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Protocol 19 - Climate

Adriano Marlissom Leão de Souza (UFRA)  • E-mail:
Protocol researchers:
East Pará - Dr. Leonardo Deane de Abreu Sá (CRA-INPE)
West Pará - Adriano Marlissom Leão de Souza (UFRA)
Amapá - Dr. Alan Cavalcanti da Cunha (IEPA)
Mato Grosso - Prof. MSc. Kelli Aparecida Munhoz (UNEMAT/AF)

A study of the spatial and temporal variability of bioclimatological parameters in regions with research sites belonging to the PPBio biodiversity research program.

Overall objective:

To determine spatial and temporal variability standards within the PPBIO sites, integrating local measures in tandem with information obtained through environmental satellites, and by numeric simulation in terms of the amount of atmospheric flow across the region.

Specific Objectives:

§  To use high resolution satellite images to obtain spatial variability standards in relation to various surface parameters such as spatial roughness and leaf area index (LAI) in regions containing PPBio sites, in addition to the detection of regions of particular scientific interest (such as clearings, for example) in pre-determined areas.

§  To carry out high spatial resolution numerical simulations of the atmospheric flow in regions containing PPBio sites.

§  To study temporal variability of bioclimatological magnitudes, measured at fixed points (towers, masts etc.) in regions containing the PPBio sites, with emphasis on the detection of the scales at which greater variability exists, utilizing the potential offered by advanced mathematical methods (such as research into long temporal series and application of the Wavelet Transform for analysis of variability by scale, for example).

§  To study the vertical variability of meteorological magnitudes, measured at towers set out within the PPBio sites, with emphasis on the detection of conditions of stability within and above the forest canopy, including its diurnal and seasonal variability, in addition to the detection of other temporal scales of interest.

§  To study the horizontal variability of bioclimatological magnitudes, measured at previously chosen points in regions containing PPBio sites, with emphasis on the detection of gradients of variability and their possible seasonal modifications.

§  To promote the synthesis of information on the spatial variability of the spatial roughness, provided by remote detection, for the purposes of analyzing these parameters in relation to statistical methods such as multivariate regression and Pearson correlation; these being the most used methods for linking or mapping the biomass and texture of optical and radar images (LU; BATISTELLA, 2005; PINHEIRO, 2007), incorporating them into the lower boundary conditions of the numerical models for simulating flow in the lower atmosphere in order to provide more accurate information on patterns of spatial variability within the PPBio sites. To validate information based on the fields of bioclimatological magnitudes, by means of in situ measurements within towers and/or on trails, at locations especially chosen for best determining the spatial gradients.

§  To associate micrometeorological variations with the biodiversity and phenology of the terrestrial biota, in addition to studying the influence of soil moisture on soil respiration and the behaviour of micrometeorological magnitudes in the areas above.

§  To make information available on the variability of the meteorological and bioclimatological magnitudes for other PPBio Project groups, in addition to promoting scientific discussions in order to optimize the potential of the aforementioned parameters.

§  To contribute to the training of human resources through incorporation into the program of trainees, scientific undergraduate students and post-graduate students, including researchers visiting the Center for Climate Research.

§  To disclose the scientific results obtained through all available mediums, including scientific articles published in magazines containing editorial content, scientific congresses, seminars etc.

The Climate

Methodologies have been introduced within this proposal that enable us to associate the potential supplied by high resolution spatial information from environmental satellites, such as numerical modeling of the lower atmosphere with high spatial resolution, in order to obtain further relevant information beyond that supplied by micrometeorological and bioclimatological measurements, carried out in situ within the area of each PPBio site.

The theoretical basis for the study of the climate at the PPBio sites is already contained in existing information about the characteristics of atmospheric circulation over South America (in general) and the Amazon (in particular), as well as factors that determine climate variability at different spatial and temporal scales (Books: Geophysiology of Amazônia, ABRACOS, Águas, Edições Especiais do JGR (2002), Climatic Change, Acta Amazônica, Revista Brasileira de Meteorologia (2006), in addition to articles such as Molion (1987); Cohen et al. (1995); Nogués-Peagle and Mo (1997); Machado et al. (1998), Marengo (2005; 2007), Vera et al. (2006), Costa et al. (2007) etc.

