Toward a New UV Index Diagnostic in the Met Office's Forecast Model

Abstract

The United Kingdom sporadically experiences low ozone events in the spring which can increase UV to harmful levels and is particularly dangerous as sunburn is not expected by the public at this time of year. This study investigates the benefits to the UV Index diagnostic produced by the UM at the Met Office of including either, or both of, a more highly resolved spectrum, and forecasted ozone profiles from the ECMWF CAMS database. Two new configurations of the spectral parameters governing the radiative transfer calculation over the UV region are formulated using the correlated‐k method to give surface fluxes that are within 0.1 UV Index of an accurate reference scheme. Clear‐sky comparisons of modeled fluxes with ground‐based spectral observations at two UK sites (Reading and Chilton) between 2011 and 2015 show that when raw CAMS ozone profiles are included noontime UV indices are always overestimated, by up to 3 UV indices at a low ozone event and up to 1.5 on a clear summer day, suggesting CAMS ozone concentrations are too low. The new spectral parameterizations reduce UV Index biases, apart from when combined with ozone profiles that are significantly underestimated. When the same biases are examined spectrally across the UV region some low biases on low ozone days are found to be the result of compensating errors in different parts of the spectrum. Aerosols are postulated to be an additional source of error if their actual concentrations are higher than those modeled.

NASA GEOS Composition Forecast Modeling System GEOS‐CF v1.0: Stratospheric Composition

“…Ozone (O 3 ) is an important trace gas in the stratosphere where the total O 3 column acts to shield the Earth's surface from harmful ultra‐violet (UV) radiation, while at the surface it is harmful to human health and vegetation (Krzyzanowski & Cohen, 2008 ; Schlink et al., 2006 ). Since the total column O 3 (TCO) varies from day‐to‐day depending on stratospheric conditions, forecasting TCO is an important input for accurate surface UV forecasts (Turner et al., 2017 ). The discovery of the Antarctic “Ozone hole” nearly 40 years ago by ground‐based, sonde and satellite measurements (e.g., Farman et al., 1985 ; Solomon et al., 1986 ; Stolarski et al., 1986 ) indicated decreases in the ozone layer were greater than the 1% per decade that early models were predicting (Bhartia & McPeters, 2018 ).…”

Optimization algorithms as training approach with hybrid deep learning methods to develop an ultraviolet index forecasting model

“…However, the research on UV radiation has also been a serious concern due to its dichotomous nature. UV irradiance can also have detrimental biological effects on human health, such as skin cancer and eye disease (Lucas et al 2008 ; Turner et al 2017 ). Chronic exposure to UV light has been reported as a significant risk factor responsible for melanoma and non-melanoma cancers (Saraiya et al 2004 ; Sivamani et al 2009 ) and is associated with 50–90% of these diseases.…”

Optimization Algorithms As Training Approach With Deep Learning Methods To Develop An Ultraviolet Index Forecasting Model

“…However, the research on UV radiation has also been a serious concern over the years due to its dichotomy nature. UV irradiance can also have detrimental biological effects on human health, such as skin cancer and eye disease (Lucas et al, 2008;Turner et al, 2017). Chronic exposure to UV light has been reported as a major risk factor responsible for melanoma and nonmelanoma cancers (Saraiya et al, 2004;Sivamani et al, 2009) and associated with 50-90% of these diseases.…”