Articles | Volume 5, issue 1
https://doi.org/10.5194/gi-5-17-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/gi-5-17-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
05 Feb 2016
Research article |
| 05 Feb 2016
Removing low-frequency artefacts from Datawell DWR-G4 wave buoy measurements
J.-V. Björkqvist
CORRESPONDING AUTHOR
Finnish Meteorological Institute, Helsinki, Finland
H. Pettersson
Finnish Meteorological Institute, Helsinki, Finland
L. Laakso
Finnish Meteorological Institute, Helsinki, Finland
Unit for Environmental Sciences and Management, North-West University, Potchefstroom, Republic of South Africa
K. K. Kahma
Finnish Meteorological Institute, Helsinki, Finland
H. Jokinen
Finnish Meteorological Institute, Helsinki, Finland
P. Kosloff
Finnish Meteorological Institute, Helsinki, Finland
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Jan-Victor Björkqvist, Heidi Pettersson, and Kimmo K. Kahma
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Tracey Leah Laban, Pieter Gideon van Zyl, Johan Paul Beukes, Ville Vakkari, Kerneels Jaars, Nadine Borduas-Dedekind, Miroslav Josipovic, Anne Mee Thompson, Markku Kulmala, and Lauri Laakso
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Ulpu Leijala, Jan-Victor Björkqvist, Milla M. Johansson, Havu Pellikka, Lauri Laakso, and Kimmo K. Kahma
Nat. Hazards Earth Syst. Sci., 18, 2785–2799, https://doi.org/10.5194/nhess-18-2785-2018, https://doi.org/10.5194/nhess-18-2785-2018, 2018
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The coastal flooding risks based on the combined effect of sea level variations and wind-generated waves are estimated for the present, 2050 and 2100. The variability of the wave conditions between the two case study locations in the Helsinki archipelago leads to a difference in the safe building levels of up to 1 m. The rising mean sea level in the Gulf of Finland and the uncertainty of the associated scenarios contribute to the flooding risks notably in 2100.
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Atmos. Chem. Phys., 18, 14737–14756, https://doi.org/10.5194/acp-18-14737-2018, https://doi.org/10.5194/acp-18-14737-2018, 2018
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Atmospheric aerosols have diverse effects on air quality, human health, and global climate. One important source of aerosols is their formation via nucleation and growth in the atmosphere. We have analyzed long-term observations of regional new particle formation events around the globe and provide a comprehensive view on the characteristics of this phenomenon in diverse environments. The results are useful in developing more realistic representation of atmospheric aerosols in global models.
Martti Honkanen, Juha-Pekka Tuovinen, Tuomas Laurila, Timo Mäkelä, Juha Hatakka, Sami Kielosto, and Lauri Laakso
Atmos. Meas. Tech., 11, 5335–5350, https://doi.org/10.5194/amt-11-5335-2018, https://doi.org/10.5194/amt-11-5335-2018, 2018
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The exchange rate of carbon dioxide (CO2) between the atmosphere and the sea is typically small compared to the fluxes observed in the terrestrial ecosystems, causing technical challenges for the measurements of the CO2 sea–air fluxes. In this paper, we examine CO2 sea–air flux measurements carried out on a fixed station on an island. The problems generated by water vapor interference and unmet theoretical assumptions of the eddy covariance method are addressed.
Lauri Laakso, Santtu Mikkonen, Achim Drebs, Anu Karjalainen, Pentti Pirinen, and Pekka Alenius
Ocean Sci., 14, 617–632, https://doi.org/10.5194/os-14-617-2018, https://doi.org/10.5194/os-14-617-2018, 2018
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Meteorological observations at Utö Atmospheric and Marine Research Station, the Baltic Sea, started in 1881 and seawater temperature and salinity observations in 1900. Based on the dataset of more than 100 years of observations, we see an increase in atmospheric temperature after the 1980s, in line with reduced sea ice cover. We also found an increase in seawater temperatures, modulated by changes in salinities. The results indicate that the climate at Utö may have shifted into a new phase.
