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Atmospheric Science Events in 2012

2011-12-11T05:51:00.000-08:00

During the next year 2012, there will take place several interesting conferences related to the Atmospheric Sciences:

- International Radiation Symposium, 6-10 August, Berlin, Germany

- Quadrennial Ozone Symposium, 27-31 August, Toronto, Canada

- European Aerosol Conference, 2-7 September, Granada, Spain

- Atmospheric Science Conference, 18-22 June, Bruges, Belgium

- EUMETSAT Meteorological Satellite Conference, 3-7 September, Sopot, Poland

- EGU General Assembly, 22-27 April, Vienna, Austria

- SPIE Remote Sensing, 24-27 September, Edinburgh, United Kingdom.

- IEEE Geoscience and Remote Sensing Symposium, 22-27 July, Munich, Germany

- International Conference on Clouds and Precipitation, July 30 - August 03, Leipzyg, Germany

- European Meeting on Atmospheric Studies by Optical Methods, 20-24 August, Sopot, Poland

- International Conference on Meteorology, Climatology and Atmospheric Physics, May 30 - 1 June, Athens, Grecee

Long‐term solar erythemal UV irradiance data reconstruction

2011-11-30T04:27:00.000-08:00

A very interesting paper has been just published in JGR (doi:10.1029/2011JD015836). My colleagues from the University of Valladolid (Julia Bilbao, Roberto Román, Argimiro de Miguel and David Mateos) have proposed a semiempirical method to obtain a long-term reconstructed series of ultraviolet erythemal irradiance (UVER) in Spain. For that, total shortwave radiation and total ozone columns measurements from satellite have been used.

The reconstructed hourly UVER irradiance values are in good agreement with the measurements in the seven locations, showing low RMSE values in summer (from 5% to 9%). A reconstructed 10 min UVER data set from 1991 to 2010 has been derived from the proposed method. Statistically significant UVER trends appear in summer and autumn when UVER levels increased 3.5% and 4.1% per decade, respectively.

Atmospheric Composition Portal

2011-09-05T02:46:00.000-07:00

The Atmospheric Composition Portal (ACP) aims to provide a community-oriented framework that applies best practices in information science and technology to atmospheric composition science. This portal is being developed by the Atmospheric Composition Constellation (ACC) and the Workgroup for Information Systems and Services (WGISS) within the Committee on Earth Observation Satellites (CEOS).

Effects of an asteroid strike into ocean on the ozone layer

2011-07-09T03:58:00.000-07:00

A very interesting paper “Ozone perturbation from medium-size asteroid impacts in the ocean” by Pierazzo et al. has been published in Earth and Planetary Science Letters. These authors have shown by simulations that if an asteroid 500 m to 1 km in diameter were to hit the Pacific Ocean it would eject enough water vapor and sea salt into the atmosphere to affect the ozone layer.

The simulations showed that mid-latitude oceanic impacts of 1 km asteroids could produce a significant, global perturbation of upper atmospheric chemistry, including multi-year global ozone depletion comparable to ozone hole records registered in the mid-1990s. In addition, this ozone depletion would produce ultraviolet index (UVI) levels higher than 20 at the Earth’s surface during about two years in both the northern and southern hemispheres.

ACTRIS Project

2011-06-04T01:26:00.000-07:00

ACTRIS (Aerosols, Clouds, and Trace gases Research InfraStructure Network) is a European Project aiming at integrating European ground-based stations equipped with advanced atmospheric probing instrumentation for aerosols, clouds, and short-lived gas-phase species. This European ground-based network will contribute to:

- providing long-term observational data relevant to climate and air quality research produced with standardized or comparable procedures;

- supporting transnational access to large infrastructures strengthening collaboration in and outside the EU and access to high quality information and services to the user communities;

- developing new integration tools to fully exploit the use of atmospheric techniques at ground-based stations, in particular for the calibration/validation/integration of satellite sensors and for the improvement of global and regional-scale climate and air quality models.

New version of TOGOMI/TOSOMI retrieval algorithms

2011-05-15T02:27:00.000-07:00

The two European satellite-borne atmospheric sensors Global Ozone Monitoring Experiment (GOME) and the SCanning Imaging Absorption spectrometer for Atmospheric CHartographY (SCIAMACHY) are currently operational and offer the potential for an assessment of the global total ozone distribution covering an expected time span of over 18 years.

The Royal Netherlands Meteorological Institute (KNMI) has developed two retrieval algorithms to derive the total ozone data from these two European satellite instruments. These two retrieval algorithms are the Total Ozone retrieval scheme for the GOME instrument based on the OMI DOAS algorithm (TOGOMI), and the corresponding application to the SCIAMACHY instrument (TOSOMI).

A new version (2.0) of these two retrieval algorithms has been prepared by KNMI staff, and the new total ozone data are distributed via internet from the Tropospheric Emission Monitoring Internet Service (TEMIS)

Ozone depletion and climate change: impacts on UV radiation

2011-04-02T08:28:00.000-07:00

A really interesting paper has been recently published by McKenzie et al. in Photochem. Photobiol. Sci.. This article presents a well documented review of the relationship between ozone depletion and climate change and its influence on the UV radiation at Earth’s surface. The paper indicates that because of the success of the Montreal Protocol, increases in UV-B radiation during the last two decades have been small outside regions affected by the Antarctic ozone hole. In addition, other atmospheric factors (mainly clouds and aerosols) also play an outstanding role on the variability of UV radiation at surface. Thus, the influence of the ozone depletion (and its recovery) on the UV radiation has been difficult to detect at mid-latitudes. The authors state that “without the Montreal Protocol, peak values of sunburning UV radiation could have been tripled by 2065 at mid-northern latitudes.”.

Regarding the interactions between ozone and climate change, the paper analyses both the effects of the implementation of the Montreal Protocol on climate change, and the influence of the increasing greenhouse gases on ozone recovery.

Sixth Regional Brewer Calibration Center for Europe intercomparison

2011-03-01T08:07:00.000-08:00

The 6th Regional Brewer Calibration Center for Europe (RBCC-E) intercomparison will be held at El Arenosillo Atmospheric Sounding Station of the "Instituto de Técnica Aeroespacial" (INTA) during the period July 5 to 15 2011. This will be a join execercise of the Dobson and Brewer calibration centers for Europe. The QASUME unit of the Physikalisch-Meteorologisches Observatorium Davos / World Radiation Center (PMOD /WRC) will participate and provide a global UV reference spectrum for the ultraviolet measurements.
The campaign is scheduled in three main phases:
* Initial calibration to assess the current calibration of the instruments.
* Servicing, adjustments and maintenance works characterization test of the instruments.
* Final calibration. In this phase the ‘UV’ calibrations against the QASUME
Specific measurements for Brewer/Dobson comparison

Detailed information is available at the RBCC-E web page.

