Koppen Climate Zones Research Articles

Ranking of CMIP6 based High-resolution Global Climate Models for India using TOPSIS

ABSTRACT Changing temperature and precipitation are the prominent candle bearers of climate change. Global Climate Models (GCM) simulate and predict historical, present, and future climate scenarios. This study focused on selecting the best performing GCM under High-resolution Model Intercomparison Project (HighResMIP) suitable for the Indian subcontinent for predicting daily maximum (Tasmax) and minimum (Tasmin) temperature. Entropy-TOPSIS Multicriteria Decision-Making (MCDM) approach was employed for the relative ranking of GCM models. This study compared 64 years (1951–2014) historical data of 11 high-resolution GCMs under three different nominal resolutions viz., 25 km, 50 km, and 100 km. India Meteorological Department (IMD) gridded data was used as observed data for the performance measure. The data were evaluated using three factors, i.e. Intra- and inter-annual variation of temperature, tempo-spatial extreme events study, and using selected performance indicators. The predictive ability of the GCM models spatially in different Koppen climate zones of India is also reported in this study. This study highlighted Hadgem3-Gc31 and ECMWF-IFS models for Tasmax; NICAM16-8S and MPI-ESM1-2 models for Tasmin are suitable for simulating Indian temperature. The outcome of this study will be helpful to the climate researchers and decision-makers to choose the best suitable CMIP6 GCM model at a regional level.

Evaluating the Applicability of the PUSH Framework to Quasi-Global Infrared Precipitation Retrievals at 0.5°/Daily Spatial/Temporal Resolution

Error estimates associated with satellite precipitation retrievals are crucial to allow inferences about the reliability of such products in their operational applications. However, evaluating satellite precipitation error characteristics is challenging because of the inherent temporal and spatial variability of precipitation, measurement errors, and sampling uncertainties, especially at fine temporal and spatial resolutions. The aim of this study is to estimate errors associated with satellite-based infra-red (IR) precipitation retrievals quasi-globally (60°N − 60°S) over land. The error model adopted for this study is the Probability Uncertainty in Satellite Hydrology (PUSH) framework, which is calibrated and validated against the satellite-based Level-3 Dual frequency precipitation radar product at daily resolution (3DPRD) for different Koppen climate zones. PUSH is shown to efficiently estimate errors in the IR retrievals, although its performance depends on the regional climatology. Specifically, the continental climate zone shows better agreement between observed and estimated errors as compared to other regions, which can be attributed to the general spatial homogeneity of precipitation across this zone and better correlation between IR and 3DPRD estimates.

Quantifying Seasonal Variation in Insecticide-Treated Net Use among Those with Access.

.Seasonal variation in the proportion of the population using an insecticide-treated net (ITN) is well documented and is widely believed to be dependent on mosquito abundance and heat, driven by rainfall and temperature. However, seasonal variation in ITN use has not been quantified controlling for ITN access. Demographic and Health Survey and Malaria Indicator Survey datasets, their georeferenced data, and public rainfall and climate layers were pooled for 21 countries. Nine rainfall typologies were developed from rainfall patterns in Köppen climate zones. For each typology, the odds of ITN use among individuals with access to an ITN within their households (“ITN use given access”) were estimated for each month of the year, controlling for region, wealth quintile, residence, year, temperature, and malaria parasitemia level. Seasonality of ITN use given access was observed over all nine rainfall typologies and was most pronounced in arid climates and less pronounced where rainfall was relatively constant throughout the year. Peak ITN use occurred 1–3 months after peak rainfall and corresponded with peak malaria incidence and average malaria transmission season. The observed lags between peak rainfall and peak ITN use given access suggest that net use is triggered by mosquito density. In equatorial areas, ITN use is likely to be high year-round, given the presence of mosquitoes and an associated year-round perceived malaria risk. These results can be used to inform behavior change interventions to improve ITN use in specific times of the year and to inform geospatial models of the impact of ITNs on transmission.

