Enhanced Warming in Global Dryland Lakes and Its Drivers

Lake surface water temperature (LSWT) is sensitive to climate change. Previous studies have found that LSWT warming is occurring on a global scale and is expected to continue in the future. Recently, new global LSWT data products have been generated using satellite remote sensing, which provides an inimitable opportunity to study the LSWT response to global warming. Based on the satellite observations, we found that the warming rate of global lakes is uneven, with apparent regional differences. Indeed, comparing the LSWT warming in different climate zones (from arid to humid), the lakes in drylands experienced more significant warming (0.28 °C decade−1) than those in semi-humid and humid regions (0.19 °C decade−1) during previous decades (1995–2016). By further quantifying the impact factors, it showed that the LSWT warming is attributed to air temperature (74.4%), evaporation (4.1%), wind (9.9%), cloudiness (4.3%), net shortwave (3.1%), and net longwave (4.0%) over the lake surface. Air temperature is the main driving force for the warming of most global lakes, so the first estimate quantification of future LSWT trends can be determined from air temperature projections. By the end of the 21st century, the summer air temperature would warm up to 1.0 °C (SSP1-2.6) and 6.3 °C (SSP5-8.5) over lakes, with a more significant warming trend over the dryland lakes. Combined with their higher warming sensitivity, the excess summer LSWT warming in drylands is expected to continue, which is of great significance because of their high relevance in these water-limited regions.

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Seasonally changing contribution of sea ice and snow cover to uncertainty in multi-decadal Eurasian surface air temperature trends based on CESM simulations

Climate Dynamics ◽

10.1007/s00382-021-05746-4 ◽

2021 ◽

Author(s):

Zhaomin Ding ◽

Renguang Wu

Keyword(s):

Sea Ice ◽

Air Temperature ◽

Western Siberia ◽

Russian Far East ◽

Far East ◽

Surface Air Temperature ◽

The Caspian Sea ◽

Sea Ice Concentration ◽

Northern Siberia ◽

The Impact

AbstractThis study investigates the impact of sea ice and snow changes on surface air temperature (SAT) trends on the multidecadal time scale over the mid- and high-latitudes of Eurasia during boreal autumn, winter and spring based on a 30-member ensemble simulations of the Community Earth System Model (CESM). A dynamical adjustment method is used to remove the internal component of circulation-induced SAT trends. The leading mode of dynamically adjusted SAT trends is featured by same-sign anomalies extending from northern Europe to central Siberia and to the Russian Far East, respectively, during boreal spring and autumn, and confined to western Siberia during winter. The internally generated component of sea ice concentration trends over the Barents-Kara Seas contributes to the differences in the thermodynamic component of internal SAT trends across the ensemble over adjacent northern Siberia during all the three seasons. The sea ice effect is largest in autumn and smallest in winter. Eurasian snow changes contribute to the spread in dynamically adjusted SAT trends as well around the periphery of snow covered region by modulating surface heat flux changes. The snow effect is identified over northeast Europe-western Siberia in autumn, north of the Caspian Sea in winter, and over eastern Europe-northern Siberia in spring. The effects of sea ice and snow on the SAT trends are realized mainly by modulating upward shortwave and longwave radiation fluxes.

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Regional differences in surface air temperature changing patterns from 1960 to 2016 of China

Climate Dynamics ◽

10.1007/s00382-021-05774-0 ◽

2021 ◽

Author(s):

Quanzhi Yuan ◽

Shaohong Wu ◽

Dongsheng Zhao ◽

Erfu Dai ◽

Qin Yuan ◽

...

Keyword(s):

Air Temperature ◽

Regional Differences ◽

Surface Air Temperature ◽

Changing Patterns

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Nature-based cooling potential: a multi-type green infrastructure evaluation in Toronto, Ontario, Canada

International Journal of Biometeorology ◽

10.1007/s00484-021-02100-5 ◽

2021 ◽

Author(s):

Vidya Anderson ◽

William A. Gough

Keyword(s):

Urban Agriculture ◽

Air Temperature ◽

Green Infrastructure ◽

Urban Climate ◽

Surface Air Temperature ◽

Green Roofs ◽

Near Surface ◽

Green Walls ◽

The Impact ◽

Agriculture Systems

AbstractThe application of green infrastructure presents an opportunity to mitigate rising temperatures using a multi-faceted ecosystems-based approach. A controlled field study in Toronto, Ontario, Canada, evaluates the impact of nature-based solutions on near surface air temperature regulation focusing on different applications of green infrastructure. A field campaign was undertaken over the course of two summers to measure the impact of green roofs, green walls, urban vegetation and forestry systems, and urban agriculture systems on near surface air temperature. This study demonstrates that multiple types of green infrastructure applications are beneficial in regulating near surface air temperature and are not limited to specific treatments. Widespread usage of green infrastructure could be a viable strategy to cool cities and improve urban climate.

