scholarly journals Observed and Projected Changes in Temperature and Precipitation in the Core Crop Region of the Humid Pampa, Argentina

Climate ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 40
Author(s):  
Gabriela V. Müller ◽  
Miguel A. Lovino ◽  
Leandro C. Sgroi
Keyword(s):  
Climate Extremes ◽  
Annual Precipitation ◽  
Climate Conditions ◽  
The Core ◽  
Temperature And Precipitation ◽  
Mean Temperature ◽  
Maximum Temperatures ◽  
Projected Changes ◽  
Precipitation Changes ◽  
Precipitation Events

The core crop region of the Humid Pampa is one of the most productive agricultural lands around the world and depends highly on climate conditions. This study assesses climate variability, climate extremes, and observed and projected climate changes there, using 1911–2019 observations and CMIP5 model simulations. Since 1970, the annual mean temperature has risen by 1 °C and the mean annual minimum and maximum temperatures by 2 and 0.5 °C, respectively. The frequency of warm days and nights increased, and cold days and nights decreased. Heatwaves became longer and more intense, and cold waves decreased with less frost events. Annual precipitation increased by 10% from 1911, mainly in summer, and years with excess precipitation outnumbered those with a deficit. Both intense precipitation events and consecutive dry days grew, suggesting more annual precipitation falling on fewer days. Projections show a warming of 1 °C by 2035, regardless of the scenario. From then on until 2100, mean temperature will increase by 2 and 3–3.5 °C in the RCP4.5 and RCP8.5 scenarios, respectively. Annual precipitation will grow 8 and 16% from current values by 2100 in the RCP4.5 and RCP8.5 scenarios, respectively. No major precipitation changes are projected in the RCP2.6 scenario.

scholarly journals Changes in regional climate extremes as a function of global mean temperature: an interactive plotting framework

2017 ◽  
Author(s):  
Richard Wartenburger ◽  
Martin Hirschi ◽  
Markus G. Donat ◽  
Peter Greve ◽  
Andy J. Pitman ◽  
...  
Keyword(s):  
Water Cycle ◽  
Regional Climate ◽  
Coupled Model ◽  
Climate Extremes ◽  
Global Mean Temperature ◽  
Mean Temperature ◽  
Intercomparison Project ◽  
Projected Changes ◽  
Regional Analyses ◽  
Global Mean

Abstract. This article extends a previous study (Seneviratne et al., 2016) to provide regional analyses of changes in climate extremes as a function of projected changes in global mean temperature. We introduce the DROUGHT-HEAT Regional Climate Atlas, an interactive tool to analyse and display a range of well-established climate extremes and water-cycle indices and their changes as a function of global warming. These projections are based on simulations from the 5th phase of the Coupled Model Intercomparison Project (CMIP5). A selection of example results are presented here, but users can visualize specific indices of interest using the online tool. This implementation enables a direct assessment of regional climate changes associated with global temperature targets, such as the 2 degree and 1.5 degree limits agreed within the 2015 Paris Agreement.

Projected changes in extreme precipitation events over Iran in the 21st century based on CMIP5 models

2020 ◽  
Vol 82 ◽  
pp. 75-95
Author(s):  
M Darand
Keyword(s):  
21St Century ◽  
Extreme Precipitation ◽  
Model Simulation ◽  
Climate Extremes ◽  
Cmip5 Models ◽  
Trend Test ◽  
Extreme Precipitation Events ◽  
Increased Risk ◽  
Projected Changes ◽  
Precipitation Events