Jan-Victor Björkqvist, Laura Tuomi, Niko Tollman, Antti Kangas, Heidi Pettersson, Riikka Marjamaa, Hannu Jokinen, and Carl Fortelius
Nat. Hazards Earth Syst. Sci., 17, 1653–1658, https://doi.org/10.5194/nhess-17-1653-2017, https://doi.org/10.5194/nhess-17-1653-2017, 2017
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We studied the highest wave events in the Baltic Sea using wave measurements available since 1996. Going beyond classifying them based solely on the maximum wave height, we found that they can be divided into two groups based on, for example, the length of the storm. Two of the severest storms show different behaviour, with the most recent (in 2017) being the longest on record. We hope this more in-depth description of the storms will aid in the issuing of warnings for extreme wave conditions.
Kgaugelo Euphinia Chiloane, Johan Paul Beukes, Pieter Gideon van Zyl, Petra Maritz, Ville Vakkari, Miroslav Josipovic, Andrew Derick Venter, Kerneels Jaars, Petri Tiitta, Markku Kulmala, Alfred Wiedensohler, Catherine Liousse, Gabisile Vuyisile Mkhatshwa, Avishkar Ramandh, and Lauri Laakso
Atmos. Chem. Phys., 17, 6177–6196, https://doi.org/10.5194/acp-17-6177-2017, https://doi.org/10.5194/acp-17-6177-2017, 2017
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This paper presents atmospheric black carbon (BC) data collected in South Africa (SA). In general, BC level were higher than in the developed world. At one site, five sources were identified, with household combustion as well as savannah and grassland fires the most significant sources during winter and spring, while coal-fired power stations, pyrometallurgical smelters and traffic contributed year round.
Andrew D. Venter, Pieter G. van Zyl, Johan P. Beukes, Micky Josipovic, Johan Hendriks, Ville Vakkari, and Lauri Laakso
Atmos. Chem. Phys., 17, 4251–4263, https://doi.org/10.5194/acp-17-4251-2017, https://doi.org/10.5194/acp-17-4251-2017, 2017
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Size-resolved trace metal concentrations were determined at a regional background site impacted by the major pollutant source regions in the interior of South Africa, which include a region holding a large number of pyrometallurgical smelters. ≥70% of trace metal species were in the smaller size fractions, indicating the influence of industrial activities, while the influence of wind-blown dust was reflected in the PM2.5–10 size fraction. Annual average Ni and As exceeded European standards.
Matti Räsänen, Mika Aurela, Ville Vakkari, Johan P. Beukes, Juha-Pekka Tuovinen, Pieter G. Van Zyl, Miroslav Josipovic, Andrew D. Venter, Kerneels Jaars, Stefan J. Siebert, Tuomas Laurila, Janne Rinne, and Lauri Laakso
Biogeosciences, 14, 1039–1054, https://doi.org/10.5194/bg-14-1039-2017, https://doi.org/10.5194/bg-14-1039-2017, 2017
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This study presents measurements of carbon dioxide exchange between the atmosphere and a grazed savanna grassland ecosystem for 3 years. We find that the yearly variation in carbon dioxide balance is largely determined by the changes in the early wet season balance (September to November) and in the mid-growing season balance (December to January).
Kerneels Jaars, Pieter G. van Zyl, Johan P. Beukes, Heidi Hellén, Ville Vakkari, Micky Josipovic, Andrew D. Venter, Matti Räsänen, Leandra Knoetze, Dirk P. Cilliers, Stefan J. Siebert, Markku Kulmala, Janne Rinne, Alex Guenther, Lauri Laakso, and Hannele Hakola
Atmos. Chem. Phys., 16, 15665–15688, https://doi.org/10.5194/acp-16-15665-2016, https://doi.org/10.5194/acp-16-15665-2016, 2016
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Biogenic volatile organic compounds (BVOCs) – important in tropospheric ozone and secondary organic aerosol formation – were measured at a savannah grassland in South Africa. Results presented are the most extensive for this type of landscape. Compared to other parts of the world, monoterpene levels were similar, while very low isoprene levels led to significantly lower total BVOC levels. BVOC levels were an order of magnitude lower compared to anthropogenic VOC levels measured at Welgegund.
