GISS Surface Temperature of Earth (GISTEMP)

An Extract from The NASA GISTEMP Webpage

Image Courtesy NASA GISS

The Goddard Institute for Space Studies (GISS) Surface Temperature Analysis (GISTEMP) is an estimate of global surface temperature change.

Graphs and tables are updated around the middle of every month using current data files from NOAA GHCN v3 (meteorological stations), ERSST v5 (ocean areas), and SCAR (Antarctic stations), combined as described in our December 2010 publication (Hansen et al. 2010).

These updated files incorporate reports for the previous month and also late reports and corrections for earlier months.

News and Updates

See the GISTEMP News page for a list of announcements and NASA articles related to the GISTEMP analysis.

See the Updates to Analysis page for detailed update information.


Before contacting us, please check if your question about the GISTEMP analysis is already answered in the FAQ.

If the FAQ does not answer your question, please address your inquiry to Dr. Reto Ruedy.

Other researchers participating in the GISTEMP analysis are Avi Persin, Dr. Makiko Sato, and Dr. Ken Lo. This research was initiated by Dr. James E. Hansen, now retired. It is currently led by Dr. Gavin Schmidt.


When referencing the GISTEMP data provided here, please cite both this webpage and also our most recent scholarly publication about the data. In citing the webpage, be sure to include the date of access.

Background of the GISS Analysis

The basic GISS temperature analysis scheme was defined in the late 1970s by James Hansen when a method of estimating global temperature change was needed for comparison with one-dimensional global climate models. The scheme was based on the finding that the correlation of temperature change was reasonably strong for stations separated by up to 1200 km, especially at middle and high latitudes. This fact proved sufficient to obtain useful estimates for global mean temperature changes.

Temperature analyses were carried out prior to 1980, notably those of Murray Mitchell, but most covered only 20-90°N latitudes. Our first published results (Hansen et al. 1981) showed that, contrary to impressions from northern latitudes, global cooling after 1940 was small, and there was net global warming of about 0.4 °C between the 1880s and 1970s.

The early analysis scheme went through a series of enhancements that are listed and illustrated on the History Page.

See the rest of this, in-depth NASA webpage and more starting at:

About GISS

The NASA Goddard Institute for Space Studies (GISS) is a laboratory in the Earth Sciences Division (ESD) of National Aeronautics and Space Administration‘s Goddard Space Flight Center (GSFC). The ESD is part of GSFC’s Sciences and Exploration Directorate.

NASA Goddard Institute for Space Studies
2880 Broadway
New York, NY 10025 USA

General inquiries about the scientific programs at NASA’s Goddard Institute for Space Studies may be directed to the Goddard Space Flight Center Public Affairs office at 1-301-286-8955.

Sea Surface Temperature (SST) | NOAA Resources

Online — Satellite SST is the longest and most mature application of ocean remote sensing. Passive observations are made with infrared (IR) sensors onboard multiple polar-orbiting and geostationary platforms, and microwave sensors onboard polar platforms.

The IR sensors have higher spatial (1-4 km) and temporal (10-15 min, onboard geostationary satellites) resolution, and superior radiometric performance.

However, IR sensors cannot “see through cloud”, thus typically limiting retrievals to ~20% of the global ocean, whereas microwave sensors may see through clouds (except heavily precipitating) and therefore have higher coverage, but have coarser spatial resolution (~20-50 km) and radiometric performance, cannot be used in coastal and marginal ice zone areas, and may be subject to other errors (due to e.g. radio frequency interference, RFI)

NOAA produces several L2 (Level 2) (original swath), L3 (gridded), and L4 (gap-free analysis) SST products in international Group for High-Resolution SST (GHRSST) Data Specifications version 2 (GDS2) and makes them available from NOAA CoastWatch:

Reference web page at NOAA:

ISA Webinar Recording: Temperature Measurement and Control

By Greg McMillan 1 Hour & 35 Minutes+


This educational ISA webinar on control valves was presented by Greg McMillan in conjunction with the ISA Mentor Program.

Greg is an industry consultant, author of numerous process control books, 2010 ISA Life Achievement Award recipient and retired Senior Fellow from Solutia Inc. (now Eastman Chemical).

