Search

The article offers information on the global condition of alpine glaciers and ice sheets in 2015. Topics include the World Glacier Monitoring Service (WGMS) mass balance of glaciers, rise of sea level due to the volume loss of alpine glaciers, and negative mass balances in European Alps caused by hot summer.

Life on Earth vitally depends on the availability of water. Human pressure on freshwater resources is increasing, as is human exposure to weather-related extremes (droughts, storms, floods) caused by climate change. Understanding these changes is pivotal for developing mitigation and adaptation strategies. The Global Climate Observing System (GCOS) defines a suite of essential climate variables (ECVs), many related to the water cycle, required to systematically monitor Earth's climate system. Since long-term observations of these ECVs are derived from different observation techniques, platforms, instruments, and retrieval algorithms, they often lack the accuracy, completeness, and resolution, to consistently characterize water cycle variability at multiple spatial and temporal scales. Here, we review the capability of ground-based and remotely sensed observations of water cycle ECVs to consistently observe the hydrological cycle. We evaluate the relevant land, atmosphere, and ocean water storages and the fluxes between them, including anthropogenic water use. Particularly, we assess how well they close on multiple temporal and spatial scales. On this basis, we discuss gaps in observation systems and formulate guidelines for future water cycle observation strategies. We conclude that, while long-term water cycle monitoring has greatly advanced in the past, many observational gaps still need to be overcome to close the water budget and enable a comprehensive and consistent assessment across scales. Trends in water cycle components can only be observed with great uncertainty, mainly due to insufficient length and homogeneity. An advanced closure of the water cycle requires improved model–data synthesis capabilities, particularly at regional to local scales. [ABSTRACT FROM AUTHOR]

The World Meteorological Organization has developed a set of headline indicators for global climate monitoring. These seven indicators are a subset of the existing set of essential climate variables (ECVs) established by the Global Climate Observing System and are intended to provide the most essential parameters representing the state of the climate system. These indicators include global mean surface temperature, global ocean heat content, state of ocean acidification, glacier mass balance, Arctic and Antarctic sea ice extent, global CO2 mole fraction, and global mean sea level. This paper describes how well each of these indicators are currently monitored, including the number and quality of the underlying datasets; the health of those datasets; observation systems used to estimate each indicator; the timeliness of information; and how well recent values can be linked to preindustrial conditions. These aspects vary widely between indicators. While global mean surface temperature is available in close to real time and changes from preindustrial levels can be determined with relatively low uncertainty, this is not the case for many other indicators. Some indicators (e.g., sea ice extent) are largely dependent on satellite data only available in the last 40 years, while some (e.g., ocean acidification) have limited underlying observational bases, and others (e.g., glacial mass balance) with data only available a year or more in arrears. [ABSTRACT FROM AUTHOR]