Ozone_cci project

2011-01-17T04:40:00.000-08:00

The Ozone_cci project is part of the ESA Climate Change Initiative (CCI) Programme. Ozone_cci will develop, produce and validate long-term series of high quality global observations of atmospheric ozone derived from multiple satellite instruments that are essential to assess the fate of atmospheric ozone.
The task of the ESA Ozone-cci project is to improve on the scientific and operational exploitation of current European and Third Party Mission ozone monitoring sensors, by creating merged multi-sensors Essential Climate Variable (ECV) ozone time series that match the requirements formulated by GCOS, and allow reducing current uncertainties on the determination of ozone trends.
The Ozone_cci project team consists of 13 European partner institutions which are experts in the area of satellite retrieval algorithms, geophysical validation, system engineering and chemistry-climate modelling.

Scientific Assessment of Ozone Depletion 2010

2010-12-26T01:28:00.000-08:00

The WMO/UNEP “Scientific Assessment of Ozone Depletion: 2010” will be ready in early 2011, but the executive summary of this report is already available. It provides new information about the relationship between the ozone layer and climate change, and highlights the successful implementation of the Montreal Protocol and its amendments.
The summary states that over the past decade, global ozone is no longer decreasing but is not yet increasing. Using numerical models of the Earth’s atmosphere, the report predicts that the stratospheric ozone layer will fully recover within the next 50 years.
Regarding the influence of ozone changes on ultraviolet radiation, the executive summary says that large UV levels in Antarctica continue to be seen when the springtime ozone hole is large. For instance, the Antarctic spring erythemal irradiance is approximately twice that measured in the Arctic for the same season. In addition, it is reaffirmed that at mid-latitudes, surface UV radiation has been about constant over the last decade, consistent with total ozone column observations over this period.

The empirically corrected TOMS data

2010-11-30T11:39:00.000-08:00

In July 1996, the Total Ozone Mapping Spectrometer (TOMS) instrument was launched on the Earth Probe (EP) satellite. The total ozone column (TOC) observations derived from this satellite instrument began to display significant deviations from the ground truth by the middle of the year 2000. Haffner et al. (2004) indicated that the detected error in the instrument performance appears to depend on latitude, season, lifetime, and wavelength Thus, NASA GSFC warned users that EP-TOMS TOC data after the year 2000 are not recommended for the calculation of long-term ozone trends. To correct the influence of this instrument degradation, an empirical calibration technique was applied to the TOC data according to the personal comunication of McPeters et al. (2007). This empirically corrected TOMS data (EP-TOMS V8-corrected) has been made available since September 2007. The recent paper of Antón et al. (2010) presented the global comparisons between the TOC satellite observations derived from the V8-original and V8-corrected EP-TOMS data using reliable ground-based measurements as reference.This work showed that EP-TOMS V8-corrected total ozone data present a remarkable improvement concerning the significant negative bias of around ∼3% detected in the EP-TOMS V8-originnal observations after the year 2000.

Solar minimum 2008-2009

2010-10-13T11:21:00.000-07:00

The descending phase of solar cycle 23 was long and gradual, and during 2008–2009, solar activity became extremely low. In late 2009, solar activity finally started to increase, but the period between mid-2007 and mid-2009 was one of the longest of recent solar minima. Recently, several interesting papers have been published about this subject. The work of Fröhlich (2010) has shown that the value of total solar irradiance during the solar minimum of 2008-2009 was more than 0.2 Wm−2 smaller than during the last minimum in 1996. Solomon et al. (2010) have indicated that that solar extreme ultraviolet irradiance levels during the solar minimum of 2008-2009 were also lower than they were during the previous solar minimum. Haigh et al. (2010) have shown that these spectral changes appear to have led to a significant decline from 2004 to 2007 in stratospheric ozone below an altitude of 45 km. Garcia (2010) states that these implications for Earth’s atmosphere must be viewed as provisional.

The First WMO Antarctic Ozone Bulletin of 2010

2010-09-07T09:47:00.000-07:00

The WMO Antarctic Ozone Bulletin contains information on the state of the ozone layer in the Antarctic at roughly two week intervals from August to November. The bulletins are based on ground-based ozone data provided by WMO Members and satellites to observe ozone globally. The first bulletin in 2010 (7.2 MB) indicates "that the area where total ozone is less than 220 DU (“ozone hole area”) is low compared to recent years", adding that its evolution will depend on the meteorological conditions between now and early October, when depletion usually ends. Thus, "it is still too early to give a definitive statement about the development of this year's ozone hole and the degree of ozone loss that will occur", the bulletin stated.

New UV forecasting website

2010-08-12T02:18:00.000-07:00

The new UV forecasting website - http://uvawareness.com/ - is a very useful tool. It provides a four day hourly UV forecast from 6 a.m. to 6 p.m. for just about any location world wide.
This UV forecast data is harnessed from NOAA UV Index forecasting which uses the TUV radiative transfer code for deriving the erythemally weighted downwelling UV fluxes. This NOAA UV Index is computed using forecasted ozone data, and cloud amounts. In addition, climatological aerosol loading, variable snow and constant bare earth albedo, and elevation are used in the model.

Influence of ozone mini-holes on UV radiation

2010-07-22T02:38:00.000-07:00

The International Journal of Climatology has recently published two papers about the ozone mini-holes effects over the UV radiation. Sola and Lorente study the impact of two mini-holes on erythemal UV irradiance over Barcelona (Spain). They find that this irradiance at noon was 36% higher on 10 January 2004 than the day before. This date corresponds with the minimum total ozone value recorded over the Iberian Peninsula. On the other hand, Martinez-Lozano et al. analyzed the low ozone level episodes over Valencia (Spain) during 2000-2007. The increase of UV radiation related to the decrease in total ozone is quantified at 1.29 times this decrease

Final Report COST 726

2010-06-07T06:52:00.000-07:00

The final report of the the COST Action 726 “Long term changes and climatology of UV radiation over Europe” is available in its web page . The main objective of this action was to advance the understanding of UV radiation distribution under various meteorological conditions in order to determine a UV radiation climatology and assess UV changes over Europe.

The report has been written by leader authors, but it is a result of the collective efforts of the members of the four Working Groups, coming from 23 countries. CONGRATULATIONS!!!!!

