Integrated water vapor over the Arctic: Comparison between radiosondes and sun photometer observations

Producción CientíficaThe amplification of global warming because of the feedbacks associated with the increase in atmospheric moisture and the decrease in sea ice and snow cover in the Arctic is currently the focus of scientists, policy makers and society. The amplification of global warming is the response to increases in precipitation originally caused by climate change. Arctic predominant increases in specific humidity and precipitation have been documented by observations. In comparison, evapotranspiration in the Arctic is poorly known, in part, because the spatial and temporal sparsity of accurate in situ and remote sensing observations. Although more than 20 observations sites in the Arctic are available, where AERONET sun photometer integrated water vapor (IWV) measurements have been conducted, that information have been barely used. Here, we present a comparison of IWV observations from radiosondes and AERONET sun photometers at ten sites located across the Arctic with the goal to document the feasibility of that set of observations to contribute to the ongoing and future research on polar regions. Sun photometer IWV observations are averaged for three-time windows; 30 min, 6 and 24 h. The predominant dry bias of AERONET IWV observations with respect to radiosondes, identified at tropical and midlatitudes, is also present in the Arctic. The statistics of the comparison show robust results at eight of the ten sites, with precision and accuracy magnitudes below 8 and 2% respectively. The possible causes of the less robust results at the other two sites are discussed. In addition, the impact of selecting other temporal coincidence windows in the average sun photometer IWV used in the comparison were tested. Auto-correlation in diurnal sun photometer IWV could produce appreciable bias in the statistics used for the comparison. We suggest using only one pair of values per day, consisting in the daily mean IWV sun photometer and the IWV radiosonde observation value. This feature should be valid also for comparison of IWV from sun photometer and other instruments. Maximum 10% error level of IWV from sun photometer observations, when compared with radiosondes, have been found for the Arctic. It is in the same order of magnitude than at tropical and middle latitudes locations. It has been demonstrated the feasibility of AERONET IWV observations in the Arctic for research on this variable. AERONET standard instruments and its centralized-standard processing algorithm allow its IWV observations to be considered a relative standard dataset for the re-calibration of other instrumental IWV observations assuming radiosondes as the absolute standard dataset.Ministerio de Ciencia, Innovación y Universidades (grant RTI2018-097864-B-I00)Junta de Castilla y León (grant VA227P20)Junta de Extremadura - Fondo Europeo de Desarrollo Regional (grant GR21080 and project IB18092

LALINET: The First Latin American–Born Regional Atmospheric Observational Network

Sustained and coordinated efforts of lidar teams in Latin America at the beginning of the 21st century have built LALINET (Latin American Lidar NETwork), the only observational network in Latin America created by the agreement and commitment of Latin American scientists. They worked with limited funding but an abundance of enthusiasm and commitment toward their joint goal. Before LALINET, there were a few pioneering lidar stations operating in Latin America, described briefly here. Bi-annual Latin American Lidar Workshops, held from 2001 to the present, supported both the development of the regional lidar community and LALINET. At those meetings, lidar researchers from Latin America meet to conduct regular scientific and technical exchanges among themselves and with experts from the rest of the world. Regional and international scientific cooperation has played an important role for the development of both the individual teams and the network. The current LALINET status and activities are described, emphasizing the processes of standardization of the measurements, methodologies, calibration protocols, and retrieval algorithms. Failures and successes achieved in the buildup of LALINET are presented. In addition, the first LALINET joint measurement campaign and a set of aerosol extinction profile measurements obtained from the aerosol plume produced by the Calbuco volcano eruption on April 22, 2015, are described and discussed.Fil: Antuña Marrero, Juan Carlos. Centro Meteorológico de Camagüey; CubaFil: Landulfo, Eduardo. Instituto de Pesquisas Energéticas e Nucleares; BrasilFil: Estevan, René. Centro Meteorológico de Camagüey; CubaFil: Barja, Boris. Centro Meteorológico de Camagüey; Cuba. Universidade de Sao Paulo; BrasilFil: Robock, Alan. State University of New Jersey; Estados UnidosFil: Wolfram, Elian Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Científicas y Técnicas para la Defensa. Centro de Investigación en Láseres y Aplicaciones; ArgentinaFil: Ristori, Pablo Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Científicas y Técnicas para la Defensa. Centro de Investigación en Láseres y Aplicaciones; ArgentinaFil: Clemesha, Barclay. Upper Atmosphere Research Group; BrasilFil: Zaratti, Francesco. Universidad Mayor de San Andrés; BoliviaFil: Forno, Ricardo. Universidad Mayor de San Andrés; BoliviaFil: Armandillo, Errico. ESTEC; Países BajosFil: Bastidas, Álvaro E.. Universidad Nacional de Colombia. Sede Medellin; ColombiaFil: de Frutos Baraja, Ángel Máximo. Universidad de Valladolid; EspañaFil: Whiteman, David N.. National Aeronautics and Space Administration; Estados UnidosFil: Quel, Eduardo Jaime. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Científicas y Técnicas para la Defensa. Centro de Investigación en Láseres y Aplicaciones; ArgentinaFil: Barbosa, Henrique M. J.. Universidade de Sao Paulo; BrasilFil: Lopes, Fabio. Comissao Nacional de Energia Nuclear. Centro de Lasers e Aplicacoes. Instituto de Pesquisas Energeticas e Nucleares.; BrasilFil: Montilla-Rosero, Elena. Universidad de Concepción; Chile. Universidad Escuela de Administración, Finanzas e Instituto Tecnológico; ColombiaFil: Guerrero Rascado, Juan L.. Comissao Nacional de Energia Nuclear. Centro de Lasers e Aplicacoes. Instituto de Pesquisas Energeticas e Nucleares.; Brasil. Universidad de Granada; Españ