In 2016, the dominant greenhouse gases released into Earth's Atmosphere--carbon dioxide, methane, and nitrous oxide--continued to increase and reach new record highs. The 3.5 ± 0.1 ppm rise in global annual mean carbon dioxide from 2015 to 2016 was the largest annual increase observed in the 58- year measurement record. The annual global average carbon dioxide concentration at Earth's surface surpassed 400 ppm (402.9 ± 0.1 ppm) for the first time in the modern atmospheric measurement record and in ice core records dating back as far as 800 000 years. One of the strongest El Niño events since at least 1950 dissipated in spring, and a weak La Niña evolved later in the year. Owing at least in part to the combination of El Niño conditions early in the year and a long-term upward trend, Earth's surface observed record warmth for a third consecutive year, albeit by a much slimmer margin than by which that record was set in 2015. Above Earth's surface, the annual lower troposphere temperature was record high according to all datasets analyzed, while the lower stratospheric temperature was record low according to most of the in situ and satellite datasets. Several countries, including Mexico and India, reported record high annual temperatures while many others observed near-record highs. A week-long heat wave at the end of April over the northern and eastern Indian peninsula, with temperatures surpassing 44°C, contributed to a water crisis for 330 million people and to 300 fatalities. In the Arctic the 2016 land surface temperature was 2.0°C above the 1981-2010 average, breaking the previous record of 2007, 2011, and 2015 by 0.8°C, representing a 3.5°C increase since the record began in 1900. The increasing temperatures have led to decreasing Arctic sea ice extent and thickness. On 24 March, the sea ice extent at the end of the growth season saw its lowest maximum in the 37-year satellite record, tying with 2015 at 7.2% below the 1981-2010 average. The September 2016 Arctic sea ice minimum extent tied with 2007 for the second lowest value on record, 33% lower than the 1981-2010 average. Arctic sea ice cover remains relatively young and thin, making it vulnerable to continued extensive melt. The mass of the Greenland Ice Sheet, which has the capacity to contribute ~7 m to sea level rise, reached a record low value. The onset of its surface melt was the second earliest, after 2012, in the 37-year satellite record. Sea surface temperature was record high at the global scale, surpassing the previous record of 2015 by about 0.01°C. The global sea surface temperature trend for the 21st century-to-date of +0.162°C decade-1 is much higher than the longer term 1950-2016 trend of +0.100°C decade-1. Global annual mean sea level also reached a new record high, marking the sixth consecutive year of increase. Global annual ocean heat content saw a slight drop compared to the record high in 2015. Alpine glacier retreat continued around the globe, and preliminary data indicate that 2016 is the 37th consecutive year of negative annual mass balance. Across the Northern Hemisphere, snow cover for each month from February to June was among its four least extensive in the 47-year satellite record. Continuing a pattern below the surface, record high temperatures at 20-m depth were measured at all permafrost observatories on the North Slope of Alaska and at the Canadian observatory on northernmost Ellesmere Island. In the Antarctic, record low monthly surface pressures were broken at many stations, with the southern annular mode setting record high index values in March and June. Monthly high surface pressure records for August and November were set at several stations. During this period, record low daily and monthly sea ice extents were observed, with the November mean sea ice extent more than 5 standard deviations below the 1981-2010 average. These record low sea ice values contrast sharply with the record high values observed during 2012-14. Over the region, springtime Antarctic stratospheric ozone depletion was less severe relative to the 1991-2006 average, but ozone levels were still low compared to pre-1990 levels. Closer to the equator, 93 named tropical storms were observed during 2016, above the 1981-2010 average of 82, but fewer than the 101 storms recorded in 2015. Three basins--the North Atlantic, and eastern and western North Pacific--experienced above-normal activity in 2016. The Australian basin recorded its least active season since the beginning of the satellite era in 1970. Overall, four tropical cyclones reached the Saffir--Simpson category 5 intensity level. The strong El Niño at the beginning of the year that transitioned to a weak La Niña contributed to enhanced precipitation variability around the world. Wet conditions were observed throughout the year across southern South America, causing repeated heavy flooding in Argentina, Paraguay, and Uruguay. Wetter-than-usual conditions were also observed for eastern Europe and central Asia, alleviating the drought conditions of 2014 and 2015 in southern Russia. In the United States, California had its first wetter-than-average year since 2012, after being plagued by drought for several years. Even so, the area covered by drought in 2016 at the global scale was among the largest in the post-1950 record. For each month, at least 12% of land surfaces experienced severe drought conditions or worse, the longest such stretch in the record. In northeastern Brazil, drought conditions were observed for the fifth consecutive year, making this the longest drought on record in the region. Dry conditions were also observed in western Bolivia and Peru; it was Bolivia's worst drought in the past 25 years. In May, with abnormally warm and dry conditions already prevailing over western Canada for about a year, the human-induced Fort McMurray wildfire burned nearly 590 000 hectares and became the costliest disaster in Canadian history, with $3 billion (U.S. dollars) in insured losses. [ABSTRACT FROM AUTHOR]

The article focuses on the temperature and amount of rainfall in New Zealand in 2015 and presents an appendix of datasets and sources for general phenomenon or variable. Topics discussed include the observed above-average temperature anomalies in January and March, the low annual rainfall total in 2015 which was typically observed during El Niño, and the flooding, loss of electricity, and road closures caused by heavy and prolonged rainfall in Dunedin.

