scholarly journals Regional climate changes due to double CO2 simulation by CCM3

MAUSAM ◽  
2021 ◽  
Vol 52 (1) ◽  
pp. 221-228
Author(s):  
P. K. PAL ◽  
P. K. THAPLIYAL ◽  
A. K. DWAVEDI
Keyword(s):  
Climate Changes ◽  
Climate Model ◽  
Regional Climate ◽  
Longwave Radiation ◽  
Model Atmosphere ◽  
Total Rainfall ◽  
Long Term Trends ◽  
Temporal And Spatial ◽  
Equilibrium Experiment

An equilibrium experiment has been conducted with CCM3 climate model in which the amount of CO2 in  the model atmosphere is doubled and the differences in resulting climate has been examined. The results show that there is an overall decrease in outgoing longwave radiation indicating the possible increase in cloudiness. The total rainfall may not change significantly but the temporal and spatial distributions over India are likely to change as observed in past long term trends.

scholarly journals A Long-Term, 1-km Resolution Daily Meteorological Dataset for Modeling and Mapping Permafrost in Canada

Atmosphere ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1363
Author(s):  
Yu Zhang ◽  
Budong Qian ◽  
Gang Hong
Keyword(s):  
Land Surface ◽  
Climate Model ◽  
Regional Climate ◽  
Longwave Radiation ◽  
Historical Period ◽  
Air Temperatures ◽  
Downward Longwave Radiation ◽  
High Emission ◽  
Climate Station

Climate warming is causing permafrost thaw and there is an urgent need to understand the spatial distribution of permafrost and its potential changes with climate. This study developed a long-term (1901–2100), 1-km resolution daily meteorological dataset (Met1km) for modeling and mapping permafrost at high spatial resolutions in Canada. Met1km includes eight climate variables (daily minimum, maximum, and mean air temperatures, precipitation, vapor pressure, wind speed, solar radiation, and downward longwave radiation) and is suitable to drive process-based permafrost and other land-surface models. Met1km was developed based on four coarser gridded meteorological datasets for the historical period. Future values were developed using the output of a new Canadian regional climate model under medium-low and high emission scenarios. These datasets were downscaled to 1-km resolution using the re-baselining method based on the WorldClim2 dataset as spatial templates. We assessed Met1km by comparing it to climate station observations across Canada and a gridded monthly anomaly time-series dataset. The accuracy of Met1km is similar to or better than the four coarser gridded datasets. The errors in long-term averages and average seasonal patterns are small. The error occurs mainly in day-to-day fluctuations, thus the error decreases significantly when averaged over 5 to 10 days. Met1km, as a data generating system, is relatively small in data volume, flexible to use, and easy to update when new or improved source datasets are available. The method can also be used to generate similar datasets for other regions, even for the entire global landmass.

scholarly journals Long-term trends in the frequency of severe cyclones of Bay of Bengal : Observations and simulations

MAUSAM ◽  
2021 ◽  
Vol 58 (1) ◽  
pp. 59-66
Author(s):  
O. P. SINGH
Keyword(s):  
Tropical Cyclones ◽  
Bay Of Bengal ◽  
Climate Model ◽  
Model Simulation ◽  
Global Climate ◽  
Regional Climate ◽  
North Indian Ocean ◽  
Anthropogenic Activity ◽  
Long Term Trends