The ISA Mentor Program enables young professionals to access the wisdom and expertise of seasoned ISA members, and offers veteran ISA professionals the chance to share their wisdom and make a difference in someone’s career.

Click this link to learn more about how you can join the ISA Mentor Program.

This video is freely available online at using the following link:

Radiation thermometry: The measurement problem

Classic article by G. D. (Gene) Nutter from a NASA ARCHIVE

ASTM STP895 Cover
ASTM STP895 Cover (Image credit ASTM International)

This online article is very similar and covers most of the same materials as  “Radiation Thermometry — The Measurement Problem” delivered at a symposium sponsored by ASTM Committee E-20 on Temperature Measurement in cooperation with the National Bureau of Standards, Gaithersburg, MD on May 8, 1984.

This was subsequently published as the first chapter in the volume “Applications of Radiation Thermometry”, ASTM SPECIAL TECHNICAL PUBLICATION 895, J.C. Richmond, National Bureau of Standards and D.P. DeWitt, editors.


Radiation Thermometry—The Measurement Problem
Symposium Paper

January 1985 — STP895  STP38703S
The basic measurement problems of radiation thermometry are discussed, with emphasis on the physical processes giving rise to the emissivity effects observed in real materials. Emissivity is shown to derive from bulk absorptivity properties of the material. Blackbody radiation is produced within an opaque isothermal material, with partial internal reflection occurring at the surface.


Gene Nutter wrote this and many other  technical articles on the subject of radiation thermometry, including another classic , “A High Precision Automatic Optical Pyrometer in Temperatures ITS measurement and Control in Science and Industry, Vol. 4, 519-530, Instrument Society of America (1972).

Description: “An overview of the theory and techniques of radiometric thermometry is presented. The characteristics of thermal radiators (targets) are discussed along with surface roughness and oxidation effects, fresnel reflection and subsurface effects in dielectrics.

“The effects of the optical medium between the radiating target and the radiation thermometer are characterized including atmospheric effects, ambient temperature and dust environment effects and the influence of measurement windows.

“The optical and photodetection components of radiation thermometers are described and techniques for the correction of emissivity effects are addressed.”

NASA Info:Link to article:

Publication date 1988-03-01
Collection NASA_NTRS_Archive; additional_collections
Language English
Identifier NASA_NTRS_Archive_19880014512
Identifier-ark ark:/13960/t9h46mr2v
Ocr ABBYY FineReader 11.0
Pages 61

Ed Note (from the book jacket of the 1988 book “Theory and Practice of Radiation Thermometry”,  Edited by D.P. Dewitt and Gene D. Nutter, John Wiley & Sons, Inc.): “Gene D. Nutter is (was)  a senior staff member of the Instrumentation Center, College of Engineering, University of Wisconsin-Madison. He received his MS in Physics from  University of Nebraska and had been earlier associated with the National Bureau of Standards and Atomics International.”

Chapter 5 in the above referenced text is linked below below. a classic book on the theory & practices of radiation thermometry published in 1998. It was recently found on and at the following links: FOR ABOUT $349.

AND for between $353 and $453 on ebay at:


Earth as a Greenhouse

If you have problems understanding the science side of the (so called*) debate on Global Warming, consider Earth as a greenhouse**.

Whoops! It actually is!

Earth's global energy budget (PDF)
References: Trenberth, K. E., J. T. Fasullo, and J. Kiehl, 2009: Earth’s global energy budget (PDF). Bull. Amer. Meteor. Soc., 90, No. 3, 311-324,

Gases in the atmosphere that trap heat in the atmosphere are called greenhouse gases.

The USA’s Environmental Protection has an interesting webpage at that details the types of gases and their relative impact on Global Warming.

The most common and pervasive of these is, of course, Carbon Dioxide, known by its chemical designation CO2 and or the variation on that that is used by non-science types, CO2.

View the Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990–2015 (published 2017), developed by the U.S. Government to meet U.S. commitments under the United Nations Framework Convention on Climate Change (UNFCCC).

Visit the public comments page to learn more about comments EPA received on the public review draft of the 1990-2015 GHG Inventory report.