The 25 anniversary of the discovery of the Antarctic ozone hole

2010-05-11T07:42:00.000-07:00

To mark the 25 anniversary of the discovery of the Antarctic ozone hole, the prestigious journal Nature presents the original research paper reporting the high ozone decline over Antarctica in spring. In addition, a new Opinion piece from one of the paper's authors, plus a collection of related articles that have advanced our understanding of the stratosphere and the ozone layer.

Access selected content from the web focus free online:
the 25 anniversary of the discovery of the Antarctic ozone hole

UV radiation, Ozone and Aerosols over the Iberian Peninsula

2010-04-19T07:21:00.000-07:00

The JGR has recently published three papers about these topics. Bilbao and de Miguel (2010) studied an empirical relationship between the solar ultraviolet-B (UV-B) in the range (280–315 nm) and the total global solar irradiation (G) in Valladolid (Spain). The results showed that G is an appropriate variable to obtain UV-B daily values in places where UV radiation is not measured or to extend the existing data set back in time. Mladenove et al. (2010) analyzed the relationships between spectroscopic (fluorescence and absorbance) properties of the water-soluble organic compounds in aerosol deposition and ground-based remote sensing measurements of aerosols in the atmospheric column in Granada (Spain). They found important differences between Saharan- and marine-dominated organic aerosols. Antón et al (2010) compared the total ozone retrieved with the passive DOAS methodology from zenith-sky observations by the SPATRAM spectrometer located in Evora (Portugal) with highly accurate total ozone data retrieved from direct-sun recordings by a well-calibrated Brewer instrument in El Arenosillo (Spain). The results showed that the differences observed between both systems is not associated with the natural spatial variability of the total ozone.

e-Atlas of erythemally UV Climatology over Europe

2010-03-05T00:01:00.000-08:00

The COST ACTION 726 - Long term changes and climatology of Ultraviolet radiation over Europe - has just presented the "Electronic Atlas" of UV Climatology over Europe. This atlas enables you to extract reconstructed erythemally weighted daily dose values for a certain location and a certain period. Data are available from 1.1.1958 to 31.8.2002 for longitudes from 25°E to 35°W and latitudes from 30°N to 80°N. These data are mean values over an area of 1°x 1°. It is possible to extract daily values, monthly sums and to calculate a simple annual statistics.

The atlas is free for non-comercial use, and it can be downloaded in the following web:

http://www.cost726.org/

The World Avoided by protecting the ozone layer

2010-02-12T06:40:00.000-08:00

There are several very interesting papers in literature that analyse a future world where ozone depleting substances were never regulated by the Montreal Protocol. This protocol signed in 1989 was the first international agreement on regulation of chemical pollutants, and it is widely considered the most successful environmental treaty. Newman et al (ACP, 2009) show that 17% of the globally-averaged column ozone is destroyed by 2020, and 67% is destroyed by 2065 in comparison to 1980. Ozone levels in the tropical lower stratosphere remain constant until about 2053 and then collapse to near zero by 2058. Morgenstern et al. (GRL, 2008) indicate that the Montreal Protocol has not only averted further damage to the ozone layer but has helped prevent significant regional climate change. In this sense, Molina et al. (PNAS, 2009) state that the strengthening of the Montreal Protocol can phase down the production and consumption of hydrofluorocarbons (HFCs) with high global warming potential. According the authors, this and other strategies may reduce the risk of abrupt climate change in the next few decades.

Interesting events in 2010

2010-01-07T23:03:00.001-08:00

During the year 2010, there will take place several interesting events related to the Atmospheric Sciences:

- EGU (European Geosciences Union, General Assembly 2010), 2-7 May, Vienna, Austria.

- 37th Annual European Meeting on Atmospheric Studies by Optical Methods , 23-27 August, Valladolid, Spain.

- IAC (International Aerosol Conference) , 29 August- 3 September, Helsinki, Finland.

- SPIE Remote Sensing, 20-23 September, Toulouse, France.

- EUMETSAT Meteorological Satellite Conference, 20-24 September, Cordoba, Spain.

Atmospheric aerosol charecterization

2009-11-22T03:26:00.000-08:00

A very interesting paper has been recently published in ACP about the atmospheric aerosol characterization for North Africa, Northeastern Atlantic, Mediterranean and Middle East. This work is based on the analysis of quality-assured direct-sun observations of 39 stations of the AErosol RObotic NETwork (AERONET). Its main objectives are two: to discriminate different aerosol types and to quantify the contribution of mineral dust. Large mineral dust is found to be the most important constituent in Northern Africa and Middle East. Under specific meteorological conditions, its transport to Southern Europe is observed from spring to autumn and decreasing with latitude.

More information in:

http://www.atmos-chem-phys.org/9/8265/2009/acp-9-8265-2009.html

New OMI Ozone Profile data release

2009-10-29T01:29:00.000-07:00

OMI Ozone Profile data (OMO3PR) is given in terms of the layer-columns of ozone in Dobson Unit (DU) for an 18-layer atmosphere. The layers are nominally bounded by the pressure levels: surface pressure, 700, 500, 300, 200, 150, 100, 70, 50, 30, 20, 10, 7, 5, 3, 2, 1, 0.5, and 0.3 hPa.

Detailed information about this product can be found at:

OMO3PR README File

Full OMO3PR data, as well as subsets of these data over many ground stations and along Aura validation aircraft flights paths are available through the Aura Validation Data Center (AVDC) website

The Cal/Val Wiki Page

2009-10-14T01:19:00.000-07:00

The Calibration (Cal) and Validation (Val) Portal of the European Space Agency (ESA) has a very nice tool where the community can edit or insert new topic regarding the Calibration and Validation of Satellite Data. The name is The Cal/Val Wiki Page.

The link to this page is the following: http://calvalportal.ceos.org/cvp/web/guest/cal/val-wiki

GlobAEROSOL

2009-09-23T10:17:00.000-07:00

GlobAEROSOL is a project whose aim is to produce a global aerosol data set (1995-2007) from merging ATSR-2, AATSR, MERIS and SEVIRI satellite data.

The specific objetives of this project are:
1. Development of a satellite data processing system to generate a standard reference multi-year global aerosol product (GAP) over land and water.
2. Production of the GAP covering 1995–2007.
3. Validation of the GAP using independent ground-based measurements.
4. Intercomparison of the GAP with other satellite-based aerosol data sets.

Detailed information in: http://www.globaerosol.info/

Global long-term monitoring of the ozone

2009-09-04T08:58:00.000-07:00

My colleague Diego Loyola from German Aerospace Center (DLR) has been just published an interesting article in International Journal of Remote Sensing. This paper demonstrates the importance of a consistent multi-year dataset of total ozone which is composed from different satellite instruments (GOME (ERS-2), SCIAMACHY (ENVISAT), and GOME-2 (METOP-A)). In addition, the paper gives some examples of how to use satellite data products to evaluate model results with respective data derived from observations, and to disclose the abilities and deficiencies of atmospheric models.