The east coast of India and the coasts of Bangladesh, Myanmar and Sri Lanka are vulnerable to the incidence of tropical cyclones of the Bay of Bengal. Every year these cyclones inflict heavy loss of life and property in this region. Global climate change resulting from anthropogenic activity is likely to manifest itself in the weather and climate of the Bay of Bengal region also. The long-term trends in the frequency and intensity of tropical cyclones of the Bay of Bengal during intense cyclonic months May, October and November is one such problem which has been addressed in the present paper.Utilizing the existing data of 129 years (1877-2005) pertaining to the tropical cyclone frequency and intensity in the Bay of Bengal during May, October and November, a study was undertaken to investigate the trends in the frequency of Severe Cyclonic Storms (SCS) during past decades. The results of the trend analysis reveal that the SCS frequency over the Bay of Bengal has registered significant increasing trends in past 129 years during the intense cyclonic months. It may be emphasized that these trends are long-term trends for more than hundred years based on statistical analyses which do not necessarily imply that SCS frequency has increased continuously decade after decade. As a matter of fact there has been a slight decrease in SCS frequency after peaking in the pentad 1966-1970, but this does not alter the long-term trend much. The intensification rate during November, which accounts for highest number of intense cyclones in the north Indian Ocean, has registered a steep rise of 26% per hundred years, implying that a tropical depression forming in the Bay of Bengal during November has a high probability to reach to severe cyclone stage. A regional climate model simulation revealed the enhanced cyclogenesis in the Bay of Bengal during May, October and November as a result of increased anthropogenic emissions in the atmosphere

Future Extreme Climates Projection over Huang-Huai-Hai Region of China

2014 ◽  
Vol 955-959 ◽  
pp. 3887-3892 ◽  
Author(s):  
Huang He Gu ◽  
Zhong Bo Yu ◽  
Ji Gan Wang
Keyword(s):  
Climate Changes ◽  
Climate Model ◽  
Regional Climate ◽  
Surface Air Temperature ◽  
Daily Rainfall ◽  
Heavy Rain ◽  
Near Surface ◽  
Temperature And Precipitation ◽  
Huai River ◽  
The Future

This study projects the future extreme climate changes over Huang-Huai-Hai (3H) region in China using a regional climate model (RegCM4). The RegCM4 performs well in “current” climate (1970-1999) simulations by compared with the available surface station data, focusing on near-surface air temperature and precipitation. Future climate changes are evaluated based on experiments driven by European-Hamburg general climate model (ECHAM5) in A1B future scenario (2070-2099). The results show that the annual temperature increase about 3.4 °C-4.2 °C and the annual precipitation increase about 5-15% in most of 3H region at the end of 21st century. The model predicts a generally less frost days, longer growing season, more hot days, no obvious change in heat wave duration index, larger maximum five-day rainfall, more heavy rain days, and larger daily rainfall intensity. The results indicate a higher risk of floods in the future warmer climate. In addition, the consecutive dry days in Huai River Basin will increase, indicating more serve drought and floods conditions in this region.

The influence of global climate changes on Western Siberia climate in the first half of XXI century

2018 ◽  
Author(s):  
А.А. Лагутин ◽  
Н.В. Волков ◽  
Е.Ю. Мордвин
Keyword(s):  
Radiative Forcing ◽  
Climate Changes ◽  
Western Siberia ◽  
Climate Model ◽  
Global Climate ◽  
Regional Climate ◽  
First Century ◽  
Global Climate Changes ◽  
Rcp 8.5

Представлены результаты исследований влияния глобальных климатических изменений системы Земля на климат Западной Сибири. Для установления зон региона, в которых к середине XXI в. прогнозируются изменения, использовались модельные данные региональной климатической модели RegCM4 и принятые в этом классе задач стандартизованные евклидовы расстояния между характеристиками климата для двух состояний климатической системы — современного и будущего. Установлены зоны Западной Сибири, в которых в рамках сценариев RCP 4.5 и RCP 8.5 возможной эволюции глобальной системы к 2050 г. прогнозируются изменения климата. Purpose. An analysis of the influence of a global climate changes on the climate of Western Siberia, determination of zones of the region where changes are expected in the middle of the twenty-first century. Methodology. Results obtained using the model data of the regional climate model RegCM4 and the standardized Euclidean distances between climate characteristics. Findings, originality. Simulations of the climate characteristics for the two states of the climate system — contemporary and future — have been carried out. The zones of Western Siberia region, in which climate change is expected in the framework of RCP 4.5 and RCP 8.5 radiative forcing scenarios by the 2050, have been determined.