Prior year versions of the GHG Inventory are available on the U.S. Greenhouse Gas Inventory Archive page.

But, possibly unknown to the Administrator of EPA, the USA’s Department of Energy (DOE) has been working in the same area but with the objective of not only understanding sources and sinks of greenhouse gases like Carbon Dioxide, but with and eye to doing something about reducing it.

Here’s are some key links and a chart from the DOE website, Let’s hope that they don’t get “modified” in the pursuit of “political nonscience” – if this link vanishes, you’ll know – but in the interest of transparency we have copied the image and published it here.

The largest contributor to these emissions is from electricity production (73 percent).(click to learn more about sources and sinks)

The diagram depicting the stationary anthropogenic CO2 emissions by major industry is (from a DOE web page


Diagram depicting the stationary anthropogenic CO2 emissions by major industry.
The largest contributor to these emissions is from electricity production (73 percent).
(click to enlarge)

 Myth: Carbon dioxide comes only from anthropogenic sources, especially from the burning of fossil fuels.
Reality: Carbon dioxide comes from both natural and anthropogenic sources; natural sources are predominant.

Are the additional emissions of anthropogenic CO2 to the atmosphere impacting the climate and environment?

To learn more, search the web! The search engine that doesn’t track you and use your preferences in their business is and their search results for a search on “greenhouse effect” is at:


*In a real debate both sides are assumed to be sincere. Most of the Global Warming critics deny proven science and few, if any, can provide reproducible, alternate scientific basis for their arguments. They just argue, the last bastion of obstructionism.

Thus, the deniers “side” is widely suspected of being not only insincere, but also biased against the facts in order to avoid taking needed action and denying only out of some other agenda than saving mankind’s future.

Recently some politicians in the USA have grudgingly agreed that the Earth is warming but continue the denial of man’s influence and the need to reduce greenhouse gases. Thus inaction persists in the USA and other countries with deniers in power. 

However the rest of the civilized world has better science educated populous and elected representatives and they are making an effort to help slow the effects of greenhouse gases.



There are many specialized glossaries that cover the terms describing the unique details of temperature and moisture sensors and their uses and this page represents an attempt to index most of them and related topics, such as Meteorology, in one place.






Many online articles about radiation thermometry and its uses (infrared thermometers, radiation pyrometers) exist including technology articles, PowerPoint slide presentations and .pdf downloads, but they seem to be vanishing as more and more “big businesses” take over these specialized sensors.But few are aimed at being useful glossaries or definition of terms.

There are some exceptions and some well-crafted pieces that have been online for a while and can be found in semi-hidden corners of the Web.

Thermal Radiation Thermometers: temperature_measurement_radiation_thermometers

Thermal Imaging:  (Glossary of Basic Thermography Terms) .


American Meteorological Society’s (AMS) Glossary of Meteorology

The electronic version of the second edition of the AMS Glossary of Meteorology is a living document and meant to be periodically updated as terms in the field evolve. To that end, AMS has established a Chief Editor for the Glossary who is responsible for updating/revising existing terms and adding new terms. Learn more about the Glossary and current Editorial Board.

For recommendations on correctly citing and referencing the Glossary of Meteorology, please see the Glossary entry for Citation.

If you have any feedback or editing suggestions to the content in this Glossary, please contact the Chief Editor.

Glossary – NOAA’s National Weather Service

This glossary contains information on more than 2000 terms, phrases and abbreviations used by the NWS. Many of these terms and abbreviations are used by NWS forecasters to communicate between each other and have been in use for many years and before many NWS products were directly available to the public.

Glossary of Weather, Climate and Ocean 2nd Edition

ISBN: 9781935704799

Intended for educators, students and the public and inspired by increasingly interest in the atmosphere, ocean and our changing climate, this glossary provides an understandable, up-to-date reference for terms frequently used in discussions or descriptions of meteorological, oceanographic and climatological phenomena. In addition, the glossary includes definitions of related hydrologic terms.

Clearly this page is a work in progress, and it may be expanded in time. Priority will be according to the response it garners.