Lidar Observations in South America. Part I - Mesosphere and Stratosphere

South America covers a large area of the globe and plays a fundamental function in its climate change, geographical features, and natural resources. However, it still is a developing area, and natural resource management and energy production are far from a sustainable framework, impacting the air quality of the area and needs much improvement in monitoring. There are significant activities regarding laser remote sensing of the atmosphere at different levels for different purposes. Among these activities, we can mention the mesospheric probing of sodium measurements and stratospheric monitoring of ozone, and the study of wind and gravity waves. Some of these activities are long-lasting and count on the support from the Latin American Lidar Network (LALINET). We intend to pinpoint the most significant scientific achievements and show the potential of carrying out remote sensing activities in the continent and show its correlations with other earth science connections and synergies. In Part I of this chapter, we will present an overview and significant results of lidar observations in the mesosphere and stratosphere. Part II will be dedicated to tropospheric observations

Stratospheric aerosol - Observations, processes, and impact on climate

Interest in stratospheric aerosol and its role in climate have increased over the last decade due to the observed increase in stratospheric aerosol since 2000 and the potential for changes in the sulfur cycle induced by climate change. This review provides an overview about the advances in stratospheric aerosol research since the last comprehensive assessment of stratospheric aerosol was published in 2006. A crucial development since 2006 is the substantial improvement in the agreement between in situ and space-based inferences of stratospheric aerosol properties during volcanically quiescent periods. Furthermore, new measurement systems and techniques, both in situ and space based, have been developed for measuring physical aerosol properties with greater accuracy and for characterizing aerosol composition. However, these changes induce challenges to constructing a long-term stratospheric aerosol climatology. Currently, changes in stratospheric aerosol levels less than 20% cannot be confidently quantified. The volcanic signals tend to mask any nonvolcanically driven change, making them difficult to understand. While the role of carbonyl sulfide as a substantial and relatively constant source of stratospheric sulfur has been confirmed by new observations and model simulations, large uncertainties remain with respect to the contribution from anthropogenic sulfur dioxide emissions. New evidence has been provided that stratospheric aerosol can also contain small amounts of nonsulfate matter such as black carbon and organics. Chemistry-climate models have substantially increased in quantity and sophistication. In many models the implementation of stratospheric aerosol processes is coupled to radiation and/or stratospheric chemistry modules to account for relevant feedback processes

Lidar Observations in South America. Part II - Troposphere

In Part II of this chapter, we intend to show the significant advances and results concerning aerosols’ tropospheric monitoring in South America. The tropospheric lidar monitoring is also supported by the Latin American Lidar Network (LALINET). It is concerned about aerosols originating from urban pollution, biomass burning, desert dust, sea spray, and other primary sources. Cloud studies and their impact on radiative transfer using tropospheric lidar measurements are also presented

