Ocean-atmosphere cross-cutting observation needs. Elizabeth Kent

Transcription

1 Ocean-atmosphere cross-cutting observation needs Elizabeth Kent

2 What information is needed for the atmosphere over the ocean?

3 Atmospheric ECVs

4 Intergovernmental Panel on Climate Change, 5 th Assessment Report, 2013 How do we know the world is warming? SST: ships, moored buoys, drifters Air temperature: ships, moored buoys Humidity : ships, moored buoys

5 RRR gives requirements for different applications

6 AOPC requirements for near surface air temp.

7 GCOS: Implementation Needs, 2016

8 GCOS: Implementation Needs, 2016

9 GCOS: Implementation Needs, 2016

10 GCOS: Implementation Needs, 2016

11 Reporting of status of ocean observing system GOOS/GCOS 2010 implementation goals for climate observations continuous satellite measurements of sea surface temperature, height, winds, ocean color, and sea ice Total in situ networks 66% June 2016 Surface measurements 100% from volunteer ships (VOS) 250 ships in VOSclim pilot project 100% Global drifting surface buoy array ice buoys 5 resolution array: 1250 floats 40% Tide gauge network (GLOSS committed) Fast data Slow/no data 39% 300 real-time reporting gauges GPS XBT sub-surface temperature section network XBTs deployed 100% Argo profiling float network 3 resolution array: 3200 floats 66% Global time series network 87 combined sites 76% Global tropical moored buoy network 125 moorings planned 62% Repeat hydrography and carbon inventory (Planned) Full ocean survey in 10 years Representative Milestones 100% Original goal for full implementation by % % 2014 System % sustained, of initial goals

12 JCOMMOPS produce metrics/kpi 1.39% in June % in March 2017

13 Requirements from climate product developers Journal papers describing climate product development contain recommendations for improving the data more data, historical and modern need to identify individual platforms (callsign masking a huge problem) need observational metadata (Pub. 47 up-to-date and linkable to obs.) multivariate observations most useful multiple platforms and platform types needed for characterisation quick changes of observation types problematic need overlap

14 Uncertainty estimation for marine air temperature height adjustment for height adjustment with low uncertainty need: observations with known heights, from platforms with identifiers, multi-variate obs. for air-temperature with low uncertainty also need: observations with good accuracy, and/or many different platforms with good sampling of conditions in the grid-box

15 How can adequacy be assessed?

16 Simple metric for single application Journal of Atmospheric and Oceanic Technology

17 Simple metric for single ECV and application

18 Simple metrics -> impact Platform or observations counts and coverage estimates are easy to calculate. platform counts particularly easy for system design When budgets are tight focus on a small number of metrics can have adverse effects on the overall observing system Focus on SST has led to reductions in other parameters including air temperature, humidity and winds Move to automation has led to a smaller number of ships making typically larger number of observations

19 Assessment using methods for gridded products

20 Assessment using methods for gridded products

21 Next steps

22 Better define requirements Use information from marine climate product development to define initial requirements for uncertainty on space and time scales relevant for climate for each ECV The quality and completeness of observations is important do we have all the data and metadata needed to make height or bias adjustments? can the platform be identified? climate applications typically only use information in public domain GCOS tiered approach to observations: reference, baseline and global definitions of these network types needs adaption for marine case tiered requirements likely to be appropriate Work with JCOMM to establish climate KPIs

23 Work with JCOMM to establish climate KPIs The WMO RRR approach has proved problematic: swift delivery isn't always important for climate data products not always desirable to combine all types of observations may want in situ only, or to withhold some high quality data for validation widely spaced observations/platforms give good coverage but make it hard to assess quality through e.g. "buddy checks" Need requirements for accurate large space and time averages (e.g. global, hemispheric and basin annual means with good stability over time) need assessments of data uncertainty for each ECV and obs. type recognise need for multi-variate observations with metadata understand the roles of different types of marine observations Feed back requirements and assessments to GCOS