Thermistor Glossary and Terminology

Thermistor Terminology

A glossary slightly modified from that given in a US government publication: MIL-PRF-23648D.
Note that the term being described is in bold typeface. (Note also, that this replaces a part of the information page here on thermistors – it has been slightly edited from the original)

A thermistor is a thermally sensitive resistor that exhibits a change in electrical resistance with a change in its temperature. The resistance is measured by passing a small, measured direct current (dc) through it and measuring the voltage drop produced.

The standard reference temperature is the thermistor body temperature at which nominal zero-power resistance is specified, usually 25 °C.

The zero-power resistance is the dc resistance value of a thermistor measured at a specified temperature with a power dissipation by the thermistor low enough that any further decrease in power will result in not more than 0.1 percent (or 1/10 of the specified measurement tolerance, whichever is smaller) change in resistance.

The resistance ratio characteristic identifies the ratio of the zero-power resistance of a thermistor measured at 25 °C to that resistance measured at 125 °C.

The zero-power temperature coefficient of resistance is the ratio at a specified temperature (T), of the rate of change of zero-power resistance with temperature to the zero-power resistance of the thermistor.

A NTC thermistor is one in which the zero-power resistance decreases with an increase in temperature.

A PTC thermistor is one in which the zero-power resistance increases with an increase in temperature.

The maximum operating temperature is the maximum body temperature at which the thermistor will operate for an extended period of time with acceptable stability of its characteristics. This temperature is the result of internal or external heating, or both, and should not exceed the maximum value specified.
The maximum power rating of a thermistor is the maximum power which a thermistor will dissipate for an extended period of time with acceptable stability of its characteristics.

The dissipation constant is the ratio, (in milliwatts per degree C) at a specified ambient temperature, of a change in power dissipation in a thermistor to the resultant body temperature change.

The thermal time constant of a thermistor is the time required for a thermistor to change 63.2 percent of the total difference between its initial and final body temperature when subjected to a step function

The resistance-temperature characteristic of a thermistor is the relationship between the zero-power resistance of a thermistor and its body temperature.

The temperature-wattage characteristic of a thermistor is the relationship at a specified ambient temperature between the thermistor temperature and the applied steady state wattage.

The current-time characteristic of a thermistor is the relationship at a specified ambient temperature between the current through a thermistor and time, upon application or interruption of voltage to it.

The stability of a thermistor is the ability of a thermistor to retain specified characteristics after being subjected to designated environmental or electrical test conditions.

Thermography Service Providers

Below is a list of some Thermal Imaging Services or Directories where more lists can be found. It is not complete, we know.

Sorry if you were left out. If you should be listed or know of others who should be listed or if you want to improve your organization’s listing, let us know, please.

Note that the training organizations are listed on a separate page. Some of them provide classified ads for used equipment as do some of the service providers below.

Also, some of the training companies do other things, like practice thermography and run information exchange/training meetings at nice places in the Fall and Winter, like Orlando, New Orleans and Las Vegas.

Tell your new product and application stories at The Temperature Directories website: or feedback to us and we’ll consider adding it here with your byline!


