AGW – Anthropogenic Global Warming (ie… man-made changes to our climate)
AR4 – IPCC’s Fourth Assessment Report on global warming [link] (UN)
BOM – Bureau of Meteorology (Australian)
CCSP – The Climate Change Science Program was the U.S. government’s program responsible for coordinating and integrating research on global change and climate change across thirteen federal agencies from February 2002 to June 2009.
CAGW – Catastrophic Anthropogenic Global Warming. (ie. caused by us and really bad news).
CCTP – United States Climate Change Technology Program or CCTP is a multi-agency planning and coordination entity.
cld – cloud cover (percentage)
CO2 – Carbon Dioxide
CRU – Climate Research Unit (Lately it often refers to the East Anglia CRU, but could refer to others).
DTR – diurnal temperature range (degrees Celsius)
FAR – IPCC First Assessment Report: 1990 [link]
FOI (FOIA) – Freedom of Information (Act) — laws governing public data access
FRS – frost day frequency (days)
GCM – Global Climate Model
GISS – (US) Goddard Institute of Space Studies – a NASA unit
Gust – A sudden increase in wind speed of 9 knots or more lasting less than 20 seconds.
HADcrut – Combined land sea temperature database from the (UK) Hadley Climate Research Center
Hadley – Hadley Centre for Climate Prediction and Research at Exeter, England. (UK)
hPa – A hecto Pascal. A unit of pressure (identical to a millibar).
Inversion – A point where the air begins to get warmer with altitude (usually things get colder as you rise off the Earth).
IPCC – (UN) Intergovernmental Panel on Climate Change [Link]
Lapse Rate – There are two different types of lapse rates. The normal or environmental lapse rate is the rate that stationary air cools as a thermometer rises up through it (about 6.5 degrees C per Km). The adiabatic lapse rate refers to air that is itself rising up through the atmosphere. Because air expands as the pressure falls, even large “parcels” of air will cool as they rise. Rising dry air loses heat faster (10 degrees per km) than rising humid air (6 degrees per km). [Enc Brittanica, UWSP]
MSU – Microwave Sounding Unit (ie a satellite that send out microwaves)
NASA – National Aeronautic and Space Administration
NCDC – National Climate Data Center (archives weather reports) (US)
NH – Northern Hemisphere
NOAA – National Oceanic and Atmospheric Administration (US)
PCA – Principal component analysis – a statistical analysis technique
pre – precipitation (millimetres)
Radiosonde – Weather Balloons that measure pressure, temperature, humidity, and winds as they rise to 30 km or higher. (Also known as a rawinsonde.)
rhm relative humidity percentage
Rocketsonde – Sounding instrument lofted by rocket (ie, like a weather balloon but it rises faster!)
RSS – Remote Sensing Systems [Link]
RSS – Remote Sensing Systems – US Corporation involved in satellite measurementation
SAR – IPCC Second Assessment Report: Climate Change 1995 [Link]
SH – Southern Hemisphere
SLP – Sea Level Pressure
Sounding – An instrument probe (of the atmosphere)
ssh – sunshine duration (hours)
SST – Sea Surface Temperature
Stratosphere – The layer of air above the Tropopause (roughly 15km – 50 km up)
Surface Temp – Temperature at about 2m above the earth’s surface [IPCC link]
TAR – IPCC Third Assessment Report
tmp – daily mean temperature (degrees Celsius)
Troposphere – The layer of air roughly 10-12 km thick between ground and the Tropopause (it’s where all the clouds hang out.)
Tropopause – The point in the upper atmosphere where the lapse rate levels out
UAH – University of Alabama at Huntsville, USA
UHI – Urban Heat Island (heat induced by civilization)
vap – vapour pressure (hecta-Pascals)
wet – wet day frequency (days)
WG-1, WG-2, WG-3 – IPCC working groups [link]
WMO – World Meteorological Organization, another UN organization
wnd – wind speed metres per second
Thanks to Rob, Bob and Barry for help with these.
Others we may have missed might be found at: Climate Audit’s Glossary
AFAIK – As Far As I Know
BTW – By The Way
DIY – Do It Yourself
GIGO – Garbage In Garbage Out
FUBAR – Fouled Up Beyond All Recognition
FWIW – For What It’s Worth
FYI – For Your Information
IME – In My Experience
IMHO – In My Humble Opinion
IOW – In Other Words
KISS – Keep It Simple, Stupid
LMAO – Laughing My @ $$ Off
LOL – Laughing Out Loud
OT – Off Topic
OTOH – On The Other Hand
ROFL – Rolling On Floor Laughing
ROFLMAO – Rolling On Floor, Laughing My A$$ Off
ROTF – Rolling On The Floor (laughing is implied)
There are more web acronyms here.