mex, Inst Ciencias Atmosfera & Cambio Climat, Mexico City, Mexico
Raga, Graciela B.:
Instituto de Ciencias de la Atmósfera y Cambio Climático, Universidad Nacional Autónoma de México, Mexico City, Mexico
Univ Nacl Autonoma Mex, Inst Ciencias Atmosfera & Cambio Climat, Mexico City, Mexico
Miranda, Javier:
Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Mexico City, Mexico
Univ Nacl Autonoma Mex, Inst Fis, Mexico City, Mexico
Alvarez-Ospina, Harry:
Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
Univ Nacl Autonoma Mex, Fac Ciencias, Mexico City, Mexico
Ladino, Luis A.:
Instituto de Ciencias de la Atmósfera y Cambio Climático, Universidad Nacional Autónoma de México, Mexico City, Mexico
Univ Nacl Autonoma Mex, Inst Ciencias Atmosfera & Cambio Climat, Mexico City, Mexico
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