View/Download this Publication (PDF, 3 MB)

Spanish Lidar Network (SPALINET)

2009-08-20T04:21:00.000-07:00

The Spanish Lidar Network (http://www.lidar.es/spalinet/en/) was created on 1 January, 2007. It aims to promote the use of lidar instruments and data among the Spanish scientific community. The mains goals of the network are:

• Extend and reinforce the actions of EARLINET (European Aerosol Research Lidar Network to Establish an Aerosol Climatology).
• The formation of a nucleus for the development of the Spanish and Portuguese lidar community.
• Promote the participation of new groups for improving the spatial coverage of aerosol vertical measurements on the Iberian Peninsula territory.

COST 726 Aerosol Climatology over Europe

2009-07-28T04:53:00.000-07:00

The COST 726 Aerosol Climtology over Europe (25°W to 35°E and 31°N to 80°N) consists of monthly mean values of AOT at 308 nm in one data file (ascii).

If altitude is higher than 1 km the following correction should be applied: AOT=AOT / (altitude[km])^1.65

Further:
Angstrom coefficient: 1
Single scattering albedo: 0.94
Asymmetry factor: 0.75

This climatology is free for non-comercial use.

A brief history of stratospheric ozone research

2009-07-04T08:10:00.000-07:00

Rolf Müller has published an interesting review of the stratospheric ozone research in Meteorologische Zeitschrift. This paper describes the discovery of ozone and the first tropospheric measurements, covering the discovery of the role of ozone as an absorber of solar radiation, and the first measurements of total column ozone. In addition, it presents the development of the understanding of the chemistry of stratospheric ozone, and the discovery of the ozone hole.

The full text can be downloaded in the following link:

http://www.ingentaconnect.com/content/schweiz/mz/2009/00000018/00000001/art00001;jsessionid=8g0gbb35r4edd.alexandra

The European Ozone Research Coordinating Unit

2009-06-19T10:34:00.000-07:00

The European Ozone Research Coordinating Unit (EORCU) coordinates the atmospheric research within Europe, establishing worldwide links within the global atmospheric science community by means of coordinating large scale field campaigns, organising conferences and workshops.

EORCU currently coordinates the Stratospheric-Climate Links with Emphasis on the Upper Troposphere and Lower Stratosphere (SCOUT-O3) Project.

Report of the “El Arenosillo”/INTA-COST Calibration Campaign of UVER Radiometers

2009-06-01T07:45:00.000-07:00

The El Arenosillo/INTA calibration and intercomparison campaign of UVER Broadband radiometers held in the observatory “El Arenosillo” (Spain) from 15 August to 21 September 2007. This event was part of the COST Action 726 Working Group 4 activities. The main procedures and results of this campaign have been published in the following report:

COST Action 726 - Report of the “El Arenosillo”/INTA-COST Calibration and Intercomparison Campaign of UVER Broadband Radiometers
ISBN: 978-84-692-2640-7

View/Download this Publication (pdf, 4 MB)

Interesting events in September 2009

2009-05-14T07:19:00.000-07:00

In the next month of September, two important events will take place in Spain:

- The FOURTH INTERCOMPARISON CAMPAIGN OF THE REGIONAL BREWER CALIBRATION CENTER-EUROPE (RBCC-E) in a joint intercomparison campaign with the Regional Dobson Calibration Center-Europe (RDCC-E) will be held at the El Arenosillo Atmospheric Sounding Station - INTA (Huelva) during the period September 7th-17th, 2009

- The ATMOSPHERIC SCIENCE CONFERENCE, organised by the European Space Agency in Barcelona, 7-11 September 2009.

Altitude effect in UV radiation

2009-05-07T01:55:00.000-07:00

The Research Group of Meteorology and Geophysics belonging to the University of Barcelona has just published an interesting paper in JGR. This article analyses the altitude effect (AE) for UV irradiance under cloudless conditions by taking spectral and broadband measurements in SE Spain at three nearby sites located at different heights (680 m, 2200 m, and 3398 m). The study was within The Evaluation of the Effects of Elevation and Aerosols on the Ultraviolet Radiation 2002 (VELETA-2002) field campaign. The AE for erythemally weighted irradiance ranged from 11 to 14% km−1between the lowest and highest stations when it was calculated from spectral measurements. Saharan dust caused an increase in AE, especially in the UVB region and in the erythemal irradiance.

NEUBrew

2009-03-29T04:42:00.000-07:00

The NOAA/EPA Brewer Spectrophotometer UV Monitoring Network (NEUBrew) is comprised of six Brewer Mark IV spectrophotometers located in the western, central and eastern United States. In addition to the Brewer instruments each site is equipped with considerable ancillary instrumentation that allows for expanded research opportunities. The NEUBrew website provides access to calibrated network data, data products, and on-line graphics displays for data and diagnostics.

The NEUBrew website is:
http://esrl.noaa.gov/gmd/grad/neubrew/

Total Ozone Climatology 1950-2004

2009-03-16T10:01:00.000-07:00

The COST 726 Total Ozone Climatology (COC) consists of two data files and a easy to use program to extract a time series for a certain location. The program only needs latitude and longitude (decimal point) divided by a comma as input (e.g. 52.21,15.33). Time series, daily means for the period 01.01.1950 - 31.12.2004 is stored in a simple ASCII-file.

Download:
http://tau.igf.edu.pl/~jkrzys/

Reference:
Krzyscin, J.W., Statistical Reconstruction of Daily Total Ozone over Europe 1950 to 2004, Journal of Geophysical Research, Vol.113, D07112, doi: 10.1029/2007JD008881, 2008

Forums of the O3M SAF project

2009-03-03T01:11:00.000-08:00

The first products of the Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M SAF) (http://o3msaf.fmi.fi) have been declared operational. In this framework, a combined User Forum and Algorithm Forum workshop will be carried out in Greece between 2-4 June, 2009. The aim of the User Forum is to gather feedback from the user community on specific services and products disseminated by the O3M SAF. On the other hand, the aim of the Algorithm forum is to bring together the product developers of the team with other algorithm experts sharing their technical expertise and experience.

