Observations and analysis of climate and its changes

Transcription

1 1 ISCS, Chengdu, 18 July 2016 Observations and analysis of climate and its changes 1. The systematic observation of climate: its nature and status Adrian Simmons Former Head of Data Division and Consultant to the Copernicus Climate Change Service at the European Centre for Medium-Range Weather Forecasts Former Chair, Steering Committee for GCOS

2 2 Observations and analysis of climate and its changes 1. The systematic observation of climate: its nature and status 2. Observational analysis and reanalysis, and Europe s Copernicus services on climate change and atmospheric monitoring 3. Estimating variability and change in global temperature, and the extreme 2015/16 warm spell 4. Current progress in reanalysis at ECMWF

3 What is systematic observation of climate? The word systematic can mean: methodical orderly regular organised efficient Systematic can also mean: involving or observing a system and for the climate system requires: sustaining observation over decades and more, and managing change in observational methods and locations 3

4 4 Observations of the climate system Cover a wide range of atmospheric, oceanic and terrestrial variables and are subject to a diverse set of institutional arrangements Are made either directly in place (in situ) or by remote sensing with space-based remote sensing providing a substantial component Are made with varying degrees of maturity from centennial-scale weather records to emerging capabilities for autonomous sensing of the sub-surface ocean, for example Need to be complemented by socio-economic data to develop products and services for application sectors for estimates of anthropogenic emissions

5 5 Observations of the climate system May serve several purposes and be used repeatedly over many years e.g. for initialising and then verifying weather forecasts, estimating climate trends and evaluating climate models May be used most effectively only after many years, sometimes in originally unforeseen ways e.g. the radiance data from early satellites or the century-old observations from ships that are now used in reanalysis Are prone to biases and changes in instruments and coverage that need to be taken into account in many applications May be processed and re-processed, and integrated in various products including those dedicated to a single instrument or variable, or comprehensive reanalyses using multi-variate data assimilation

6 6 Institutional framework Observation and product providers National Meteorological and Hydrological Services National institutions responsible for oceanographic or terrestrial observation National and European space agencies National data centres Regional centres Coordinating systems or bodies WMO observing systems (WIGOS: GOS, GAW, GCW, WHOS) IOC-led co-sponsored Global Ocean Observing System (GOOS) Research programmes (WCRP,...) Other bodies dealing with observations, data management or products (CEOS, CGMS, ) GCOS covers the climate-observation components of these systems It functions through both specific GCOS bodies and the data providers is sponsored by

7 7 The GCOS programme identifies requirements for the observing systems that in combination provide our overall global observing system for climate recommends and reviews actions by data providers, sponsors and programmes reports mainly to its sponsors, and by invitation to the Parties to the United Nations Framework Convention on Climate Change (UNFCCC) in particular through: a 2003 report on the adequacy of observation, and a 2004 implementation plan identifying required actions and who might undertake them a 2009 review of progress, and a 2010 revision of the implementation plan the 2015 status report and a new implementation plan to be published later this year

8 8 Organisational framework: The Essential Climate Variables Observations may be organised by: variable (temperature, CO 2, ) observing network or system (WMO Regional Basic Climatological Network, Argo profiling float network, FY-3 satellite system, ) physical/chemical cycle (energy cycle, hydrological cycle, carbon cycle, ) societal benefit area (agriculture, water supply, energy supply, ) Primary organisational framework for GCOS is based on variables: a set of Essential Climate Variables (ECVs) in particular although networks, cycles and applications are all taken into consideration

9 The Essential Climate Variables Atmospheric Oceanic Terrestrial Surface: Air temperature, wind speed and direction, water vapour, pressure, precipitation, surface radiation budget Upper-air: Temperature, wind speed and direction, water vapour, cloud properties, earth radiation budget (including solar irradiance) Composition: Carbon dioxide, methane, other long-lived greenhouse gases, ozone and aerosol, supported by their precursors Surface: Sea-surface temperature, sea-surface salinity, sea level, sea state, sea ice, surface current, ocean colour, carbon dioxide partial pressure, ocean acidity, phytoplankton Sub-surface: Temperature, salinity, current, nutrients, carbon dioxide partial pressure, ocean acidity, oxygen, tracers River discharge, water use, groundwater, lakes, snow cover, glaciers and ice caps, ice sheets, permafrost, albedo, land cover (including vegetation type), fraction of absorbed photosynthetically active radiation, leaf area index, aboveground biomass, soil carbon, fire disturbance, soil moisture From the 2010 Implementation Plan to be revised a little in the 2016 Plan 9

10 10 What did we provide in the report? The background to the report itself An introduction to climate observation An account of the current status and established planning of the main contributing observing systems and networks, and of related product generation and assessment, and data management Accounts of the importance and observational status of each of the 51 ECVs listed in the 2010 Implementation Plan Reviews of the 138 actions set out in the 2010 Plan Key conclusions and discussions that point to some of the areas now being followed up in preparing the new Implementation Plan