Vasco M. N. C. S. Vieira, Pavel Jurus, Emanuela Clementi, Heidi Pettersson, and Marcos Mateus
Geosci. Model Dev. Discuss., https://doi.org/10.5194/gmd-2016-273, https://doi.org/10.5194/gmd-2016-273, 2016
Revised manuscript has not been submitted
V. M. N. C. S. Vieira, E. Sahlée, P. Jurus, E. Clementi, H. Pettersson, and M. Mateus
Biogeosciences Discuss., https://doi.org/10.5194/bgd-12-15901-2015, https://doi.org/10.5194/bgd-12-15901-2015, 2015
Manuscript not accepted for further review
V. M. N. C. S. Vieira, E. Sahlée, P. Jurus, E. Clementi, H. Pettersson, and M. Mateus
Biogeosciences Discuss., https://doi.org/10.5194/bgd-12-15925-2015, https://doi.org/10.5194/bgd-12-15925-2015, 2015
Manuscript not accepted for further review
F. Kuik, A. Lauer, J. P. Beukes, P. G. Van Zyl, M. Josipovic, V. Vakkari, L. Laakso, and G. T. Feig
Atmos. Chem. Phys., 15, 8809–8830, https://doi.org/10.5194/acp-15-8809-2015, https://doi.org/10.5194/acp-15-8809-2015, 2015
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The numerical model WRF-Chem is used to estimate the contribution of anthropogenic emissions to BC, aerosol optical depth and atmospheric heating rates over southern Africa. An evaluation of the model with observational data including long-term BC measurements shows that the basic meteorology is reproduced reasonably well but simulated near-surface BC concentrations are underestimated by up to 50%. It is found that up to 100% of the BC in highly industrialized regions is of anthropogenic origin.
E. Giannakaki, A. Pfüller, K. Korhonen, T. Mielonen, L. Laakso, V. Vakkari, H. Baars, R. Engelmann, J. P. Beukes, P. G. Van Zyl, M. Josipovic, P. Tiitta, K. Chiloane, S. Piketh, H. Lihavainen, K. E. J. Lehtinen, and M. Komppula
Atmos. Chem. Phys., 15, 5429–5442, https://doi.org/10.5194/acp-15-5429-2015, https://doi.org/10.5194/acp-15-5429-2015, 2015
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In this study we summarize 1 year of Raman lidar observations over South Africa. The analyses of lidar measurements presented here could assist in bridging existing gaps in the knowledge of vertical distribution of aerosols above South Africa, since limited long-term data of this type are available for this region. For the first time, we have been able to cover the full seasonal cycle on geometrical characteristics and optical properties of free tropospheric aerosol layers in the region.
A.-M. Sundström, A. Nikandrova, K. Atlaskina, T. Nieminen, V. Vakkari, L. Laakso, J. P. Beukes, A. Arola, P. G. van Zyl, M. Josipovic, A. D. Venter, K. Jaars, J. J. Pienaar, S. Piketh, A. Wiedensohler, E. K. Chiloane, G. de Leeuw, and M. Kulmala
Atmos. Chem. Phys., 15, 4983–4996, https://doi.org/10.5194/acp-15-4983-2015, https://doi.org/10.5194/acp-15-4983-2015, 2015
J. Backman, A. Virkkula, V. Vakkari, J. P. Beukes, P. G. Van Zyl, M. Josipovic, S. Piketh, P. Tiitta, K. Chiloane, T. Petäjä, M. Kulmala, and L. Laakso
Atmos. Meas. Tech., 7, 4285–4298, https://doi.org/10.5194/amt-7-4285-2014, https://doi.org/10.5194/amt-7-4285-2014, 2014
K. Jaars, J. P. Beukes, P. G. van Zyl, A. D. Venter, M. Josipovic, J. J. Pienaar, V. Vakkari, H. Aaltonen, H. Laakso, M. Kulmala, P. Tiitta, A. Guenther, H. Hellén, L. Laakso, and H. Hakola
Atmos. Chem. Phys., 14, 7075–7089, https://doi.org/10.5194/acp-14-7075-2014, https://doi.org/10.5194/acp-14-7075-2014, 2014
K. Korhonen, E. Giannakaki, T. Mielonen, A. Pfüller, L. Laakso, V. Vakkari, H. Baars, R. Engelmann, J. P. Beukes, P. G. Van Zyl, A. Ramandh, L. Ntsangwane, M. Josipovic, P. Tiitta, G. Fourie, I. Ngwana, K. Chiloane, and M. Komppula
Atmos. Chem. Phys., 14, 4263–4278, https://doi.org/10.5194/acp-14-4263-2014, https://doi.org/10.5194/acp-14-4263-2014, 2014
