Περίληψη:
This study introduces an Earth observation (EO)-based system which is
capable of operationally estimating and continuously monitoring the
ultraviolet index (UVI) in Europe. UVIOS (i.e., UV-Index Operating
System) exploits a synergy of radiative transfer models with
high-performance computing and EO data from satellites (Meteosat Second
Generation and Meteorological Operational Satellite-B) and retrieval
processes (Tropospheric Emission Monitoring Internet Service, Copernicus
Atmosphere Monitoring Service and the Global Land Service). It provides
a near-real-time nowcasting and short-term forecasting service for UV
radiation over Europe. The main atmospheric inputs for the UVI
simulations include ozone, clouds and aerosols, while the impacts of
ground elevation and surface albedo are also taken into account. The
UVIOS output is the UVI at high spatial and temporal resolution (5 km
and 15 min, respectively) for Europe (i.e., 1.5 million pixels) in real
time. The UVI is empirically related to biologically important UV dose
rates, and the reliability of this EO-based solution was verified
against ground-based measurements from 17 stations across Europe.
Stations are equipped with spectral, broadband or multi-filter
instruments and cover a range of topographic and atmospheric conditions.
A period of over 1 year of forecasted 15 min retrievals under all-sky
conditions was compared with the ground-based measurements. UVIOS
forecasts were within +/- 0.5 of the measured UVI for at least 70 % of
the data compared at all stations. For clear-sky conditions the
agreement was better than 0.5 UVI for 80 % of the data. A sensitivity
analysis of EO inputs and UVIOS outputs was performed in order to
quantify the level of uncertainty in the derived products and to
identify the covariance between the accuracy of the output and the
spatial and temporal resolution and the quality of the inputs. Overall,
UVIOS slightly overestimated the UVI due to observational uncertainties
in inputs of cloud and aerosol. This service will hopefully contribute
to EO capabilities and will assist the provision of operational early
warning systems that will help raise awareness among European Union
citizens of the health implications of high UVI doses.
Συγγραφείς:
Kosmopoulos, Panagiotis G.
Kazadzis, Stelios
Schmalwieser, Alois
W.
Raptis, I, Panagiotis
Papachristopoulou, Kyriakoula and
Fountoulakis, Ilias
Masoom, Akriti
Bais, Alkiviadis F. and
Bilbao, Julia
Blumthaler, Mario
Kreuter, Axel
Siani, Anna
Maria
Eleftheratos, Kostas
Topaloglou, Chrysanthi
Groebner,
Julian
Johnsen, Bjorn
Svendby, Tove M.
Vilaplana, Jose
Manuel
Doppler, Lionel
Webb, Ann R.
Khazova, Marina
De
Backer, Hugo
Heikkila, Anu
Lakkala, Kaisa
Jaroslawski,
Janusz
Meleti, Charikleia
Diemoz, Henri
Huelsen, Gregor and
Klotz, Barbara
Rimmer, John
Kontoes, Charalampos
