NOAA's National Climatic Data Center
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Dr. Thorne completed his PhD in Climate Change Detection and Attribution in 2001 from the Climatic Research Unit in the University of East Anglia. He then worked at the Met Office Hadley Centre in the UK until 2010 within the Climate Monitoring and Attribution group. Initial work concentrated upon tropospheric temperature records. Together with colleagues, he created a radiosonde-based temperature dataset, automated the procedure, and benchmarked it against realistic test cases. This led to a conclusion that radiosonde temperatures were not adequate enough to conclusively inform on the debate about an apparent temperature trend discrepancy between the surface and the troposphere. He also contributed significantly to the CCSP report on this subject including lead-authorship on two chapters. Most recently he led, together with colleagues from NOAA and Reading University, a major review of the issue.
In the past several years Dr. Thorne's focus has turned to creating climate data records from the land surface network. He supervised a PhD project, which yielded a quality, controlled, homogenized surface humidity product at monthly resolution and contributed to subsequent analyses thereof. This analysis utilized the synoptic report resolution Integrated Surface Dataset from NCDC. Subsequent work has been focused on creating a quality-controlled version of this database for solely the long-running stations, which utilize an automated procedure with a view to subsequently undertaking homogenization efforts at the base reporting observation level. Whether this is even possible is an open question being pursued in collaboration with colleagues in the Met Office Hadley Centre and University of New South Wales Climate Change Research Centre.
Dr. Thorne has published on reanalyzes and has sat on a joint Global Climate Observing System / World Climate Research Program working group on observations for reanalyzes. He has also published on radiosonde humidity records and satellite Microwave Sounding Unit datasets.
For the last six years Dr. Thorne has been chair of a Working Group under the Auspices of the Global Climate Observing System whose role is to make the GCOS Reference Upper Air Network a reality. Since September 2010 he has chaired the steering committee of the International Surface Temperatures Initiative.
For the past three years Dr. Thorne has been an editor of the global chapter of the annual State of the Climate report. Dr. Thorne also contributed to two chapters of the IPCC 4th Assessment Working Group 1 report. He is a lead author for Working Group 1 of the IPCC 5th Assessment Report.
Dr. Thorne joined CICS-NC as a senior scientist and research associate professor in May 2010.
Significant progress has been made on creation of a new surface temperature databank resource with over 40 contributions from the international community that will yield an initial release consisting of the order of 40,000 stations – a marked improvement over GHCN. A substantial reassessment of US surface temperature records reinforced our understanding of this record and pointed to an asymmetrical error with far greater probability that we underestimate than overestimate the real trend. The GCOS Reference Upper Air Network continues to grow and we have received applications from several new sites.
In situ climate records represent a substantial challenge both historically and into the future. These measurements were never made in a metrologically traceable fashion and change has been ubiquitous. These projects aim to address both the backward looking problem and propose solutions moving forwards.
The International Surface Temperature Initiative aims to improve our fundamental understanding of historical land surface records through a renewed effort to gain better ‘raw’ data holdings and improved provenance thereof, look at the homogenization problem anew and undertake benchmarking (software testing) in a rigorous fashion.
The GCOS Reference Upper Air Network aims to create a network of global reference quality measurements with robust uncertainty estimates derived through an unbroken chain to absolute standards. Within year representation was made to GCOS to instigate a similar global surface network along the lines of USCRN. Within a system of systems approach such networks form the top tier and will be instrumental in insuring the quality of the future climate record for future generations of researchers.
Significant advances have been made in the efforts to create a first version release of a monthly land surface temperature databank. Over 40 data sources have been accrued from national and international partners. Work has then been undertaken by CICS and NCDC staff to create a merging procedure that is automatic, modular, and tunable. Efforts are ongoing in this regard and a first release is envisaged in summer 2012. This release is likely to consist of the order 40,000 unique stations. Figure 1 shows the map of station availability in the 40 sources prior to attempting to merge.
Figure 1. Map of station coverage as at 1/13/12 in the databank. Source: Jared Rennie
Significant efforts have also accrued on other aspects of the surface temperature initiative. An example of benchmarking approaches has been published in JGR considering the US land surface data record USHCN. The use of benchmarks, and an ensemble of plausible realizations of the pairwise homogenization algorithm yielded additional insights into the likely uncertainties in this record. The algorithm was shown to be reasonable but have a propensity to under-estimate the trend adjustment required in the presence of an overall systematically biased input data stream with a propensity for breaks of one sign. This is similar to known facets of the US surface raw data yielding a conclusion that we are far more likely to be underestimating than overestimating CONUS warming trends.
Efforts continue to build up the GCOS Reference Upper Air Network. Regulatory materials have been prepared and vetted. Data has started flowing for the first product – radiosonde profiles – through NOAA NCDC. Significant progress has been made towards bringing additional measurements into the data stream including lidars, radiometers and GPS precipitable water. Three new sites have applied or are in the process of applying to join the network.
Work has continued on the IPCC WG1 AR5 drafting process. The First Order Draft was prepared and submitted to review. These reviews art now in the process of being considered. Authorship on the climate chapter team for the National Climate Assessment has started.
Williams, C. N., M. J. Menne, and P. W. Thorne, Benchmarking the performance of pairwise homogenization of surface temperatures in the United States. J. Geophys. Res., 117, D05116, doi:10.1029/2011JD016761
Thorne, P. W., K. M. Willett et al. Guiding the Creation of a Comprehensive Surface Temperature Resource for 21st Century Climate Science. Bull. Am. Met. Soc., doi: 10.1175/2011BAMS3124.1
Santer, B. D., C.A. Mears, C. Doutriaux, P.M. Caldwell, P.J. Gleckler, T.M.L. Wigley, S. Solomon, N. Gillett, D.P. Ivanova, T.R. Karl, J.R. Lanzante, G.A. Meehl, P.A. Stott, K.E. Taylor, P. Thorne, M.F. Wehner, and F.J. Wentz. Separating Signal and Noise in Atmospheric Temperature Changes: The Importance of Timescale. J. Geophys. Res., doi:10.1029/2011JD016263,
Peterson, T. C., K. M. Willett et al. Observed changes in surface atmospheric energy over land. Geophys. Res. Lett., 38: L16707, doi:10.1029/2011GL048442
Thorne, P. W., et al. A quantification of uncertainties in historical tropical tropospheric temperature trends from radiosondes. J. Geophys. Res. - Atmos., 116, D12116, doi:10.1029/2010JD015487.
Seidel, D. J., N. P. Gillett et al. Stratospheric temperature trends: Our evolving understanding. WIRES: Climate Change, 2(4): 592-616 DOI: 10.1002/wcc.125
Blunden, J., D. S. Arndt et al. State of the climate in 2010. Bull. Amer. Met. Soc., 92(6), S1-S266
Dai, A. G., J. H. Wang, et al. A New Approach to Homogenize Daily Radiosonde Humidity Data. J. Clim., 24(4): 965-991.
Mears, C. A., F. J. Wentz, et al. Assessing uncertainty in estimates of atmospheric temperature changes from MSU and AMSU using a Monte-Carlo estimation technique. J. Geophys. Res. - Atmos., 116, D08112 doi:10.1029/2010JD014954.