scholarly journals Comparison of UV Index and Total Ozone Column of Aura/OMI and Ground Measurement from Nepal Himalayas

1970 ◽  
Vol 8 (3) ◽  
pp. 114-129 ◽  
Author(s):  
Rishi R Sharma ◽  
Berit Kjeldstad ◽  
Binod K Bhattarai
Keyword(s):  
Total Ozone ◽  
Relative Difference ◽  
Transmission Factor ◽  
Horizontal Distance ◽  
Uv Index ◽  
Free Condition ◽  
Total Ozone Column ◽  
Cloudy Condition ◽  
Ground Measurement ◽  
Ozone Column

Ground UV index and total ozone measured from four stations of Nepal Himalaya using NILU UV Multiband Filter Radiometer (MBFR) were compared with that of the Aura/OMI satellite products using the data from October 2008 to December 2010. The main goal of the validation was to find how the satellite products deviate with that of ground measurement in the mountainous sites where the stations have unique set of geographical and environmental conditions. The altitudes of the stations vary from 72 m to 2850 m in a short span of horizontal distance. The comparison was done for clear-sky and cloudy-sky condition using Cloud Transmission Factor (CLT) as a proxy. It was found that UV indices estimated by the satellite have higher values compared to ground instrument. The relative difference (bias) of the four stations are varied from 34.5 ± 24.0% to 47.9 ± 17.4% for cloud free condition and from 106.4 ± 81.44 % to 286.4 ± 254.8% for cloudy condition. The correlation coefficients are more than 0.8 for cloud free condition. The total ozone column comparison showed the mean relative difference (bias) range from -2.17 ± 3.52% to 2.97 ± 3.92% under cloud free condition and -4.42 ± 5.64% to 1.36 ± 6.14% under cloudy condition. The possible factors for this discrepancy are discussed and some important factors are highlighted. DOI: http://dx.doi.org/10.3126/jie.v8i3.5938 JIE 2011; 8(3): 114-129

scholarly journals UV Index and Total Ozone Column Climatology of Nepal Himalaya Using TOMS and OMI Data

2016 ◽  
Vol 9 (1) ◽  
pp. 45-59
Author(s):  
R.R. Sharma ◽  
B. Kjeldstad ◽  
P.J. Espy
Keyword(s):  
High Altitude ◽  
Total Ozone ◽  
Extreme Values ◽  
Nepal Himalaya ◽  
Uv Index ◽  
Total Ozone Column ◽  
Clear Sky ◽  
Ground Measurement ◽  
Filter Radiometer ◽  
Ozone Column

Ultraviolet index (UVI) and Total Ozone Column (TOC) climatology of six stations of Nepal Himalaya using ground measurement, and OMI / TOMS satellite data is presented. The positive bias found in the OMI UV index from previous study is corrected empirically using a ratio factor using the clear sky coincident data of OMI and ground measurement from NILU UV multi-band filter radiometer (MBFR). UV index >3 in the winter months (e.g. December) and more than 9 during the summer months (May-August) are common in most of the stations. High altitude stations even have more extreme values (>11) during the summer months. Under some meteorological conditions, UV index often found more than 16 at the high altitude station (latitude 28o, altitude 2850m) during a clear sky day in the monsoon season. Diurnal and altitudinal variability is also highlighted. Monthly average TOC climatology from November 1978 to March 2012 using TOMS (Nimbus 7, Meteor3 and Earth Probe) and OMI is also presented. The ozone column data follows the annual cycle, minimum in November/December and maximum in April/May. In addition, slight negative trend of TOC is found in the data from 1978 to 2012.Journal of Hydrology and Meteorology, Vol. 9(1) 2015, p.45-59

scholarly journals ESTUDIO DE LA INFLUENCIA DE LAS NUBES SOBRE LA RADIACIÓN UV EN LA CIUDAD DE RÍO GALLEGOS, ARGENTINA. STUDY OF THE CLOUD INFLUENCE ON THE UV RADIATION IN RIO GALLEGOS, ARGENTINA

Anales AFA ◽  
2010 ◽  
pp. 266-271
Author(s):  
P. F. Orte ◽  
E. Wolfram ◽  
J. Salvador ◽  
R. D’Elia ◽  
C. Marinelli ◽  
...  
Keyword(s):  
Uv Radiation ◽  
Optical Thickness ◽  
Total Ozone ◽  
Ozone Layer ◽  
Ozone Hole ◽  
Ultraviolet Rays ◽  
Uv Index ◽  
Total Ozone Column ◽  
Cloud Optical Thickness ◽  
Ozone Column