The most up-to-date information can be found from the web page:
http://o3msaf.fmi.fi/forum/index.html

Direct SW aerosol radiative forcing over Portugal

2009-02-17T00:43:00.000-08:00

The aerosol research team belong to the Geophysics Centre of Évora (Portugal) has published an interesting article in ACP. This paper analyses the evaluation of the aerosol radiative forcing at the top of the atmosphere as well as at the surface over two ground-based stations located at the south of Portugal. The instantaneous direct SW aerosol radiative forcing values obtained at the top of the atmosphere are, in the majority of the cases, negative, indicating a tendency for cooling the Earth at the top of the atmosphere. The average surface direct SW aerosol radiative forcing efficiency is also negative with the more negative values corresponding to forest fire aerosols.

Met-jobs

2009-02-03T08:55:00.000-08:00

If you would like to receive regular mailings of job adverts in Atmospheric Science, please visit the Met-jobs mailing list

To see the collection of prior postings to the list, visit the Met-jobs Archives.

12th Biennial WMO-GAW Brewer Users Group Meeting

2009-01-20T07:26:00.000-08:00

This workshop will focus on the science and technical issues of the Brewer instrument and its role in the global ozone, aerosol and UV monitoring networks. In addition, there will also be a special data analysis session aimed at helping Brewer users perform the analysis and quality control functions needed to prepare Brewer data records for use in the 2010 WMO Ozone Assessment.

The meeting will be hosted by the Aosta Valley Regional Environmental Protection Agency (ARPA), Aosta (Italy), 20-26 September 2009.

More information in the meeting web site.

The strongest desert dust intrusion over the Iberian Peninsula

2008-12-17T00:35:00.000-08:00

Cachorro et al. have published an interesting article in JGR. They analyze the strongest desert dust intrusion that occurred over the Iberian Peninsula (IP) during the last decade registered with Sun photometry. This extreme episode took place from 22 July to 3 August 2004. The most relevant features of this exceptional event, originated over the Saharan desert, were its great intensity and duration. Aerosol optical depth (AOD) reached a maximum of 2.7 at El Arenosillo during 22 July and 1.3 at Palencia on 23 July, with the Ansgtrom exponent values near zero during the AOD peaks.

Ozone Monitoring Instrument

2008-11-17T02:49:00.000-08:00

The OMI satellite instrument is a contribution of the Netherlands's Agency for Aerospace Programs (NIVR) in collaboration with the Finnish Meteorological Institute (FMI), and it is onboard NASA EOS/Aura platform launched in July 2004. This remote sensing UV spectrometer continues currently with the measurements recorded by the NASA Total Ozone Mapping Spectrometer (TOMS) instrument which was operative on board of two satellites: Nimbus-7 (1978-1993) and Earth Probe (EP) (1996-2005).

The total ozone column over many locations (in Spain: Badajoz, El Arenosillo, Madrid and Valencia ) can be obtained in the following ftp site:

ftp://toms.gsfc.nasa.gov/pub/omi/data/overpass

Active fire monitoring over continental Portugal

2008-10-13T00:23:00.000-07:00

The Active Fire Monitoring (FIR) is a product that displays information on the presence of fire within a pixel and it is obtained directly from the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT). The information for continental Portugal is made available in this page in near real time (15 to 20 minutes delay) with a spatial resolution of 3×3km².

The 2008 ozone hole

2008-10-08T23:51:00.000-07:00

The 2008 ozone hole is larger both in size and ozone loss that 2007 but is not as large as 2006.

More information in: ESA News

Ozone trends at northern mid- and high latitudes

2008-07-17T05:44:00.000-07:00

The paper "Ozone trends at northern mid- and high latitudes – a European perspective" by Harris et al., has been recently published in Annales Geophysicae. This interesting paper shows the main conclusions of the EU CANDIDOZ project which investigated the chemical and dynamical influences on decadal ozone trends focusing on the Northern Hemisphere. The results shows an almost monotonic negative trend from the late 1970s to the mid 1990s followed by an increase in the NH mid latitudes and in the Arctic. The article analyzes the chemical and dynamical causes of this ozone increase.

Training School over UV Radiation

2008-06-25T06:50:00.000-07:00

This “Training School” is organized by the COST 726: Long term changes and climatology of biologically effective UV Radiation over Europe. The main objetive is the understanding of biologically effective solar UV radiation in an interdisciplinary context, using the knowledge base and results from COST Action 726. A further aim is to educate a pool of national experts with the knowledge and international contacts to promote and disseminate their understanding of recent and past values of biologically effective UV radiation across all fields of science.

More information in the web of COST Action 726

Ozone mini-holes

2008-02-20T02:01:00.000-08:00

Extreme low ozone episodes called ozone mini-holes are characterized by a quick and small-scale decrease in total ozone amount followed by an equally rapid recovery after a few days. These anomalous events have been observed in both hemispheres in winter or early spring. In mid-latitudes, these episodes can be explained by different dynamic processes such as the displacement of the polar vortex, the influence of planetary waves, the advection from the tropics of air patches with low total ozone content and vertical uplift of isentropic air-mass in the lower and middle stratosphere.

The following article analyses the main characteristic of these anomalous events:

Bojkov, R. D., and D. S. Balis (2001), Characteristics of episodes with extremely low ozone values in the northern middle latitudes 1957 –2000, Ann. Geophys., 19, 797– 807.

International Radiation Symposium 2008

2008-01-27T12:51:00.000-08:00

The International Radiation Symposium (IRS2008) on Current Problems in Atmospheric Radiation will be held during August 3-8, 2008 at Foz do Iguaçu, Brazil. The Symposium is organized every four years by the International Radiation Commission (IRC). This will be the first edition in South America and is an opportunity to share ideas and experiences on the current problems in atmospheric radiation from theory and modeling to measurements and applications on weather and climate.

More information in the following link:

IRS2008

Ozone vs. Climate change

2008-01-17T13:18:00.000-08:00

Ozone and climate change are linked in two important ways:

The greenhouse gases produces near-surface global warming. This fact is expected to cool the stratosphere, and in turn, it is expected to produce a relative increase in stratospheric ozone depletion.
Conversely, ozone is a radiative forcing of the climate system. There are two opposing effects. On the one hand, ozone increases in the troposphere from pollution associated with human activities leads to a warming of Earth’s surface. In contrast, stratospheric ozone depletion represents a small negative forcing, which leads to cooling of Earth’s surface.

There are several interesting links which detail this subject:

European Fleet for Airborne Research (EUFAR)

2008-01-11T13:17:00.000-08:00

EUFAR (http://www.eufar.net/) is an European project which aims at coordinating the operations of the European fleet of instrumented aircraft in the field of environmental research in the atmospheric, marine, terrestrial and Earth sciences. EUFAR is divided in several expert working groups such as aerosols, radiation and remote sensing.

