Changes in Mean and Extreme Temperature and Precipitation over the Arid Region of Northwestern China:Observation and Projection

This paper reports a comprehensive study on the observed and projected spatiotemporal changes in mean and extreme climate over the arid region of northwestern China, based on gridded observation data and CMIP5 simulations under the RCP4.5 and RCP8.5 scenarios. The observational results reveal an increase in annual mean temperature since 1961, largely attributable to the increase in minimum temperature. The annual mean precipitation also exhibits a significant increasing tendency. The precipitation amount in the most recent decade was greater than in any preceding decade since 1961. Seasonally,the greatest increase in temperature and precipitation appears in winter and in summer, respectively. Widespread significant changes in temperature-related extremes are consistent with warming, with decreases in cold extremes and increases in warm extremes. The warming of the coldest night is greater than that of the warmest day, and changes in cold and warm nights are more evident than for cold and warm days. Extreme precipitation and wet days exhibit an increasing trend, and the maximum number of consecutive dry days shows a tendency toward shorter duration. Multi-model ensemble mean projections indicate an overall continual increase in temperature and precipitation during the 21 st century. Decreases in cold extremes, increases in warm extremes, intensification of extreme precipitation, increases in wet days, and decreases in consecutive dry days, are expected under both emissions scenarios, with larger changes corresponding to stronger radiative forcing.     

The Changing Incidence of Extremes in Worldwide and Central England Temperatures to the End of the Twentieth Century

Annual and seasonal gridded ocean surface temperature anomalies show an increase in warm extremes and a decrease in cold extremes since the late 19th century attributable entirely to the overall warming trend. Over land, however, a reduction in the total incidence of extremes may reflect improved instrumental exposures. Our estimates of extremes are made by deriving percentiles from fits of anomalies on 5° latitude ×5° longitude resolution to modified 2-parameter gamma distributions. A non-parametric method is used to check the validity of the results. Fields of percentiles created using this technique can be used to map the distribution of unusual temperature anomalies across the globe on any time scale from a month to about a decade, from 1870 onwards. We apply a similar technique to assess changes in the incidence of extreme daily Central England temperature anomalies. The incidence of these extremes, relative to individual monthly average temperatures, has declined.     

Trends in extreme temperature indices in Huang-Huai-Hai River Basin of China during 1961–2014

Spatial and temporal characteristics of temperature extremes have been investigated in Huang-Huai-Hai (HHH) region based on the daily series of temperature observations from 162 meteorological stations. A total of 11 indices were used to assess the changes of temperature pattern. Linear trend analyses revealed that the daily maximum temperature (TXx) increased at α = 0.05 level with a magnitude of 0.15 °C per decade on the regional scale during the period of 1961–2014. More pronounced warming trend of the daily minimum temperature (TNn) was detected at a rate of 0.49 °C per decade (α = 0.01 level). Consequently, a decreasing trend of the temperature range of TXx and TNn (extreme temperature range) was observed. The frequency of hot days (TXf90) and annual average of warm events (warm spell duration indicator, WSDI) showed significant increasing trends, while that of cold nights (TNf10) and cold events (cold spell duration indicator, CSDI) showed opposite behaviors. Both warm winter (W-W) and hot summer (H-S) series displayed significant increasing trends at α = 0.01 confidence level. The cold winter (C-W) series showed a decreasing trend at α = 0.01 confidence level, while the cool summer (C-S) series showed a nonsignificant decreasing trend that is not passing the 90% confidence level (α = 0.1). Abrupt increments of warm­related extremes (TXx, TXf90, WSDI) have been detected since 1990s, and a steadily decreasing trend of cold related extremes (TNf10, CSDI) was found since 1970s. Ten hot summers out of 11 and nine warm winters out of 10 occurred after 1990s. Altitude has a large impact on spatial pattern of extreme temperature indices, and the urban heat island effect also has an impact on amplitude of variation in extreme temperature. Trend magnitudes are significantly larger at sites with high altitudes for warm­related indices (TXx, TXf90, WSDI), while those involving cold-related indices (TNn, TNf10) are remarkably larger for stations with low altitudes.     