The article offers information on the condition of glaciers and ice caps outside Greenland in 2015. Topics include mass gain of glaciers and ice caps due to snow accumulation, measurements of total mass balance for glaciers and ice caps in Arctic Canada and the Russian Arctic region, and mass loss of glaciers and ice caps due to surface melt runoff and iceberg calving.

In 2015, the dominant greenhouse gases released into Earth's atmosphere—carbon dioxide, methane, and nitrous oxide—all continued to reach new high levels. At Mauna Loa, Hawaii, the annual CO2 concentration increased by a record 3.1 ppm, exceeding 400 ppm for the first time on record. The 2015 global CO2 average neared this threshold, at 399.4 ppm. Additionally, one of the strongest El Niño events since at least 1950 developed in spring 2015 and continued to evolve through the year. The phenomenon was far reaching, impacting many regions across the globe and affecting most aspects of the climate system. Owing to the combination of El Niño and a long-term upward trend, Earth observed record warmth for the second consecutive year, with the 2015 annual global surface temperature surpassing the previous record by more than 0.1°C and exceeding the average for the mid- to late 19th century—commonly considered representative of preindustrial conditions—by more than 1°C for the first time. Above Earth's surface, lower troposphere temperatures were near-record high. Across land surfaces, record to near-record warmth was reported across every inhabited continent. Twelve countries, including Russia and China, reported record high annual temperatures. In June, one of the most severe heat waves since 1980 affected Karachi, Pakistan, claiming over 1000 lives. On 27 October, Vredendal, South Africa, reached 48.4°C, a new global high temperature record for this month. In the Arctic, the 2015 land surface temperature was 1.2°C above the 1981-2010 average, tying 2007 and 2011 for the highest annual temperature and representing a 2.8°C increase since the record began in 1900. Increasing temperatures have led to decreasing Arctic sea ice extent and thickness. On 25 February 2015, the lowest maximum sea ice extent in the 37-year satellite record was observed, 7% below the 1981-2010 average. Mean sea surface temperatures across the Arctic Ocean during August in ice-free regions, representative of Arctic Ocean summer anomalies, ranged from ∼0°C to 8°C above average. As a consequence of sea ice retreat and warming oceans, vast walrus herds in the Pacific Arctic are hauling out on land rather than on sea ice, raising concern about the energetics of females and young animals. Increasing temperatures in the Barents Sea are linked to a community-wide shift in fish populations: boreal communities are now farther north, and long-standing Arctic species have been almost pushed out of the area. Above average sea surface temperatures are not confined to the Arctic. Sea surface temperature for 2015 was record high at the global scale; however, the North Atlantic southeast of Greenland remained colder than average and colder than 2014. Global annual ocean heat content and mean sea level also reached new record highs. The Greenland Ice Sheet, with the capacity to contribute ∼7 m to sea level rise, experienced melting over more than 50% of its surface for the first time since the record melt of 2012. Other aspects of the cryosphere were remarkable. Alpine glacier retreat continued, and preliminary data indicate that 2015 is the 36th consecutive year of negative annual mass balance. Across the Northern Hemisphere, late-spring snow cover extent continued its trend of decline, with June the second lowest in the 49-year satellite record. Below the surface, record high temperatures at 20-m depth were measured at all permafrost observatories on the North Slope of Alaska, increasing by up to 0.66°C decade-1 since 2000. In the Antarctic, surface pressure and temperatures were lower than the 1981-2010 average for most of the year, consistent with the primarily positive southern annular mode, which saw a record high index value of +4.92 in February. Antarctic sea ice extent and area had large intra-annual variability, with a shift from record high levels in May to record low levels in August. Springtime ozone depletion resulted in one of the largest and most persistent Antarctic ozone holes observed since the 1990s. Closer to the equator, 101 named tropical storms were observed in 2015, well above the 1981-2010 average of 82. The eastern/central Pacific had 26 named storms, the most since 1992. The western north Pacific and north and south Indian Ocean basins also saw high activity. Globally, eight tropical cyclones reached the Saffir-Simpson Category 5 intensity level. Overlaying a general increase in the hydrologic cycle, the strong El Niño enhanced precipitation variability around the world. An above-normal rainy season led to major floods in Paraguay, Bolivia, and southern Brazil. In May, the United States recorded its all-time wettest month in its 121-year national record. Denmark and Norway reported their second and third wettest year on record, respectively, but globally soil moisture was below average, terrestrial groundwater storage was the lowest in the 14-year record, and areas in "severe" drought rose from 8% in 2014 to 14% in 2015. Drought conditions prevailed across many Caribbean island nations, Colombia, Venezuela, and northeast Brazil for most of the year. Several South Pacific countries also experienced drought. Lack of rainfall across Ethiopia led to its worst drought in decades and affected millions of people, while prolonged drought in South Africa severely affected agricultural production. Indian summer monsoon rainfall was just 86% of average. Extremely dry conditions in Indonesia resulted in intense and widespread fires during August-November that produced abundant carbonaceous aerosols, carbon monoxide, and ozone. Overall, emissions from tropical Asian biomass burning in 2015 were almost three times the 2001-14 average. [ABSTRACT FROM AUTHOR]