It is evident that such studies are very complex because, under certain conditions, large scales impose variability standards on lower scales, but at other times they do not. As an example; consider situations in which large scale phenomenons predominate, associated with anomalies in the surface temperatures of the seas in oceans adjacent to Latin America, such as El Niño (PHILANDER, 1990), Intertropical Convergence Zones (ITCZ) and the South Atlantic convergence zone (SACZ), for example. In such situations, it must be assumed that such phenomena strongly determine the occurrence, or non-occurrence, of rainfall patterns in large areas of the Amazon, which shouldn’t be true however during other periods when these phenomena have less dominant roles. Furthermore, Garstang e Fitzjarrald (1999) and Strong et al. (2005), among other authors, call attention to specific characteristics of the atmospheric boundary layer (ABL) in tropical rainforest areas, as well as the role that atmospheric flow at a synoptic scale has on influencing processes such as the development of the boundary layer, the formation of clouds, rainfall patterns and atmospheric electricity, in which on many occasions there is a large connection between a wide band of scales.

Furthermore, with regard to temporal variability, the existence of already available long temporal-series will allow phenomena to be investigated across a wide range of scales, using methodologies similar to those proposed by Baldocchi et al. (2001) and Katul et al. (2001). With regard to spatial variability, studies must be carried out for both vertical and horizontal variations. With regard to vertical variability, the starting point will be to analyze data from meteorological towers, particularly the temperature and humidity vertical profiles, as well as conducting experimental campaigns in order to carry out radio soundings, these results being of fundamental importance for the initialization and calibration of numerical models. To get an idea of overall relevance, it is worth mentioning that the forest canopy is always the most heated region during the day. This creates a positive virtual potential temperature from the top of the canopy, down, and a negative virtual potential temperature from the top of the canopy, up, i.e. stable conditions predominating below the canopy and unstable conditions predominating above. The opposite should happen at night, principally during dry and cloudless conditions. In such conditions during the night, situations may occur in which the levels closest to the surface can become hotter than the levels above, creating heat induced circulation that mixes the atmospheric flow and tends to reduce the vertical gradients of humidity and temperature, having bioclimatological consequences that are still not completely understood.

In relation to horizontal variability, limited study has already been carried out in the Manaus region in the state of Amazônia (AM), in relation to rainfall. These studies point to significant differences between measurements taken close to or further away from the River Amazonas, associated with the peculiar characteristics of the mesoscale circulation induced by the existence of a large body of water. There are also reports of the occurrence of two maximum days of rainfall in the region immediately next to River Tapajós, an occurrence that does not occur in more remote regions of this river (LU et al., 2005). Particularly, in terms of mesoscale meteorology, the existence of the Baia de Caxiuanã near to the Caxiuanã FLONA (National Forest) possibly facilitates the occurrence of wind bursts (COHEN et al., 2005; Nogueira, 2008), as well as possible maximum levels of convective available potential energy (CAPE) at the end of the afternoon (MONTEIRO DA SILVA, 2008; Nogueira, 2008), appearing to play an important role in the creation of intermittent phenomena during the night, with evident consequences for the variability of microclimatic magnitudes in the forest environment. Lloyd and Marques Filho (1988) have demonstrated that rainfall distribution is log-normal in relation to the small-scale horizontal variability of rainfall below the vegetation canopy, which in principle makes it extremely difficult to establish simple strategies for a robust estimation of the average amount of rainfall below the Amazon Forest canopy (BAKER; GIBSON, 1987).

The establishment of experimental PPBio sites has enhanced the formulation of an initial strategy for obtaining relevant scientific information, while maintaining a cost-benefit relationship, i.e. getting maximum information while expending the minimum amount of resources during the deployment of staff and materials at the experimental site. This suggests, based on available micrometeorological and microclimatological data, that a number of major axes have already been defined in terms of studying variability: on the one hand, through identification of the regions in which the horizontal gradients of the meteorological magnitudes are most relevant (at a scale of a few kilometers); and, on the other hand, through identification of small scale horizontal variability situations (at a scale of hundreds of meters or less), of particular use for bioclimatic studies.

When identifying regions with relevant horizontal gradients at a scale of a few kilometers, the topography and distance from large bodies of water particularly stands out (this being valid for Caxiuanã, or more generally, for regions with different types of vegetation covers, different land usage levels, different levels of moisture and/or soil temperatures, etc.).

As is already well known, the creation of clearings within forests is of enormous ecological importance, in addition to becoming an important factor in the creation of biodiversity (NELSON et al., 1994). Satellite detection and site investigation studies (over a minimum of one year) on recently created clearings will be relevant for the understanding of microclimatic development in such regions (MILLER et al., 2007), as well as being of obvious use for biological studies. Effectively, many live organisms are demonstrably sensitive to microclimate conditions, this surely being one of the factors that affects the spatial distribution of a wide range of living things, such as insects and fungi, for example (AQUINO; ASSIS, 2005)

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