Climate extremes have large impacts on human societies and natural ecosystems. Projection of changes in climate extremes is very important for long-term planning. The current study investigated future changes in extreme precipitation events over Iran based on 18 CMIP5 models for the period 2006-2100. National gridded data from the Asfazari database were used to evaluate climate model simulation. Results indicate that models with higher spatial resolution (CCSM4 and MRI-CGCM3) perform better than those with lower resolution in capturing the spatial features of extreme precipitation events. Bias correction was applied to the models and the projected changes were assessed with the nonparametric modified Mann-Kendal trend test and Sen slope estimator at a 95% confidence level. Annual total precipitation (PRPCTOT) and rainy days (RD) were projected to decrease but the intensity and frequency of precipitation extremes were predicted to increase significantly. The projected decreases were larger in northwestern parts than other regions, with PRPCTOT decreasing by 18 to 22 mm decade-1 and RD by 4 to 4.8 d decade-1. Although there were discrepancies in rates between the models, extreme precipitation events over Iran were generally projected to increase. An increase in consecutive dry days (CDD) was predicted for most regions by the end of the 21st century under RCP8.5, with the largest increase of 5 to 6.8 d decade-1 found for northwestern Iran. In eastern areas of Iran, where precipitation occurs extremely rarely, the number of days with daily precipitation exceeding 10 mm (R10) or even 20 mm (R20) were projected to increase significantly. In conclusion, these changes suggest an increased risk of flash floods in Iran from increased extreme precipitation under the RCP8.5 emission scenario.

scholarly journals Large-scale atmospheric circulation biases and changes in global climate model simulations and their importance for climate change in Central Europe

2006 ◽  
Vol 6 (4) ◽  
pp. 863-881 ◽  
Author(s):  
A. P. van Ulden ◽  
G. J. van Oldenborgh
Keyword(s):  
Climate Change ◽  
Central Europe ◽  
Large Scale ◽  
Global Climate Model ◽  
Late Summer ◽  
Geostrophic Flow ◽  
Temperature And Precipitation ◽  
Mean Temperature ◽  
Precipitation Changes ◽  
Circulation Changes

Abstract. The quality of global sea level pressure patterns has been assessed for simulations by 23 coupled climate models. Most models showed high pattern correlations. With respect to the explained spatial variance, many models showed serious large-scale deficiencies, especially at mid-latitudes. Five models performed well at all latitudes and for each month of the year. Three models had a reasonable skill. We selected the five models with the best pressure patterns for a more detailed assessment of their simulations of the climate in Central Europe. We analysed observations and simulations of monthly mean geostrophic flow indices and of monthly mean temperature and precipitation. We used three geostrophic flow indices: the west component and south component of the geostrophic wind at the surface and the geostrophic vorticity. We found that circulation biases were important, and affected precipitation in particular. Apart from these circulation biases, the models showed other biases in temperature and precipitation, which were for some models larger than the circulation induced biases. For the 21st century the five models simulated quite different changes in circulation, precipitation and temperature. Precipitation changes appear to be primarily caused by circulation changes. Since the models show widely different circulation changes, especially in late summer, precipitation changes vary widely between the models as well. Some models simulate severe drying in late summer, while one model simulates significant precipitation increases in late summer. With respect to the mean temperature the circulation changes were important, but not dominant. However, changes in the distribution of monthly mean temperatures, do show large indirect influences of circulation changes. Especially in late summer, two models simulate very strong warming of warm months, which can be attributed to severe summer drying in the simulations by these models. The models differ also significantly in the simulated warming of cold winter months. Finally, the models simulate rather different changes in North Atlantic sea surface temperature, which is likely to impact on changes in temperature and precipitation. These results imply that several important aspects of climate change in Central Europe are highly uncertain. Other aspects of the simulated climate change appear to be more robust. All models simulate significant warming all year round and an increase in precipitation in the winter half-year.

scholarly journals Changes in regional climate extremes as a function of global mean temperature: an interactive plotting framework

2017 ◽  
Vol 10 (9) ◽  
pp. 3609-3634 ◽  
Author(s):  
Richard Wartenburger ◽  
Martin Hirschi ◽  
Markus G. Donat ◽  
Peter Greve ◽  
Andy J. Pitman ◽  
...  
Keyword(s):  
Water Cycle ◽  
Regional Climate ◽  
Coupled Model ◽  
Climate Extremes ◽  
Global Mean Temperature ◽  
Mean Temperature ◽  
Intercomparison Project ◽  
Projected Changes ◽  
Regional Analyses ◽  
Global Mean

Abstract. This article extends a previous study Seneviratne et al. (2016) to provide regional analyses of changes in climate extremes as a function of projected changes in global mean temperature. We introduce the DROUGHT-HEAT Regional Climate Atlas, an interactive tool to analyse and display a range of well-established climate extremes and water-cycle indices and their changes as a function of global warming. These projections are based on simulations from the fifth phase of the Coupled Model Intercomparison Project (CMIP5). A selection of example results are presented here, but users can visualize specific indices of interest using the online tool. This implementation enables a direct assessment of regional climate changes associated with global mean temperature targets, such as the 2 and 1.5° limits agreed within the 2015 Paris Agreement.