P. Tiitta, V. Vakkari, P. Croteau, J. P. Beukes, P. G. van Zyl, M. Josipovic, A. D. Venter, K. Jaars, J. J. Pienaar, N. L. Ng, M. R. Canagaratna, J. T. Jayne, V.-M. Kerminen, H. Kokkola, M. Kulmala, A. Laaksonen, D. R. Worsnop, and L. Laakso
Atmos. Chem. Phys., 14, 1909–1927, https://doi.org/10.5194/acp-14-1909-2014, https://doi.org/10.5194/acp-14-1909-2014, 2014
A. I. Partanen, A. Laakso, A. Schmidt, H. Kokkola, T. Kuokkanen, J.-P. Pietikäinen, V.-M. Kerminen, K. E. J. Lehtinen, L. Laakso, and H. Korhonen
Atmos. Chem. Phys., 13, 12059–12071, https://doi.org/10.5194/acp-13-12059-2013, https://doi.org/10.5194/acp-13-12059-2013, 2013
A. Hirsikko, V. Vakkari, P. Tiitta, J. Hatakka, V.-M. Kerminen, A.-M. Sundström, J. P. Beukes, H. E. Manninen, M. Kulmala, and L. Laakso
Atmos. Chem. Phys., 13, 5523–5532, https://doi.org/10.5194/acp-13-5523-2013, https://doi.org/10.5194/acp-13-5523-2013, 2013
V. Vakkari, J. P. Beukes, H. Laakso, D. Mabaso, J. J. Pienaar, M. Kulmala, and L. Laakso
Atmos. Chem. Phys., 13, 1751–1770, https://doi.org/10.5194/acp-13-1751-2013, https://doi.org/10.5194/acp-13-1751-2013, 2013
L. Riuttanen, M. Dal Maso, G. de Leeuw, I. Riipinen, L. Sogacheva, V. Vakkari, L. Laakso, and M. Kulmala
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acpd-13-4289-2013, https://doi.org/10.5194/acpd-13-4289-2013, 2013
Revised manuscript has not been submitted
J. Leppä, S. Gagné, L. Laakso, H. E. Manninen, K. E. J. Lehtinen, M. Kulmala, and V.-M. Kerminen
Atmos. Chem. Phys., 13, 463–486, https://doi.org/10.5194/acp-13-463-2013, https://doi.org/10.5194/acp-13-463-2013, 2013
A.-P. Hyvärinen, V. Vakkari, L. Laakso, R. K. Hooda, V. P. Sharma, T. S. Panwar, J. P. Beukes, P. G. van Zyl, M. Josipovic, R. M. Garland, M. O. Andreae, U. Pöschl, and A. Petzold
Atmos. Meas. Tech., 6, 81–90, https://doi.org/10.5194/amt-6-81-2013, https://doi.org/10.5194/amt-6-81-2013, 2013
V.-M. Kerminen, M. Paramonov, T. Anttila, I. Riipinen, C. Fountoukis, H. Korhonen, E. Asmi, L. Laakso, H. Lihavainen, E. Swietlicki, B. Svenningsson, A. Asmi, S. N. Pandis, M. Kulmala, and T. Petäjä
Atmos. Chem. Phys., 12, 12037–12059, https://doi.org/10.5194/acp-12-12037-2012, https://doi.org/10.5194/acp-12-12037-2012, 2012
Related subject area
Ocean instruments
Glider observations of thermohaline staircases in the tropical North Atlantic using an automated classifier
Continuous in situ measurement of dissolved methane in Lake Kivu using a membrane inlet laser spectrometer
A comprehensive data quality evaluation method for the currents of marine controlled-source electromagnetic transmitters based on the analytic hierarchy process
Evaluations of an ocean bottom electro-magnetometer and preliminary results offshore NE Taiwan
Simple, affordable, and sustainable borehole observatories for complex monitoring objectives
Drilling cores on the sea floor with the remote-controlled sea floor drilling rig MeBo
Callum Rollo, Karen J. Heywood, and Rob A. Hall
Geosci. Instrum. Method. Data Syst., 11, 359–373, https://doi.org/10.5194/gi-11-359-2022, https://doi.org/10.5194/gi-11-359-2022, 2022
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Using an underwater buoyancy-powered autonomous glider, we collected profiles of temperature and salinity from the ocean north-east of Barbados. Most of the temperature and salinity profiles contained staircase-like structures of alternating constant values and large gradients. We wrote an algorithm to identify these staircases. We hypothesise that these staircases are prevented from forming where background gradients in temperature and salinity are too great.