The article offers information on the global climatic conditions in 2014. Various topics discussed include global surface temperature, hydrological cycle, atmospheric circulation, temperature in the North Atlantic region, air temperature in Arctic region, history of floods in Balkan Peninsula and upper ocean stratification.

Climate research, monitoring, prediction, and related services rely on accurate observations of the atmosphere, land, and ocean, adequately sampled globally and over sufficiently long time periods. The Global Climate Observing System, set up under the auspices of United Nations organizations and the International Council for Science to help ensure the availability of systematic observations of climate, developed the concept of essential climate variables (ECVs). ECV data records are intended to provide reliable, traceable, observation-based evidence for a range of applications, including monitoring, mitigating, adapting to, and attributing climate changes, as well as the empirical basis required to understand past, current, and possible future climate variability. The ECV concept has been broadly adopted worldwide as the guiding basis for observing climate, including by the United Nations Framework Convention on Climate Change (UNFCCC), WMO, and space agencies operating Earth observation satellites. This paper describes the rationale for these ECVs and their current selection, based on the principles of feasibility, relevance, and cost effectiveness. It also provides a view of how the ECV concept could evolve as a guide for rational and evidence-based monitoring of climate and environment. Selected examples are discussed to highlight the benefits, limitations, and future evolution of this approach. The article is intended to assist program managers to set priorities for climate observation, dataset generation and related research: for instance, within the emerging Global Framework for Climate Services (GFCS). It also helps the observation community and individual researchers to contribute to systematic climate observation, by promoting understanding of ECV choices and the opportunities to influence their evolution. [ABSTRACT FROM AUTHOR]

Editors note: For easy download the posted pdf of the State of the Climate for 2013 is a very low-resolution file. A high-resolution copy of the report is available by clicking . Please be patient as it may take a few minutes for the high-resolution file to download. [ABSTRACT FROM AUTHOR]

Observations of Earth from space have been made for over 40 years and have contributed to advances in many aspects of climate science. However, attempts to exploit this wealth of data are often hampered by a lack of homogeneity and continuity and by insufficient understanding of the products and their uncertainties. There is, therefore, a need to reassess and reprocess satellite datasets to maximize their usefulness for climate science. The European Space Agency has responded to this need by establishing the Climate Change Initiative (CCI). The CCI will create new climate data records for (currently) 13 essential climate variables (ECVs) and make these open and easily accessible to all. Each ECV project works closely with users to produce time series from the available satellite observations relevant to users' needs. A climate modeling users' group provides a climate system perspective and a forum to bring the data and modeling communities together. This paper presents the CCI program. It outlines its benefit and presents approaches and challenges for each ECV project, covering clouds, aerosols, ozone, greenhouse gases, sea surface temperature, ocean color, sea level, sea ice, land cover, fire, glaciers, soil moisture, and ice sheets. It also discusses how the CCI approach may contribute to defining and shaping future developments in Earth observation for climate science. [ABSTRACT FROM AUTHOR]