11 11 Space-based observing systems The first cloud images from space were made from TIROS-1, launched 1 April 1960 Nimbus 4 8 April 1970 Several types of observation that have been sustained to the present time were initiated in the 1970s They include data on: ozone from back-scattered ultraviolet radiation Landsat 1 23 July 1972 land-surface conditions from visible images temperature and humidity from infrared sounding temperature from microwave sounding sea-ice cover from microwave imagery winds from tracking cloud images NOAA 2 15 Oct 1972

12 Example: Action T28 from 2010 Plan Generate global land cover maps based on 10-30m imagery every 5 years Shown here for an area including Beijing and Tianjin, and for the Amazon A 30m product for forests has been produced by the University of Maryland, and a 30m product for surface water by the EC Joint Research Centre 12

13 Example: Action T28 from 2010 Plan Generate global land cover maps based on 10-30m imagery every 5 years Challenges and opportunities are for further validation, refinement of classification, use of improved imagery, e.g. from Sentinel-2, reprocessing and updating 13

14 14 Evolution of the space-based observing system Operational meteorological satellites: have flown in polar and geostationary orbit since the 1970s with international collaboration fundamental for geostationary systems from the outset with European polar orbiters as well as US polar platforms from 2006 with China becoming established as the provider of a third pillar in the constellation of polar orbiters with a general increase over time in the quality and types of instrument flown and a recognised role now for climate monitoring as well as weather prediction

15 15 Evolution of the space-based observing system Copernicus Sentinels put other types of observation on an operational footing: for atmosphere, ocean and land for climate and environmental monitoring with associated services and an open data policy

16 Example: Sea-ice extent From daily US National Ice and Snow Data Center Sea Ice Index, based on passive microwave imagery from SMMR, SSMI and SSMIS instruments 16

17 17 Example: Ice-sheet mass balance Estimates of ice-sheet mass change using space-based gravimetry, laser and radar altimetry, interferometry and surface mass balance modelling, made by the ESA/NASA funded IMBIE project (Shepherd et al.; 2012)

18 18 Example: Budget of global-mean sea-level rise From WGI contribution to IPCC AR5. Units are mm/year Storage in reservoirs dominates Depletion of groundwater dominates

19 19 Example: Lake and reservoir levels Satellite altimetry from THEIA HYDROWEB site (Crétaux et al., 2011) In situ measurements from US Bureau of Reclamation website (not available from International Data Centre for Hydrology of Lakes and Reservoirs)

20 20 Some issues over continuity of space-based observation For well-established types of measurement, concerns include: continuity of microwave measurements of sea-surface temperature lack of provision for continued limb-emission measurement adequacy of monitoring of the radiation budget adequacy of coverage by GNSS receivers for radio occultation measurements lack of provision of scatterometry from the afternoon orbit continuity and resolution of measurements of variations in gravity Continuity, or intermittent enhanced missions for specific R&D purposes? what should the balance be, for example for cloud/aerosol measurement? What next for measurements that are emerging or may emerge as important? ocean salinity, soil moisture, CO 2, fluorescence, biomass, winds, surface water, How serious is the absence of a reference mission providing long-term and well-calibrated radiance measurements? given the stability of high resolution infrared sounders and radio occultation, and in situ reference measurement

21 21 Some ways in which progress and current status were assessed By gathering information from GCOS panel members and other experts, and from the plans of data providers By drawing on conclusions of workshops and symposia, and national communications to the UNFCCC By evaluating responses to actions from 2010 GCOS Implementation Plan By evaluating network performance and data-centre holdings By relating to key uncertainties identified in IPCC AR5 Confidence in global precipitation change over land is low prior to 1951 and medium afterwards because of data incompleteness. By accumulating evidence of improvements in observational quality

22 22 Some ways in which progress and current status were assessed By gathering information from GCOS panel members and other experts, and from the plans of data providers By drawing on conclusions of workshops and symposia, and national communications to the UNFCCC By evaluating responses to actions from 2010 GCOS Implementation Plan By evaluating network performance and data-centre holdings By relating to key uncertainties identified in IPCC AR5 Confidence in global precipitation change over land is low prior to 1951 and medium afterwards because of data incompleteness. By accumulating evidence of improvements in observational quality

23 23 Some ways in which progress and current status were assessed, especially for data from atmospheric networks By evaluating responses to actions from the 2010 Implementation Plan Action A2: Action A3: Obtain further progress in the systematic international exchange of hourly SYNOP reports and monthly CLIMAT reports... Ensure sustained operation of surface meteorological stations addressing national and sub-national needs implement additional stations where necessary... Action C13: Collect, digitize and analyse historical data records and submit to International Data Centres By evaluating network performance and data-centre holdings Examining holdings of the recognised international data centres, especially the lead archive centre for GCOS (NOAA NCEI) Examining ECMWF data holdings from near-real-time data flows and collections for reanalysis, and comparing them with NCEI and other data-centre holdings