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Seasonal Surface Air Temperature and Precipitation in the FSU Climate Model Coupled to the CLM2

Journal of Climate ◽

10.1175/jcli3470.1 ◽

2005 ◽

Vol 18 (16) ◽

pp. 3217-3228 ◽

Cited By ~ 16

Author(s):

D. W. Shin ◽

S. Cocke ◽

T. E. LaRow ◽

James J. O’Brien

Keyword(s):

Heat Flux ◽

Air Temperature ◽

Climate Model ◽

Initial Conditions ◽

Sensible Heat Flux ◽

Surface Air Temperature ◽

Community Land Model ◽

Temperature And Precipitation ◽

The Impact ◽

Convective Scheme

Abstract The current Florida State University (FSU) climate model is upgraded by coupling the National Center for Atmospheric Research (NCAR) Community Land Model Version 2 (CLM2) as its land component in order to make a better simulation of surface air temperature and precipitation on the seasonal time scale, which is important for crop model application. Climatological and seasonal simulations with the FSU climate model coupled to the CLM2 (hereafter FSUCLM) are compared to those of the control (the FSU model with the original simple land surface treatment). The current version of the FSU model is known to have a cold bias in the temperature field and a wet bias in precipitation. The implementation of FSUCLM has reduced or eliminated this bias due to reduced latent heat flux and increased sensible heat flux. The role of the land model in seasonal simulations is shown to be more important during summertime than wintertime. An additional experiment that assimilates atmospheric forcings produces improved land-model initial conditions, which in turn reduces the biases further. The impact of various deep convective parameterizations is examined as well to further assess model performance. The land scheme plays a more important role than the convective scheme in simulations of surface air temperature. However, each convective scheme shows its own advantage over different geophysical locations in precipitation simulations.

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Investigating late Holocene variations in hydroclimate and the stable isotope composition of precipitation using southern South American peatlands: an hypothesis

Climate of the Past ◽

10.5194/cp-8-1457-2012 ◽

2012 ◽

Vol 8 (5) ◽

pp. 1457-1471 ◽

Cited By ~ 12

Author(s):

T. J. Daley ◽

D. Mauquoy ◽

F. M. Chambers ◽

F. A. Street-Perrott ◽

P. D. M. Hughes ◽

...

Keyword(s):

Stable Isotope ◽

Air Temperature ◽

Regional Differences ◽

Late Holocene ◽

Isotope Composition ◽

Precipitation Amount ◽

Surface Air Temperature ◽

Global Network ◽

Stable Isotope Composition ◽

Δd And Δ18o

Abstract. Ombrotrophic raised peatlands provide an ideal archive for integrating late Holocene records of variations in hydroclimate and the estimated stable isotope composition of precipitation with recent instrumental measurements. Modern measurements of mean monthly surface air temperature, precipitation, and δD and δ18O-values in precipitation from the late twentieth and early twenty-first centuries provide a short but invaluable record with which to investigate modern relationships between these variables, thereby enabling improved interpretation of the peatland palaeodata. Stable isotope data from two stations in the Global Network for Isotopes in Precipitation (GNIP) from southern South America (Punta Arenas, Chile and Ushuaia, Argentina) were analysed for the period 1982 to 2008 and compared with longer-term meteorological data from the same locations (1890 to present and 1931 to present, respectively). δD and δ18O-values in precipitation have exhibited quite different trends in response to local surface air temperature and precipitation amount. At Punta Arenas, there has been a marked increase in the seasonal difference between summer and winter δ18O-values. A decline in the deuterium excess of summer precipitation at this station was associated with a general increase in relative humidity at 1000 mb over the surface of the Southeast Pacific Ocean, believed to be the major vapour source for the local precipitation. At Ushuaia, a fall in δ18O-values was associated with an increase in the mean annual amount of precipitation. Both records are consistent with a southward retraction and increase in zonal wind speed of the austral westerly wind belt. These regional differences, observed in response to a known driver, should be detectable in peatland sites close to the GNIP stations. Currently, insufficient data with suitable temporal resolution are available to test for these regional differences over the last 3000 yr. Existing peatland palaeoclimate data from two sites near Ushuaia, however, provide evidence for changes in the late Holocene that are consistent with the pattern observed in modern observations.