A 12 000 year palynological record of temperature and precipitation trends in southwestern British Columbia

1981 ◽  
Vol 59 (5) ◽  
pp. 707-710 ◽  
Author(s):  
Rolf W. Mathewes ◽  
Linda E. Heusser
Keyword(s):  
Transfer Functions ◽  
Late Glacial ◽  
Mean Annual Precipitation ◽  
Before Present ◽  
Pollen Data ◽  
The Core ◽  
Temperature And Precipitation ◽  
Maximum Temperatures ◽  
Reconstructed Precipitation ◽  
July Temperature

Transfer functions for converting pollen frequencies to estimates of mean July temperature and mean annual precipitation were applied to fossil pollen data from a sediment core in Marion Lake. The paleotemperature curve shows low July temperatures near 14 °C at the base of the core at about 12 000 before present (B.P.), rising rapidly between 10 400 B.P. and 10 000 B.P. to maximum values slightly above 16 °C. Maximum temperatures cluster between 10 000 B.P. and approximately 7500 B.P., declining steadily thereafter until 6000 B.P. Little change is apparent from 6000 B.P. to the present. The reconstructed precipitation curve also shows a three-part zonation, with moderately high values between 12 000 and 10 400 B.P. dropping rapidly to minimum Holocene values between 10 000 and 7500 B.P. Precipitation rises to modern levels near the Mazama ash bed. The informal term "early Holocene xerothermic interval" is applied to the pre-Mazama interval of maximum temperatures and minimum precipitation.The late-glacial age at the base of the core is confirmed by a new radiocarbon date of 11 920 ± 245 years B.P. (I-6857) on lodgepole pine needles screened from the basal clays.

scholarly journals Simulating the temperature and precipitation signal in an Alpine ice core

2013 ◽  
Vol 9 (4) ◽  
pp. 2013-2022 ◽  
Author(s):  
S. Brönnimann ◽  
I. Mariani ◽  
M. Schwikowski ◽  
R. Auchmann ◽  
A. Eichler
Keyword(s):  
Climate Models ◽  
Climate Model ◽  
Meteorological Data ◽  
Ice Core ◽  
Ice Cores ◽  
Irregular Sampling ◽  
Temperature And Precipitation ◽  
Mean Temperature ◽  
Ice Core Record ◽  
Precipitation Events

Abstract. Accumulation and δ18O data from Alpine ice cores provide information on past temperature and precipitation. However, their correlation with seasonal or annual mean temperature and precipitation at nearby sites is often low. This is partly due to the irregular sampling of the atmosphere by the ice core (i.e. ice cores almost only record precipitation events and not dry periods) and the possible incongruity between annual layers and calendar years. Using daily meteorological data from a nearby station and reanalyses, we replicate the ice core from the Grenzgletscher (Switzerland, 4200 m a.s.l.) on a sample-by-sample basis by calculating precipitation-weighted temperature (PWT) over short intervals. Over the last 15 yr of the ice core record, accumulation and δ18O variations can be well reproduced on a sub-seasonal scale. This allows a wiggle-matching approach for defining quasi-annual layers, resulting in high correlations between measured quasi-annual δ18O and PWT. Further back in time, the agreement deteriorates. Nevertheless, we find significant correlations over the entire length of the record (1938–1993) of ice core δ18O with PWT, but not with annual mean temperature. This is due to the low correlations between PWT and annual mean temperature, a characteristic which in ERA-Interim reanalysis is also found for many other continental mid-to-high-latitude regions. The fact that meteorologically very different years can lead to similar combinations of PWT and accumulation poses limitations to the use of δ18O from Alpine ice cores for temperature reconstructions. Rather than for reconstructing annual mean temperature, δ18O from Alpine ice cores should be used to reconstruct PWT over quasi-annual periods. This variable is reproducible in reanalysis or climate model data and could thus be assimilated into conventional climate models.