The ozone layer is regarded as an invisible filter that protects all life from the dangerous overexposure to ultraviolet rays. The thinning of the ozone layer over the South Pole stratosphere of our planet is a seasonal phenomenon that takes place every year during the spring since the 80s and is known as the “ozone hole”. It is developed on the Antarctic, reaching an area of 30 million square kilometers approximately. In the spring begins to deform reached lower latitudes, presenting specific cases of low total ozone column over Rio Gallegos (51 ° 36 'S, 69 º 19' W) due to the passage of the hole and its border over this city, which can derive in UV indices greater increasing the UV radiation impact on surface. This study evaluates the statistical dependence of the UV index with total ozone column and cloud optical thickness in the Patagonian city of Rio Gallegos for spring and summer. Another aim is to quantify the attenuation of UV radiation produced for the clouds to cases that the ozone hole is passing over the city. The cloud optical thickness and UV index data analyzed were obtained at Station CEILAP RG (CITEFA-CONICET) with a narrowband multichannel radiometer GUV-541 (Biospherical Inc.), and the total ozone column data were extracted from the Satellite OMI / AURA database of NASA. All these belong to the spring and summer seasons of the October 2005-December 2008 period. It is noted that 25% of ozone hole cases in springtime, which would result in a high UVI on Rio Gallegos, are strongly attenuated by the clouds.

scholarly journals The unusual persistence of an ozone hole over a southern mid-latitude station during the Antarctic spring 2009: a multi-instrument study

2012 ◽  
Vol 30 (10) ◽  
pp. 1435-1449 ◽  
Author(s):  
E. A. Wolfram ◽  
J. Salvador ◽  
F. Orte ◽  
R. D'Elia ◽  
S. Godin-Beekmann ◽  
...  
Keyword(s):  
Total Ozone ◽  
Extreme Values ◽  
Polar Vortex ◽  
Relative Difference ◽  
Atmospheric Composition ◽  
Absolute Difference ◽  
Daily Maximum ◽  
Uv Index ◽  
Average Decrease ◽  
Ozone Column

Abstract. Record-low ozone column densities (with a minimum of 212 DU) persisted over three weeks at the Río Gallegos NDACC (Network for the Detection of Atmospheric Composition Change) station (51.5° S, 69.3° W) in November 2009. Total ozone remained two standard deviations below the climatological mean for five consecutive days during this period. The statistical analysis of 30 years of satellite data from the Multi Sensor Reanalysis (MSR) database for Río Gallegos revealed that such a long-lasting low-ozone episode is a rare occurrence. The event is examined using height-resolved ozone lidar measurements at Río Gallegos, and observations from satellite and ground-based instruments. The computed relative difference between the measured total ozone and the climatological monthly mean shows reductions varying between 10 and 30% with an average decrease of 25%. The mean absolute difference of total ozone column with respect to climatological monthly mean ozone column is around 75 DU. Extreme values of the UV index (UVI) were measured at the ground for this period, with the daily maximum UVI of around 13 on 15 and 28 November. The high-resolution MIMOSA-CHIM (Modélisation Isentrope du transport Méso-échelle de l'Ozone Stratosphérique par Advection) model was used to interpret the ozone depletion event. An ozone decrease of about 2 ppmv was observed in mid-November at the 550 K isentropic level (~22 km). The position of Río Gallegos relative to the polar vortex was classified using equivalent latitude maps. During the second week of November, the vortex was over the station at all isentropic levels, but after 20 November and until the end of the month, only the 10 lower levels in the stratosphere were affected by vortex overpasses with ozone poor air masses. A rapid recovery of the ozone column density was observed later, due to an ozone rich filament moving over Río Gallegos between 18 and 24 km in the first two weeks of December 2009.

scholarly journals Evaluation of Total Ozone Column from Multiple Satellite Measurements in the Antarctic Using the Brewer Spectrophotometer

2021 ◽  
Vol 13 (8) ◽  
pp. 1594
Author(s):  
Songkang Kim ◽  
Sang-Jong Park ◽  
Hana Lee ◽  
Dha Hyun Ahn ◽  
Yeonjin Jung ◽  
...  
Keyword(s):  
Satellite Data ◽  
Total Ozone ◽  
Spatiotemporal Pattern ◽  
Satellite Measurements ◽  
Austral Spring ◽  
Total Ozone Column ◽  
Brewer Spectrophotometer ◽  
The Antarctic ◽  
Ozone Column

The ground-based ozone observation instrument, Brewer spectrophotometer (Brewer), was used to evaluate the quality of the total ozone column (TOC) produced by multiple polar-orbit satellite measurements at three stations in Antarctica (King Sejong, Jang Bogo, and Zhongshan stations). While all satellite TOCs showed high correlations with Brewer TOCs (R = ~0.8 to 0.9), there are some TOC differences among satellite data in austral spring, which is mainly attributed to the bias of Atmospheric Infrared Sounder (AIRS) TOC. The quality of satellite TOCs is consistent between Level 2 and 3 data, implying that “which satellite TOC is used” can induce larger uncertainty than “which spatial resolution is used” for the investigation of the Antarctic TOC pattern. Additionally, the quality of satellite TOC is regionally different (e.g., OMI TOC is a little higher at the King Sejong station, but lower at the Zhongshan station than the Brewer TOC). Thus, it seems necessary to consider the difference of multiple satellite data for better assessing the spatiotemporal pattern of Antarctic TOC.