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Temporal and spatial variation characteristics of temperature and its impact on grain production in Northeast China in recent 50 years

10.21203/rs.3.rs-1098462/v1 ◽

2021 ◽

Author(s):

Weiping Yan ◽

Hongxiang Zhao ◽

Lihua Zhang ◽

Chen Xu ◽

Guobo Tan ◽

...

Keyword(s):

Spatial Variation ◽

Northeast China ◽

Regional Differences ◽

Warming Trend ◽

Grain Production ◽

Temporal And Spatial Variation ◽

Average Wind Speed ◽

Variation Characteristics ◽

Temporal And Spatial ◽

The Impact

Abstract Climate warming has a great impact on grain production in northeast China, but there are few studies on the temporal and spatial variation characteristics of annual Tmean (mean temperature), the impact of meteorological factors on Tmean, and the impact of Tmean increase on grain production in northeast China. This study found that annual Tmean decreased from southeast to northwest in Northeast China, and there were regional differences in spatial distribution. The annual Tmean isoline in Northeast China moves obviously from southeast to northwest. The annual warming trend of Tmean was significant from 1971 to 2000, and moderated from 2001 to 2020. In recent 50 years, Tmean had obvious periodic changes. In the mid-late 1980s, annual Tmean had a sudden warming change, and since then it has been rising continuously. Sunshine hours, average wind speed, evaporation and average air pressure had a very significant correlation with Tmean. In conclusion, the climate change in northeast China in the past 50 years has an obvious warming and drying trend, and there are regional differences in the warming and drying. The warming and drying climate has brought challenges to agricultural production and food security in Northeast China. However, the negative effects of grain production reduction caused by warming and drying climate can be avoided to a certain extent if we deal with it properly.

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Recent Surface Air Temperature Change over Mainland China Based on an Urbanization-Bias Adjusted Dataset

Journal of Climate ◽

10.1175/jcli-d-18-0395.1 ◽

2019 ◽

Vol 32 (10) ◽

pp. 2691-2705 ◽

Cited By ~ 4

Author(s):

Kangmin Wen ◽

Guoyu Ren ◽

Jiao Li ◽

Aiying Zhang ◽

Yuyu Ren ◽

...

Keyword(s):

Air Temperature ◽

North China ◽

Linear Trend ◽

Mainland China ◽

Surface Air Temperature ◽

Data Series ◽

Standard Procedures ◽

Corrected Data ◽

Warming Rate ◽

Temperature Time

Abstract A dataset from 763 national Reference Climate and Basic Meteorological Stations (RCBMS) was used to analyze surface air temperature (SAT) change in mainland China. The monthly historical observational records had been adjusted for urbanization bias existing in the data series of size-varied urban stations, after they were corrected for data inhomogeneities mainly caused by relocation and instrumentation. The standard procedures for creating area-averaged temperature time series and for calculating linear trend were used. Analyses were made for annual and seasonal mean temperature. Annual mean SAT in mainland China as a whole rose by 1.24°C for the last 55 years, with a warming rate of 0.23°C decade−1. This was close to the warming of 1.09°C observed in global mean land SAT over the period 1951–2010. Compared to the SAT before correction, after-corrected data showed that the urbanization bias had caused an overestimate of the annual warming rate of more than 19.6% during 1961–2015. The winter, autumn, spring, and summer mean warming rates were 0.28°, 0.23°, 0.23°, and 0.15°C decade−1, respectively. The spatial patterns of the annual and seasonal mean SAT trends also exhibited an obvious difference from those of the previous analyses. The largest contrast was a weak warming area appearing in central parts of mainland China, which included a small part of southwestern North China, the northwestern Yangtze River, and the eastern part of Southwest China. The annual mean warming trends in Northeast and North China obviously decreased compared to the previous analyses, which caused a relatively more significant cooling in Northeast China after 1998 under the background of global warming slowdown.

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On the Choice of Ensemble Mean for Estimating the Forced Signal in the Presence of Internal Variability

Journal of Climate ◽

10.1175/jcli-d-17-0662.1 ◽

2018 ◽

Vol 31 (14) ◽

pp. 5681-5693 ◽

Cited By ~ 14

Author(s):

Leela M. Frankcombe ◽

Matthew H. England ◽

Jules B. Kajtar ◽

Michael E. Mann ◽

Byron A. Steinman

Keyword(s):

Regional Differences ◽

Climate Model ◽

Surface Air Temperature ◽

Internal Variability ◽

Single Model ◽

Sea Level Pressure ◽

Model Simulations ◽

Ensemble Mean ◽

Climate Model Simulations ◽

The Impact

Abstract In this paper we examine various options for the calculation of the forced signal in climate model simulations, and the impact these choices have on the estimates of internal variability. We find that an ensemble mean of runs from a single climate model [a single model ensemble mean (SMEM)] provides a good estimate of the true forced signal even for models with very few ensemble members. In cases where only a single member is available for a given model, however, the SMEM from other models is in general out-performed by the scaled ensemble mean from all available climate model simulations [the multimodel ensemble mean (MMEM)]. The scaled MMEM may therefore be used as an estimate of the forced signal for observations. The MMEM method, however, leads to increasing errors further into the future, as the different rates of warming in the models causes their trajectories to diverge. We therefore apply the SMEM method to those models with a sufficient number of ensemble members to estimate the change in the amplitude of internal variability under a future forcing scenario. In line with previous results, we find that on average the surface air temperature variability decreases at higher latitudes, particularly over the ocean along the sea ice margins, while variability in precipitation increases on average, particularly at high latitudes. Variability in sea level pressure decreases on average in the Southern Hemisphere, while in the Northern Hemisphere there are regional differences.

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Observational Evidence of the Impact of Vegetation Cover on Surface Air Temperature Change in China

Chinese Journal of Geophysics ◽

10.1002/cjg2.1493 ◽

2010 ◽

Vol 53 (2) ◽

pp. 261-269 ◽

Cited By ~ 8

Author(s):

Xu-Chao YANG ◽

Yi-Li ZHANG ◽

Ming-Jun DING ◽

Lin-Shan LIU ◽

Zhao-Feng WANG ◽

...

Keyword(s):

Temperature Change ◽

Air Temperature ◽

Vegetation Cover ◽

Surface Air Temperature ◽

Observational Evidence ◽

The Impact

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Climatic Changes of Thermal Conditions in the Pacific Subarctic at the Modern Stage of Global Warming

Morskoy gidrofizicheskiy zhurnal ◽

10.22449/0233-7584-2021-2-162-178 ◽

2021 ◽

Vol 37 (2) ◽

Author(s):

I. D. Rostov ◽

E. V. Dmitrieva ◽

N. I. Rudykh ◽

◽

...

Keyword(s):

Air Temperature ◽

Climate Changes ◽

Surface Air Temperature ◽

Ocean Surface ◽

Empirical Orthogonal Functions ◽

Orthogonal Functions ◽

The North ◽

Regional Features ◽

The Pacific ◽

Warming Rate

Purpose. The study is aimed at identifying the regional features of the surface air temperature in the coastal zone and over the Pacific Ocean (to the north of 40° N) manifested as a result of global climate changes at the turn of the XX–XXI centuries, and at assessing their trends and possible causal relationships with the processes in the atmosphere and on the ocean surface. Methods and Results. Based on the Global Meteorological Network and NOAA reanalysis data, the regional features of interannual fluctuations of the surface air temperature and their relationship with variations in the fields of pressure, wind and water temperature on the ocean surface, and with climate indices over the past 4 decades were identified. In order to determine the temperature field spatialtemporal structure and to zone the water area according to the features of climate changes, the methods of cluster, correlation analysis and the apparatus of empirical orthogonal functions were used. The results obtained made it possible to characterize the degree of heterogeneity of the studied area response to the ongoing global changes, to identify different domains and to assess quantitatively the warming rate in these water areas. Conclusions. The tendencies of modern warming are manifested in the trends of interannual air temperature variability, on the average, by ~0.20°C/10 years in the subarctic, and indicate significant regional differences (1.5–2 times) in the ongoing changes. In the west of the region, the warming rate is higher than in the east, where the temperature trends are minimal or statistically insignificant. In the warm period of a year, their values are higher than those in the cold period. The alternation phases of the warm and cold periods are consistent with the variation tendencies in the characteristics both of the atmospheric action centers and various climatic parameters. The corresponding correlations are most widely manifested in variations in the empirical orthogonal functions modes of the H500 geopotential field, and the PDO, NP, SOI, PTW, AD and EP/NP indices. Stable anomalies and trends of the ocean surface temperature in the North Atlantic also play an important role in formation of the Та anomalies in the western subarctic.

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