@conference{González2021bb,
title = {Monitoring of long-range transported smoke in polar regions with remote sensing instruments},
author = {R. González and C. Toledano and R. Román Diez and D. Mateos and E. Asmi and E. Rodriguez and J.C. Antuña-Sánchez and S. Herrero-Anta and V.E. Cachorro and A. Calle and A.M. de Frutos},
year = {2021},
date = {2021-04-29},
booktitle = {EGU21},
address = {Online},
organization = {European Geosciences Union (EGU)},
abstract = {Long range transported aerosol from biomass burning affects polar regions, especially the Arctic. The frequency and intensity of bushfires in the context of a warming climate has been pointed out in the last report of the Intergovernmental Panel on Climate Change. In high latitudes, these events impact large areas through long-range transport of the smoke particles in the troposphere or even the stratosphere. The lifetime and radiative impact are related with the height of the plumes and the processes that modify particle size and absorptive properties during the transport. Several recent publications have shown the impact of the Australian smoke in the southern hemisphere, including Antarctica, in January-March 2020. The tools that were used to monitor that extraordinary event can be used in the Arctic to investigate similar effects in the frequent biomass burning events that generate smoke plumes in boreal regions. In this work, we present the results derived from ground-based instrumentation as well as satellite and model data. The change of the smoke properties after several days of transport is also provided, namely an increase in the fine mode particle size and the single scattering albedo, as well as a decrease in the coarse mode particle concentration. These features are relevant for radiative forcing calculations and therefore the impact of long range transported smoke in the radiative balance over polar regions.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}

@conference{Herrero-Anta2021b,
title = {Inventory of aerosol episodes in Ny-Ålesund (Svalbard) in the period 2017-2020 by sun photometry},
author = { S. Herrero-Anta and D. Mateos and C. Toledano and R. Román and R. González and C. Ritter and J.C. Antuña-Sanchez and D. González-Fernández and A. Calle and V.E. Cachorro and A.M. de Frutos},
year = {2021},
date = {2021-04-29},
booktitle = {EGU21},
address = {Online},
organization = {European Geosciences Union (EGU)},
abstract = {Atmospheric aerosols are an important forcing agent in the estimation of radiative budget, being the Arctic an area of special weakness. The Group of Atmospheric Optics, University of Valladolid and the Alfred Wegener Institute for Polar and Marine Research, installed in 2017 a CE-318T Sun-sky-Moon photometer (Cimel Electronique S.A.S) in the Arctic station Ny-Ålesund (79ºN, 12ºE). This study presents an inventory of all high-turbidity aerosol episodes recorded in the period 2017-2020 (data of level 1.5-validated from AERONET). This inventory is based on the separate analysis of coarse and fine mode aerosol optical depth. Aerosol episodes are attributed to coarse, fine or mixture of aerosols. Complementary information provided by HYSPLIT air mass back trajectories, MODIS images, forecast aerosol models, CALIOP/CALIPSO satellite data, and other collocated instruments on the station are also used. Special focus is given to long-range transport of aerosols from big forest fires in Canada, United States and Russia},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}

@conference{Taylor2021,
title = {LIME: the Lunar Irradiance Model of the European Space Agency},
author = {S. Taylor and S. Adriaensen and C. Toledano and A. Barreto and E. Woolliams and M. Bouvet},
year = {2021},
date = {2021-04-29},
booktitle = {EGU21},
address = {Online},
organization = {European Geosciences Union (EGU)},
abstract = {Absolute calibration of Earth observation sensors is key to ensuring long term stability and interoperability, essential for long term global climate records and forecasts. The Moon provides a photometrically stable calibration source, within the range of the Earth radiometric levels, and is free from atmospheric interference. However, to use this ideal calibration source, one must model the variation of its disk integrated irradiance resulting from changes in Sun-Earth-Moon geometries.

LIME, the Lunar Irradiance Model of the European Space Agency, is a new lunar irradiance model developed from ground-based observations acquired using a lunar photometer operating from the Izaña Atmospheric Observatory and Teide Peak, Tenerife. Approximately 300 lunar observations acquired between March 2018 and October 2020 currently contribute to the model, which builds on the widely-used ROLO (Robotic Lunar Observatory) model.

This presentation will outline the strategy used to derive LIME. First, the instrument was calibrated traceably to SI and characterised to determine its thermal sensitivity and its linearity over the wide dynamic range required. Second, the instrument was installed at the observatory, and nightly observations over a two-hour time window were extrapolated to provide top-of-atmosphere lunar irradiance using the Langley plot method. Third, these observations were combined to derive the model. Each of these steps includes a metrologically rigorous uncertainty analysis.

Comparisons to several EO sensors will be presented including Proba-V, Pleiades and Sentinel 3A and 3B, as well as a comparison to GIRO, the GSICS implementation of the ROLO model. Initial results indicate LIME predicts 3% - 5% higher disk integrated lunar irradiance than the GIRO/ROLO model for the visible and near-infrared channels. The model has an expanded (k = 2) absolute radiometric uncertainty of ~2%, and it is expected that planned observations until at least 2024 will further constrain the model in subsequent updates.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}

@conference{Herrero-Anta2021,
title = {Long range transported aerosol events over Ny-Alesund (Svalbard) in 2020 observed with Sun-Sky-Moon photometry},
author = {S. Herrero-Anta and C. Toledano and R. Román and R. González and C. Rtitter and J.C. Antuña-Sánchez and D. González-Fernández and A. Calle and V.E. Cachorro and A.M. de Frutos},
year = {2021},
date = {2021-03-26},
booktitle = {Arctic Science Summit Week 2021 (ASSW2021)},
address = {Lisbon, Portugal (online)},
organization = {International Arctic Science Committee (IASC)},
abstract = {The recent development of the of Sun-sky-Moon photometers allows using both Sun and Moon as light sources to retrieve columnar aerosol properties. In this framework, the Group of Atmospheric optics, University of Valladolid and the Alfred Wegener Institute for Polar and Marine Research, installed in 2017 a CE-318T Sun-sky-Moon photometer (Cimel Electronique S.A.S) in the Arctic station Ny-Ålesund (79oN, 12oE). This instrument contributes to the AErosol RObotic NETwork (AERONET), and it is recording a continuous (summer +winter) database of columnar aerosol properties. This study presents an inventory of all high-turbidity aerosol episodes recorded in 2020 based on the mentioned photometer measurements. Complementary information provided by HYSPLIT air mass back trajectories, MODIS images, forecast aerosol models, CALIOP/CALIPSO satellite data, and other collocated instruments on the station are also used. Special focus is given to long-range transport of aerosols from forest fires in Canada, United States and Russia.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}