scholarly journals High resolution atmospheric reconstruction for Europe 1948–2012: coastDat2

2013 ◽  
Vol 6 (2) ◽  
pp. 779-809 ◽  
Author(s):  
B. Geyer
Keyword(s):  
Climate Model ◽  
Numerical Models ◽  
Regional Climate ◽  
Reanalysis Data ◽  
Data Sets ◽  
Data Set ◽  
Horizontal Grid ◽  
Global Reanalysis ◽  
Marine Climate

Abstract. The coastDat data sets were produced to give a consistent and homogeneous database mainly for assessing weather statistics and long-term changes for Europe, especially in data sparse regions. A sequence of numerical models was employed to reconstruct all aspects of marine climate (such as storms, waves, surges etc.) over many decades. Here, we describe the atmospheric part of coastDat2 (Geyer and Rockel, 2013, doi:10.1594/WDCC/coastDat-2_COSMO-CLM). It consists of a regional climate reconstruction for entire Europe, including Baltic and North Sea and parts of the Atlantic. The simulation was done for 1948 to 2012 with a regional climate model and a horizontal grid size of 0.22° in rotated coordinates. Global reanalysis data were used as forcing and spectral nudging was applied. To meet the demands on the coastDat data set about 70 variables are stored hourly.

Customization of RegCM3 Regional Climate Model for Eastern Africa and a Tropical Indian Ocean Domain

2009 ◽  
Vol 22 (13) ◽  
pp. 3595-3616 ◽  
Author(s):  
Neil Davis ◽  
Jared Bowden ◽  
Fredrick Semazzi ◽  
Lian Xie ◽  
Bariş Önol
Keyword(s):  
Spatial Distribution ◽  
Indian Ocean ◽  
Regional Climate Model ◽  
Climate Model ◽  
Regional Climate ◽  
Eastern Africa ◽  
Massachusetts Institute Of Technology ◽  
Convective Rainfall ◽  
Total Rainfall ◽  
Sensitivity Tests

Abstract Rainfall is a driving factor of climate in the tropics and needs to be properly represented within a climate model. This study customizes the precipitation processes over the tropical regions of eastern Africa and the Indian Ocean using the International Centre for Theoretical Physics (ICTP) Regional Climate Model (RegCM3). The convective schemes of Grell with closures Arakawa–Schubert (Grell–AS)/Fritch–Chappel (Grell–FC) and Massachusetts Institute of Technology–Emanuel (MIT–EMAN) were compared to determine the most realistic spatial distribution of rainfall and partitioning of convective/stratiform rainfall when compared to observations from the Tropical Rainfall Measuring Mission (TRMM). Both Grell–AS and Grell–FC underpredicted convective rainfall rates over land, while over the ocean Grell–FC (Grell–AS) over- (under-) estimates convective rainfall. MIT–EMAN provides the most realistic pardoning and spatial distribution of convective rainfall despite the tendency for overestimating total rainfall. MIT–EMAN was used to further customize the subgrid explicit moisture scheme (SUBEX). Sensitivity tests were performed on the gridbox relative humidity threshold for cloudiness (RHmin) and the autoconversion scale factor (Cacs). An RHmin value of 60% (RHmin-60) reduced the amount of total rainfall over five heterogeneous rainfall regions in eastern Africa, with most of the reduction coming from the convective rainfall. Then, Cacs sensitivity tests improved upon the total rainfall amounts and convective stratiform partitioning compared to RHmin-60. Based upon all sensitivity simulations performed, the combination of the MIT–EMAN convective scheme, RHmin-60, and halving the model default value (0.4) of Cacs provided the most realistic simulation in terms of spatial distribution, convective partition, rainfall totals, and temperature bias when compared to observations.

scholarly journals DOWNSCALING TROPICAL CYCLONES FROM GLOBAL RE-ANALYSIS AND SCENARIOS: STATISTICS OF MULTI-DECADAL VARIABILITY OF TC ACTIVITY IN E ASIA