For the first time in several years, the El Niño-Southern Oscillation did not dominate regional climate conditions around the globe. A weak La Niña dissipated to ENSO-neutral conditions by spring, and while El Niño appeared to be emerging during summer, this phase never fully developed as sea surface temperatures in the eastern equatorial Pacific uncharacteristically returned to neutral conditions. Nevertheless, other large-scale climate patterns and extreme weather events impacted various regions during the year. A negative phase of the Arctic Oscillation from mid-January to early February contributed to frigid conditions in parts of northern Africa, eastern Europe, and western Asia. A lack of rain during the 2012 wet season led to the worst drought in at least the past three decades for northeastern Brazil. Central North America also experienced one of its most severe droughts on record. The Caribbean observed a very wet dry season and it was the Sahel's wettest rainy season in 50 years. Overall, the 2012 average temperature across global land and ocean surfaces ranked among the 10 warmest years on record. The global land surface temperature alone was also among the 10 warmest on record. In the upper atmosphere, the average stratospheric temperature was record or near-record cold, depending on the dataset. After a 30-year warming trend from 1970 to 1999 for global sea surface temperatures, the period 2000-12 had little further trend. This may be linked to the prevalence of La Niña-like conditions during the 21st century. Heat content in the upper 700 m of the ocean remained near record high levels in 2012, Net increases from 2011 to 2012 were observed at 700-m to 2000-m depth and even in the abyssal ocean below. Following sharp decreases in global sea level in the first half of 2011 that were linked to the effects of La Niña, sea levels rebounded to reach records highs in 2012. The increased hydrological cycle seen in recent years continued, with more evaporation in drier locations and more precipitation in rainy areas. In a pattern that has held since 2004, salty areas of the ocean surfaces and subsurfaces were anomalously salty on average, while fresher areas were anomalously fresh. Global tropical cyclone activity during 2012 was near average, with a total of 84 storms compared with the 1981-2010 average of 89. Similar to 2010 and 2011, the North Atlantic was the only hurricane basin that experienced above-normal activity. In this basin, Sandy brought devastation to Cuba and parts of the eastern North American seaboard. All other basins experienced either near- or below-normal tropical cyclone activity. Only three tropical cyclones reached Category 5 intensity-all in the Western North Pacific basin. Of these, Super Typhoon Bopha became the only storm in the historical record to produce winds greater than 130 kt south of 7°N. It was also the costliest storm to affect the Philippines and killed more than 1000 residents. Minimum Arctic sea ice extent in September and Northern Hemisphere snow cover extent in June both reached new record lows. June snow cover extent is now declining at a faster rate (-17.6% per decade) than September sea ice extent (-13.0% per decade). Permafrost temperatures reached record high values in northernmost Alaska. A new melt extent record occurred on 11-12 July on the Greenland ice sheet; 97% of the ice sheet showed some form of melt, four times greater than the average melt for this time of year. The climate in Antarctica was relatively stable overall. The largest maximum sea ice extent since records begain in 1978 was observed in September 2012. In the stratosphere, warm air led to the second smallest ozone hole in the past two decades. Even so, the springtime ozone layer above Antarctica likely will not return to its early 1980s state until about 2060. Following a slight decline associated with the global financial crisis, global CO2 emissions from fossil fuel combustion and cement production reached a record 9.5 ± 0.5 Pg C in 2011 and a new record of 9.7 ± 0.5 Pg C is estimated for 2012. Atmospheric CO2 concentrations increased by 2.1 ppm in 2012, to 392.6 ppm. In spring 2012, for the first time, the atmospheric CO2 concentration exceeded 400 ppm at 7 of the 13 Arctic observation sites. Globally, other greenhouse gases including methane and nitrous oxide also continued to rise in concentration and the combined effect now represents a 32% increase in radiative forcing over a 1990 baseline. Concentrations of most ozone depleting substances continued to fall. INSET: SIDEBAR 7.5: A VERY WARM END TO THE AUSTRAL SPRING FOR.... [ABSTRACT FROM AUTHOR]

The article provides information related to seasons and climate. It presents several figures that show surface temperature anomalies and precipitation percentiles from December 2007 to November 2008, as well as the geopotential heights and anomalies of the Northern and Southern Hemispheres on the same date range. It also cites several acronyms related to meteorology, such as AO for Arctic Oscillation. It also lists several references that were used in this issue of the journal.