对喜马拉雅山脉中段6个台站的气候变化分析

利用喜马拉雅山脉中段南、北两侧6个气象站1971-2007年逐月气温、降水资料,分析了该地区气候变化趋势、异常及突变特征。结果表明：喜马拉雅山脉中段南、北两侧年、季平均气温均呈明显上升趋势,冬半年升温幅度大于夏半年。年及夏半年平均气温均为随年代升高趋势,而冬半年气温在20世纪80年代较70年代略偏低,90年代后又逐渐升高。21世纪前7 a升温最为显著,较20世纪70年代升高0.6～1.1℃。1997年该地区南侧年平均气温发生突变,突变后增温趋势更加明显。20世纪90年代末以来,异常偏暖年份出现的几率明显增加,且南侧多于北侧。喜马拉雅山脉中段北侧年及冬夏半年降水均呈增多趋势。南侧年和夏半年降水呈减少趋势,冬半年为增多趋势。降水异常出现在20世纪80、90年代,21世纪后降水出现异常的概率明显减少。近40 a,北侧气候具有暖湿化趋势;南侧冬半年与之类似,但夏半年及全年呈暖干化趋势。     

A diagnosis of twentieth century temperature records at West Lafayette,Indiana

A diagnostic study of 80 yrs(1901–80) of surface temperatures collected at West Lafayette, Indiana, has been found to be in tune with the global trend and that for the eastern two-thirds of the United States, namely, cold at the turn of the century, warming up to about 1940, and then cooling to present. The study was divided into two cold periods (1901–18, 1947–80) and a warm period (1919–46), based on the distribution of annual mean temperature. Decadal mean annual temperatures ranged from 10 °C in period I to 12.2 °C in period II, to 9.4 °C during the present cold period. Themean annual temperature for the 80 yr ranged from the coldest of 8.7 °C in 1979 to the warmest of 13.6 °C in 1939. Thedaily mean temperature for the entire 80-yr ranged from -4.7 °C on 31 January to 25.1 °C on 27 July. Thecoldest daily mean was -26.7 °C on 17 January, 1977, and thewarmest daily mean was 35 °C on 14 July, 1936. The range of values for thedaily mean maximum temperatures was -.2 °C on 31 January to 31.4 °C on 27 July. Corresponding values for thedaily mean minimum are -9.2 °C on 31 January and 18.7 °C on 27 July. The all-time extreme temperatures are -30.6 °C on 26 February, 1963 and 43.9 °C on 14 July, 1936. Climatic variability has been considered by computing the standard deviations of a) the daily mean maximum and minimum temperature per year, and b) the daily mean maximum and minimum temperatures for each day of the year for the 80-yr period. These results have shown that there is more variability in the daily mean maximum per year than in the daily mean minimum, for each year of the 80-yr period. Also the variability for both extremes has been greater in each of the two cold periods than in the warm period. Particularly noticeable has been theincrease in the variability of the daily mean minima per year during the current cooling trend. Further, it has been determined that the variability in the daily mean maxima and minima for each day of the year (based on the entire 80 yrs is a) two times greater in the winter than in the summer for both extremes, and b) about the same for each in the summer, greater for daily maximum in the spring and fall, but greater for the daily minimum during the winter. The latter result is undoubtedly related to the effect of snow cover on daily minimum temperatures. An examination of daily record maximum and minimum temperatures has been made to help establish climatic trends this century. For the warm period, 175 record maxima and 68 record minima were set, compared to 213 record minima and 105 record maxima during the recent cold period. For West Lafayette, the present climatic trend is definitely one of extreme record-breaking cold. Evidence has also been presented to show the substantial increases in snowfall amounts in the lee regions of the Great Lakes during the present cold period, due to the lake-induced snow squalls associated with cold air mass intrusions. The possible impact of the cooling trend on agricultural activities has also been noted, due to a reduced growing season.     

Lapwings in Newfoundland

Abstract

Weather observations made at Eureka, on Ellesmere Island in the Canadian High Arctic, have been archived since 1953. The time series, averages, and seasonal cycles of surface temperature, pressure, dew point, relative humidity, cloud cover, wind speed, and direction are presented for the period from 1954 to 2007. Also shown are the time series and averages for the 500 mb temperature, 900 to 500 mb thickness, 500 mb wind speed, and various boundary‐layer stability parameters. Some of the main trends found are 1) an annual average surface warming of 3.2°C since 1972, with summer exhibiting the least warming, 2) a reduction in the frequency of strong anticyclonic events in the winter, 3) a reduction in surface wind speeds except in the summer, 4) a 1.0°C warming in the 500 mb temperature since 1961, with the greatest warming occurring in the spring and summer, and 5) a 10% increase in precipitable water all year round since 1961 but dominated by the spring, summer, and autumn seasons. The importance of open water in the Arctic Ocean for summer temperatures and humidity, of the North Atlantic Oscillation for winter interannual pressure variability, and of precipitable water for winter temperatures are highlighted in this climatology.     

Influence of circulation types on temperature extremes in Europe

The aim of this study is to determine the influence of atmospheric circulation on the recently observed changes in the number of warm days and cold days in Europe. The temperature series for stations in the European Climate Assessment and Data set project and the Grosswetterlagen (GWL) were used here. The temperature series were first adjusted for global warming before determining the indices for cold and warm extremes. The 29 GWLs were grouped in ten circulation types. Then, the number of days a certain circulation type occurred was determined for each winter (December, January and February) and summer (June, July and August). The relation between the circulation type frequencies and the temperature indices was modelled with a multi-regression fit over the period 1947–1974 and tested for the period 1974–2000. The difference between the observed indices and the calculated indices in the second period (using the fit coefficients for the first period) shows a warming effect for both winter and summer and for at least the warm day index, which is unaccounted for by the global warming trend. A simple snow model shows that variations in the European snow cover extent are likely influencing the cold and warm day indices in winter: there is a correlation between the decreasing trend of the snow cover extent in Europe and the increasing (decreasing) trend of the number of warm (cold) days for stations throughout Europe.     

Trends in Temperature Extremes in Association with Weather-Intraseasonal Fluctuations in Eastern China

Trends in the frequencies of four temperature extremes (the occurrence of warm days, cold days, warm nights and cold nights) with respect to a modulated annual cycle (MAC), and those associated exclusively with weather-intraseasonal fluctuations (WIF) in eastern China were investigated based on an updated homogenized daily maximum and minimum temperature dataset for 1960–2008. The Ensemble Empirical Mode Decomposition (EEMD) method was used to isolate the WIF, MAC, and longer-term components from the temperature series. The annual, winter and summer occurrences of warm (cold) nights were found to have increased (decreased) significantly almost everywhere, while those of warm (cold) days have increased (decreased) in northern China (north of 40°N). However, the four temperature extremes associated exclusively with WIF for winter have decreased almost everywhere, while those for summer have decreased in the north but increased in the south. These characteristics agree with changes in the amplitude of WIF. In particular, winter WIF of maximum temperature tended to weaken almost everywhere, especially in eastern coastal areas (by 10%–20%); summer WIF tended to intensify in southern China by 10%–20%. It is notable that in northern China, the occurrence of warm days has increased, even where that associated with WIF has decreased significantly. This suggests that the recent increasing frequency of warm extremes is due to a considerable rise in the mean temperature level, which surpasses the effect of the weakening weather fluctuations in northern China.     

1961—2020年辽宁省暖冬现象气候特征分析

利用1961—2020年辽宁省56个气象站冬季逐日气温数据,根据国家标准《暖冬等级》,以1990—2020年为气候值作为参考,综合采用气候倾向率、IDW、滑动t检验突变分析以及小波分析等方法,分析辽宁省近60 a冬季平均气温的时空变化趋势,单站暖冬及区域暖冬事件的气候变化特征。结果表明：近60 a来辽宁省冬季平均气温以0.3℃/10 a的速率升高,辽宁中部和东部地区变暖趋势最为显著;20世纪90年代前的30 a属于偏冷时段,但增温效应强于后30 a,冬季平均气温在1987年前后出现了明显的由冷转暖的突变,1971年出现了相对较弱的冷暖转变;1988年后逐年单站暖冬事件的发生整体比1961—1987年出现单站暖冬事件明显增多。发生频次较高的地区分布在辽宁中部和东南部地区,为16—20次;近60 a来共有16次区域暖冬事件,21世纪后的20 a内共出现9次区域暖冬事件,占总数的60%;区域暖冬事件以准22 a和2—3 a为振荡周期。     

近40年我国极端温度变化趋势和季节特征

利用1961—2000年我国194个测站逐日最高温度和最低温度器测资料,结合具有实际意义的季节极端温度指数,分析了我国近40年极端温度事件的年变化趋势和季节特征。对年极端气候指数的研究表明:绝对阈值定义的冷暖指数由于无法考虑南北气候差异,其结果不理想。百分比阈值所得的冷暖指数中,冷日指数和暖日指数具有不对称性,冷夜指数和暖夜指数具有较强的对称性。对季节极端温度指数研究表明:冬季极端冷指数变化趋势最为明显,夏季极端暖指数的变化趋势次之,春、秋两季极端冷指数的变化趋势不明显;年和季节尺度的极端冷暖指数均反映出增暖趋势。     

近60a来洞庭湖区气温的变化特征

以洞庭湖区24个气象站1952-2010年的平均气温资料为基础,利用气候倾向率、Mann-Kendall突变检验法和小波分析等方法,分析了洞庭湖区的气温变化特征.结果表明:洞庭湖区年平均、冬季、春季和秋季气温均呈显著上升趋势,增温速率尤以冬季和春季为甚.除夏季外,年平均和其他各季气温在1990s,先后发生增温性突变.高温日数呈上升趋势,但显著性不明显,低温日数下降趋势非常显著.除夏季外,年平均和各季异常冷年,基本出现在1950s至1970s,异常暖年,均出现在1998年以后.除夏季外,各季气温均存在准9a周期.     

哈尔滨气温的长期变化及基本态特征

利用1881—2009年的气温观测资料,研究了哈尔滨年及四季平均气温的气候基本态和气候变率特征。结果表明,20世纪80年代以来哈尔滨夏季气温变化的异常程度显著增加。在冬季,近期哈尔滨气温处于暖背景及小变率的时段,反映了哈尔滨很长时间内大多数年份还将维持暖冬天气。近49年哈尔滨平均气温、平均最高(低)气温和平均日较差的时间变化特征显示,哈尔滨的年及四季平均气温都呈上升趋势,冬季增暖幅度最大;最高(低)气温变化趋势与平均气温一致,但无论年及四季,平均最高气温的变化速率都小于平均气温,平均最低气温的变化速率都大于平均气温。     

Changes in temperature and precipitation extremes in the CMIP5 ensemble

Twenty-year temperature and precipitation extremes and their projected future changes are evaluated in an ensemble of climate models participating in the Coupled Model Intercomparison Project Phase 5 (CMIP5), updating a similar study based on the CMIP3 ensemble. The projected changes are documented for three radiative forcing scenarios. The performance of the CMIP5 models in simulating 20-year temperature and precipitation extremes is comparable to that of the CMIP3 ensemble. The models simulate late 20th century warm extremes reasonably well, compared to estimates from reanalyses. The model discrepancies in simulating cold extremes are generally larger than those for warm extremes. Simulated late 20th century precipitation extremes are plausible in the extratropics but uncertainty in extreme precipitation in the tropics and subtropics remains very large, both in the models and the observationally-constrained datasets. Consistent with CMIP3 results, CMIP5 cold extremes generally warm faster than warm extremes, mainly in regions where snow and sea-ice retreat with global warming. There are tropical and subtropical regions where warming rates of warm extremes exceed those of cold extremes. Relative changes in the intensity of precipitation extremes generally exceed relative changes in annual mean precipitation. The corresponding waiting times for late 20th century extreme precipitation events are reduced almost everywhere, except for a few subtropical regions. The CMIP5 planetary sensitivity in extreme precipitation is about 6 %/°C, with generally lower values over extratropical land.     

The 20th century cooling trend over the southeastern United States

Portions of the southern and southeastern United States, primarily Mississippi, Alabama, and Georgia, have experienced century-long (1895–2007) downward air temperature trends that occur in all seasons. Superimposed on them are shifts in mean temperatures on decadal scales characterized by alternating warm (1930s–1940s, 1990s) and cold (1900s; 1960s–1970s) regimes. Regional atmospheric circulation and SST teleconnection indices, station-based cloud cover and soil moisture (Palmer drought severity index) data are used in stepwise multiple linear regression models. These models identify predictors linked to observed winter, summer, and annual Southeastern air temperature variability, the observed variance (r²) they explain, and the resulting prediction and residual time series. Long-term variations and trends in tropical Pacific sea temperatures, cloud cover, soil moisture and the North Atlantic and Arctic oscillations account for much of the air temperature downtrends. Soil moisture and cloud cover are the primary predictors of 59.6 % of the observed summer temperature variance. While the teleconnections, cloud cover and moisture data account for some of the annual and summer Southeastern cooling trend, large significant downward trending residuals remain in winter and summer. Comparison is made to the northeastern United States where large twentieth century upward air temperature trends are driven by cloud cover increases and Atlantic Multidecadal Oscillation (AMO) variability. Differences between the Northeastern warming and the Southeastern cooling trends in summer are attributable in part to the differing roles of cloud cover, soil moisture, the Arctic Oscillation and the AMO on air temperatures of the 2 regions.     

