// lecture 02

Question 1

15 of the warmest years occurred in the last

Answer 1

17 yrs.

Question 2

a running means averages

Answer 2

N things together, then steps forward on unit and repeats.

Question 3

northern hemisphere has warmed

Answer 3

more (1 C vs 0.8 C globally).

Question 4

southern hemisphere has warmed

Answer 4

more steadily though.

Question 5

cooling from

Answer 5

1940-1975 only in the northern hemisphere.

Question 6

thermometers

Answer 6

ancient Greeks knew that gases/liquids expand when heated.

Question 7

Galileo

Answer 7

played around with thermometer type devices (1592).

Question 8

Ferdinand II de Medici

Answer 8

invented the sealed glass thermometer (more accurate) around 1650. measured temps. within artificial incubators to hatch chicks. established the first international network of weather stations, with 8 stations in Italy, also Warsaw, Paris, Innsbruck, Osnabruck.

Question 9

Daniel Gabriel Fahrenheit

Answer 9

invented his scale in 1724. also invented the mercury thermometer (1714). scaled based on three points: freezing points (32), cold temp. of an ice/salt/water mixture (0), and underarm temp. (96). later defined to just depend on 32 and 212 degrees.

Question 10

Anders Celsius

Answer 10

1742; based on 0 for boiling and 100 for freezing. reversed to make 0 freezing and 100 boiling by Linnaeus in 1745.

Question 11

Meteorological Society of Mannheim

Answer 11

37 stations in Europe, 2 in North America. very rigorous procedures for making measurements, calibrating instruments.

Question 12

invention of the telegraph allowed for

Answer 12

quick construction of weather maps by 1850.

Question 13

first international meteorological conference (august 1853)

Answer 13

US navy lieutenant Matthew Maury developed standard procedure for meteorological observations on ships.

Question 14

Stevenson screen

Answer 14

invented by Robert Stevenson’s dad Thomas (1818-1887). thermometer between 1.25-2 m above ground. white colored to reflect away direct sunlight. slats to ensure fresh air circulation. needs water supply for wet bulb temp. difference between wet and dry gives humidity.

Question 15

NASA keeps track of land-only measurements

Answer 15

separately. warming in the land station data record is larger than in the full record (1.5 C vs 1 C).

Question 16

“bucket” temperature

Answer 16

older style subject to some cooling by evaporation.

Question 17

starting around WWII, many measurements taken from

Answer 17

condenser intake pipe instead of from buckets.

Question 18

good enough global coverage started around

Answer 18

1880-1890.

Question 19

groups like NASA, NOAA, CRU, have two steps:

Answer 19

1) remove inhomogeneities in individual stations due to changes in observing practices, station environment, or other non-meteorological factors.
2) they also have procedures for combining fragmented record. well documented.

Question 20

missing data

Answer 20

CRU and NOAA don’t include the arctice ocean where there’s no data. NASA fills these points with the nearest station. others, excluding NASA, aren’t including the rapidly warming area.

Question 21

pitfalls of temperature measurements:

Answer 21

incomplete spatial sampling; short and “gappy” records; instrument changes; changes in station site, which is sometimes undocumented; changes in exposure of station site; changes in observing protocol; transcription errors; invalid data (faulty instruments, unreliable observers); and “urban heat” island effect.

Question 22

virtue of the temperature measurements:

Answer 22

redundancy, many different stations, three different data sets (land, ocean, upper air), and multiple analysis methods by different groups.

• random errors tend to average out.
• systematic errors can be removed by calibration.
• estimated uncertainty with global temp. measurements: currently 0.1 C.

Question 23

Berkeley Earth Surface Temperature (BEST) group

Answer 23

started by Richard Muller. had funding from various sources, including the Koch brothers. found 3 things.

Question 24

BEST discovery #1

Answer 24

found that the urban heat island effect is locally large, but does not contribute significantly to the average local temp.

Question 25

BEST discovery #2

Answer 25

about 1/3 of temp. sites reported cooling over the past 70 years. 2/3 of the sites show warming.

Question 26

BEST discovery #3

Answer 26

the El Nino-Southern Oscillation (ENSO) is generally thought to be the main reason for inter-annual warming or cooling, but they found that the global temp. correlate more closely with the state of the Atlantic Multidecadal Oscillation (AMO) index; which is a measure of sea surface temp. in the North Atlantic.

Question 27

how to define an AMO by:

Answer 27

taking the SST over the N. Atlantic, remove the linear trend or some other smooth variation. the leftover is the AMO. high in 1940 and 2000, low in 1970-1990.

Question 28

remote temperature sensing

Answer 28

the microwave sounding unit (MSU) since 1979. works like infrared thermometer, except microwave. multiple wavelength channels give temperatures at different heights. global coverage twice daily.

Question 29

radiosondes

Answer 29

weather balloons; since 1946.

Question 30

In 2001…

Answer 30

we thought that the surface warmed much faster than the upper atmosphere. yet, both are supposed to heat up together.

Question 31

prior to 2001…

Answer 31

global warming skeptics, Spencer and Christy, and the UAH team were the sold producers of the MSU satellite estimates.

Question 32

Remote sensing systems (RSS)

Answer 32

also now produce a satellite temperature record. offers independent estimates of trends and shows much significant warming. Celeste Johanson identified an error in the algorithm. Show substantial upper air warming.

Question 33

More than ____ of scientists are convinced that ______

Answer 33

97%; the global is warming.