2011 ◽  
Vol 1 (32) ◽  
pp. 17 ◽  
Author(s):  
Hans Von Storch ◽  
Frauke Feser ◽  
Monika Barcikowska
Keyword(s):  
Regional Climate Model ◽  
Tropical Cyclones ◽  
Climate Model ◽  
Decadal Variability ◽  
Tracking System ◽  
Regional Climate ◽  
Automated Tracking ◽  
Stationary Intensity ◽  
Environmental Prediction

An atmospheric regional climate model was employed for describing weather of E Asia for the last decades as well as for the coming century. Re-analyses provided by Global National Center for Environmental Prediction - National Center for Atmospheric Research (NCEP-NCAR) for the past six decades, as well a scenario generated by the ECHAM5/MPI-OM model were dynamically downscaled to a 50 km grid using a state-of-the-art regional climate model (CCLM). Using an automated tracking system, all tropical cyclones (TCs) are identified in the multi-decadal simulations. The different analysis products of TC-statistics were found to differ strongly, also in recent times when the data base was good, so that in the long-term statistics 1950-2010 inhomogeneities mask real climatic variations. The 1948-2009 time series of the annual numbers of TCs in the NCEP-driven simulation and in the JMA best track data (BT) correlate favourably. The number is almost constant, even if there is a slight tendency in BT to show less storms, whereas CCLM shows somewhat more storms, which became more intense. The ECHAM5/MPI-OM-driven scenario simulation, subject to 1959-2100 observed and projected greenhouse gas concentrations, shows a reduction of the number of storms, which maintains a stationary intensity in terms of maximum sustained winds and minimum pressure. Thus, BT-trends and downscaled trends were found to be inconsistent, but also the downscaled trends 1948-2009 and the trends derived from the A1B-scenario were different.

Climate change effects on forest floor interception in woody Cerrado ecosystem

2021 ◽  
Author(s):  
Livia Rosalem ◽  
Miriam Gerrits-Coenders ◽  
Jamil A. A. Anache ◽  
Julian S. Sone ◽  
Dimaghi Schwamback ◽  
...  
Keyword(s):  
Climate Change ◽  
Forest Floor ◽  
Climate Changes ◽  
Climate Model ◽  
Regional Climate ◽  
Climate Change Scenarios ◽  
Water Fluxes ◽  
Climate Change Effects ◽  
Water Partitioning ◽  
Evaporative Flux

<p>The interception process is an important redistributor of water fluxes, which can considerably affect terrestrial evaporation. Not only the canopy intercepts water, but also from the forest floor significant amounts of water vapor return to the atmosphere. Remaining forests are important areas to evaluate the possible effects of climate change on the water partitioning process. Despite the hydrologic and ecosystem services offered by Cerrado forests, the interception process, as well as climate change threats on the evaporative flux of such forests, are still unknown. This study attempts to anticipate the possible impacts on the forest floor interception process in Cerrado stricto sensu considering future scenarios of climate change. To accomplish this, we used data of field monitoring from June 2017 to February 2020 in an undisturbed Cerrado s.s. forest in São Paulo State, Brazil. We calibrated and validated an improved version of the Rutter interception model (Rutter et al., 1971), which includes interception from the forest floor. Projected climate change scenarios were obtained from the National Institute for Space Research (INPE, Brazil) from 2006 to 2099 with 5km spatial resolution generated by Eta-HadGEM2-ES regional climate model under representative concentration pathway (RCP) 4.5. The results indicate increased rainfall and decreased potential evaporation in the decade 2041-2060. By the Rutter model, the total interception increased for this period (2041-2060) associated with decreased forest floor evaporation. During the first (2006-2020) and the last (2081-2099) decades, the predictions suggest an increase of 2.4% on the average annual percentage of forest floor evaporation, also an increase of minimum annual interception percentages (from 17.1% to 18.7%). Thus, our results demonstrate the relevance of forest floor to the interception process and suggest that it can be even more relevant in the future due to the climate changes.</p>

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