Validation of gome total ozone column with the assimilation model KNMI

1998 ◽  
Vol 22 (11) ◽  
pp. 1501-1504
Author(s):  
A.J.M Piters ◽  
P.F Levelt ◽  
M.A.F Allaart ◽  
H.M Kelder
Keyword(s):  
Total Ozone ◽  
Total Ozone Column ◽  
Ozone Column ◽  
Assimilation Model

scholarly journals Seasonal impact of biogenic VSL bromine on the evolution of mid-latitude lowermost stratospheric ozone during the 21<sup>st</sup> century

2020 ◽  
Author(s):  
Javer A. Barrera ◽  
Rafael P. Fernandez ◽  
Fernando Iglesias-Suarez ◽  
Carlos A. Cuevas ◽  
Jean-Francois Lamarque ◽  
...  
Keyword(s):  
21St Century ◽  
Total Ozone ◽  
Stratospheric Ozone ◽  
Polar Regions ◽  
Total Ozone Column ◽  
Seasonal Impact ◽  
The Tropics ◽  
The Impact ◽  
Ozone Column ◽  
Modelling Study

Abstract. Biogenic very short-lived bromine (VSLBr) represents, nowadays, ~ 25 % of the total stratospheric bromine loading. Owing to their much shorter lifetime compared to anthropogenic long-lived bromine (LLBr, e.g., halons) and chlorine (LLCl, e.g., chlorofluorocarbons) substances, the impact of VSLBr on ozone peaks at the extratropical lowermost stratosphere, a key climatic and radiative atmospheric region. Here we present a modelling study of the evolution of stratospheric ozone and its chemical losses in extra-polar regions during the 21st century, under two different scenarios: considering and neglecting the additional stratospheric injection of 5 ppt biogenic VSLBr naturally released from the ocean. Our analysis shows that the inclusion of VSLBr result in a realistic stratospheric bromine loading and improves the quantitative 1980–2015 model-satellite agreement of total ozone column (TOC) in the mid-latitudes. We show that the overall ozone response to VSLBr within the mid-latitudes follows the stratospheric abundances evolution of long-lived inorganic chlorine and bromine throughout the 21st century. Additional ozone losses due to VSLBr are maximised during the present-day period (1990–2010), with TOC differences of −8 DU (−3 %) and −5.5 DU (−2 %) for the southern (SH-ML) and northern (NH-ML) mid-latitudes, respectively. Moreover, the projected TOC differences at the end of the 21st century are at least half of the values found for the present-day period. In the tropics, a small (

scholarly journals Brewer spectrometer total ozone column measurements in Sodankylä

2016 ◽  
Vol 5 (1) ◽  
pp. 229-239 ◽  
Author(s):  
Tomi Karppinen ◽  
Kaisa Lakkala ◽  
Juha M. Karhu ◽  
Pauli Heikkinen ◽  
Rigel Kivi ◽  
...  
Keyword(s):  
Time Series ◽  
Total Ozone ◽  
Montreal Protocol ◽  
High Quality ◽  
Automatic Data ◽  
Mean Values ◽  
Total Ozone Column ◽  
Measurement Practices ◽  
Ozone Column

Abstract. Brewer total ozone column measurements started in Sodankylä in May 1988, 9 months after the signing of The Montreal Protocol. The Brewer instrument has been well maintained and frequently calibrated since then to produce a high-quality ozone time series now spanning more than 25 years. The data have now been uniformly reprocessed between 1988 and 2014. The quality of the data has been assured by automatic data rejection rules as well as by manual checking. Daily mean values calculated from the highest-quality direct sun measurements are available 77 % of time with up to 75 measurements per day on clear days. Zenith sky measurements fill another 14 % of the time series and winter months are sparsely covered by moon measurements. The time series provides information to survey the evolution of Arctic ozone layer and can be used as a reference point for assessing other total ozone column measurement practices.

Variations in total ozone column and biologically effective solar UV exposure doses in Bologna, Italy during the period 2005–2010

2013 ◽  
Vol 58 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Boyan Petkov ◽  
Vito Vitale ◽  
Claudio Tomasi ◽  
Mauro Mazzola ◽  
Christian Lanconelli ◽  
...  
Keyword(s):  
Total Ozone ◽  
Uv Exposure ◽  
Total Ozone Column ◽  
Solar Uv ◽  
Ozone Column
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