Efecto radiativo de la erupción del Monte Pinatubo sobre Cuba

Los aerosoles estratosféricos de origen volcánico provocan una importante y duradera perturbación en el balance radiativo del sistema tierra-atmósfera, que consecuentemente, induce una respuesta del sistema climático. En el presente trabajo se muestran, por primera vez en Cuba, las perturbaciones provocadas por la erupción del volcán Monte Pinatubo en los flujos radiativos y la razón de calentamiento sobre Camagüey. Para ello se han empleado mediciones de la nube de aerosoles estratosféricos realizadas en la Estación Lidar de Camagüey y un código radiativo desarrollado por el Laboratorio Geofísico de Dinámica de los fluidos (GFDL, por sus siglas en inglés), adaptado a nuestras condiciones. La distribución espacio temporal del forzamiento radiativo, para diferentes bandas espectrales por la presencia de la nube de aerosoles del Pinatubo, evidencia el calentamiento de la estratósfera, así como el enfriamiento de la troposfera sobre Camagüey. Se muestra la respuesta de la estratósfera ante la presencia de aerosoles de origen volcánico en esta región de la atmósfera, mediante el comportamiento diurno de la razón de calentamiento en condiciones de máxima y mínima concentración de aerosoles, enero de 1992 y diciembre de 1993 respectivamente. El forzamiento radiativo por aerosoles supera los -9 W/(metro cuadrado) y los valores máximos de perturbación de la razón de calentamiento llegan a 0,1 K/d

Solar Radiation Climatology in Camagüey, Cuba (1981–2016)

The transition to renewable energies is an unavoidable step to guarantee a peaceful and sustainable future for humankind. Although solar radiation is one of the main sources of renewable energy, there are broad regions of the planet where it has not been characterized appropriately to provide the necessary information for regional and local planning and design of the different solar powered systems. The Caribbean, and Cuba in particular, lacked until very recently at least one long-term series of surface solar radiation measurements. Here we present the first long-term records of solar radiation for this region. Solar radiation measurements manually conducted and recorded on paper were rescued, reprocessed and quality controlled to develop the solar radiation climatology at the Actinometrical Station of Camagüey, in Cuba (21.422°N; 77.850°W; 122 m a.s.l.) for the period 1981–2016. The diurnal cycle based on the average hourly values of the global, direct and diffuse horizontal variables for the entire period have been determined and analyzed showing the dependence on solar zenith angle (SZA) and clouds. The annual cycle of global solar component given by the mean monthly daily values presents two maxima, one in April and another one in July with values of 5.06 and 4.91 kWh m−2, respectively (18.23 and 17.67 MJ m−2 per day for insolation), and the minimum in December (3.15 kWh m−2 or 11.33 MJ m−2). The maxima are governed by the direct solar components and are modulated by cloudiness. Both, diurnal and annual cycles of the diffuse solar component show a smoothed bell shaped behavior. In general solar radiation at this station presents a strong influence of clouds, with little seasonal variation but with higher values during the rainy season. Daily global radiation annual averages showed its maximum value in the year 1983, with 17.45 MJ m−2 explained by very low cloudiness this year, and the minimum value was reported in 2009 with a value of 12.43 MJ m−2 that could not explained by the cloud coverage or the aerosols optical depths registered that year. The effects of the 1982 El Chichón and 1991 Mount Pinatubo volcanic eruptions on the solar radiation variables at Camagüey are also shown and discussed. The results achieved in this study shown the characteristics of solar radiation in this area and their potential for solar power applications

Modelled and observed sea surface temperature trends for the Caribbean and Antilles