EUFAR is organizing its 2nd Summer School on Airborne Cloud and AerosolScience (ACAS) open to PhD students and Post Docs. This school will take place in Utrecht, The Netherlands from April 14th to April 25th 2008. The aim of the school is to train students in airborne research focused on aerosols and clouds.

ORACLE-O3

2008-01-06T12:45:00.000-08:00

The project "Ozone layer and UV radiation in a changing climate evaluated during the IPY (ORACLE-O3)" deals with experimental and modelling research on the ozone layer, UV radiation and the effects of personal UV exposure during the International Polar Year 2007-2008 (IPY). This project is divided into 7 main activities:

Ozone loss (detection and impact on UV radiation)
PSC and cirrus
Atmospheric chemistry
UV radiation
Ozone and climate change and feedback
Data management
Education, outreach and communication

ORACLE-O3 project has contributions from 67 research institutions in 22 countries. Spanish constribution is summarized in this presentation:

Spanish contribution to ORACLE-O3

Aerosol references and links

2007-12-19T12:31:00.000-08:00

My colleage Dra. Sandra Mogo from University of Beira Interior (Portugal) focuses her research on the nature and behavior of aerosols (optical properties, laboratory and field measurements, optical instrumentation, radiative forcing and modelization). Sandra has a close collaboration with the Atmospheric Optical Group from University of Valladolid (Spain).

Sandra's web-page contains two very interesting lists about aerosol science:

Valencia Anchor Station

2007-12-17T12:54:00.000-08:00

Valencia Anchor Station (VAS) is an automatic meteorological station equipped with a large number of instruments to carry out validation activities of remote sensing data and products . It is located at about 80 km from the city of Valencia (Spain) in a reasonably homogeneous and flat area of about 50x50 km2.

The main scientific objectives of the VAS are:

Definition of a large scale validation area for low-spatial resolution missions.
Definition and characterisation of a large scale reference pixel.
Study of scaling issues. Time Interpolation and Spatial Averaging.

VAS takes part in validation and calibration activities of satellite sensors corresponding to several missions such as EarthCARE (Earth Clouds, Aerosols and Radiation Explorer) and CERES (Clouds and the Earth’s Radiant Energy System).

More information in its web:

Valencia Anchor Station

WMO Sand and Dust Storm Warning System for Europe, Africa and Middle East

2007-12-13T12:31:00.000-08:00

Spain is currently implementing a WMO Regional Sand and Dust Storm Warning System Centre for Europe, Africa and Middle East. This Regional Centre aims to achieve three major objectives:

provide real-time information from a core-operational and quality controlled dust monitoring and forecasting system.

maintain a web portal with both research and near-real information and links to available dust forecasting and monitoring systems within the region.

implement a web-oriented modelling and observational historical data base available for case-study and climatological analysis.

The Spanish Antarctic base is already opened

2007-12-10T13:06:00.000-08:00

After many hard working days in the last couple of weeks, "Gabriel de Castilla" Antarctic Base is completely operative. At all, 14 Spaniards and 1 Mexican will stay during three months in this far place. My colleages Antonio Serrano (row of down, second by the left) and Maria Luisa Cancillo (row of above, second by the right) have already started their research works about the radiative budget in the permafrost (frozen ground) . Good Luck!!!!

GOME-2 Team

2007-12-07T10:02:00.000-08:00

I would like to write about the group within which I am currently doing a research stay. The GOME-2 Team at DLR belongs to Remote Sensing Technology Institute (IMF) . Its main research topics are related with the algorithm development in order to obtain total columns products of ozone, minor trace gases and cloud properties. These satellite products are generated at DLR in the framework of the Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M SAF).

The Global Ozone Monitoring Experiment-2 (GOME-2) is one of the new-generation European instruments carried on MetOp-A (launched in October 2006). It continues the long-term monitoring of atmospheric trace gases started by GOME on ERS-2 and SCIAMACHY on Envisat.

Arrival to Antarctica

2007-12-01T13:42:00.000-08:00

My colleages Antonio Serrano and María Luísa Cancillo from University of Extremadura have already arrived to Deception Island. The meteorological conditions have been quite unfavorable during The Drake passage, between Cape Horn and Antarctica. In addition, the "Gabriel de Castilla" Spanish Base has a lot of snow cover (about 2 meters). Thus, the instalation works will be very hard.

In the Base campaign dairy, there is current information about this antarctic expedition.

El Pais newspaper has published a broad information about the arrival to Antactican of this expedition.

Quadrennial Ozone Symposium

2007-11-28T13:52:00.000-08:00

The 2008 Quadrennial Ozone Symposium will take place in Tromsø, Norway, from 29 June to 5 July 2008. The main topics are:

Ozone depletion in a historical perspective

Observations – total ozone, vertical distribution, analysis and evaluation

UV changes

Tropospheric ozone – trends, precursors, emissions

Climate ozone interaction

Ozone recovery

More information in the symposium web:

QOS2008

Carlos Toledano

2007-11-17T03:11:00.000-08:00

I visited my colleague Dr. Carlos Toledano last week. He is currently doing a postdoctoral research stay at Meteorological Institute from University of Munich. He works together with Dr. Peter Koepke in the Radiation and Remote Sensing Group.

Carlos focuses his research on the study of atmospheric aerosols with optical methods. He did his Ph.D. thesis at Atmospheric Optics Group from University of Valladolid (Spain).

Antarctic Research

2007-11-14T08:55:00.000-08:00

The AIRE group of the University of Extremadura is also involved in Antarctic research. Thus, next week, María Luisa Cancillo and Antonio Serrano, members of this research group, will travel to Decepción Island to carry out research activities related to the energy balance of the permafrost. They will stay at the "Gabriel de Castilla" Spanish Antarctic Base for two months.

6rd Spanish-Portuguese Assembly of Geodesy and Geophysics

2007-11-10T00:09:00.000-08:00

The 6rd Spanish-Portuguese Assembly of Geodesy and Geophysics will be held the next February 2008 in Tomar (Portugal).

Information about topics, deadlines, etc, in the following link:

Spanish-Portuguese Assembly of Geodesy and Geophysics

Iberian Aerosols Measuments Network (RIMA)

2007-11-09T09:34:00.000-08:00

RIMA (Red Ibérica de Medida fotométrica de Aerosoles) Network is currently maded up of 15 Cimel photometer. This network is greatly expanded by collaborators from national institutes and universities from Spain and Portugal. RIMA Network is coordinated by University of Valladolid (Spain) and it is associated with AERONET network.

AIRE research group (University of Extremadura) is participating since 2004 with a Cimel photometer located at Cáceres.