  1. AITscan(USA)
    A unique inspection service that has developed a high-tech approach to aerial infrared thermographic scans for large, flat-roofed buildings as well as locating Stormwater pollution sources and more. A most visually and technically rewarding website.
  2. Allis Engineering San Juan Capistrano, CA
  3. Chemical & Infrared INSPECTIONS, LLC (USA)
    Professional Services Assisting Industrial, Commercial and Residential Customers locate potential problems through Infrared Thermography and Structural Drug Detection
  4. Colbert Infrared Services, Inc. (USA)
    All of their Infrared Thermographers have completed the ASNT (American society of Non-destructive Testing) requirements for certified Thermographers, are members of the Professional Thermographers Association, and have had extensive training as Certified Thermal Trend Professional Solution Providers. The latter is their own software that they developed, sell and support for data collection, and fault-finding.
  5. Emerson Process Management/CSI (USA)
    Reliability Based Maintenance: vibration, tribology, oil lab services, motor monitoring, ir thermography, laser alignment, dynamic balancing, and RBM Services.
  6. The Infrared Training Center
    Provides a directory of IR service provider organizations (and much more) on their web site.
  7. Infrared Inspection’s   Lists of Service Providers:
  8. InfraredPredictive Surveys, Inc. (USA)
    A Maryland Corporation is “The Total Inspection and Survey Service for Architects, Owners and Industry”, that performs infrared inspections of electrical systems, ovens, bearings, gears, condensers, heat exchangers, belt drives, chain drives, refractory insulation, valves, hydraulic systems, pumps, tanks and electrical equipment and more.
  9. Infrared Services, Inc.(USA)
    A Colorado Corporation that has been doing electrical, distribution, power system, uninterrupted power systems, mechanical systems, rotating equipment, roof moisture, energy audits, glycol snow melt systems, plumbing leak detection and other nondestructive surveys for over 9 years.
  10. IRInfo’s Thermal Imaging Service List for Canada
  11. IRInfo’s Thermal Imaging Service List for Israel
  12. IRInfo’s Thermal Imaging Service List for Mexico
  13. IRInfo’s Thermal Imaging Service List for Trinidad
  14. IRInfo’s Thermal Imaging Service List for The USA-by State
  15. Jersey Infrared Consultants(USA)
    Focused on process and predictive maintenance, JerseyIR is known throughout the USA for its expertise in petroleum thermal cracking and petrochemical thermal reformer furnaces-Headquartered in Burlington New Jersey, near Philadelphia PA.
  16. Kleinfeld Technical Services, Inc. . Bronx, New York (USA).
    A unique company with IR Thermography, heat transfer analysis, process engineering and FEA consulting services run by Jack Kleinfeld, P.E., a graduate chemical engineer.
  17. Maintenance Reliability Group, Another unique organization, one aimed at the big picture of reliability in maintenance operations-with a strong thermography component. Run by Rich Wurzbach in south central Pennsylvania.
  18. PIRS – Pregowski Infrared Services (Poland)
    Twój przewodnik do sukcesu w zastosowaniu detekcji w podczerwieni (Your guide to success in application of infrared detection).
  19. Si Termografia Infraroja . Bueneos Aires, (Argentina),
    Services, consulting and products for infrared thermal imaging from Sr. Andrés E. Rozlosnik.
  20. Sierra Pacific Innovations(USA)
    SPI infrared thermography services thermal imaging infrared inspections. They have, according to their web site, the largest selection on the internet of new, demo, and previously owned imagers. 251 Waterton Lakes Avenue, Las Vegas, NV 89148.
  21. Stockton Infrared Thermographic Services, Inc.(USA)
    A major service company located in North Carolina. Stockton is dedicated to providing a wide range of quality infrared thermographic services to their clients. They do not manufacture or represent products of any kind and do not provide any services other than infrared. Their site features images, videos and a great deal of information on applications. Stockton is divided into four seperate divisions and provide the following services:
  • The Aerial Infrared Thermography at Stockton is performed by its AITscan Division: Stormwater and other unplanned and illicit water discharges into Waterways and Lakes can be found more quickly at much lower cost than shoeleather surveys with AITscan’s PollutionFindIR™ Services
  • Aerial Roof Moisture Surveying with RoofMoistureFindIR™ Services
  • Steam System Surveying with SteamLeakFinderIR™
  • Hot Water System Surveying with HotwaterLeakFinderIR™
  • Environmental Impact and Animal Counts with *AnimalFindIR Services
  • ELECTRICAL/MECHANICAL PREDICTIVE MAINTENANCE DIVISION * Electrical Switchgear IR/PM * Mechanical Systems IR/PM * Steam System Infrared *
  • BUILDING QUALITY ASSURANCE DIVISION * Building Structural Integrity * Heat Loss Analysis *
  • PROCESS IMPROVEMENT/R&D DIVISION * Process Improvement * On-line feasibility studies * Unbiased IR camera selection consulting * Pulp & Paper Industry Infrared * Infrared Research & Development
  • Snell Infrared(USA & Canada)
    A major thermal imaging service and training company
  • Snell Infrared’s List of Service Providers
  • Thermal Inspection Services,Allentown, PA(USA)
    Electrical, Mechanical, Roofing, Building Energy Audits, Production Process Evaluations
  • Therma Scan,(USA)
    An experienced industrial team of thermographers from the Northern Penninsula of Michigan (The U. P.)serving industry and commerce.
  • Thermal Vision (Ireland)
    State of art thermography service based near Dublin. Providing quality thermal imaging solutions worldwide.