Spatial and temporal variation in daily temperature indices in summer and winter seasons over India (1969–2012)

Spatial and temporal variations in summer and winter extreme temperature indices are studied by using daily maximum and minimum temperatures data from 227 surface meteorological stations well distributed over India for the period 1969–2012. For this purpose, time series for six extreme temperature indices namely, hot days (HD), very hot days (VHD), extremely hot days (EHD), cold nights (CN), very cold nights (VCN), and extremely cold nights (ECN) are calculated for all the stations. In addition, time series for mean extreme temperature indices of summer and winter seasons are also analyzed. Study reveals high variability in spatial distribution of threshold temperatures of extreme temperature indices over the country. In general, increasing trends are observed in summer hot days indices and decreasing trends in winter cold night indices over most parts of the country. The results obtained in this study indicate warming in summer maximum and winter minimum temperatures over India. Averaged over India, trends in summer hot days indices HD, VHD, and EHD are significantly increasing (+1.0, +0.64, and +0.32 days/decade, respectively) and winter cold night indices CN, VCN, and ECN are significantly decreasing (−0.93, −0.47, and −0.15 days/decade, respectively). Also, it is observed that the impact of extreme temperature is higher along the west coast for summer and east coast for winter.

     

概率密度分布法在“一带一路”地区极端月气温评估和预估中的应用

“一带一路”地区人口众多,气候类型复杂,亟待加强区域气候变化风险的认识。文中将该区分成10个区域,基于第五次耦合模式比较计划（CMIP5）中的31个全球模式模拟结果,应用概率密度分布（PDF）方法评估历史阶段（1986—2005年）各模式模拟暖月和冷月气温的能力,挑选并建立较优模式集合,用以预估21世纪中叶（2041—2060年）和21世纪末（2081—2100年）的极端月气温。结果表明,模式对观测中冷月气温距平PDF的模拟水平整体较暖月高。与多模式平均以及中位值相比,较优模式集合方法更适于极端暖/冷月气温的评估。在中等排放RCP4.5情景下,与低纬度地区相比,较优模式模拟中高纬地区未来极端暖/冷月气温的增温幅度的不确定性范围较大。21世纪中叶和21世纪末较优模式模拟的极端暖月气温在地中海增幅整体最大,东南亚增幅整体最小。对较优模式集合预估的极端冷月气温而言,无论是21世纪中叶还是世纪末,北欧增幅整体最大,东南亚增幅整体最小。     

An Amplified Signal of Climatic Change in Soil Temperatures during the Last Century at Irkutsk, Russia

Climatic changes at the Earth's surface propagate slowly downward into theground and modify the ambient ground thermal regime. However, causes of soiltemperature changes in the upper few meters are not well documented. One majorobstacle to understanding the linkage between the soil thermal regime andclimatic change is the lack of long-term observations of soil temperatures andrelated climatic variables. Such measurements were made throughout the formerSoviet Union with some records beginning at the end of the 19th century. Inthis paper, we use records from Irkutsk, Russia, to demonstrate how the soiltemperature responded to climatic changes over the last century. Both airtemperature and precipitation at Irkutsk increased from the late 1890s to the1990s. Changes in air temperature mainly occurred in winter, while changes inprecipitation happened mainly during summer. There was an anti-correlationbetween mean annual air temperature and annual total precipitation, i.e., more(less) precipitation during cold (warm) years. There were no significanttrends of changes in the first day of snow on the ground in autumn, but snowsteadily disappeared earlier in spring, resulting in a reduction of the snowcover duration. A grass-covered soil experiences seasonal freezing for morethan nine months each year and the long-term average maximum depth ofseasonally frozen soils was about 177 cm with a range from 91 cm to 260 cm.The relatively lower soil temperature at shallow depths appears to representthe so-called `thermal offset' in seasonally frozen soils. Changes in meanannual air temperature and soil temperature at 40 cm depth were about the samemagnitude (2.0 °C to 2.5 °C) over the common period of record, but thepatterns of change were substantially different. Mean annual air temperatureincreased slightly until the 1960s, while mean annual soil temperatureincreased steadily throughout the entire period. This leads to the conclusionthat changes in air temperature alone cannot explain the changes in soiltemperatures at this station. Soil temperature actually decreased duringsummer months by up to 4 °C, while air temperature increased slightly.This cooling in the soil may be explained by changes in rainfall and hencesoil moisture during summer due to the effect of a soil moisture feedbackmechanism. While air temperature increased about 4 °C to 6 °C duringwinter, soil temperature increased by up to 9 °C. An increase in snowfallduring early winter (October and November) and early snowmelt in spring mayplay a major role in the increase of soil temperatures through the effects ofinsulation and albedo changes. Due to its relatively higher thermalconductivity compared to unfrozen soils, seasonally frozen ground may enhancethe soil cooling, especially in autumn and winter when thermal gradient isnegative.     

