16065 research outputs found
Sort by
Global ground-based tropospheric ozone measurements: reference data and individual site trends (2000–2022) from the TOAR-II/HEGIFTOM project
No full textTropospheric ozone trends from models and satellites are found to diverge. Ground-based (GB) observations are used to reference models and satellites, but GB data themselves might display station biases and
discontinuities. Reprocessing with uniform procedures, the TOAR-II working group Harmonization and Evaluation of Ground-based Instruments for Free-Tropospheric Ozone Measurements (HEGIFTOM) homogenized
public data from five networks: ozonesondes, In-service Aircraft for a Global Observing System (IAGOS) profiles, solar absorption Fourier transform infrared (FTIR) spectrometer measurements, lidar observations, and
Dobson Umkehr data. Amounts and uncertainties for total tropospheric ozone (TrOC; surface to 300 hPa), as
well as free- and lower-tropospheric ozone, are calculated for each network. We report trends (2000 to 2022)
for these segments using quantile regression (QR) and multiple linear regression (MLR) for 55 datasets, including six multi-instrument stations. The findings are that (1) median TrOC trends computed with QR and MLR
trends are essentially the same; (2) pole-to-pole, across all longitudes, TrOC trends fall within +3 to −3 ppbv
per decade, equivalent to (−4 % to +8 %) per decade depending on site; (3) the greatest fractional increases
occur over most tropical and subtropical sites, with decreases at northern high latitudes, but these patterns are
not uniform; (4) post-COVID trends are smaller than pre-COVID trends for Northern Hemisphere mid-latitude
sites. In summary, this analysis conducted in the frame of TOAR-II/HEGIFTOM shows that high-quality, multiinstrument, harmonized data over a wide range of ground sites provide clear standard references for TOAR-II
models and evolving tropospheric ozone satellite products for 2000–2022
Celebración de los resultados favorables en el fomento de la colaboración y la coordinación a escala regional: perspectivas de la Asociación Regional V
No full textBalance hídrico nacional. Número 22/2025
No full textBalance hídrico correspondiente al 10 de agosto de 2025
Balance hídrico nacional. Número 32/2025
No full textBalance hídrico correspondiente al 20 de noviembre de 2025
