Aerosol optical depth determination in the UV using a four-channel precision filter radiometer

Carlund, Thomas; Kouremeti, Natalia; Kazadzis, Stelios; Gröbner, Julian

doi:10.5194/amt-10-905-2017

Cited by 22 publications

(47 citation statements)

References 61 publications

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“…-calibration, which is the second largest contribution according to Carlund et al (2017), and which contributes u…”

Section: Brewer Aod Uncertaintymentioning

confidence: 99%

“…However, we will consider here a simplified model, taking into account only the three largest contributions found by Carlund et al (2017) to the total uncertainty in the 25 UV range for the UVPFR instrument, whose AOD algorithm shares similarities with that of the Brewer. We also assume no correlation between variables, and work within the approximation m a ≈ m o ≈ m R .…”

Section: Brewer Aod Uncertaintymentioning

confidence: 99%

“…A more elaborate term for the optical air mass could be used instead, like e.g. the average weighted by the optical depths proposed in Carlund et al (2017). However, we have found that in the atmospheric conditions of IZO and within the optical air 20 mass limits described below, switching from m o to m a produces differences of ∼ 0.01% in the calibration constants obtained from the Langley plot, so we don't expected any combination of the two air masses to introduce any significant changes.…”

Section: Aod Calibration Of Brewer Instrumentsmentioning

confidence: 99%

“…where each uncertainty u on the right hand side includes, if necessary, a factor 2 to translate from 1σ to 2σ level (GUM, 2008), -the ozone optical depth, which has been found by Carlund et al (2017) to be the largest contribution in the UV range for the UVPFR instrument. Ignoring the correlation between variables, the uncertainty of the ozone optical depth can be approximated by u…”

Section: Brewer Aod Uncertaintymentioning

confidence: 99%

“…Holben et al (1998);Dubovik et al (2000); Smirnov et al (2000). We use the highest quality data currently available for Cimel sunphotometers, the cloud-screened and quality-assured version 2 level 2.0 product downloaded from the AERONET more detailed information about the UVPFR, are described by Carlund et al (2017). Where necessary for our comparisons, the UVPFR data at the closest wavelengths to those of the Brewer have been interpolated using the Ångström relation.…”

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confidence: 99%

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Aerosol optical depth in the European Brewer Network

López-Solano¹,

Redondas²,

Carlund³

et al. 2017

Preprint

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Abstract. The high spatial and temporal variability of aerosols make networks capable of measuring their properties in near real time of high scientific interest. In this work we present and discuss results of an aerosol optical depth algorithm to be used in the European Brewer Network, which provides data in near real time of more than 30 spectrophotometers located from Tamanrasset (Algeria) to Kangerlussuaq (Greenland). Using data from the Brewer Intercomparison Campaigns in the years 2013 and 2015, and the period in between, plus comparisons with Cimel sunphotometers and UVPFR instruments, we check 5 the precision, stability, and uncertainty of the Brewer AOD in the ultraviolet range from 300 to 320 nm. Our results show a precision better than 0.01, an uncertainty of less than 0.05, and a stability similar to that of the ozone measurements for wellmaintained instruments. We also discuss future improvements to our algorithm with respect to the input data, their processing, and the characterization of the Brewer instruments for the measurement of aerosols.1 Atmos. Chem. Phys. Discuss., https://doi

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“…-calibration, which is the second largest contribution according to Carlund et al (2017), and which contributes u…”

Section: Brewer Aod Uncertaintymentioning

confidence: 99%

Section: Brewer Aod Uncertaintymentioning

confidence: 99%

Section: Aod Calibration Of Brewer Instrumentsmentioning

confidence: 99%

Section: Brewer Aod Uncertaintymentioning

confidence: 99%

mentioning

confidence: 99%

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Aerosol optical depth in the European Brewer Network

López-Solano¹,

Redondas²,

Carlund³

et al. 2017

Preprint

Self Cite

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A climatology of aerosol optical depths in the ultraviolet wavelengths for Hobart, Australia, as determined by a Brewer MKIII spectrophotometer