About The Global Climate Observing System (GCOS) & More!

GCOS-aboutOnline — GCOS, the Global Climate Observing System, is a joint undertaking of:

  • The World Meteorological Organization (WMO),
  • The Intergovernmental Oceanographic Commission (IOC) of the United Nations Educational Scientific and Cultural Organization (UNESCO),
  • The United Nations Environment Programme (UNEP) and
  • The International Council for Science (ICSU).


Its goal is to provide comprehensive information on the total climate system, involving a multidisciplinary range of physical, chemical and biological properties, and atmospheric, oceanic, hydrological, cryospheric and terrestrial processes.

It is built on the WMO Integrated Global Observing System (WIGOS), the IOC-WMO-UNEP-ICSU Global Ocean Observing System (GOOS), the UN Food and Agriculture Organization (FAO)-UNEP-UNESCO-ICSU Global Terrestrial Observing System (GTOS) and a number of other domain-based and cross-domain research and operational observing systems.

It includes both in situ and remote sensing components, with its space based components coordinated by the Committee on Earth Observation Satellites (CEOS) and the Coordination Group for Meteorological Satellites (CGMS).

GCOS is intended to meet the full range of national and international requirements for climate and climate-related observations.

As a system of climate-relevant observing systems, it constitutes, in aggregate, the climate observing component of the Global Earth Observation System of Systems (GEOSS)

The Global Observing System is an extremely complex undertaking, and perhaps one of the most ambitious and successful instances of international collaboration of the last 100 years. It consists of a multitude of individual observing systems owned and operated by a plethora of national and international agencies with different funding lines, allegiances, overall priorities and management processes.

Learn more at: ,  and


Understanding Radiation Thermometry Parts I & II

From NASA Technical Reports Server (NTRS)

From NASA Article
From NASA Article

In 2015, Timothy K. Risch of NASA developed two technical articles that are available on the NASA Technical Reports Server (NTRS).

Both articles may be freely downloaded from NTRS in various formats, as long as the NASA Server maintains their presence.

As far as we know these are royalty free and the only stipulation that NASA usually requires is an attribution. These are below in the form of links to the article on the NASA web site.

The articles are entitled:

Understanding Radiation Thermometry. Part I, 71 pages, publication date 2015-07-08, and Understanding Radiation Thermometry. Part II, 111 pages, same publication date.

We have reviewed these documents and find them to be an excellent summary of this temperature measurement method and have archived them on our site in two formats, mobi, suitable for reading on an E-reader and in Adobe pdf format.

Part 1 provides and Overview, Nomenclature, a bit about what temperature is and the history of measurement methods and delves into the physics underlying Radiation Thermometry.

Part II covers practical radiation thermometers, some detail on measurement techniques and calibration and a brief reference list.

These files are linked below many be freely downloaded as long as we maintain this website.

The NASA description for both article reads as follows:

This document is a two-part course on the theory and practice of radiation thermometry.

Radiation thermometry is the technique for determining the temperature of a surface or a volume by measuring the electromagnetic radiation it emits.

This course covers the theory and practice of radiative thermometry and emphasizes the modern application of the field using commercially available electronic detectors and optical components.

The course covers the historical development of the field, the fundamental physics of radiative surfaces, along with modern measurement methods and equipment.
NASA Technical Reports Server (NTRS) 20150021314 Understanding Radiation Thermometry. Part I NASA Technical Reports Server (NTRS) Free Download & Streaming Internet Archive

Understanding Radiation Thermometry – Part I pdf Format Timothy K. Risch NASA Armstrong Flight Research Center July 8, 2015

NASA Technical Reports Server (NTRS) 20150021315 Understanding Radiation Thermometry. Part II NASA Technical Reports Server (NTRS) Free Download & Streaming Internet Archive

Understanding Radiation Thermometry – Part II pdf Format Timothy K. Risch NASA Armstrong Flight Research Center July 8, 2015

Sources on the NASA Technical Reports Server: