climate change and extreme precipitation

Climate Change &

Extreme Precipitation

Jessica RennellsNOAA, Northeast Regional Climate Center at Cornell

University

What is Climate Change?The Earth is warming because of

increased greenhouse gases.

Global Average Annual Temperature Anomaly (oF)From meteorological stations 1880-2005

Hansen et al. (2001) J. Geophysical Res. Vol 106, p. 23,947-23,963Data from http://www.giss.nasa.gov/data/update/gistemp/

-1.0

-0.5

0.0

0.5

1.0

1.5

1880 1900 1920 1940 1960 1980 2000

Te

mp

era

ture

An

om

oly

(o F)

Year

1995-2004 vs. 1940-1980

-3.6 -1.8-2.7 -0.9 3.62.7 1.80.90.0

F

189518961897189818991900190119021903190419051906190719081909191019111912191319141915191619171918191919201921192219231924192519261927192819291930193119321933193419351936193719381939194019411942194319441945194619471948194919501951195219531954195519561957195819591960196119621963196419651966196719681969197019711972197319741975197619771978197919801981198219831984198519861987198819891990199119921993199419951996199719981999200020012002200320042005200620072008200920102011201243

44

45

46

47

48

49

50

51

Year

Avera

ge A

nnual Tem

pera

ture

°F

Coldest year on record - 1917

Hottest year on record - 2012

Average Annual Temperature in Northeast

1895 - 2012

Hudson Valley Climate Division Average Annual Temperature

1895-2012

1895 1902 1909 1916 1923 1930 1937 1944 1951 1958 1965 1972 1979 1986 1993 2000 200744

45

46

47

48

49

50

51

Year

Tem

pera

ture

°F

Spatial Variation of Days with Snow on Ground 1970-2000

Winter/Spring Center of Volume Dates

Sea level rise

New York State Average Annual Temperature

1895190119071913191919251931193719431949195519611967197319791985199119972003200930

34

38

42

46

50

54

58

Year

Annual P

recip

itati

on (

inches)

Average Annual Precipitation in the Northeast1895-2012

Hudson Valley Climate DivisionAverage Annual Precipitation

1895-2012

1895 1902 1909 1916 1923 1930 1937 1944 1951 1958 1965 1972 1979 1986 1993 2000 200725

30

35

40

45

50

55

60

Year

Pre

cip

itati

on (

inches)

Winter Spring

Summer

Fall

Precipitation Trends

2-Day 5-Year Event

1-Day Very Heavy Precipitation

Observed Trends in 1-day Very Heavy Precipitation (1958 to 2010)

NOAA/NCDC

Percent Change in 1-day Annual Maximum Obs Atmospheric Water Vapor

NOAA/NCDC

West Point, NY# of days with 2” or more Precipitation

Irene8/28/2011

72-h Precipitation (in) Ending at 8 AM 29 Aug 2011

Rainfall Associated with TC Irene

1-Day storm events on 8/28/2011

Slide Mtn: 8.62” = 200 yr storm event (8.03”) Rosendale: 8.52” = 100 yr storm event (7.37”) Mohonk Lake: 8.21” = 100yr storm event (7.36”)Walden: 6.65” = 50yr storm event (6.13”)

Projected Rainfall & Frequency of 100-year

storm

1-Day 20-Year Event

Climate Model Ensembles

67%

Average SummerHeat Index

# Days Over 90

Seasonality

Area with Snow Cover for at least 30 days

Under high emissions scenario

Source: CCSR

NYC

Troy

New York City Baseline (1971-2000) 2020s 2050s 2080s

Sea level rise(central range) NA + 2 to 5 in + 7 to 12 in + 12 to 23 in

Rapid Ice-MeltSea level rise NA ~ 5 to 10 in ~ 19 to 29 in ~ 41 to 55 in

Troy Baseline (1971-2000) 2020s 2050s 2080s

Sea level rise(Central range) NA + 1 to 4 in + 5 to 9 in + 8 to 18 in

Rapid Ice-MeltSea level rise NA ~ 4 to 9 in ~ 17 to 26 in ~ 37 to 50 in

Sea level rise

Figure 5.6. Hudson River Estuary with location of salt front on 10/30/2009, approximate distance is 53 river miles from the Battery at New York City (USGS).

•Rising sea level• slope of the river 2 ft/150 mi• sea level rise 1 in/decade • 0.6 mi up river/ year

•Reduced precip

•Increased temp (more evap)

Salt Front Migration

Flood-Producing Extreme Precipitation - Frontal systems

- Thunderstorms - Coastal storms - Nor’easters- Tropical storms

Other Factors – How will Climate Change affect these?

More Flooding?

- Rain-on-snow events- Geography- Antecedent soil conditions

Less Flooding?

- Snowmelt- Ice Jams- Rain-on-snow events- Antecedent soil conditions

No affect/Unknown? - Geography- Infrastructure- Impervious surfaces

Questions?

jlr98@cornell.eduwww.nrcc.cornell.eduPrecip.net

Time-series represents an areally weighted average of data from 56 stations in the Northeast that have been in operation continuously since 1900.

Data from the NOAA-NCDC (ftp://ftp.ncdc.noaa.gov/pub/data/ushcn).

Average Annual Temperature in the Northeast 1899-2000

Until 2012: 50.2

Average Annual Precipitation in the Northeast, 1899-2000

Time series represent average of 79 meteorological stations in the Northeast.