Núñez

Serrano

Larson³

2022

Intl Journal of Climatology

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The study examines aerosol optical depth (AOD) measurements at 320 nm wavelength by a Brewer MKIII spectrophotometer located in Hobart, Australia. A climatology was developed from records encompassing the period April 4, 2002, to February 27, 2019. A methodology is described to extract cloudless episodes and cloudless half-days. Extraterrestrial irradiances are obtained using a travelling calibration standard and are supplemented by Langley analyses on cloudless and stable half-days. AODs are obtained by applying Beer's law to every reading and subtracting known values of ozone optical depth and Rayleigh scatter. Statistics are provided on the daily, monthly and interannual variability. Concurrent measurements from a Multifilter Rotating Shadowband Radiometer (MFRSR) operating in the visible band enabled the spectral variability of AOD to be determined. They showed the dominance of oceanic aerosols but with some input from land-based aerosols originating mostly from biomass burning.

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Stratospheric ozone, UV radiation, and climate interactions

Bernhard

Bais

Aucamp³

et al. 2023

Photochem Photobiol Sci

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This assessment provides a comprehensive update of the effects of changes in stratospheric ozone and other factors (aerosols, surface reflectivity, solar activity, and climate) on the intensity of ultraviolet (UV) radiation at the Earth’s surface. The assessment is performed in the context of the Montreal Protocol on Substances that Deplete the Ozone Layer and its Amendments and Adjustments. Changes in UV radiation at low- and mid-latitudes (0–60°) during the last 25 years have generally been small (e.g., typically less than 4% per decade, increasing at some sites and decreasing at others) and were mostly driven by changes in cloud cover and atmospheric aerosol content, caused partly by climate change and partly by measures to control tropospheric pollution. Without the Montreal Protocol, erythemal (sunburning) UV irradiance at northern and southern latitudes of less than 50° would have increased by 10–20% between 1996 and 2020. For southern latitudes exceeding 50°, the UV Index (UVI) would have surged by between 25% (year-round at the southern tip of South America) and more than 100% (South Pole in spring). Variability of erythemal irradiance in Antarctica was very large during the last four years. In spring 2019, erythemal UV radiation was at the minimum of the historical (1991–2018) range at the South Pole, while near record-high values were observed in spring 2020, which were up to 80% above the historical mean. In the Arctic, some of the highest erythemal irradiances on record were measured in March and April 2020. For example in March 2020, the monthly average UVI over a site in the Canadian Arctic was up to 70% higher than the historical (2005–2019) average, often exceeding this mean by three standard deviations. Under the presumption that all countries will adhere to the Montreal Protocol in the future and that atmospheric aerosol concentrations remain constant, erythemal irradiance at mid-latitudes (30–60°) is projected to decrease between 2015 and 2090 by 2–5% in the north and by 4–6% in the south due to recovering ozone. Changes projected for the tropics are ≤ 3%. However, in industrial regions that are currently affected by air pollution, UV radiation will increase as measures to reduce air pollutants will gradually restore UV radiation intensities to those of a cleaner atmosphere. Since most substances controlled by the Montreal Protocol are also greenhouse gases, the phase-out of these substances may have avoided warming by 0.5–1.0 °C over mid-latitude regions of the continents, and by more than 1.0 °C in the Arctic; however, the uncertainty of these calculations is large. We also assess the effects of changes in stratospheric ozone on climate, focusing on the poleward shift of climate zones, and discuss the role of the small Antarctic ozone hole in 2019 on the devastating “Black Summer” fires in Australia. Additional topics include the assessment of advances in measuring and modeling of UV radiation; methods for determining personal UV exposure; the effect of solar radiation management (stratospheric aerosol injections) on UV radiation relevant for plants; and possible revisions to the vitamin D action spectrum, which describes the wavelength dependence of the synthesis of previtamin D3 in human skin upon exposure to UV radiation. Graphical abstract

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Aerosol optical depth determination in the UV using a four-channel precision filter radiometer

Cited by 22 publications

References 61 publications

Aerosol optical depth in the European Brewer Network

Aerosol optical depth in the European Brewer Network

A climatology of aerosol optical depths in the ultraviolet wavelengths for Hobart, Australia, as determined by a Brewer MKIII spectrophotometer

Stratospheric ozone, UV radiation, and climate interactions

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