Intro 1
description
Transcript of Intro 1
![Page 1: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/1.jpg)
Part 1. Black Carbon in Arctic snow: concentrations and effect on surface albedo
Tom Grenfell & Steve WarrenUniversity of Washington
Tony Clarke (University of Hawaii)Vladimir Radionov (AARI, St. Petersburg)
Other UW participants:Dean Hegg, Richard Brandt,Sarah Doherty, Steve Hudson,
Mike Town, Hyun-Seung Kim, Lora Koenig, Ron Sletten (ESS) Jamie Morison, Andy Heiberg, Mike Steele (APL)
Project website: www.atmos.washington.edu/sootinsnowIntro 1
![Page 2: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/2.jpg)
Sn
ow A
lbed
o
0.5ppm 0.05ppm
5 ppm
5 ppm
0.05 ppm
0.5 ppm
Primary influence of BC on Spectral Albedo was first characterized by Warren and Wiscombe 1980.(i) visible wavelengths(ii) grain radius
![Page 3: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/3.jpg)
Where and when does variation of snow albedo matter for climate?
Whenever large areas of snow are exposed to significant solar energy
Arctic snow- Tundra in spring- Sea ice in spring (covered with snow)- Greenland Ice Sheet in spring (cold snow)- Greenland Ice Sheet in summer (melting snow)
Glacier ice and sea ice:- Ablation zone of Greenland Ice Sheet in summer- Arctic sea ice in summer
Non-Arctic snow- Great Plains of North America- Steppes of Asia: Kazakhstan, Mongolia, Xinjiang, Tibet
Where and when does this matter (?)
![Page 4: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/4.jpg)
Pioneering Effort – 1983/4 Survey
![Page 5: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/5.jpg)
1983
Soot in snow 1983-4 (Clarke & Noone) Most amounts are 5-50 parts per billion.
Clarke & Noone Sites
![Page 6: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/6.jpg)
Warren & Wiscombe (1985);
Warren &Clarke(1986)
Soot contents from Clarke & Noone (1985)
Expected magnitude of albedo reduction
![Page 7: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/7.jpg)
Difficulties in the use of remote sensing to determine BC's effect on snow albedo
1. It's hard to distinguish snow from clouds-over-snow, which hide the surface. Thin near-surface layers of atmospheric ice crystals ("diamond-dust") are common in the Arctic.
2. The bidirectional reflectance (BRDF) is affected by: a. small-scale surface roughness: ripples, sastrugi, suncups, pressure-ridges. (The effects of
sastrugi on BRDF are different at different wavelengths, because they depend on the ratio of sastrugi width to flux-penetration depth.)
b. when thin surface-fog (or diamond-dust layer) covers the rough snow, the forward peak is enhanced and the nadir view is darker. This darkening at nadir could be mistaken for BC contamination.
c. Grain shape
3. Albedo reduction by BC in snow can be mimicked by:- thin snow. Sooty snow has the same spectral signature as thin snow.
- increase of grain size with depth (common situation) preferentially reduces visible albedo - sub-grid-scale leads in the Arctic Ocean. - BC in the atmosphere above the snow (Arctic haze).
Difficulties with remote sensing
![Page 8: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/8.jpg)
Our 4-year project (begunin spring 2006): a comprehensive surface-based survey of BC in Arctic snow,to repeat and extend Clarke & Noone’ssurvey from 1983/4.
Our Sites
Yukon River
Baker Lake
Kugluktuk
Petermann
GITS
NASA-SE
SaddleDye-2
South D
Petermann ELASummit
NASA-E
Thule
SGW-NE
Nar'yan Mar
VorkutaNoril'sk
Khatanga
Dikson
Tiksi
Pevek
Anady r
Chersky
Uelen
Yakutsk
Magadan
50
N
60
N
70
N
80
N
90 N
![Page 9: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/9.jpg)
Sampling Profiles
![Page 10: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/10.jpg)
Filter Apparatus deployed in the field
![Page 11: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/11.jpg)
Filters are compared to standard calibration filters. They will be scanned with a spectrophotometer to quantify BC, dust, & other components – different spectral absorption curves.
Filters
![Page 12: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/12.jpg)
BC in snow (ppb)Median valuesK. Steffen automaticweather stations +
Greenland Sector
22
Petermann10
GITS6
NASA-SE1
Saddle
1
Dye-2
3->9
South D
7
Petermann ELA
1
Summit2
NASA-E
1
Thule4
SGW-NE
2
![Page 13: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/13.jpg)
BC in Snow (ppb)M. Sturm (CRREL)+
Canada Sector
Yukon River
15
7 25
10 5576712
70
156
812
2325
8179 5 10
6 1154 4 6
Baker Lake
Kugluktuk
3
5
9
22
3
7
5
3
7
4,6
150 W
140 W
130 W
120 W 110
W 100
W
90 W
80 W
70 W
60 N
70 N
80 N
90 N
![Page 14: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/14.jpg)
T. Grenfell and Steve Hudson, Western Arctic Russia March-May 2007Permissions were granted to enter restricted border areas; International Polar Year (IPY) has prominence in Russia.
Nar'yan Mar
10Vorkuta
220
Noril'skKhatanga
30
Dikson
9
Tiksi
Pevek
Anadyr
Chersky
Uelen
Yakutsk Magadan
45 E
75 E
105 E
135 E
165 E
50 N
60 N
70 N
80 N
Russian Sector
![Page 15: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/15.jpg)
Representative Profile - Khatanga
![Page 16: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/16.jpg)
IPY News Information Bulletin June 2007
Stephen Hudson (left), a graduate student at the University of Washington, traveling up the Khatanga River
Новости МПГ
![Page 17: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/17.jpg)
Table of Results*strong haze event
*
![Page 18: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/18.jpg)
(1) Do particles collect at the surface as the snow melts?