More information about RIMA Network in its web (in Spanish):

RIMA Network

German Aerospace Center (DLR)

2007-11-04T01:08:00.000-07:00

Currently, I am a visiting scientist at Remote Sensing Technology Institute (IMF) at DLR in Wessling near to Munich (Germany). The research stay will last until the end of January 2008 and it focus on the ozone data comparison between GOME-2 satellite instrument and Brewer spectroradiometers in Iberian Peninsula.

This research stay is a continuation of a O3-SAF VS Activity carried out the past year which was summarized in this report:

Validation of total ozone GOME data with measurments of Spanish Brewer Network

More information in the following links:

O3-SAF Project

GOME-2 sensor

7th EMS Annual Meeting

2007-11-01T23:19:00.000-07:00

European Meteorological Society (EMS) Annual Meeting was held in San Lorenzo de El Escorial, Madrid, Spain from 1 to 5 October 2007. This event addressed a wide spectrum of scientific and application topics in atmospheric sciences – Atmosphere and the Water Cycle, Forecasting the Weather from one day to one year ahead, Climatology (under the auspices of ECSN) and Meteorology and Society.

In this meeting, Dr. Francisco Javier Acero belonging AIRE research group presented the following study:

Analysis of UV radiation values during a low ozone
episode over Exremadura (Spain) in January 2006

UV radiation conference in Davos

2007-11-01T22:48:00.000-07:00

To celebrate the 100th anniversary of the Physikalisch-Meteorologisches Observatorium Davos (PMOD/WRC), a conference dedicated to solar UV radiation research carried out in Davos (Switzerland) from 18 to 20 September 2007. The conference got together about 100 scientists interested in solar UV radiation, with topics ranging from measurements and modelling, to the influence of UV radiation on humans and climate.

Dr. Antonio Serrano belonging to AIRE Research Group (Extremadura University) participated in this interesting event and he presented the following works:

Calibration campaign of broad-band UV radiometer Arenosillo 2007

2007-11-01T01:19:00.000-07:00

The first Spanish calibration campaign of ultraviolet broad-band radiometer was carried out at the “El Arenosillo” INTA station in Huelva (Spain), from 20 August to 15 September 2007. This campaign was organized by Spanish Institute of Aerospace Technology (INTA) and University of Extremadura with the colaboration of Spanish Institute of Meteorology (INM).

In all, 22 broad-band UV instruments from 13 institutions took part in this important event.

Antón et al., 2007, Journal of Geophysical Research

2007-11-01T01:03:00.000-07:00

Total ozone mapping spectrometer retrievals of noon erythemal-CIE ultraviolet irradiance compared with Brewer ground-based measurements at El Arenosillo (southwestern Spain)

M. Anton, V.E. Cachorro, J.M. Vilaplana, N.A. Krotkov, A.Serrano, C. Toledano, B. de la Morena and J.R. Herman

Abstract: During the last decade, methods have been developed for estimating ultraviolet (UV) irradiance reaching the Earth’s surface using satellite-measured backscattered UV radiances. The aim of this work is to compare UV products (version 8), noon erythemal Commission Internationale de l'Eclairage (CIE)-UV irradiance (and daily CIE UV doses) from NASA Total Ozone Mapping Spectrometer (TOMS), with ground-based measurements from a well-calibrated Brewer spectrophotometer. This system is installed at the ESAt-“El Arenosillo” (Huelva) station, located in southwest Spain, near the Gulf of Cadiz, an area that is exposed to terrestrial Atlantic-Mediterranean air masses, with a high frequency (about 50%) of cloud-free days. The period analyzed was from 2000 to 2004, separated into two periods, 2000–2002 and 2003–2004, for comparative analysis. The reason for the two periods is the known calibration problem of Earth Probe-TOMS that became more pronounced by the end of 2002. The calibration errors are most important in the reflectivity and Aerosol Index TOMS data. Although the comparison results are slightly better for the first period, we do not observe major discrepancies during the second period; thus both periods were combined for final conclusions. Four different atmospheric conditions are tested in order to analyze the effects of clouds and aerosols on the differences between TOMS and Brewer data: all-sky, cloud-free with any aerosols, as well as with low and high aerosol loads. In general, under all sky conditions, TOMS overestimates the noon CIE irradiance by 7.5 ± 0.7% (daily CIE doses 8.3 ± 0.6%), but the most relevant is that the bias becomes negative for high values of TOMS reflectivity (thick clouds or high cloud optical depth) with a significant noise increase. Therefore the TOMS bias is higher for cloud-free days, 11.8 ± 0.2%, increasing with the aerosol optical depth, as measured by a colocated Cimel-AERONET Sun photometer. A high correlation between TOMS and Brewer CIE noon irradiances was observed when aerosol-binned data are considered, reaching R2=0.8.

Anton et al., 2007, Geophysical Research Letters

2007-11-01T00:27:00.000-07:00

Ozone mini-hole over southwestern Spain during January 2004: Influence over ultraviolet radiation

M. Antón, M.L. Cancillo, A. Serrano, J.M. Vaquero and J.A. García

Abstract: During the last decades, extremely low total ozone events of small spatial extension, named ozone mini-hole, have been reported in the Northern Hemisphere. A few ozone mini-hole episodes, which last only few days, were observed over southwestern Spain during 2004. In this work, these extreme events have been detected using TOMS satellite instrument. Additionally, the UV solar radiation was measured in three cities: Badajoz, Cáceres, and Plasencia. The most intensive episode occurred on 10 January 2004 when total ozone amount values decreased to 189–200 DU. These values represent a decrease greater than 33% with respect to the mean values registered in these cities during 1996–2005. In this paper, firstly we analyse the origin of the ozone mini-hole episode which is related to two atmospheric dynamics processes. Secondly, the influence of these extreme events on ultraviolet radiation recorded under cloud-free conditions in southwestern Spain is described. A great increase in UV erythemal radiation measurement was recorded on 10 January 2004, between 43% and 75% with respect to values measured on 10 January 2003 and 10 January 2005.