A global survey of adverse energetic effects of increased wall insulation in office buildings: degree day and climate zone indicators

The energy efficiency of a building depends to a large measure on the characteristics of its envelope insulation. In the special case of internal gain dominated buildings, excessive building insulation may prevent the heat loss through the walls (anti-insulation effect), and thus generate the need for energy-intensive active systems to remove this thermal load. Detailed energetic simulations of a typical office building in Malaga (Spain), Dubai (UAE), and El Dorado (USA) show this anti-insulation effect and its dependency on climatic, constructive, and use factors. Results indicate that buildings in a predominantly cooling environment but within a certain range of heating degree days (HDD) will display this behavior: with very few to no HDD, the building’s energy consumption becomes insensitive to insulation increase (Dubai case); with a low number of HDDs the building becomes sensitive to anti-insulation (Malaga), and once a threshold is passed (El Dorado), the building’s energy consumption decreases with increased insulation. In order to further explore these limitations, simulations in 132 global locations of the building response to a step change in insulation are carried out. Results indicate that buildings in the Koppen climate zones Csa and Csb (Mediterranean climate), in locations with less than 2000 HDD and between 2000 and 5000 cooling degree days (CDD) are most susceptible to this anti-insulation behavior; however, quantitatively, the efficiency loss in these areas due to the insulation increase does not exceed 1 % of the overall energy consumption for the particular building studied and thus remains of limited importance.

Legumes are different: Leaf nitrogen, photosynthesis, and water use efficiency.

Using robust, pairwise comparisons and a global dataset, we show that nitrogen concentration per unit leaf mass for nitrogen-fixing plants (N2FP; mainly legumes plus some actinorhizal species) in nonagricultural ecosystems is universally greater (43-100%) than that for other plants (OP). This difference is maintained across Koppen climate zones and growth forms and strongest in the wet tropics and within deciduous angiosperms. N2FP mostly show a similar advantage over OP in nitrogen per leaf area (Narea), even in arid climates, despite diazotrophy being sensitive to drought. We also show that, for most N2FP, carbon fixation by photosynthesis (Asat) and stomatal conductance (gs) are not related to Narea-in distinct challenge to current theories that place the leaf nitrogen-Asat relationship at the center of explanations of plant fitness and competitive ability. Among N2FP, only forbs displayed an Narea-gs relationship similar to that for OP, whereas intrinsic water use efficiency (WUEi; Asat/gs) was positively related to Narea for woody N2FP. Enhanced foliar nitrogen (relative to OP) contributes strongly to other evolutionarily advantageous attributes of legumes, such as seed nitrogen and herbivore defense. These alternate explanations of clear differences in leaf N between N2FP and OP have significant implications (e.g., for global models of carbon fluxes based on relationships between leaf N and Asat). Combined, greater WUE and leaf nitrogen-in a variety of forms-enhance fitness and survival of genomes of N2FP, particularly in arid and semiarid climates.

Towards Urban Resource Flow Estimates in Data Scarce Environments: The Case of African Cities

Data sourcing challenges in African nations have led many African urban infrastructure developments to be implemented with minimal scientific backing to support their success. In some cases this may directly impact a city’s ability to reach service delivery, economic growth and human development goals, let alone the city’s ability to protect ecosystem services upon which it relies. As an attempt to fill this gap, this paper describes an exploratory process used to determine city-level demographic, economic and resource flow data for African nations. The approach makes use of scaling and clustering techniques to form acceptable and utilizable representations of selected African cities. Variables that may serve as the strongest predictors for resource consumption intensity in African nations and cities were explored, in particular, the aspects of the Koppen Climate Zones, estimates of average urban income and GDP, and the influence of urban primacy. It is expected that the approach examined will provide a step towards estimating and understanding African cities and their resource profiles.

Not for all seasons: why timing is critical in the design of visitor impact monitoring programs for aquatic sites within protected areas

Environmental monitoring is an essential feature of environmental assessment and natural resource management. Whilst the focus of monitoring programs is often on the response of chosen variables to a disturbance of particular concern, it is also important to consider the variability of disturbance pressures in relation to the variability of the ecosystem state. In this paper, we discuss the need to relate environmental variability to disturbance variability in small-scale monitoring programs designed to assess the impact of short-term pulses of visitors on the condition of aquatic ecosystems in protected areas. We use data from protected areas from six Koppen climate zones in Australia to highlight the fact that peaks in visitation do not always coincide with existing monitoring protocols or with optimal times for monitoring on the basis of environmental variability, particularly in relation to rainfall and temperature and, hence, likely biological activity. We highlight how recognising the interaction between disturbance variability and environmental variability will greatly enhance the power of monitoring programs and substantially improve our capacity to detect responses to temporally pulsed disturbances. Analyses of this type, undertaken before the establishment of monitoring programs, will yield higher quality information and a better return on monitoring investment for natural resource managers.

Do Climatic or Institutional Factors Drive Seasonal Patterns of Tourism Visitation to Protected Areas across Diverse Climate Zones in Eastern Australia?