Greenland (Dye-2) August 2007, melting snow: surface 9 ppb, subsurface 3 ppb
Enhancements
(2) Snow grain size increases markedly with spring melt onset magnifying the effect of a given soot load – accelerating melt. Δ(albedo) changes from -0.01 to -0.03 for 35 ngC/g
![Page 19: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/19.jpg)
Spectral albedo of snow observed at selected sites for closure - soot observations, RT modeling, and spectral albedo. Svalbard, March 2007
![Page 20: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/20.jpg)
New Snow Loading and Scavenging Experiments - Tony Clarke
![Page 21: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/21.jpg)
January: Artificial snowpack to quantify effect of soot on snow albedo with homogeneous grain size and known BC loading - (Rich Brandt, Steve Warren – Adirondacks)
March-May: Snow sampling in Eastern Siberia (Grenfell & Warren)
April: Albedo & BC intercomparison with Norwegian Polar Institute (Gerland, Brandt)
April-May: Redistribution of BC during melt (Sanja Forsstrøm at Tromsø)
July: Greenland melting-snow zone: redistribution study - fine vertical BC sampling of top 20 cm; spectral albedo (Brandt & Warren)
Calibrate new spectrophotometer; quantify BC, dust, other components (Sarah Doherty, Tom Grenfell); further comparisons with SP2 (Joe McConnell, Tony Clarke)
Scanning Electron Microscope and chemical analysis of samples to investigate source signatures (Hegg, Grenfell, Warren)
Plans for 2008
![Page 22: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/22.jpg)
Jim Hansen for inspiring us to take on this project
Clean Air Task Force and NSF Arctic Program for support
Thanks to:
![Page 23: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/23.jpg)
This project has benefited from the increased scientific activity in the Arctic, 2007-9.
Collaborations:Norwegian Polar Institute (Svalbard) Sebastian GerlandDanish Polar Center (Northeast Greenland) Carl-Egede Bøggild Arctic and Antarctic Research Institute (Russia) Vladimir Radionov Volunteers who have collected snow for this project in 2007:
Konrad Steffen & Thomas Phillips (Univ. Colorado). Automatic weather stations in GreenlandMatthew Sturm (U.S. Army Cold Regions Lab, Fairbanks, Alaska). Snowmobile traverse of Arctic Alaska and CanadaJacqueline Richter-Menge (U.S. Army Cold Regions Lab, Hanover, NH). Snow on sea ice in the Beaufort SeaJamie Morison, Andy Heiberg & Mike Steele (UW Applied Physics Lab). North Pole Environmental Observatory and Switchyard Expt, Arctic Ocean.Matt Nolan (Univ. Alaska). McCall Glacier, northern AlaskaVon Walden (Univ. Idaho). Ellesmere Island, CanadaShawn Marshall (Univ. Calgary). Devon Island Ice Cap, Canada.
International Polar Year Collaborations
![Page 24: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/24.jpg)
Part 2. Source Attribution of Black Carbon in Arctic SnowDean Hegg, Tom Grenfell, Steve Warren
U. of Washington, Seattle, WA
Yukon River
Baker Lake
Kugluktuk
Petermann
GITS
NASA-SE
SaddleDye-2
South D
Petermann ELASummit
NASA-ESGW-NE
Nar'yan Mar
VorkutaNoril'sk
Khatanga
Dikson
Tiksi
Pevek
Anadyr
Chersky
Uelen
Yakutsk
Magadan
50
N
60
N
70
N
80
N
90 N
![Page 25: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/25.jpg)
Current Data Base
• 36 sites - Canada, Greenland, Russia, North Pole
• BC estimates from filter samples
• 26 soluble co-analytes from filtered, melted snow
a. Anions – ion chromatography
b. Hydrocarbons – liquid chromatography, mass spectrometer detection
c. Elements – ICP-OES (inductively coupled plasma with optical emission spectroscopy)
![Page 26: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/26.jpg)
BC concentration, 3 most highly correlated analytes, and a biomass fire tracer (Levoglucosan)
Levoglucosan is not simply correlated with BC but is identified by the factor analysis.
![Page 27: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/27.jpg)
PMF (Positive matrix factorization) model results (tentative) for available data base. The five most significant factors explained 90% of variance.
90 % of the mass of BC is associated with this and the next factor.
![Page 28: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/28.jpg)
PMF Results continued. Factor shown had next highest BC loading. These two factors accounted for over 90% of the BC
90 % of the mass of BC is associated with this and the previous factor.
![Page 29: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/29.jpg)
Preliminary Interpretation•Both factors had appreciable levoglucosan, suggesting a strong biomass component to the BC
![Page 30: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/30.jpg)
Preliminary Interpretation•Both factors had appreciable levoglucosan, suggesting a strong biomass component to the BC•The 1st factor was associated primarily with the Russian sites, the 2nd with the Canadian sites
![Page 31: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/31.jpg)
Preliminary Interpretation•Both factors had appreciable levoglucosan, suggesting a strong biomass component to the BC•The 1st factor was associated primarily with the Russian sites, the 2nd with the Canadian sites•Both factors also indicated a pollution component of different composition for the two locales. This is expected and may be a geographic discriminator.• More species are needed to explore the attribution in detail.
![Page 32: Intro 1](https://reader034.fdocuments.net/reader034/viewer/2022051316/5681555e550346895dc327d8/html5/thumbnails/32.jpg)
Further Analysis• Analysis of non-filtered snow melt
• Chemical analysis of snow filters for insoluble tracers.
• In particular, analysis of filter deposits for PAH’s (polycyclic aromatic hydrocarbons).
• More elaborate receptor modeling