ABSTRACT: The ocean occupies 95% of the Caribbean's area and plays a leading role in the region's climate, thus making the sea surface temperature (SST) a very important regional climate index. This, in conjunction with the lack of a regionally consistent, quality-controlled surface temperature dataset increases the scientific value of using SST to characterize the regional climate and its trends. This study determines the magnitudes of the long-term SST trends in the Wider Caribbean (WC) and the Antilles. We overcome the presence of discontinuity points in the SST time series using the change point statistical technique. Annual mean SST trends combining the subperiods 1906-1969 and 1972-2005 are 1.32 ± 0.41 ∘ C per century for the Antilles and 1.08 ± 0.32 ∘ C per century for the WC. For the same regions during the subperiod 1972-2005, the corresponding trends are 1.41 ± 0.68 ∘ C per century and 1.18 ± 0.49 ∘ C per century, illustrating the warming intensification during the last four decades. A significant correlation is found between the SSTs in the Caribbean and Atlantic Multidecadal Oscillation (AMO) index, suggesting a potential link between Caribbean SSTs and the mechanisms governing the Atlantic basin-wide SSTs. Finally, the capabilities of two state-of-the-art coupled climate models, the Norwegian Earth System Model (NorESM1-M) and the Bergen Climate Model (BCM), to simulate SST in the Caribbean were tested. Both models produce an adequate simulation of the annual mean SST anomalies and SST seasonal cycle for the WC and the Antilles. The simulated annual and monthly mean SSTs are colder in the two models compared to the observations, a common feature among the majority of general circulation models participating in the Coupled Model Intercomparison Project Phase 5. However, despite these minor deficiencies both BCM and NorESM1-M are considered adequate for conducting SST simulations relevant for future climate change research in the Caribbean

Synergetic Aerosol Layer Observation After the 2015 Calbuco Volcanic Eruption Event

On 22 April 2015, the Calbuco volcano in Chile (Lat: 41.33 ∘ S, Long: 72.62 ∘ W) erupted after 43 years of inactivity followed by a great amount of aerosol injection into the atmosphere. The pyroclastic material dispersed into the atmosphere posed a potential threat to aviation traffic and air quality over affected a large area. The plumes and debris spread from its location to Patagonian and Pampean regions, reaching the Atlantic and Pacific Oceans and neighboring countries, such as Argentina, Brazil and Uruguay, driven by the westerly winds at these latitudes. The presence of volcanic aerosol layers could be identified promptly at the proximities of Calbuco and afterwards by remote sensing using satellites and lidars in the path of the dispersed aerosols. The Cloud-Aerosol Lidar and Pathfinder Satellite Observations (CALIPSO), Moderate Resolution Imaging Spectroradiometer (MODIS) on board of AQUA/TERRA satellites and Ozone Mapping and Profiler Suite (OMPS) on board of Suomi National Polar-orbiting Partnership (Suomi NPP) satellite were the space platforms used to track the injected layers and a multi-channel lidar system from Latin America Lidar Network (LALINET) SPU Lidar station in South America allowed us to get the spatial and temporal distribution of Calbuco ashes after its occurrence. The SPU lidar stations co-located Aerosol Robotic Network (AERONET) sunphotometers to help in the optical characterization. Here, we present the volcanic layer transported over São Paulo area and the detection of aerosol plume between 18 and 20 km. The path traveled by the volcanic aerosol to reach the Metropolitan Area of São Paulo (MASP) was tracked by CALIPSO and the aerosol optical and geometrical properties were retrieved at some points to monitor the plume evolution. Total attenuated backscatter profile at 532 nm obtained by CALIPSO revealed the height range extension of the aerosol plume between 18 and 20 km and are in agreement with SPU lidar range corrected signal at 532 nm. The daily evolution of Aerosol Optical Depth (AOD) at 532 and 355 nm, retrieved from AERONET sunphotometer, showed a substantial increasing on 27 April, the day of the volcanic plume detection at Metropolitan Area of São Paulo (MASP), achieving values of 0 . 33 ± 0 . 16 and 0 . 22 ± 0 . 09 at 355 and 532 nm, respectively. AERONET aerosol size distribution was dominated by fine mode aerosol over coarse mode, especially on 27 and 28 April. The space and time coincident aerosol extinction profiles from SPU lidar station and OMPS LP from the Calbuco eruption conducted on 27 April agreed on the double layer structure. The main objective of this study was the application of the transmittance method, using the Platt formalism, to calculate the optical and physical properties of volcanic plume, i.e., aerosol bottom and top altitude, the aerosol optical depth and lidar ratio. The aerosol plume was detected between 18 and 19.3 km, with AOD value of 0.159 at 532 nm and Ånsgtröm exponent of 0 . 61 ± 0 . 58 . The lidar ratio retrieved was 76 ± 27 sr and 63 ± 21 sr at 532 and 355 nm, respectively. Considering the values of these parameters, the Calbuco volcanic aerosol layers could be classified as sulfates with some ash type