24 24 Availability of synoptic and monthly surface meteorological data Amounts of synoptic data held by ECMWF and monthly data held by NCEI are higher for more-recent years Increases for synoptic data have occurred in both station numbers and reporting frequency Coverage limitations may be due to limited international data transmission, not lack of measurement But some gaps persist over time and across variables High-frequency data are required for studies of extremes and adaptation More-widespread hourly data are provided in less-precise airport code There is now some regional transmission of hourly precipitation from synoptic stations

25 More on the networks and archives for atmospheric data There is progress in the recovery and sharing of older data, but scope for more to be done, including archive improvements Radiosonde data counts and coverage have improved Good global coverage tends to be lacking for reference and baseline networks Observing systems for atmospheric composition pose some particular challenges 25

26 26 Ocean networks Voluntary Observing Ships XBT and other data from ships of opportunity Drifting buoys Profilin g floats Moored buoys Hydrographic section s

27 27 Performance of buoy networks Good increase over time in number of observations from drifting buoys, but drop in 2012 due to shorter buoy lifetimes. Little progress on increasing deployment of barometers on drifting buoys Drop in data return from moorings in the eastern tropical Pacific Ocean in 2012 and 2013 due to reduced maintenance

28 Development of network of Argo floats was highlighted 28

29 International contributions to the Argo network Network was built up to its original design target of 3000 floats in 2007 Developments include deployment in marginal seas, rugged floats designs that can cope with ice cover, and faster communications enabling shorter stays at the surface 29

30 Floats with biogeochemical sensors, or reaching depths well below 2000m Developments include floats that can sample much deeper than 2000m, some to 6000m, and development of sensors for biogeochemical variables such as oxygen, nitrate, chlorophyll a, particulate matter and acidity 30

31 Networks of observations for specific variables Proposed baseline Global Terrestrial Network for River Discharge Programmes contributing to the Global Alliance of Continuous Plankton Recorder Surveys network Mean annual glacier mass balance, based on 37 glaciers with continuous records, from ten mountain ranges 31

32 32 Some of ways in which progress and current status were assessed By gathering information from GCOS panel members and other experts, and from the plans of data providers By drawing on conclusions of workshops and symposia, and national communications to the UNFCCC By evaluating responses to actions from 2010 GCOS Implementation Plan By evaluating network performance and data-centre holdings By relating to key uncertainties identified in IPCC AR5 Confidence in global precipitation change over land is low prior to 1951 and medium afterwards because of data incompleteness. By accumulating evidence of improvements in observational quality

33 Station distributions for monthly products of the Global Precipitation Climatology Centre Lengths of record for ~75000 stations in GPCC database Increase in station numbers over 7 years is 35-40% before1950s, and ~60% in 1970s Many data are supplied only after several years Locations providing daily or monthly data on the GTS for October 2014 Increase over 7 years is ~20% Number of stations is currently ~

34 1 O x1 O grid boxes with at least one station in version 7 of GPCC full data monthly product Some scope remains for pre-1951 data recovery, but how much? How well can the global picture be constructed using good observational coverage in some regions along with modelling? 34

35 35 Improvements over time in observations Smaller estimated radiosonde biases L. Haimberger Smaller spread among data from different types of radiosonde from WMO comparisons R. Philipona Smaller estimated biases in soundings from satellites Much smaller drift in equatorial crossing times for sun-synchronous satellites And better fits of observations to data assimilation background fields better reporting codes for some meteorological observations

36 36 Some of ways in which progress and current status were assessed By gathering information from panel members and other experts, and from the plans of data providers By drawing on conclusions of workshops and symposia, and national communications to the UNFCCC By evaluating responses to actions from 2010 GCOS Implementation Plan By evaluating network performance and data-centre holdings By relating to key uncertainties identified in IPCC AR5 By accumulating evidence of improvements in observational quality By showing availability of data products using providers visualization tools

37 Methane and other greenhouse gases (including some ozone-depleting species controlled under the Montreal Protocol) Plotted interactively at NOAA/ESRL website Data downloaded from NOAA/ESRL website 37

38 Albedo, Leaf Area Index and Fraction of Absorbed Photosynthetically Active Radiation Combined NASA Terra/Aqua MODIS albedo product based on data acquired between 23 April and 8 May 2015, plotted as an 8x3 mosaic of downloaded browse tiles LAI and FAPAR based on data from the PROBA-V satellite dated 3 May 2015 Quick-look images provided by the Copernicus Global Land Service 38

39 Land cover near Lake Geneva from the ESA Climate Change Initiative and the National Geomatics Center of China Up to 29 types 300m resolution 10 types 30m resolution 39

40 40 Some other conclusions of the report Reprocessing of data and generation of data products, for individual ECVs and from reanalysis, continues to improve and expand; opportunities include recovery of data from early satellite missions Access to data is improving, but still an issue Capacity development continues to fall far short of what is needed to fill critical network gaps Sustaining activities initiated with short-term research funding is a recurrent issue Assessed progress of 138 IP-10 Actions International organisation has been strengthened for atmosphere and ocean, but has weakened for terrestrial observation