The Use of Indices to Identify Changes in Climatic Extremes

Changes in the frequencies of extremes are investigated by a variety of methods using daily temperature data from the British Isles, and monthly 5° latitude × 5° longitude grid-box temperatures over the land and marine regions of the world. The 225 year long daily Central England Temperature record shows no significant increase in very warm days in recent years but there is a marked decrease in the frequency of very cold days. Thus the rise in temperature in the last two decades is principally associated with a reduction in very cold days. Temperatures on days with particular wind circulation or pressure pattern types over the British Isles show multidecadal variations. Analyses using monthly gridded temperature data around the world since 1951 indicate that the recent rise in global surface temperatures is accompanied both by reductions in the areas affected by extremely cool temperatures and by increases in the areas with extremely warm temperatures.     

Observed Changes in One-in-20 Year Extremes of Canadian Surface Air Temperatures

Weather and climate extremes are often associated with substantial adverse impacts on society and the environment. Assessment of changes in extremes is of great and broad interest. This study first homogenizes daily minimum and maximum surface air temperatures recorded at 146 stations in Canada. In order to assess changes in one-in-20 year extremes (i.e., extremes with a 20-year return period) in temperature, annual maxima and minima of both daily minimum temperatures and daily maximum temperatures are derived from the homogenized daily temperature series and analyzed with a recently developed extreme value analysis approach based on a tree of generalized extreme value distributions (including stationary and non-stationary cases). The procedure is applied to estimate the changes over the period 1911 to 2010 at 115 stations, located mainly in southern Canada, and over the period 1961 to 2010 at 146 stations across Canada (including 37 stations in the North). The results show that warming is strongest for extreme low temperature and weakest for extreme high temperature and is much stronger in the Canadian Arctic than in southern Canada. Warming is stronger in winter than in summer and stronger during nighttime than daytime of the same season.     

Changing climate extremes in the Northeast United States: observations and projections from CMIP5

Climate extremes indices are evaluated for the northeast United States and adjacent Canada (Northeast) using gridded observations and twenty-three CMIP5 coupled models. Previous results have demonstrated observed increases in warm and wet extremes and decreases in cold extremes, consistent with changes expected in a warming world. Here, a significant shift is found in the distribution of observed total annual precipitation over 1981-2010. In addition, significant positive trends are seen in all observed wet precipitation indices over 1951-2010. For the Northeast region, CMIP5 models project significant shifts in the distributions of most temperature and precipitation indices by 2041-2070. By the late century, the coldest (driest) future extremes are projected to be warmer (wetter) than the warmest (wettest) extremes at present. The multimodel interquartile range compares well with observations, providing a measure of confidence in the projections in this region. Spatial analysis suggests that the largest increases in heavy precipitation extremes are projected for northern, coastal, and mountainous areas. Results suggest that the projected increase in total annual precipitation is strongly influenced by increases in winter wet extremes. The largest decreases in cold extremes are projected for northern and interior portions of the Northeast, while the largest increases in summer warm extremes are projected for densely populated southern, central, and coastal areas. This study provides a regional analysis and verification of the latest generation of CMIP global models specifically for the Northeast, useful to stakeholders focused on understanding and adapting to climate change and its impacts in the region.