2.1.5 Climate of the past century
SSTs around Cleveland Bay have, in keeping with the rest of the
GBR (Lough 1999), significantly warmed over the past century (Figure
3). Annual average SSTs are 0.6oC warmer in the last 30
years of the 20th century compared with the first 30
years of the century. As has been occurring in Queensland (Lough,
1997), air temperatures in Townsville have also been rising (Figure
4). Annual average temperatures for the most recent 20 years of
record (1979-98) are 0.5oC warmer than in the first 20
years of record (1941-60). Warming has been slightly greater for
minimum (nighttime) temperatures which have increased by
0.9oC over the same time period. Rainfall in Townsville
is characterized by considerable inter-annual and inter-decadal
variability (eg wetter 1950s and 1970s) and shows (similar to
Queensland, see Lough, 1991, 1997) no significant trend over the
past century towards wetter or drier conditions (Figure 5).
Figure 2.3
Average annual (black), maximum (red) and minimum (blue) sea-surface
temperatures at 19.5oS, 147.5oE from
1903-2000. Dashed lines are linear trend lines.
Figure 2.4 Townsville
AMO annual average (black line), annual maximum (red line) and
annual minimum (blue line) air temperatures, 1941-1998. Dashed lines
are linear trend lines.
Figure 2.5
Townsville total summer (red bar) and winter (blue bar) rainfall,
1895-1999. Total height of bars give annual total rainfall for water
year (October-September). |