scholarly journals Possible Scenarios of Winter Wheat Yield Reduction of Dryland Qazvin Province, Iran, Based on Prediction of Temperature and Precipitation Till the End of the Century

Climate ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 78 ◽  
Author(s):  
Behnam Mirgol ◽  
Meisam Nazari
Keyword(s):  
Winter Wheat ◽  
Crop Yields ◽  
Wheat Yield ◽  
Annual Precipitation ◽  
Yield Reduction ◽  
Factors Affecting ◽  
Temperature And Precipitation ◽  
Mean Temperature ◽  
Winter Wheat Yield ◽  
Semi Arid

The climate of the Earth is changing. The Earth’s temperature is projected to maintain its upward trend in the next few decades. Temperature and precipitation are two very important factors affecting crop yields, especially in arid and semi-arid regions. There is a need for future climate predictions to protect vulnerable sectors like agriculture in drylands. In this study, the downscaling of two important climatic variables—temperature and precipitation—was done by the CanESM2 and HadCM3 models under five different scenarios for the semi-arid province of Qazvin, located in Iran. The most efficient scenario was selected to predict the dryland winter wheat yield of the province for the three periods: 2010–2039, 2040–2069, and 2070–2099. The results showed that the models are able to satisfactorily predict the daily mean temperature and annual precipitation for the three mentioned periods. Generally, the daily mean temperature and annual precipitation tended to decrease in these periods when compared to the current reference values. However, the scenarios rcp2.6 and B2, respectively, predicted that the precipitation will fall less or even increase in the period 2070–2099. The scenario rcp2.6 seemed to be the most efficient to predict the dryland winter wheat yield of the province for the next few decades. The grain yield is projected to drop considerably over the three periods, especially in the last period, mainly due to the reduction in precipitation in March. This leads us to devise some adaptive strategies to prevent the detrimental impacts of climate change on the dryland winter wheat yield of the province.

Phytogeography and climate analysis of Nothofagus subgenus Brassospora in New Guinea and New Caledonia

2005 ◽  
Vol 53 (4) ◽  
pp. 297 ◽  
Author(s):  
Jennifer Read ◽  
Geoffrey S. Hope ◽  
Robert S. Hill
Keyword(s):  
New Caledonia ◽  
New Guinea ◽  
Niche Differentiation ◽  
Annual Precipitation ◽  
Wet Season ◽  
Temperature And Precipitation ◽  
Mean Temperature ◽  
Extant Species ◽  
Significant Difference ◽  
Climate Analysis

Nothofagus subgenus Brassospora now occurs only in New Guinea and New Caledonia, but is well known from fossil deposits of South America, New Zealand, Antarctica and Australia. It is commonly used for palaeoclimatic interpretation, but the climate characteristics of the extant species have not been described. In this paper we used the climatic estimation software, BIOCLIM, to derive a climate profile of 24 variables for each of the 14 species of Nothofagus native to New Guinea, and lapse rates and isohyet maps to describe the annual mean temperature and rainfall range of the five species native to New Caledonia. The New Guinea species occur at annual mean temperatures ranging from 10.6 to 23.5°C, with annual precipitation of 1762–7733 mm. The first three axes of a principal components analysis explained 85% of the total variation, the first axis comprising temperature variables, the second comprising precipitation range and precipitation of the wet season, and the third axis comprising dry-season precipitation and annual and diurnal temperature range. Some species had distinct combinations of positions along these component axes, indicating clear niche differentiation with respect to climate. The New Caledonian species occur at annual mean temperatures of 14.5–23.5°C, and annual precipitation of c. 1500–3500 mm. Although there was no significant difference in annual mean temperature and precipitation between the New Guinea and New Caledonian species, comparison of median values across species suggests specialisation of most New Caledonian species towards slightly drier conditions than the New Guinea species that occur at similarly high annual mean temperatures. Use of subgenus Brassospora to interpret palaeoclimates should take into account the variation in climate experienced across the range of extant species.

