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Geostationary Satellites Total Ozone Observations: First Results on Ground‐Based Networks Validation Efforts for TEMPO and GEMS
No full textThe Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument, launched in April 2023, is North America's first geostationary air pollution monitoring satellite mission. Together with Asia's Geostationary Environment Monitoring Spectrometer (GEMS) launched in 2020 and Europe's upcoming Sentinel-4, TEMPO contributes to nearly global coverage provided by geostationary satellite constellation. TEMPO and GEMS offer hourly, high-resolution data of ozone surpassing the once-daily observations of instruments like the TROPOspheric Monitoring Instrument (TROPOMI) in temporal resolution. This study presents TEMPO's total ozone data, demonstrating TEMPO's ability to observe sudden changes in ozone and UV index. Furthermore, TEMPO and GEMS measurements are validated using ground-based monitoring networks (Brewer, Dobson, and Pandora). Results show good agreement but also highlight latitude-dependent discrepancies between the satellite and ground-based data sets (−2% to 2% for TEMPO, −1% to −3% for GEMS). Findings are further validated using TROPOMI data and reanalysis models.Irina Petropavlovskikh's research was supported by a NOAA Cooperative Agreement with CIRES, NA17OAR4320101. The Mexican Pandora instruments and operation were financed through Grants by AEM-CONAHCYT (275239) and UNAM-DGAPA (IG101225). SAO coauthors were supported by the NASA TEMPO project (Contract NNL13AA09C), as well as the NASA Grant 80NSSC19K1626. We thank Dr. Peter Effertz at CIRES, University of Colorado, for generating temperature-corrected Dobson data for the U.S. sites
Caracterización de las zonas susceptibles a aludes en la sierra de Guadarrama mediante el modelo Gravitational Process Path
No full textEn el presente trabajo se muestran los resultados que se han obtenido al estimar las zonas
potenciales de salida y de recorrido de aludes en la sierra de Guadarrama utilizando el modelo
Gravitational Process Path. El modelo se calibró a partir de un detallado registro histórico de aludes
observados en la zona de estudio, y se aplicó utilizando un modelo digital de elevaciones y un
modelo de vegetación de alta resolución para estimar las áreas propensas a aludes en zonas
cercanas donde no existe un registro detallado de avalanchas de nieve. Finalmente, se realizó una
validación de los resultados obtenidos comparándolos con los aludes observados,
comprobándose la validez del modelo para estimar las zonas propensas a las avalanchas de nieve
en zonas donde no se dispone de una información exhaustiva de la ocurrencia de aludes
Defining medicanes: bridging the nowledge gap between tropical and extratropical cyclones in the Mediterranean
No full textThis article is the outcome of the community building within the framework of
the COST Action CA19109 “MedCyclones” supported by COST–European Cooperation in Science
and Technology. All authors are thus acknowledged for their participation and exchanges on the
matter. This work was partly supported by the European Space Agency through the CYMS project
(Contract No.4000129822/19/I-DT - https://www.esa-cyms.org/), “Earth Observations as a
cornerstone to the understanding and prediction of tropical like cyclone risk in the Mediterranean
(MEDICANES)”, ESA Contract No. 4000144111/23/I-KE. MMM acknowledges financial support
from Next Generation EU, Mission 4, Component 1, CUP B53D23007360006, project “WIND
RISK”. JJGA thanks support from AEMET and from the Spanish PID2023-146344OB-I00 project,
funded by MICIU/AEI/10.13039/501100011033 and by FEDER, EU. This work was made possible
by the TROPICANA program of the Institut Pascal at Université Paris-Saclay with the support of
the program "Investissements d'avenir" ANR-11-IDEX-0003-01; interesting discussions with Kerry
Emanuel (MIT) and all people involved in the first week of TROPICANA programme influenced
the eventual direction of the manuscript.The term “Mediterranean tropical-like cyclone” or “medicane” has been used in different ways by different authors. Identification of medicanes has been based on features observed from satellite imagery or on diagnostics applied to numerical weather prediction model outputs. In the absence of an official definition, medicanes are generally considered to be cyclones over the Mediterranean sharing physical processes with tropical cyclones. Nevertheless, recent studies on the dynamics of several systems widely recognized as medicanes show different underlying development mechanisms. A commonly agreed definition is critical and necessary to assess their climatology in past and future climates, as well as to consistently identify such systems in weather forecasts. The scientific community working on Mediterranean cyclones hereby proposes a definition, which is based solely on Earth observations: “A medicane is a mesoscale cyclone that develops over the Mediterranean Sea and displays tropical-like cyclone characteristics: a warm core extending into the upper troposphere, an eye-like feature in its center with spiral cloud bands around, an almost windless center surrounded by nearly-symmetric sea-surface wind circulation with maximum wind speed within a few tens of km from the center.
Balance hídrico nacional. Número 23/2025
No full textBalance hídrico correspondiente al 20 de agosto de 2025
Ground-based tropospheric ozone measurements: regional tropospheric ozone column trends from the TOAR-II/HEGIFTOM homogenized datasets
No full textQuantifying long-term free-tropospheric ozone trends is essential for understanding the impact of human activities and climate change on atmospheric chemistry. However, this is complicated by two key challenges: the differences among existing satellite-derived tropospheric ozone products, which are not yet fully understood or reconciled, and the limited temporal and spatial coverage of ground-based reference measurements. Here, we explore if a more consistent understanding of the geographical distribution of tropospheric ozone column (TrOC) trends can be obtained by focusing on regional trends from ground-based measurements. Regions were determined with a correlation analysis between modeled TrOCs at the site locations. For those regions, TrOC trends were estimated with quantile regression for the Trajectory-mapped Ozonesonde dataset for the Stratosphere and Troposphere (TOST) and with a linear mixed-effects modeling (LMM) approach to calculate synthesized trends from homogenized HEGIFTOM (Harmonization and Evaluation of Ground-based Instruments for Free-Tropospheric Ozone Measurements) individual site trends. For different periods (1990–2021/22, 1995–2021/22, 2000–2021/22), both approaches give increasing (partial) tropospheric ozone column amounts over almost all Asian regions (median confidence) and negative trends over Arctic regions (very high confidence). Trends over Europe and North America are mostly weakly positive (LMM) or negative (TOST). For both approaches, the 2000–2021/22 trends decreased in magnitude compared to 1995–2021/22 for most regions; and for all time periods and regions, the pre-COVID trends are larger than the post-COVID trends. Our results enable the validation of global satellite TrOC trends and assessment of the performance of atmospheric chemistry models to represent the distribution and variation of TrOC