Toledano et al., 2006, Tellus B

2007-11-01T00:23:00.000-07:00

Aerosol optical depth at ALOMAR Observatory (Andøya, Norway) in summer 2002 and 2003

C. Toledano, V.E. Cachorro, A. Berjón, M. Sorribas, R. Vergaz, A. de Frutos, M. Antón and M. Gausa

Abstract: Two intensive campaigns were carried out by the Atmospheric Optics Group of Valladolid University (GOA-UVA) during summer 2002 and 2003 at ALOMAR station (Andøya island, Norway, 69°16′N, 16°00′E), allowing an aerosol characterization and classification in this coastal Arctic region during the summer. Aerosol measurements were performed with a Cimel sun photometer at the four nominal aerosol wavelengths 440 nm, 670 nm, 870 nm and 1020 nm. Spectral measurements in the range 300-1100 nm with a field spectroradiometer Licor-1800 were also performed during 2003, allowing a comparison with Cimel data. The agreement between both instruments is inside the current error for field aerosol optical depth retrieval, namely, 0.02. Although aerosol optical depth (AOD) at the nominal wavelength of 440 nm has an average value below 0.12, values range from 0.04 to 0.36. Derived Ångström alpha coefficient gives an average value about 1.6 (STD 0.2), meaning predominance of fine particles. These values do not fit the typical maritime aerosol characteristics. Continental and long-range transport air masses seem to influence this area, giving rise to mixed aerosols. Back trajectory analysis shows the predominance of Atlantic air masses with low AOD, while continental air masses show in general larger aerosol loading.

Serrano et al., 2006, Annales Geophysicae

2007-11-01T00:19:00.000-07:00

Daily and annual variations of erythemal ultraviolet radiation in Southwestern Spain

A. Serrano, M. Antón, M. L. Cancillo, V. L. Mateos

Abstract: The potential danger of ultraviolet (UV) radiation and its increasing levels at the Earth's surface due to ozone depletion have demanded worldwide representative measurements of UV radiation. This study presents four and one-half years of original records of high temporal resolution ultraviolet erythemal radiation (UVER) measured in Badajoz, Spain. Its principal aim is to statistically characterize the UVER magnitude and temporal variations, but also to address the interesting special cases of cloud-free and cloudy skies. In particular, the study reports reliable values of fundamental statistical indices, which can serve as relevant values for comparison with other studies and model results. Moreover, the daily and annual evolution of the main central moments of the distribution function are analyzed and interpreted in terms of the forcing and attenuation sources. The analysis focuses on two different temporal scales: hourly and daily values. Integrated hourly and daily data allow for the study of daily and annual variations of the fundamental statistical indices. All of them exhibit high symmetry with respect to solar noon and to certain dates near summer and winter solstices. The analysis shows the great influence of cloudiness in the distribution of UVER values. Thus, both daily and hourly UVER data present a slightly asymmetrical, left tailed, mesokurtic distribution for all months, except for summer, when the lack of clouds produces a leptokurtic distribution which is skewed to the left.

Casinière et al., 2005, Annales Geophysicae

2007-11-01T00:16:00.000-07:00

Comparative measurements of total ozone amount and aerosol optical depth during a campaign at El Arenosillo, Huelva, Spain

A. de La Casinière, V. Cachorro, I. Smolskaia, J. Lenoble, M. Sorribas, M. Houët, O. Massot, M. Antón and J. M. Vilaplana

Abstract: A one week field campaign took place in September 2002 at El Arenosillo, Spain. The objective was to compare total ozone column (TOC) and aerosol optical depth (AOD) from near ultraviolet to near infrared, measured by several Spanish and French instruments. Three spectroradiometers, Brewer, SPUV02, and LICOR, and a CIMEL photometer, have been used simultaneously and the results are presented for four clear days. TOC values are given by the Brewer instrument, and by SPUV02, using two different methods. The ground instruments compare satisfactorily (within 5 DU) and the values are consistent with TOMS data (within 10 DU).
AOD from the various instruments are compared at seven different wavelengths between 320 nm and 1020 nm: the agreement is very good at 350, 380, and 870 nm; at the four other wavelengths the difference is smaller than 0.03, which can be explained by a relative difference of 4% only between the calibrations of the various instruments. Larger AOD diurnal variations were observed at short wavelengths than in the visible and near infrared; this is most likely due to changes in aerosol size along the day, during the campaign.

Cancillo et al., 2005, Photochemistry and Photobiology

2007-11-01T00:09:00.000-07:00

An Improved Outdoor Calibration Procedure for Broadband Ultraviolet Radiometers

M.L. Cancillo, A. Serrano, M. Antón, J. A. García, J.M. Vilaplana and B. de la Morena

Abstract: This article aims at improving the broadband ultraviolet radiometer's calibration methodology. For this goal, three broadband radiometers are calibrated against a spectrophotometer of reference. Three different one-step calibration models are tested: ratio, first order and second order. The latter is proposed in order to adequately reproduce the high dependence on the solar zenith angle shown by the other two models and, therefore, to improve the calibration performance at high solar elevations. The proposed new second-order model requires no additional information and, thus, keeps the operational character of the one-step methodology. The models are compared in terms of their root mean square error and the most qualified is subsequently validated by comparing its predictions with the spectrophotometer measurements within an independent validation data subset. Results show that the best calibration is achieved by the second-order model, with a mean bias error and mean absolute bias error lower than 2.2 and 6.7%, respectively.

Cancillo et al., 2005, Physica Scripta

2007-11-01T00:06:00.000-07:00

Solar Global Radiation and Sunshine Duration in Extremadura (Spain)

M.L. Cancillo, A. Serrano, A. Ruíz, J.A. García, M. Antón and J.M. Vaquero

Abstract: This paper aims at analysing the relationship of solar global irradiation and sunshine duration at three stations in Extremadura (Spain) at a daily and monthly basis. Studying this dependence is of great interest since it allows to estimate solar irradiation in many stations where sunshine duration is measured and then, extend the number of locations with data, in order to plot reliable solar radiation spatial distributed maps. The mentioned relationship is investigated at both daily and monthly basis, by fitting the Ångström-Prescott model by regression techniques. The correlation coefficients show notably high values for the three locations, suggesting the suitability of the model for the measured data. Moreover, the regression coefficients are in agreement with those obtained in other works for different locations in the Iberian Peninsula. In the daily analysis, it is also found that residuals show a smooth annual behaviour and, therefore, Ångström-Prescott model was fitted for each calendar month separately. The annual evolution of the regression coefficients and the atmospheric transparency index is analysed and compared for the three stations of measurements.

2005

2007-10-31T13:01:00.000-07:00

M. Antón, M. L. Cancillo, A. Serrano and J. A. García, (2005), A Multiple Regression Analysis Between UV Radiation Measurements at Badajoz and Ozone, Reflectivity and Aerosols Estimated by TOMS, Physica Scripta, T118, 21-23. [Abstract]

M. L. Cancillo, A. Serrano, A. Ruiz, J. A. García, M. Antón and J. M. Vaquero, (2005), Solar Global Radiation and Sunshine Duration in Extremadura (Spain), Physica Scripta, T118, 24-28. [Abstract]