scholarly journals Simulating the temperature and precipitation signal in an Alpine ice core

2012 ◽  
Vol 8 (6) ◽  
pp. 6111-6134 ◽  
Author(s):  
S. Brönnimann ◽  
I. Mariani ◽  
M. Schwikowski ◽  
R. Auchmann ◽  
A. Eichler
Keyword(s):  
Meteorological Data ◽  
Ice Core ◽  
Ice Cores ◽  
Irregular Sampling ◽  
Temperature And Precipitation ◽  
Mean Temperature ◽  
Temperature Reconstructions ◽  
Ice Core Record ◽  
Precipitation Events

Abstract. Accumulation and δ18O data from Alpine ice cores provide information on past temperature and precipitation. However, their correlation with seasonal or annual mean temperature and precipitation at nearby sites is often low. Based on an example we argue that, to some extent, this is due to the irregular sampling of the atmosphere by the ice core (i.e. ice cores only record precipitation events and not dry periods) and the possible incongruity between annual layers and calendar year due to dating uncertainty. Using daily meteorological data from nearby stations and reanalyses we replicate the ice core from the Grenzgletscher (Switzerland, 4200 m a.s.l.) on a sample-by-sample basis. Over the last 15 yr of the ice core record, accumulation and δ18O variations can be well reproduced on a sub-seasonal scale. This allows a wiggle-matching approach for defining quasi-annual layers. For this period, correlations between measured and replicated quasi-annual δ18O values approach 0.8. Further back in time, the quality of the agreement deteriorates rapidly. Nevertheless, we find significant correlations for accumulation and precipitation over the entire length of the record (1938–1993), which is not the case when comparing ice core δ18O with annual mean temperature. A Monte Carlo resampling approach of long meteorological time series is used to further explore the relation, in a replicated ice core, between δ18O and annual mean temperature. Results show that meteorologically very different years can lead to quasi-identical values for δ18O. This poses limitations to the use of δ18O from Alpine ice cores for temperature reconstructions in regions with a variable seasonality in precipitation.

scholarly journals Unpacking future climate extremes and their sectoral implications in western Nepal

2021 ◽  
Vol 168 (1-2) ◽  
Author(s):  
Dipesh Chapagain ◽  
Sanita Dhaubanjar ◽  
Luna Bharati
Keyword(s):  
Climate Models ◽  
Regional Climate ◽  
Extreme Temperature ◽  
Climate Extremes ◽  
Climate Indices ◽  
Climate Projections ◽  
Temperature And Precipitation ◽  
Extreme Precipitation Events ◽  
The Impact ◽  
Precipitation Events

AbstractExisting climate projections and impact assessments in Nepal only consider a limited number of generic climate indices such as means. Few studies have explored climate extremes and their sectoral implications. This study evaluates future scenarios of extreme climate indices from the list of the Expert Team on Sector-specific Climate Indices (ET-SCI) and their sectoral implications in the Karnali Basin in western Nepal. First, future projections of 26 climate indices relevant to six climate-sensitive sectors in Karnali are made for the near (2021–2045), mid (2046–2070), and far (2071–2095) future for low- and high-emission scenarios (RCP4.5 and RCP8.5, respectively) using bias-corrected ensembles of 19 regional climate models from the COordinated Regional Downscaling EXperiment for South Asia (CORDEX-SA). Second, a qualitative analysis based on expert interviews and a literature review on the impact of the projected climate extremes on the climate-sensitive sectors is undertaken. Both the temperature and precipitation patterns are projected to deviate significantly from the historical reference already from the near future with increased occurrences of extreme events. Winter in the highlands is expected to become warmer and dryer. The hot and wet tropical summer in the lowlands will become hotter with longer warm spells and fewer cold days. Low-intensity precipitation events will decline, but the magnitude and frequency of extreme precipitation events will increase. The compounding effects of the increase in extreme temperature and precipitation events will have largely negative implications for the six climate-sensitive sectors considered here.

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