Seasonality in tourism is a regular and predictable cycle of visitation across a year. Although seasonality in visitation is extremely common and is known, in principle, often to be driven by temporal changes in a range of natural and institutional factors, the relative importance of different individual pressures has yet to be quantified for any large-scale geographical areas. To assess the relative importance of natural versus institutional factors in driving tourism seasonality, data on visitation patterns were collated from 23 protected areas across six Koppen climate zones in eastern Australia. Analyses sought to determine the degree to which climatic variables (such as mean monthly rainfall and minimum and maximum temperatures) explained visitation patterns, and to understand how these relationships could assist in the prediction of tourism futures. Climate was the principal force driving seasonal patterns of visitation in equatorial, tropical, desert, grassland and temperate zones, whereas visitation to alpine/sub-alpine areas was driven by a complex array of natural and institutional factors. Tourism seasonality was driven mostly by institutional factors only in the sub-tropical climate zone. These analyses suggest that seasonal characteristics of current visitation could be used to predict the degree to which changes in climate and/or institutional arrangements, such as school holiday periods, might influence tourism opportunities in protected areas in eastern Australia.

Global streamflows – Part 3: Country and climate zone characteristics

Summary This is the final paper in a series of three dealing with global hydrology based on a world-wide historical data set of monthly and annual streamflow records. In this paper hypothetical reservoir capacity estimates and reservoir-yield performance characteristics are compared between countries and between climate zones. The comparison for each characteristic is based mainly on its median value. For the comparison based on countries, the median value for 17 countries was based on at least 10 rivers, and for a further 19 countries on at least three rivers within the country. For the 30 Koppen climate zones, 13 zones had at least 10 rivers and a further seven zones were represented by at least three rivers. Some conclusions include: rivers in the Sahel region of Africa exhibit larger inter-decadal variances compared with those for other global rivers; the observation that western Canadian rivers display longer run lengths than expected from an AR(1) model may be due to the influence of the Pacific Decadal Oscillation; between countries, storage resilience is strongly positively related to reliability, and dimensionless vulnerability is strongly negatively related to reliability; and, finally, rivers in countries that exhibit low resilience tend to show high dimensionless vulnerability. It was also observed for several rivers in Finland and Sudan, that large natural lakes, not unexpectedly, increase streamflow auto-correlation and thereby reduce a reservoir’s ability to recover quickly following a major deficit.

Global analysis of runs of annual precipitation and runoff equal to or below the median: run length

AbstractThe investigation of fluctuations of wet and dry years has a long history in the climatology and hydrology literature. In this, the first of two papers investigating runs of consecutive dry years, the lengths (persistence) of dry runs are investigated. In the second paper the magnitude/intensity and severity (length × magnitude) of dry runs will be investigated. Consecutive dry years are associated with drought, which is a significant physical and economic phenomenon that imposes great stress on ecosystems and societies. Run lengths of consecutive years equal to or below the median were analysed for 3863 precipitation and 1236 runoff stations from around the world. Run lengths were found to be similar across all continents and Köppen climate zones, expect for tropical and arid North Africa (Sahel), which showed a distinct bias toward longer run lengths than any other region of the world. Generally, the run length observed in annual runoff was found to be similar to that observed in annual precipitation for the same location. Both annual precipitation and runoff data were found to be well described by the lag‐one autoregressive (AR(1)) model or by white noise. The influence of the El Niño–southern oscillation on run lengths was not observed to be significant. The presence of decadal and multi‐decadal oscillations was weakly observed in the results of the precipitation runs analysis. The faintness of the decadal and multi‐decadal oscillation signal may be due to the sample sizes not being long enough and/or the runs analysis not being sensitive enough to detect their presence. Copyright © 2004 Royal Meteorological Society

Köppen Climate Types in Observed and Simulated Climates

The Koppen climate classification was applied to the observed gridded climatological sets and the outputs of four general circulation models (GCMs) over the continents of the Earth. All data had been acquired via the Data Distribution Centre established by the Intergovernmental Panel on Climate Change. The ability of the GCMs to simulate the Koppen climate zones identified in the real data was explored and possible future (global warming) changes in the climate types' distribution for each GCM were assessed. Differences in the area distributions derived from the GCMs' recent climate simulations give evidence about uncertainties generally involved in climate models. As to the global warming simulations, all GCM projections of warming climate (horizon 2050) show that the zones representing tropical rain climates and dry climates become larger, and the zones identified with boreal forest and snow climates together with the polar climates are smaller.