Roberto Grilli, François Darchambeau, Jérôme Chappellaz, Ange Mugisha, Jack Triest, and Augusta Umutoni
Geosci. Instrum. Method. Data Syst., 9, 141–151, https://doi.org/10.5194/gi-9-141-2020, https://doi.org/10.5194/gi-9-141-2020, 2020
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We report the results from the deployment of a newly developed in situ sensor for dissolved gas measurements. Its adaptation to high gas concentrations and dissolved gas pressures was proven. The campaign leads to a first continuous profile of methane on the first 150 m and allowed us to compare the data with previous measurements. The fast response of the instrument makes this technique a good candidate for regular monitoring of those type of lakes, for anticipating disastrous gas eruptions.
Rui Yang, Meng Wang, Gongxiang Wang, Ming Deng, Jianen Jing, and Xiancheng Li
Geosci. Instrum. Method. Data Syst., 9, 69–77, https://doi.org/10.5194/gi-9-69-2020, https://doi.org/10.5194/gi-9-69-2020, 2020
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An electromagnetic transmitter sends an electromagnetic wave to the seabed; the receiver located on the seafloor receives the electromagnetic wave which carries the information of the geosphere.
In this paper, an algorithm is proposed to improve the current quality of marine electromagnetic transmitters. It has an anomaly detection function for the unstable part of the transmitting current. Our results show that the instability of transmitting-current data can cause obvious anomalies.
Ching-Ren Lin, Chih-Wen Chiang, Kuei-Yi Huang, Yu-Hung Hsiao, Po-Chi Chen, Hsu-Kuang Chang, Jia-Pu Jang, Kun-Hui Chang, Feng-Sheng Lin, Saulwood Lin, and Ban-Yuan Kuo
Geosci. Instrum. Method. Data Syst., 8, 265–276, https://doi.org/10.5194/gi-8-265-2019, https://doi.org/10.5194/gi-8-265-2019, 2019
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The first stage of field experiments involving the design and construction of a low power-consumption ocean bottom electro-magnetometer (OBEM) has been completed: this can be deployed more than 180 d on the seafloor with a time drift of less than 0.95 ppm. We found that the inclinations and magnetic data of the OBEM varied with two observed earthquakes when compared to the OBS data. The potential fields of the OBEM were slightly, but not obviously, affected by the earthquakes.
A. Kopf, T. Freudenthal, V. Ratmeyer, M. Bergenthal, M. Lange, T. Fleischmann, S. Hammerschmidt, C. Seiter, and G. Wefer
Geosci. Instrum. Method. Data Syst., 4, 99–109, https://doi.org/10.5194/gi-4-99-2015, https://doi.org/10.5194/gi-4-99-2015, 2015
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Seafloor drill rigs are remotely operated systems that provide a cost-effective means to recover sedimentary records of the upper sub-seafloor deposits. Recent increases in their payload included downhole logging tools or autoclave coring systems. Here we report on another milestone in using seafloor rigs: the development and installation of shallow borehole observatories for the MARUM-MeBo seafloor drill developed at University of Bremen, Germany.
T. Freudenthal and G. Wefer
Geosci. Instrum. Method. Data Syst., 2, 329–337, https://doi.org/10.5194/gi-2-329-2013, https://doi.org/10.5194/gi-2-329-2013, 2013
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Short summary
We identified a previously unknown artefact in the Datawell DWR-G4 wave buoy, which measures the GPS signal to resolve surface water waves. The artefact interferes with the part of the measurements containing information about the longer waves and must be removed to obtain accurate readings. We presented a correction method and found it to be accurate based on a comparison to measurements from a larger wave buoy that measures the movements of the device without using the GPS signal.
We identified a previously unknown artefact in the Datawell DWR-G4 wave buoy, which measures the...