The article offers information on acronyms and abbreviations related to climatology.

The article offers information on the condition of snow cover extent (SCE) in Northern Hemisphere (NH) continents in 2015. Topics include the early arrival of snow over NH continents during autumn 2015, ice sheet in Greenland, and condition of SCE over the U.S. in January. A table is also presented which shows climatological statistics on NH and SCE between November 1966 and December 2015.

A list of the acronyms and abbreviations used in the "2013 State of the Climate" report from the U.S. National Oceanic and Atmospheric Administration (NOAA) is presented, including Antarctic Oscillation, Global Precipitation Climatology Centre, and advanced microwave scanning.

The article examines the patterns, changes and trends in glaciers and ice caps in the Arctic, outside Greenland, in 2013. Topics discussed include the impact of mountain glaciers and ice caps on the global sea level changes, the use of climatic mass balance as an index of how glaciers respond to climate variability and change, and the regional total mass balance estimates for Arctic Canada and Alaska.

The article reports on the mass balance and terminus behavior of Alpine glaciers and ice sheets in 2013. Topics discussed include the negative annual mass balances since 1990, the cumulative mass balance loss since 1980, and the average terminus change of the Austrian glaciers. Also mentioned are the glaciers in Norway, North Cascades in Washington, and New Zealand.

The article focuses on the snow cover extent (SCE) over the Northern Hemisphere continents in 2013. Topics discussed include the monthly mean anomalies during the year in all regions, the early arrival of snow over the Northern Hemisphere, and the SCE advance over North America and the combined continents of Europe and Asia.

PART 3 OF 3 APPENDIX 1: RELEVANT DATASETS AND SOURCES General Variable Specific dataset 2018 Source or Phenomenon or variable Aerosols CAMS Reanalysis https://atmosphere.- copernicus.eu/ Air-sea fluxes CERES Energy https://ceres.larc.- [...]

Part 1 of 3 TABLE OF CONTENTS List of authors and affiliations Abstract 1. INTRODUCTION SIDEBAR 1.1: ESSENTIAL CLIMATE VARIABLES 2. GLOBAL CLIMATE a. Overview b. Temperature 1. Global surface [...]

Abernethy, R., J. Garforth, D. Hemming, M. Kendon, M. McCarthy, and T. Sparks, 2017: State of the UK Climate 2016: Phenology supplement. 39 pp., www.metoffice.gov.uk/binaries/content/assets/mohippo/pdf/uk-climate/ state-of-the-uk-climate/mo-phenology-supplement-v4.pdf. Abraham, J. P., and [...]

a. Introduction--E. Osborne, J. Richter-Menge, and M. O. Jeffries Annual average Arctic air temperatures (above 60[degrees]N) in 2017 continued to increase at twice the rate of the rest of the [...]

a. Overview--R. J. H. Dunn, D. M. Stanitski, N. Gobron, and K. M. Willett The global land and ocean surface temperature was remarkably high in 2017. Depending on the dataset [...]

APPENDIX I: SEASONAL SUMMARIES APPENDIX 2: RELEVANT DATASETS AND SOURCES General Specific Variable or Dataset or Phenomenon Variable Source Section Aerosols Aerosol http://www.copernicus- 2g3 products atmosphere.eu/data Air-sea Woods Hole http://oaflux.whoi.edu [...]

5) Western Indian Ocean countries--Z. Rakotomavo and G. Jumaux This region is made of many islands grouped into five countries, including Comoros, Madagascar, Mauritius, Seychelles, and Reunion (France). Here the [...]